We propose a quantized decoding algorithm for low- density parity-check codes
where the variable node update rule of the standard min-sum algorithm is
replaced with a look-up table (LUT) that is designed using an
information-theoretic criterion. We show that even with message resolutions as
low as 3 bits, the proposed algorithm can achieve better error rates than a
floating-point min-sum decoder. Moreover, we study in detail the effect of
different decoder design parameters, like the design SNR and the LUT tree
structure on the performance of our decoder, and we propose some complexity
reduction techniques, such as LUT re-use and message alphabet downsizing.

本文提出了一种用于低密度奇偶校验码的量化解码算法，其中，标准的最小和算法的变量节点更新规则被用信息论准则设计的查找表所替换。研究结果表明，即使使用只有 3 位消息分辨率的算法，也能比使用浮点数的最小和译码器取得更好的误码率；此外，研究了不同的译码器设计参数对译码性能的影响，如设计信噪比和查找表树结构等，并提出了一些复杂度约简技术，如查找表重用和消息字母表缩小。