Forward-backward algorithm, used by watermark decoder for correcting non-binary synchronization errors, requires to traverse a very large scale trellis in order to achieve the proper posterior probability, leading to ...Forward-backward algorithm, used by watermark decoder for correcting non-binary synchronization errors, requires to traverse a very large scale trellis in order to achieve the proper posterior probability, leading to high computational complexity. In order to reduce the number of the states involved in the computation, an adaptive pruning method for the trellis is proposed. In this scheme, we prune the states which have the low forward-backward quantities below a carefully-chosen threshold. Thus, a wandering trellis with much less states is achieved, which contains most of the states with quite high probability. Simulation results reveal that, with the proper scaling factor, significant complexity reduction in the forward-backward algorithm is achieved at the expense of slight performance degradation.展开更多
Binary Polar Codes (BPCs) have advantages of high-efficiency and capacity-achieving but suffer from large latency due to the Successive-Cancellation List (SCL) decoding. Non-Binary Polar Codes (NBPCs) have been invest...Binary Polar Codes (BPCs) have advantages of high-efficiency and capacity-achieving but suffer from large latency due to the Successive-Cancellation List (SCL) decoding. Non-Binary Polar Codes (NBPCs) have been investigated to obtain the performance gains and reduce latency under the implementation of parallel architectures for multi-bit decoding. However, most of the existing works only focus on the Reed-Solomon matrix-based NBPCs and the probability domain-based non-binary polar decoding, which lack flexible structure and have a large computation amount in the decoding process, while little attention has been paid to general non-binary kernel-based NBPCs and Log-Likelihood Ratio (LLR) based decoding methods. In this paper, we consider a scheme of NBPCs with a general structure over GF(2m). Specifically, we pursue a detailed Monte-Carlo simulation implementation to determine the construction for proposed NBPCs. For non-binary polar decoding, an SCL decoding based on LLRs is proposed for NBPCs, which can be implemented with non-binary kernels of arbitrary size. Moreover, we propose a Perfect Polarization-Based SCL (PPB-SCL) algorithm based on LLRs to reduce decoding complexity by deriving a new update function of path metric for NBPCs and eliminating the path splitting process at perfect polarized (i.e., highly reliable) positions. Simulation results show that the bit error rate of the proposed NBPCs significantly outperforms that of BPCs. In addition, the proposed PPB-SCL decoding obtains about a 40% complexity reduction of SCL decoding for NBPCs.展开更多
A new non-binary decoding method, which is called Yaletharatalhussein decoding algorithm, is designed and implemented for decoding non-binary convolutional codes which is based on the trellis diagram representing the ...A new non-binary decoding method, which is called Yaletharatalhussein decoding algorithm, is designed and implemented for decoding non-binary convolutional codes which is based on the trellis diagram representing the convolutional encoder. Yaletharatalhussein decoding algorithm outperforms the Viterbi algorithm and other algorithms in its simplicity, very small computational complexity, decoding reliability for high states TCM codes that suitable for Fourth-Generation (4G), decreasing errors with increasing word length, and easy to implement with real-time applications. The proposed Yaletharatalhussein decoding algorithm deals with non-binary error control coding of the convolutional and TCM codes. Convolutional codes differ from block codes in that a block code takes a fixed message length and encodes it, whereas a convolutional code can encode a continuous stream of data, and a hard-decision decoding can easily be realized using the Yaletharatalhussein algorithm. The idea of non-binary codes has been extended for symbols defined over rings of integers, which outperform binary codes with only a small increase in decoding complexity. The simulation results show that the performance of the nonbinary TCM-based Yaletharatalhussein algorithm outperforms the binary and non-binary decoding methods.展开更多
