This paper presents a new MDC scheme for robust wireless data communications. The soft detection making of the MDC scheme utilises the statistical received data error obtained from channel decoding. The coded bit stream in the system is protected using either the Reed Solomon (RS) or Low Density Parity Check Codes (LDPC) channel coding scheme. Simulation results show that this system has some significant performance improvements over the single description or single channel transmission systems in terms of symbol error rate and peak signal-to-noise ratio PSNR. The system with RS codes is 2 to 5 dB better than single description. The system with LDPC channel codes is 6 to10 dB better than the single description.
Dcf learn and performance analysis of 802.11 b wireless networkIJCNCJournal
Though WLAN wireless network has been widely deployed as the main split-flow deployment of the
communication network, little study emphasizes its performance as WLAN protocols were only designed for
the public communicating conveniently with each other. Actually that too much wireless access points
assembling together will cause self-interference to the whole WLAN network. This paper investigates the
distributed coordination function (DCF) learn and the performance study of 802.11b networks. Firstly, our
study illustrates the performance of its MAC layer and its fairness issues related to DCF. Next we propose
the details which should be paid attention to in deploying network services. Then, performance analyses
are evaluated by simulation and real test for a dense wireless network. Our main goal is to give proposals
to network operators how to design a WLAN network more standardized and orderly.
Spatialization Parameter Estimation in MDCT Domain for Stereo AudioCSCJournals
For representing multi-channel audio at low bit rate parametric coding techniques are used in many audio coding standards. An MDCT domain parametric stereo coding algorithm which represents the stereo channels as the linear combination of the ‘sum’ channel derived from the stereo channels and a reverberated channel generated from the ‘sum ’channel has been reported in literature. This model is inefficient in capturing the stereo image since only four parameters per sub-band is used as spatialization parameters. In this work we improve this MDCT domain parametric coder with an augmented parameter extraction scheme using an additional reverberated channel. We further modify the scheme by using orthogonalized de-correlated channels for analysis and synthesis of parametric stereo. A synthesis scheme with perceptually scaled parameter set is also introduced. Finally we present, subjective evaluation of the different parametric stereo schemes using MUSHRA test and the increased the perceptual audio quality of the synthesized signals are evident from these test results.
Performance analysis of transmission of 5 users based on model b using gf (5)...csandit
We present transmission of five users with 5 WDM × 4 TDM × 5 CODE channel on 3D
OCDMA system based on Model B using GF (5) with varying receiver attenuation at 1Gbps, 2
Gbps, 5Gbps and 10Gbps data rates on OPTSIM.
PERFORMANCE OF WIMAX PHYSICAL LAYER WITH VARIATIONS IN CHANNEL CODING AND DIG...ijistjournal
The aim of this paper is to analyze the bit error rate (BER) performance of WiMAX physical layer with the implementation of different concatenated channel coding schemes under QAM and 16QAM digital modulations over realistic channel conditions (i.e. noise and multipath fading). In concatenated channel coding, the WiMAX system incorporates CRC-CC (Cyclic Redundancy Check and Convolutional) or RSCC (Reed-Solomon and Convolutional) encoder over an additative white gaussian noise (AWGN) and other multipath fading (Raleigh and Rician) channels. A segment of synthetic data is used for the analysis. Computer simulation results based on BER and signal to noise ratio (SNR) demonstrate that the performance of concatenated CRC-CC coded WiMAX system under QAM modulation is better as compared to RS-CC coded system over noisy and fading environments.
In this paper, low linear architectures for analyzing the first two maximum or minimum values are of paramount importance in several uses, including iterative decoders. The min-sum giving out step is to that it produces only two diverse output magnitude values irrespective of the number of incoming bit-to check communication. These new micro-architecture structures would utilize the minimum number of comparators by exploiting the concept of survivors in the search. These would result in reduced number of comparisons and consequently reduced energy use. Multipliers are complex units and play an important role in finding the overall area, speed and power consumption of digital designs. By using the multiplier we can minimize the parameters like latency, complexity and power consumption. The decoding algorithms we propose generalize and unify the decoding schemes originally presented the product codes and those of low-density parity-check codes.
Chaos Encryption and Coding for Image Transmission over Noisy Channelsiosrjce
IOSR Journal of Computer Engineering (IOSR-JCE) is a double blind peer reviewed International Journal that provides rapid publication (within a month) of articles in all areas of computer engineering and its applications. The journal welcomes publications of high quality papers on theoretical developments and practical applications in computer technology. Original research papers, state-of-the-art reviews, and high quality technical notes are invited for publications.
Compression is playing a vital role in data transfer. Hence, Digital camera uses JPEG standard to compress the captured image. Hence, it reduces data storage requirements. Here, we proposed FPGA based JPEG encoder. The processing system is coupled with DCT and then it is quantized and then it is prepared for entropy coding to form a JPEG encoder
Dcf learn and performance analysis of 802.11 b wireless networkIJCNCJournal
Though WLAN wireless network has been widely deployed as the main split-flow deployment of the
communication network, little study emphasizes its performance as WLAN protocols were only designed for
the public communicating conveniently with each other. Actually that too much wireless access points
assembling together will cause self-interference to the whole WLAN network. This paper investigates the
distributed coordination function (DCF) learn and the performance study of 802.11b networks. Firstly, our
study illustrates the performance of its MAC layer and its fairness issues related to DCF. Next we propose
the details which should be paid attention to in deploying network services. Then, performance analyses
are evaluated by simulation and real test for a dense wireless network. Our main goal is to give proposals
to network operators how to design a WLAN network more standardized and orderly.
