This document appears to be a dissertation submitted for a Master's degree in digital communication engineering. It discusses comparative analysis of wavelet packet based MC-CDMA and conventional MC-CDMA systems. The dissertation includes sections on literature review, wavelet packets, MC-CDMA systems, wavelet packet based MC-CDMA system, performance measures, methodology, and expected outcomes. The student conducted this research under the guidance of their supervisor.
This document is a dissertation that proposes a wavelet packet based MC-CDMA system and compares its performance to a conventional MC-CDMA system using HHT tool. It first provides background on conventional MC-CDMA and its components. It then introduces wavelet packets and describes how they can be used to create a wavelet packet based MC-CDMA system. The document outlines the methodology that will be used to simulate both systems over an AWGN channel and compare their bit error rate, mean square error, and peak signal to noise ratio to determine if the wavelet packet system performs better. The expected outcome is that the wavelet packet based MC-CDMA system will have superior performance to the conventional MC-CDMA
IRJET- Review on Multiple Access Techniques used in Mobile Telecommunication ...IRJET Journal
This document reviews the multiple access techniques used across different generations of mobile telecommunications. It discusses the key multiple access techniques of FDMA, TDMA, CDMA, and SDMA used in 1G-4G networks. It also covers packet switching methods like Aloha, slotted Aloha, CSMA/CD, CSMA/CA, and token ring. The techniques have evolved with each new generation to increase network capacity and accommodate more users through improvements like OFDMA and dynamic TDMA. In conclusion, the appropriate use of multiple access techniques is important for network communications by eliminating disadvantages and improving speed, accuracy, capacity and efficiency.
The document is a dissertation submitted for a Master of Technology degree focused on ATM basics for WCDMA networks. It includes a title page, certificate of approval from the supervisor, candidate's declaration, acknowledgements, table of contents, lists of abbreviations and symbols, and 12 chapters covering topics like ATM standards, the physical layer, ATM layer, adaptation layer, signaling, traffic descriptors, and quality of service parameters. The dissertation provides an in-depth technical overview of Asynchronous Transfer Mode (ATM) networking concepts as they relate to Wideband Code Division Multiple Access (WCDMA) wireless networks.
The document discusses chip level equalization techniques for W-CDMA systems. It presents two receiver architectures: (1) The conventional architecture which estimates the combined channel impulse response with one adaptive filter, but suffers from slow convergence. (2) The new architecture which estimates just the channel impulse response using a separate adaptive filter and faster chip-level training, improving convergence. Simulation results show the new architecture achieves better bit error rate performance than the conventional architecture, especially in dynamic user scenarios. The new architecture also allows use of lower complexity adaptive algorithms like NLMS.
Effect of Interleaved FEC Code on Wavelet Based MC-CDMA System with Alamouti ...IJCSEIT Journal
In this paper, the impact of Forward Error Correction (FEC) code namely Trellis code with interleaver on
the performance of wavelet based MC-CDMA wireless communication system with the implementation of
Alamouti antenna diversity scheme has been investigated in terms of Bit Error Rate (BER) as a function of
Signal-to-Noise Ratio (SNR) per bit. Simulation of the system under proposed study has been done in M-ary
modulation schemes (MPSK, MQAM and DPSK) over AWGN and Rayleigh fading channel incorporating
Walsh Hadamard code as orthogonal spreading code to discriminate the message signal for individual
user. It is observed via computer simulation that the performance of the interleaved coded based proposed
system outperforms than that of the uncoded system in all modulation schemes over Rayleigh fading
channel.
Diversity combining is a technique in wireless network that uses multiple antenna system to improve the quality of radio signal. Mobile radio system suffers multipath propagation due to signal obstruction in the channel. A new hybridized diversity combining scheme consisting of Equal Gain Combining (EGC) and Maximal Ratio Combining (MRC) was proposed in this paper. Theperformance of the hybrid model was evaluated using Outage Probability (Pout) and Processing time (Pt) at different Signal-to-Noise Ratio (SNR) and Signal Paths (L=2,3) for 4-QAM and 8-QAM Modulation Schemes. A mathematical expression for the hybrid EGC-MRC was realized using the Probability Density Function (PDF) of the Nakagami fading channel. MATLAB R2015b software was used for the model simulation. The result shows that hybrid EGC-MRC outperforms the standalone EGC and MRC schemes by having lower Pout and Pt values. Hence, hybrid EGC-MRC exhibits enhanced potentials to mitigate multipath propagation at reduced system complexity.
A NEW HYBRID DIVERSITY COMBINING SCHEME FOR MOBILE RADIO COMMUNICATION SYSTEM...ijcsit
Diversity combining is a technique in wireless network that uses multiple antenna system to improve the quality of radio signal. Mobile radio system suffers multipath propagation due to signal obstruction in the channel. A new hybridized diversity combining scheme consisting of Equal Gain Combining (EGC) and Maximal Ratio Combining (MRC) was proposed in this paper. Theperformance of the hybrid model was evaluated using Outage Probability (Pout) and Processing time (Pt) at different Signal-to-Noise Ratio (SNR) and Signal Paths (L=2,3) for 4-QAM and 8-QAM Modulation Schemes. A mathematical expression for the hybrid EGC-MRC was realized using the Probability Density Function (PDF) of the Nakagami fading channel. MATLAB R2015b software was used for the model simulation. The result shows that hybrid EGC-MRC outperforms the standalone EGC and MRC schemes by having lower Pout and Pt values. Hence, hybrid EGC-MRC exhibits enhanced potentials to mitigate multipath propagation at reduced
system complexity.
Performance evaluation of maximal ratio receiver combining diversity with pri...Alexander Decker
This document summarizes a research paper that evaluates the performance of Maximal Ratio Receiver Combining (MRRC) diversity with different interleavers for an Iterative Interleave-Division Multiple Access (IDMA) receiver. The paper finds that using MRRC diversity with one transmit and two receive antennas significantly improves the bit error rate performance of IDMA. It also finds that using a prime interleaver achieves similar performance to a random interleaver but with reduced bandwidth and memory requirements. The document introduces IDMA and describes the system model, interleaving techniques, and MRRC diversity approach that are evaluated through simulation to analyze the bit error rate performance of the IDMA system under different conditions.
This document is a dissertation that proposes a wavelet packet based MC-CDMA system and compares its performance to a conventional MC-CDMA system using HHT tool. It first provides background on conventional MC-CDMA and its components. It then introduces wavelet packets and describes how they can be used to create a wavelet packet based MC-CDMA system. The document outlines the methodology that will be used to simulate both systems over an AWGN channel and compare their bit error rate, mean square error, and peak signal to noise ratio to determine if the wavelet packet system performs better. The expected outcome is that the wavelet packet based MC-CDMA system will have superior performance to the conventional MC-CDMA
IRJET- Review on Multiple Access Techniques used in Mobile Telecommunication ...IRJET Journal
This document reviews the multiple access techniques used across different generations of mobile telecommunications. It discusses the key multiple access techniques of FDMA, TDMA, CDMA, and SDMA used in 1G-4G networks. It also covers packet switching methods like Aloha, slotted Aloha, CSMA/CD, CSMA/CA, and token ring. The techniques have evolved with each new generation to increase network capacity and accommodate more users through improvements like OFDMA and dynamic TDMA. In conclusion, the appropriate use of multiple access techniques is important for network communications by eliminating disadvantages and improving speed, accuracy, capacity and efficiency.
The document is a dissertation submitted for a Master of Technology degree focused on ATM basics for WCDMA networks. It includes a title page, certificate of approval from the supervisor, candidate's declaration, acknowledgements, table of contents, lists of abbreviations and symbols, and 12 chapters covering topics like ATM standards, the physical layer, ATM layer, adaptation layer, signaling, traffic descriptors, and quality of service parameters. The dissertation provides an in-depth technical overview of Asynchronous Transfer Mode (ATM) networking concepts as they relate to Wideband Code Division Multiple Access (WCDMA) wireless networks.
The document discusses chip level equalization techniques for W-CDMA systems. It presents two receiver architectures: (1) The conventional architecture which estimates the combined channel impulse response with one adaptive filter, but suffers from slow convergence. (2) The new architecture which estimates just the channel impulse response using a separate adaptive filter and faster chip-level training, improving convergence. Simulation results show the new architecture achieves better bit error rate performance than the conventional architecture, especially in dynamic user scenarios. The new architecture also allows use of lower complexity adaptive algorithms like NLMS.
Effect of Interleaved FEC Code on Wavelet Based MC-CDMA System with Alamouti ...IJCSEIT Journal
In this paper, the impact of Forward Error Correction (FEC) code namely Trellis code with interleaver on
the performance of wavelet based MC-CDMA wireless communication system with the implementation of
Alamouti antenna diversity scheme has been investigated in terms of Bit Error Rate (BER) as a function of
Signal-to-Noise Ratio (SNR) per bit. Simulation of the system under proposed study has been done in M-ary
modulation schemes (MPSK, MQAM and DPSK) over AWGN and Rayleigh fading channel incorporating
Walsh Hadamard code as orthogonal spreading code to discriminate the message signal for individual
user. It is observed via computer simulation that the performance of the interleaved coded based proposed
system outperforms than that of the uncoded system in all modulation schemes over Rayleigh fading
channel.
Diversity combining is a technique in wireless network that uses multiple antenna system to improve the quality of radio signal. Mobile radio system suffers multipath propagation due to signal obstruction in the channel. A new hybridized diversity combining scheme consisting of Equal Gain Combining (EGC) and Maximal Ratio Combining (MRC) was proposed in this paper. Theperformance of the hybrid model was evaluated using Outage Probability (Pout) and Processing time (Pt) at different Signal-to-Noise Ratio (SNR) and Signal Paths (L=2,3) for 4-QAM and 8-QAM Modulation Schemes. A mathematical expression for the hybrid EGC-MRC was realized using the Probability Density Function (PDF) of the Nakagami fading channel. MATLAB R2015b software was used for the model simulation. The result shows that hybrid EGC-MRC outperforms the standalone EGC and MRC schemes by having lower Pout and Pt values. Hence, hybrid EGC-MRC exhibits enhanced potentials to mitigate multipath propagation at reduced system complexity.
A NEW HYBRID DIVERSITY COMBINING SCHEME FOR MOBILE RADIO COMMUNICATION SYSTEM...ijcsit
Diversity combining is a technique in wireless network that uses multiple antenna system to improve the quality of radio signal. Mobile radio system suffers multipath propagation due to signal obstruction in the channel. A new hybridized diversity combining scheme consisting of Equal Gain Combining (EGC) and Maximal Ratio Combining (MRC) was proposed in this paper. Theperformance of the hybrid model was evaluated using Outage Probability (Pout) and Processing time (Pt) at different Signal-to-Noise Ratio (SNR) and Signal Paths (L=2,3) for 4-QAM and 8-QAM Modulation Schemes. A mathematical expression for the hybrid EGC-MRC was realized using the Probability Density Function (PDF) of the Nakagami fading channel. MATLAB R2015b software was used for the model simulation. The result shows that hybrid EGC-MRC outperforms the standalone EGC and MRC schemes by having lower Pout and Pt values. Hence, hybrid EGC-MRC exhibits enhanced potentials to mitigate multipath propagation at reduced
system complexity.
Performance evaluation of maximal ratio receiver combining diversity with pri...Alexander Decker
This document summarizes a research paper that evaluates the performance of Maximal Ratio Receiver Combining (MRRC) diversity with different interleavers for an Iterative Interleave-Division Multiple Access (IDMA) receiver. The paper finds that using MRRC diversity with one transmit and two receive antennas significantly improves the bit error rate performance of IDMA. It also finds that using a prime interleaver achieves similar performance to a random interleaver but with reduced bandwidth and memory requirements. The document introduces IDMA and describes the system model, interleaving techniques, and MRRC diversity approach that are evaluated through simulation to analyze the bit error rate performance of the IDMA system under different conditions.
11.performance evaluation of maximal ratio receiver combining diversity with ...Alexander Decker
The document evaluates the performance of Maximal Ratio Receiver Combining (MRRC) diversity technique for an Interleave-Division Multiple Access (IDMA) receiver with single transmit and two receive antennas. Simulation results show that MRRC diversity provides significant improvement to the bit error rate (BER) performance of IDMA. The BER performance of an IDMA system using a prime interleaver is found to be similar to one using a random interleaver, but with reduced bandwidth and memory requirements.
IRJET- Channel and Rate Selection in Cognitive Radio NetworkIRJET Journal
This document summarizes channel and rate selection techniques in cognitive radio networks. It discusses three main types of channel selection algorithms: fixed, hybrid, and dynamic. It also summarizes two specific techniques:
1) Using multi-armed bandits to formulate channel and rate selection as a stochastic optimization problem to maximize successful packet transmissions over time. The technique involves learning transmission probabilities on different channel-rate pairs through trials.
2) Using an upper confidence bound (UCB) algorithm for channel selection, where a secondary user selects channels based on both estimated throughput and uncertainty to balance exploitation and exploration of channels.
Coverage of WCDMA Network Using Different Modulation Techniques with Soft and...ijcnac
The wideband code division multiple access (WCDMA) based 3G cellular mobile
wireless networks are expected to provide a diverse range of multimedia services to
mobile users with guaranteed quality of service (QoS). To serve diverse quality of service
requirements of these networks it necessitates new radio resource management strategies
for effective utilization of network resources with coding schemes. In this paper coverage
area for voice traffic and with different modulation techniques, coding schemes and
decision decoder are discussed. These discussions are to improve the coverage area in
the mobile communication system. This paper is mainly focuses on coverage area of
WCDMA system using link budget calculation with different modulation, coding schemes
and decision decoder. Simulation results demonstrate coverage extension for voice
service with different modulation,coding scheme, soft and hard decision decoder using
appropriate Bit error rate (BER) to maintain QoS of the voice.
Comparative study of_digital_modulation (1)Bindia Kumari
This document compares different digital modulation techniques that can be used in orthogonal frequency division multiplexing (OFDM) and WiMAX networks. It simulates BPSK, QPSK, 16-QAM and 64-QAM modulation in MATLAB and measures their performance in terms of bit error rate and throughput. The results show that higher order modulations like 64-QAM provide much higher throughput but also higher bit error rates compared to lower order modulations at a given signal-to-noise ratio. The best configuration balances low bit error rates and high throughput.
IRJET- A Novel Technique for the Transmission of Digital Data through Ban...IRJET Journal
This document presents a novel technique for transmitting digital data through a bandlimited channel using a multi-antenna approach in the presence of channel fading. The technique utilizes multiple input multiple output (MIMO) with 4 antennas at the transmitter and receiver. It implements space shift keying (SSK) to convey data by activating different transmitter antennas, reducing complexity compared to conventional modulation schemes. Experimental results showed the technique can increase data transmission rates while introducing no errors at the receiver over a wireless fading channel.
Performance evaluation of VLC system using new modulation approachjournalBEEI
This document evaluates the performance of a new modulation scheme called catenated-OFDM for visible light communications (VLC) systems. Catenated-OFDM involves transmitting multiple OFDM signals simultaneously over different optical bands. The proposed system is simulated using Optisys software. Results show the system can achieve transmission distances of up to 12 meters for 2 dBm input power with 3 optical bands and a data rate of 10 Gbps. Higher data rates, up to 15 Gbps, are also possible. Increasing the number of optical bands or decreasing the data rate improves the receiver sensitivity. The catenated-OFDM approach shows potential for high-speed optical wireless communications.
Design of 4x4 optical MIMO using spatial ModulationSachin Talakeri
Utilizing illuminating LED arrays for visible light communication (VLC) in an indoor environment, an optical multiple-input multiple-output (MIMO) system has intrigued great interest. In order to increase the potential VLC data rates, multiple-input multiple-output (MIMO) systems have been proposed. MIMO schemes show the spectral efficiency improvement using spatial modulation
The document discusses multi-user CDMA communication using MATLAB. It introduces multiple access techniques such as FDMA, TDMA, SDMA and CDMA that allow multiple users to utilize the same bandwidth. CDMA uses direct sequence spread spectrum that spreads the message signal over a wider bandwidth using a PN code. The document discusses various spreading codes used in CDMA like maximal length sequences, Gold codes and Walsh codes. It then describes multiple access techniques in detail, including FDMA, TDMA, SDMA and CDMA. The block diagram of a DS-SS system is also presented.
Improving quality of service using ofdm technique for 4 th generation networkeSAT Publishing House
This document summarizes a research paper that compares the performance of 32QAM and 64QAM digital modulation techniques when used with OFDM for 4G networks. It finds that 32QAM has better performance with lower bit and packet loss over 64QAM. Specifically, when transmitting 1920 bits over an AWGN channel, 32QAM had 65 bit losses and 0 packet losses, while 64QAM had 80 bit losses and 0.04167 packet losses. Therefore, the document concludes 32QAM can be more efficiently used than 64QAM for digital transmission in 4G networks when combined with OFDM modulation.
Performance analysis of negative group delay network using MIMO techniqueTELKOMNIKA JOURNAL
This study introduces comparative consequences that determine the bit error rate enhancements, resultant from adopting a proposed MIMO wireless model in this study. The antenna configurations for this model uses new small microstrip slotted patch antenna with multiple frequency bands at strategic operating frequencies of 2.4, 4.4, and 5.55 respectively. The S11 response of the proposed antenna for IEEE802.11 MIMO wireless network has been highly appropriate to be adopted with MIMO antenna system. The negative group delay (NGD) response is the most significant feature for projected MIMO antenna. The NGD stands for a counterintuitive singularity that interacts time advancement with wave propagation. These improvements are employed for increasing a reliability of instantly conveyed data streams, enhance the capacity of the wireless configuration and decrease the bit error rate (BER) of adopted wireless system. In addition to antenna scattering response, the enhancements have been analysed in term of BER for different MIMO topologies.
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
This document describes a project report submitted by Revuru Gopikrishna for the degree of Bachelor of Technology in Electronics and Communications Engineering from Rajiv Gandhi University of Knowledge Technologies in May 2015. The project investigates reducing the peak-to-average power ratio in OFDM systems using nonlinear companding techniques. The report provides background on OFDM, discusses the problem of high PAPR in OFDM, and proposes using A-law and μ-law companding to compress the OFDM signal at the transmitter and expand it at the receiver in order to reduce PAPR.
