The document compares the performance of single stage and double stage interleavers in communication systems using turbo codes. A single stage interleaver uses one random interleaver between two convolutional encoders, while a double stage interleaver uses two interleavers in series. The document suggests that a double stage interleaver can improve the bit error rate (BER) of the system compared to a single stage interleaver by further scrambling the input bits. It also provides details on the components of a turbo code system such as convolutional encoders, interleavers, puncturing, and iterative decoding.
IJERD (www.ijerd.com) International Journal of Engineering Research and Devel...IJERD Editor
This document summarizes a study on the performance of turbo coded orthogonal frequency division multiplexing (OFDM) over fading channels. It describes how OFDM can mitigate inter-symbol interference caused by frequency selective fading channels by dividing the channel into parallel subchannels. It then provides details on turbo coding, including the encoder and iterative decoder design. The system model studied transmits a turbo coded OFDM signal over a frequency selective Rayleigh fading channel and evaluates the performance for rate 1/3 and 1/2 turbo codes. Simulation results are presented to analyze the bit error rate.
Comparative evaluation of bit error rate for different ofdm subcarriers in ra...ijmnct
In the present situation, the expectation about the quality of signals in wireless communication is as high as possible. This quality issue is dependent upon the different communication parameters. One of the most important issues is to reduce the bit error rate (BER) to enhance the performance of the system. This paper provides a comparative analysis on the basis of this bit error rate. I have compared the BER for different number of subcarriers in OFDM system for BPSK modulation scheme. I have taken 6 varieties of data subcarriers to analyze this comparison. Here my target is to reach at the lowest level of BER for BPSK modulation. That is achieved at 2048 number of subcarriers.
CDMA Transmitter and Receiver Implementation Using FPGAIOSR Journals
Abstract: Code Division Multiple Access (CDMA) is a spread spectrum technique that uses neither frequency channels nor time slots. With CDMA, the narrow band message (typically digitized voice data) is multiplied by a large bandwidth signal that is a pseudo random noise code (PN code). All users in a CDMA system use the same frequency band and transmit simultaneously. The transmitted signal is recovered by correlating the received signal with the PN code used by the transmitter. The DS - CDMA is expected to be the major medium access technology in the future mobile systems owing to its potential capacity enhancement and the robustness against noise. The CDMA is uniquely featured by its spectrum-spreading randomization process employing a pseudo-noise (PN) sequence, thus is often called the spread spectrum multiple access (SSMA). As different CDMA users take different PN sequences, each CDMA receiver can discriminate and detect its own signal, by regarding the signals transmitted by other users as noise- like interferences. In this project direct sequence principle based CDMA transmitter and receiver is implemented in VHDL for FPGA. Modelsim 6.2(MXE) tool will be used for functional and logic verification at each block. The Xilinx synthesis technology (XST) of Xilinx ISE 9.2i tool will be used for synthesis of transmitter and receiver on FPGA Spartan 3E. Keywords: CDMA, DSSS, BPSK, GOLD code.
Performance of OFDM System under Different Fading Channels and Channel CodingjournalBEEI
Orthogonal frequency division multiplexing (OFDM) is a type of multicarrier modulation (MCM) technique in which larger bandwidth is divided into parallel narrow bands each of which is modulated by different subcarriers. All the subcarriers are orthogonal to each other and hence it reduces the interference among various subcarriers. OFDM technique is an efficient modulation technique used in certain wired and wireless application.In a wireless communication channel, the transmitted signal can travel from transmitter to receiver over multiple reflective paths. This results to multipath fading which causes fluctuations in amplitude, phase and angle of arrival of the received signal. For example, the signal which is transmitted from BTS (base transceiver station) may suffer multiple reflections from the buildings nearby, before reaching the mobile station. Such multipath fading channels are classified into slow fading/fast fading and frequency-selective/flat fading channels. This paper discusses the performance of OFDM system using various fading channels and channel coding. The parameter which is known as Bit error rate (BER) is calculated under different fading channels (AWGN, Rayleigh and Rician) for different digital modulation (BPSK, QPSK and QAM) and Channel coding (linear/Cyclic coding). Matlab Simulink tool is used to calculate the BER parameter.
Pmit lecture 03_wlan_wireless_network_2016Chyon Ju
The document discusses requirements and specifications for wireless local area networks (WLANs). It notes that the IEEE 802 committee develops standards for wired and wireless networking, including 802.11 for WLANs. The document then describes several 802.11 specifications such as 802.11, 802.11a, 802.11b, and 802.11g that define transmission speeds and frequencies for WLANs. It also discusses modulation techniques like BPSK and QPSK used in wireless communications.
This document provides an analysis of different pseudorandom and orthogonal spreading sequences used in direct sequence code division multiple access (DS-CDMA). It begins with an introduction to CDMA transmission and reception and an example of direct sequence spread spectrum. It then discusses various pseudorandom sequences like maximal length sequences, Gold sequences, Gold-like sequences, Barker sequences, and Kasami sequences. It also covers orthogonal sequences including Walsh-Hadamard codes, modified Walsh-Hadamard codes, and orthogonal variable spreading factor codes. The document concludes by comparing the performance of these different sequences based on their correlation properties and suitability for use in CDMA networks.
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.
Chapter 6 - Digital Data Communication Techniques 9eadpeer
Digital data communication techniques use asynchronous or synchronous transmission. Asynchronous transmission sends data one character at a time, while synchronous transmission sends data in blocks without start/stop codes. Error detection codes like parity and CRC are added to detect errors, while error correction codes can correct errors by adding redundancy. Line configurations consider topology (star, bus, etc.) and duplex mode (half duplex uses one path while full duplex uses two simultaneous paths).
IJERD (www.ijerd.com) International Journal of Engineering Research and Devel...IJERD Editor
This document summarizes a study on the performance of turbo coded orthogonal frequency division multiplexing (OFDM) over fading channels. It describes how OFDM can mitigate inter-symbol interference caused by frequency selective fading channels by dividing the channel into parallel subchannels. It then provides details on turbo coding, including the encoder and iterative decoder design. The system model studied transmits a turbo coded OFDM signal over a frequency selective Rayleigh fading channel and evaluates the performance for rate 1/3 and 1/2 turbo codes. Simulation results are presented to analyze the bit error rate.
Comparative evaluation of bit error rate for different ofdm subcarriers in ra...ijmnct
In the present situation, the expectation about the quality of signals in wireless communication is as high as possible. This quality issue is dependent upon the different communication parameters. One of the most important issues is to reduce the bit error rate (BER) to enhance the performance of the system. This paper provides a comparative analysis on the basis of this bit error rate. I have compared the BER for different number of subcarriers in OFDM system for BPSK modulation scheme. I have taken 6 varieties of data subcarriers to analyze this comparison. Here my target is to reach at the lowest level of BER for BPSK modulation. That is achieved at 2048 number of subcarriers.
CDMA Transmitter and Receiver Implementation Using FPGAIOSR Journals
Abstract: Code Division Multiple Access (CDMA) is a spread spectrum technique that uses neither frequency channels nor time slots. With CDMA, the narrow band message (typically digitized voice data) is multiplied by a large bandwidth signal that is a pseudo random noise code (PN code). All users in a CDMA system use the same frequency band and transmit simultaneously. The transmitted signal is recovered by correlating the received signal with the PN code used by the transmitter. The DS - CDMA is expected to be the major medium access technology in the future mobile systems owing to its potential capacity enhancement and the robustness against noise. The CDMA is uniquely featured by its spectrum-spreading randomization process employing a pseudo-noise (PN) sequence, thus is often called the spread spectrum multiple access (SSMA). As different CDMA users take different PN sequences, each CDMA receiver can discriminate and detect its own signal, by regarding the signals transmitted by other users as noise- like interferences. In this project direct sequence principle based CDMA transmitter and receiver is implemented in VHDL for FPGA. Modelsim 6.2(MXE) tool will be used for functional and logic verification at each block. The Xilinx synthesis technology (XST) of Xilinx ISE 9.2i tool will be used for synthesis of transmitter and receiver on FPGA Spartan 3E. Keywords: CDMA, DSSS, BPSK, GOLD code.
Performance of OFDM System under Different Fading Channels and Channel CodingjournalBEEI
Orthogonal frequency division multiplexing (OFDM) is a type of multicarrier modulation (MCM) technique in which larger bandwidth is divided into parallel narrow bands each of which is modulated by different subcarriers. All the subcarriers are orthogonal to each other and hence it reduces the interference among various subcarriers. OFDM technique is an efficient modulation technique used in certain wired and wireless application.In a wireless communication channel, the transmitted signal can travel from transmitter to receiver over multiple reflective paths. This results to multipath fading which causes fluctuations in amplitude, phase and angle of arrival of the received signal. For example, the signal which is transmitted from BTS (base transceiver station) may suffer multiple reflections from the buildings nearby, before reaching the mobile station. Such multipath fading channels are classified into slow fading/fast fading and frequency-selective/flat fading channels. This paper discusses the performance of OFDM system using various fading channels and channel coding. The parameter which is known as Bit error rate (BER) is calculated under different fading channels (AWGN, Rayleigh and Rician) for different digital modulation (BPSK, QPSK and QAM) and Channel coding (linear/Cyclic coding). Matlab Simulink tool is used to calculate the BER parameter.