Spatialization Parameter Estimation in MDCT Domain for Stereo AudioCSCJournals
For representing multi-channel audio at low bit rate parametric coding techniques are used in many audio coding standards. An MDCT domain parametric stereo coding algorithm which represents the stereo channels as the linear combination of the ‘sum’ channel derived from the stereo channels and a reverberated channel generated from the ‘sum ’channel has been reported in literature. This model is inefficient in capturing the stereo image since only four parameters per sub-band is used as spatialization parameters. In this work we improve this MDCT domain parametric coder with an augmented parameter extraction scheme using an additional reverberated channel. We further modify the scheme by using orthogonalized de-correlated channels for analysis and synthesis of parametric stereo. A synthesis scheme with perceptually scaled parameter set is also introduced. Finally we present, subjective evaluation of the different parametric stereo schemes using MUSHRA test and the increased the perceptual audio quality of the synthesized signals are evident from these test results.
Performance analysis of transmission of 5 users based on model b using gf (5)...csandit
We present transmission of five users with 5 WDM × 4 TDM × 5 CODE channel on 3D
OCDMA system based on Model B using GF (5) with varying receiver attenuation at 1Gbps, 2
Gbps, 5Gbps and 10Gbps data rates on OPTSIM.
PERFORMANCE OF WIMAX PHYSICAL LAYER WITH VARIATIONS IN CHANNEL CODING AND DIG...ijistjournal
The aim of this paper is to analyze the bit error rate (BER) performance of WiMAX physical layer with the implementation of different concatenated channel coding schemes under QAM and 16QAM digital modulations over realistic channel conditions (i.e. noise and multipath fading). In concatenated channel coding, the WiMAX system incorporates CRC-CC (Cyclic Redundancy Check and Convolutional) or RSCC (Reed-Solomon and Convolutional) encoder over an additative white gaussian noise (AWGN) and other multipath fading (Raleigh and Rician) channels. A segment of synthetic data is used for the analysis. Computer simulation results based on BER and signal to noise ratio (SNR) demonstrate that the performance of concatenated CRC-CC coded WiMAX system under QAM modulation is better as compared to RS-CC coded system over noisy and fading environments.
In this paper, low linear architectures for analyzing the first two maximum or minimum values are of paramount importance in several uses, including iterative decoders. The min-sum giving out step is to that it produces only two diverse output magnitude values irrespective of the number of incoming bit-to check communication. These new micro-architecture structures would utilize the minimum number of comparators by exploiting the concept of survivors in the search. These would result in reduced number of comparisons and consequently reduced energy use. Multipliers are complex units and play an important role in finding the overall area, speed and power consumption of digital designs. By using the multiplier we can minimize the parameters like latency, complexity and power consumption. The decoding algorithms we propose generalize and unify the decoding schemes originally presented the product codes and those of low-density parity-check codes.
Chaos Encryption and Coding for Image Transmission over Noisy Channelsiosrjce
IOSR Journal of Computer Engineering (IOSR-JCE) is a double blind peer reviewed International Journal that provides rapid publication (within a month) of articles in all areas of computer engineering and its applications. The journal welcomes publications of high quality papers on theoretical developments and practical applications in computer technology. Original research papers, state-of-the-art reviews, and high quality technical notes are invited for publications.
Compression is playing a vital role in data transfer. Hence, Digital camera uses JPEG standard to compress the captured image. Hence, it reduces data storage requirements. Here, we proposed FPGA based JPEG encoder. The processing system is coupled with DCT and then it is quantized and then it is prepared for entropy coding to form a JPEG encoder
Rate Distortion Performance for Joint Source Channel Coding of JPEG image Ove...CSCJournals
This paper presents the rate distortion behavior of Joint Source Channel Coding (JSCC) scheme for still image transmission. The focus is on DCT based Source coding JPEG, Rate Compatible Punctured Convolution codes (RCPC) for transmission over Additive White Gaussian Noise (AWGN) channel under the constraint of fixed transmission bandwidth. Information transmission has a tradeoff between compression ratio and received quality of image. The compressed stream is more susceptible to channel errors, thus error control coding techniques are used along with images to minimize the effect of channel errors. But there is a clear tradeoff between channel coding redundancies versus source quality with constant channel bit rate. This paper proposes JSCC scheme based on Unequal Error Protection (UEP) for robust image transmission. With the conventional error control coding schemes that uses Equal Error Protection (EEP), all the information bits are equally protected. The use of the UEP schemes provides a varying amount of error protection according to the importance of the data. The received image quality can be improved using UEP compared to Equal Error Protection (EEP).
Hardware implementation of (63, 51) bch encoder and decoder for wban using lf...ijitjournal
Error Correcting Codes are required to have a reliable communication through a medium that has an
unacceptable bit error rate and low signal to noise ratio. In IEEE 802.15.6 2.4GHz Wireless Body Area
Network (WBAN), data gets corrupted during the transmission and reception due to noises and
interferences. Ultra low power operation is crucial to prolong the life of implantable devices. Hence simple
block codes like BCH (63, 51, 2) can be employed in the transceiver design of 802.15.6 Narrowband PHY.
In this paper, implementation of BCH (63, 51, t = 2) Encoder and Decoder using VHDL is discussed. The
incoming 51 bits are encoded into 63 bit code word using (63, 51) BCH encoder. It can detect and correct
up to 2 random errors. The design of an encoder is implemented using Linear Feed Back Shift Register
(LFSR) for polynomial division and the decoder design is based on syndrome calculator, inversion-less
Berlekamp-Massey algorithm (BMA) and Chien search algorithm. Synthesis and simulation were carried
out using Xilinx ISE 14.2 and ModelSim 10.1c. The codes are implemented over Virtex 4 FPGA device and
tested on DN8000K10PCIE Logic Emulation Board. To the best of our knowledge, it is the first time an
implementation of (63, 51) BCH encoder and decoder carried out.
Reliability Level List Based Iterative SISO Decoding Algorithm for Block Turb...TELKOMNIKA JOURNAL
An iterative Reliability Level List (RLL) based soft-input soft-output (SISO) decoding algorithm has been proposed for Block Turbo Codes (BTCs). The algorithm ingeniously adapts the RLL based decoding algorithm for the constituent block codes, which is a soft-input hard-output algorithm. The extrinsic information is calculated using the reliability of these hard-output decisions and is passed as soft-input to the iterative turbo decoding process. RLL based decoding of constituent codes estimate the optimal transmitted codeword through a directed minimal search. The proposed RLL based decoder for the constituent code replaces the Chase-2 based constituent decoder in the conventional SISO scheme. Simulation results show that the proposed algorithm has a clear advantage of performance improvement over conventional Chase-2 based SISO decoding scheme with reduced decoding latency at lower noise levels.
