摘要
短环是影响低密度校验码迭代译码性能的重要因素.利用树结构展开的思想,通过分析无效短环和重复短环对计数结果的影响,得出了低密度校验码的一个短环计数公式.利用这一公式,提出了一种基于树结构展开的Tanner图短环计数算法,可对任意给定长度的短环进行计数,从而克服了现有短环计数算法仅能对特定长度短环计数的缺点.对一些典型低密度校验码的短环数量统计结果表明这种算法的正确性.
Short cycles have an important influence on iterative decoding for low-density parity-check(LDPC) codes.By using tree expanding of Tanner graphs and the analysis of the influence of invalid cycles and duplicate cycles,a formula for counting short cycles of LDPC codes is derived.With the derived formula,an algorithm for counting short cycles of Tanner graphs based on tree expanding is proposed.The proposed algorithm can count short cycles with arbitrary lengths,and thus overcomes the disadvantage of existing algorithms that count short cycles with given lengths.Numerical results of counting short cycles of some typical LDPC codes show the correctness of the proposed algorithm.
出处
《西安电子科技大学学报》
EI
CAS
CSCD
北大核心
2010年第2期311-314,共4页
Journal of Xidian University
基金
综合业务网理论及关键技术国家重点实验室开放基金资助项目(ISN10-04)
国家自然科学基金资助项目(60573034)
关键词
低密度校验码
TANNER图
短环
树结构展开
low-density parity-check(LDPC) codes
Tanner graph
short cycles
tree expanding