Spectrally efficient multicarrier modulation system for visible light communi...IJECEIAES
Visible Light Communication (VLC) has become an accolade to its radio frequency counterpart. In VLC system, orthogonal frequency division multiplexing (OFDM) has drawn much attention, because of simple equalization, high spectral efficiency, high data rate and robustness to intersymbol interference (ISI). Besides, there are emerging applications that ought to be gotten with low latency and high reliability. To diminish power requirements with no transmission capacity extension, Trellis coded modulation (TCM) is utilized as a part of the framework in which the free distance of trellis diagram is equivalent to the minimum distance between the points of constellation focuses in partitioned subsets, which augments the coding gain up i.e. the performance parameter viably. TCM together with VLC-OFDM enhances the transmission execution in reasonable frameworks. In this paper, we propose OFDM which is based on TCM and is planned and exeuted for digitized OFDM frameworks by presenting delta sigma modulation (DSM) considering VLC channel. Simulation results show that the proposed TCM based VLC-OFDM offers incredible robustness against noises and nonlinear degradation.
THE PERFORMANCE OF CONVOLUTIONAL CODING BASED COOPERATIVE COMMUNICATION: RELAYIJCNCJournal
Wireless communication faces adversities due to noise, fading, and path loss. Multiple-Input MultipleOutput (MIMO) systems are used to overcome individual fading effect by employing transmit diversity. Duo to user single-antenna, Cooperation between at least two users is able to provide spatial diversity. This paper presents the evaluation of the performances of the Amplify and Forward (AF) cooperative system for different relay positions using several network topologies over Rayleigh and Rician fading channel. Furthermore, we present the performances of AF cooperative system with various power allocation. The results show that cooperative communication with convolutional coding shows an outperformance compared to the non-convolutional, which is a promising solution for high data-rate networks such as (WSN), Ad hoc, (IoT), and even mobile networks. When topologies are compared, the simulation shows that, linear topology offers the best BER performance, in contrast when the relay acts as source and the source take the relay place, the analysis result shows that, equilateral triangle topology has the best BER performance and stability, and the system performance with inter-user Rician fading channel is better than the performance of the system with inter-user Rayleigh fading channel.
International Journal of Engineering and Science Invention (IJESI) is an international journal intended for professionals and researchers in all fields of computer science and electronics. IJESI publishes research articles and reviews within the whole field Engineering Science and Technology, new teaching methods, assessment, validation and the impact of new technologies and it will continue to provide information on the latest trends and developments in this ever-expanding subject. The publications of papers are selected through double peer reviewed to ensure originality, relevance, and readability. The articles published in our journal can be accessed online.
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
International Journal of Computational Engineering Research (IJCER) ijceronline
International Journal of Computational Engineering Research(IJCER) is an intentional online Journal in English monthly publishing journal. This Journal publish original research work that contributes significantly to further the scientific knowledge in engineering and Technology
Implementation Cost Analysis of the Interpolator for the Wimax Technologyiosrjce
The design of the multirate filter (programmable) has been proposed which can be used in digital
transceivers that meets 802.16d/e (wimax) standard in the wireless communication system. Wimax is a
technology emerging in the wireless communication system in order to increase the broadband wireless internet
access. As there is wide spread need of the digital representation of the signal for the transmission and storage
which create the challenges in DSP [1]. In this paper, analysis of the implementation cost of interpolator for the
wimax technology, and cost of interpolator is analyzed on the basis of number of adders and multiplier. The
Filters are designed using the FDA (filters design and analysis) tool in MATLAB.
Analysis of Simulation Parameters of Pulse Shaping FIR Filter for WCDMAijsrd.com
The application of signal processing techniques to wireless communications is an emerging area that has recently achieved dramatic improvement in results and holds the potential for even greater results in the future as an increasing number of researchers from the signal process and communications areas participate in this expanding field. From an industrial viewpoint also, the advanced signal processing technology cannot only dramatically increase the wireless system capacity but can also improve the communication quality including the reduction of all types of interference. The present paper deals with simulation model of square root raised cosine pulse shaping filter for WCDMA with different parameters of the filter at 5Mhz.The present paper deals with study of Simulation Parameters (Number of Bits, Number of Errors) of Pulse Shaping FIR Filter at different value of group delay(2,4,6,8) to the calculate BER for WCDMA.
This document describes a space-time block coding (STBC) orthogonal frequency-division multiplexing (OFDM) system for text message transmission over fading channels using multiple transmit antennas. It evaluates the bit error rate (BER) performance of the system using different digital modulation schemes (BPSK, QPSK, QAM-8) over additive white Gaussian noise (AWGN) channels and fading channels. Low-density parity-check (LDPC) coding is concatenated with convolutional coding in the system to improve error performance. Simulation results show that the system is effective in retrieving the transmitted text message under noise and fading conditions, and that BER performance degrades with increasing noise power as expected.
This document is a dissertation submitted for a Master of Technology degree focused on ATM basics for WCDMA networks. It includes a title page, certificate of approval from the supervisor, candidate's declaration, acknowledgements, table of contents, lists of abbreviations and symbols, and 12 chapters covering topics like ATM standards, the physical layer, ATM layer, adaptation layer, signaling, traffic descriptors, and quality of service parameters. The dissertation provides a comprehensive overview of Asynchronous Transfer Mode (ATM) technology as it relates to 3G wireless networks.
This document contains the contents page of a thesis. It lists the chapters, sections, figures, and tables that are included in the thesis. The contents include an introduction, literature review, theoretical background on MC-CDMA systems, conventional, wavelet-based, and HHT-based MC-CDMA system models, results and discussions comparing the performance of the three systems, and a conclusion. Lists of abbreviations, symbols, figures, and tables are also provided.
11.performance evaluation of maximal ratio receiver combining diversity with ...Alexander Decker
The document evaluates the performance of Maximal Ratio Receiver Combining (MRRC) diversity technique for an Interleave-Division Multiple Access (IDMA) receiver with single transmit and two receive antennas. Simulation results show that MRRC diversity provides significant improvement to the bit error rate (BER) performance of IDMA. The BER performance of an IDMA system using a prime interleaver is found to be similar to one using a random interleaver, but with reduced bandwidth and memory requirements.
IRJET- Channel and Rate Selection in Cognitive Radio NetworkIRJET Journal
This document summarizes channel and rate selection techniques in cognitive radio networks. It discusses three main types of channel selection algorithms: fixed, hybrid, and dynamic. It also summarizes two specific techniques:
1) Using multi-armed bandits to formulate channel and rate selection as a stochastic optimization problem to maximize successful packet transmissions over time. The technique involves learning transmission probabilities on different channel-rate pairs through trials.
2) Using an upper confidence bound (UCB) algorithm for channel selection, where a secondary user selects channels based on both estimated throughput and uncertainty to balance exploitation and exploration of channels.
Coverage of WCDMA Network Using Different Modulation Techniques with Soft and...ijcnac
The wideband code division multiple access (WCDMA) based 3G cellular mobile
wireless networks are expected to provide a diverse range of multimedia services to
mobile users with guaranteed quality of service (QoS). To serve diverse quality of service
requirements of these networks it necessitates new radio resource management strategies
for effective utilization of network resources with coding schemes. In this paper coverage
area for voice traffic and with different modulation techniques, coding schemes and
decision decoder are discussed. These discussions are to improve the coverage area in
the mobile communication system. This paper is mainly focuses on coverage area of
WCDMA system using link budget calculation with different modulation, coding schemes
and decision decoder. Simulation results demonstrate coverage extension for voice
service with different modulation,coding scheme, soft and hard decision decoder using
appropriate Bit error rate (BER) to maintain QoS of the voice.
Comparative study of_digital_modulation (1)Bindia Kumari
This document compares different digital modulation techniques that can be used in orthogonal frequency division multiplexing (OFDM) and WiMAX networks. It simulates BPSK, QPSK, 16-QAM and 64-QAM modulation in MATLAB and measures their performance in terms of bit error rate and throughput. The results show that higher order modulations like 64-QAM provide much higher throughput but also higher bit error rates compared to lower order modulations at a given signal-to-noise ratio. The best configuration balances low bit error rates and high throughput.
IRJET- A Novel Technique for the Transmission of Digital Data through Ban...IRJET Journal
This document presents a novel technique for transmitting digital data through a bandlimited channel using a multi-antenna approach in the presence of channel fading. The technique utilizes multiple input multiple output (MIMO) with 4 antennas at the transmitter and receiver. It implements space shift keying (SSK) to convey data by activating different transmitter antennas, reducing complexity compared to conventional modulation schemes. Experimental results showed the technique can increase data transmission rates while introducing no errors at the receiver over a wireless fading channel.
Performance evaluation of VLC system using new modulation approachjournalBEEI
This document evaluates the performance of a new modulation scheme called catenated-OFDM for visible light communications (VLC) systems. Catenated-OFDM involves transmitting multiple OFDM signals simultaneously over different optical bands. The proposed system is simulated using Optisys software. Results show the system can achieve transmission distances of up to 12 meters for 2 dBm input power with 3 optical bands and a data rate of 10 Gbps. Higher data rates, up to 15 Gbps, are also possible. Increasing the number of optical bands or decreasing the data rate improves the receiver sensitivity. The catenated-OFDM approach shows potential for high-speed optical wireless communications.
Design of 4x4 optical MIMO using spatial ModulationSachin Talakeri
Utilizing illuminating LED arrays for visible light communication (VLC) in an indoor environment, an optical multiple-input multiple-output (MIMO) system has intrigued great interest. In order to increase the potential VLC data rates, multiple-input multiple-output (MIMO) systems have been proposed. MIMO schemes show the spectral efficiency improvement using spatial modulation
The document discusses multi-user CDMA communication using MATLAB. It introduces multiple access techniques such as FDMA, TDMA, SDMA and CDMA that allow multiple users to utilize the same bandwidth. CDMA uses direct sequence spread spectrum that spreads the message signal over a wider bandwidth using a PN code. The document discusses various spreading codes used in CDMA like maximal length sequences, Gold codes and Walsh codes. It then describes multiple access techniques in detail, including FDMA, TDMA, SDMA and CDMA. The block diagram of a DS-SS system is also presented.
Improving quality of service using ofdm technique for 4 th generation networkeSAT Publishing House
This document summarizes a research paper that compares the performance of 32QAM and 64QAM digital modulation techniques when used with OFDM for 4G networks. It finds that 32QAM has better performance with lower bit and packet loss over 64QAM. Specifically, when transmitting 1920 bits over an AWGN channel, 32QAM had 65 bit losses and 0 packet losses, while 64QAM had 80 bit losses and 0.04167 packet losses. Therefore, the document concludes 32QAM can be more efficiently used than 64QAM for digital transmission in 4G networks when combined with OFDM modulation.
Performance analysis of negative group delay network using MIMO techniqueTELKOMNIKA JOURNAL
This study introduces comparative consequences that determine the bit error rate enhancements, resultant from adopting a proposed MIMO wireless model in this study. The antenna configurations for this model uses new small microstrip slotted patch antenna with multiple frequency bands at strategic operating frequencies of 2.4, 4.4, and 5.55 respectively. The S11 response of the proposed antenna for IEEE802.11 MIMO wireless network has been highly appropriate to be adopted with MIMO antenna system. The negative group delay (NGD) response is the most significant feature for projected MIMO antenna. The NGD stands for a counterintuitive singularity that interacts time advancement with wave propagation. These improvements are employed for increasing a reliability of instantly conveyed data streams, enhance the capacity of the wireless configuration and decrease the bit error rate (BER) of adopted wireless system. In addition to antenna scattering response, the enhancements have been analysed in term of BER for different MIMO topologies.
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
This document describes a project report submitted by Revuru Gopikrishna for the degree of Bachelor of Technology in Electronics and Communications Engineering from Rajiv Gandhi University of Knowledge Technologies in May 2015. The project investigates reducing the peak-to-average power ratio in OFDM systems using nonlinear companding techniques. The report provides background on OFDM, discusses the problem of high PAPR in OFDM, and proposes using A-law and μ-law companding to compress the OFDM signal at the transmitter and expand it at the receiver in order to reduce PAPR.
Spectrally efficient multicarrier modulation system for visible light communi...IJECEIAES
Visible Light Communication (VLC) has become an accolade to its radio frequency counterpart. In VLC system, orthogonal frequency division multiplexing (OFDM) has drawn much attention, because of simple equalization, high spectral efficiency, high data rate and robustness to intersymbol interference (ISI). Besides, there are emerging applications that ought to be gotten with low latency and high reliability. To diminish power requirements with no transmission capacity extension, Trellis coded modulation (TCM) is utilized as a part of the framework in which the free distance of trellis diagram is equivalent to the minimum distance between the points of constellation focuses in partitioned subsets, which augments the coding gain up i.e. the performance parameter viably. TCM together with VLC-OFDM enhances the transmission execution in reasonable frameworks. In this paper, we propose OFDM which is based on TCM and is planned and exeuted for digitized OFDM frameworks by presenting delta sigma modulation (DSM) considering VLC channel. Simulation results show that the proposed TCM based VLC-OFDM offers incredible robustness against noises and nonlinear degradation.
THE PERFORMANCE OF CONVOLUTIONAL CODING BASED COOPERATIVE COMMUNICATION: RELAYIJCNCJournal
Wireless communication faces adversities due to noise, fading, and path loss. Multiple-Input MultipleOutput (MIMO) systems are used to overcome individual fading effect by employing transmit diversity. Duo to user single-antenna, Cooperation between at least two users is able to provide spatial diversity. This paper presents the evaluation of the performances of the Amplify and Forward (AF) cooperative system for different relay positions using several network topologies over Rayleigh and Rician fading channel. Furthermore, we present the performances of AF cooperative system with various power allocation. The results show that cooperative communication with convolutional coding shows an outperformance compared to the non-convolutional, which is a promising solution for high data-rate networks such as (WSN), Ad hoc, (IoT), and even mobile networks. When topologies are compared, the simulation shows that, linear topology offers the best BER performance, in contrast when the relay acts as source and the source take the relay place, the analysis result shows that, equilateral triangle topology has the best BER performance and stability, and the system performance with inter-user Rician fading channel is better than the performance of the system with inter-user Rayleigh fading channel.
International Journal of Engineering and Science Invention (IJESI) is an international journal intended for professionals and researchers in all fields of computer science and electronics. IJESI publishes research articles and reviews within the whole field Engineering Science and Technology, new teaching methods, assessment, validation and the impact of new technologies and it will continue to provide information on the latest trends and developments in this ever-expanding subject. The publications of papers are selected through double peer reviewed to ensure originality, relevance, and readability. The articles published in our journal can be accessed online.
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
International Journal of Computational Engineering Research (IJCER) ijceronline
International Journal of Computational Engineering Research(IJCER) is an intentional online Journal in English monthly publishing journal. This Journal publish original research work that contributes significantly to further the scientific knowledge in engineering and Technology
Implementation Cost Analysis of the Interpolator for the Wimax Technologyiosrjce
The design of the multirate filter (programmable) has been proposed which can be used in digital
transceivers that meets 802.16d/e (wimax) standard in the wireless communication system. Wimax is a
technology emerging in the wireless communication system in order to increase the broadband wireless internet
access. As there is wide spread need of the digital representation of the signal for the transmission and storage
which create the challenges in DSP [1]. In this paper, analysis of the implementation cost of interpolator for the
wimax technology, and cost of interpolator is analyzed on the basis of number of adders and multiplier. The
Filters are designed using the FDA (filters design and analysis) tool in MATLAB.
Analysis of Simulation Parameters of Pulse Shaping FIR Filter for WCDMAijsrd.com
The application of signal processing techniques to wireless communications is an emerging area that has recently achieved dramatic improvement in results and holds the potential for even greater results in the future as an increasing number of researchers from the signal process and communications areas participate in this expanding field. From an industrial viewpoint also, the advanced signal processing technology cannot only dramatically increase the wireless system capacity but can also improve the communication quality including the reduction of all types of interference. The present paper deals with simulation model of square root raised cosine pulse shaping filter for WCDMA with different parameters of the filter at 5Mhz.The present paper deals with study of Simulation Parameters (Number of Bits, Number of Errors) of Pulse Shaping FIR Filter at different value of group delay(2,4,6,8) to the calculate BER for WCDMA.
This document describes a space-time block coding (STBC) orthogonal frequency-division multiplexing (OFDM) system for text message transmission over fading channels using multiple transmit antennas. It evaluates the bit error rate (BER) performance of the system using different digital modulation schemes (BPSK, QPSK, QAM-8) over additive white Gaussian noise (AWGN) channels and fading channels. Low-density parity-check (LDPC) coding is concatenated with convolutional coding in the system to improve error performance. Simulation results show that the system is effective in retrieving the transmitted text message under noise and fading conditions, and that BER performance degrades with increasing noise power as expected.
This document is a dissertation submitted for a Master of Technology degree focused on ATM basics for WCDMA networks. It includes a title page, certificate of approval from the supervisor, candidate's declaration, acknowledgements, table of contents, lists of abbreviations and symbols, and 12 chapters covering topics like ATM standards, the physical layer, ATM layer, adaptation layer, signaling, traffic descriptors, and quality of service parameters. The dissertation provides a comprehensive overview of Asynchronous Transfer Mode (ATM) technology as it relates to 3G wireless networks.
This document contains the contents page of a thesis. It lists the chapters, sections, figures, and tables that are included in the thesis. The contents include an introduction, literature review, theoretical background on MC-CDMA systems, conventional, wavelet-based, and HHT-based MC-CDMA system models, results and discussions comparing the performance of the three systems, and a conclusion. Lists of abbreviations, symbols, figures, and tables are also provided.
This document contains the contents page of a thesis. It lists the chapters, sections, figures, and tables that are included in the thesis. The contents page includes the abstract and introduction chapters, as well as chapters on the theoretical background of MC-CDMA systems, the system model, results and discussions, and conclusions. It also lists references, publications, and an appendix.