Pmit lecture 03_wlan_wireless_network_2016Chyon Ju
The document discusses requirements and specifications for wireless local area networks (WLANs). It notes that the IEEE 802 committee develops standards for wired and wireless networking, including 802.11 for WLANs. The document then describes several 802.11 specifications such as 802.11, 802.11a, 802.11b, and 802.11g that define transmission speeds and frequencies for WLANs. It also discusses modulation techniques like BPSK and QPSK used in wireless communications.
This document provides an analysis of different pseudorandom and orthogonal spreading sequences used in direct sequence code division multiple access (DS-CDMA). It begins with an introduction to CDMA transmission and reception and an example of direct sequence spread spectrum. It then discusses various pseudorandom sequences like maximal length sequences, Gold sequences, Gold-like sequences, Barker sequences, and Kasami sequences. It also covers orthogonal sequences including Walsh-Hadamard codes, modified Walsh-Hadamard codes, and orthogonal variable spreading factor codes. The document concludes by comparing the performance of these different sequences based on their correlation properties and suitability for use in CDMA networks.
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.
Chapter 6 - Digital Data Communication Techniques 9eadpeer
Digital data communication techniques use asynchronous or synchronous transmission. Asynchronous transmission sends data one character at a time, while synchronous transmission sends data in blocks without start/stop codes. Error detection codes like parity and CRC are added to detect errors, while error correction codes can correct errors by adding redundancy. Line configurations consider topology (star, bus, etc.) and duplex mode (half duplex uses one path while full duplex uses two simultaneous paths).
BER Analysis of OFDM Systems with Varying Frequency Offset Factor over AWGN a...rahulmonikasharma
The document analyzes the effect of varying frequency offset on the bit error rate (BER) performance of orthogonal frequency division multiplexing (OFDM) systems over additive white Gaussian noise (AWGN) and Rayleigh channels through simulation. The simulations show that as the frequency offset increases, the BER performance of the OFDM system degrades in both channel conditions due to increased inter-carrier interference (ICI). Higher frequency offset values lead to worse performance degradation. An effective technique is needed to mitigate the impact of frequency offset on OFDM system performance.
The several assets for high-speed data transmission over wireless uses the Orthogonal Frequency Division
Multiplexing (OFDM) as it is a multicarrier transmission scheme. A large number of narrow bandwidth carriers is
therefore adopted by the OFDM. Individually for an OFDM, each subcarrier is attenuated under the frequency-selective
and fast fading channel, therefore the resulting gain is high attenuation which leads to poor performance of all OFDM
subcarriers if the same fixed transmission scheme are used. Thus the main goal of the indicated paper is to grab an
understanding of the inequality between fixed & adaptive modulations schemes as the introduction of the adaptive
modulation. The need for the above system is to make use of the speaker's voice to check their character and control
approach to administrations, for example, voice dialing data administrations, voice send, and security control for secret
data. The performance of paperwork basically states that implementation of adaptive modulation is done into blocks of
adjacent subcarriers which is the result of dividing whole subcarriers. Therefore the equivalent modulation scheme which
is the calculation of average instantaneous signal to noise (SNR) is exercised to entire subcarriers of the equal block. The
OFDM system average bit error rate (BER) performance is observed here under fixed modulation and adaptive
modulation, and these modulation techniques are recorded by accepting the different inverse fast Fourier transforms
(IFFT) size and uncomplicated adaptive Quadrature amplitude modulation (QAM) strategy. The simulation in MATLAB
shows the results as the performance of fixed modulation is inferior to that of the BER performance of OFDM system
using adaptive modulation. The prospective adaptive modulation and coding Technique uses OFDM to manage the fixed
BER under changing the channel.
Noise Immune Convolutional Encoder Design and Its Implementation in Tanner ijcisjournal
With the rapid advances in integrated circuit(IC) technologies, number of functions on a chip was
increasing at a very fast rate, with which interconnect density is increasing especially in functional logic
chips. The on-chip noise affects are increasing and needs to be addressed. In this paper we have
implemented a convolution encoder using a technique that provides higher noise immunity. The encoder
circuit is simulated in Tanner 15.0 with data rate of 25Mbps and a clock frequency of 250MHz
The document describes a lesson plan for a digital communication course at Matrusri Engineering College. The lesson plan covers linear block codes, including their description, generation, syndrome detection, minimum distance, error correction capabilities, and decoding using standard arrays and Hamming codes over 10 class periods. The objectives are to distinguish different error control coding techniques and their encoding/decoding algorithms. Textbooks and references are also listed.
This document provides an overview of digital communication and covers several topics:
- It describes different types of transmission media including guided media like twisted pair cable, coaxial cable, and fiber optic cable. It also covers unguided or wireless media.
- It discusses characteristics of different transmission media and how signals are transmitted through them. This includes concepts like attenuation, distortion, and noise.
- It defines key terms used to measure signal quality like decibels and signal-to-noise ratio.
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.
The document discusses various types of pulse modulation techniques including pulse amplitude modulation (PAM), pulse width modulation (PWM), pulse position modulation (PPM), and pulse code modulation (PCM). It provides details on the basic principles, components, and advantages of each technique. PCM is described as the digital form of pulse modulation where the analog signal is converted to digital pulses by sampling, quantizing, and encoding the signal. The minimum sampling rate required by the Nyquist theorem and examples of calculating bit rates for PCM are also covered.
1. The document discusses various technical aspects of UMTS link budget design such as typical NodeB and UE sensitivity levels, maximum output power, antenna gain, path loss, dBm, TMA functionality, processing gain, Eb/No targets, pole capacity calculations, and types of handovers.
2. Key information provided includes NodeB sensitivity from -124 to -115 dBm, UE sensitivity from -119 to -105 dBm, maximum NodeB output power of 20-40W, UE maximum transmit power of 21dBm, typical antenna gain of 17dBi, maximum path loss of 135-160dB, and TMA gain of 12dB from noise figure reduction.
3. Calcul
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.
The document provides an overview of source coding in digital communication systems. It discusses the key elements of a communication system including the transmitter, receiver, and channel. It then describes how an analog information source is converted to a digital signal through sampling, quantization, and coding. Source coding aims to remove redundancy in the information so as to minimize the bandwidth required for transmission. Channel coding adds extra bits to help detect and correct errors. Line coding represents the digital bit stream as voltage or current variations suited for the transmission channel. Key techniques discussed include pulse code modulation (PCM), companding, and various line codes.
IJERA (International journal of Engineering Research and Applications) is International online, ... peer reviewed journal. For more detail or submit your article, please visit www.ijera.com
IJERD (www.ijerd.com) International Journal of Engineering Research and Devel...IJERD Editor
The document analyzes the performance of a turbo coded WiMAX system over different communication channels, including AWGN, Rayleigh, and Rician channels. It describes the key components of the WiMAX physical layer, including randomization, forward error correction, interleaving, symbol mapping, and encoding of turbo codes. Simulation results are presented comparing the performance of the different channels, with AWGN showing better performance at higher numbers of turbo code iterations. With convolution coding alone performance was weaker, but turbo coding provided about a 7dB enhancement.
Data detection with a progressive parallel ici canceller in mimo ofdmeSAT Publishing House
The document describes a progressive parallel interference canceller (PPIC) for use in a MIMO-OFDM system to suppress inter-carrier interference (ICI). PPIC is compared to parallel interference canceller (PIC) and shows lower complexity and better performance. PPIC architecture is simpler than PIC and more suitable for implementation in wireless communication systems requiring high data rates and mobility. Simulation results show that PPIC combined with LDPC coding achieves lower bit error rates than PIC combined with LDPC coding.
Cooperative Communication for a Multiple-Satellite Networkchiragwarty
when it comes to space communication
networks, there are many different kinds of space vehicles
that need to communicate with each other, in space as well
as with ground terminals and air borne platform. Example:
Geosynchronous Earth orbit (GEO), Low Earth Orbit
(LEO) satellites and UAVs. There is an ever growing
demand for higher data rates and minimal redundancy, with
satellites and various space platforms travelling at high
speeds relative to each other and relative to the ground
establishing such links can prove to be a real challenge
when Doppler Effect and line of sight (LOS) can play a
significant role in SONET timing and synchronization. As
the number of users grows the space communication links
need to address several types of coding and modulation.