This paper deals with the MIMO-OFDM technique that is applied to the fourth generation (4G) of the wireless communication systems, this technique can provide high data rate transmission without increasing transmit pow...This paper deals with the MIMO-OFDM technique that is applied to the fourth generation (4G) of the wireless communication systems, this technique can provide high data rate transmission without increasing transmit power and expanding bandwidth, it can also efficiently use space resources and has a bright future. It presents the channel coding assisted STBC-OFDM systems, and employs the Coded Modulation techniques (CM), since the signal bandwidth available for wireless communications is limited. The proposed system deals with Non-binary error control coding of the TCM-aided STBC-OFDM scheme for transmissions over the Rayleigh channel. A new non-binary decoding method, Yaletharatalhussein decoding algorithm, is designed and implemented for decoding non-binary convolutional codes, which is based on the trellis diagram representing the convolutional encoder. Yaletharatalhussein decoding algorithm outperforms the Viterbi algorithm and other algorithms in its simplicity, very small computational complexity, decoding reliability for high states TCM codes that are suitable for Fourth-Generation (4G), decreasing errors with increasing word length, and easy to implement with real-time applications. The simulation results show that the performance of the non-binary TCM-based Yaletharatalhussein decoding algorithm-assisted STBC-OFDM scheme outperforms the binary and non-binary decoding methods.展开更多
Non-binary low density parity check （NB-LDPC） codes are considered as preferred candidate in conditions where short/medium codeword length codes and better performance at low signal to noise ratios （SNR） are requi...Non-binary low density parity check （NB-LDPC） codes are considered as preferred candidate in conditions where short/medium codeword length codes and better performance at low signal to noise ratios （SNR） are required. They have better burst error correcting performance, especially with high order Galois fields （GF）. A shared comparator （SCOMP） architecture for elementary of check node （ECN）/elementary of variable node （EVN） to reduce decoder complexity is introduced because high complexity of check node （CN） and variable node （VN） prevent NB-LDPC decoder from widely applications. The decoder over GF（16） is based on the extended rain-sum （EMS） algorithm. The decoder matrix is an irregular structure as it can provide better performance than regular ones. In order to provide higher throughput and increase the parallel processing efficiency, the clock which is 8 times of the system frequency is adopted in this paper to drive the CN/VN modules. The decoder complexity can be reduced by 28% from traditional decoder when SCOMP architecture is introduced. The result of synthesis software shows that the throughput can achieve 34 Mbit/s at 10 iterations. The proposed architecture can be conveniently extended to GF such as GF（64） or GF（256）. Compared with previous works, the decoder proposed in this paper has better hardware efficiency for practical applications.展开更多
In this paper, we present a graphics processing unit(GPU)-based implementation of a weighted bit-reliability based(w BRB) decoder for non-binary LDPC(NB-LDPC) codes. To achieve coalesced memory accesses, an efficient ...In this paper, we present a graphics processing unit(GPU)-based implementation of a weighted bit-reliability based(w BRB) decoder for non-binary LDPC(NB-LDPC) codes. To achieve coalesced memory accesses, an efficient data structure for the w BRB algorithm is proposed. Based on the Single-Instruction Multiple-Threads(SIMT) programming model, a novel mapping strategy with high intra-frame parallelism is presented to improve the latency and throughput performance. Moreover, by using Single-Instruction Multiple-Data(SIMD) intrinsics, four 8-bit message elements are packed into a 32-bit unit and simultaneously processed. Experimental results show that the proposed w BRB decoder provides good tradeoff between error performance and throughput for the codes with relatively large column degrees or high rates.展开更多