FPGA Implementation of Viterbi Decoder using Hybrid Trace Back and Register E...ijsrd.com
Error correction is an integral part of any communication system and for this purpose, the convolution codes are widely used as forward error correction codes. For decoding of convolution codes, at the receiver end Viterbi Decoder is being employed. The parameters of Viterbi algorithm can be changed to suit a specific application. The high speed and small area are two important design parameters in today’s wireless technology. In this paper, a high speed feed forward viterbi decoder has been designed using hybrid track back and register exchange architecture and embedded BRAM of target FPGA. The proposed viterbi decoder has been designed with Matlab, simulated with Xilinx ISE 8.1i Tool, synthesized with Xilinx Synthesis Tool (XST), and implemented on Xilinx Virtex4 based xc4vlx15 FPGA device. The results show that the proposed design can operate at an estimated frequency of 107.7 MHz by consuming considerably less resources on target device to provide cost effective solution for wireless applications.
Design, Analysis and Implementation of Modified Luby Transform CodeIOSR Journals
Abstract : Bit losses in erasure channels like computer networks are of great concern. The existing methods to combat bit losses are either inefficient or time consuming due to the retransmission protocols involved. Through this paper, we propose a Modified Luby Transform (MLT) coding scheme to efficiently transmit data over live computer networks. The MLT code can combat bit losses as well as eliminate the need for retransmission. The usability and reliability of the proposed MLT code is verified by testing it on a live computer network. Keywords : Erasure channel, Fountain Codes, Luby Transform Codes , Wired Networks, Wireless Networks
International Journal of Engineering Research and DevelopmentIJERD Editor
Electrical, Electronics and Computer Engineering,
Information Engineering and Technology,
Mechanical, Industrial and Manufacturing Engineering,
Automation and Mechatronics Engineering,
Material and Chemical Engineering,
Civil and Architecture Engineering,
Biotechnology and Bio Engineering,
Environmental Engineering,
Petroleum and Mining Engineering,
Marine and Agriculture engineering,
Aerospace Engineering.
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.
Joint Fixed Power Allocation and Partial Relay Selection Schemes for Cooperat...TELKOMNIKA JOURNAL
In the future wireless systems, non-orthogonal multiple-access (NOMA) with partial relay selection scheme is considered as developing research topic. In this paper, dual-hop relaying systems is deployed for NOMA, in which the signals are communicated with the assistance of decode-and-forward (DF) scheme. This paper presents exact expressions for outage probability over independent Rayleigh fading channels, and two partial relay selection schemes are provided. Using analytical result and Monte-Carlo method, we introduce forwarding strategy selection for fixed user allocation and exactness of derived formula is checked. The presented simulations confirm the the advantage of such proposed NOMA, and the effectiveness of the proposed forwarding strategy.
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.
Reduced Energy Min-Max Decoding Algorithm for Ldpc Code with Adder Correction...ijceronline
In this paper, high linear architectures for analysing the first two maximum or minimum values are of paramount importance in several uses, including iterative decoders. We proposed the adder and LDPC. The min-sum processing step that it gives only two different output magnitude values irrespective of the number of incoming bit-to check messages. These new micro-architecture layouts would employ the minimum number of comparators by exploiting the concept of survivors in the search. These would result in reduced number of comparisons and consequently reduced energy use. Multipliers are complex units and play an important role in finding the overall area, speed and power consumption of digital designs. By using the multiplier we can minimize the parameters like latency, complexity and power consumption.
In OFDM-IDMA scheme, intersymbol interference (ISI) is resolved by the OFDM layer and multiple access interference (MAI) is suppressed by the IDMA layer at low cost . However OFDM-IDMA scheme suffers high peakto-average power ratio (PAPR) problem. For removing high PAPR problem a hybrid multiple access scheme SC-FDM-IDMA has been proposed. In this paper, bit error rate (BER) performance comparison of SC-FDM-IDMA scheme, OFDM-IDMA scheme and IDMA scheme have been duly presented. Moreover, the BER performance of various subcarrier mapping methods for SC-FDM-IDMA scheme as well as other results with variation of different parameters have also been demonstrated. Finally simulation result for BER performance improvement has been shown employing BCH code. All the simulation results demonstrate the suitability of SC-FDMIDMA scheme for wireless communication under AWGN channel environment.
Rate Distortion Performance for Joint Source Channel Coding of JPEG image Ove...CSCJournals
This paper presents the rate distortion behavior of Joint Source Channel Coding (JSCC) scheme for still image transmission. The focus is on DCT based Source coding JPEG, Rate Compatible Punctured Convolution codes (RCPC) for transmission over Additive White Gaussian Noise (AWGN) channel under the constraint of fixed transmission bandwidth. Information transmission has a tradeoff between compression ratio and received quality of image. The compressed stream is more susceptible to channel errors, thus error control coding techniques are used along with images to minimize the effect of channel errors. But there is a clear tradeoff between channel coding redundancies versus source quality with constant channel bit rate. This paper proposes JSCC scheme based on Unequal Error Protection (UEP) for robust image transmission. With the conventional error control coding schemes that uses Equal Error Protection (EEP), all the information bits are equally protected. The use of the UEP schemes provides a varying amount of error protection according to the importance of the data. The received image quality can be improved using UEP compared to Equal Error Protection (EEP).
