结合CRC校验的LDPC码后处理译码算法  

Post-processing decoding algorithm for LDPC codes with CRC checking

作　　者：陈紫强[1] 王广耀[1] CHEN Ziqiang,WAN G Guangyao(School of Information and Communication,Guilin University of Electronic Technology,Guilin 54 1004, Chin)

机构地区：[1]桂林电子科技大学信息与通信学院,广西桂林541004

出　　处：《桂林电子科技大学学报》2018年第1期1-6,共6页Journal of Guilin University of Electronic Technology

基　　金：国家自然科学基金(61461015);广西自然科学基金(2014GXNSFAA118399);广西教育厅科研项目(ZD2014052)

摘　　要：为了改善低密度奇偶校验码的错误平层,提出一种结合循环冗余校验位的分层置信传播(cyclic redundancy check layered belief-propagation,简称CRC-LBP)后处理算法。对LBP译码的判决结果执行CRC校验,若校验失败,则对错误帧中变量节点的后验对数似然比值从小到大排序。从排序的节点序列中选取前若干个目标节点组成坏节点集,翻转BN集内信息节点的初始LLR值,并继续译码直至CRC校验成功,打破潜在陷阱集,提高节点可靠度。仿真实验结果表明,在增加少量存储空间的代价下,CRC-LBP算法具有更低的错误平层。In order to mitigate the error-floor for LDPC codes,a layered belief-propagation post-processing algorithm with cyclic redundancy check was proposed.CRC checking was done at the end of each iteration for LBP decoding,if CRC checking failed,the posteriori logarithm likelihood ratios of variable nodes in the erroneous frames were sorted in ascending orders.Then the several former target nodes from the ordered nodes sequence were selected to form bad nodes set,each initial LLR value for decoded information bits in BN set was flipped and the decoding was done continuously until CRC succeeded,so as to break the potential trapping sets and improve the reliability of variable nodes.The simulation results demonstrate that the CRC-LBP algorithm has lower error-floor at the expense of little extra memory space.

关 键 词：LDPC码 循环冗余校验位 错误平层 分层置信传播 陷阱集 

分 类 号：TN911.22[电子电信—通信与信息系统]