高误码率下基于随机抽取的LDPC码校验矩阵重建  

Reconstruction of LDPC code check matrix based on random extraction at high bit error rate

作　　者：王忠勇[1] 李正豪 巩克现 孙鹏[1] 李清涛 WANG Zhongyong;LI Zhenghao;GONG Kexian;SUN Peng;LI Qingtao(School of Electrical and Information Engineering,Zhengzhou University,Zhengzhou 450001,China;61818 Forces,Wuhan 430000,China)

机构地区：[1]郑州大学电气与信息工程学院,河南郑州450001 [2]61818部队,湖北武汉430000

出　　处：《通信学报》2023年第3期128-137,共10页Journal on Communications

基　　金：国家自然科学基金资助项目(No.61901417);河南省科技攻关基金资助项目(No.212102210173,No.212102210566);国家重点研发计划基金资助项目(No.2019QY0302)。

摘　　要：为改善高误码率下LDPC码稀疏校验矩阵重建算法的性能,提出了接收码字个数充足和不充足条件下容错能力较强的校验矩阵开集识别算法。首先,通过多次随机抽取码字的部分比特构建新的码字空间,在较低维度下利用高斯消元法求解对偶向量并还原出校验向量;其次,利用该校验向量,采用“剔除错误码字”或“翻转最低不可靠位”的方法不断提高接收数据内无误码码组的比例进行迭代处理。仿真结果表明,所提算法在不同误码率、不同码长、不同码率、不同码字个数下均优于对比算法。对于IEEE 802.11n协议下的(648,324)LDPC码,当接收码字个数充足时,所提算法在误码率为0.003的条件下,其校验矩阵重建率能达到95%以上;当接收码字个数不足(码字个数为450)时,所提算法在误码率为0.0015的条件下,其校验矩阵重建率能达到90%以上。In order to improve the performance of the sparse check matrix reconstruction algorithm of LDPC codes at high BER,an open set recognition algorithm of the check matrix with strong fault tolerance under the condition of sufficient and insufficient number of received code words was proposed.Firstly,a new code word space was constructed by randomly extracting part bits of the code words for many times.Gaussian elimination method was used to solve the dual vector and restore the check vector in a lower dimension.Secondly,using the check vector,the proportion of error-free code groups in the received data was continuously increased by using the methods of“eliminating error code words”or“flipping the lowest unreliable bits”for iterative processing.Simulation results show that the proposed algorithm is superior to comparison algorithm under different bit error rates,different code lengths,different code rates and different number of code words.For(648,324)LDPC codes in IEEE 802.11n protocol,when the number of received code words is sufficient,the reconstruction rate of check matrix can reach more than 95%under the condition of bit error rate of 0.003.When the number of received code words is insufficient(the number of code words is 450),the reconstruction rate of check matrix can reach more than 90%under the condition of bit error rate of 0.0015.

关 键 词：LDPC 稀疏校验矩阵 高斯消元 剔除错误码字 对数似然比 

分 类 号：TN92[电子电信—通信与信息系统]