重量分布式约束的LDPC码性能研究  

Performance Study of LDPC Codes Constrained by Weight Distribution Polynomials

作　　者：姚春光[1] 张健 葛新 王建新 

机构地区：[1]国防科技大学电子科学与工程学院,湖南长沙410073 [2]中国电子设备系统工程总公司,北京100039

出　　处：《电子学报》2007年第11期2135-2139,共5页Acta Electronica Sinica

摘　　要：本文对"重量分布式约束的码集合内码性能"这一命题进行了初步研究,分别得到了码集合性能的上限和下限,本文给出了性能下限码的Fill-Shift构造方法,而且由LDPC码校验矩阵不变性可以对LDPC码的校验矩阵作必要的初等变换,这样可以在保持码性能不变的前提下降低编码复杂度和实现系统编码;此外,还可以利用该性质加强对重要信息符号的差错保护.Research on LDPC codes is in the ascendant nowadays.Our paper has done some work on the proposition of＂performance of different codes in the same family constrained by weight distribution polynomials＂.Different codes of the same weight distribution are listed,and the results indicate the upper performance bound is determined by density evolution theory and the lower performance bound by the Fill-Shift construction method.Furthermore,the codes in the set of elementary matrix transformation share the same error-correction performance but different coding complexity.We can get a conclusion that codes constrained by weight distribution polynomial can be divided into many groups,performance among different groups is not the same,it depends on the loops length and distribution,and performance in the same group is identical.What we can do now is that to find the best group and do suitable transformations if given weight distribution polynomials.Through this paper,we can see that a new idea for code constructing is also presented.If the relations between big girth of LDPC codes and weight distribution polynomial are discovered, new codes can be achieved only by the weight distribution polynomial,the currently used method given in references for code constructing will be less useful.We can think that we have found a completely different method to construct LDPC codes.

关 键 词：LDPC码 密度进化 码集合 初等变换 重量分布式 

分 类 号：TN911.22[电子电信—通信与信息系统]