欧氏几何准循环LDPC码构造方法改进

为降低短环对低密度奇偶校验(low-density parity-check,LDPC)码迭代译码性能的影响,提出一种改进的基于欧氏几何的准循环LDPC码构造方法。利用已有的欧氏几何方法构造出不含4环的大矩阵,统计其中的短环分布并逐步将参与短环数最多的行和列删除,使构造出的准循环LDPC码包含较少的短环,从而降低短环对迭代译码性能的影响。仿真结果表明,与已有欧氏几何LDPC码相比,改进方法构造的LDPC码具有更少的短环,可获得更好的纠错性能。

An improved design of quasi-cyclic LDPC codes based on Euclidean geometry

In order to solve the problem that short cycles degrade the iterative decoding perform- ance of low-density parity-check （LDPC） codes, an improved method for constructing quasi-cyclic LDPC codes based on Euclidean geometry is proposed. Based on the structural properties of Eu- clidean geometry, a large sparse matrix without 4-cycles is designed, and then the rows and col- umns related to the maximum number of short cycles are deleted after analyzing the distribution of short cycles. The improved method can construct quasi-cyclic LDPC codes with less short cycles, and therefore reduce the influence of short cycle to the effectives of iterative decoding. Sim- ulation results show that the new codes with less short cycles can perform better than the existing Euclidean geometry LDPC codes.