This paper analyzes the use of cooperative communication
techniques for point-to-point and point-to-multipoint
communication links. To this end we start with a simplified
single relay model and proceed to analyze the multi-node
scenarios. We will then apply the amplify-and-forward,
decode-and-forward and coded cooperation protocols to the
best case scenario to compute the efficiency and
synchronization of the link. The single relay and multi-node
scenarios are evaluated on the basis of the signal to noise
(SNR) power received and inter channel interference (ICI).
The intention is to demonstrate the theoretical performance
by simulating outage probability versus spectral efficiency
for different relaying protocols. Subsequently we will show
the effect of cooperative communication on bandwidth
utilization for mobile satellites and space platforms.
introdution to analog and digital communicationSugeng Widodo
This document provides a historical overview of developments in analog and digital communications. It discusses technologies like the telegraph, radio, telephone, electronics, television, digital communications, computer networks, satellite communications, and optical communications. It also describes applications of communications technologies like broadcasting and point-to-point links. Finally, it outlines primary resources for communication systems including transmitted power and channel bandwidth.
This document discusses improving the bit error rate of OFDM transmission using turbo codes. It provides an overview of OFDM and its benefits, including its ability to combat multipath interference. However, OFDM results in burst errors that can degrade coding efficiency. The document proposes using turbo codes with OFDM since turbo codes can achieve performance close to the Shannon limit. It reviews the basic principles of turbo code design and encoding/decoding. The rest of the document outlines simulations done to test the performance of a turbo code combined with OFDM over AWGN and impulsive noise channels.
The document analyzes the performance of LDPC coded WLAN physical layer under BPSK and 16-QAM modulation. It finds that an LDPC encoded WLAN system with a code rate of (48,46) performs best under BPSK modulation in an AWGN channel, achieving the lowest bit error rate. Simulation results show LDPC coding improves performance by reducing bit error rates compared to without coding. The best performing configuration provides power efficiency through lower transmitted power requirements for a given bit error rate.
This document summarizes an article from the International Journal of Research in Advent Technology that proposes an enhanced automatic license plate recognition system. The system aims to overcome issues with existing ALPR techniques like uneven illumination and poor image quality. It develops an ALPR system with four main stages: image acquisition, license plate extraction, license plate segmentation, and character recognition. A key contribution is a methodology to enhance images by eliminating illumination issues before processing, which improves accuracy. The document reviews related literature on existing ALPR techniques and compares their advantages and disadvantages. It then describes the proposed system and experimental results demonstrating its effectiveness at license plate recognition.
This document presents a comparative study of denoising 1-D data using wavelet transform. It studies the impact of different levels of decomposition and thresholding criteria (hard or soft) on output signal-to-noise ratio and mean square error when denoising four synthetic signals (blocks, bumps, doppler, heavy sine) corrupted with white noise using discrete wavelet transform. The results show that for blocks and bumps signals, soft thresholding produced higher output SNR and lower mean square error compared to hard thresholding. Higher levels of decomposition also led to better denoising for blocks but not for bumps.
This document discusses the design and optimization of a steel structure for supporting solar electrical panels. It begins by introducing steel structures and their advantages. It then discusses the existing traditional design process used by manufacturers, which tends to result in overdesigned and heavy structures without using analytical methods. The goal of the project is to introduce finite element analysis to provide a more optimized design that is lighter, lower cost and meets load requirements. Various steel sections will be analyzed and compared in ANSYS to determine the most effective cross section. The analysis will look at deflection, weight and cost to identify a design that maximizes stiffness while minimizing materials usage and expenses. The expected results are an optimized structural design for supporting electrical control panels that uses less material and reduces
BER Analysis of OFDM Systems with Varying Frequency Offset Factor over AWGN a...rahulmonikasharma
The document analyzes the effect of varying frequency offset on the bit error rate (BER) performance of orthogonal frequency division multiplexing (OFDM) systems over additive white Gaussian noise (AWGN) and Rayleigh channels through simulation. The simulations show that as the frequency offset increases, the BER performance of the OFDM system degrades in both channel conditions due to increased inter-carrier interference (ICI). Higher frequency offset values lead to worse performance degradation. An effective technique is needed to mitigate the impact of frequency offset on OFDM system performance.
The several assets for high-speed data transmission over wireless uses the Orthogonal Frequency Division
Multiplexing (OFDM) as it is a multicarrier transmission scheme. A large number of narrow bandwidth carriers is
therefore adopted by the OFDM. Individually for an OFDM, each subcarrier is attenuated under the frequency-selective
and fast fading channel, therefore the resulting gain is high attenuation which leads to poor performance of all OFDM
subcarriers if the same fixed transmission scheme are used. Thus the main goal of the indicated paper is to grab an
understanding of the inequality between fixed & adaptive modulations schemes as the introduction of the adaptive
modulation. The need for the above system is to make use of the speaker's voice to check their character and control
approach to administrations, for example, voice dialing data administrations, voice send, and security control for secret
data. The performance of paperwork basically states that implementation of adaptive modulation is done into blocks of
adjacent subcarriers which is the result of dividing whole subcarriers. Therefore the equivalent modulation scheme which
is the calculation of average instantaneous signal to noise (SNR) is exercised to entire subcarriers of the equal block. The
OFDM system average bit error rate (BER) performance is observed here under fixed modulation and adaptive
modulation, and these modulation techniques are recorded by accepting the different inverse fast Fourier transforms
(IFFT) size and uncomplicated adaptive Quadrature amplitude modulation (QAM) strategy. The simulation in MATLAB
shows the results as the performance of fixed modulation is inferior to that of the BER performance of OFDM system
using adaptive modulation. The prospective adaptive modulation and coding Technique uses OFDM to manage the fixed
BER under changing the channel.
Noise Immune Convolutional Encoder Design and Its Implementation in Tanner ijcisjournal
With the rapid advances in integrated circuit(IC) technologies, number of functions on a chip was
increasing at a very fast rate, with which interconnect density is increasing especially in functional logic
chips. The on-chip noise affects are increasing and needs to be addressed. In this paper we have
implemented a convolution encoder using a technique that provides higher noise immunity. The encoder
circuit is simulated in Tanner 15.0 with data rate of 25Mbps and a clock frequency of 250MHz
The document describes a lesson plan for a digital communication course at Matrusri Engineering College. The lesson plan covers linear block codes, including their description, generation, syndrome detection, minimum distance, error correction capabilities, and decoding using standard arrays and Hamming codes over 10 class periods. The objectives are to distinguish different error control coding techniques and their encoding/decoding algorithms. Textbooks and references are also listed.
This document provides an overview of digital communication and covers several topics:
- It describes different types of transmission media including guided media like twisted pair cable, coaxial cable, and fiber optic cable. It also covers unguided or wireless media.
- It discusses characteristics of different transmission media and how signals are transmitted through them. This includes concepts like attenuation, distortion, and noise.
- It defines key terms used to measure signal quality like decibels and signal-to-noise ratio.
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.
The document discusses various types of pulse modulation techniques including pulse amplitude modulation (PAM), pulse width modulation (PWM), pulse position modulation (PPM), and pulse code modulation (PCM). It provides details on the basic principles, components, and advantages of each technique. PCM is described as the digital form of pulse modulation where the analog signal is converted to digital pulses by sampling, quantizing, and encoding the signal. The minimum sampling rate required by the Nyquist theorem and examples of calculating bit rates for PCM are also covered.
1. The document discusses various technical aspects of UMTS link budget design such as typical NodeB and UE sensitivity levels, maximum output power, antenna gain, path loss, dBm, TMA functionality, processing gain, Eb/No targets, pole capacity calculations, and types of handovers.
2. Key information provided includes NodeB sensitivity from -124 to -115 dBm, UE sensitivity from -119 to -105 dBm, maximum NodeB output power of 20-40W, UE maximum transmit power of 21dBm, typical antenna gain of 17dBi, maximum path loss of 135-160dB, and TMA gain of 12dB from noise figure reduction.
3. Calcul
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.
The document provides an overview of source coding in digital communication systems. It discusses the key elements of a communication system including the transmitter, receiver, and channel. It then describes how an analog information source is converted to a digital signal through sampling, quantization, and coding. Source coding aims to remove redundancy in the information so as to minimize the bandwidth required for transmission. Channel coding adds extra bits to help detect and correct errors. Line coding represents the digital bit stream as voltage or current variations suited for the transmission channel. Key techniques discussed include pulse code modulation (PCM), companding, and various line codes.
IJERA (International journal of Engineering Research and Applications) is International online, ... peer reviewed journal. For more detail or submit your article, please visit www.ijera.com
IJERD (www.ijerd.com) International Journal of Engineering Research and Devel...IJERD Editor
The document analyzes the performance of a turbo coded WiMAX system over different communication channels, including AWGN, Rayleigh, and Rician channels. It describes the key components of the WiMAX physical layer, including randomization, forward error correction, interleaving, symbol mapping, and encoding of turbo codes. Simulation results are presented comparing the performance of the different channels, with AWGN showing better performance at higher numbers of turbo code iterations. With convolution coding alone performance was weaker, but turbo coding provided about a 7dB enhancement.
