基于广义等差数列的大围长QC-LDPC码构造  

Generalized arithmetic sequence based large-girth QC-LDPC codes construction

作　　者：赵辉[1,2] 余孟洁 安静 邝凯达 吕典楷 ZHAO Hui;YU Meng-jie;AN Jing;KUANG Kai-da;LYU Dian-ka(School of Communication and Information Engineering,Chongqing University of Posts and Telecommunications,Chongqing 400065,China;Chongqing Key Laboratory of Signal and Information Processing,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 [2]重庆邮电大学信号与信息处理重庆市重点实验室,重庆400065

出　　处：《计算机工程与设计》2022年第12期3563-3569,共7页Computer Engineering and Design

基　　金：国家自然科学基金项目(61671095)。

摘　　要：为解决准循环低密度奇偶校验(quasi-cyclic low-density parity-check,QC-LDPC)码中短环严重影响误码率性能的问题,提出一种基于广义等差数列(generalized arithmetic sequence,GAS)的大围长QC-LDPC码构造方法。利用GAS中元素的差值不等性构造QC-LDPC码的循环移位系数矩阵,给出移位系数值的解析公式;提出一种局部优化算法对存在第二类6环结构的码字进行围长优化。该构造方法占用空间小,通过改变解析公式中的参数值可以实现码长和码率的灵活改变。仿真结果表明,与对比文献中提出的码字相比,构造的QC-LDPC码在加性高斯白噪声(additive white Gaussian noise,AWGN)信道上表现出更好的误码率性能。To solve the problem that the short cycles in the quasi-cyclic low-density parity-check(QC-LDPC)code seriously affect the bit error rate performance,a construction method of large-girth QC-LDPC codes based on the generalized arithmetic sequence(GAS)was proposed.The cyclic shift coefficient matrix of the QC-LDPC code was constructed using the difference inequality of the elements in GAS,and the analytical formula of the shift coefficient value was given.A local optimization algorithm was proposed to optimize the girth of the code with the second type of 6-girth cycle structure.This method occupies a small space,and the code length and code rate can be flexibly changed by changing the parameter values in the analytical formula.Simulation results show that,compared with the codes proposed in the comparative literature,the constructed QC-LDPC codes have better bit error rate performance compared to additive white Gaussian noise(AWGN)channels.

关 键 词：准循环低密度奇偶校验码 广义等差数列 短环 围长 局部优化算法 

分 类 号：TN911.22[电子电信—通信与信息系统]