Hardware implementation of (63, 51) bch encoder and decoder for wban using lf...ijitjournal
Error Correcting Codes are required to have a reliable communication through a medium that has an
unacceptable bit error rate and low signal to noise ratio. In IEEE 802.15.6 2.4GHz Wireless Body Area
Network (WBAN), data gets corrupted during the transmission and reception due to noises and
interferences. Ultra low power operation is crucial to prolong the life of implantable devices. Hence simple
block codes like BCH (63, 51, 2) can be employed in the transceiver design of 802.15.6 Narrowband PHY.
In this paper, implementation of BCH (63, 51, t = 2) Encoder and Decoder using VHDL is discussed. The
incoming 51 bits are encoded into 63 bit code word using (63, 51) BCH encoder. It can detect and correct
up to 2 random errors. The design of an encoder is implemented using Linear Feed Back Shift Register
(LFSR) for polynomial division and the decoder design is based on syndrome calculator, inversion-less
Berlekamp-Massey algorithm (BMA) and Chien search algorithm. Synthesis and simulation were carried
out using Xilinx ISE 14.2 and ModelSim 10.1c. The codes are implemented over Virtex 4 FPGA device and
tested on DN8000K10PCIE Logic Emulation Board. To the best of our knowledge, it is the first time an
implementation of (63, 51) BCH encoder and decoder carried out.
Reliability Level List Based Iterative SISO Decoding Algorithm for Block Turb...TELKOMNIKA JOURNAL
An iterative Reliability Level List (RLL) based soft-input soft-output (SISO) decoding algorithm has been proposed for Block Turbo Codes (BTCs). The algorithm ingeniously adapts the RLL based decoding algorithm for the constituent block codes, which is a soft-input hard-output algorithm. The extrinsic information is calculated using the reliability of these hard-output decisions and is passed as soft-input to the iterative turbo decoding process. RLL based decoding of constituent codes estimate the optimal transmitted codeword through a directed minimal search. The proposed RLL based decoder for the constituent code replaces the Chase-2 based constituent decoder in the conventional SISO scheme. Simulation results show that the proposed algorithm has a clear advantage of performance improvement over conventional Chase-2 based SISO decoding scheme with reduced decoding latency at lower noise levels.
FPGA Implementation of Viterbi Decoder using Hybrid Trace Back and Register E...ijsrd.com
Error correction is an integral part of any communication system and for this purpose, the convolution codes are widely used as forward error correction codes. For decoding of convolution codes, at the receiver end Viterbi Decoder is being employed. The parameters of Viterbi algorithm can be changed to suit a specific application. The high speed and small area are two important design parameters in today’s wireless technology. In this paper, a high speed feed forward viterbi decoder has been designed using hybrid track back and register exchange architecture and embedded BRAM of target FPGA. The proposed viterbi decoder has been designed with Matlab, simulated with Xilinx ISE 8.1i Tool, synthesized with Xilinx Synthesis Tool (XST), and implemented on Xilinx Virtex4 based xc4vlx15 FPGA device. The results show that the proposed design can operate at an estimated frequency of 107.7 MHz by consuming considerably less resources on target device to provide cost effective solution for wireless applications.
Design, Analysis and Implementation of Modified Luby Transform CodeIOSR Journals
Abstract : Bit losses in erasure channels like computer networks are of great concern. The existing methods to combat bit losses are either inefficient or time consuming due to the retransmission protocols involved. Through this paper, we propose a Modified Luby Transform (MLT) coding scheme to efficiently transmit data over live computer networks. The MLT code can combat bit losses as well as eliminate the need for retransmission. The usability and reliability of the proposed MLT code is verified by testing it on a live computer network. Keywords : Erasure channel, Fountain Codes, Luby Transform Codes , Wired Networks, Wireless Networks
International Journal of Engineering Research and DevelopmentIJERD Editor
Electrical, Electronics and Computer Engineering,
Information Engineering and Technology,
Mechanical, Industrial and Manufacturing Engineering,
Automation and Mechatronics Engineering,
Material and Chemical Engineering,
Civil and Architecture Engineering,
Biotechnology and Bio Engineering,
Environmental Engineering,
Petroleum and Mining Engineering,
Marine and Agriculture engineering,
Aerospace Engineering.
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.
Joint Fixed Power Allocation and Partial Relay Selection Schemes for Cooperat...TELKOMNIKA JOURNAL
In the future wireless systems, non-orthogonal multiple-access (NOMA) with partial relay selection scheme is considered as developing research topic. In this paper, dual-hop relaying systems is deployed for NOMA, in which the signals are communicated with the assistance of decode-and-forward (DF) scheme. This paper presents exact expressions for outage probability over independent Rayleigh fading channels, and two partial relay selection schemes are provided. Using analytical result and Monte-Carlo method, we introduce forwarding strategy selection for fixed user allocation and exactness of derived formula is checked. The presented simulations confirm the the advantage of such proposed NOMA, and the effectiveness of the proposed forwarding strategy.
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.
Reduced Energy Min-Max Decoding Algorithm for Ldpc Code with Adder Correction...ijceronline
In this paper, high linear architectures for analysing the first two maximum or minimum values are of paramount importance in several uses, including iterative decoders. We proposed the adder and LDPC. The min-sum processing step that it gives only two different output magnitude values irrespective of the number of incoming bit-to check messages. These new micro-architecture layouts would employ the minimum number of comparators by exploiting the concept of survivors in the search. These would result in reduced number of comparisons and consequently reduced energy use. Multipliers are complex units and play an important role in finding the overall area, speed and power consumption of digital designs. By using the multiplier we can minimize the parameters like latency, complexity and power consumption.
In OFDM-IDMA scheme, intersymbol interference (ISI) is resolved by the OFDM layer and multiple access interference (MAI) is suppressed by the IDMA layer at low cost . However OFDM-IDMA scheme suffers high peakto-average power ratio (PAPR) problem. For removing high PAPR problem a hybrid multiple access scheme SC-FDM-IDMA has been proposed. In this paper, bit error rate (BER) performance comparison of SC-FDM-IDMA scheme, OFDM-IDMA scheme and IDMA scheme have been duly presented. Moreover, the BER performance of various subcarrier mapping methods for SC-FDM-IDMA scheme as well as other results with variation of different parameters have also been demonstrated. Finally simulation result for BER performance improvement has been shown employing BCH code. All the simulation results demonstrate the suitability of SC-FDMIDMA scheme for wireless communication under AWGN channel environment.