Data detection with a progressive parallel ici canceller in mimo ofdmeSAT Publishing House
The document describes a progressive parallel interference canceller (PPIC) for use in a MIMO-OFDM system to suppress inter-carrier interference (ICI). PPIC is compared to parallel interference canceller (PIC) and shows lower complexity and better performance. PPIC architecture is simpler than PIC and more suitable for implementation in wireless communication systems requiring high data rates and mobility. Simulation results show that PPIC combined with LDPC coding achieves lower bit error rates than PIC combined with LDPC coding.
Cooperative Communication for a Multiple-Satellite Networkchiragwarty
when it comes to space communication
networks, there are many different kinds of space vehicles
that need to communicate with each other, in space as well
as with ground terminals and air borne platform. Example:
Geosynchronous Earth orbit (GEO), Low Earth Orbit
(LEO) satellites and UAVs. There is an ever growing
demand for higher data rates and minimal redundancy, with
satellites and various space platforms travelling at high
speeds relative to each other and relative to the ground
establishing such links can prove to be a real challenge
when Doppler Effect and line of sight (LOS) can play a
significant role in SONET timing and synchronization. As
the number of users grows the space communication links
need to address several types of coding and modulation.
This paper analyzes the use of cooperative communication
techniques for point-to-point and point-to-multipoint
communication links. To this end we start with a simplified
single relay model and proceed to analyze the multi-node
scenarios. We will then apply the amplify-and-forward,
decode-and-forward and coded cooperation protocols to the
best case scenario to compute the efficiency and
synchronization of the link. The single relay and multi-node
scenarios are evaluated on the basis of the signal to noise
(SNR) power received and inter channel interference (ICI).
The intention is to demonstrate the theoretical performance
by simulating outage probability versus spectral efficiency
for different relaying protocols. Subsequently we will show
the effect of cooperative communication on bandwidth
utilization for mobile satellites and space platforms.
introdution to analog and digital communicationSugeng Widodo
This document provides a historical overview of developments in analog and digital communications. It discusses technologies like the telegraph, radio, telephone, electronics, television, digital communications, computer networks, satellite communications, and optical communications. It also describes applications of communications technologies like broadcasting and point-to-point links. Finally, it outlines primary resources for communication systems including transmitted power and channel bandwidth.
This document discusses improving the bit error rate of OFDM transmission using turbo codes. It provides an overview of OFDM and its benefits, including its ability to combat multipath interference. However, OFDM results in burst errors that can degrade coding efficiency. The document proposes using turbo codes with OFDM since turbo codes can achieve performance close to the Shannon limit. It reviews the basic principles of turbo code design and encoding/decoding. The rest of the document outlines simulations done to test the performance of a turbo code combined with OFDM over AWGN and impulsive noise channels.
The document analyzes the performance of LDPC coded WLAN physical layer under BPSK and 16-QAM modulation. It finds that an LDPC encoded WLAN system with a code rate of (48,46) performs best under BPSK modulation in an AWGN channel, achieving the lowest bit error rate. Simulation results show LDPC coding improves performance by reducing bit error rates compared to without coding. The best performing configuration provides power efficiency through lower transmitted power requirements for a given bit error rate.
This document summarizes an article from the International Journal of Research in Advent Technology that proposes an enhanced automatic license plate recognition system. The system aims to overcome issues with existing ALPR techniques like uneven illumination and poor image quality. It develops an ALPR system with four main stages: image acquisition, license plate extraction, license plate segmentation, and character recognition. A key contribution is a methodology to enhance images by eliminating illumination issues before processing, which improves accuracy. The document reviews related literature on existing ALPR techniques and compares their advantages and disadvantages. It then describes the proposed system and experimental results demonstrating its effectiveness at license plate recognition.
This document presents a comparative study of denoising 1-D data using wavelet transform. It studies the impact of different levels of decomposition and thresholding criteria (hard or soft) on output signal-to-noise ratio and mean square error when denoising four synthetic signals (blocks, bumps, doppler, heavy sine) corrupted with white noise using discrete wavelet transform. The results show that for blocks and bumps signals, soft thresholding produced higher output SNR and lower mean square error compared to hard thresholding. Higher levels of decomposition also led to better denoising for blocks but not for bumps.
This document discusses the design and optimization of a steel structure for supporting solar electrical panels. It begins by introducing steel structures and their advantages. It then discusses the existing traditional design process used by manufacturers, which tends to result in overdesigned and heavy structures without using analytical methods. The goal of the project is to introduce finite element analysis to provide a more optimized design that is lighter, lower cost and meets load requirements. Various steel sections will be analyzed and compared in ANSYS to determine the most effective cross section. The analysis will look at deflection, weight and cost to identify a design that maximizes stiffness while minimizing materials usage and expenses. The expected results are an optimized structural design for supporting electrical control panels that uses less material and reduces
This document describes a proposed VLSI implementation of a high-speed DCT architecture for H.264 video codec design. It presents a Booth radix-8 multiplier-based multiply-accumulate (MAC) unit to improve throughput and minimize area complexity for 8x8 2D DCT computation. The proposed MAC architecture achieves a maximum operating frequency of 129.18MHz while reducing area by 64% compared to a regular merged MAC unit with a conventional multiplier. FPGA implementation and performance analysis demonstrate the suitability of the proposed DCT architecture for applications in HDTV systems.
This document summarizes a study that evaluated the design of an automobile connecting rod using finite element analysis to optimize it for high cycle fatigue strength. The study developed a 3D model of a connecting rod, analyzed stresses under different loading conditions using FEA software, and identified areas of high stress concentration. Six different load cases were considered for the analysis, including bolt preload, inertial forces at various engine speeds, and combined gas and inertial forces. The maximum and minimum bolt preloads were identified as critical parameters for the high cycle fatigue analysis. The study aimed to establish a systematic procedure to evaluate and optimize connecting rod design for fatigue life using finite element modeling.
This document discusses using decision feedback equalization to enhance the performance of optical communication systems. It proposes using a fractionally spaced decision feedback equalizer (FSDFE) combined with activity detection guidance (ADG) and tap decoupling (TD) to improve the equalizer's effectiveness. The FSDFE replaces the symbol spaced feedback filter with a fractionally spaced feedback filter to enhance stability, steady-state error performance, and convergence rate. Adding ADG and TD further improves the steady-state error performance and convergence rate by detecting active taps in the channel impulse response. Simulation results show the FSDFE with ADG and TD offers superior performance to the FSDFE without these techniques, with improved compensation of amplitude distortion.
This document discusses a case and document management software system designed for law firms. It aims to bring together traditional legal work methods with modern technology.
The document first provides background on the important role of documents in legal cases and the need for efficient document management. It then describes the proposed system's features, including legal calendars, document searching and data mining capabilities. Algorithms for document ranking and association pattern mining in customer data are also presented.
The system is analyzed in terms of its potential to improve efficiency for lawyers and law firms by automating routine tasks. It is concluded that the system successfully combines new technology with traditional work styles. Future work may involve developing a mobile app version for increased accessibility.
This document discusses techniques for identifying abnormal vehicle behavior in traffic videos. It begins with an abstract that outlines the goal of detecting abnormal vehicles to improve traffic safety. The introduction then provides context on video surveillance systems and their use in traffic monitoring. The document goes on to discuss specific techniques for object detection, tracking, and classification that can be used to analyze vehicle behavior and identify abnormalities. These include background subtraction, hierarchical background modeling, and classification using features like size and motion. Hidden Markov Models, neural networks, and clustering approaches are also mentioned for modeling vehicle motion and detecting anomalous events.
This document summarizes research on vertical handoff performance in wireless local area networks (WLANs). It examines the data traffic received by different access points as mobile stations move between them. Graphs show how throughput and delay are impacted during handoffs. It also evaluates the performance of file transfer between wireless clients and servers connected by a WLAN backbone network comprising two routers. The document analyzes the effects of station mobility on metrics like traffic, delay, and throughput. In conclusion, it demonstrates vertical handoff triggering between a WiMAX and WLAN network as mobile nodes roam between the base stations.
This document analyzes the seismic and wind effects on steel silo supporting structures. It compares a braced frame structure to an unbraced frame structure. Dynamic analysis was performed using equivalent static and response spectrum methods for earthquake zone V according to Indian codes. The braced system had a higher fundamental natural period and higher base shear values compared to the unbraced system, indicating it provided greater stiffness. The braced system also had lower lateral displacements, showing it performed better under dynamic loading. Overall, the analysis found the braced system to be more economical and effective at resisting seismic and wind loads compared to the unbraced alternative.