Performance analysis of iterative idma scheme in power line communication usi...Alexander Decker
This document summarizes research analyzing the performance of an iterative IDMA (interleave division multiple access) scheme for power line communication. The IDMA model simulated uses BPSK modulation with k simultaneous users on a single-path power line channel. Convolution coding with a rate of 1/2 was used at the transmitter. Simulation results showed that increasing the data length and using coding improved the bit error rate performance of the IDMA system over power line channels. Coded IDMA achieved a lower bit error rate than uncoded IDMA.
PERFORMANCE OF MIMO MC-CDMA SYSTEM WITH CHANNEL ESTIMATION AND MMSE EQUALIZATIONTamilarasan N
The quality of a wireless link can be described by three basic parameters, namely transmission rate, transmission range
and transmission reliability. With the advent of multiple-input multiple-output (MIMO) assisted Multicarrier code
division multiple access (MC-CDMA) systems, the above-mentioned three parameters may be simultaneously
improved. The MC-CDMA combined with the MIMO technique, has become a core technology for future mobile radio
communication system. However, possible potential gain in spectral efficiency is challenged by the receiver’s ability to
accurately detect the symbol due to inter symbol interference (ISI). Multipath propagation, mobility of transmitter,
receiver and local scattering cause the signal to be spread in frequency, different arrival time and angle, which results in
ISI in the received signal. This will affect overall system performance. The use of MC-CDMA mitigates the problem of
time dispersion. However, still it is necessary to remove the amplitude and phase shift caused by channel. To solve this
problem, a multiple antenna array can be used at the receiver, not only for spectral efficiency or gain enhancement, but
also for interference suppression. This can be done by the, efficient channel estimation with strong equalization. This
paper proposes MIMO MC-CDMA system, Minimum mean square error (MMSE) equalization with pilot based
channel estimation. The simulation result shows improved Bit error rate (BER) performance when the sub carrier (SC)
and antenna configuration were increased
The document compares coding techniques used to mitigate interference in MU-MIMO systems. It discusses Zero Forcing, Block Diagonalization, Minimum Mean Square Error, and Signal to Leakage Noise Ratio algorithms. A MATLAB simulation was created to analyze the bit error rate performance of each algorithm with varying user numbers. Hardware testing using USRPs and LabVIEW validated the conclusions from the software simulation. It was found that MMSE and SLNR algorithms best addressed noise in the channel and had the lowest error rates, especially with increasing user numbers, due to their use of diversity techniques.
Differential equation fault location algorithm with harmonic effects in power...TELKOMNIKA JOURNAL
About 80% of faults in the power system distribution are earth faults. Studies to find effective methods to identify and locate faults in distribution networks are still relevant, in addition to the presence of harmonic signals that distort waves and create deviations in the power system that can cause many problems to the protection relay. This study focuses on a single line-to-ground (SLG) fault location algorithm in a power system distribution network based on fundamental frequency measured using the differential equation method. The developed algorithm considers the presence of harmonics components in the simulation network. In this study, several filters were tested to obtain the lowest fault location error to reduce the effect of harmonic components on the developed fault location algorithm. The network model is simulated using the alternate transients program (ATP)Draw simulation program. Several fault scenarios have been implemented during the simulation, such as fault resistance, fault distance, and fault inception angle. The final results show that the proposed algorithm can estimate the fault distance successfully with an acceptable fault location error. Based on the simulation results, the differential equation continuous wavelet technique (CWT) filter-based algorithm produced an accurate fault location result with a mean average error (MAE) of less than 5%.
1) The document presents a simulation of an MC-CDMA system using MSK modulation over AWGN and Rayleigh channels.
2) It shows that the BER performance of the MC-CDMA system is affected by both the number of users and the channel type, with higher numbers of users and Rayleigh fading increasing the BER.
3) The results also show that for both channel types, the MC-CDMA system has better BER performance when using MSK modulation compared to BPSK modulation.
IRJET- Power Line Carrier CommunicationIRJET Journal
This document describes power line carrier communication (PLCC), which uses power lines as a communication medium. It discusses using PLCC to transmit electricity billing data from individual homes to the electricity company without site visits. Key components of the system include a real-time clock, energy meter, microcontroller, LCD display, and FSK transmitter and receiver. Data transmission is done by modulating a signal onto the power line using FSK modulation. The system is intended to reduce the burden on electricity companies by allowing remote transmission of billing data without the need for site visits.
The document discusses the design and simulation of a 3.8 GHz narrow bandpass switched capacitor filter implemented in a 180 nm CMOS technology. It begins by introducing switched capacitor filters and their advantages over traditional resistor-based filters. It then describes the implementation of a two-stage CMOS operational amplifier used in the filter design. Simulation results showing the amplifier's gain characteristics are presented. The document concludes by presenting the schematic and simulation results of the 3.8 GHz bandpass filter designed using the two-stage op-amp.
International Journal of Engineering Research and Development (IJERD)IJERD Editor
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PERFORMANCE EVALUATION OF BER FOR AWGN, AWGN MULTIPATH AND RAYLEIGH FADING CH...IJEEE
This document evaluates the performance of bit error rate (BER) for different digital modulation techniques over additive white Gaussian noise (AWGN), AWGN multipath, and Rayleigh fading channels. It presents simulation results comparing the BER of binary phase-shift keying (BPSK) and quadrature phase-shift keying (QPSK) modulation under varying signal-to-noise ratio (SNR) levels for AWGN and AWGN multipath channels, and under varying Doppler shift levels for Rayleigh fading channels. The results show that BPSK has better BER performance than QPSK, and that BER is lowest for AWGN channels and highest for Rayleigh fading channels.
Implementation of Algorithms For Multi-Channel Digital Monitoring ReceiverIOSR Journals
Abstract: Monitoring Receivers form an important constituent of the Electronic support. In Monitoring
Receiver we can monitor, demodulate or scan the multiple channels.
In this project, the Implementation of algorithm for multi channel digital monitoring receiver. The
implementation will carry out the channelization by the way of Digital down Converters (DDCs) and Digital
Base band Demodulation. The Intermediate Frequency (IF) at 10.7 MHz will be digitalized using Analog to
Digital Converter (ADC) with sampling frequency 52.5 MHz and further converted to Base band using DDCs.
Virtually all the digital receivers perform channel access using a DDC. The Base band data will be streamed to
the appropriate demodulators. Matlab Simulink will be used to simulate the logic modules before the
implementation. This system will be prototyped on an FPGA based COTS (Commercial-off-the-shelf)
development board. Xilinx System Generator will be used for the implementation of the algorithms.
Keywords: DDC, ADC, Digital Base band demodulation, IF, Monitoring Receiver.
Transmitting audio via fiber optics under nonlinear effects and optimized tun...IJECEIAES
The ability of fiber optic to overcome the signal transmission problems is making it a dominant transmission medium. Despite of this major positive attribute of optic fibers, there is still a downside for using the fiber optic communication; that is the nonlinearity problem. For the first time, a design of an audio signal is suggested and executed in MATLAB with integration with OptiSystem TM Software .The audio signal then transmitted in different shapes of modulation signals (NRZ, RZ, & RC) for different distances (100 km & 75 km) via a fiber optic media to be received in a receiving part of the simulated system. Three tests are used to do so. The first is the Quality-facto (Q-Factor) against the received power, second test is eye diagram performance and finally is the measuring of the amplitude of output (received) signal for each modulation signal shape using the Oscilloscope Visualizer. The NZR modulation signal was found to be the best one of the three used signals’ types in all three tests. The Q-factor for NRZ pulse shape (=12) was higher than that for RZ (=10) and RC (=8) for a 100 km distance at the same received power level.
This document summarizes research on applying chaos theory to communications. It discusses using chaotic signals for spread spectrum communications due to their random, unpredictable properties. Chaotic signals can be generated using simple equations and have advantages like broad bandwidth, orthogonality, and security. Simulation results show chaos-based CDMA providing better bit error rate performance than PN sequences, especially with increasing numbers of users. Future research directions include studying different chaos generators, analysis tools for chaos theory, and applying chaos to technologies like 4G communications and home networks.
PERFORMANCE EVALUATION OF MC-CDMA SYSTEM OVER RAYLEIGH FADING CHANNELIJCSES Journal
Multi Carrier Code Division Multiple Access (MC-CDMA) is a well known technique for high speed
wireless data transmission .Two advanced technology was included in the MC-CDMA structure, such as
orthogonal frequency division multiplex (OFDM) and the code division multiple access (CDMA),so that it
benefits from the robustness of OFDM against multipath environment and from the capability of multiuser
multiplexing services that is achieved via (CDMA) system. MC-CDMA is a multicarrier spread spectrum
system which is classified as the candidate scheme for future mobile radio systems. In this paper MCCDMA
system, with Rayleigh fading channel and 16QAM array modulation, was simulated to investigate
the effects of different parameters on the system performance, such as processing gain; number of paths;
number of users; interleaving; and coding ratio.MC-CDMA performances can be considerably improved
by proper selection of these parameters. As expected, results show that MC-CDMA has a better performance over CDMA system.
Optimization channal contral power in live umts networkThananan numatti
Abstract— The proposed approach to improvement on the
UMTS (Universal Mobile Telecommunications System)
network radio, there are many ways we propose another way of
reducing power control channel slightly to provide improved
signal quality, which is a measure of quality is EcIo (energy per
bit) / (Own cell interference +. Noise density) principle when the
power control channel down a bit to make the quality better,
because the denominator less energy than ever before, and open
the extra capacity in the network in the body, this is the reason
for the optimization this principle can be applied in a live
network.
It is important to maintain signal quality are durable and
resistant to interference. Probability to the good benefits for
imply network must be physical tuning coverage complete before
and area dense urban or urban is good to the imply this
parameter. For area rural should not imply because the cell edge
a foot print coverage is too large . However this paper presents a science so that the results can be applied to real work.
This document provides a preface and disclaimer for a set of 2D and 3D CAD exercises. The preface outlines that the book contains 100 2D exercises and 50 3D exercises in CAD software like AutoCAD, SolidWorks, and Inventor. It notes each exercise can be done separately at any skill level and uses metric dimensions. The disclaimer states the exercises are for practice and not tutorials, and that no part of the publication may be reproduced without permission.
This document outlines the terms and conditions for a home loan agreement between John Doe and ABC Bank. It specifies that John Doe will receive a $200,000 loan at 4% annual interest to purchase a property located at 123 Main St. The loan is to be repaid over 30 years through monthly installments of $1,000 beginning on January 1, 2023, with the full balance due by December 31, 2052. The document details various clauses around late fees, prepayment, and foreclosure.
The document discusses the benefits of exercise for mental health. Regular physical activity can help reduce anxiety and depression and improve mood and cognitive functioning. Exercise causes chemical changes in the brain that may help protect against mental illness and improve symptoms.
The document provides an overview of Multi-Carrier Code Division Multiple Access (MC-CDMA) systems and discusses several related research papers. It then summarizes 21 research papers on topics such as: implementing space-time coding and discrete wavelet transforms in MC-CDMA systems to improve performance; using wavelet packets as modulation waveforms to eliminate guard intervals; flexible MC-CDMA system designs; and evaluating the performance of different wavelet transforms in MC-CDMA communications. The document analyzes various techniques for enhancing the spectral efficiency and performance of MC-CDMA systems.
The document is a 15,991-word literature review on MC-CDMA (multi-carrier code division multiple access) communication systems. It cites 106 different sources, including publications, internet sources, and student papers. The sources cover topics like MC-CDMA system design and performance analysis, modulation techniques for MC-CDMA, and comparisons with other multi-carrier systems.
This document summarizes a research project comparing wavelet packet based MC-CDMA with conventional MC-CDMA using the Hilbert-Huang transform tool. The research aims to show that wavelet packet based MC-CDMA has better bit error rate performance than conventional MC-CDMA in dealing with channel fading and interference. It provides background on MC-CDMA and wavelet packet techniques. It outlines the methodology which involves simulation using MATLAB and the Hilbert-Huang transform tool for spectral analysis. The expected outcome is that wavelet packet MC-CDMA will demonstrate comparative superiority over conventional MC-CDMA.
The document compares wavelet packet based MC-CDMA to conventional MC-CDMA. It proposes using wavelet packets instead of sinusoidal carriers for MC-CDMA. Wavelet packets have lower sidelobes, better time-frequency localization, and maintain orthogonality for overlapped signals. This improves performance by reducing interference and relaxing separation requirements between signals. Simulation results show the proposed wavelet packet based MC-CDMA outperforms conventional MC-CDMA, especially in combating fading channels.
This document discusses ATM basics for WCDMA networks. It describes the different network transfer modes including synchronous transfer mode, packet transfer mode, and asynchronous transfer mode. Asynchronous transfer mode is highlighted as a compromise that supports voice, video, and data over WCDMA networks by providing quality of service guarantees. Key aspects of ATM like cells, virtual paths, virtual connections, and service classes are defined. The document also outlines why ATM is used as the transport protocol in 3G networks.
This document discusses ATM basics for WCDMA networks. It describes the different network transfer modes including synchronous transfer mode, packet transfer mode, and asynchronous transfer mode. Asynchronous transfer mode is highlighted as a compromise that supports voice, video, and data over WCDMA networks by providing quality of service guarantees. Key aspects of ATM like cells, virtual paths, virtual connections, and service classes are defined. The document also outlines why ATM is used as the transport protocol in 3G networks.
This document summarizes the simulation steps for investigating the performance of three multi-carrier code division multiple access (MC-CDMA) techniques: conventional MC-CDMA, orthogonal wavelet packet based MC-CDMA (WP-MC-CDMA), and Huang Hilbert Transformation (HHT) based MC-CDMA. The steps include designing the three systems, simulating them with different modulation techniques under fading channels, and comparing their bit error rate performance. Numerical and simulation results are presented to validate the proposed schemes.
The document lists 9 publications by Manmohan Singh Chandoliya and Ms. Anila Dingra between 2014-2015. The publications analyze and compare wavelet packet based MC-CDMA communication systems with conventional MC-CDMA systems using different transforms and modulation techniques. Additional publications examine using multi-microcontroller communication for industrial control applications.
This document contains 37 references related to research on multi-carrier code division multiple access (MC-CDMA) communication systems. The references cover topics like MC-CDMA system design, performance analysis under different channel conditions, receiver design techniques, and comparisons with other digital communication systems. The references are from a variety of academic sources including IEEE journals and conference proceedings published between 1993 and 2008.
The document defines and describes several key terms related to digital signal processing and wireless communications:
- Hilbert-Huang Transform (HHT) is a technique to decompose non-stationary and non-linear time series data into intrinsic mode functions (IMFs) and obtain instantaneous frequency information.
- Orthogonal Frequency Division Multiplexing (OFDM) is a digital multi-carrier modulation technique that is widely used today.
- Bit Error Rate (BER) is the ratio of bit errors to total transmitted bits over a period of time and is used to measure communication quality.
- Quadrature Phase Shift Keying (QPSK) is a modulation scheme that encodes 2 bits per symbol by
The document discusses various literature on OFDM and MC-CDMA techniques. It summarizes 17 research papers on topics like using wavelet packets instead of Fourier transform in MC-CDMA to improve bandwidth efficiency and reduce interference. It also discusses using techniques like DWT, Radon transform, and antenna diversity with MC-CDMA and comparing the BER performance of different approaches in various channel conditions like AWGN, Rayleigh fading and frequency selective fading channels. The rationale given is that replacing Fourier transform with wavelet packets in MC-CDMA can eliminate the need for cyclic prefix and improve spectral efficiency.
The document provides an overview of Multi-Carrier Code Division Multiple Access (MC-CDMA) systems and discusses previous research in this area. It then proposes a new complex orthogonal wavelet packet based MC-CDMA system to investigate its bit error rate performance over different modulation techniques on an AWGN channel. The key aspects covered are:
1) MC-CDMA allows multiple users to transmit simultaneously by spreading user symbols across several subcarriers using different code values.
2) Previous research explored combining MC-CDMA with techniques like space-time coding and discrete wavelet transforms to improve performance.
3) The proposed system uses wavelet packet modulation waveforms instead of sinusoidal ones to eliminate guard intervals
This document investigates the performance of multi-carrier code division multiple access (MC-CDMA) systems. It compares the performance of conventional MC-CDMA, orthogonal wavelet packet based MC-CDMA (WP-MC-CDMA), and Huang Hilbert Transformation (HHT) based MC-CDMA in terms of bit error rate, throughput, and modulation techniques. The WP-MC-CDMA shows improvements over conventional MC-CDMA, while the HHT based MC-CDMA outperforms the other two as it uses instantaneous channel state information to analyze data more accurately, making it more spectrally efficient. Numerical and simulation results are presented to validate the proposed schemes.
The author thanks their supervisor, Mrs. Archana Mewara, for providing guidance and direction during their work. They also thank the principal of their university, Prof. Dr. Vishnu Sharma, for allowing them to complete their Master's program, and the head of their department, Mr. L. N. Balai, for providing software and lab access. Finally, the author expresses gratitude to the entire faculty and staff of the Electronics and Communication Engineering department for their encouragement and support during the dissertation process.
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TIME DIVISION MULTIPLEXING TECHNIQUE FOR COMMUNICATION SYSTEMHODECEDSIET
Time Division Multiplexing (TDM) is a method of transmitting multiple signals over a single communication channel by dividing the signal into many segments, each having a very short duration of time. These time slots are then allocated to different data streams, allowing multiple signals to share the same transmission medium efficiently. TDM is widely used in telecommunications and data communication systems.
### How TDM Works
1. **Time Slots Allocation**: The core principle of TDM is to assign distinct time slots to each signal. During each time slot, the respective signal is transmitted, and then the process repeats cyclically. For example, if there are four signals to be transmitted, the TDM cycle will divide time into four slots, each assigned to one signal.
2. **Synchronization**: Synchronization is crucial in TDM systems to ensure that the signals are correctly aligned with their respective time slots. Both the transmitter and receiver must be synchronized to avoid any overlap or loss of data. This synchronization is typically maintained by a clock signal that ensures time slots are accurately aligned.
3. **Frame Structure**: TDM data is organized into frames, where each frame consists of a set of time slots. Each frame is repeated at regular intervals, ensuring continuous transmission of data streams. The frame structure helps in managing the data streams and maintaining the synchronization between the transmitter and receiver.
