利用完备差集构造QC-LDPC码  

Constructing QC-LDPC Codes by Using Perfect Difference Families

作　　者：袁建国[1] 李媛媛[1] 梁梦琪 尚晓娟[1] 王永[1] 

机构地区：[1]重庆邮电大学光通信与网络重点实验室,重庆400065

出　　处：《电讯技术》2016年第5期471-475,共5页Telecommunication Engineering

基　　金：国家自然科学基金资助项目(61472464);重庆市基础与前沿研究计划项目(cstc2015jcyj A0554)~~

摘　　要：针对准循环低密度奇偶校验(QC-LDPC)码中循环置换矩阵的移位次数的确定问题,提出了一种利用组合设计中完备差集(PDF)构造QC-LDPC码的新颖方法。当循环置换矩阵的维度大于一定值时,该方法所构造的规则QC-LDPC码围长至少为6,具有灵活选择码长和码率的优点,且所需的存储空间更少,降低了硬件实现的复杂度。仿真结果表明:在误码率为10-5时,所构造的码率为3/4的PDF-QC-LDPC(3136,2352)与基于最大公约数(GCD)构造的GCD-QC-LDPC(3136,2352)码和基于循环差集(CDF)构造的CDF-QC-LDPC(3136,2352)码相比,其净编码增益(NCG)分别有0.41 d B和0.32 d B的提升;且在码率为4/5时,所构造的PDF-QC-LDPC(4880,3584)码比GCD-QC-LDPC(4880,3584)码和CDF-QC-LDPC(4880,3584)码的NCG分别改善了0.21 d B和0.13 d B。For the problem of determining shift times of the circulant permutation matirx( CPM) in quasi-cy-clic low-density parity-check(QC-LDPC) codes,a novel construction method based on the perfect differ-ence family( PDF) among combinatorial mathematics is proposed. When the dimension of the CPM exceeds a certain particular value,the girth of the Tanner graph of QC-LDPC codes constructed by this method is at least six,and the proposed algorithm has high flexibility with respect to the design of code-length and code-rate. In addition,it has less requirement about storage space,so the complexity of the hardware implementa-tion is reduced. The simulation results show that the net coding gain(NCG) of the PDF-QC-LDPC(3136, 2352) code with the code-rate of 3/4 is respectively improved 1. 15 dB and 0. 58 dB than those of the GCD-QC-LDPC(3136,2352) code based on the greatest common divisor(GCD) and the CDF-QC-LDPC(3136, 2352) code based on the cyclic difference family(CDF) at the bit error rate(BER) of 10-5. In addition,the NCG of the proposed PDF-QC-LDPC(4880,3584) code is improved 0. 21 dB and 0. 13 dB than those of the GCD-QC-LDPC(4880,3584) code and the CDF-QC-LDPC(4880,3584) code with the same conditions correspondingly with the code-rate of 4/5 and the BER of 10-5 .

关 键 词：准循环低密度校验码 循环置换矩阵 完备差集 净编码增益 

分 类 号：TN911.22[电子电信—通信与信息系统]