This document summarizes a research paper that compares the performance of 32QAM and 64QAM digital modulation techniques when used with OFDM for 4G networks. It finds that 32QAM has better performance with lower bit and packet loss over 64QAM. Specifically, when transmitting 1920 bits over an AWGN channel, 32QAM had 65 bit losses and 0 packet losses, while 64QAM had 80 bit losses and 0.04167 packet losses. Therefore, the document concludes 32QAM can be more efficiently used than 64QAM for digital transmission in 4G networks when combined with OFDM modulation.
An Approach to Improve the Quality of Service in OFDMA Relay Networks via Re-...iosrjce
With the next-generation cellular networks making a transition toward smaller cells, two-hop
orthogonal frequency-division multiple access (OFDMA) relay networks have become a dominant, mandatory
component in the 4G standards (WiMAX802.16j, 3GPP LTE-Adv.). Here we are using the multicasting strategy
Given the growing importance of multimedia broadcast and multicast services (MBMS) in 4G networks, the
latter forms the focus of this project. The main aim of this project is to improve the performance of the OFDMA
based relay networks. The OFDMA transmission Scheme is a widely accepted scheme for improving the quality
and speed of communication over the 4G cellular network. There are two different models designed for OFDMA
relay networks .Distributed (DP) and Contiguous (CP) permutations. We are checking the performance of two
algorithms The linear programming algorithm and the greedy algorithm by using two models of OFDMA for
multicast scheduling and after performance evaluation we select the best model and the algorithm for
transmission. We further improve the throughput via retransmission of lost packets during data transfer over the
specified network. We can detect the packet loss by packet synchronization technique and a request will be sent
by the destination for re-sending the lost packets which is called as Re-Transmission.[1]
An Efficient Data Communication Using Conventional CodesIJERA Editor
The BER performance of conventional FFT-OFDM system is compared with DWT-OFDM system and DCT-OFDM system in an AWGN environment and Saleh-Valenzuela (SV) channel model at 60 GHz. Several wavelets such as Haar, Daubechies, Symlet, biorthogonal are considered. The BER is calculated for signaling format BPSK and the performance is analyzed at 60 GHz. Simulation results show that DCT based scheme yields the lowest average bit error rate. While out of all wavelet mother used Haar and Daubechies wavelet based scheme yields lower BER than FFT-OFDM for an AWGN channel. But it may include the implementation of forward error correction techniques such as convolution codes. An efficient channel estimation algorithm may be included for performance evaluation of DCT-OFDM and DWT- OFDM working at 60 GHz band. We introduce the Interfacing Techniques for Accessing data transfer data delivery. By using our approach we are increasing the efficiency of the data communication.
PERFORMANCE EVALUATION OF MC-CDMA SYSTEM OVER RAYLEIGH FADING CHANNELIJCSES Journal
Multi Carrier Code Division Multiple Access (MC-CDMA) is a well known technique for high speed
wireless data transmission .Two advanced technology was included in the MC-CDMA structure, such as
orthogonal frequency division multiplex (OFDM) and the code division multiple access (CDMA),so that it
benefits from the robustness of OFDM against multipath environment and from the capability of multiuser
multiplexing services that is achieved via (CDMA) system. MC-CDMA is a multicarrier spread spectrum
system which is classified as the candidate scheme for future mobile radio systems. In this paper MCCDMA
system, with Rayleigh fading channel and 16QAM array modulation, was simulated to investigate
the effects of different parameters on the system performance, such as processing gain; number of paths;
number of users; interleaving; and coding ratio.MC-CDMA performances can be considerably improved
by proper selection of these parameters. As expected, results show that MC-CDMA has a better performance over CDMA system.
UMTS/3G RAN Capacity Management Guideline Part-02 (Sectorization))Md Mustafizur Rahman
UMTS RAN capacity management is one of the Key activities to maintain the good QoS & stability of the 3G system. A relatively high load can affect the accessibility, coverage and QoS of established services. The capacity, coverage and QoS of the WCDMA system are mutually affected. Hence, for a stable & good quality 3G network, UMTS capacity need to be monitored, expanded & manage regularly.
In the first part of document (Part-1) UMTS soft capacity management along with the correlation between capacity vs accessibility, UMTS expansion threshold, counters & effective mechanism of UMTS Soft capacity management have been depicted. This part of the Document is focused on UMTS Hard Expansion Methodology. 3G Capacity management by Sectorization has been explained thoroughly.
After completing this, you will be able to gain knowledge on 3G Expansion Parameters, 3G Expansion Threshold, Capacity Gain, Cost vs Capacity Gain by Sectorization. Moreover, you will be familiar with Planning, Optimization & Post Performance activities of Sectorization.
Quality of Service for Video Streaming using EDCA in MANETijsrd.com
Mobile Ad-hoc network(MANET) is a collection of wireless terminals that are able to dynamically form a temporary network. To establish such a network no fixed infrastructure is required. Here, it is the responsibility of network nodes to forward each other's packets and thus these nodes also act as routers. In such a network resources are limited and also topology changes dynamically. So providing Quality of service(QoS) is also necessary. QoS is more important for real time applications for example Video Streaming. IEEE 802.11e network standard supports QoS through EDCA technique. This technique does not fulfill the requirements of QoS. So, in this project modified EDCA technique is proposed to enhance QoS for Video Streaming application. This technique is implemented in NS2 and compared with traditional EDCA.
RESOURCE ALLOCATION ALGORITHMS FOR QOS OPTIMIZATION IN MOBILE WIMAX NETWORKSijwmn
WiMAX is based on the standard IEEE 802.16e-2009 for wireless access in Metropolitan Area Networks. It
is one of the solutions for 4G IP based wireless technology. WiMAX utilizes Orthogonal Frequency
Division Multiple Access which also supports Multicast and Broadcast Service with appropriate
Modulation and Coding Scheme. Presently, Scheduling and Resource allocation algorithm in Opportunistic
Layered Multicasting provides multicasting of layered video over mobile WiMAX to ensure better QoS.
Initially, the knowledge based allocation of subcarriers is used for scheduling. In addition, to reduce the
burst overhead, delay and jitter, SWIM (Swapping Min-Max) algorithm is utilized. Another promising
technology that can greatly improve the system performance by exploring the broadcasting nature of
wireless channels and the cooperation among multiple users is the Cooperative Multicast Scheduling
(CMS) technique. The simulation results show, Swapping Min-Max performs better with lesser number of
bursts, Zero jitter and with optimal throughput. The results with Cooperative Multicast Scheduling show
the enhanced throughput for each member in the Multicasting Scenario.