4. **Multiplexer and Demultiplexer**: At the transmitting end, a multiplexer combines multiple input signals into a single composite signal by assigning each signal to a specific time slot. At the receiving end, a demultiplexer separates the composite signal back into individual signals based on their respective time slots.
### Types of TDM
1. **Synchronous TDM**: In synchronous TDM, time slots are pre-assigned to each signal, regardless of whether the signal has data to transmit or not. This can lead to inefficiencies if some time slots remain empty due to the absence of data.
2. **Asynchronous TDM (or Statistical TDM)**: Asynchronous TDM addresses the inefficiencies of synchronous TDM by allocating time slots dynamically based on the presence of data. Time slots are assigned only when there is data to transmit, which optimizes the use of the communication channel.
### Applications of TDM
- **Telecommunications**: TDM is extensively used in telecommunication systems, such as in T1 and E1 lines, where multiple telephone calls are transmitted over a single line by assigning each call to a specific time slot.
- **Digital Audio and Video Broadcasting**: TDM is used in broadcasting systems to transmit multiple audio or video streams over a single channel, ensuring efficient use of bandwidth.
- **Computer Networks**: TDM is used in network protocols and systems to manage the transmission of data from multiple sources over a single network medium.
### Advantages of TDM
- **Efficient Use of Bandwidth**: TDM all
Embedded machine learning-based road conditions and driving behavior monitoringIJECEIAES
Car accident rates have increased in recent years, resulting in losses in human lives, properties, and other financial costs. An embedded machine learning-based system is developed to address this critical issue. The system can monitor road conditions, detect driving patterns, and identify aggressive driving behaviors. The system is based on neural networks trained on a comprehensive dataset of driving events, driving styles, and road conditions. The system effectively detects potential risks and helps mitigate the frequency and impact of accidents. The primary goal is to ensure the safety of drivers and vehicles. Collecting data involved gathering information on three key road events: normal street and normal drive, speed bumps, circular yellow speed bumps, and three aggressive driving actions: sudden start, sudden stop, and sudden entry. The gathered data is processed and analyzed using a machine learning system designed for limited power and memory devices. The developed system resulted in 91.9% accuracy, 93.6% precision, and 92% recall. The achieved inference time on an Arduino Nano 33 BLE Sense with a 32-bit CPU running at 64 MHz is 34 ms and requires 2.6 kB peak RAM and 139.9 kB program flash memory, making it suitable for resource-constrained embedded systems.
Embedded machine learning-based road conditions and driving behavior monitoring
Project sinopsis final M.TECH ( PDF FILE )
1. 1
Comparative Analysis of Wavelet Packet Based MC-CDMA with
The Conventional MC-CDMA Using HHT Tool
A
Dissertation
submitted
in partial fulfillment
for the award of the Degree of
Master of Technology
in Department of Electronics & Communication Engineering
(with specialization in Digital Communication)
Supervisor: Submitted By:
Mrs. Archana Mewara Manmohan Singh Chandoliya
Asst. Professor Enrolment No.: 12E2YTDCM3XP603
( Department of Electronics & Comm. Engg.)
YIT, Jaipur
Department of Electronics & Communication Engineering
Yagyavalkya Institute of Technology
YIT Lane, RIICO Industrial Area
Sitapura, JAIPUR.
Rajasthan Technical University
March, 2018
2. 2
CERTIFICATE
This is to certify that Mr. MANMOHAN SINGH CHANDOLIYA a student of M .Tech. in
DIGITAL COMMUNICATION ( Electronics & communication Engineering / Electronic
Instrumentation & Control Engineering ) 3rd
semester has submitted her Dissertation synopsis
entitled ― Comparative Analysis of Wavelet Packet Based MC-CDMA With The
Conventional MC-CDMA Using HHT Tool ‖ under my guidance.
Mrs. Archana Mewara
Asst. Professor
Department of Electronics & Communication Engineering
Yagyavalkya Institute of Technology, Jaipur
3. 3
CANDIDATE’S DECLARATION
I hereby declare that the work, which is being presented in the Dissertation, entitled
―Comparative Analysis of Wavelet Packet Based MC-CDMA with the Conventional MC-
CDMA Using HHT Tool‖ in partial fulfillment for the award of Degree of ―Master of
Technology‖ in Department. of Electronics & Communication Engineering with
Specialization in Digital Communication, and submitted to the Department of Electronics &
Communication Engineering, Yagyavalkya Institute of Technology, Jaipur, Rajasthan
Technical University is a record of my own investigations carried under the Guidance of Mrs.
Archana Mewara, Asst. Professor, Department of Electronics & Communication
Engineering, Yagyavalkya Institute of Technology.
I have not submitted the matter presented in this Dissertation anywhere for the award of any
other Degree/Diploma.
(Name and Signature of Candidate)
( Manmohan Singh Chandoliya )
Digital Communication
Enrolment No. – 12E2YTDCM3XP603
Yagyavalkya Institute of Technology, Jaipur
Counter Signed by-
Mrs. Archana Mewara
Asst. Professor
Department of Electronics & Communication Engineering
Yagyavalkya Institute of Technology, Jaipur
4. 4
ACKNOWLEDGEMENT
I would like to thank my supervisor Mrs. Archana Mewara, Asst. Professor, Department of
Electronics and Communication Engineering for providing me opportunity to work under him
and his consistent direction, he has fed in my work. It’s my privilege to acknowledge my
profound sense of gratitude to my supervisor for his comments, suggestions, encouragement and
inspiring guidance throughout the course of the dissertation work.
I also wish to extend my thanks to Prof. Dr. Vishnu Sharma, Principal, YIT to give me an
opportunity to carry out my Master of Technology program.
I also wish to extend my sincere thanks to Mr. L. N. Balai, H.O.D., Department of Electronics
and Communication Engineering for providing software and laboratories as additional facilities
to do Master of Technology.
At last but not the least I would like to place on record my sincere gratitude to faculties & staff of
Department of Electronics and Communication Engineering for providing fruitful environment
and continuous encouragement throughout the course of completion of my dissertation.
With sincere thanks from
Manmohan Singh Chandoliya
Enrolment No. 12E2YTDCM3XP603
5. 5
CONTENTS
S.No. Content Page No.
Certificate 2
Candidate’s Declaration 3
Acknowledgement 4
Content 05-07
List of Abbreviations 08-10
List of Symbols 11-13
List of Figures 14
List of Tables 15
1 Abstract 16
2 Introduction 16
3 Literature Review 18
3.1 Conventional MC-CDMA System 18
3.1.1 Concept of CDMA 18
3.1.2 Multi Carrier Concept 19
3.2 Orthogonal frequency Division multiplexing (OFDM) 21
3.2.1 Advantages and Drawbacks of OFDM System 22
3.2.2 Advantages of OFDM System 22
3.2.3 Disadvantages of OFDM System 22
3.2.4 OFDM with Code Division Multiplexing ( OFDM-CDM ) 23
3.3 Power Control in CDMA 23
3.3.1 Two Factors Important for Power Control 23
3.4 Diagram of MC-CDMA System. 24
3.4.1 MC-CDMA System 25
3.4.2 MC-CDMA System Parameters 26
3.4.3 MC-CDMA Transmitter 26
3.4.4 MC-CDMA Receiver 27
4 Walsh-Hada Mard Codes 28
5 Additive White Gaussian Noise (AWGN) Channel 28
6. 6
6 Huang-Hilbert Transform ( HHT ) 29
6.1 Introduction of HHT 29
6.2 Introduction of EMD and IMF 29
6.3 Introduction of HAS 29
6.4 Hilbert Spectral Analysis (SPA ) 29
6.5 Bit Error Rate ( BER ) 30
6.6 Mean Square Error ( MSE ) 30
6.7 Peak Signal to Noise Ratio ( PSNR ) 30
7 MC-CDMA System 30
7.1 Advantages of MC- CDMA System 30
7.2 Disadvantages of MC-CDMA System 31
7.3 Application of MC-CDMA System 31
8 Wavelet Packets Based MC-CDMA System 32
8.1 Wavelet Packets Based Communication System 32
8.2 Wavelet and Wavelet Transform 32
8.3 Wavelet Packets Based MC-CDMA System 33
8.4 Characteristics of Wavelet Packets 33
8.4.1 Wavelet Packets and Their Characteristics 33
8.4.2 Wavelet and Wavelet Packets Application in Communication 33
9 Detection Method 35
9.1 Conventional Signal User Detection 36
9.2 Multi-User Detection 37
10 Performance Measures 38
11 Wavelet Based Multi-Carrier Communication 39
11.1 Transmitter of WP MC-CDMA System 39
11.2 Receiver of WP MC-CDMA System 40
11.3 Wavelet Packets Based Different Modulation Techniques 41
12 Comparisons between Conventional MC-CDMA and WP MC-CDMA system 41
13 Literature Survey 42-49
14 Rationale 49
15 Problem Statement 49
7. 7
16 Methodology 49
17 Expected Outcomes 50
18 Conclusion 50
19 Progress So Far 51
Glossary & Keywords 52-55
References 56-59
List of Publications 60-61
Appendix 62-70
8. 8
LIST OF ABBREVIATIONS
ACF Auto-Correlation Function
ACI Adjacent Channel Interference
A/D Analogue/Digital ( Converter )
AGC Automatic Gain Control
AK Authorization Key
ARIB Association of Radio Industries and Businesses
ASIC Application Specific Integrated Circuit
ASN Access Service Network
A-TDMA Advanced TDMA
AWGN Additive White Gaussian Noise
B3G Beyond 3G
BER Bit Error Rate
BPSK Binary Phase Shift Keying
BWA Broadband Wireless Access
CA Certification Authority
CCI Co-Channel Interference
CDM Code Division Multiplexing
CDMA Code Division Multiple Access
CDMA-S2000 Code Division Multiple Access Standard 2000.
C/N Carrier-to-Noise Power Ratio
C/(N+I) Carrier-to-Noise and -Interference Power Ratio
CSI Channel State Information
D/A Digital/Analogue (converter)
DECT Digital Enhanced Cordless Telecommunications
DFT Discrete Fourier Transform
DFTS-OFDM DFT-Spread OFDM
DL Downlink
D-QPSK Differential-QPSK
DS Direct Sequence (DS-CDMA)
DSP Digital Signal Processor
9. 9
DVB Digital Video Broadcasting
EDGE Enhanced Data for Global Evolution
EGC Equal Gain Combining
EGT Equal Gain Transmission
ETSI European Telecommunication Standard Institute
FDMA Frequency Division Multiple Access
FEC Forward Error Correction
FFT Fast Fourier Transform
FH-CDMA Frequency Hopping (FH-CDMA)
GMSK Gaussian Minimum Shift Keying
GSM Global System for Mobile Communications
HHT Hilbert Huang Transform
HT Hilbert Transform
ICI Inter-Carrier Interference
IDFT Inverse Discrete Fourier Transform
IEEE Institute of Electrical and Electronics Engineers
IFFT Inverse Fast Fourier Transform
IHT Inverse Hada-Mard Transform
ISI Inter-Symbol Interference
MA Multiple Access
MAI Multiple Access Interference
MC Multi-Carrier
MC-CDMA Multi-Carrier CDMA
MCM Multi-Carrier Modulation
MC-SS Multi-Carrier Spread Spectrum
MC-TDMA Multi-Carrier TDMA (OFDM and TDMA)
M-QAM QAM Constellation With M Points, e.g. 16-QAM
MRC Maximum Ratio Combining
OFCDM Orthogonal Frequency and Code Division Multiplexing
OFDM Orthogonal Frequency Division Multiplexing
OFDMA Orthogonal Frequency Division Multiple Access
10. 10
P/S Parallel-to-Serial ( Converter )
PSD Power Spectral Density
QAM Quadrature Amplitude Modulation
QPSK Quaternary Phase Shift Keying
RF Radio Frequency
Rx Receiver
SC Single Carrier
SNR Signal-to-Noise Ratio
S/P Serial-to-Parallel ( Converter )
SS Spread Spectrum
SS-MC-MA Spread Spectrum Multi-Carrier Multiple Access
TDD Time Division Duplex
TDM Time Division Multiplex
TDMA Time Division Multiple Access
Tx Transmitter
UHF Ultra High Frequency
UL Uplink
WP Wavelet Packet
WP MC Wavelet Packet Based Multi Carrier
11. 11
LIST OF SYMBOLS
A (k) Source Bit of User k
A (k) Source Bit Vector of User k
AP Amplitude of Path p
B (k) Code Bit of User k
B (k) Code Bit Vector of User k
B Bandwidth
Bs Signal Bandwidth
C Speed of Light
C (k) The Spreading Code Vector c(k)
C (k) Spreading Code Vector of User k
Cn Spatial Pre-Coding Vector
C Capacity
C Spreading Code Matrix
D (k) Data Symbol of User k
D (k) Data Symbol Vector of User k
DO Diversity
DF Frequency Diversity
DT Time Diversity
DB Decibel
DBM Decibel Relative to 1 mw
E {.} Expectation
Ebb Energy Per Bit
Ec Energy Per Chip
Es’ Energy Per Symbol
F Frequency
F Carrier Frequency
H Channel Matrix
FD Doppler Frequency
FDf Filter Maximum Doppler Frequency Permitted in the Filter Design
FD max Maximum Doppler Frequency
12. 12
FD p Doppler Frequency of Path p
FN Nth Sub-Carrier Frequency
F Noise Figure in dB/Feedback Information
Fs Sub-Carrier Spacing
Gl l th
Diagonal Element of the Equalizer Matrix G
G Equalizer Matrix
G [j] Equalizer Matrix Used for IC in the jth
Iteration
H (t) Impulse Response of the Receive Filter or Channel Impulse Response
H (τ, t) Time-Variant Channel Impulse Response
H (f, t) Time-Variant Channel Transfer Function
IC Size of the Bit Interleaver
K Number of Active Users
L Spreading Code Length
La Length of the Source Bit Vector a(k)
Lb. Length of the Code Bit Vector b(k)
Ld. Length of the Data Symbol Vector d (k)
M Number of Bits Transmitted Per Modulated Symbol
M Number of Data Symbols Transmitted Per User and OFDM Symbol
n (t) Additive Noise Signal
N Noise Vector
NC Number of Sub-Carriers
Nl 1th
Element of the Noise Vector N
NF Pilot Symbol Distance In Frequency Direction
N Grid Number Of Pilot Symbols Per OFDM Frame
N ISI Number of Interfering Symbols
Ns Number of OFDM Symbols Per OFDM Frame
NT Pilot Symbol Distance in Time Direction
N Tap Number of Filter Taps
P (.) Probability Density Function
P{.} Probability
Pb BER
13. 13
PG Processing Gain
Q Number of User Groups v Received Vector After Inverse OFDM
R (k) Received Vector of the k the User After Inverse OFDM
R Code Rate
Rb Bit Rate
Rect (x) Rectangular Function
R1 Element of the Received Vector
Rs Symbol Rate
S Symbol Vector Before OFDM
S (k) Symbol Vector of User k Before OFDM
SL lst Element of the Vector s
Sinc (x) Sin(x)/x Function
T Time/Number of Error Correction Capability of an RS Code
T Source Symbol Duration
Tc Chip Duration
Td Data Symbol Duration
Tfr OFDM Frame Duration
Tg Duration of Guard Interval
Ts OFDM Symbol Duration without Guard Interval
Ts OFDM Total Symbol Duration with Guard Interval
Tsamp Sampling Rate
U Data Symbol Vector at the Output of the Equalizer
Ul lth
Element of the Equalized Vector u
V Velocity
V Guard Loss in SNR Due to the Guard Interval
V Pilot Loss in SNR Due to the Pilot Symbols
W (k) Soft Decided Value of the Code bit b(k)
W (k) Soft Decided Value of the Code bit Vector b(k)
Wn Power Normalization Factor on Subcarrier n
X (t) Transmitted Signal
14. 14
LIST OF FIGURES
Figure Number Title Page No.
3.1.2 Diagram of Multi Carrier Transmission 19
3.1.2.1 Diagram of Multi Carrier Modulation with Nc = 4 Sub-Channel 20
3.2 Orthogonal Frequency Division Multiplexing Technique 22
3.2.4 Diagram of OFDM- CDM Transmitter and Receiver 23
3.4 Diagram of MC CDMA System 24
3.4.1 Diagram of MC CDMA System 25
3.4.3 Diagram of MC CDMA Transmitter 27
3.4.4 Diagram of MC-CDMA Receiver 28
11.1 Diagram of WP MC-CDMA Transmitter Model 40
11.2 Diagram of Multipath Receiver of Wavelet Packet MC-CDMA 41
Diagram of Binary Phase Shift Keying (BPSK) 54
Diagram of Quadrature Phase Shift Keying (QPSK) 55
15. 15
LIST OF TABLES
Table Number Title Page No.
3.4.2 Different Performance Parameter of MC-CDMA System 26
16. 16
1. ABSTRACT
Conventional Multi-Carrier CDMA (MC-CDMA) technique has become researcher’s hotspots
due to its high frequency spectrum efficiency and high data rate transmission. We propose a
orthogonal wavelet packet based on MC-CDMA system with conventional MC-CDMA
Technique. Wavelet Packet is a MC-CDMA (WP-MC-CDMA) based system and it is superior to
the conventional MC-CDMA with cyclic prefix (CP) in terms of BER using MATLAB and HHT
Tool, Because Hilbert Huang transform is a data and Spectral Analysis Tool. In this application
of space-time coding technique significantly improves the system ability to Channel fading and
various Interferences. Therefore the WP-MC-CDMA system has comparative superiority to MC-
CDMA using HHT tool.