This document provides an overview of knowledge management. It discusses how knowledge management is a cross-disciplinary domain that involves managing an organization's knowledge through systematic sharing and creation of knowledge. The general knowledge model outlines the key processes of knowledge creation, retention, transfer, and utilization. Knowledge management techniques help organizations explicate tacit knowledge and share it to gain competitive advantages.
This document summarizes various methods used to remove metal artifacts from dental CT images. It discusses projection completion methods, filtered back projection, maximum likelihood transmission, iterative reconstruction, and linear interpolation methods. The majority of metal artifact reduction methods involve reconstructing images while accounting for metal objects. Key steps include identifying metal regions, interpolating or weighting missing projection data, and iteratively reconstructing images until artifacts are reduced. Compressed sensing methods can also exploit sparsity to reduce artifacts with fewer angular projections.
This document summarizes a research paper on using near field communication (NFC) tags to enable mobile commerce (m-commerce). It discusses how an Android application could read NFC tags on products to add them to a virtual shopping cart. Payment could then be made via the app using existing online payment methods. The document provides background on m-commerce, mobile payments, and how NFC tags work. It also discusses security protocols for NFC-based communications between a user's mobile device and a merchant's terminal for contactless payments. The proposed system aims to make shopping more convenient and efficient for consumers compared to traditional retail models.
This document discusses improving vehicle retrieval through the use of 3D models. It proposes a framework that constructs 3D vehicle models using active shape models, fits the 3D models to 2D images to extract vehicle parts, and rectifies the parts to a reference view. Feature extraction is then performed on the rectified parts, and locality sensitive hashing and inverted indexing are used for efficient vehicle retrieval. The framework aims to improve over existing 2D model-based approaches by leveraging 3D models to handle variations in vehicle appearance better.
This document is a curriculum vitae for Jorge João de Fatima Muginga. It outlines his personal details including his name, date of birth, membership, nationality, marital status and contact information. It also lists his qualifications including degrees from various institutions and training courses completed. Finally, it provides details of his work experience over 15 years in pastry making, import/export management, retail management, and materials and purchasing for an oil company in Angola.
Syed Rizwan Ahmed Kazmi is currently working as a Key Accounts Supervisor and internal auditor at DIGICOM Trading (Pvt) Ltd since August 2014. Previously, he worked as an Emergency Medical Dispatcher at AMAN Foundation from June 2013 to August 2013 and as an Authorization Officer at MCB Bank Limited from April 2007 to March 2013. He has a Bachelor's degree in Commerce and experience working in export management and textiles.
NOISE IMMUNE CONVOLUTIONAL ENCODER DESIGN AND ITS IMPLEMENTATIONIN TANNERIJCI JOURNAL
With the rapid advances in integrated circuit(IC) technologies, number of functions on a chip was increasing at a very fast rate, with which interconnect density is increasing especially in functional logic chips. The on-chip noise affects are increasing and needs to be addressed. In this paper we have implemented a convolution encoder using a technique that provides higher noise immunity. The encoder circuit is simulated in Tanner 15.0 with data rate of 25Mbps and a clock frequency of 250MHz
This document summarizes a research paper that proposes using parallel concatenated turbo codes in wireless sensor networks in an adaptive way. The key points are:
1) Turbo codes can achieve near-Shannon limit performance but decoding is complex, making them difficult to implement on energy-constrained sensor nodes.
2) The proposed approach shifts the complex turbo decoding to the base station while sensor nodes implement encoding and basic error correction.
3) At sensor nodes, a parallel concatenated convolutional code (PCCC) circuit encodes data and detects/corrects errors in forwarded packets. This improves energy efficiency and reliability over the wireless sensor network.
This document discusses channel coding. It defines linear block codes, which encode k information bits into n codeword bits through the addition of n-k check bits. The generator matrix defines the mapping of k message bits to n-bit codewords. Linear block codes have the property that the modulo-2 sum of any two codewords is also a valid codeword. Channel coding introduces redundancy to enable error detection and correction at the receiver. Common channel coding techniques include linear block codes, cyclic codes, and convolutional codes.
A new channel coding technique to approach the channel capacityijwmn
After Shannon’s 1948 channel coding theorem, we have witnessed many channel coding techniques developed to achieve the Shannon limit. A wide range of channel codes is available with different complexity levels and error correction performance. Many powerful coding schemes have been deployed in the power-limited Additive White Gaussian Noise (AWGN) channel. However, it seems like we have arrived at an end of advancement path, for most of the existing channel codes. This article introduces a new coding technique that can either be used as the last coding stage of concatenated coding scheme or in parallel configuration with other powerful channel codes to achieve reliable error performance with moderately complex decoding. We will go through an example to understand the overall approach of the proposed coding technique, and finally we will look at some simulation results over an AWGN channel to demonstrate its potential.
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.
Space time block coding is a technique used in wireless communication to transmit multiple copies of a data stream across a number of antennas and to exploit the various received versions of the data to improve the reliability of data transfer. The fact that the transmitted signal must traverse a potentially difficult environment with scattering, reflection, refraction and so on and may then be further corrupted by thermal noise in the receiver means that some of the received copies of the data may be closer to the original signal than others. This redundancy results in a higher chance of being able to use one or more of the received copies to correctly decode the received signal. In fact, space–time coding combines all the copies of the received signal in an optimal way to extract as much information from each of them as possible.
Vlsi Implementation of Low Power Convolutional Coding With Viterbi Decoding U...IOSR Journals
This document discusses the VLSI implementation of a low power convolutional coding system with Viterbi decoding using finite state machines (FSM). It begins with an introduction to convolutional encoding and Viterbi decoding. It then describes the convolutional encoder which uses a shift register, the state diagram representation, and provides an example of encoding an input sequence. It discusses the Viterbi decoder structure including the branch metric unit, add-compare-select unit, and survivor path memory. It presents the Viterbi algorithm for decoding and shows simulation results of encoding and decoding an input sequence using FSMs. It concludes that the Viterbi algorithm allows for error correction without retransmissions and recovering the original message accurately.
This document summarizes forward error correction techniques using convolutional encoders and Viterbi decoders. It first provides background on communication channels and the need for error correction when transmitting data. It then describes convolutional coding, a technique that maps a continuous stream of input bits to a continuous stream of encoded output bits using shift registers, with the encoded bits depending on current and past input bits. The key aspects of convolutional encoders are discussed, including parameters like the number of output bits, input bits, and shift registers. Generator polynomials are also introduced as characterizing the encoder connections. Viterbi decoding is highlighted as a maximum likelihood algorithm for decoding the trellis structure of convolutional codes based on soft decisions.
IJERA (International journal of Engineering Research and Applications) is International online, ... peer reviewed journal. For more detail or submit your article, please visit www.ijera.com
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 appears to be a student paper submission for a networking course. It discusses using a microwave backhaul link to connect two company branch offices located on different Greek islands. The paper will analyze how the bit error rate of the microwave link at different signal-to-noise ratios can impact the TCP throughput between the two branches. It will include simulations of the microwave link and the network implementation to examine this relationship and draw conclusions. The paper is divided into sections covering the theoretical background of the communication channel, analysis of error correction coding and modulation, and the planned simulations.
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.
COOPERATIVE COMMUNICATIONS COMBINATION DIVERSITY TECHNIQUES AND OPTIMAL POWER...ijaceeejournal
The main task of this article is to focus on the performance of cooperative MIMO relaying in terms of data rate and Power. Furthermore, compare these performances when using Maximum Ratio Combining (MRC) and equal gain combining (EGC).The average SNR improvement of MRC is typically about 5 dB better than with EGC and direct link.The preciseness of the derived closed form expression of optimum power allocation of the DF-based relaying system is demonstrated by simulation results.
Study of the operational SNR while constructing polar codes IJECEIAES
Channel coding is commonly based on protecting information to be communicated across an unreliable medium, by adding patterns of redundancy into the transmission path. Also referred to as forward error control coding (FECC), the technique is widely used to enable correcting or at least detecting bit errors in digital communication systems. In this paper we study an original FECC known as polar coding which has proven to meet the typical use cases of the next generation mobile standard. This work is motivated by the suitability of polar codes for the new coming wireless era. Hence, we investigate the performance of polar codes in terms of bit error rate (BER) for several codeword lengths and code rates. We first perform a discrete search to find the best operational signal-to-noise ratio (SNR) at two different code rates, while varying the blocklength. We find in our extensive simulations that the BER becomes more sensitive to operational SNR (OSNR) as long as we increase the blocklength and code rate. Finally, we note that increasing blocklength achieves an SNR gain, while increasing code rate changes the OSNR domain. This trade-off sorted out must be taken into consideration while designing polar codes for high-throughput application.