An Approach to Improve the Quality of Service in OFDMA Relay Networks via Re-...iosrjce
With the next-generation cellular networks making a transition toward smaller cells, two-hop
orthogonal frequency-division multiple access (OFDMA) relay networks have become a dominant, mandatory
component in the 4G standards (WiMAX802.16j, 3GPP LTE-Adv.). Here we are using the multicasting strategy
Given the growing importance of multimedia broadcast and multicast services (MBMS) in 4G networks, the
latter forms the focus of this project. The main aim of this project is to improve the performance of the OFDMA
based relay networks. The OFDMA transmission Scheme is a widely accepted scheme for improving the quality
and speed of communication over the 4G cellular network. There are two different models designed for OFDMA
relay networks .Distributed (DP) and Contiguous (CP) permutations. We are checking the performance of two
algorithms The linear programming algorithm and the greedy algorithm by using two models of OFDMA for
multicast scheduling and after performance evaluation we select the best model and the algorithm for
transmission. We further improve the throughput via retransmission of lost packets during data transfer over the
specified network. We can detect the packet loss by packet synchronization technique and a request will be sent
by the destination for re-sending the lost packets which is called as Re-Transmission.[1]
An Efficient Data Communication Using Conventional CodesIJERA Editor
The BER performance of conventional FFT-OFDM system is compared with DWT-OFDM system and DCT-OFDM system in an AWGN environment and Saleh-Valenzuela (SV) channel model at 60 GHz. Several wavelets such as Haar, Daubechies, Symlet, biorthogonal are considered. The BER is calculated for signaling format BPSK and the performance is analyzed at 60 GHz. Simulation results show that DCT based scheme yields the lowest average bit error rate. While out of all wavelet mother used Haar and Daubechies wavelet based scheme yields lower BER than FFT-OFDM for an AWGN channel. But it may include the implementation of forward error correction techniques such as convolution codes. An efficient channel estimation algorithm may be included for performance evaluation of DCT-OFDM and DWT- OFDM working at 60 GHz band. We introduce the Interfacing Techniques for Accessing data transfer data delivery. By using our approach we are increasing the efficiency of the data communication.
PERFORMANCE EVALUATION OF MC-CDMA SYSTEM OVER RAYLEIGH FADING CHANNELIJCSES Journal
Multi Carrier Code Division Multiple Access (MC-CDMA) is a well known technique for high speed
wireless data transmission .Two advanced technology was included in the MC-CDMA structure, such as
orthogonal frequency division multiplex (OFDM) and the code division multiple access (CDMA),so that it
benefits from the robustness of OFDM against multipath environment and from the capability of multiuser
multiplexing services that is achieved via (CDMA) system. MC-CDMA is a multicarrier spread spectrum
system which is classified as the candidate scheme for future mobile radio systems. In this paper MCCDMA
system, with Rayleigh fading channel and 16QAM array modulation, was simulated to investigate
the effects of different parameters on the system performance, such as processing gain; number of paths;
number of users; interleaving; and coding ratio.MC-CDMA performances can be considerably improved
by proper selection of these parameters. As expected, results show that MC-CDMA has a better performance over CDMA system.
UMTS/3G RAN Capacity Management Guideline Part-02 (Sectorization))Md Mustafizur Rahman
UMTS RAN capacity management is one of the Key activities to maintain the good QoS & stability of the 3G system. A relatively high load can affect the accessibility, coverage and QoS of established services. The capacity, coverage and QoS of the WCDMA system are mutually affected. Hence, for a stable & good quality 3G network, UMTS capacity need to be monitored, expanded & manage regularly.
In the first part of document (Part-1) UMTS soft capacity management along with the correlation between capacity vs accessibility, UMTS expansion threshold, counters & effective mechanism of UMTS Soft capacity management have been depicted. This part of the Document is focused on UMTS Hard Expansion Methodology. 3G Capacity management by Sectorization has been explained thoroughly.
After completing this, you will be able to gain knowledge on 3G Expansion Parameters, 3G Expansion Threshold, Capacity Gain, Cost vs Capacity Gain by Sectorization. Moreover, you will be familiar with Planning, Optimization & Post Performance activities of Sectorization.
Quality of Service for Video Streaming using EDCA in MANETijsrd.com
Mobile Ad-hoc network(MANET) is a collection of wireless terminals that are able to dynamically form a temporary network. To establish such a network no fixed infrastructure is required. Here, it is the responsibility of network nodes to forward each other's packets and thus these nodes also act as routers. In such a network resources are limited and also topology changes dynamically. So providing Quality of service(QoS) is also necessary. QoS is more important for real time applications for example Video Streaming. IEEE 802.11e network standard supports QoS through EDCA technique. This technique does not fulfill the requirements of QoS. So, in this project modified EDCA technique is proposed to enhance QoS for Video Streaming application. This technique is implemented in NS2 and compared with traditional EDCA.
RESOURCE ALLOCATION ALGORITHMS FOR QOS OPTIMIZATION IN MOBILE WIMAX NETWORKSijwmn
WiMAX is based on the standard IEEE 802.16e-2009 for wireless access in Metropolitan Area Networks. It
is one of the solutions for 4G IP based wireless technology. WiMAX utilizes Orthogonal Frequency
Division Multiple Access which also supports Multicast and Broadcast Service with appropriate
Modulation and Coding Scheme. Presently, Scheduling and Resource allocation algorithm in Opportunistic
Layered Multicasting provides multicasting of layered video over mobile WiMAX to ensure better QoS.
Initially, the knowledge based allocation of subcarriers is used for scheduling. In addition, to reduce the
burst overhead, delay and jitter, SWIM (Swapping Min-Max) algorithm is utilized. Another promising
technology that can greatly improve the system performance by exploring the broadcasting nature of
wireless channels and the cooperation among multiple users is the Cooperative Multicast Scheduling
(CMS) technique. The simulation results show, Swapping Min-Max performs better with lesser number of
bursts, Zero jitter and with optimal throughput. The results with Cooperative Multicast Scheduling show
the enhanced throughput for each member in the Multicasting Scenario.
