基于改进型LBP译码的LDPC码稀疏校验矩阵重建  

Reconstruction of LDPC code sparse check matrix based on modified LBP decoding

作　　者：张天骐[1] 李春运 吴仙越 吴云戈 ZHANG Tianqi;LI Chunyun;WU Xianyue;WU Yunge(School of Communication and Information Engineering,Chongqing University of Posts and Telecommunications,Chongqing 400065,China)

机构地区：[1]重庆邮电大学通信与信息工程学院,重庆400065

出　　处：《通信学报》2024年第5期70-79,共10页Journal on Communications

基　　金：重庆市自然科学基金资助项目(No.cstc2021jcyj-msxmX0836)。

摘　　要：针对LDPC码稀疏校验矩阵重建问题,基于改进型LBP译码的思想提出了一种高误码率下的LDPC码稀疏校验矩阵重建算法。首先,从码字矩阵中随机抽取部分比特构建码字分析矩阵,并对其做高斯消元求对偶空间;其次,通过判定对偶空间向量是否稀疏,提高了后续疑似校验向量判定的效率;最后,在接收码字个数不足时,利用已知校验向量结合改进型LBP译码方法纠正错误码字,加快LDPC码稀疏校验矩阵的重建速度,提高重建性能。仿真结果表明,所提算法在高误码率0.0045的条件下,对于IEEE802.11n协议下的(648,324)LDPC码,相比于现有算法,稀疏校验矩阵重建率提升了52.16%,可达到92.28%。In order to reconstruct the sparse check matrix of LDPC code,a sparse check matrix reconstruction algorithm for LDPC code at high BER was proposed based on modified LBP decoding.Firstly,some bits were selected randomly from the codeword matrix to construct the codeword analysis matrix,and Gaussian elimination on it was performed to find the dual space.Secondly,by determining whether the pairwise space vectors were sparse or not,it improved the effi‐ciency of the subsequent suspected check vectors determination.Finally,in the case of insufficient received codes,the known check vectors were combined with the modified LBP decoding method to correct the wrong codes,so as to speed up the reconstruction of the sparse check matrix of LDPC code and improve the reconstruction performance.The simula‐tion results show that the reconstruction rate of sparse check matrix of(648,324)LDPC codes in IEEE 802.11n protocol is improved by 52.16%compared with the existing algorithms,and can reach 92.28%at high BER of 0.0045.

关 键 词：低密度奇偶校验码 稀疏校验矩阵 高斯消元 改进型LBP译码 重建 

分 类 号：TN92[电子电信—通信与信息系统]