一种抑制短环的LDPC码软件构造方法

An software construction method restricting short girth of LDPC codes

LDPC码是一种具有优秀纠错性能的信道编码方式,已成为第四代通信系统强有力的竞争者.Gallager提出的正则LDPC码中由于编码中短长度圈的存在,编码性能会在某种程度上降低.研究了Tanner图中的短环对编码性能的影响,在Gallager构造方法的基础上,提出一种可抑制长度为4的短环的软件构造方法,通过半随机的方法构造各行位置向量,并检验是否存在长度为4的短环,给出了算法的软件流程图,仿真结果表明:抑制短环的软件方法构造的LDPC码,其误码性能和Gallager构造法相比,误码性能得到了很好的改善.

Low-Density-Parity-Check-Codes（LDPC） taken as a kind of advanced channel coding mode,has become the powerful competitor of the fourth generation communication system.The LDPC advanced by Gallager have standard Tanner figure structure,the performance of coding will fall down in a way because of the existence of short girth in the Tanner figure.It is advanced the improvement of structured method based on Gallager,the short girth that length is 4 was eliminated and the flow chart was given.Simulation result shows that performance of coding is raised.