The non-binary(NB) Irregular Repeat Accumulate(IRA) codes, as a subclass of NB LDPC codes, potentially have an excellent error-correcting performance. They are also known to provide linear complexity of encoding, but ...The non-binary(NB) Irregular Repeat Accumulate(IRA) codes, as a subclass of NB LDPC codes, potentially have an excellent error-correcting performance. They are also known to provide linear complexity of encoding, but the basic encoding method with the serial rate-1 accumulator significantly limits the encoder throughput. Then the objective of the research presented in this paper is to develop an encoding method pro- viding significantly increased throughput of an NB-IRA encoder altogether with a flexible code construction methods for the structured(S-NB-IRA) codes eligible for the proposed encoding method. For this purpose, we reformulate the classic encoding algorithm to fit into the partial parallel encoder architecture. We propose the S-NB-IRA encoder block diagram and show that its estimated throughput is proportional to the submatrix size of the parity check matrix, which guarantees a wide complexity- throughput tradeoff. Then, in order to facilitate the S-NB-IRA coding systems design, we present a computer search algorithm for the construction of good S-NB-IRA codes. The algorithm aims at optimizing the code graph topology along with selecting an appropriate non-binary elements in the parity check matrix. Numerical results show that the constructed S-NB-IRA codes significantly outperform the binary IRA and S-IRA codes, while their performance is similar to the best unstructured NB-LDPC codes.展开更多
为解决导航电文信息速率制约导航系统性能的问题,提出了一种基于码移键控调制和多进制低密度奇偶校验码的新型全球卫星导航系统（GNSS）信号编码调制技术.在-130 d Bm的接收电平、误码率不大于10-7的指标下,该技术可以达到1 500 bit/s...为解决导航电文信息速率制约导航系统性能的问题,提出了一种基于码移键控调制和多进制低密度奇偶校验码的新型全球卫星导航系统（GNSS）信号编码调制技术.在-130 d Bm的接收电平、误码率不大于10-7的指标下,该技术可以达到1 500 bit/s的有效信息速率,并且具有信号结构简单、与现有GNSS信号兼容性强等优势.理论分析和仿真结果证明,该技术突破了现有卫星导航信号体制下的信息速率极限,能够克服复杂信号结构造成的难以独立捕获跟踪的问题,在卫星导航系统中有比较重要的实用价值.展开更多
利用变量节点符号可靠度在迭代过程中的分布特征,提出了一种基于可靠度差值特征的自适应判决多元低密度奇偶校验(Low Density Parity Check, LDPC)译码算法。整个迭代过程划分为两个阶段,针对不同阶段节点可靠度的差值特征分别采用不同...利用变量节点符号可靠度在迭代过程中的分布特征,提出了一种基于可靠度差值特征的自适应判决多元低密度奇偶校验(Low Density Parity Check, LDPC)译码算法。整个迭代过程划分为两个阶段,针对不同阶段节点可靠度的差值特征分别采用不同的判决策略:前期阶段,采用传统的基于最大可靠度的判决策略;后期阶段,根据最大、次大可靠度之间的差值特征,设计自适应的码元符号判决策略。仿真结果表明,所提算法在相当的译码复杂度前提下,能获得0.15~0.4 dB的性能增益。同时,对于列重较小的LDPC码,具有更低的译码错误平层。展开更多
空间光通信技术是传输高速语音图像等数据信息的重要手段,为了解决星地激光通信系统中大气湍流效应的影响问题,提出一种低译码复杂度的多进制低密度奇偶校验(LDPC)码结合脉冲位置调制(PPM)的传输方案。所构造的多进制LDPC码不仅具有准...空间光通信技术是传输高速语音图像等数据信息的重要手段,为了解决星地激光通信系统中大气湍流效应的影响问题,提出一种低译码复杂度的多进制低密度奇偶校验(LDPC)码结合脉冲位置调制(PPM)的传输方案。所构造的多进制LDPC码不仅具有准循环特性,在硬件上易于用移位寄存器实现,且可以根据PPM的调制阶数灵活构造多进制LDPC码,优化系统级联结构。仿真结果表明,在弱湍流信道下此类码具较好的误码性能和较低的错误平层。在SER=10-6时,相比于基于GF(29)的RS(511,305)码,码率为0.88的多进制LDPC码约有4.75 d B的净编码增益。展开更多
基金supported in part by National Natural Science Foundation of China (61101114, 61671324) the Program for New Century Excellent Talents in University (NCET-12-0401)
文摘Forward-backward algorithm, used by watermark decoder for correcting non-binary synchronization errors, requires to traverse a very large scale trellis in order to achieve the proper posterior probability, leading to high computational complexity. In order to reduce the number of the states involved in the computation, an adaptive pruning method for the trellis is proposed. In this scheme, we prune the states which have the low forward-backward quantities below a carefully-chosen threshold. Thus, a wandering trellis with much less states is achieved, which contains most of the states with quite high probability. Simulation results reveal that, with the proper scaling factor, significant complexity reduction in the forward-backward algorithm is achieved at the expense of slight performance degradation.
基金supported in part by the National Natural Science Foundation of China under Grant 61401407in part by the Fundamental Research Funds for the Central Universities under Grant CUC2019B067.