Design and implementation of log domain decoder IJECEIAES
Low-Density-Parity-Check (LDPC) code has become famous in communications systems for error correction, as an advantage of the robust performance in correcting errors and the ability to meet all the requirements of the 5G system. However, the mot challenge faced researchers is the hardware implementation, because of higher complexity and long run-time. In this paper, an efficient and optimum design for log domain decoder has been implemented using Xilinx system generator with FPGA device Kintex7 (XC7K325T-2FFG900C). Results confirm that the proposed decoder gives a Bit Error Rate (BER) very closed to theory calculations which illustrate that this decoder is suitable for next generation demand which needs a high data rate with very low BER.
Performances Concatenated LDPC based STBC-OFDM System and MRC Receivers IJECEIAES
This paper presents the bit error rate performance of the low density parity check (LDPC) with the concatenation of convolutional channel coding based orthogonal frequency-division-multiplexing (OFDM) using space time block coded (STBC). The OFDM wireless communication system incorporates 3/4rated convolutional encoder under various digital modulations (BPSK, QPSK and QAM) over an additative white gaussian noise (AWGN) and fading (Raleigh and Rician) channels. At the receiving section of the simulated system, Maximum Ratio combining (MRC) channel equalization technique has been implemented to extract transmitted symbols without enhancing noise power.
Implementation of Joint Network Channel Decoding Algorithm for Multiple Acces...csandit
In this paper, we consider a Joint Network Channel Decoding (JNCD) algorithm applied to a
wireless network consisting to M users. For this purpose M sources desire to send information
to one receiver by the help of an intermediate node which is the relay. The Physical Layer
Network Coding (PLNC) allows the relay to decode the combined information being sent from
different transmitters. Then, it forwards additional information to the destination node which
receives also signals from source nodes. An iterative JNCD algorithm is developed at the
receiver to estimate the information being sent from each transmitter. Simulation results show
that the Bit Error Rate (BER) can be decreased by using this concept comparing to the
reference one which doesn’t consider the network coding.
IMPLEMENTATION OF JOINT NETWORK CHANNEL DECODING ALGORITHM FOR MULTIPLE ACCES...cscpconf
In this paper, we consider a Joint Network Channel Decoding (JNCD) algorithm applied to a wireless network consisting to M users. For this purpose M sources desire to send information
to one receiver by the help of an intermediate node which is the relay. The Physical Layer Network Coding (PLNC) allows the relay to decode the combined information being sent from different transmitters. Then, it forwards additional information to the destination node which receives also signals from source nodes. An iterative JNCD algorithm is developed at the receiver to estimate the information being sent from each transmitter. Simulation results show that the Bit Error Rate (BER) can be decreased by using this concept comparing to the reference one which doesn’t consider the network coding.
International Journal of Engineering Research and Applications (IJERA) aims to cover the latest outstanding developments in the field of all Engineering Technologies & science.
International Journal of Engineering Research and Applications (IJERA) is a team of researchers not publication services or private publications running the journals for monetary benefits, we are association of scientists and academia who focus only on supporting authors who want to publish their work. The articles published in our journal can be accessed online, all the articles will be archived for real time access.
Our journal system primarily aims to bring out the research talent and the works done by sciaentists, academia, engineers, practitioners, scholars, post graduate students of engineering and science. This journal aims to cover the scientific research in a broader sense and not publishing a niche area of research facilitating researchers from various verticals to publish their papers. It is also aimed to provide a platform for the researchers to publish in a shorter of time, enabling them to continue further All articles published are freely available to scientific researchers in the Government agencies,educators and the general public. We are taking serious efforts to promote our journal across the globe in various ways, we are sure that our journal will act as a scientific platform for all researchers to publish their works online.
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
NON-STATISTICAL EUCLIDEAN-DISTANCE SISO DECODING OF ERROR-CORRECTING CODES OV...IJCSEA Journal
In this paper we describe novel non-statistical Euclidean distance soft-input, soft-output (SISO) decoding algorithms for the three currently most important error-correcting codes: the low-density parity-check (LDPC), turbo and polar codes. The metric is squared Euclidean distance, and the decoders operate using an antilog-log (AL) process. We have investigated the simulated bit-error rate (BER) performance of these non-statistical algorithms on three channel models: the additive White Gaussian noise (AWGN), the Rayleigh fading and Middleton’s Class-A impulsive noise channels, and compare them with the BER performances of the corresponding statistical decoding algorithms for the three codes and channels. In all cases the performance over the AWGN channel of the non-statistical algorithms is almost the same or slightly better than that of the statistical algorithms. In some cases the performance over the two nonGaussian channels of the non-statistical algorithms is worse than that of the statistical algorithms, but the use of a simple signal amplitude limiter placed before the decoder input significantly improves the actual and relative performances of the algorithms. Thus there is no performance loss, and sometimes a significant performance gain, for the proposed decoding algorithms. A major advantage of our algorithms is that estimation of the channel signal-to-noise ratio is not required, which in practice simplifies system implementation. In addition, we have found that the processing complexity of the non-statistical algorithms is similar or slightly less than that of the corresponding statistical algorithms, and is significantly less for the LDPC codes over all of the channels.