A low complexity partial transmit sequence scheme for better papr reduction i...eSAT Journals
Abstract The main drawback of OFDM system is the high Peak to Average Power Ratio (PAPR) of the transmitted signals. Partial transmit sequence scheme is a promising algorithm to reduce the peak-to-average power ratio (PAPR) in orthogonal frequency division multiplexing (OFDM). The Partial Transmit Sequence (PTS) consist of several inverse fast Fourier transform (IFFT) operations and complicated calculations to obtain optimum phase sequence which results in increasing the computational complexity of PTS. A phase sequence applied to the PTS Scheme reduces its complexity but at the expense of slight degradation in PAPR reduction. In this paper, for further reduction of PAPR the peak clipping of the OFDM signal is introduced along with the PTS with new phase sequence scheme. Since clipping is one of the simplest techniques of PAPR reduction, it does not increase the complexity of the system much and a better PAPR reduction is obtained with the combined effect of clipping and PTS with New Phase Sequence. But the clipping technique introduce some distortion in the signal, however peak clipping of signal below a particular threshold can maintain the BER in the tolerable range. The clipping threshold selected will be different for different OFDM systems. Index Terms: OFDM, Peak to Average Power Ratio (PAPR), Partial Transmit Sequence (PTS), Clipping.
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology.
This slide includes
Advanced multiplexing
Code Division Multiplexing
Dense Wavelength Division Multiplexing
OFDM
Connectionless
LAN
L3 SWTICH
SLIP
PPP
CORE AND DISTRIBUTION NETWORKS.
GSM-Mobility Management-Call Control
GRPS-Network elements
Radio Resource Management
Mobility Management and Session Management
Small Screen Web Browsing
UTRAN-Core and Radio Network Mobility Management
UMTS Security
International Journal of Engineering Research and Development (IJERD)IJERD Editor
journal publishing, how to publish research paper, Call For research paper, international journal, publishing a paper, IJERD, journal of science and technology, how to get a research paper published, publishing a paper, publishing of journal, publishing of research paper, reserach and review articles, IJERD Journal, How to publish your research paper, publish research paper, open access engineering journal, Engineering journal, Mathemetics journal, Physics journal, Chemistry journal, Computer Engineering, Computer Science journal, how to submit your paper, peer reviw journal, indexed journal, reserach and review articles, engineering journal, www.ijerd.com, research journals,
yahoo journals, bing journals, International Journal of Engineering Research and Development, google journals, hard copy of journal
In this paper, we discussed about LTE system throughput calculation for both TDD and FDD system.
3GPP LTE technology support both TDD and FDD multiplexing. The paper describes all the factors which affect the throughput like Bandwidth, Modulation, UE category and mulplexing. It also describes how we get throughput 300Mbps in DL and 75Mbps in UL and what are assumptions taken to calculate the same.
Paper describes the steps and formulae to calculate the throughput for FDD system for TDD Config 1 and Config 2.
The throughput calculations shown in this paper is theoretical and limited by the assumptions taken to calculate for calculations
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.
Motivation and results coverage enhancment for 3GPP NR Rel.17 Eiko Seidel
In this paper we would like to emphasize once again the need to look at large coverage scenarios for 5G NR and express our support for the creation of a Rel.17 work item. Furthermore, we provide first system-level simulation results to further motivate work on coverage enhancements and prove our commitment to contribute to a study item in the working groups in Rel.17 with independent performance evaluation.
COMPARISON OF BIT ERROR RATE PERFORMANCE OF VARIOUS DIGITAL MODULATION SCHEME...ijasa
Digital modulation increases information capacity, data security, and system availability while maintaining high communication quality. As a result, digital modulation techniques are in higher demand than analog modulation techniques due to their ability to transmit larger amounts of data. Amplitude Shift Keying (ASK), Frequency Shift Keying (FSK), Phase Shift Keying (PSK), Differential Phase Shift Keying (DPSK), and Quadrature Amplitude Modulation (QAM) are critical components of current communications systems development, particularly for broadband wireless communications. In this paper, the comparison of bit error rate performance of different modulation schemes (BPSK, QPSK, and16-QAM) and various equalization techniques such as constant modulus algorithm (CMA) and maximum likelihood sequence estimate (MLSE) for the AWGN and Rayleigh fading channels is analyzed using Simulink. BPSK outperforms QPSK and 16-QAM when compared to the other two digital modulation schemes. Among the three digital modulation schemes, BPSK is showing better performance as compared to QPSK and 16- QAM
Performance Analysis of Wireless Networks With MDQOSIJERA Editor
In Wireless/Mobile networks various kinds of encoding schemes were used for transmission of data over a bandwidth. The desired quality and generated traffic varies with the requirement with this bandwidth. A generic video telephony may require more than 40 kbps whereas a low motion video telephony may require about 25 kbps for data transmission. From the designing point of view these requirements demands for an alternative resource planning, especially for bandwidth allocation in wireless networks. In wireless network where bandwidth is a scare resource, the system may need to block incoming user if all of the bandwidth has been used to provide highest quality of service to existing users. However this bandwidth resource planning may be unacceptable for larger application. A degradable approach to multiple users can be made on bandwidth allocation to reduce the blocking probability without degrading the quality of service to existing users.
This work aims towards a realization of a wireless/mobile network using W-CDMA multi access technique supporting multilevel quality of services. The bandwidth allocation to multiple users is adjusted dynamically according to the required network condition so as to increase bandwidth utilization. The work analyze the performance deriving the degradation period ratio, mean degradation time and degradation state for the implemented wireless network.The proposed work is aim to implement on Matlab tool for its functional verification considering various mobility patterns
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology
A low complexity partial transmit sequence scheme for better papr reduction i...eSAT Journals
Abstract The main drawback of OFDM system is the high Peak to Average Power Ratio (PAPR) of the transmitted signals. Partial transmit sequence scheme is a promising algorithm to reduce the peak-to-average power ratio (PAPR) in orthogonal frequency division multiplexing (OFDM). The Partial Transmit Sequence (PTS) consist of several inverse fast Fourier transform (IFFT) operations and complicated calculations to obtain optimum phase sequence which results in increasing the computational complexity of PTS. A phase sequence applied to the PTS Scheme reduces its complexity but at the expense of slight degradation in PAPR reduction. In this paper, for further reduction of PAPR the peak clipping of the OFDM signal is introduced along with the PTS with new phase sequence scheme. Since clipping is one of the simplest techniques of PAPR reduction, it does not increase the complexity of the system much and a better PAPR reduction is obtained with the combined effect of clipping and PTS with New Phase Sequence. But the clipping technique introduce some distortion in the signal, however peak clipping of signal below a particular threshold can maintain the BER in the tolerable range. The clipping threshold selected will be different for different OFDM systems. Index Terms: OFDM, Peak to Average Power Ratio (PAPR), Partial Transmit Sequence (PTS), Clipping.