文摘Binary Polar Codes (BPCs) have advantages of high-efficiency and capacity-achieving but suffer from large latency due to the Successive-Cancellation List (SCL) decoding. Non-Binary Polar Codes (NBPCs) have been investigated to obtain the performance gains and reduce latency under the implementation of parallel architectures for multi-bit decoding. However, most of the existing works only focus on the Reed-Solomon matrix-based NBPCs and the probability domain-based non-binary polar decoding, which lack flexible structure and have a large computation amount in the decoding process, while little attention has been paid to general non-binary kernel-based NBPCs and Log-Likelihood Ratio (LLR) based decoding methods. In this paper, we consider a scheme of NBPCs with a general structure over GF(2m). Specifically, we pursue a detailed Monte-Carlo simulation implementation to determine the construction for proposed NBPCs. For non-binary polar decoding, an SCL decoding based on LLRs is proposed for NBPCs, which can be implemented with non-binary kernels of arbitrary size. Moreover, we propose a Perfect Polarization-Based SCL (PPB-SCL) algorithm based on LLRs to reduce decoding complexity by deriving a new update function of path metric for NBPCs and eliminating the path splitting process at perfect polarized (i.e., highly reliable) positions. Simulation results show that the bit error rate of the proposed NBPCs significantly outperforms that of BPCs. In addition, the proposed PPB-SCL decoding obtains about a 40% complexity reduction of SCL decoding for NBPCs.
文摘A new non-binary decoding method, which is called Yaletharatalhussein decoding algorithm, is designed and implemented for decoding non-binary convolutional codes which is based on the trellis diagram representing the convolutional encoder. Yaletharatalhussein decoding algorithm outperforms the Viterbi algorithm and other algorithms in its simplicity, very small computational complexity, decoding reliability for high states TCM codes that suitable for Fourth-Generation (4G), decreasing errors with increasing word length, and easy to implement with real-time applications. The proposed Yaletharatalhussein decoding algorithm deals with non-binary error control coding of the convolutional and TCM codes. Convolutional codes differ from block codes in that a block code takes a fixed message length and encodes it, whereas a convolutional code can encode a continuous stream of data, and a hard-decision decoding can easily be realized using the Yaletharatalhussein algorithm. The idea of non-binary codes has been extended for symbols defined over rings of integers, which outperform binary codes with only a small increase in decoding complexity. The simulation results show that the performance of the nonbinary TCM-based Yaletharatalhussein algorithm outperforms the binary and non-binary decoding methods.
文摘This paper deals with the MIMO-OFDM technique that is applied to the fourth generation (4G) of the wireless communication systems, this technique can provide high data rate transmission without increasing transmit power and expanding bandwidth, it can also efficiently use space resources and has a bright future. It presents the channel coding assisted STBC-OFDM systems, and employs the Coded Modulation techniques (CM), since the signal bandwidth available for wireless communications is limited. The proposed system deals with Non-binary error control coding of the TCM-aided STBC-OFDM scheme for transmissions over the Rayleigh channel. A new non-binary decoding method, Yaletharatalhussein decoding algorithm, is designed and implemented for decoding non-binary convolutional codes, which is based on the trellis diagram representing the convolutional encoder. Yaletharatalhussein decoding algorithm outperforms the Viterbi algorithm and other algorithms in its simplicity, very small computational complexity, decoding reliability for high states TCM codes that are suitable for Fourth-Generation (4G), decreasing errors with increasing word length, and easy to implement with real-time applications. The simulation results show that the performance of the non-binary TCM-based Yaletharatalhussein decoding algorithm-assisted STBC-OFDM scheme outperforms the binary and non-binary decoding methods.