NON-STATISTICAL EUCLIDEAN-DISTANCE SISO DECODING OF ERROR-CORRECTING CODES OV...IJCSEA Journal
In this paper we describe novel non-statistical Euclidean distance soft-input, soft-output (SISO) decoding
algorithms for the three currently most important error-correcting codes: the low-density parity-check
(LDPC), turbo and polar codes. The metric is squared Euclidean distance, and the decoders operate using
an antilog-log (AL) process. We have investigated the simulated bit-error rate (BER) performance of these
non-statistical algorithms on three channel models: the additive White Gaussian noise (AWGN), the
Rayleigh fading and Middleton’s Class-A impulsive noise channels, and compare them with the BER
performances of the corresponding statistical decoding algorithms for the three codes and channels. In all
cases the performance over the AWGN channel of the non-statistical algorithms is almost the same or
slightly better than that of the statistical algorithms. In some cases the performance over the two nonGaussian channels of the non-statistical algorithms is worse than that of the statistical algorithms, but the
use of a simple signal amplitude limiter placed before the decoder input significantly improves the actual
and relative performances of the algorithms. Thus there is no performance loss, and sometimes a
significant performance gain, for the proposed decoding algorithms. A major advantage of our algorithms
is that estimation of the channel signal-to-noise ratio is not required, which in practice simplifies system
implementation. In addition, we have found that the processing complexity of the non-statistical algorithms
is similar or slightly less than that of the corresponding statistical algorithms, and is significantly less for
the LDPC codes over all of the channels.
NON-STATISTICAL EUCLIDEAN-DISTANCE SISO DECODING OF ERROR-CORRECTING CODES OV...IJCSEA Journal
In this paper we describe novel non-statistical Euclidean distance soft-input, soft-output (SISO) decoding
algorithms for the three currently most important error-correcting codes: the low-density parity-check
(LDPC), turbo and polar codes. The metric is squared Euclidean distance, and the decoders operate using
an antilog-log (AL) process. We have investigated the simulated bit-error rate (BER) performance of these
non-statistical algorithms on three channel models: the additive White Gaussian noise (AWGN), the
Rayleigh fading and Middleton’s Class-A impulsive noise channels, and compare them with the BER
performances of the corresponding statistical decoding algorithms for the three codes and channels. In all
cases the performance over the AWGN channel of the non-statistical algorithms is almost the same or
slightly better than that of the statistical algorithms. In some cases the performance over the two nonGaussian channels of the non-statistical algorithms is worse than that of the statistical algorithms, but the
use of a simple signal amplitude limiter placed before the decoder input significantly improves the actual
and relative performances of the algorithms. Thus there is no performance loss, and sometimes a
significant performance gain, for the proposed decoding algorithms. A major advantage of our algorithms
is that estimation of the channel signal-to-noise ratio is not required, which in practice simplifies system
implementation. In addition, we have found that the processing complexity of the non-statistical algorithms
is similar or slightly less than that of the corresponding statistical algorithms, and is significantly less for
the LDPC codes over all of the channels
NON-STATISTICAL EUCLIDEAN-DISTANCE SISO DECODING OF ERROR-CORRECTING CODES OV...IJCSEA Journal
n this paper we describe novel non-statistical Euclidean distance soft-input, soft-output (SISO) decoding
algorithms for the three currently most important error-correcting codes: the low-density parity-check
(LDPC), turbo and polar codes. The metric is squared Euclidean distance, and the decoders operate using
an antilog-log (AL) process. We have investigated the simulated bit-error rate (BER) performance of these
non-statistical algorithms on three channel models: the additive White Gaussian noise (AWGN), the
Rayleigh fading and Middleton’s Class-A impulsive noise channels, and compare them with the BER
performances of the corresponding statistical decoding algorithms for the three codes and channels. In all
cases the performance over the AWGN channel of the non-statistical algorithms is almost the same or
slightly better than that of the statistical algorithms.
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Diversity combining is a technique in wireless network that uses multiple antenna system to improve the quality of radio signal. Mobile radio system suffers multipath propagation due to signal obstruction in the channel. A new hybridized diversity combining scheme consisting of Equal Gain Combining (EGC) and Maximal Ratio Combining (MRC) was proposed in this paper. Theperformance of the hybrid model was evaluated using Outage Probability (Pout) and Processing time (Pt) at different Signal-to-Noise Ratio (SNR) and Signal Paths (L=2,3) for 4-QAM and 8-QAM Modulation Schemes. A mathematical expression for the hybrid EGC-MRC was realized using the Probability Density Function (PDF) of the Nakagami fading channel. MATLAB R2015b software was used for the model simulation. The result shows that hybrid EGC-MRC outperforms the standalone EGC and MRC schemes by having lower Pout and Pt values. Hence, hybrid EGC-MRC exhibits enhanced potentials to mitigate multipath propagation at reduced
system complexity.
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Nowdays, different applications require a modern generation of mobile communication systems;
long term evolution (LTE) is a candidate to achieve this purpose. One important challenge in wireless
communications, including LTE systems, is the suitable techniques of controlling errors that degrade
system performance in transmission systems over multipath fading channels. Different forward Error
correction (FEC) techniqes are required to improve the robustness of transmission channels. In this paper,
Reed-Solomon (RS) codes were used with a downlink LTE system over a LTE-MIMO channel. This
research contributes by combining RS codes that have low decoding complexity (by using hard decision
decoding) with a LTE-MIMO channel to improve downlink LTE system performance. The results show that
using RS codes clearly improves LTE system performance and thus decreases Bit Error Rates (BER)
more than convolutional and turbo codes which have high decoding complexity. Lastly, the results show
also extra improvements of downlink LTE system performance by increasing the number of antennas of
the LTE-MIMO channel.
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We present transmission of five users with 5 WDM × 4 TDM × 5 CODE channel on 3D
OCDMA system based on Model B using GF (5) with varying receiver attenuation at 1Gbps, 2 Gbps, 5Gbps and 10Gbps data rates on OPTSIM.
