一种速率匹配的准循环LDPC码的编码构造方法

提出了一种新颖的速率匹配的准循环低密度校验码(Low density parity check,LDPC)的编码方法,该方法采用渐进添边(Progressive edge-growth,PEG)算法为工具,综合运用有限几何构造法和搜索方法选取子矩阵的偏移量进行优化,构造LDPC码字,使其生成的校验矩阵具有最短环周期最大化以及短环尽可能少的特点。通过这种方式构造出来的LDPC码,可以实现从1/3~5/6的码率,达到了速率匹配的目的。通过计算机仿真证明,此方法构造的LDPC码字具有良好的误码率和误帧率的性能,并能有效消除LDPC码的"差错地板"现象。并且这种编码方法简单,可节省存储空间,减少编、译码的复杂度。

Construction of Rate-Compatible Quasi-Cyclic LDPC Code

A novel rate-compatible quasi-cyclic low density parity check(LDPC) code is proposed based on progressive edge-growth(PEG) algorithm to optimize the offset of sub matrix through using the finite geometries constructing method and search algorithm.LDPC code has maximum short-ring-cycle and a minimum number of the short rings. Through this method,quasi-cyclic LDPC codes can be obtained with the code-rate range from 1/3 to 5/6.Simulation results demonstrate that LDPC code has good frame error ratio and bit error ratio and also can effectively eliminate the error floor phenomenon.Moreover,with low complexity and small storage space,the code is easy to encode.