Improvement of MFSK -BER Performance Using MIMO Technology on Multipath Non L...theijes
Digital communications has evolved rapidly with a lot of success. The new trend seems to be the reinvention of already existing and even discredited or discarded theories or in this case, channels. Extensive research into optimizing or enhancing already existing schemes is still gaining momentum with practical results for all to experience and utilize. This paper describes the design and BER performance of an M-ary frequency shift keyed (FSK) signaling and demodulation scheme improved by MIMO antenna technology for wireless communications. MFSK and MIMO systems were briefly reviewed including AWGN, Non LOS fading and an important factor employed to estimate the performance of digital transmission. The research was performed using MATLAB for simulation and evaluation of the BER
The document discusses turbo equalization, which is a receiver technique used to mitigate inter-symbol interference in digital communication systems. It works by formulating the channel equalization problem as a turbo decoding problem, where the channel acts as a convolutional code and error correction coding acts as the second code. The turbo equalizer uses iterative exchange of soft information between the equalizer and decoder to jointly estimate transmitted symbols and bits. This iterative process allows both components to improve their estimates in each round and help achieve better performance than traditional equalizers.
AN ANALYSIS OF VARIOUS PARAMETERS IN WIRELESS SENSOR NETWORKS USING ADAPTIVE ...ijasuc
This document analyzes the use of an adaptive forward error correction (FEC) technique in wireless sensor networks to improve various network parameters. It summarizes the results of a simulation study that evaluated throughput, packet delivery ratio, packet loss, delay, and error rate under different numbers of transmitted packets. The main findings are:
1) Throughput and packet delivery ratio increased with the number of transmitted packets when using adaptive FEC, unlike without FEC where performance degraded due to retransmissions.
2) Delay, packet loss, and error rate all decreased as the number of transmitted packets increased, showing that adaptive FEC improved network performance even under higher traffic loads.
3) Adaptively varying the FEC coding
This document summarizes a research paper that examines pricing strategy in a two-stage supply chain consisting of a supplier and retailer. The supplier offers a credit period to the retailer, who then offers credit to customers. A mathematical model is formulated to maximize total profit for the integrated supply chain system. The model considers three cases based on the relative lengths of the credit periods offered at each stage. Equations are developed to represent the profit functions for the supplier, retailer and overall system in each case. The goal is to determine the optimal selling price that maximizes total integrated profit.
The document discusses melanoma skin cancer detection using a computer-aided diagnosis system based on dermoscopic images. It begins with an introduction to skin cancer and melanoma. It then reviews existing literature on automated melanoma detection systems that use techniques like image preprocessing, segmentation, feature extraction and classification. Features extracted in other studies include asymmetry, border irregularity, color, diameter and texture-based features. The proposed system collects dermoscopic images and performs preprocessing, segmentation, extracts 9 features based on the ABCD rule, and classifies images using a neural network classifier to detect melanoma. It aims to develop an automated diagnosis system to eliminate invasive biopsy procedures.
This document summarizes various techniques for image segmentation that have been studied and proposed in previous research. It discusses edge-based, threshold-based, region-based, clustering-based, and other common segmentation methods. It also reviews applications of segmentation in medical imaging, plant disease detection, and other fields. While no single technique can segment all images perfectly, hybrid and adaptive methods combining multiple approaches may provide better results. Overall, image segmentation remains an important but challenging task in digital image processing and computer vision.
This document presents a test for detecting a single upper outlier in a sample from a Johnson SB distribution when the parameters of the distribution are unknown. The test statistic proposed is based on maximum likelihood estimates of the four parameters (location, scale, and two shape) of the Johnson SB distribution. Critical values of the test statistic are obtained through simulation for different sample sizes. The performance of the test is investigated through simulation, showing it performs well at detecting outliers when the contaminant observation represents a large shift from the original distribution parameters. An example application to census data is also provided.
This document summarizes a research paper that proposes a portable device called the "Disha Device" to improve women's safety. The device has features like live location tracking, audio/video recording, automatic messaging to emergency contacts, a buzzer, flashlight, and pepper spray. It is designed using an Arduino microcontroller connected to GPS and GSM modules. When the button is pressed, it sends an alert message with the woman's location, sets off an alarm, activates the flashlight and pepper spray for self-defense. The goal is to provide women a compact, one-click safety system to help them escape dangerous situations or call for help with just a single press of a button.
- The document describes a study that constructed physical fitness norms for female students attending social welfare schools in Andhra Pradesh, India.
- Researchers tested 339 students in classes 6-10 on speed, strength, agility and flexibility tests. Tests included 50m run, bend and reach, medicine ball throw, broad jump, shuttle run, and vertical jump.
- The results showed that 9th class students had the best average time for the 50m run. 10th class students had the highest flexibility on average. Strength and performance generally improved with increased class level.
This document summarizes research on downdraft gasification of biomass. It discusses how downdraft gasifiers effectively convert solid biomass into a combustible producer gas. The gasification process involves pyrolysis and reactions between hot char and gases that produce CO, H2, and CH4. Downdraft gasifiers are well-suited for biomass gasification due to their simple design and ability to manage the gasification process with low tar production. The document also reviews previous studies on gasifier configuration upgrades and their impact on performance, and the principles of downdraft gasifier operation.
This document summarizes the design and manufacturing of a twin spindle drilling attachment. Key points:
- The attachment allows a drilling machine to simultaneously drill two holes in a single setting, improving productivity over a single spindle setup.
- It uses a sun and planet gear arrangement to transmit power from the main spindle to two drilling spindles.
- Components like gears, shafts, and housing were designed using Creo software and manufactured. Drill chucks, bearings, and bits were purchased.
- The attachment was assembled and installed on a vertical drilling machine. It is aimed at improving productivity in mass production applications by combining two drilling operations into one setup.
The document presents a comparative study of different gantry girder profiles for various crane capacities and gantry spans. Bending moments, shear forces, and section properties are calculated and tabulated for 'I'-section with top and bottom plates, symmetrical plate girder, 'I'-section with 'C'-section top flange, plate girder with rolled 'C'-section top flange, and unsymmetrical plate girder sections. Graphs of steel weight required per meter length are presented. The 'I'-section with 'C'-section top flange profile is found to be optimized for biaxial bending but rolled sections may not be available for all spans.
This document summarizes research on analyzing the first ply failure of laminated composite skew plates under concentrated load using finite element analysis. It first describes how a finite element model was developed using shell elements to analyze skew plates of varying skew angles, laminations, and boundary conditions. Three failure criteria (maximum stress, maximum strain, Tsai-Wu) were used to evaluate first ply failure loads. The minimum load from the criteria was taken as the governing failure load. The research aims to determine the effects of various parameters on first ply failure loads and validate the numerical approach through benchmark problems.
This document summarizes a study that investigated the larvicidal effects of Aegle marmelos (bael tree) leaf extracts on Aedes aegypti mosquitoes. Specifically, it assessed the efficacy of methanol extracts from A. marmelos leaves in killing A. aegypti larvae (at the third instar stage) and altering their midgut proteins. The study found that the leaf extract achieved 50% larval mortality (LC50) at a concentration of 49 ppm. Proteomic analysis of larval midguts revealed changes in protein expression levels after exposure to the extract, suggesting its bioactive compounds can disrupt the midgut. The aim is to identify specific inhibitor proteins in the midg
This document presents a system for classifying electrocardiogram (ECG) signals using a convolutional neural network (CNN). The system first preprocesses raw ECG data by removing noise and segmenting the signals. It then uses a CNN to extract features directly from the ECG data and classify arrhythmias without requiring complex feature engineering. The CNN architecture contains 11 convolutional layers and is optimized using techniques like batch normalization and dropout. The system was tested on ECG datasets and achieved classification accuracy of over 93%, demonstrating its effectiveness at automated ECG classification.
This document presents a new algorithm for extracting and summarizing news from online newspapers. The algorithm first extracts news related to the topic using keyword matching. It then distinguishes different types of news about the same topic. A term frequency-based summarization method is used to generate summaries. Sentences are scored based on term frequency and the highest scoring sentences are selected for the summary. The algorithm was evaluated on news datasets from various newspapers and showed good performance in intrinsic evaluation metrics like precision, recall and F-score. Thus, the proposed method can effectively extract and summarize online news for a given keyword or topic.
A review on techniques and modelling methodologies used for checking electrom...nooriasukmaningtyas
The proper function of the integrated circuit (IC) in an inhibiting electromagnetic environment has always been a serious concern throughout the decades of revolution in the world of electronics, from disjunct devices to today’s integrated circuit technology, where billions of transistors are combined on a single chip. The automotive industry and smart vehicles in particular, are confronting design issues such as being prone to electromagnetic interference (EMI). Electronic control devices calculate incorrect outputs because of EMI and sensors give misleading values which can prove fatal in case of automotives. In this paper, the authors have non exhaustively tried to review research work concerned with the investigation of EMI in ICs and prediction of this EMI using various modelling methodologies and measurement setups.
Understanding Inductive Bias in Machine LearningSUTEJAS
This presentation explores the concept of inductive bias in machine learning. It explains how algorithms come with built-in assumptions and preferences that guide the learning process. You'll learn about the different types of inductive bias and how they can impact the performance and generalizability of machine learning models.
