Construction and Decoding of Rate-Compatible Globally Coupled LDPC Codes
Construction and Decoding of Rate-Compatible Globally Coupled LDPC Codes
复制标题
速率兼容全局耦合 LDPC 码的构造和解码
DOI：
10.1155/2018/4397671
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发表时间：
2018
影响因子：
--
通讯作者：
Huaan Li
中科院分区：
文献类型：
--
作者：
Ji Zhang;Baoming Bai;Xijin Mu;Hengzhou Xu;Zhen Liu;Huaan Li
提出了一类速率兼容（RC）全局耦合低密度奇偶校验（GC-LDPC）码，该码采用代数构造法和图扩展相结合的方法构造。具体地说，最高速率码是使用代数方法构造的，较低速率码是通过连续扩展较高速率码的图来形成的。所提出的码率兼容码在保证代数构造的结构特性的同时，提供了更大的码率灵活性。通过AWGN信道下的数值仿真，证实了所提出的码比经典方法构造的GC-LDPC码具有更好的性能，并且在很宽的速率范围内具有近似均匀的容量差距。在此基础上，提出了一种改进的GC-LDPC码两阶段局部/全局迭代译码方案。数值结果表明，该译码方案在低信噪比和中等信噪比时，可以减少局部译码器不必要的开销，而在高信噪比时，不增加全局译码器的译码迭代次数.
This paper presents a family of rate-compatible (RC) globally coupled low-density parity-check (GC-LDPC) codes, which is constructed by combining algebraic construction method and graph extension. Specifically, the highest rate code is constructed using the algebraic method and the codes of lower rates are formed by successively extending the graph of the higher rate codes. The proposed rate-compatible codes provide more flexibility in code rate and guarantee the structural property of algebraic construction. It is confirmed, by numerical simulations over the AWGN channel, that the proposed codes have better performances than their counterpart GC-LDPC codes formed by the classical method and exhibit an approximately uniform gap to the capacity over a wide range of rates. Furthermore, a modified two-phase local/global iterative decoding scheme for GC-LDPC codes is proposed. Numerical results show that the proposed decoding scheme can reduce the unnecessary cost of local decoder at low and moderate SNRs, without any increase in the number of decoding iterations in the global decoder at high SNRs.