2. INTRODUCTION
Multi-Carrier Code Division Multiple Access (MC-CDMA) is a Multiple access scheme used in
OFDM based telecommunication systems, allowing the system to support multiple users at the
same time. MC-CDMA spreads each user symbol in the frequency domain. That is, each user
symbol is carried over multiple parallel sub carriers, but it is phase shifted (typically 0 or 180
degrees) according to a code value. The code values differ per sub carrier and per user. The
receiver combines all sub carrier signals, by weighing these to compensate varying signal
strengths and undo the code shift. The receiver can separate signals of different users, because
these have different (e.g. orthogonal) code values. Since each data symbol occupies a much
wider bandwidth (in hertz) than the data rate (in bit/s), a signal-to-noise-plus-interference ratio (if
defined as signal power divided by total noise plus interference power in the entire transmission
band) of less than 0 dB is feasible
Space-time coding technique and Multi-carrier CDMA (MC-CDMA) technique have
been research hotspots due to their high frequency spectrum efficiency and high data rata
transmission. On the basis of analyzing the two technique principle, by the use of the optimized
complex orthogonal wavelet packet and space-time coding technique, we propose a complex
orthogonal wavelet packet based MC-CDMA system with space-time coding, and investigate the
system bit error rate performance over Rayleigh fading channel. Theoretical analysis and
simulation results show that the proposed complex wavelet packet based MC-CDMA (CWP-
17. 17
MC-CDMA) system outperforms conventional MC-CDMA system and it is slightly superior to
the conventional MC-CDMA with cyclic prefix (CP). Without any CP, the system has much
higher spectrum efficiency. Especially, the application of space-time coding technique
significantly improves the system ability to combat channel fading and various interference.
Moreover, the space-time coded CWP-MC-CDMA system has comparative superiority to space-
time coded MC-CDMA with CP.
Specialized wavelet packet waveform set, i.e., the waveform generated from a full binary
wavelet packet tree, is used as the modulation waveform in a multicarrier CDMA system. A
novel receiver is designed that utilizes the time domain localization property of the wavelet
packets. In this design multi path signals within one chip period are combined in the time domain
to achieve time–domain diversity in a manner similar to the conventional RAKE receiver design.
Each RAKE finger uses a wavelet packet transform to demodulate the corresponding path of the
multicarrier signal in the time–domain rather than the frequency domain. The demodulated
signal is then depredated using the corresponding spreading code Compared with OFDM or MC-
CDMA, the need of guard intervals in OFDM or MCCDMA is eliminated by using WP time
diversity combining. Compared with Filtered multi tone modulation (FMT) in wireless
application the spectra of each sub carrier in our WP approach are overlapped, resulting in more
efficient use of the spectrum. In other words, the orthogonality of the transmitted waveforms is
achieved not by either cyclic prefix or non overlapping sub channels, but rather by making use of
the unique simultaneous time and frequency localization properties of the WP which are not
achievable by the conventional DFT based OFDM, MC-CDMA, or FMT. This is similar in sprit
to the pulse-shaped to the pulse-shaped OFDM. But our use of a complete set of wavelet
waveforms, instead of only one wavelet
Waveform enables us to exploit explicitly the introduced time-diversity in a RAKE
receiver design. This is different from the sub-space based blind method and different from the
optimum frequency combining. Compared with MC-DS-CDMA, on the other hand, our
approach is practical for truly wideband applications since only on we RAKE receiver is needed
(although one wavelet transform is needed per RAKE finger). In addition, time diversity
combining is in the sub chip level (many samples per chip). The entire frequency band is divided
into a large number of narrow frequency bins, making chip duration much longer than that of
18. 18
MC-DS-CDMA. Therefore, our approach can be regarded as a hybrid between MC-CDMA and
MC-DS-CDMA, but with wavelet packet waveforms replacing the sinusoidal waveforms. The
computational complexity is LWLR times that of MC-CDMA systems for a full wavelet packet
binary tree implementation where, LW is the length of wavelet filters (typically four to eight) LR
is the number of combined RAKE fingers which is still much less than MC-DS-CDMA in
wideband applications.
Hilbert-Huang Transform (HHT) is a data analysis tool, first developed in 1998, which
can be used to extract the periodic components embedded within oscillatory data.
An alternative data analysis tool has been proposed by Norden E. Huang called the Hilbert-
Huang Transform (HHT) [26]. The HHT technique for analyzing data consists of two
components: a decomposition algorithm called empirical mode decomposition (EMD) and a
spectral analysis tool called Hilbert spectral analysis. Both tools will be introduced and described
hereafter. It will be shown that HHT can provide a local description of the oscillating
components of a signal, whether non stationary or nonlinear. This provides a new approach for
analyzing the variability of signals and can be compared with current tools such as any of the
methods mentioned previously.
The Hilbert–Huang transform (HHT), a NASA designated name, was proposed by
Huang et al. (1996, 1998, 1999, 2003, 2012). It is the result of the empirical mode decomposition
(EMD) and the Hilbert spectral analysis (HSA). The HHT uses the EMD method to decompose a
signal into so-called intrinsic mode function, and uses the HSA method to obtain instantaneous
frequency data. The HHT provides a new method of analyzing no stationary and nonlinear time
series data.
3. LITERATURE REVIEW
3.1 Conventional MC CDMA System
3.1.1 Concepts of CDMA
Multiplexing of different data streams can be carried out by multiplying the data symbols of a
data stream with a spreading code exclusively assigned to this data stream before superposition
with the spread data symbols of the other data streams. All data streams use the same bandwidth
at the same time in code division multiplexing. Depending on the application, the spreading
19. 19
codes should as far as possible be orthogonal to each other in order to reduce interference
between different data streams.
Multiple access schemes where the users data are separated by code division multiplexing
are referred to as code division multiple access (CDMA). They are used, for example, in mobile
radio systems, WCDMA/UMTS, HSPA, IS-95, and CDMA-2000.
3.1.2 Multi Carrier Concept
The principle of multi-carrier transmission is to convert a serial high rate data stream On to
multiple parallel low rate sub-streams. Each sub-stream is modulated on another Sub-carrier.
Since the symbol rate on each sub-carrier is much less than the initial serial data symbol rate, the
effects of delay spread, i.e. ISI, significantly decrease, complexity of the equalizer. OFDM is a
low complex technique used to modulate multiple Sub-carriers efficiently by using digital signal
processing.
Orthogonal, n=3
Orthogonal, n=2
Orthogonal, n=1
Non Orthogonal
Orthogonal
Figure 3.1.2 Diagram of Multi Carrier Concept
An example of multi-carrier modulation with four sub-channels NC = 4 is depicted in
Note that the three-dimensional time/frequency/power density representation is used to illustrate
the principle of various multi-carrier and multi-carrier spread spectrum systems .Cuboid
indicates the three-dimensional time/frequency/power density range of the signal, in which most
of the signal energy is located and does not make any statement about the pulse or spectrum
shaping.
(A)
(E)
(D)
(C)
(B)
1cf f 2cf f 3cf f 4cf f 5cf f
1
T
1
T
20. 20
Figure 3.1.2.1 Diagram of Multi-Carrier Modulation with Nc=4 Sub-Channels
An important design goal for a multi-carrier transmission scheme based on OFDM in a
mobile radio channel is that the channel can be considered as time-invariant during one OFDM
symbol and that fading per sub-channel can be considered as flat. Thus, the OFDM symbol
duration should be smaller than the coherence time (t) c of the channel and the sub-carrier
bandwidth should be smaller than the coherence bandwidth (f) c of the channel. By fulfilling
these conditions, the realization of low complex receivers is possible.
– Loss in spectral efficiency due to the guard interval.
– More sensitive to Doppler spreads than single-carrier modulated systems.
– Phase noise caused by the imperfections of the transmitter and receiver oscillators Influences
the system performance.
– Accurate frequency and time synchronization is required.
21. 21
3.2 ORTOGONAL FREQUENCY DIVISION MULTIPLEXING (OFDM)
A communication system with multi-carrier modulation transmits NC complex-valued source
symbols1 Sn, n = 0. . . NC − 1, in parallel on to NC sub-carriers. The source Symbols may, for
instance, be obtained after source and channel coding, interleaving, and Symbol mapping. The
source symbol duration Td of the serial data symbols results after Serial-to-parallel conversion in
the OFDM symbol duration
Ts = Nc Td.
The principle of OFDM is to modulate the NC sub-streams on sub-carriers with a spacing of
Fs = 1/ Ts
In Order to achieve orthogonality between the signals on the NC sub-carriers, presuming a
Rectangular pulse shaping. The Nc parallel modulated source symbols Sn, n = 0. . . NC − 1, Are
referred to as an OFDM symbol.
The NC sub-carrier frequencies are located at
Fn= n/Ts, n= 0. . . Nc − 1.
With 16 sub-carriers versus the normalized frequency fT d is depicted as solid curve in Figure 1-
5.The power density spectrum is shifted to the center frequency. The symbols Sn, n = 0. . . NC −
1, are transmitted with equal power. The dotted curve illustrates the power density spectrum of
the first modulated sub-carrier and indicates the construction of the overall power density
spectrum as the sum of NC individual power density spectra, each shifted by Fs. For large values
of NC, the power density spectrum becomes flatter in the normalized frequency range of −0.5 ≤
fTd ≤ 0.5 containing the NC sub-channels
22. 22
Figure 3.2 Diagram of Ortogonal Frequency Division Multiplexing (OFDM)
3.2.1 Advantages and Drawbacks of OFDM
This section summarizes the strengths and weaknesses of multi-carrier modulation based
on OFDM.
3.2.2 Advantages of OFDM System
High spectral efficiency due to nearly rectangular frequency spectrum for high numbers
Of sub-carriers.
Simple digital realization by using the FFT operation.
Low complex receivers due to the avoidance of ISI and ICI with a sufficiently long
Guard interval.
Flexible spectrum adaptation can be realized, e.g. notch filtering.
Different modulation schemes can be used on individual sub-carriers which are Adapted
to the transmission conditions on each sub-carrier, e.g. water filling.
3.2.3 Disadvantages of OFDM System
Multi-carrier signals with high peak-to-average power ratio (PAPR) require high Linear
amplifiers. Otherwise, performance degradations occur and the out-of-band Power will be
enhanced.
23. 23
3.2.4 OFDM with Code Division Multiplexing ( OFDM-CDM )
OFDM-CDM is a multiplexing scheme that is able to exploit diversity better than conventional
OFDM systems. Each data symbol is spread over several sub-carriers and/or several OFDM
symbols, exploiting additional frequency and/or time diversity By using orthogonal spreading
codes, self-interference between data symbols can be minimized. Nevertheless, self-interference
occurs in fading channels due to a loss of orthogonality between the spreading codes. To reduce
this degradation, efficient data detection and decoding technique is required. The principle of
OFDM-CDM is shown in Figure 3.1
Figure. 3.2.4 Diagram of OFDM with Code Division Multiplexing ( OFDM-CDM )
3.3 POWER CONTROL IN CDMA
CDMA goal is to maximize the number of simultaneous users. Capacity is maximized by
maintaining the signal to interference ratio at the minimum acceptable. Power transmitted by
mobile station must be therefore controlled.
Transmit power enough to achieve target BER No less no more.
3.3.1 TWO FACTORS IMPORTANT FOR POWER CONTROL
Propagation loss
• Due to propagation loss, power variations up to 80 dB.
• A high dynamic range of power control required.
Channel Fading
24. 24
• Average rate of fade is one fade per second per mile. Hour of mobile
speed. Power attenuated by more than 30 dB.
• Power control must track the fade
3.4 DIAGRAM OF MC-CDMA System
The basic MC-CDMA signal is generated by a serial concatenation of classical DSCDMA and
OFDM. Each chip of the direct sequence spread data symbol is mapped on to a different sub-
carrier. Thus, with MC-CDMA the chips of a spread data symbol are transmitted in parallel on
different sub-carriers, in contrast to a serial transmission with DS-CDMA. Let’s assume K be the
number of simultaneously active users1 in an MC-CDMA mobile radio system
Figure 3.4 Diagram of MC-CDMA System
Shows multi-carrier spectrum spreading of one complex-valued data symbol d (k) assigned to
user k. The rate of the serial data symbols is 1/Td .For brevity, but without loss of generality, the
MC-CDMA signal generation is described for a single data Symbol per user as far as possible,
such that the data symbol index can be omitted. In the transmitter, the complex-valued data
symbol d(k) is multiplied with the user specific
Spreading code
c(k) = (c(k) 0 , c(k) 1 , . . . , c(k) L−1)T
L = PG,
25. 25
where PG is the processing gain. The chip rate of the serial spreading code c (k) before serial-to-
parallel conversion .
3.4.1 MC-CDMA SYSTEM
In MC-CDMA systems, high data rate stream is split into a number of parallel low rate streams
and then each sub stream modulates a different sub carrier and is spread over the whole B Width
before transmission .However such a system using large number of Sub carriers is prone to Inter-
Carrier Interference (ICI) problems.
MC-CDMA transmits a data symbol of a user simultaneously on several narrowband sub-
channels. These sub-channels are multiplied by the chips of the user-specific spreading code.
Multi-carrier modulation is realized by using the Low complex OFDM operation. Since the
fading on the narrowband sub-channels can be considered flat, simple equalization with one
complex-valued multiplication per sub channel can be realized. MC-CDMA offers a flexible
system design, since the spreading code length does not have to be chosen equal to the number of
sub-carriers, allowing adjustable receiver complexities.
Figure 3.4.1 Diagram of MC-CDMA System
• It is Frequency domain spreading technique.
• The resulting spectrum of each sub carrier can satisfy the orthogonality condition with
the minimum frequency separation.
• In a (synchronous) down-link mobile radio communication channel, we can use Hada
mard Walsh codes as an optimum orthogonal set.
• It’s a potential candidate for the 4th wireless communication system.
26. 26
3.4.2 MC-CDMA System Parameters
No. Parameter Value characteristics
1 Spreading codes Walsh–Hadamard codes
2 Spreading code length L 8
3 System load Fully loaded
4 Symbol mapping QPSK,8-PSK,16-QAM
5 FEC code rate R and FEC decoder 4/5, 2/3, 1/2, 1/3 with Viterbi decoder
6 FEC codes Convolution codes with memory 6
7 Channel estimation and synchronization Perfect
8 Mobile radio channel Uncorrelated Rayleigh fading channel
Table 3.4.2 MC-CDMA System Parameters
The performance of the MC-CDMA reference system presented in this section is applicable to
any MC-CDMA system with an arbitrary transmission bandwidth B, an arbitrary number of sub-
systems Q, and an arbitrary number of data symbols M transmitted per user in an OFDM symbol,
resulting in an arbitrary number of sub-carriers. The number of sub-carriers within a sub-system
has to be 8, while the amplitudes of the channel fading have to be Rayleigh-distributed and have
to be uncorrelated on the sub-carriers of a sub-system due to appropriate frequency interleaving.
The loss in SNR due to the guard interval is not taken into account in the results. The intention is
that the loss in SNR due to the guard interval can be calculated individually for each specified
guard interval. Therefore, the results presented can be adapted to any guard interval.
3.4.3 MC CDMA TRANSMITTER
An OFDM carrier signal is the sum of a number of orthogonal sub-carriers, with baseband data
on each sub-carrier being independently modulated commonly using some type of quadrature
amplitude modulation (QAM) or phase-shift keying (PSK). This composite baseband signal is
typically used to modulate a main RF carrier.
27. 27
S(n) is a serial stream of binary digits. By inverse multiplexing, these are first de multiplexed
into N parallel streams, and each one mapped to a (possibly complex) symbol stream using some
modulation constellation (QAM, PSK, etc.). Note that the constellations may be different, so
some streams may carry a higher bit-rate than others.
An inverse FFT is computed on each set of symbols, giving a set of complex time-
domain samples. These samples are then quadrature-mixed to pass band in the standard way. The
real and imaginary components are first converted to the analogue domain using digital-to-
analogue converters (DACs); the analogue signals are then used to modulate cosine and sine
waves at the carrier frequency fc, respectively. These signals are then summed to give the
transmission signal,S(t).
Figure 3.4.3 Diagram of MC CDMA Transmitter
3.4.4 MC CDMA RECEIVER
The receiver picks up the signal r(t), which is then quadrature-mixed down to baseband using
cosine and sine waves at the carrier frequency. This also creates signals centered on 2fc, so low-
pass filters are used to reject these. The baseband signals are then sampled and digitized using
analog-to-digital converters (ADCs), and a forward FFT is used to convert back to the frequency
domain.
(a) Transmitter
1cos(2 )f t
2cos(2 )f t
( )MC
j
s t
Copier
1c
2c
t
t
Input Data
Stream
cos(2 )Nf tNc
j
b i
28. 28
This returns N parallel streams, each of which is converted to a binary stream using an
appropriate symbol detector. These streams are then re-combined into a serial stream, s^(n),
which is an estimate of the original binary stream at the transmit
Figure 3.4.4 Diagram of MC CDMA Receiver
4 WALSH–HADA MARD CODES
Orthogonal Walsh–Hada mard codes are simple to generate recursively by using the
following Hada mard matrix generation. The maximum number of available orthogonal
spreading codes is L, which determines the maximum number of active users K. The Hada mard
matrix generation can also be used to perform an L-ray Walsh–Hada mard modulation, which in
combination with PN spreading can be applied in the uplink of an MC-CDMA system
5 AWGN CHANNEL
An AWGN channel is a add white Gaussian noise to the signal that passes through it. Bit error
ratio (BER) is the number of bit errors divided by the total number of transferred bits during a
studied time interval.
BER= Error/ total number of bit
The signal components arriving via different propagation paths may add destructively, resulting
in a phenomenon called signal fading.
(c) Receiver
1cos(2 )f t
2cos(2 )f t
1
j
q
2
j
q
Received
Signal
cos(2 )Nf t
j
Nq
LPF
LPF
LPF
j
D
my
29. 29
6 HILBERT–HUANG TRANSFORM
6.1 Introduction of Hilbert–Huang Transform (HHT)
The Hilbert–Huang transform (HHT) is a way to decompose a signal into so-called intrinsic
mode functions (IMF), and obtain instantaneous frequency data. It is designed to work well for
data that are no stationary and nonlinear. In contrast to other common transforms like the Fourier
transform, the HHT is more like an algorithm (an empirical approach) that can be applied to a
data set, rather than a theoretical tool.
6.2 Introduction to Empirical Mode Decomposition (EMD) and Intrinsic
Mode Functions (IMF)
The fundamental part of the HHT is the empirical mode decomposition (EMD) method. Using
the EMD method, any complicated data set can be decomposed into a finite and often small
number of components, which is a collection of intrinsic mode functions (IMF). An IMF
represents a generally simple oscillatory mode as a counterpart to the simple harmonic function.