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology.
This slide includes
Advanced multiplexing
Code Division Multiplexing
Dense Wavelength Division Multiplexing
OFDM
Connectionless
LAN
L3 SWTICH
SLIP
PPP
CORE AND DISTRIBUTION NETWORKS.
GSM-Mobility Management-Call Control
GRPS-Network elements
Radio Resource Management
Mobility Management and Session Management
Small Screen Web Browsing
UTRAN-Core and Radio Network Mobility Management
UMTS Security
International Journal of Engineering Research and Development (IJERD)IJERD Editor
journal publishing, how to publish research paper, Call For research paper, international journal, publishing a paper, IJERD, journal of science and technology, how to get a research paper published, publishing a paper, publishing of journal, publishing of research paper, reserach and review articles, IJERD Journal, How to publish your research paper, publish research paper, open access engineering journal, Engineering journal, Mathemetics journal, Physics journal, Chemistry journal, Computer Engineering, Computer Science journal, how to submit your paper, peer reviw journal, indexed journal, reserach and review articles, engineering journal, www.ijerd.com, research journals,
yahoo journals, bing journals, International Journal of Engineering Research and Development, google journals, hard copy of journal
In this paper, we discussed about LTE system throughput calculation for both TDD and FDD system.
3GPP LTE technology support both TDD and FDD multiplexing. The paper describes all the factors which affect the throughput like Bandwidth, Modulation, UE category and mulplexing. It also describes how we get throughput 300Mbps in DL and 75Mbps in UL and what are assumptions taken to calculate the same.
Paper describes the steps and formulae to calculate the throughput for FDD system for TDD Config 1 and Config 2.
The throughput calculations shown in this paper is theoretical and limited by the assumptions taken to calculate for calculations
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.
Motivation and results coverage enhancment for 3GPP NR Rel.17 Eiko Seidel
In this paper we would like to emphasize once again the need to look at large coverage scenarios for 5G NR and express our support for the creation of a Rel.17 work item. Furthermore, we provide first system-level simulation results to further motivate work on coverage enhancements and prove our commitment to contribute to a study item in the working groups in Rel.17 with independent performance evaluation.
COMPARISON OF BIT ERROR RATE PERFORMANCE OF VARIOUS DIGITAL MODULATION SCHEME...ijasa
Digital modulation increases information capacity, data security, and system availability while maintaining high communication quality. As a result, digital modulation techniques are in higher demand than analog modulation techniques due to their ability to transmit larger amounts of data. Amplitude Shift Keying (ASK), Frequency Shift Keying (FSK), Phase Shift Keying (PSK), Differential Phase Shift Keying (DPSK), and Quadrature Amplitude Modulation (QAM) are critical components of current communications systems development, particularly for broadband wireless communications. In this paper, the comparison of bit error rate performance of different modulation schemes (BPSK, QPSK, and16-QAM) and various equalization techniques such as constant modulus algorithm (CMA) and maximum likelihood sequence estimate (MLSE) for the AWGN and Rayleigh fading channels is analyzed using Simulink. BPSK outperforms QPSK and 16-QAM when compared to the other two digital modulation schemes. Among the three digital modulation schemes, BPSK is showing better performance as compared to QPSK and 16- QAM
Performance Analysis of Wireless Networks With MDQOSIJERA Editor
In Wireless/Mobile networks various kinds of encoding schemes were used for transmission of data over a bandwidth. The desired quality and generated traffic varies with the requirement with this bandwidth. A generic video telephony may require more than 40 kbps whereas a low motion video telephony may require about 25 kbps for data transmission. From the designing point of view these requirements demands for an alternative resource planning, especially for bandwidth allocation in wireless networks. In wireless network where bandwidth is a scare resource, the system may need to block incoming user if all of the bandwidth has been used to provide highest quality of service to existing users. However this bandwidth resource planning may be unacceptable for larger application. A degradable approach to multiple users can be made on bandwidth allocation to reduce the blocking probability without degrading the quality of service to existing users.
This work aims towards a realization of a wireless/mobile network using W-CDMA multi access technique supporting multilevel quality of services. The bandwidth allocation to multiple users is adjusted dynamically according to the required network condition so as to increase bandwidth utilization. The work analyze the performance deriving the degradation period ratio, mean degradation time and degradation state for the implemented wireless network.The proposed work is aim to implement on Matlab tool for its functional verification considering various mobility patterns
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology
Life cycle assessment and simulation enablers of sustainable product designeSAT Publishing House
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology.
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology.
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology.
A 2.4 ghz cmos lna input matching design using resistive feedback topology in...eSAT Publishing House
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology.
Determinants of global competitiveness on industrial performance an applicati...eSAT Publishing House
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology.
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology.
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology.
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology.
An analysis of raw materials for concretes as metal sheets for solar radiatio...eSAT Publishing House
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology.
Survey on sensor protocol for information via negotiation (spin) protocoleSAT Publishing House
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology
Production and characterization of nano copper powder using electric explosio...eSAT Publishing House
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology
Contribution to the valorization of moroccan wood in industry of laminated wo...eSAT Publishing House
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology
International Journal of Engineering and Science Invention (IJESI) is an international journal intended for professionals and researchers in all fields of computer science and electronics. IJESI publishes research articles and reviews within the whole field Engineering Science and Technology, new teaching methods, assessment, validation and the impact of new technologies and it will continue to provide information on the latest trends and developments in this ever-expanding subject. The publications of papers are selected through double peer reviewed to ensure originality, relevance, and readability. The articles published in our journal can be accessed online.
DYNAMIC OPTIMIZATION OF OVERLAPAND- ADD LENGTH OVER MBOFDM SYSTEM BASED ON SN...cscpconf
An important role performed by Zero Padding (ZP) in multi-band OFDM (MB-OFDM) System.
This role show for low-complexity in résistance against multipath interference by reducing
inter-carrier interference (ICI) and eliminating the inter-symbol interference (ISI) Also, zeropadded
suffix can be used to eliminate ripples in the power spectral density in order to conform
to FCC requirements.
