一种基于二次扩展的准循环类RA码编码器的设计

Design of Quasi-cyclic RA-like Codes Based on Expansions through Two Steps

利用RA码易于实现线性复杂度编码的特点,提出了一种新的类RA码的编码器设计方法。该编码器设计方案基于一种特殊的二次扩展的方法,构造的校验矩阵H具有准循环结构,节省校验矩阵存储空间,对码长和码率参数的设计具有高度的灵活性。该编码器的编码算法利用迭代计算求校验位的值,编码器算法复杂度与码长成线性关系,易于编码。计算机仿真结果表明,在加性高斯白噪声信道条件下,该编码方案能取得与Mackay随机码相当甚至更好的性能。

A new design of encoder was proposed for RA-like codes which take the advantage of the linear encoding complexity characteristic of RA codes. The method is based on special expansions through two steps. The code is quasicyclic to save required memory, and has high flexibility with respect to the design of code length and rate. The encoding algorithm is based on reeursions, so the encoding complexity is linear equation of code length. Simulation results demonstrate that over an additive white gauss noise channel, the new codes using expansions by two steps show a bit error rate performance comparable to the random Mackay LDPC codes or even better.