JOURNAL OF ELECTRONICS INFORMATION TECHNOLOGY

An Improvement on the Min-sum Algorithm for Low-rate Protograph LDPC Codes

Ming Jiang, Chen Wang

Published Dec 10, 2010• 0 citations

Abstract

低密度奇偶校验(LDPC)码的译码硬件实现方案大多采用计算复杂度较低的修正最小和(NMS)算法，然而对于低码率LDPC码，由于校验节点度数低，NMS算法的修正误差较大，导致其译码性能和标准的置信传播(BP)算法相比有较大差异。该文针对基于原图构造的一类低码率LDPC码，提出了在NMS迭代译码中结合震荡抵消(OSC)处理和多系数(MF)修正技术的方案。结合低码率原型图LDPC码行重分布差异较大的特点，MF修正算法可以有效地减少计算误差，从而改善译码性能。另外低码率原型图LDPC码的收敛较慢，而OSC处理则可以较好地抑制正反馈信息，进一步提高NMS算法的性能增益。仿真结果表明，对于此类低码率LDPC码， MF-OSC-NMS算法可以达到接近BP算法的性能。OSC处理和MF修正技术硬件实现简单，与NMS算法相比几乎没有增加计算复杂度，因此MF-OSC-NMS算法是译码算法复杂度和性能之间一个较好的折中处理方案。

DOI: 10.3724/sp.j.1146.2009.01652

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