An improved parallel weighted bit-flipping（PWBF） algorithm is presented. To accelerate the information exchanges between check nodes and variable nodes, the bit-flipping step and the check node updating step of the ...An improved parallel weighted bit-flipping（PWBF） algorithm is presented. To accelerate the information exchanges between check nodes and variable nodes, the bit-flipping step and the check node updating step of the original algorithm are parallelized. The simulation experiments demonstrate that the improved PWBF algorithm provides about 0. 1 to 0. 3 dB coding gain over the original PWBF algorithm. And the improved algorithm achieves a higher convergence rate. The choice of the threshold is also discussed, which is used to determine whether a bit should be flipped during each iteration. The appropriate threshold can ensure that most error bits be flipped, and keep the right ones untouched at the same time. The improvement is particularly effective for decoding quasi-cyclic low-density paritycheck（QC-LDPC） codes.展开更多
Belief propagation list(BPL) decoding for polar codes has attracted more attention due to its inherent parallel nature. However, a large gap still exists with CRC-aided SCL(CA-SCL) decoding.In this work, an improved s...Belief propagation list(BPL) decoding for polar codes has attracted more attention due to its inherent parallel nature. However, a large gap still exists with CRC-aided SCL(CA-SCL) decoding.In this work, an improved segmented belief propagation list decoding based on bit flipping(SBPL-BF) is proposed. On the one hand, the proposed algorithm makes use of the cooperative characteristic in BPL decoding such that the codeword is decoded in different BP decoders. Based on this characteristic, the unreliable bits for flipping could be split into multiple subblocks and could be flipped in different decoders simultaneously. On the other hand, a more flexible and effective processing strategy for the priori information of the unfrozen bits that do not need to be flipped is designed to improve the decoding convergence. In addition, this is the first proposal in BPL decoding which jointly optimizes the bit flipping of the information bits and the code bits. In particular, for bit flipping of the code bits, a H-matrix aided bit-flipping algorithm is designed to enhance the accuracy in identifying erroneous code bits. The simulation results show that the proposed algorithm significantly improves the errorcorrection performance of BPL decoding for medium and long codes. It is more than 0.25 d B better than the state-of-the-art BPL decoding at a block error rate(BLER) of 10^(-5), and outperforms CA-SCL decoding in the low signal-to-noise(SNR) region for(1024, 0.5)polar codes.展开更多
