一种优化Girth分布的准循环LDPC码设计方法研究

A Method for Designing Quasi-Cyclic LDPC Codes Based on Girth Optimization

在准循环LDPC码的构造中,校验矩阵拥有尽可能好的girth分布对于改善码的性能有着重要的意义。该文提出了构造准循环LDPC码的GirthOpt-DE算法,优化设计以获得具有好girth分布的移位参数矩阵为目标。仿真结果表明,该文方法得到的准循环LDPC码在BER性能和最小距离上均要优于固定生成函数的准循环LDPC码,Arrary码和Tanner码,并且使用上更为灵活,可以指定码长,码率及尽可能好的girth分布。

The key to improving the performance of QC LDPC codes is how to construct a parity-check matrix H with a girth distribution as good as possible. In this paper, a novel algorithm for constructing QC LDPC codes, GirthOpt-DE algorithm, is proposed, which achieves a good girth distribution based on the differential evolution. Simulation results show that the performance of the QC LDPC codes constructed with the proposed algorithm is superior to Array codes and Tanner codes in both BER and the minimum distance. Besides, the proposed algorithm is more flexible for designing the QC LDPC codes with desired block length and rate as well as good girth.