一类girth-8QC-LDPC码构造方法的简化和扩展  

Simplification and Extension of a Class of Girth-eight QC-LDPC Codes

作　　者：张国华[1] 刘智娟[1] 王鸣涛[1] 

机构地区：[1]中国空间技术研究院西安分院,西安710000

出　　处：《空间电子技术》2015年第4期30-34,共5页Space Electronic Technology

基　　金：国家自然科学基金项目(项目编号:61471294)

摘　　要：围长(girth)较大的QC-LDPC码,由于译码性能优良而且便于硬件实现,因此目前已经成为国际信道编码领域的一个研究热点。最近,J-W Zhang在第四届多媒体信息网络与安全国际会议上提出了一种构造girth-8(3,L)QC-LDPC码的新方案,但是没有对围长特性和分块矩阵尺寸取值进行理论分析和论证。利用等价变换和最大公约数体系,本文得到了该方案的围长特性和分块矩阵尺寸取值的精确理论结果。此外,还利用最大公约数体系对该方案进行了扩展,得到一种新的围长为8的QC-LDPC码。新码的参数选取范围包含很多原方案不适用的参数选择范围。仿真结果说明,新码在和积译码算法下具有较优良的译码性能。Quasi-cyclic （QC） low-density parity-check （LDPC）codes with large girth have recently attracted an in- creasingattention, since they have low encoding complexityand generally outperform random LDPC codes for short tomoderate block lengths. Recently,J-W Zhang presented a new class of （3, L） QC-LDPC codes in the 4th international conference on MINS and claimed that such codes have a girth at least eight. However,the proof of the girth property and the method to se- lect the CPM size are not provided. In this paper,it is proved that J-W Zhang＇s method is only a special case of the GCD method. By this observation, an elegant proof for the girth property and the method to select the CPM size are given. Moreo- ver, by extending J - W Zhangg method using the GCD method, a new type of QC-LDPC codes with girth eight are obtained.

关 键 词：低密度奇偶校验码 准循环 围长 最大公约数 

分 类 号：TN911.22[电子电信—通信与信息系统]