At the receiver of MB-OFDM system needs to use of a technique called as overlap-and-add
(OLA). Which maintain the circular convolution property and take the multipath energy of the
channel.
In this paper, we proposed a method of performing overlap-and-add length for zero padded
suffixes. Then, we studied the effect of this method, dynamic optimization of overlap-and-add
(OLA) equalization, on the performance of MBOFDM system on Bit Error Rate (BER) with
AWGN channel and Saleh-Valenzuela (S-V) Multipath channel Model.
In the dynamic optimization OLA, the Length of ZP depends on length of channel impulse
response (CIR). These measures, based on SNR, insert the ZP according to the measurement.
Dynamic optimization of length of ZP improves the Performance of MBOFDM system. In fact
we developed a technique to select the length of ZP as function of SNR and CIR
estimate(repetition). In our simulation this technique improve to 3 dB at BER=10-2 with a
multipath channels CM4.
An important role performed by Zero Padding (ZP) in multi-band OFDM (MB-OFDM) System.
This role show for low-complexity in résistance against multipath interference by reducing
inter-carrier interference (ICI) and eliminating the inter-symbol interference (ISI) Also, zeropadded
suffix can be used to eliminate ripples in the power spectral density in order to conform
to FCC requirements.
At the receiver of MB-OFDM system needs to use of a technique called as overlap-and-add
(OLA). Which maintain the circular convolution property and take the multipath energy of the
channel.
In this paper, we proposed a method of performing overlap-and-add length for zero padded
suffixes. Then, we studied the effect of this method, dynamic optimization of overlap-and-add
(OLA) equalization, on the performance of MBOFDM system on Bit Error Rate (BER) with
AWGN channel and Saleh-Valenzuela (S-V) Multipath channel Model.
In the dynamic optimization OLA, the Length of ZP depends on length of channel impulse
response (CIR). These measures, based on SNR, insert the ZP according to the measurement.
Dynamic optimization of length of ZP improves the Performance of MBOFDM system. In fact
we developed a technique to select the length of ZP as function of SNR and CIR
estimate(repetition). In our simulation this technique improve to 3 dB at BER=10-2 with a
multipath channels CM4.
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.
Performance Improvement of IEEE 802.22 WRAN Physical LayerIOSR Journals
The spectrum available for the wireless services is limited, the increased demand of wireless
application has put a lot of limitations on the utilization of available radio spectrum. For the efficient spectrum
utilization for wireless application IEEE 802.22 standard i.e. WRAN (Wireless Regional Area Network) is
developed which is based on cognitive radio technique that senses the free available spectrum. It allows sharing
of geographically unused channels allocated to the TV Broadcast Service, without interference.
In this paper we are evaluating the performance of WRAN over physical layer with QPSK, 16-QAM
and 64-QAM modulation with Convolution coding with code rate of 1/2, 2/3, 3/4, 5/6 and obtaining the BER
curves for rician channel. Simulation is performed in MATLAB
Performance Improvement of IEEE 802.22 WRAN Physical LayerIOSR Journals
Abstract: The spectrum available for the wireless services is limited, the increased demand of wireless application has put a lot of limitations on the utilization of available radio spectrum. For the efficient spectrum utilization for wireless application IEEE 802.22 standard i.e. WRAN (Wireless Regional Area Network) is developed which is based on cognitive radio technique that senses the free available spectrum. It allows sharing of geographically unused channels allocated to the TV Broadcast Service, without interference. In this paper we are evaluating the performance of WRAN over physical layer with QPSK, 16-QAM and 64-QAM modulation with Convolution coding with code rate of 1/2, 2/3, 3/4, 5/6 and obtaining the BER curves for rician channel. Simulation is performed in MATLAB. Keywords - CC, CP, CR, OFDMA, PHY Layer, WRAN
Performance Improvement of IEEE 802.22 WRAN Physical LayerIOSR Journals
Abstract: The spectrum available for the wireless services is limited, the increased demand of wireless
application has put a lot of limitations on the utilization of available radio spectrum. For the efficient spectrum
utilization for wireless application IEEE 802.22 standard i.e. WRAN (Wireless Regional Area Network) is
developed which is based on cognitive radio technique that senses the free available spectrum. It allows sharing
of geographically unused channels allocated to the TV Broadcast Service, without interference.
In this paper we are evaluating the performance of WRAN over physical layer with QPSK, 16-QAM
and 64-QAM modulation with Convolution coding with code rate of 1/2, 2/3, 3/4, 5/6 and obtaining the BER
curves for rician channel. Simulation is performed in MATLAB.
Keywords - CC, CP, CR, OFDMA, PHY Layer, WRAN
DYNAMIC OPTIMIZATION OF OVERLAP-AND-ADD LENGTH OVER MIMO MBOFDM SYSTEM BASED ...ijwmn
An important role performed by Zero Padding (ZP) in multi-band OFDM (MB-OFDM) System. This role
show for low-complexity in résistance against multipath interference by reducing inter-carrier interference
(ICI) and eliminating the inter-symbol interference (ISI) Also, zero-padded suffix can be used to eliminate
ripples in the power spectral density in order to conform to FCC requirements. At the receiver of MB-OFDM system needs to use of a technique called as overlap-and-add (OLA). Which maintain the circular convolution property and take the multipath energy of the channel.In this paper, we proposed a method of performing overlap-and-add length for zero padded suffixes. Then,we studied the effect of this method, dynamic optimization of overlap-and-add (OLA) equalization, on the performance of MIMO MBOFDM system on Bit Error Rate (BER) with AWGN channel and SalehValenzuela (S-V) Multipath channel Model.In the dynamic optimization OLA, the Length of ZP depends on length of channel impulse response (CIR).
These measures, based on SNR, insert the ZP according to the measurement.Dynamic optimization of length of ZP improves the Performance of MIMO MBOFDM system. In fact wedeveloped a technique to select the length of ZP as function of SNR and CIR estimate. In our simulation
this technique improve to 0.6 dB at BER=10-2 with a multipath channels CM4
Performance Comparison of Multi-Carrier CDMA Using QPSK and BPSK ModulationIOSR Journals
Abstract: MC-CDMA (Multi Carrier Code Division Multiple Access) plays an important role in modern wireless communications. Modern communication required an efficient spectrum usage and capacity and throughput.MC-CDMA provided the solution of these problems. MIMO refers to links with multiple antennas at the transmitter and receiver side. CDMA systems combined with multiple antennas is a promising technique, beyond 3G and 4G wireless communications. MIMO provides spatial diversity, which mitigates the fading. The usage of multiple antennas can significantly improve the performance of wireless communication system. This work also derives simulation through MATLAB of average bit error rate verses bit energy to noise ratio of multicarrier code division multiple access over Rayleigh channel using QPSK and BPSK modulation additive white Gaussian noise. Keywords: AWGN,BER,MC-CDMA, QPSK Modulation, Rayleigh Channel.