基金supported by the Foundation of the Chinese Academy of Sciences (KGFZD-135-16-015)
文摘Non-binary low density parity check （NB-LDPC） codes are considered as preferred candidate in conditions where short/medium codeword length codes and better performance at low signal to noise ratios （SNR） are required. They have better burst error correcting performance, especially with high order Galois fields （GF）. A shared comparator （SCOMP） architecture for elementary of check node （ECN）/elementary of variable node （EVN） to reduce decoder complexity is introduced because high complexity of check node （CN） and variable node （VN） prevent NB-LDPC decoder from widely applications. The decoder over GF（16） is based on the extended rain-sum （EMS） algorithm. The decoder matrix is an irregular structure as it can provide better performance than regular ones. In order to provide higher throughput and increase the parallel processing efficiency, the clock which is 8 times of the system frequency is adopted in this paper to drive the CN/VN modules. The decoder complexity can be reduced by 28% from traditional decoder when SCOMP architecture is introduced. The result of synthesis software shows that the throughput can achieve 34 Mbit/s at 10 iterations. The proposed architecture can be conveniently extended to GF such as GF（64） or GF（256）. Compared with previous works, the decoder proposed in this paper has better hardware efficiency for practical applications.
基金the National Natural Science Foundation of China (91438116)
文摘In this paper, we present a graphics processing unit(GPU)-based implementation of a weighted bit-reliability based(w BRB) decoder for non-binary LDPC(NB-LDPC) codes. To achieve coalesced memory accesses, an efficient data structure for the w BRB algorithm is proposed. Based on the Single-Instruction Multiple-Threads(SIMT) programming model, a novel mapping strategy with high intra-frame parallelism is presented to improve the latency and throughput performance. Moreover, by using Single-Instruction Multiple-Data(SIMD) intrinsics, four 8-bit message elements are packed into a 32-bit unit and simultaneously processed. Experimental results show that the proposed w BRB decoder provides good tradeoff between error performance and throughput for the codes with relatively large column degrees or high rates.
基金supported by the Polish Ministry of Science and Higher Education funding for statutory activities (decision no. 8686/E-367/S/2015 of 19 February 2015)
文摘The non-binary(NB) Irregular Repeat Accumulate(IRA) codes, as a subclass of NB LDPC codes, potentially have an excellent error-correcting performance. They are also known to provide linear complexity of encoding, but the basic encoding method with the serial rate-1 accumulator significantly limits the encoder throughput. Then the objective of the research presented in this paper is to develop an encoding method pro- viding significantly increased throughput of an NB-IRA encoder altogether with a flexible code construction methods for the structured(S-NB-IRA) codes eligible for the proposed encoding method. For this purpose, we reformulate the classic encoding algorithm to fit into the partial parallel encoder architecture. We propose the S-NB-IRA encoder block diagram and show that its estimated throughput is proportional to the submatrix size of the parity check matrix, which guarantees a wide complexity- throughput tradeoff. Then, in order to facilitate the S-NB-IRA coding systems design, we present a computer search algorithm for the construction of good S-NB-IRA codes. The algorithm aims at optimizing the code graph topology along with selecting an appropriate non-binary elements in the parity check matrix. Numerical results show that the constructed S-NB-IRA codes significantly outperform the binary IRA and S-IRA codes, while their performance is similar to the best unstructured NB-LDPC codes.
文摘为解决导航电文信息速率制约导航系统性能的问题,提出了一种基于码移键控调制和多进制低密度奇偶校验码的新型全球卫星导航系统（GNSS）信号编码调制技术.在-130 d Bm的接收电平、误码率不大于10-7的指标下,该技术可以达到1 500 bit/s的有效信息速率,并且具有信号结构简单、与现有GNSS信号兼容性强等优势.理论分析和仿真结果证明,该技术突破了现有卫星导航信号体制下的信息速率极限,能够克服复杂信号结构造成的难以独立捕获跟踪的问题,在卫星导航系统中有比较重要的实用价值.
文摘空间光通信技术是传输高速语音图像等数据信息的重要手段,为了解决星地激光通信系统中大气湍流效应的影响问题,提出一种低译码复杂度的多进制低密度奇偶校验(LDPC)码结合脉冲位置调制(PPM)的传输方案。所构造的多进制LDPC码不仅具有准循环特性,在硬件上易于用移位寄存器实现,且可以根据PPM的调制阶数灵活构造多进制LDPC码,优化系统级联结构。仿真结果表明,在弱湍流信道下此类码具较好的误码性能和较低的错误平层。在SER=10-6时,相比于基于GF(29)的RS(511,305)码,码率为0.88的多进制LDPC码约有4.75 d B的净编码增益。