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Soft Decision Scheme for Multiple Descriptions Coding over Rician Fading Channels
1. A. H. M. Almawgani & M. F. M. Salleh
International Journal of Image Processing (IJIP), Volume (3) : Issue (1) 12
Soft Decision Scheme for Multiple Descriptions Coding over
Rician Fading Channels
A. H. M. Almawgani and M. F. M. Salleh almawgani2003@hotmail.com
School of Electrical and Electronic,
Universiti Sains Malaysia, 14300 Nibong
Tebal,PulauPinang,Malaysia fadzlisalleh@eng.usm.my
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ABSTRACT
This paper presents a new MDC scheme for robust wireless data
communications. The soft detection making of the MDC scheme utilises the
statistical received data error obtained from channel decoding. The coded bit
stream in the system is protected using either the Reed Solomon (RS) or Low
Density Parity Check Codes (LDPC) channel coding scheme. Simulation
results show that this system has some significant performance improvements
over the single description or single channel transmission systems in terms of
symbol error rate and peak signal-to-noise ratio PSNR. The system with RS
codes is 2 to 5 dB better than single description. The system with LDPC
channel codes is 6 to10 dB better than the single description.
Keywords: Multiple Descriptions Coding, Rician fading channel and Image transmission.
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1. INTRODUCTION
In recent years, many researchers have involved in the development of Multiple Descriptions
Coding (MDC) techniques which improves the robustness of wireless data transmission as
presented in [1-9]. In MDC technique, retransmission of the lost information is not required
since the receive data are sufficient for quality reconstruction. Retransmission often incurs
unacceptable delay. This makes MDC particularly appealing for real-time interactive multimedia
applications such as multimedia communication for mobile and video conferencing.
There have been lot of research activities done for applications in multimedia communication.
For example, in [1-2] present the works done for image coding, in [3-4] present the works done
for video coding, and in [5-7] present the works done for audio as well as speech coding. Other
related works to MDC technique include the use of quantization such as MD scalar quantizers
(MDSQ) as presented in [8] and the work that involves transformation technique, such as MD
Transform Coding (MDTC) as presented in [9].
In this paper, a new MDC coding scheme is introduced where the soft decision making of the
reconstructed image is based on the statistical data error channel decoding. An image
transmission system that consists of the new MDC scheme and channel coding scheme is
simulated over wireless channels. The coded bit stream is protected either using the RS or
LDPC as well as the hybrid of RS and LDPC codes. Results for the system with RS codes are
2 to 5 dB better than single description. Results for the system with LDPC codes are 6 to 10 dB
better than the single description.
a. Proposed MDC scheme
The proposed image transmission system that consists of the new MDC scheme and channel
coding is illustrated in Fig. 1.
2. A. H. M. Almawgani & M. F. M. Salleh
International Journal of Image Processing (IJIP), Volume (3) : Issue (1) 13
2D
1D
FIGURE 1: A Multiple Description System
An image is first divided into several packets, where the size of each packet is determined by
size of the image row. At this stage the data are considered single description (SD) data. Then,
each element ),( jiX in SD packet is converted to a pair of elements ( ),(1 jiD , ),(2 jiD ). At this
stage the data are considered as multiple descriptions (MD) data. The conversion formula used
is as the following;
1
2
),(
),(1 +=
jiX
jiD 1
2
1),(
),(2
+
=
jiX
jiD
2
This can be considered as combining the neighbouring data (pixels) of the original data as shown in
Table 1.
Table 1: Single to Multiple Descriptions
),( jiX 1 2 3 4 5 6 7 8 9 10 …
),(1 jiD 1 2 3 4 5 6 …
),(2 jiD 1 2 3 4 5 …
The MD data sequences are then coded using either the RS codes or using the LDPC codes.
Both schemes use the same code rate of 1/3. Then, the encoded data are transmitted over
wireless channels after BPSK modulation process.
At the receiver, the data are first demodulated by the BPSK demodulator. Then, the data are
decoded using either the RS or LDPC decoder. The channel decoder has three outputs i.e. the
decoded MD data, sum of error in the packet (channel 1 error ( )iE1 or channel 2 error ( )iE2 ),
and symbol pairs
),( jiRk . Then the MD data are converted to a SD data. The next process is
the conversion of MD to SD data. This is the inverse of SD to MD process given by equation 3
and 4.
)1),((*2),( 11 −= jiRjiD 3
1),(*2),( 12 −= jiRjiD 4
0)(:),(:),( 110 == iEifiDiD 5
0)(:),(:),( 220 == iEifiDiD 6
The final process is the soft decision algorithm, where it takes the best data out of the two
channels. There are three possible inputs to this process;
The best packet will be received from channel 1, if no error occurs during transmission of the
whole packet as stated by equation 5.
The best packet will be received from channel 2, if no error occurs during transmission of the
whole packet as stated by equation 6.
If there are errors in each channel, the following steps are taken;
3. A. H. M. Almawgani & M. F. M. Salleh
International Journal of Image Processing (IJIP), Volume (3) : Issue (1) 14
a. If ( )iE1 > ( )iE2 : Choose packet from channel 2.
b. If ( )iE1 < ( )iE2 : Choose packet from channel 1.
c. If ( )iE1 = ( )iE2 : Compare each component from both packets, and the check the pixel
error PE1 and PE2 values. Choose the component where the PEi of zero value.
The entire process is summarised by the flow chart shown in Fig. 2.
Simulation Results
This section presents the simulation results of the system using two different channel coding
schemes. The first scheme uses RS channel coding and the transmission is carried out over
AWGN channel. The channel condition is varied by changing the signal to noise ration (SNR)
for each transmission. Then, a different channel i.e. the Rician fading channel is used. The
second scheme uses LDPC codes as channel coding. The standard image “Lena” is used as
the test image. The performance is measured based on the Peak Signal to Noise Ration
(PSNR) that serves as the quantitative measure of the quality for the reconstructed images.
FIGURE 2: Performance in AWGN channel
Table 2 shows the results obtained for image transmission system over AWGN channel. The
system consists of the new MDC algorithm and two channel coding schemes. The PSNR
performance of the reconstructed image is obtained for channel SNR from 1 dB to 10dB. This
results show that the system with LDPC performs better than RS codes at SNR lower than 10
dB.