当前美国国家标准与技术研究院(National Institute of Standards and Technology,NIST)对后量子密码(Post-Quantum Cryptography,PQC)标准化方案的评估已进入第四轮,位翻转密钥封装(Bit Flipping Key Encapsulation,BIKE)协议是目前被...当前美国国家标准与技术研究院(National Institute of Standards and Technology,NIST)对后量子密码(Post-Quantum Cryptography,PQC)标准化方案的评估已进入第四轮,位翻转密钥封装(Bit Flipping Key Encapsulation,BIKE)协议是目前被评估的四个候选方案之一.在BIKE的密钥生成算法中,多项式乘法作为众多密码系统中特别耗时的操作之一,耗费了大量的时间和面积资源.针对此问题,本文设计了一种基于Karatsuba算法(Karatsuba Algorithm,KA)的无交叠多项式乘法器,可高效实现万级比特位宽的多项式乘法,具有低时延、高性能和面积小的特点.同时,本文将该优化乘法器应用于BIKE密钥生成算法中,并基于现场可编程门阵列(Field Programmable Gate Array,FPGA)对其进行硬件架构实现,改进了原有的紧凑多项式乘法和多项式求逆算法.本文提出的乘法器通过采用不同的操作数位宽,可适应对面积和延时的不同需求.与BIKE原本的设计相比,改进的设计使密钥生成模块的延时减小了36.54%,面积延迟积(Area Delay Production,ADP)减小了10.4%.展开更多
以信息节点的幅度和作为校验方程的可靠度信息,提出两种简单高效的低密度奇偶效验(low density parity check,LDPC)码的加权比特翻转(weighted bit flipping,WBF)译码算法。仿真结果表明,在加性高斯白噪声信道下,误比特率为10-5时,相比...以信息节点的幅度和作为校验方程的可靠度信息,提出两种简单高效的低密度奇偶效验(low density parity check,LDPC)码的加权比特翻转(weighted bit flipping,WBF)译码算法。仿真结果表明,在加性高斯白噪声信道下,误比特率为10-5时,相比于传统的WBF和改进型WBF(modified WBF,MWBF)算法,提出的一种算法可分别获得约1.65dB和1.31dB的增益。同时,平均迭代次数也大大降低。展开更多
该文提出一种改进的低密度奇偶校验(Low Density Parity-Check,LDPC)码的加权比特翻转译码算法。该算法引入了变量节点的更新规则,对翻转函数的计算更加精确,同时能够有效弱化环路振荡引起的误码。仿真结果表明,与已有的基于幅度和的加...该文提出一种改进的低密度奇偶校验(Low Density Parity-Check,LDPC)码的加权比特翻转译码算法。该算法引入了变量节点的更新规则,对翻转函数的计算更加精确,同时能够有效弱化环路振荡引起的误码。仿真结果表明,与已有的基于幅度和的加权比特翻转译码算法(SMWBF)相比,在加性高斯白噪声信道下,该文算法在复杂度增加很小的情况下获得了误码率性能的有效提升。展开更多
针对串行抵消列表翻转(Successive Cancellation List Flip,SCLF)译码算法存在译码性能与复杂度不能同时兼顾的问题,提出了一种快速串行抵消列表翻转(Fast Successive Cancellation List Flip,FSCLF)译码算法。该算法通过加入四种特殊...针对串行抵消列表翻转(Successive Cancellation List Flip,SCLF)译码算法存在译码性能与复杂度不能同时兼顾的问题,提出了一种快速串行抵消列表翻转(Fast Successive Cancellation List Flip,FSCLF)译码算法。该算法通过加入四种特殊结点的识别来加快译码速率,同时构建了临界集(Critical Set,CS),不再依据先前译码错误而引起的错误传播,而是通过两种特殊结点即信息比特R1结点和单奇偶校验(Single-Parity-Check,SPC)结点分别对对数似然比(LogLikelihood Ratio,LLR)值进行计算来判决并确定翻转位置,当奇偶校验位不满足时只需翻转与最不可靠输入LLR值相对应的信息比特,这样减少了翻转次数,从而降低了算法复杂度。仿真结果表明:在误块率为10-5时,所提出的FSCLF译码算法比原SCLF译码算法的信噪比改善了0.09dB,为中短码长情况提供了参考算法。展开更多
利用统计译码思想由LDPC(Low Density Parity Check)码校验矩阵通过矢量的线性组合构造出一个新的低密度校验矢量集合,并结合LDPC码并行比特翻转译码算法的环检测等特点的分析,提出了一种新的硬判决译码方案。仿真结果表明:改进算法在...利用统计译码思想由LDPC(Low Density Parity Check)码校验矩阵通过矢量的线性组合构造出一个新的低密度校验矢量集合,并结合LDPC码并行比特翻转译码算法的环检测等特点的分析,提出了一种新的硬判决译码方案。仿真结果表明:改进算法在译码性能上接近BP算法,又保持了并行比特翻转算法迭代次数少的优点。展开更多
基金The National High Technology Research and Development Program of China (863Program) ( No2009AA01Z235,2006AA01Z263)the Research Fund of the National Mobile Communications Research Laboratory of Southeast University(No2008A10)
文摘An improved parallel weighted bit-flipping（PWBF） algorithm is presented. To accelerate the information exchanges between check nodes and variable nodes, the bit-flipping step and the check node updating step of the original algorithm are parallelized. The simulation experiments demonstrate that the improved PWBF algorithm provides about 0. 1 to 0. 3 dB coding gain over the original PWBF algorithm. And the improved algorithm achieves a higher convergence rate. The choice of the threshold is also discussed, which is used to determine whether a bit should be flipped during each iteration. The appropriate threshold can ensure that most error bits be flipped, and keep the right ones untouched at the same time. The improvement is particularly effective for decoding quasi-cyclic low-density paritycheck（QC-LDPC） codes.