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
International Journal of 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.
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Improving quality of service using ofdm technique for 4 th generation network
1. IJRET: International Journal of Research in Engineering and Technology ISSN: 2319-1163
__________________________________________________________________________________________
Volume: 01 Issue: 02 | Oct-2012, Available @ http://www.ijret.org 125
IMPROVING QUALITY OF SERVICE USING OFDM TECHNIQUE
FOR 4TH GENERATION NETWORK
P.Sravan Kumar Reddy1
, P.Suhail Parvaze2
1 Student (M.Tech), ECE Department, QUBA College of Engineering & Technology, A.P., India, Sra1reddy@email.com
2 Assoc.Prof, ECE Department, QUBA College of Engineering & Technology, A.P., India, suhailsp@gmail.com
Abstract
The migration to 4G networks will bring a new level of expectation to wireless communications. As after digital wireless
revolution made mobile phones available for everyone, the higher speeds and packet delivery of 4G networks will make high quality
multimedia available everywhere. The key to achieving this higher level of service delivery is a new air interface, OFDM,
which is in turn enabled by the high level of performance. OFDM provides a robust signal that requires relatively little power
yet uses bandwidth very efficiently. Carriers will benefit from greater flexibility by using OFDM, since in the same spectrum they
will be able to offer more channels, including higher ‘bandwidth channels, with more types of services. Currently these systems
are still being defined and prototyped. Achieving higher data rates requires OFDM systems to make more efficient use of the
bandwidth than CDMA systems. One method of achieving this higher efficiency is through the use of higher order
modulation. In this paper we have compared two digital modulation techniques 32QAM and 64QAM used for digital transmission
of data. Our main objective to develop this configuration is to compare the performance of each modulation techniques.
Comparison is done by Bit Error Rate analysis of both modulation techniques. We have developed existing configurations and
improved them with high quality senders and receivers using MATLAB technology. In this paper we have also considered how
OFDM can improve the real time video streaming over the wireless network. We have considered the problem of multiuser
video streaming over OFDM. OFDM is a multi carrier modulation. The growing interest in Multicarrier Transmission by
researchers and product developers motivated us to propose this topic for a special issue of Wireless Video transmission and
Communications.
Index Terms: QAM’ Quadrature Amplitude Modulation, OFDM' Orthogonal Frequency Division Multiplexing, QoS’
Quality of service
-----------------------------------------------------------------------***-----------------------------------------------------------------------
1. INTRODUCTION
In OFDM, usable bandwidth is divided into a large number
of smaller bandwidths that are mathematically orthogonal using
fast Fourier transforms (FFTs). Reconstruction of the band is
performed by the inverse fast Fourier transform (IFFT).
One beneficial feature of this technique is the ease of adaptation
to different bandwidths. The smaller bandwidth unit can
remain fixed, even as the total bandwidth utilization is
changed. For example, a 10'MHz bandwidth allocation may
be divided into 1,024 smaller bands, whereas a 5'MHz
allocation would be divided into 512 smaller bands. These
smaller bands are referred to as subcarriers and are typically
on the order of 10 kHz. One challenge in today’s wireless
systems is an effect called 'multipath.' Multipath results from
reflections between a transmitter and receiver whereby the
reflections arrive at the receiver at different times. The time
span separating the reflection is referred to as delay spread. This
type of interference tends to be problematic when the delay
spread is on the order of the transmitted symbol time.
Typical delay spreads are microseconds in length, which are
close to CDMA symbol times. OFDMA symbol times tend to
be on the order of 100 microseconds, making multipath less
of a problem. In order to mitigate the effect of multipath, a
guard band of about 10 microseconds, called the cyclic
prefix, is inserted after each symbol. Achieving higher data
rates requires OFDM systems to make more efficient use
of the bandwidth than CDMA systems. The number of bits per
unit hertz is referred to as the spectral efficiency. One method
of achieving this higher efficiency is through the use of
higher order modulation. Modulation refers to the number of
bits that each subcarrier transmits. The design consideration of
OFDM scheme has been discussed in past [1].
2. RELATED WORK
In the QAM digital modulation techniques, the Amplitude
and Phase are the main parameters on which work is
carried out. In our configuration we have taken AWGN
channel (Gaussian Channel) where white Gaussian noise is
added to the signal and that noisy signal is sent towards the
receiver that is recovered with appropriate demodulator and
decoders. The Wireless LAN standard, IEEE 802.11b, uses a
variety of different QAMs depending on the data' rate required.
QAM is employed, but has to be coupled with
complementary code Modulation. The higher’ speed wireless
LANstandard, IEEE 802.11g has eight data rates: 6, 9, 12, 18,
24, 36, 48 and 54 Mbit/s. The 6 and 9 Mbit/s modes use
2. IJRET: International Journal of Research in Engineering and Technology ISSN: 2319-1163
__________________________________________________________________________________________
Volume: 01 Issue: 02 | Oct-2012, Available @ http://www.ijret.org 126
OFDM modulation where each sub’carrier is 8 QAM
modulated. Many parameters for managing basic QoS for
next generation network have been discussed in past [8] [10].