By definition, an IMF is any function with the same number of extrema and zero crossings, with
its envelopes being symmetric with respect to zero. The definition of an IMF guarantees a well-
behaved Hilbert transform of the IMF. This decomposition method operating in the time domain
is adaptive and highly efficient. Since the decomposition is based on the local characteristic time
scale of the data, it can be applied to nonlinear and no stationary processes.
6.3 Introduction to Hilbert spectral analysis (HSA)
The Hilbert spectral analysis (HSA) provides a method for examining the IMF's instantaneous
frequency data as functions of time that give sharp identifications of embedded structures. The
final presentation of the results is an energy-frequency-time distribution, designated as the
Hilbert spectrum.
6.4 Hilbert Spectral Analysis ( HSA )
30. 30
Having obtained the intrinsic mode function components, the instantaneous frequency can be
computed using the Hilbert Transform. After performing the Hilbert transform on each IMF
component, the original data can be expressed as the real part, Real, in the following form:
6.5 BIT ERROR RATE (BER) :
The bit error rate or bit error ratio (BER) is the number of bit errors divided by the total number
of transferred bits during a studied time interval. The bit error rate of BPSK in AWGN can be
calculated as BER= Error/ total number of bit .
6.6 MEAN SQUARE ERROR (MSE) :
MSE is a difference between original image and noisy image where, I(i,j) is an original image
and Î(i,j) is an estimate of I(i,j) after Reconstruction.
6.7 PEAK SIGNAL TO NOISE RATIO (PSNR)
PSNR is the ratio between maximum possible pixel of an image and the pixel of corrupting
noise. PSNR is usually expressed in terms of the logarithmic decibel.
7 MC-CDMA SYSTEM
7.1 ADVANTAGES OF MC-CDMA
• Scalability.
• Inter operability in Network and mobile Environment.
• Simple implementation with Hada mard Transform and FFT.
• Low complex receivers.
• High spectral efficiency.
• High frequency diversity gain due to spreading in the frequency.
• Minimum Frequency Separation
31. 31
7.2 DISADVANTAGES of MC-CDMA SYSTEM
• Minimum frequency separation between each sub carrier at the same time.
• Time diversity.
• Detection problem
• Carrier Problem.
• High PAP Respecially in the uplink.
• Synchronous transmission.
7.3 APPLICATIONS OF MC-CDMA
• Beyond 3G and 4G
– High data rates: 100 Mbps for DL 20 Mbps for UL.
– High spectral efficiency in multi-cell environment.
– Open issues:
• slot/frame acquisition channel estimation: MIMO and UL,
• UL synchronization
– Competition with evolution of existing DS-CDMA systems.
• Power Line Communications (PLC)
– Cellular system: resistance to inter-cell interference.
– High data rates (100 Mbps).
– Compliant with authorized spectrum mask.
– Competition with OFDMA.
• Cognitive radio
– Adaptive to unused frequency bands.
• Efficient image transmission.
• Quality evaluation.
• After 3G, Signal can be easily transmitted and received Using FFT Device Without
increasing complexity.
32. 32
8. WAVELET BASED MC CDMA SYSTEM
8.1 Wavelet Based Communication Systems
Wavelets are small waves with finite energy, which have their energy concentrated in time to
give a tool for the analysis of transient, no stationary or time varying functions. A wavelet still
has the oscillating wavelike characteristics, but also has the ability to allow simultaneous time
and frequency analysis with flexible mathematical characteristics. Wavelets are used to analyze
signals in much the same way as complex exponential in Fourier analysis of signals. Wavelet
functions not only can be used to analyze stationary signals (the randomness in the signal does
not change with time, i.e., its mean and variance are independent of time and the autocorrelation
function is a function only of time difference) but it can be used to decompose non stationary and
time varying signals. Wavelets have received considerable attention in signal processing since its
introduction by Daubechies . But, successful migration of the wavelet-based techniques to other
engineering applications has taken some times. Currently, some researchers have begin to exploit
the features of the wavelets that suggest their applications in communication. The basic idea in
the application of wavelets in communications as well as other areas is to represent the signal or
information using wavelet more efficient than with sinusoids.
In this section, the wavelet, wavelet transform, wavelet packets characteristics, wavelet
Packets transform and wavelet packets modulation techniques are reviewed. Then some of
wavelet and wavelet packets applications in communications are discussed.
8.2 Wavelet and Wavelet Transform
Wavelet transform is a two-parameter expansion of a signal in terms of a particular Basis
functions or wavelets. If ψ (t) represent the mother wavelet, then daughter wavelets
are obtained by scaling and translation of ψ(t) as follows.
ψa,b(t) =1/√a ψ(t − b/a)
Where a is the scale or inverse frequency parameter and b is real-valued and called the shift
parameter. The factor 1/√a in the above equation keeps the energy of the daughter wavelets
constant. Each scaled and then translated wavelet keeps the shape of the basic wavelet and has
the same number of oscillation as the basic wavelet. However, the scaling and translation must
33. 33
be applied in appropriate order since they are not commutative. Since {a, b} are continuous-
valued, the ψa,b(t) transform is called Continuous Wavelet Transform(CWT).
8.3 WAVELET PACKET BASED MC CDMA System
Negligible side lobe energy leakage.
Suppressing interference caused by ICI and Multiple Access Interference (MAI).
Naturally orthogonal and well localized in both time and frequency domains.
Relaxes the requirement of frequency or time guard between different user signals.
Orthogonality is maintained for overlapped wavelet packets in both time and frequency
domains.
This is an advantage of using wavelet packets to model communication channels that are
characterized by not only frequency selectivity but also time variation.
8.4 Charactstics of Wavelet Packet
8.4.1 Wavelet Packets and their Characteristics:-
For data compression analysis.
Effect of non-ideal conditions.
Frequency selective channel
The received signal from several paths, carrying the same information, is assumed to be
uncorrelated.
8.4.2 Wavelet and Wavelet Packets Applications in Communications
Since the introduction of wavelet to the signal processing community, it is welcomed as an
alternative to the Fourier transform analysis. This is because it is useful for the analysis and
processing of a class of signals for which a sinusoidal representation is not sufficient. This class
includes no stationary and a transient signal .It is believed that, the wavelet transform is better
than the Fourier transform for the suppression of some type of interferences. The basic idea of
the interference mitigation is to choose a transform such that the interference is transformed to a
delta function in the transform domain, while the desired signal is transformed to a signal that is
34. 34
very flat or orthogonal to the transformed shape of interference. Then, simple exciter can remove
the interference without removing a significant amount of the desired signal energy. An inverse
Transform then can produce the approximately interference free desired signal. Because the
interfering signals are both time and band-limited, the main advantage of using wavelets as
opposed to Short-Time Fourier Transform (STFT) basis functions is the reduction of side lobes
in the transformed domain.
The wavelet transform-based interference mitigation technique is used in DS-Spread
Spectrum (DS-SS) and compares with the Fourier transform interference mitigation techniques.
DWT and STFT isolate a significant amount of stationary narrowband jammer to a relatively
small number of bins. For small number of excised bins, STFT based technique outperforms that
of the DWT. However, with a large number of excised bins, DWT based technique outperforms
that of the STFT. For no stationary interference, the STFT is not capable of isolating the pulsed
interference energy to a small number of bins in transform domain. This is because its nature is
not capable of time resolution. In this case, DWT based technique outperforms that of the STFT
significantly no matter how many bins are excised. Wavelets are also used in channel coding. A
bit-by-bit channel coding technique that uses the orthogonal wavelet coefficient in order to
encode information bits and bi-orthogonal channel coding technique have been proposed. Coding
gains have been obtained in fading channels as well as in bursty noise channels.
Wavelet tends to be smooth functions, since they can overlap in time, and are well
localized in frequency. This in general results in an increase in bandwidth efficiency and a
Reduction in ISI. Hence, wavelet can be used in waveform coding. Due to the orthogonality
properties of wavelets and scaling functions, wavelet has been used for waveform coding of a
composite baseband signals. One signal is coded with the scaling functions and another with the
corresponding wavelets. By this way, wavelets and scaling functions allow these two waveforms
to be transmitted simultaneously as one waveform. This allows two bits to be transmitted during
each bit period resulting in increase in bit rate and bandwidth efficiency.
Besides the above communication applications of wavelet, there is an important area of
application of wavelet in communication as in modulation. Wavelet is used as an orthonormal set
of symbols for signaling and for exploiting multiple access system orthonormality over scale and
time. a class of modulation techniques that relies on orthonormal wavelet families modulating
waveforms are explored.
35. 35
Prior investigations have provided promising results on the usage of wavelet packets in
CDMA communications. the use of wavelet packets as spreading code sequence in CDMA
systems have been proposed.
The basic idea of using wavelet packets in multicarrier CDMA systems has been
proposed and analyzed in several publications. a multicarrier modulation transceiver scheme
based on wavelet packets modulation is designed. The performance of the systems is analyzed in
a slow fading frequency selective Rayleigh channel.
Comparison of the equalization techniques in a wavelet packets based multicarrier DS-
CDMA system is presented. In [38], the performance of a wavelet packets based multicarrier
DS-CDMA system is proposed and analyzed, with the use of multistage interference cancellation
scheme to enhance the system performance. Also, over-sampling is used to achieve better timing
error for path resolution.
In this dissertation two systems based on wavelet packets modulation are proposed
The first system, WP-MC/MCD-CDMA system, combines the multicarrier and multi code
techniques in the design of transceiver scheme based on wavelet packets modulation. This
system can provide multi rate data transmissions by using the multi code techniques. The Second
system, WP-MC/MU-CDMA system, applies the wavelet packets modulation in
The design of multicarrier modulation transceiver scheme. In this system, the
decorrelating Sub optimum detector is used to enhance the system performance. The
performance of the systems is analyzed in a slow fading frequency selective Nakagami channel
and equalization techniques are used to improve the system performance. The systems
performance is investigated in terms of signal-to-noise plus interference-ratio, bit error rate and
outage probability.
9 DETECTION METHODS
In DS-CDMA each user is assigned a distinct signature code to modulate and spread the
information signal and is allowed to transmit through the same channel with other users. The
information signals transmitted by each user can be demodulated by correlating the received
signal with each user’s signature code sequence. The decision can be made based on the
correlator (or matched filter) outputs by employing conventional single user detector technique.
In this section, a brief review of the single user and multiuser detection in DS-CDMA is
36. 36
introduced. For MC-CDMA, MCD-CDMA, MC/MCD-CDMA and WPMC/MCD-CDMA, the
detection is the same. But since the carrier, code, and wavelet packets are used to modulate the
signal at the transmitter, the carrier, code, and wavelet packets are also used to demodulate and
correlate the signal at the receiver
9.1 Conventional Single User Detection
In conventional single user detection, the received signal is demodulated, correlated (or matched
filtered) with the signature code of the reference user, and the detector makes decision by
comparing the correlator outputs to thresholds appropriate for each user’s energy level. Since the
decision for each user’s signal is only based on the output of the correlator that uses the signature
waveform of that users, the detector neglects the interferences or equivalently models the
aggregate noise plus interferences, as noise.
The single user detector is optimum when CDMA signature codes are orthogonal. But, in
practical applications the signature code may not be orthogonal and may exhibit some cross-
correlation properties causing the presences of some degree of interferences. This causes the
receiver to have poor BER performance.
The problem becomes even more severe when the received signal energies are dissimilar.
The detector in this case cannot detect the information transmitted in the weak signals reliably.
This is the well known near-far problem and it is due to the inability of the single user detector to
exploit the structure of other interference. A detector that is robust against this problem is said to
be near-far resistance.
The near-far problem due to MAI is overcome by the implementation of a very fast and
accurate power control. Since power control dictates significant reductions in the transmitted
powers of the strong users in order for weak users to achieve reliable communication, it become
self defeating by decreasing the overall MAI of the system. For an asynchronous system, even
ignoring any near-far problem, the number of users that the single user detector can
accommodate is less than the processing gain. A rule-of-thumb appears to be that a system with
processing gain G can support approximately G/10 users.
37. 37
9.2 Multi user Detection
Multi user detection refers to the detection of mutually interfering signals, which occurs in
various multiple access communication systems. The detection process exploits the information
of all users in the systems, including the interfering users. The suppression of MAI can provide
better performance, support higher number of users and relieve power control requirements.
The optimum detector consisting of a bank of matched filters followed by
Maximum Likelihood Sequence Estimation (MLSE) stage is introduced. In this paper, the
problem of jointly detecting multiple users in a DS-CDMA system with optimal Maximum
Likelihood (ML) detection was analyzed. The basic approach is to perform an exhaustive search
in a centralized ML sequence detector, where the most likely transmitted sequence is found
through maximization of the joint posteriori probability. This can be attained by Viterbi decoding
algorithm, which is essentially a constrained ML approach. The past memory is employed to
determine the most likely values for the currently received symbols from a finite set of possible
symbols. It was found that the poor performance of single user detector was mainly due to
ignoring the information of the other user, not the limitation of the CDMA. The optimum
detector, which is near-far resistance, shows a huge performance and capacity difference
compared with the conventional detector.
However, the optimal detector is computationally complex, which increases
exponentially with the product of the number of users in the system and the channel memory.
This has therefore led to the search for detectors that can decrease the complexity requirements
of multiuser detectors and give near-optimum performance.
In linear detectors, a linear transformation is applied to the soft outputs of the
conventional Detectors in order to get a new set of decision variables, in which MAI is
significantly decoupled. Examples of linear detectors include the linear decorrelating detector
and the Minimum Mean Square Error (MMSE) detector The complexity in these detectors grows
linearly with the number of the users. In the decorrelating detector the interference is nulled out
completely, although noise is enhanced at the same time. The MMSE detector does not
completely remove the interference, but benefits from less noise enhancement at lower SNIR.
In Interference Cancellation (IC) detectors, estimation for the interference is generated
and removed from the received signal before detection. The two types of IC techniques are
Successive (or serial) Interference Cancellation (SIC) and parallel interference cancellation (PIC)
38. 38
.Interference Cancellation detectors are nonlinear and estimates of MAI to be subtracted may be
soft data estimates or hard decision estimates.
The SIC detector performs the decision and cancellation on user-by-user basis starting
from the strongest user. So, it involves ordering of users’ signals according to the received power
level before cancellation. But in PIC, the interference caused by all other users are subtracted
simultaneously from all other signals. When all of the users are received with equal strength, the
PIC outperforms the SIC. But when the received signals are distinctly different in strengths (the
more important case), the SIC is superior in performance.
Many other detectors have been proposed by combining the technique of linear detector
with IC. Decorrelating decision feedback equalizer is one such detector in which decorrelating
detector is combined with successive cancellation. Other combined multiuser detection schemes
are decorrelator/PIC detectors and MMSE/PIC detectors. Decorrelating detector is used to detect
the users signal in the proposed WPMC/MU-CDMA system.
10 PERFORMANCE MEASURES
In communication systems, the goal is to design systems that transmit information to the receiver
with as little deterioration as possible while satisfying design constrains of allowable transmitted
energy, allowable signal bandwidth and cost. In this research, the performance of our proposed
systems is evaluated according to SNIR, BER and outage probability.
Signal-to-Noise plus Interference Ratio
The SNIR is the ratio of signal power to the composite variances of the noise and interference
signals. The channel distorts the signal, noise accumulates along the path and other users,
carriers, codes, and wavelets interfere with the signal as well as with each other. Worse yet, the
signal strength decreases while the noise level increases with distance from transmitter. Also, the
Interference increases with the increase of the number of users, Carriers, codes, and wavelets.
Bit Error Rate
39. 39
Another performance measure commonly use in communication systems is the bit error rate. In
this dissertation, BER of the system is estimated assuming coherent detection. In the presence of
AWGN, the instantaneous probability of error of coherent detection system
11. WAVELET BASED MULTI-CARRIER COMMUNICATION
Wavelet transforms can be thought of as a generalized Fourier Transform while allowing design
of a communication system with certain specific properties. In that respect it is similar to discrete
multiplexing (DMT) and OFDM with certain additional benefits that can be designed by
carefully selecting the orthonormal basis functions.
Discrete Wavelet Packet transform (DWPT) is a variant of Discrete Wavelet transform
(DWT), when decomposition and reconstruction is realized by full tree.
G
1
,G
0
is reconstruction high pass respectively low pass filter and H
1
, H
0
is decomposition
high pass respectively low pass filter. Up arrow and down arrow denote up sampling and down
sampling. Impulse responses of filters are generated from wavelet mother functions (Haar,
Daubechies, Coiflet, Beykin etc.).
Input data stream d is spread with the user specific spreading code c
(k)
with spreading
factor (SF) in the same meaning as above in MC-DS-CDMA. While input to IDWPT (Inverse
DWPT) is a whole matrix S
(k)
Sk= c
(k)
, d
(k)
where c
(k)
is row vector with length SF, d
(k)
is column vector with length Nc.
Circular convolution has been used instead classic convolution.
11.1. TRANSMITTER OF WP-MC-CDMA
Although a number of different schemes are proposed in the literature, the multicarrier CDMA
schemes can be categorized mainly into two groups.
40. 40
First one spreads the original data stream using a given spreading code, and then
modulates a different sub carrier with each chip (the spreading operation in the frequency
domain).
Second spreads the serial-to-parallel (S/P) converted data streams using a given spreading
code, and then modulates a different sub carrier with each of the data stream ( the
spreading operation in the time domain).
Figure 11.1 Diagram of Transmitter of WP-MC-CDMA System
One group spreads the user symbols in the frequency domain and the other spreads user symbols
in the time domain .Wavelet Packets have the property of both time and frequency localization.
Therefore, it is possible to make utilization of this property in two different ways. In this chapter
a wavelet a wavelet Packet based multicarrier CDMA (WP-MC-CDMA) System and time
domain detection algorithm is describe. To achieve time- domain diversity, the signaling of our
proposed system would be similar to that of MC-DS CDMA .this is because such as approach is
more sensitive to the relative time delay and thus multipath signals can be discriminated and then
combined. There is a need of one RAKE combiner for each sub-carrier in an ordinary MC-DS-
CDMA System, the complexity of the receiver depends highly on the number of sub carriers and
limits the number of frequency bins.