基金funded by the Key Project of NSFC-Guangdong Province Joint Program(Grant No.U2001204)the National Natural Science Foundation of China(Grant Nos.61873290 and 61972431)+1 种基金the Science and Technology Program of Guangzhou,China(Grant No.202002030470)the Funding Project of Featured Major of Guangzhou Xinhua University(2021TZ002).
文摘Belief propagation list(BPL) decoding for polar codes has attracted more attention due to its inherent parallel nature. However, a large gap still exists with CRC-aided SCL(CA-SCL) decoding.In this work, an improved segmented belief propagation list decoding based on bit flipping(SBPL-BF) is proposed. On the one hand, the proposed algorithm makes use of the cooperative characteristic in BPL decoding such that the codeword is decoded in different BP decoders. Based on this characteristic, the unreliable bits for flipping could be split into multiple subblocks and could be flipped in different decoders simultaneously. On the other hand, a more flexible and effective processing strategy for the priori information of the unfrozen bits that do not need to be flipped is designed to improve the decoding convergence. In addition, this is the first proposal in BPL decoding which jointly optimizes the bit flipping of the information bits and the code bits. In particular, for bit flipping of the code bits, a H-matrix aided bit-flipping algorithm is designed to enhance the accuracy in identifying erroneous code bits. The simulation results show that the proposed algorithm significantly improves the errorcorrection performance of BPL decoding for medium and long codes. It is more than 0.25 d B better than the state-of-the-art BPL decoding at a block error rate(BLER) of 10^(-5), and outperforms CA-SCL decoding in the low signal-to-noise(SNR) region for(1024, 0.5)polar codes.
文摘以信息节点的幅度和作为校验方程的可靠度信息,提出两种简单高效的低密度奇偶效验(low density parity check,LDPC)码的加权比特翻转(weighted bit flipping,WBF)译码算法。仿真结果表明,在加性高斯白噪声信道下,误比特率为10-5时,相比于传统的WBF和改进型WBF(modified WBF,MWBF)算法,提出的一种算法可分别获得约1.65dB和1.31dB的增益。同时,平均迭代次数也大大降低。
文摘该文提出一种改进的低密度奇偶校验(Low Density Parity-Check,LDPC)码的加权比特翻转译码算法。该算法引入了变量节点的更新规则,对翻转函数的计算更加精确,同时能够有效弱化环路振荡引起的误码。仿真结果表明,与已有的基于幅度和的加权比特翻转译码算法(SMWBF)相比,在加性高斯白噪声信道下,该文算法在复杂度增加很小的情况下获得了误码率性能的有效提升。
文摘针对串行抵消列表翻转(Successive Cancellation List Flip,SCLF)译码算法存在译码性能与复杂度不能同时兼顾的问题,提出了一种快速串行抵消列表翻转(Fast Successive Cancellation List Flip,FSCLF)译码算法。该算法通过加入四种特殊结点的识别来加快译码速率,同时构建了临界集(Critical Set,CS),不再依据先前译码错误而引起的错误传播,而是通过两种特殊结点即信息比特R1结点和单奇偶校验(Single-Parity-Check,SPC)结点分别对对数似然比(LogLikelihood Ratio,LLR)值进行计算来判决并确定翻转位置,当奇偶校验位不满足时只需翻转与最不可靠输入LLR值相对应的信息比特,这样减少了翻转次数,从而降低了算法复杂度。仿真结果表明:在误块率为10-5时,所提出的FSCLF译码算法比原SCLF译码算法的信噪比改善了0.09dB,为中短码长情况提供了参考算法。
文摘利用统计译码思想由LDPC(Low Density Parity Check)码校验矩阵通过矢量的线性组合构造出一个新的低密度校验矢量集合,并结合LDPC码并行比特翻转译码算法的环检测等特点的分析,提出了一种新的硬判决译码方案。仿真结果表明:改进算法在译码性能上接近BP算法,又保持了并行比特翻转算法迭代次数少的优点。