Multi'Carrier Modulation (MCM) is the principle of transmitting
data by dividing the stream into several parallel bit streams, each
of which has a much lower bit rate, and by using these sub
streams to modulate several carriers. OFDM abandoned the use
of steep band pass filters that completely separated the
spectrum of individual subcarriers, as it was common
practice in older Frequency Division Multiplex (FDMA)
systems. OFDM time’ domain waveforms are chosen such
that mutual orthogonality is ensured even though subcarrier
spectra may overlap. It appeared that such waveforms can
be generated using a Fast Fourier Transform at the transmitter
and receiver
3.ORTHOGONAL FREQUENCY DIVESION
MULTIPLEXING (OFDM)
OFDM is a combination technique between modulation and
multiplexing. Modulation is a mapping of the information
on changes in the carrier phase, frequency or amplitude or
their combination. Meanwhile, multiplexing is a method of
sharing a bandwidth with other independent data channel. In
multiplexing, independent signals from different sources are
sharing the channel spectrum. In OFDM, multiplexing is
applied to independent signals but these independent signals are
a sub'set of the one main signal. In OFDM the signal itself is
first split into independent channels, modulated by data and
then re'multiplexed to create the OFDM carrier. The
multicarrier transmission technique uses the discrete Fourier
transform. By using a DFT, the whole bandwidth will be split
into N sub channels. As a result, a high data stream will
be transformed into N low rate streams, which are
transmitted over different sub'channels. OFDM symbols,
which contain several modulation symbols, are formed as
linear combinations of mutually orthogonal complex
exponentials of finite duration [12]. The splitting of high rate
data stream into a number of lower rate streams results in the
increase of symbol duration. Mean while a lower rate
parallel subcarriers reduces the relative amount of dispersion
in time caused by multipath delay spread. Therefore OFDM
is an advanced modulation technique which is suitable for
high'speed data transmission due to its advantages in dealing
with the multipath propagation problem and bandwidth
efficiency. Fig: 1 show the spectrum of individual sub
channel and the spectrum of the entire OFDM signal
respectively. It can be noticed that there is no crosstalk from
other channels at the center frequency of each subcarrier. As
Fig: 2 shows the parallel transmission of data over multiple
simultaneous carriers makes the OFDM system to be more
robust against frequency selective fading or narrowband
interference; some subcarriers may be degraded. a circle. With
four phases, QAM can encode 32 bits per symbol, with Gray
coding to minimize the BER — twice the rate of 8QAM.
Analysis shows that this may be used either to double the data
rate
Fig 1: Frequency Plot for single carrier signal
Fig 2 : Frequency Plot for Multi carrier signal
Like all modulation schemes, QAM conveys data by changing
some aspect of a carrier signal, or the carrier wave, (usually a
sinusoid) in response to a data signal. In the case of QAM, the
amplitude of two waves, 90° out-of-phase with each other (in
quadrature) are changed (modulated or keyed) to represent the
data signal. Amplitude modulating two carriers in quadrature
can be equivalently viewed as both amplitude modulating and
phase modulating a single carrier.
3.1 QAM MODULATION
A method for encoding digital data in an analog signal in which
each combination of phase and amplitude represents one of
sixteen four bit patterns. This is required for fax transmission at
9600 bits per second.Like all modulation schemes, QAM
conveys data by changing some aspect of a carrier signal, or the
carrier wave, (usually a sinusoid) in response to a data signal.
In the case of QAM, the amplitude of two waves, 90° out-of-
phase with each other (in quadrature) are changed (modulated
or keyed) to represent the data signal.
3. IJRET: International Journal of Research in Engineering and Technology ISSN: 2319-1163
__________________________________________________________________________________________
Volume: 01 Issue: 02 | Oct-2012, Available @ http://www.ijret.org 127
Fig 3: 4G_OFDM_32_QAM Technology
Fig 4: Input signal 10 Frames generated by source
Fig 5: Scatter plot of OFDM_32_QAM For given source
4. IJRET: International Journal of Research in Engineering and Technology ISSN: 2319-1163
__________________________________________________________________________________________
Volume: 01 Issue: 02 | Oct-2012, Available @ http://www.ijret.org 128
Fig 6: 4G_OFDM_64_QAM Technology
Fig 7: Input signal 10 Frames generated by source
5. IJRET: International Journal of Research in Engineering and Technology ISSN: 2319-1163
__________________________________________________________________________________________
Volume: 01 Issue: 02 | Oct-2012, Available @ http://www.ijret.org 129
Amplitude modulating two carriers in quadrature can be
equivalently viewed as both amplitude modulating and phase
modulating a single carrier.
If data-rates beyond those offered by 8-PSK are required, it is
more usual to move to QAM since it achieves a greater
distance between adjacent points in the I-Q plane by
distributing the points more evenly. The complicating factor is
that the points are no longer all the same amplitude and so the
demodulator must now correctly detect both phase and
amplitude, rather than just phase. 64-QAM and 256-QAM are
often used in digital cable television and cable modem
applications. In the United States, 64-QAM and 256-QAM are
the mandated modulation schemes for digital cable (see QAM
tuner) as standardised by the SCTE in the standard
ANSI/SCTE 07 2000. Note that many marketing people will
refer to these as QAM-64 and QAM-256. In the UK, 16-QAM
and 64-QAM are currently used for digital terrestrial
television and 256-QAM is planned for Freeview-HD.
Communication systems designed to achieve very high levels
of spectral efficiency usually employ very dense QAM
constellations. For example current Homeplug AV2 500-Mbit
power line Ethernet devices use 1024-QAM and 4096-QAM
modulation, as well as future devices using ITU-T G.hn
standard for networking over existing home wiring (coaxial
cable, phone lines and power lines); 4096-QAM provides 12
bits/symbol. Another example is VDSL2 technology for
copper twisted pairs, whose constellation size goes up to
32768 points.
4. METHODOLOGY AND CHANNEL MODEL
CONFIGURATION
As mentioned in the introduction, in this paper we have
compared the configuration of 32QAM and 64QAM
techniques with OFDM technique. Methodology steps of the
configuration are as follows:'
1.Data Source a. Select the random integer (in the range of 0
to 32 and 0 to 64).
b. Select the initial seed point (in the configuration we
have taken 12345 as seed point)
c.Select the sample rate (192 samples/ frame in the
configuration)
d.Convert the integer into bits (2bits per integer)
2. Modulation (32QAM/64QAM)
a. Apply the Modulation technique on generated
random data source. Output of the modulator
baseband is complex type.
b.Get the real part of the modulated data.
3.Apply OFDM modulation
a. Divide the carrier into subcarriers (10 sub
carriers in the configuration)
b.Add cyclic redundancy for error detections and
correction
c.Apply IFFT (Inverse Fast Fourier Transform) and take
a conjugate symmetry to take real part of the
transformed signal.
