An Improved Gradient Descent Bit-Flipping Decoder for LDPC Codes
An Improved Gradient Descent Bit-Flipping Decoder for LDPC Codes
复制标题
一种改进的LDPC码梯度下降位翻转解码器
DOI：
10.1109/tcsi.2019.2909653
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发表时间：
2019-08-01
影响因子：
5.1
通讯作者：
Wang, Zhongfeng
中科院分区：
文献类型：
--
作者：
Cui, Hangxuan;Lin, Jun;Wang, Zhongfeng
低复杂度和高性能的低密度奇偶校验（LDPC）译码器在各种现代通信和存储系统中具有很高的需求。本文提出了一种新的硬判决译码算法--禁忌表随机惩罚梯度下降比特翻转（TRGDBF）算法。与现有的硬判决算法相比，TRGDBF算法通过几个算法改进，具有更好的纠错性能。首先，一个随机惩罚项被引入到反函数中，以帮助解码器逃离陷阱集，这是错误平层现象的主要原因。第二，采用禁忌表来提高解码效率。数值结果表明，TRGDBF算法的纠错性能比概率梯度下降位翻转（PGDBF）算法提高了两个数量级，平均迭代次数减少了约15%。此外，一个良好的优化的硬件架构开发，以实现TRGDBF算法。在硬件设计中，采用了结构转换和结构优化的方法来降低硬件复杂度和延迟.综合结果表明，TRGDBF解码器可以工作在更高的频率和提供更大的吞吐量比PGDBF解码器。
Low-complexity and high-performance low-density parity-check (LDPC) decoders are highly demanded in various modern communication and storage systems. In this paper, a novel hard-decision decoding algorithm, called tabu-list random-penalty gradient descent bit-flipping (TRGDBF) algorithm, is proposed. Compared to the state-of-the-art hard-decision algorithms, the TRGDBF algorithm has much better error-correction performance due to several algorithmic improvements. First, a random-penalty term is introduced to the inversion function to help the decoder escape from trapping sets, which are the main causes of the error-floor phenomenon. Second, a tabu-list is employed to improve the decoding efficiency. Numerical results show that the TRGDBF algorithm can achieve up to two orders of magnitude better error-correction performance than the probabilistic gradient descent bit-flipping (PGDBF) algorithm and reduce the average iteration count by about 15%. In addition, a well-optimized hardware architecture is developed to implement the TRGDBF algorithm. Algorithmic transformation and architecture optimization are well explored to reduce the hardware complexity and latency. Synthesis results show that the TRGDBF decoder can work at a higher frequency and offer a larger throughput than the PGDBF decoder.