11.2. RECEIVER OF WP-MC-CDMA System
Where a series of delayed version of the received signal is detected by single path detectors. In
Each single path detector, a DWPT (Digital Wavelet Packet Transform) block is used for
demodulation of the signal for the corresponding resolved path. The multi-user interference can
41. 41
be effectively eliminated if the desired user spreading code is known, which is assumed true in
the following. The DWPT demodulated signal is forwarded to the dispreading part to obtain a
detected decision variable for the resolved path.
Figure 11.2 Diagram of Multipath receiver of Wavelet Packet MC-CDMA
11.3. WAVELET PACKET BASED DIFFERENT MODULATION
TECHNIQUES
Binary phase shift key.
Q phase shift key.
Hilbert Transform.
Huang Hilbert Transform.
12. COMPARISION BETWEEN CONVENTIONAL MC-CDMA AND
WAVELET PACKET BASED MC-CDMA.
1. WAVELET PACKET BASED MC CDMA SYSTEM
Effect of non-ideal conditions.
Timing and carrier frequency offset.
Synchronization.
Peak-to-average power ratio.
Perfect power control.
42. 42
All received signal from several paths, carrying the same information, are uncorrelated.
2 .MC-CDMA SYSTEM
Receiver employ all the received signal energy.
Combination of CDMA-OFDM to provide multi user capability
Simple receiver structure.
Frequency Diversity avoids deep fades
13. LITERATURE SURVEY
1. Umadevi and K.S. Gurumurthy OFDM Technique for Multi-carrier Modulation
(MCM) Signaling Journal of Emerging Trends in Engineering and Applied Sciences, 2011
OFDM is new multicarrier modulation (MCM) method. It possesses solid benefit of
being a universal communication system and its real features could be extensively modified to
accomplish numerous necessities as well as limitations of an innovative transmission scheme.
Wavelet packet function is assumed as carriers having the features of decent orthogonality as
well as time frequency localization. It is realized from theoretic examination as well as software
experimentation that multi-carrier modulation and demodulation method which is based on
wavelet packet transform possess exclusive benefit in addition to abundant prospective in
refining the performance of scheme. This study shows the process of a WP-MCM system.
Multistage tree-structured par unitary filter banks are used to derive the wavelet packets by
selecting the correct tree organization that will diminish the BER among the anticipated and
obtained signal for a specific channel situation. The experiment for the scheme has been
performed and examined for the AWGN channel. Considering the experimental outcomes, the
authors validate the effectiveness as well as the dynamicity of the suggested wavelet packet
based method. The BER is displayed to be equivalent, sometimes superior, to traditional Fourier
based OFDM. Contrast of dissimilar wavelets was done and out of these Meyer wavelet appears
as the maximum appropriate wavelet via experimental outcomes.
2. Fazel and S. Kaiser Multi-Carrier and Spread Spectrum Systems John Wiley & Sons
Ltd.
The chapters in this book explains MC-CDMA like a frequency PN design whereas MC-
DS-CDMA is explained like a simple modification to DS-CDMA. Authors also debate that the
43. 43
above mentioned matching asymmetric techniques are best appropriate for 4G as the former one
is appropriate in case of downlink. On the other hand, the latter one is considered appropriate for
the uplink in the cellular structures. Though the former technique does superior than the latter
technique, it requires chip management among users. This is the reason for its problematic
deployment in the uplink. Therefore, recognition of multi-carrier spread spectrum procedures is
important for this asymmetric arrangement. Hybrid multiple access systems are explained as
comprehensive schemes. Application questions, comprising synchronization, channel
approximation, as well as RF concerns.
3 Attoush A. H. & Qasaymeh M. M. Design and Simulation of MC-CDMA Transceiver via
Slantlet Transform I.J. Information Technology and Computer Science, 2012
MC-CDMA has appeared lately as a likely contender for the subsequent gen mobile
networks. Lately, it was observed that SLT-OFDM is proficient to lessen the ISI as well as the
ICI. These interferences are produced due to the orthogonality getting lost among the sub-
carriers. SLT based OFDM has the capacity to sustain greater spectrum effectiveness as equated
to FFT-OFDM because of the removal of the CP. In this article, a different SLT-MC-CDMA
transmitter and receiver structure is put forward considering SLT-OFDM as the base. This design
is further used as an elementary building block while designing MC-CDMA’s transmitter and
receiver to preserve the orthogonality keeping in mind the impact of the multi-path frequency
Selective Fading Channels (SFC). Experimental outcomes are given to validate the substantial
improvement of the suggested method. The SLT-MC-CDMA system’s BER is equated with
FFT-MC-CDMA as well as verified in different channels. The experimental consequences
established that, the recommended scheme beats the existing technique.
4. Nathan Yee and Jean-Paul Linnartz Multi-Carrier CDMA in an Indoor Wireless Radio
Channel University of California at Berkeley.
Sighting a swelling rise in demand for private wireless radio communications in the
historical period, technical improvements has seen an increasing necessity to fulfil these
requirements. Upcoming technology should permit managers to effectively share mutual
resources, even if it includes sharing the frequency spectrum, computing services, files, or
storing services. Since for mobile cellular telephony, the reasons after this requirement
44. 44
comprises the mobility as well as dynamicity provided by it. In comparison to wired signal
transmissions, private communication networks would permit operators the association to a
numerous resources though they can relish the liberty of mobility. Indoor wireless
communications is another are of interest that is gaining importance these days. In such an
atmosphere, the usage of a wireless communication linkage eradicates any necessity for electric
wiring. Moreover the elimination of the expenses related with cabling, wireless connections
permit the network to function uninterrupted although fresh operators are entering the network.
5 Heidi Steendam and Marc Moeneclaey Performance of a Flexible Form of MC-CDMA in
a Cellular System Department of Telecommunications and Information Processing,
University of Ghent.
In this article, the authors examine a variation of the old MC-CDMA scheme for
downlink communication. In the suggested scheme, one may autonomously choose the amount
of chips for every symbol (Nchip), the amount of carriers (Ncarr) as well as the FFT length
(NFFT), consequently the existing resources could be made use of efficiently. The dynamic
proposed scheme’s bandwidth is proportionate to Nchip, whereas the power spectrum’s density
is contrariwise proportionate to Nchip: the communicated power is not dependent of Nchip.
Additionally, the power of a small band interferer is spread over an enormous bandwidth by the
dynamic proposed scheme, consequently the resistance of the scheme to such interferers surges
for growing value of Nchip. When there is a dispersive channel present and when the amounts of
users have the value equivalent to Nchip, the powers of the beneficial section, the interference as
well as noise do not depend on the amount of chips per symbol, whereas an optimum guard
period could be established that increases the performance.
6 Dr.Salih M. Salih, M.Sc. Yahya J. Harbi, Talib Mahmoud Ali A Proposed Improvement
Model for MC-CDMA in Selective Fading Channel Anbar Journal of Engineering Sciences
, 2009
In this article, a suggested prototype considering phase matrix rotation was proposed to
increase the performance of MC-CDMA lies in FFT procedure. The evaluation was done
considering the AWGN as well as frequency selective fading channel. To decrease the influence
of multipath fading, this prototype is employed. The outcomes obtained by a computer
45. 45
experiment for a solo user and it equated against the unique method for MC-CDMA relying on
FFT for proposed and existing schemes. As a consequence, it could be understood from the
suggested method that a great performance enhancement was achieved as compared to the
orthodox MC-CDMA, in which the bit error rate is extensively lessened under diverse channel
features for both the channels including frequency selective fading as well as the AWGN
channel.
7 Swati Sharma and Sanjeev Kumar BER Performance Evaluation of FFT-OFDM and
DWT-OFDM International Journal of Network and Mobile Technologies
One of the exceptional method of multi carrier communication is OFDM that is
considered in many applications in various wireless as well as wired methods. In an Orthogonal
Frequency Division Multiplexing system, a huge quantity of orthogonal, intersecting, narrow
band sub-channels, communicated at the same time, distribute the existing communication
bandwidth. The gap between the sun-channels is ideally negligible so that the spectral use is very
compact. This article gives the summary as well as the simulation outcomes of an OFDM
scheme by making use of FFT plus Discrete Wavelet Transform. The outcomes given in the
article are obtained from computer experiments achieved by means of Matlab.
8 P. M. Grant, A. C. McCormick, J. S. Thompson, T. Arslan and A. T. Erdogan
Optimising the Implementation of a FFT-based Multicarrier CDMA receiver EPSRC
Grant No.GR/L/98091
Simulation features of a MC-CDMA receiver having software re-configurable power
depletion is presented. This receiver permits the power depletion to be lessened at the
expenditure of surge in operational delay. This interval might be significant in actual world
response uses for example speech transmissions but for uses for example downloading
information it is not significant. Consequently the power depletion may be improved according
to the application. Power lessening is accomplished by making a trade-off with bigger receiver
latency.
9 Alexandre P. Almeida Member, IEEE , 2Rui Dinis, 3Francisco B. Cercas, Member, IEEE
An FFT-based Acquisition Scheme for DS-CDMA Systems IEEE International
46. 46
Symposium.
This article presents an effective acquirement/association method for DS-CDMA
schemes by making use of a frequency-domain method using TCH- based training blocks. The
traditional time-domain acquirement method is associated with the suggested passive matched-
filter type frequency domain method. Furthermore by means of the point that an N-point DFT
may be divided in M minor DFTs, the authors suggest technique for concurrent decoding/de-
spreading in addition to synchronization which alternates amid 16 bit-length as well as 256 bit-
length recurring ciphers consequently achieving code rate variations.
10 Anil Kumar Dubey, Gourav Vashistha, Parveen reanalysis of BER for wavelet based
mc-cdma communication IJCSMS International Journal of Computer Science &
Management Studies,Vol.11,Issue01,May2011
Since request for greater data rates is unceasingly increasing, there is continuously a
necessity to improve effective wireless methods of communication. The authors established as
well as assessed a multicarrier CDMA wireless scheme of communication based on wavelet
packets. In this scheme a group of wavelet packets are employed the modulation waveforms.
The requirement for CP is eradicated in the scheme owing to the decent orthogonality as well as
time-frequency localization characteristics of the wavelet packets. They possess decent features
for example orthogonality as well as multi rate elasticity, in addition to this, they have given rise
to a numerous works for its uses to code separation.
.
11 LAbib Francis GergisPerformance of MC-MC CDMA Systems With Nonlinear Models
of HPAInternational Journal of Wireless & Mobile Networks (IJWMN) Vol. 3, No. 1,
February2011
A novel wireless system of communication represented as Multi-Code MC-CDMA that is
the amalgamation of Multi -Code and Carrier- CDMA, is examined in this article. This scheme
could fulfill multi-rate facilities by making use of multi-code systems in addition to multi-carrier
facilities which are generally used for higher rate data transmission. The scheme is accessed via
Traveling Wave Tube Amplifier. This kind of amps endure to provide the greatest microwave
amps with greater power in context of power effectiveness, magnitude as well as budget,
however they get behind Solid State Power Amps when it comes to linearity. These articles
47. 47
suggest a method for refining linearity of TWTA. To deliver TWTA performance similar or
greater to orthodox SSPA's, The application of pre-distorter linearization method is defined. The
features of the PD system is obtained from the modification of Saleh's prototype for HPA
12 G.Tomáš KAŠPAREC comparison of wavelet packets in multi- carrier
cdmacommunicationDoctoral Degreee Programme (2) Dept. of Radio Electronics, FEEC,
This paper presents making use of wavelet packet transform as a replacement for Fourier
transform in multi-carrier communiqué. Papers of this arena dedicate typically to Haar or
Daubeschies mother wavelet. In this paper, diverse kinds of mother wavelet are used as well as
equated with flat Rayleigh channel.
13 Xiangbin Yu, Guangguo Bi Performance of Turbo-coded MC-CDMA System Based on
Complex Wavelet Packet in Rayleigh Fading Channel National Mobile Communications
Research Laboratory, Southeast University Nanjing, 210096, China.
In this article, based on examining the norm of MC-CDMA method, by making use of the
improved wavelet packet for modulation of multiple carriers in addition to the turbo codes for
coding the channel, the authors suggest a new MC-CDMA scheme, also examine the scheme
BER in Rayleigh fading channel. The scheme could solve the issue of the reduction of spectrum
effectiveness as well as energy of orthodox system owing to injecting cyclic prefix; and create
proper usage of the better capability of turbo codes under the influence of fading channel to
increase the BER performance. Theoretic examination as well as experimental outcomes
demonstrate that the suggested scheme outclasses orthodox scheme, and it performs greater as
equated to orthodox system with CP. Also, the use of turbo coding toughens the method
capability to manage with multi-path fading as well as multi-access interference considerably.
14 Prof Ali A. A. MIEEE, MCom Soc Department of Electrical Engineering, Isra
University,Amman Jordan Discrete Wavelet Transform Based Wireless Digital
CommunicationSystems. www.intechopen.com
The MC-DS-CDMA scheme’s higher performance via STBC systems as well as DWT is
examined. The assessments of BER for the orthodox MC- DS-CDMA relying on fast Fourier
transform, space time block coding MC-DS-CDMA in addition to discrete wavelet transform
48. 48
based space time block coding MC-DS-CDMA in the diverse prototypes of the channels along
with their assessment for greatest attainable bit error rate have been shown. Experimental
outcomes were given to validate that substantial improvements could be realized by presenting
such amalgamation method having very minute decoding complication. Consequently, the
discrete wavelet transform based space time block coding MC-DS-CDMA is a practicable
method to achieve the subsequent generation of wireless communiqué for great data rates as well
as uses.
15 Abbas Kattoush A Novel Radon-Wavelet-Based Multi-Carrier Code Division Multiple
Access Transceiver Design and Simulation under Different Channel Conditions The
International Arab Journal of Information Technology, Vol. 9, No. 3, May 2012
It was established lately that Radon-DWT based OFDM is proficient of decreasing the
ISI as well as the ICI that is triggered by the damage of orthogonality among the signal carriers.
Radon-DWT-OFDM could correspondingly provide considerably advanced spectrum
effectiveness as compared to FFT- OFDM. In this article a new Radon-DWT-MC-CDMA
transmitter and receiver strategy is offered that is considered as an elementary element in the
design of transceiver. It is done such that orthogonality of the signals can be increased against
the multi-path frequency selective fading channels. Experimental outcomes are delivered to
validate the substantial improvements in performance as well as easiness owing to the suggested
method. The BER of the suggested system was equated to MC-CDMA based on FFT, MC-
CDMA based on Radon, as well as DMWT based CDMA. These were verified in AWGN, Flat
fading in addition to Selective fading channels. The experimental outcomes exhibited that
suggested scheme outclasses the other schemes.
16 Md. Matiqul Islam, M. HasnatKabir and Sk. EnayetUllah Performance Analysis of
Wavelet Based MC-CDMA System with Implementation of Various Antenna Diversity
Schemes International Journal of Research and Reviews in Computer Science (IJRRCS)
The effect of making use of method relying on wavelet on the performance of a MC-
CDMA scheme has been examined. The scheme in suggested paper includes Walsh Hadamard
codes to distinguish the communication signal for separate operator. A computer software
package inscribed in Mathlab code is created. This experimental work is done with application of
49. 49
numerous antenna diversity systems as well as fading channels. Experimental outcomes validate
that the suggested scheme outclasses in Alamouti under AWGN and Rician channel.
17 Mohamed N. El-Eskandrani, Ehab F. Badran and Darwish A. Mohamed Investigation
of the Performance of the Wavelet Packet Based Multi-Carrier CDMA Communications in
Rayleigh Fading Channel Arab Academy for Science and Technology and Maritime
Transport,Alexandria.
In this article, an examination of the wavelet transform’s performance as well as
performance of MC-CDMA communications based on wavelet packet in Rayleigh fading
channel was offered for diverse wavelet classes. Wavelets packets that are orthonormal were
substituted for complex exponential carriers of MC-CDMA which are based on Fourier. The
BER of the wavelet transform as well as wavelet packet based MC-CDMA in Rayleigh fading
channel and AWGN Channels are equated. Correspondingly, the outcomes are analyzed against
FFT based MC-CDMA’s performance under impact of Rayleigh fading channel.
14. RATIONALE
The Old-style MC-CDMA based on Fourier transform has presently seeking maximum of focus
in the region of wireless communication. To battle ISI as well as ICI, CP is injected among MC-
CDMA ciphers that consume nearby 25 % of bandwidth, We are suggesting MC-CDMA based
on Wavelet packet with the intention of improving bandwidth effectiveness (spectral
effectiveness) in addition to reducing the amount of interference.
15. PROBLEM STATEMENT
“Comparison Analysis of Wavelet Packet Based MC CDMA and Conventional MC-CDMA
Technique Using HHT Tool.”
16. METHODOLOGY
Simulation of CDMA Technology with fading channel.
Simulation of MIMO OFDM in mat lab.
Simulation of MC CDMA.
50. 50
Wavelet packet based MC CDMA.
Simulation for the same various modulation techniques.
Comparison of wavelet packet CDMA for various wavelet functions.
Power spectrum of MC CDMA.
This research is divided into three phases.
The initial phase involves designing the simulation model to be used for obtaining
data. The simulation will mimic a given communication system and its process. Once
developed, the algorithm will be applied to the given scenario and then simulated in
order to analyze the proposed methods.
The second phase consists of developing the specifics of the algorithm. This involves
devising the logic details as well as the details pertaining to the comm. network. This
phase is the focus of the study and therefore requires the most detail and explanation.
Finally, the proposed method will be analyzed and compared to a current method. The
comparison will involve the simulation model being applied to an multiplexing
Technique. The complete methodology will be described in detail in result section.
17. EXPECTED OUTCOMES
The SNIR performance for WP-MC CDMA system.
Effect of Mean Energy-to-Noise Power Spectral Density.
Number of Wavelet Packets Super streams.
Bit Error Rate Performance comparison.