4.Add Noise to the carriers
a. Pass the signal over AWGN signal, this can be
done by specifying Signal to Noise Ratio (SNR=15
in the configuration)
5. Apply OFDM demodulation
a. Remove the cyclic redundancy
b. Apply serial FFT (Fast Fourier Transform) to the signal
as well as EML FFT algorithm
c. Convert the samples into frame
6. Demodulation (32QAM/64QAM)
a. Apply the demodulation technique on the output of
OFDM.
b. Convert the integer into bits
5. PERFORMANCE EVALUATION
In the presented model we have used Bit loss and packet loss
evaluating the performance of both the modulation techniques
with OFDM. We used MATLAB simulator to implement
above model. Simulation shows that the signal is passed
through noisy channel that is AWGN channel after OFDM
modulation. Noise immunity can be altered in the signal and
BER can be analyzed with different noise immunity. From the
simulation results we observed that 64QAM modulation is
more prone to errors while transmitting signal through noisy
channel than 32QAM . Many performance evaluation of
OFDM based system has been done earlier [2] [5].In our
configuration 10 frames are transmitted, and each frame
contains 192 bits, so total numbers of bits are transmitted
as1920.Table 1. shows comparative analysis between two
modulation scheme using OFDM techniques. Result shows
that 32 QAM scheme having minimum bit loss and packet loss
so the 32QAM modulation scheme can be efficiently used for
4G networks
Table 1: Comparative Analysis
Modulation Total Bits Bit Loss Packet loss
32 QAM 1920 65 0.03385
64QAM 1920 80 0.04167
6. REAL TIME VIDEO STREAMING
WITH OFDM
Video streaming has become a very popular application
in communications as achievable data rates have improved
dramatically. When real time video is transferred over the
wireless network or real time video is displayed on the
cellular phones then there are two issues that must be resolved
6. IJRET: International Journal of Research in Engineering and Technology ISSN: 2319-1163
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Volume: 01 Issue: 02 | Oct-2012, Available @ http://www.ijret.org 130
6.1 Bandwidth Requirement:
Since the video transfer requires high data rate and high
bandwidth Video requires large amount of data storage
that is transferred over the network with limited bandwidth.
This can be done by compressing the video before
transmission.
6.2 Modulation:
Secondly very important issue is modulation of bits that
are transferred. Because of the obstacles in the medium
of the wireless data transmission the signal level can result in
the loss of important information which must be perceived by
the receiver. Streaming video is content sent in
compressed form over the Internet and displayed by the
viewer in real time. With streaming video or streaming
media, a Web user does not have to wait to download a
file to play it. Instead, the media is sent in a continuous
stream of data and is played as it arrives. In our paper we have
configured Orthogonal Frequency Division Multiplexing
using MATLAB and SIMULINK. The main idea behind
this is that divide the data to be sent into different blocks and
each block is modulated with different sub carrier, and all the
sub carries are orthogonal to each other. Results show a
considerable amount of improvement in quality of video
signals using OFDM techniques.
CONCLUSIONS
The demand for increased channel capacity in wireless and
mobile communications has been rapidly increasing
worldwide. The driving force behind the need to satisfy
this requirement is the explosion in mobile telephone,
Internet and multimedia services coupled with a limited
radio spectrum. The BER is an important parameter in
mobile communication for quality measurement of
recovered data. In this paper we have presented a method
to evaluate the performance of OFDM system with
32QAM and 64QAM. The comparison given in Table 1
and it shows the bit loss and packet loss of each modulation
scheme. By comparison, it is observed that 32QAM
modulation techniques having less packet loss and bit loss
than 64QAM technique which enhance quality of
experience to the user. Results have been obtained which
is useful for channel parameter estimation and can be
efficiently used for 4G networks.
REFERENCES
[1] Angela Dnufexi, Simon Armour, Andrew NU and
Mark Beach ―Design considerations and initial
physical layer cellular network‖ IEEE 2002 pp 192'196
[2] A. Dowler, A. Doufexi and A. Nix, ―Performance
Evaluation of Channel Estimation Techniques for a
Mobile Fourth Generation Wide Area OFDM System,‖
Vehicular Technology Conference, 2002.
Proceedings.VTC 2002 Fall, 2002 IEEE 56th, vol.4, pp.
2036 – 2040, 2002.
[3] Ahmed, A.B.; Osman, W.E.; Rahman, T.A.;
Orthogonal ―Frequency Division Multiple Acces System
Analysis Using Bit Error Rate Next Generation Mobile
Applications, Services and Technologies‖ 2009.
NGMAST '09. Third International Conference on
Publication Year: 2009 , Page(s): 211 ' 214
[4] Bit Error Rate: Fundamental Concepts and
Measurement Issues by Gary Breed.
[5] Boudali Ouarzazi, Marion Berbineau, Iyad Dayoub,
Atika Menhaj'Rivenq,‖ Channel estimation of OFDM
system for high data rate communications on mobile
environments‖ IEEE Proceeding 2009 pp 425'429
[6] Gerhard Wunder, Thomas Michel, Chan Zhou,
―Delay' Limited Transmission in OFDM Systems:
Performance Bounds and Impact of System
Parameters‖ IEEE Transactions on wireless
communications, VOL. 8, NO. 7, JULY 2009 pp
3747'3757
[7] I. Korn, ―Performance of Digital Communications
Schemes with Multidimensional Signals in Gaussian
Noise,‖ IEEE Trans. Commun., vol. 44, no. 9, September
1996.
[8] Kyung'chul Cho, Young'Chang Kang, Sun'hyung Kim
―Performance Analysis of the DQPSK'OFDM System
with Equalizer for the Wireless Multimedia
Communication‖ Second International Conference on
Future Generation Communication and Networking 2008
pp 78'81
[9] Neill Weilkinson ―Next Generation Network
Services Technologies and Strategies‖ john willey
and sons ltd pp 167'170.
[10] Nor K. NoordinI, Borhanuddin M. AliI, S. S.
Jamuarl and Mahamod B. Ismai12 Transmit
Optimization for MIMO' OFDM With
Delay'Constrained and No'Delay'Constrained Traffic
IEEE transactions on signal processing, VOL. 54,
NO. 8, AUGUST 2006
BIOGRAPHIES:
P. Sravan Kumar Reddy had Received
B.Tech in Electronics and Communication
Engineering (ECE) from JNTU,
Hyderabad, India in 2007. He is persuing
his M.Tech in Quba college of
engineering and technology, JNTUA,
Anantapur, India
P.Suhail Parvaze is working s an
Associate Professor in QUBA College of
engineering and Technology, Nellore. He
has 7 years teaching experience both at UG
and PG level and 1 year industrial
experience