The presentation also covers the positive and negative aspects of inductive bias, along with strategies for mitigating potential drawbacks. We'll explore examples of how bias manifests in algorithms like neural networks and decision trees.
By understanding inductive bias, you can gain valuable insights into how machine learning models work and make informed decisions when building and deploying them.
Low power architecture of logic gates using adiabatic techniquesnooriasukmaningtyas
The growing significance of portable systems to limit power consumption in ultra-large-scale-integration chips of very high density, has recently led to rapid and inventive progresses in low-power design. The most effective technique is adiabatic logic circuit design in energy-efficient hardware. This paper presents two adiabatic approaches for the design of low power circuits, modified positive feedback adiabatic logic (modified PFAL) and the other is direct current diode based positive feedback adiabatic logic (DC-DB PFAL). Logic gates are the preliminary components in any digital circuit design. By improving the performance of basic gates, one can improvise the whole system performance. In this paper proposed circuit design of the low power architecture of OR/NOR, AND/NAND, and XOR/XNOR gates are presented using the said approaches and their results are analyzed for powerdissipation, delay, power-delay-product and rise time and compared with the other adiabatic techniques along with the conventional complementary metal oxide semiconductor (CMOS) designs reported in the literature. It has been found that the designs with DC-DB PFAL technique outperform with the percentage improvement of 65% for NOR gate and 7% for NAND gate and 34% for XNOR gate over the modified PFAL techniques at 10 MHz respectively.
Advanced control scheme of doubly fed induction generator for wind turbine us...IJECEIAES
This paper describes a speed control device for generating electrical energy on an electricity network based on the doubly fed induction generator (DFIG) used for wind power conversion systems. At first, a double-fed induction generator model was constructed. A control law is formulated to govern the flow of energy between the stator of a DFIG and the energy network using three types of controllers: proportional integral (PI), sliding mode controller (SMC) and second order sliding mode controller (SOSMC). Their different results in terms of power reference tracking, reaction to unexpected speed fluctuations, sensitivity to perturbations, and resilience against machine parameter alterations are compared. MATLAB/Simulink was used to conduct the simulations for the preceding study. Multiple simulations have shown very satisfying results, and the investigations demonstrate the efficacy and power-enhancing capabilities of the suggested control system.
Using recycled concrete aggregates (RCA) for pavements is crucial to achieving sustainability. Implementing RCA for new pavement can minimize carbon footprint, conserve natural resources, reduce harmful emissions, and lower life cycle costs. Compared to natural aggregate (NA), RCA pavement has fewer comprehensive studies and sustainability assessments.
6th International Conference on Machine Learning & Applications (CMLA 2024)ClaraZara1
6th International Conference on Machine Learning & Applications (CMLA 2024) will provide an excellent international forum for sharing knowledge and results in theory, methodology and applications of on Machine Learning & Applications.
Literature Review Basics and Understanding Reference Management.pptxDr Ramhari Poudyal
Three-day training on academic research focuses on analytical tools at United Technical College, supported by the University Grant Commission, Nepal. 24-26 May 2024
International Conference on NLP, Artificial Intelligence, Machine Learning an...gerogepatton
International Conference on NLP, Artificial Intelligence, Machine Learning and Applications (NLAIM 2024) offers a premier global platform for exchanging insights and findings in the theory, methodology, and applications of NLP, Artificial Intelligence, Machine Learning, and their applications. The conference seeks substantial contributions across all key domains of NLP, Artificial Intelligence, Machine Learning, and their practical applications, aiming to foster both theoretical advancements and real-world implementations. With a focus on facilitating collaboration between researchers and practitioners from academia and industry, the conference serves as a nexus for sharing the latest developments in the field.
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.
1. International Journal of Research in Advent Technology, Vol.2, No.7, July 2014
E-ISSN: 2321-9637
1
Comparison of Single Stage And Double Stage
Interleaver Performance
Sumit Kumar1, Hemant Dalal2
Department of Electronics and Communication1, 2, CBS Group of Institution1, 2
Email: kumarsumit4201990@gmail.com 1, hemantdalal87@gmail.com 2
Abstract- This paper represents the need of error correction codes in communication system. The us eof turbo
code in iterleaver and use of modified turbo code at the interleaver stage enhance the system performance. It
enhance the idea of use and design of double stage interleaver. Such implementation improves the BER of the
system in comparision to single stage interleaver.
Index Terms- CTC, MTC, SNR, BER, ECC.
1. INTRODUCTION
The efficient design of a communication system that
enables reliable high-speed services is challenging.
‘Efficient design’ refers to the efficient use of primary
communication resources such as power and
bandwidth. The reliability of such systems is usually
measured by the required signal-to-noise ratio (SNR)
to achieve a specific bit error rate [John G. Proakis,
2001]. A bandwidth efficient communication system
with perfect reliability, or as reliable as possible using
as low as possible SNR is desired.
Error correction coding (ECC) [C. Heegard,
1999] is a technique that improves the reliability of
communication over a noisy channel. The use of the
appropriate ECC allows a communication system to
operate at very low error rates, using low to moderate
SNR values, enabling reliable high-speed
communication over a noisy channel. Although there
are different types of ECC that can be used for
channel coding, they all have one key objective in
common, namely, achieving a high minimum
Hamming distance to improve the code performance
that occurs only for few codeword.
1.1. Shannon Limit
Both the communication channel and the
signal that travels through it have their own
bandwidth. The bandwidth B of a communication
channel defines the frequency limits of the signals that
it can carry. In order to transfer data very quickly, a
large bandwidth is required. Unfortunately, every
communication channel has a limited bandwidth
In 1948, Shannon’s theory set the
fundamental limits on the efficiency of
communications systems. Shannon theory states that
probability of error in the transmitted data can be
reduced by an arbitrary amount provided that the rate
at which data is transmitted through the channel does
not exceed the channel capacity and formulated by
Shannon as:
…(1.1)
With C being the channel capacity, the
maximum amount of bits that can be transmitted
through the channel per unit of time, W the bandwidth
of the channel and S/N being the signal to noise ratio
(SNR) at the receiver.
This theory went against the conventional
methods of that time, which consisted of lowering
probability of error by raising SNR, means by
increasing the power of the transmitted signal.
Unfortunately, although Shannon’s theorem sets down
the fundamental limitations upon the on
communication efficiency, it provides no methods
through which these limits can be reached.
1.2. Channel coding
The task of channel coding is to encode the
information sent over a communication channel in
such a way that in the presence of channel noise,
errors can be detected and/or corrected. There are two
types of channel coding technique.
1.2.1. Backward Error Correction (BEC) Coding
Technique
Backward error correction [John G. Proakis,
2001] is a technique used for error detection only. At
the receiver error can be detected by the redundancy
bits added by the encoder at the transmitter but can
not be corrected at the receiver end. If an error is
detected, the sender is requested to retransmit the
message. While this method is simple and sets lower
requirements on the code’s error-correcting
properties, it on the other hand requires duplex
communication and causes undesirable delays in
transmission. This technique is used where delay in
the transmission can be tolerated.
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1.2.2. Forward Error Correction (FEC)
Coding Technique
Forward error correction [John G. Proakis,
2001] is a technique used for error detection as well as
correction at the receiver end. In FEC technique
redundancy bits are added to the information bits
using channel encoder. If an error is detected at the
receiver end, the message in not retransmitted, while
it is corrected using redundancy bits added by channel
encoder. In FEC technique channel decoder is capable
of detecting as well as correcting a certain numbers of
errors, i.e. it is capable of locating the position of
error. Number of error that can be corrected at the
receiver end depends on how much bit error
correcting code is used at the transmitter end by the
channel encoder. An N bit error correcting code can
detect N+1 bit of error and correct N bit error. Since
FEC codes require only simplex communication, they
are especially attractive in wireless communication
systems. FEC technique improves the energy
efficiency of such systems. Designing a channel code
is always a trade-off between energy efficiency and
bandwidth efficiency. Codes with lower rate (i.e.
bigger redundancy) can usually correct more errors
[Molisch, 2011]. If more errors can be corrected, the
communication system can operate with a lower
transmit power, transmit over longer distances,
tolerate more interference, use smaller antennas and
transmit at a higher data rate. These properties make
the code energy efficient. On the other hand, low-rate
codes have a large overhead and are hence consume
more bandwidth. Also, decoding complexity grows
exponentially with code length, and long (low-rate)
codes set high computational requirements to
conventional decoders.
There is a theoretical upper limit on the data
transmission rate R, for which error-free data
transmission is possible. This limit is called channel
capacity or also Shannon capacity. Although Shannon
developed his theory already in the 1940s, several
decades later the code designs were unable to come
close to the theoretical limit due to decoder
complexity.
