QC-LDPC码最小环路检测算法  

Algorithm for detecting minimum cycles in QC-LDPC codes

作　　者：薛宇丛 周华[1] 铁鑫 XUE Yu-cong;ZHOU Hua;TIE Xin(School of Electronic and Information Engineering,Nanjing University of Information Science and Technology,Nanjing 210044,China)

机构地区：[1]南京信息工程大学电子与信息工程学院,江苏南京210044

出　　处：《计算机工程与设计》2020年第8期2165-2169,共5页Computer Engineering and Design

基　　金：国家自然科学基金项目(61401216)。

摘　　要：在迭代译码过程中,当准循环低密度奇偶校验(quasi-cyclic low-density parity-check,QC-LDPC)码校验矩阵的双向图中存在短环时,译码性能降低。为减少短环的影响,提出一种简便的最小环路检测算法。借鉴比特翻转(bit-flipping,BF)译码算法的思想,遵循逻辑运算规则,将二进制序列在变量节点和校验节点之间迭代交换,能够在较短的时间内得到校验矩阵中最小环路的围长。仿真结果验证了该算法结果的正确性,并验证在相同信噪比下,增加最小环路围长能够改进QC-LDPC码的误码率和误帧率。In the iterative decoding process,the decoding performance decreases when short cycles in the parity-check matrix of quasi-cyclic low-density parity-check codes exist.To reduce the influence of short cycles,a simple minimum cycle detection algorithm was proposed.The algorithm was based on the idea of bit-flipping(BF)decoding algorithm and followed the rules of logic operation.The binary sequences iterated between bit nodes and check nodes.The length of the minimum cycle of the parity-check matrix was obtained in a short time.Simulation results verify the correctness of the algorithm,and also show that the BER and FER of QC-LDPC codes can be improved by increasing the minimum cycle length under the same SNR.

关 键 词：准循环低密度奇偶校验码 最小环路 双向图 循环置换矩阵 误码率 误帧率 

分 类 号：TP301.6[自动化与计算机技术—计算机系统结构]