改进的非规则QC-LDPC译码算法和结构  

Improved Decoding Algorithm and Structure of Irregular QC-LDPC

作　　者：陈发堂[1] 王永航 张翰卿 CHEN Fa-tang;WANG Yong-hang;ZHANG Han-qing(School of Communication and Information Engineering,CUPT,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

出　　处：《光通信研究》2020年第6期1-4,16,共5页Study on Optical Communications

基　　金：国家科技重大专项资助项目(2017ZX03001021)。

摘　　要：为提升非规则准循环低密度奇偶校验码的译码性能和降低译码器实现难度,文章提出了一种基于度数归一化最小和(BD-NMS)算法和一种改进的译码结构。首先分析了最优归一化因子变化规律,得到其在不同度数下的分布特性,依据分布特性对度数分层,最后利用密度演化和加权向量得到各层归一化因子。文章所提译码结构中,校验节点以提升值为单位分组,每组以2的整数次幂为单位分子层,子层按顺序依次更新。仿真结果与复杂度分析表明,文章所提译码结构资源消耗和复杂度更低;BD-NMS算法拥有更为优异的译码性能和收敛速度,在误码率为10-6时译码性能比密度演化最小和(DE-MS)算法提升了0.19 dB左右,增加的复杂度只包括比较运算,易于硬件实现。In order to improve the decoding performance of the irregular Quasi Cyclic Low Density Parity Check(QC-LDPC)code and reduce the implementation difficulty of the decoder,this paper proposes a Based-Degree Normalized Min Sum(BD-NMS)algorithm and an improved decoding structure.The algorithm first analyzes the changing rule of the optimal normalization factor,and obtains its distribution characteristics in different degrees.According to the distribution characteristics,the degrees can be layered.Finally,the normalization factors of each layer are obtained by density evolution and weighted vector.In the proposed structure,the verification nodes are grouped with the lifting value as the unit,and each group is divided by the integral power of 2 as the unit molecular layer.The sub-layers are then updated in sequence.Simulation results and complexity analysis show that the proposed decoding structure consumes less resources and has lower complexity.It can be seen that the BD-NMS algorithm has better decoding performance with faster convergence speed.The decoding performance is 0.19 dB higher than that of Density Evolution Min-Sum(DE-MS)when the bit error rate is 10-6.It is also concluded that the increased complexity only includes comparison operation,which is easy to implement in hardware.

关 键 词：准循环低密度奇偶校验码 归一化最小和算法 译码结构 

分 类 号：TN911.22[电子电信—通信与信息系统]