18. CONCLUSION
In conclusion, the proposed wavelet packet based multicarrier CDMA system and
detection algorithm have the ability to distinguish and combine multipath signals within chip
duration due to the time localization property of the wavelet packets. This ability eliminates the
need for the guard interval between consecutive symbols. We presented here the system designs
for wavelet packet based multicarrier CDMA communications. In this system design a set of
wavelet packets are used as the modulation waveforms in a multicarrier CDMA system. The
51. 51
need for cyclic prefix is eliminated in the system design due to the good orthogonality and time-
frequency localization
• BER (Bit Error Rate)
• RMSE (Root Mean Square Error)
• PSNR (Peak Signal To Noise Ratio)
19. PROGRESS SO FAR
We studied about the problem statement and find out what actually we have to do also we find
the tool on which we are doing work presently.
And we have the coding of MC CDMA is completed .and simulation of MC CDMA in
METLAB is also done in the phase 1.
And we proceed the WP MC CDMA is design and simulate in using METLAB. and
compare both the technique.
52. 52
GLOSSARY & KEYWORDS
Hilbert–Huang Transforms (HHT) : 1.The name of Hilbert–Huang transforms (HHT) was
designated by NASA and it was recommended by Huang et al. (1996, 1998, 1999, 2003, 2012).
It is the outcome of the empirical mode decomposition (EMD) and the Hilbert spectral analysis
(HSA). The decomposition of the signal in IMF is done by using the EMD technique and
immediate data related to frequency can be obtained by the HAS method. The HHT delivers a
novel technique of examining no stationary and non-linear time series data.
2.Hilbert–Huang Transform (HHT) is a way to decompose a signal into so-called intrinsic
mode functions (IMF), and obtain instantaneous frequency data. It is designed to work well for
data that are no stationary and nonlinear. In contrast to other common transforms like the Fourier
transform, the HHT is more like an algorithm (an empirical approach) that can be applied to a
data set, rather than a theoretical tool.
HHT Based MC-CDMA : A signal could be disintegrated into intrinsic mode functions (IMF)
by means of Hilbert–Huang transform (HHT) which can also be used to obtain immediate
frequency information. It is intended to do fine for information that is non-stationary as well as
non-linear. This transform is identical to a procedure (an experimental method) when compared
to other basic transforms for example, the Fourier transform. Furthermore it could be applied to a
data set too.
Orthogonal Frequency Division Multiplexing (OFDM) : The OFDM can be considered as a
multi-carrier modulation technique that is extensively accepted as well as maximum frequently
used now-a-days. In this, the modulation as well as demodulation is realized effortlessly by
Inverse DFT and DFT operators.
OFDM with Code Division Multiplexing (OFDM-CDM) : OFDM with Code Division
Multiplexing is a multiplexing system which is capable to use diversity in a superior way as
compared to traditional Orthogonal Frequency Division Multiplexing systems. For dissemination
of all the data symbols, numerous sub-carriers and/or numerous OFDM symbols are used. This is
how the system exploits extra time and/or frequency diversity.
Bit Error Rate (BER) : 1.This is the quantity of bit errors divided by the entire quantity of
transmitted bits through a considered time period. The BER of Binary Phase Shift Keying in
Additive White Gaussian Noise might be computed as BER= Error/ total number of bit .
53. 53
2.The bit error rate or bit error ratio (BER) is the number of bit errors divided by the total
number of transferred bits during a studied time interval. The bit error rate of BPSK in AWGN
can be calculated as BER= Error/ total number of bit .
Peak Signal To Noise Ratio (PSNR) : PSNR is the ratio between maximum possible pixel of
an image and the pixel of corrupting noise. PSNR is usually expressed in terms of the
logarithmic decibel.
Mean Square Error (MSE) : MSE is a difference between original image and noisy image
where, I(i,j) is an original image and Î(i,j) is an estimate of I(i,j) after Reconstruction.
Multiple Access Interference (MAI) : MC-CDMA system’s performance declines quickly with
the surge in amount of instantaneously active users because the capability of system having
modest processing gain is restricted by MAI.
Empirical Mode Decomposition (EMD) and Intrinsic Mode Functions (IMF) : The
fundamental part of the HHT is the empirical mode decomposition (EMD) method. Using the
EMD method, any complicated data set can be decomposed into a finite and often small number
of components, which is a collection of intrinsic mode functions (IMF). An IMF represents a
generally simple oscillatory mode as a counterpart to the simple harmonic function. By
definition, an IMF is any function with the same number of extrema and zero crossings, with its
envelopes being symmetric with respect to zero. The definition of an IMF guarantees a well-
behaved Hilbert transform of the IMF. This decomposition method operating in the time domain
is adaptive and highly efficient. Since the decomposition is based on the local characteristic time
scale of the data, it can be applied to nonlinear and no stationary processes.
Hilbert Spectral Analysis (HSA) : Having obtained the intrinsic mode function components,
the instantaneous frequency can be computed using the Hilbert Transform. After performing the
Hilbert transform on each IMF component, the original data can be expressed as the real part,
Real, in the following form:
The instant frequency could be calculated by making use of the Hilbert Transform once the
components of the IMF have been obtained. The primary data could be stated as the real part
after executing the transform on every IMF constituent in the subsequent system.
54. 54
Hilbert Spectral Analysis (HSA) : 1.The Hilbert spectral analysis (HSA) offers a technique for
investigating the Intrinsic Mode Function’s immediate data related to frequency as functions of
time which provides sharp IDs of embedded structures. The final outcome is an energy-
frequency-time spread that can be labeled as the Hilbert spectrum.
2.The Hilbert spectral analysis (HSA) provides a method for examining the IMF's instantaneous
frequency data as functions of time that give sharp identifications of embedded structures. The
final presentation of the results is an energy-frequency-time distribution, designated as the
Hilbert spectrum.
Additive White Gaussian Noise (AWGN) Channel : An AWGN channel is defined as additive
white Gaussian noise to the signal that goes through it. The components of signal incoming
through dissimilar propagation routes might add in a destructive way, leading to a phenomenon
known as signal fading.
Binary Phase Shift Keying (BPSK) : The most straightforward type of PSK is called binary
phase shift keying (BPSK), where ―binary‖ refers to the use of two phase offsets (one for logic
high, one for logic low).
We can intuitively recognize that the system will be more robust if there is greater separation
between these two phases—of course it would be difficult for a receiver to distinguish between a
symbol with a phase offset of 90° and a symbol with a phase offset of 91°. We only have 360° of
phase to work with, so the maximum difference between the logic-high and logic-low phases is
180°. But we know that shifting a sinusoid by 180° is the same as inverting it; thus, we can think
of BPSK as simply inverting the carrier in response to one logic state and leaving it alone in
response to the other logic state.
To take this a step further, we know that multiplying a sinusoid by negative one is the same as
inverting it. This leads to the possibility of implementing BPSK using the following basic
hardware configuration:
Diagram of Binary Phase Shift Keying (BPSK)
55. 55
Quadrature Phase Shift Keying (QPSK) : BPSK transfers one bit per symbol, which is what
we’re accustomed to so far. Everything we’ve discussed with regard to digital modulation has
assumed that the carrier signal is modified according to whether a digital voltage is logic low or
logic high, and the receiver constructs digital data by interpreting each symbol as either a 0 or a1.
Before we discuss quadrature phase shift keying (QPSK), we need to introduce the following
important concept: There is no reason why one symbol can transfer only one bit. It’s true that the
world of digital electronics is built around circuitry in which the voltage is at one extreme or the
other, such that the voltage always represents one digital bit. But RF is not digital; rather, we’re
using analog waveforms to transfer digital data, and it is perfectly acceptable to design a system
in which the analog waveforms are encoded and interpreted in a way that allows one symbol to
represent two (or more) bits.
QPSK is a modulation scheme that allows one symbol to transfer two bits of data. There are four
possible two-bit numbers (00, 01, 10, 11), and consequently we need four phase offsets. Again,
we want maximum separation between the phase options, which in this case is 90°.
Diagram of Quadrature Phase Shift Keying (QPSK)
56. 56
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[3] Anil Kumar Dubey, Gourav Vashistha, Praveen reanalysis of BER for wavelet based
MC-CDMA communication.
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Access Transceiver Design and Simulation under Different Channel Conditions The
International Arab Journal of Information Technology, Vol. 9, No. 3, May 2012.
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An FFT-based Acquisition Scheme for DS-CDMA Systems ,IEEE International
Symposium on Information Theory.
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using interference cancellation,‖ IEEE 5th Int. Symp. On Spread Spectrum Techniques
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in a Cellular System department of Telecommunications and Information Processing,
University of Ghent.
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[12] H.Tao, N. Arum gam, and G. H. Krishna, ―Performance of space-time coded MC-CDMA
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[21]. P. M. Grant, A. C. McCormick, J. S. Thompson, T. Arslan and A. T. Erdogan Optimizing
the Implementation of a FFT-based Multicarrier CDMA receiver EPSRC Grant No. Gr /
L / 98091.
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CDMAModulation, Maters Degree Thesis, The University of Akron, May 2003.
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Model for MC-CDMA in Selective Fading Channel Anbar Journal of Engineering
Sciences , 2009.
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DWT-OFDM International Journal of Network and Mobile Technologies
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―Wavelet Packet Modulation for Multicarrier CDMA ―Communications‖24th National
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Complex Wavelet Packet in Rayleigh Fading Channel National Mobile Communications
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Wireless Telecomm. Summit (IST), Aveiro, Portugal, June 15–18, 2004.
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60. 60
LIST OF PUBLICATION
1 Manmohan Singh Chandoliya and Ms.Anila Dingra ― Comparative Analysis Of Wavelet
Packet Based MC-CDMA With The Conventional MC-CDMA System Using Huang
Hilbert Transform‖ ISRJ (IMRJ) - Indian Streams Research Journal ( International
Multidisciplinary Research Journal ), Volume 4, Issue 12, ISSN ( online ): 2230-7850,
January 2015.
2 Manmohan Singh Chandoliya and Ms.Anila Dingra ― Comparative Analysis of Wavelet
Packet Based MC-CDMA With The Conventional MC-CDMA System Using Huang
Hilbert Transform” IJR PARIPEX - Indian Journal of Research PARIPEX, Volume 4,
Issue 4, ISSN ( online ): 2250-1991, April 2015.
3 Manmohan Singh Chandoliya and Ms.Anila Dingra ― Performance Analysis Of Wavelet
Packet Based MC-CDMA With The MC-CDMA System Using HHT Transform With
Different No of User‖ IJARSE - International Journal of Advanced Research in Science
and Engineering, Volume 4, Issue 5, ISSN ( online ): 2319-8354(E), May 2015.
4 Manmohan Singh Chandoliya ― Comparative Analysis Of MC-CDMA System with
Wavelet Packet Based MC-CDMA System Using Different Modulation Techniques‖
IOSR-JEEE – International Organization of Scientific Research- Journal of Electrical
and Electronics Engineering, Volume 9, Issue 3, Version 5, ISSN ( online ): 2320-3331,
May-Jun 2014.
5 Manmohan Singh Chandoliya ― Analysis Of Wavelet Packet Based MC-CDMA With
The MC-CDMA System Using HHT Transform With BER and User‖ IJIREEICE -
International Journal of Innovative Research in Electrical, Electronics, Instrumentation
and Control Engineering, Volume 3, Issue 6, ISSN ( online ): 2321-2004, June 2015.
6 Manmohan Singh Chandoliya ― Multi-Microcontroller Communication for Control
Industrial Application‖ ISRJ (IMRJ) - Indian Streams Research Journal ( International
Multidisciplinary Research Journal ), Volume 5, Issue 4, ISSN ( online ): 2230-7850,
May 2015.
7 Manmohan Singh Chandoliya ― Multi-Microcontroller Communication Using Control
Industrial Application‖ IJPAR - International Journal of Pure and Applied Researches,
Volume 1, Issue 1, ISSN ( online ): 2320-2831, 2015.
61. 61
8 Manmohan Singh Chandoliya ― Control Industrial Application Using Multi-
Microcontroller Communication‖ IJIREEICE - International Journal of Innovative
Research in Electrical, Electronics, Instrumentation and Control Engineering, Volume 3,
Issue 7, ISSN ( online ): 2321-2004, July 2015.
9 Manmohan Singh Chandoliya ―Multi-Microcontroller Communication Using Control
Industrial Application‖ NAIRJSEIT - North Asian International Research Journal of
Science, Engineering and Information Technology, Volume 1, Issue 5, ISSN ( online ):
2454-7514, December 2015.
62. 62
APPENDIX
The aim of this work is to investigate the performance of multi-carrier code division
multiple access (MC-CDMA) technique, which is a key technology for efficient and reliable
communication due to its high frequency spectrum efficiency and high data rate transmission. As
demand for higher data rates is continuously rising, there is always a need to develop more
efficient wireless communication systems. For this purpose, the MC-CDMA technology, which
is the combination of both orthogonal frequency division multiplexing (OFDM) and CDMA, is
considered to increase the potential benefits of the communication system.
In this thesis, we investigate the performance of conventional MC-CDMA system,
orthogonal wavelet packet based MC-CDMA system (WP-MC-CDMA), and Huang Hilbert
Transformation (HHT) based MC-CDMA system. Although, conventional MC-CDMA has
already been discussed in the literature, and used as a benchmark for other two schemes. In
addition, in the orthogonal wavelet packet based MC-CDMA system, we design a set of wavelet
packets and used as the modulation waveforms in a multicarrier CDMA system. The WP-MC-
CDMA shows their superiority over conventional MC-CDMA in terms of bit error rate (BER),
and helps to mitigate the effects of interference and channel fading. Moreover, we also
investigate the performance of Huang Hilbert Transformation based MC-CDMA. This scheme
outperforms other two techniques, because this scheme is based on the knowledge of the
instantaneous channel state information, or based on instantaneous imperfect channel estimates.
Thus, by the knowledge of their channel gains or channel information, it can analyze the data
more accurately. Hence, it is a more spectral efficient and high data rate transmission scheme
compared to the conventional MC-CDMA and WP-MC-CDMA. Furthermore, a comparison is
also made among all three schemes in terms of BER, Throughput and different modulation
techniques. Numerical and simulation results are presented to validate our proposed schemes.
Simulation Steps
Step 1: The initial phase involves review of various literatures on its basis of given MC-CDMA
and WP based MC-CDMA communication system and its process.
Step 2: The second phase consists of design the conventional MC-CDMA system and WP-MC-
CDMA system and HHT-MC-CDMA system. We have used following steps:
Simulation of CDMA technology with fading channel.
Simulation of conventional MC-CDMA system using MATLAB.
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Simulation of WP-MC-CDMA system.
Simulation for the different modulation methods like (BPSK, QPSK)
modulation technique.
Simulation of HHT based MC-CDMA system.
Comparative study of HHT-MC-CDMA system, WP-MC-CDMA system with
the traditional MC-CDMA system using BER and different number of users.
Step 3: Finally, the proposed method will be analyzed and compared to current methods. The
comparison will involve different parameters like BER and different number of user. The
complete methodology will be described in detail in result section.
Step 4: BER vs SNR for Conventional MC-CDMA for different users.
Step 5: BER vs SNR for Wavelet packet based MC-CDMA for dissimilar users
Step 6: BER vs SNR for HHT based MC-CDMA For Dissimilar Users
Step 7: BER vs SNR Assessment of three systems for k=1
Step 8: BER vs SNR comparisons of three System When k=2
Step 9: Performance analysis of BER using BPSK Method in MC-CDMA
Step 10: Performance analysis of BER using QPSK Technique in MC-CDMA
Step 11: Performance Analysis of BER using QAM8 Method in MC-CDMA
Step 12: Comparison Analysis of MC-CDMA using BPSK, QAM8 Modulation Techniques
Step 13: Comparative Analysis of WP MC - CDMA System using BPSK, QPSK Techniques
Step 14: Conclusion
In this thesis, the traditional MC-CDMA scheme WP-MC-CDMA as well as MC-CDMA
system based on HHT has been analyzed. In precise, we investigated how orthogonal WP based
scheme performs by scheming a group of wavelet packets. These wavelet packets were assumed
as the modulation waveforms in a MC-CDMA system. Furthermore, we examined HHT based
system. Arithmetical as well as experimental consequences demonstrate that the HHT based
System, outperforms other two in context of BER, and supports to alleviate the impact of
nosiness and channel diminishing. The upgraded performance of wavelet based system by
making use of HHT based MC-CDMA system is examined. The evaluations of BER
performance for the traditional system based on FFT, wavelet based system and HHT based
system in the diverse channel prototypes along with their evaluation for greatest realizable bit
error rate have been shown.
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Experimental outcomes were given to validate that substantial throughput, BER and
different modulation techniques like BPSK, QPSK and M Ray QAM might be realized by
presenting such grouping method having very less decoding difficulty. Consequently, the WT
based system is a practical method to reach the succeeding advancements in wireless
transmission sin tended for great information rates as well as uses. In this thesis, HHT Based
MC-CDMASystem is also evaluated. In this Paper, the diverse models of the grouping of
multiple-carrier communication with spread spectrum, specifically MC-CDMA and system
based on wavelets, as well as HHT based MC-CDMA system are comprehensively evaluated and
investigated, numerous solo-user as well as multiple-user recognition approaches and their
performance in context of bit error rate and spectral effectiveness are observed.
Step 15: MATLAB Programme
% HADAMARD MATRIX GENERATION
clc;
n=input('enter order of square hadamard matrix');
m=[];
for i=1:n
m(1,i)=-1;
end
for i=2:n
for j=1:n/2
m(i,j)=-1;
end
end
for i=2:n
for j=((n/2)+1):n
m(i,j)=1;
end
end
m
m2=[];
m2=[m m;
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m -m];
m2
% MC-CDMA USING HADAMARD CODE FOR 4 USERS%
clc ;
d = randn(1,4*100000) ;
c=1;
for o = 1:4
for j = 1:100000
if ( d(c)>=0)
D1(o,j)=1 ;
else
D1(o,j)=-1 ;
end
c = c+1 ;
end
end
for o = 1:4
j=1;
for k = 1:50000
D(o,k)=D1(o,j)+(D1(o,j+1))*1i;
j=j+2;
end
end
C=[-1 -1 -1 -1;
-1 1 -1 1;
-1 -1 1 1;
-1 1 1 -1];
M = length(C);
M