基于EXIT图的PCGC码子码校验矩阵研究及仿真分析

Study on Parity Check Matrix of Parallel Concatenated Gallager Code Based on EXIT Chart and Its Simulation Analysis

传统的PCGC(Parallel Concatenated Gallager Code,并行级联Gallager码)在设计子码时主要依据子码的MCW(Mean Column Weight,平均列重)参数,没有考虑信息节点的度分布的影响。利用基于互信息的EXIT(Extrinsic Information Transfer,边信息转移)图工具,通过计算机仿真,分析获得子码输出增益曲线,并通过构造迭代轨迹来对比分析校验矩阵信息节点度分布对译码性能的影响。仿真结果表明,传统的LDPC(Low Density Parity Check,低密度奇偶校验)码校验矩阵设计的设计准则在PCGC子码设计中并不适用。

The sub-code design of the conventional Parallel Concatenated Gallager Code （PCGC） usually depends on the Mean Column Weigh （MCW） parameters of the sub-code,but does not consider the distribution of the information nodes. The decoding trajectory was constructed and the influence of the sub-code parameters on the decoding performance was analyzed based on the performance gain curves obtained through the EXIT （Extrinsic Information Transfer） chart via computer simulation. The simulation results and the comparison of several PCGC codewords prove the theory analysis conclusion drawn from EXIT chart analysis.