Error Propagation Mitigation in Sliding Window Decoding of Spatially Coupled LDPC Codes
Error Propagation Mitigation in Sliding Window Decoding of Spatially Coupled LDPC Codes
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DOI：
10.1109/jsait.2023.3312656
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发表时间：
2023
期刊：
影响因子：
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通讯作者：
Min Zhu;David G. M. Mitchell;M. Lentmaier;Daniel J. Costello
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文献类型：
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作者：
Min Zhu;David G. M. Mitchell;M. Lentmaier;Daniel J. Costello
研究了空间耦合低密度奇偶校验码（SC-LDPC）滑动窗口译码（SWD）的译码器误差传播问题。这个问题通常表现在低延迟操作条件下接近容量的信噪比（SNR）处。在这种情况下，有时会发生不频繁但严重的解码器错误传播。为了帮助理解SC-LDPC码SWD中的错误传播问题，建立了一个多状态马尔可夫模型来描述解码器的行为，并分析了SC-LDPC码在这些条件下的错误性能。然后，我们提出了两种方法--校验节点（CN）掺杂和可变节点（VN）掺杂--来对抗解码器错误传播并提高解码器性能。接下来，我们将描述如何通过采用一种自适应方法，取决于一个无噪声的二进制反馈信道的可用性，可以进一步提高性能。为了说明掺杂技术的有效性，我们使用多状态解码器模型分析CN掺杂和VN掺杂的错误性能。然后，我们提出的计算机模拟结果表明，CN和VN掺杂显着提高在感兴趣的操作范围内的性能，在一个小的速率损失的成本和自适应掺杂进一步提高了性能。我们还表明，速率损失总是小于编码器终止所产生的，并可以进一步减少掺杂只有一小部分的VN在每个掺杂位置的代码图中的性能只有很小的影响。最后，我们展示了如何VN掺杂的编码问题可以大大简化掺杂系统位，很少或没有性能损失。
In this paper, we investigate the problem of decoder error propagation for spatially coupled low-density parity-check (SC-LDPC) codes with sliding window decoding (SWD). This problem typically manifests itself at signal-to-noise ratios (SNRs) close to capacity under low-latency operating conditions. In this case, infrequent but severe decoder error propagation can sometimes occur. To help understand the error propagation problem in SWD of SC-LDPC codes, a multi-state Markov model is developed to describe decoder behavior and to analyze the error performance of SC-LDPC codes under these conditions. We then present two approaches - check node (CN) doping and variable node (VN) doping - to combating decoder error propagation and improving decoder performance. Next we describe how the performance can be further improved by employing an adaptive approach that depends on the availability of a noiseless binary feedback channel. To illustrate the effectiveness of the doping techniques, we analyze the error performance of CN doping and VN doping using the multi-state decoder model. We then present computer simulation results showing that CN and VN doping significantly improve the performance in the operating range of interest at a cost of a small rate loss and that adaptive doping further improves the performance. We also show that the rate loss is always less than that resulting from encoder termination and can be further reduced by doping only a fraction of the VNs at each doping position in the code graph with only a minor impact on performance. Finally, we show how the encoding problem for VN doping can be greatly simplified by doping only systematic bits, with little or no performance loss.