SNR(dB)
PSNR(dB) 1 4 7 10
Channel 1 10.37 16.31 34.08 ∞
Channel 2 10.56 16.87 31.59 ∞Use RS channel codes
Combine between 1&2 10.56 18.81 41.56 ∞
Channel 1 ∞ ∞ ∞ ∞
Channel 2 ∞ ∞ ∞ ∞Use LDPC channel codes
Combine between 1&2 ∞ ∞ ∞ ∞
4. A. H. M. Almawgani & M. F. M. Salleh
International Journal of Image Processing (IJIP), Volume (3) : Issue (1) 15
1),(*2),(
)1),((*2),(
12
11
−=
−=
jiRjiD
jiRjiD
),(),( 20 jiDjiD =
),(),( 10 jiDjiD =
),(0 NMD
FIGURE 3: flow chart of MD to SD
Fig. 3 shows the results obtained for image transmission system over Rician fading channel. In
this simulation, a mobile system with the source rate of 100 kbps and carrier frequency of 900
MHz are assumed. The mobile speed of 120 km/h is used that gives the Maximum Doppler
shift as 100 Hz. The AWGN environment is assumed to be with every path in the Rician fading
channel. In the simulation, the frequency-selective “multiple paths” Rician channel uses the K-
factor equal 10 (K-factor defined as the ratio of signal power for line of sight (LOS) over the
scattered, reflected power).
This results show the performance of image transmission system with LDPC codes is better
than RS codes. The performance of MD system always outperforms the SD system. For
example, looking at 8 dB channel SNR in Fig. 3, for the systems with RS codes, there is almost
2 dB gain obtained by comparing the dotted lines. Similarly, for the systems with LDPC codes,
there is almost 5 dB gain obtained by comparing the continuous lines.. The better performance
of the system that uses LDPC codes is due to its excellent error correction capability as
compared to RS codes over the Rician fading channel.
5. A. H. M. Almawgani & M. F. M. Salleh
International Journal of Image Processing (IJIP), Volume (3) : Issue (1) 16
FIGURE 4: PSNR (dB) via frequency-selective “multiple path” Rician channel
1. Conclusions
In this paper the proposed MDC scheme for image transmission system together with two FEC
schemes are analysed. The technique has significantly improves the performance of image
transmission system in wireless channels. The proposed MDC scheme is an alternative
technique for image transmission in wireless channel where methods that use error control
schemes such as ARQ are not suitable due to the introduction of delay.
The MDC scheme increases robustness of data transmission. If a receiver gets only one
description (other descriptions is lost), it can still reconstruct image with lower but acceptable
quality. Simulation results have shown that the image transmission system with LDPC codes
performs better than RS codes for both simulation via AWGN and Rician fading channels.
Acknowledgements
This work is funded in part by MOSTI Science Fund with Grant Number 6013353, USM
Fellowship, and USM RU grant with Grant Number 814012.
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0 5 10 15 20 25
5
10
15
20
25
30
35
40
45
50
55
SNR (dB)
PSNR(dB)
Frequency-selective ("multiple path") Rician fading channel
Channel 1 using LDPC
Channel 2 using LDPC
combine between channel 1 & 2 using LDPC
Channel 1 using RS
Channel 2 using RS
combine between channel 1 & 2 using RS
![A. H. M. Almawgani & M. F. M. Salleh
International Journal of Image Processing (IJIP), Volume (3) : Issue (1) 12
Soft Decision Scheme for Multiple Descriptions Coding over
Rician Fading Channels
A. H. M. Almawgani and M. F. M. Salleh almawgani2003@hotmail.com
School of Electrical and Electronic,
Universiti Sains Malaysia, 14300 Nibong
Tebal,PulauPinang,Malaysia fadzlisalleh@eng.usm.my
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ABSTRACT
This paper presents a new MDC scheme for robust wireless data
communications. The soft detection making of the MDC scheme utilises the
statistical received data error obtained from channel decoding. The coded bit
stream in the system is protected using either the Reed Solomon (RS) or Low
Density Parity Check Codes (LDPC) channel coding scheme. Simulation
results show that this system has some significant performance improvements
over the single description or single channel transmission systems in terms of
symbol error rate and peak signal-to-noise ratio PSNR. The system with RS
codes is 2 to 5 dB better than single description. The system with LDPC
channel codes is 6 to10 dB better than the single description.
Keywords: Multiple Descriptions Coding, Rician fading channel and Image transmission.
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1. INTRODUCTION
In recent years, many researchers have involved in the development of Multiple Descriptions
Coding (MDC) techniques which improves the robustness of wireless data transmission as
presented in [1-9]. In MDC technique, retransmission of the lost information is not required
since the receive data are sufficient for quality reconstruction. Retransmission often incurs
unacceptable delay. This makes MDC particularly appealing for real-time interactive multimedia
applications such as multimedia communication for mobile and video conferencing.
There have been lot of research activities done for applications in multimedia communication.
For example, in [1-2] present the works done for image coding, in [3-4] present the works done
for video coding, and in [5-7] present the works done for audio as well as speech coding. Other
related works to MDC technique include the use of quantization such as MD scalar quantizers
(MDSQ) as presented in [8] and the work that involves transformation technique, such as MD
Transform Coding (MDTC) as presented in [9].
In this paper, a new MDC coding scheme is introduced where the soft decision making of the
reconstructed image is based on the statistical data error channel decoding. An image
transmission system that consists of the new MDC scheme and channel coding scheme is
simulated over wireless channels. The coded bit stream is protected either using the RS or
LDPC as well as the hybrid of RS and LDPC codes. Results for the system with RS codes are
2 to 5 dB better than single description. Results for the system with LDPC codes are 6 to 10 dB
better than the single description.
a. Proposed MDC scheme
The proposed image transmission system that consists of the new MDC scheme and channel
coding is illustrated in Fig. 1.](https://image.slidesharecdn.com/ijip16-160216093830/85/Soft-Decision-Scheme-for-Multiple-Descriptions-Coding-over-Rician-Fading-Channels-1-320.jpg)