Hence, new codes were sought that would
allow for easier decoding. One way of making the
task of the decoder easier is using a code with mostly
high-weight code words. High-weight code words, i.e.
code words containing more ones and less zeros, can
be distinguished more easily. Another strategy
involves combining simple codes in a parallel fashion
[Li. Ping, 2001], so that each part of the code can be
decoded separately with less complex decoders and
each decoder can gain from information exchange
with others. This is called the divide-and-conquer
strategy. Turbo codes use second method to achieve
near Shannon limit performance.
2. SYSTEM DESIGN
CTC encoder consists of parallel concatenation of two
rate RSC encoders using random
Interleaver. Fig. 1 below shows component used to
design this turbo encoder block. Parameter trellis
structure defines number of state, constrained length,
code generator and feedback connection for
convolutional encoder. Trellis structure is given by
generator polynomial. Random interleaver interleaves
the information bit sequence using random
permutations.
Fig. 1 TCC Encoder
Deinterlacer separates the elements of the input signal
to generate the output signals. The odd-numbered
elements of the input signal become the first output
signal, while the even-numbered elements of the input
signal become the second output signal. To adjust
code rate from to the odd bit
sequence of second convolutional encoder is
terminated. Parameters used for different component
of CTC encoder are shown below in the table 1.1.
Table 1.1 parameters for CTC encoder
RSC
Encoder
Parameters Values
Trellis Poly2trellis(5, [37 21],37)
Output Truncated (reset every frame)
Random
Interleaver
No. of Element 1024*128
Initial seed 54123
· Parallel to serial converter and Serial to
Parallel Converter
Parallel to serial converter is used in the
transmitter to concatenate output of Deinterlacer to
transmit signal through the channel. At the receiver
end the received signal is converted back to parallel
form using select row block.
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· Puncturing and Padding Zeros
Puncturing is used to adjust code rate at the
transmitting end. Puncturing vector define puncturing
vector. The puncturing vector used is .
Puncturing vector shows that and bit of
every six bit is not transmitted. Padding zeros block is
used at the receiving end. Zeros are padded using
same vector as puncturing vector used at the
transmitting end. Two zeros are added for every four
bits of received signal. Zeros are added at the position
of punctured bit.
· AWGN channel
AWGN channel add white Gaussian noise to
the input signal. The input and output signals can be
real or complex. When the input signal is real this
block adds real Gaussian noise and produces a real
output signal. When the input signal is complex, this
block adds complex Gaussian noise and produces a
complex output signal. Probability distribution for
noise is Gaussian distribution depends on the
variance. Variance of the channel is calculated using
the equation 3.1.
…(2)
· Iterative SISO decoder
SISO iterative decoder is used for decoding
turbo code. Soft information is exchanged between
two decoders. Soft output ( ) of first decoder is
used by second decoder after interleaving, to make a
decision about APP of information bits. Soft output of
second decoder is fed back to first decoder after
deinterleaving and suitable delay. Random
deinterleaver is used and delay value should be
multiple of interleaver length. APP of parity bits is
terminated using terminator.
Fig.2 Iterative SISO CTC Decoder
Table 1.2 Parameters for SISO Decoder
Name of Block Parameter Value
APP
Convolutional
decoder
trellis Poly2trellis
(5, [37 21],37)
Termination
Method
Truncated
Number of
Scaling Bits
3
Decoding
Algorithm
Max Log MAP
Random
Interleaver
and Deinterleaver
Number of
Elements
1024*128
Seed 54123
Delay Delay Samples 1024*128
Hard decision about the information bits is
made by likelihood to binary transformation block.
Information bit is decoded as one if its APP is greater
than positive otherwise decoded as zero.
· Error Rate Calculation
The Error Rate Calculation block compares
input data from the transmitter with input data from
the receiver. It calculates the error rate by dividing the
total number of unequal pairs of data elements by the
total number of input data elements from one source.
This block can be used to compute either symbol or
bit error rate, because it does not consider the
magnitude of the difference between input data
elements. If the inputs are bits, then the block
computes the bit error rate. If the inputs are symbols,
then it computes the symbol error rate. The block
output is a three-element vector consisting of the error
rate, followed by the number of errors detected and
the total number of symbols compared. This vector
can be sent to either the workspace or an output port.
Table 3.4 shows parameter used for error rate
calculation block.
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Table 1.3 Parameter for Error Rate Calculation
Parameter Value
Receive Delay 0
Computation Delay 0
Computation mode Entire Frame
Output Data Port
· Display
Display block display the value of BER
calculated by error rate calculation block. The amount
of data that appears and the time steps at which the
data appears depend on the Decimation block
parameter and the Sample Time. The Decimation
parameter enables to display data at every nth sample,
where n is the decimation factor. The default
decimation, 1, displays data at every time step. The
Sample Time, which can be set with set_param,
specifies a sampling interval at which to display
points.
Table 1.4 Parameter for Display
Parameter Value
Output Format Short
Decimation 1
Turbo Decoder
In a typical communications receiver, a
demodulator is often designed to produce soft
decisions, which are then transferred to a decoder.
Such a decoder could be called a soft input/hard
output decoder. With turbo codes, where two or more
component codes are used, and decoding involves
feeding outputs from one decoder to the inputs of
other decoders in an iterative fashion, a hard-output
decoder would not be suitable. That is because hard
decisions as input to a decoder degrade system
performance (compared to soft decisions). Hence,
what is needed for the decoding of turbo codes is a
soft input/soft output decoder [J. Hagenauer, 1995]. A
decoding algorithm that accept a priori information as
its input and produces a posteriori information as its
output is called a soft input soft output algorithm.
Fig.3 shows the schematic diagram for SISO
turbo iterative decoding [C. Berrou, 1996]. It consists
of two SISO decoder connected in a closed fashion
through interleaver and deinterleaver. The two
decoders exchange their soft information to improve
their estimates for information sequence.
Fig. 3 SISO Turbo Decoder structure
First decoder takes as input the received
information sequence, output codeword of encoder1
and soft information feedback from second decoder.
Second decoder produce a priori probability estimate
of the information sequence using the soft output
produced by first decoder and output codeword of
second encoder. After a certain number of iteration
the output of the two decoders become nearly same
and improvement in the performance due to
information exchange becomes negligible. SISO
decoder stops further iteration and output of the last
stage output make a hard decision of the information
sequence.
There are two main algorithms to decode the
data. One is Viterbi Algorithm (VA) [G. D. Forney,
1973] and the other one is Maximum A Posteriori
Algorithm (MAP) [P. Robertson, 1995]. The first
algorithm finds the most probable output data
sequence. The trellis diagram is drawn and the path
with the least Hamming distance is found. The MAP
algorithm finds the marginal probability that the
received bit was 1 or 0. Since the bit could occur in
many different codeword, the sum of all the
probabilities is considered. The MAP algorithm is
preferred as it minimises the bit error probability.
3. SIMULATION RESULTS
Simulation result shows that BER performance
improves as signal to noise ratio increases and BER
converges at a good rate as signal to noise ratio
increases. From the simulation result it is observed
that, as the number of iterations increases BER
performance improves.
BER performance of the system improves for iterative
decoding as number of iteration increases. Ideally
iterative decoding is stopped when APP of both the
decoder is exactly equal. This will take a long time to
decode information bit sequence so iterative decoding
is stopped when improvement in BER performance of
successive iteration is nearly equal. Hard decision
about the information bit is taken when BER
performance for successive iteration shows no
improvement. We obtain different results for MTC
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with double stage interleaver and compare single
stage and double stage interleaver.
100
10-1
10-2
10-3
-20 -15 -10 -5 0 5
Eb/No, dB
B it E rro r R a te
Bit error probability curve for BPSK modulation
theory
double stage interleave with rate1/3
Fig. 4 BER for code rate 1/3 for double stage
interleaver
100
10-1
10-2
10-3
-20 -15 -10 -5 0 5
Eb/No, dB
B it E rror Rate
Bit error probability curve for BPSK modulation
theory
double stage interleave with rate1/2
Fig. 5 BER for code rate 1/2 for double stage
interleaver
100
10-1
10-2
10-3
-20 -15 -10 -5 0 5
Eb/No, dB
B it E rror Rate
Bit error probability curve for BPSK modulation
theory
double stage interleave with rate2/3
Fig. 6 BER for code rate 2/3 for double stage
interleaver
0
10
-1
10-2
10-3
-20 -15 -10 -5 0 5
10
Eb/No, dB
Bit Error Rate
Bit error probability curve
theory
single stage interleaver
double stage interleaver
Fig. 7 Comparison of BER of single stage and double
stage interleaver.
4. CONCLUSION
Conclusion from this research work is that
decoder complexity is reduced by a factor of nearly
two for MTC as compared to CTC with a negligible
loss of BER performance. This loss of BER is
compensated by reduction of decoder complexity.
Memory requirement is much less for decoding MTC
as compared to CTC. Double stage interleaver
performs much better than the single stage interleaver.
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