窗口可变的空间耦合LDPC码滑窗译码算法  

Sliding window decoding algorithm for spatially coupled LDPC codes with a variable window

作　　者：张娅妹 周林[1,2] 陈辰 郭荣新[1] 贺玉成[1,2] ZHANG Yamei;ZHOU Lin;CHEN Chen;GUO Rongxin;HE Yucheng(Xiamen Key Laboratory of Mobile Multimedia Communications,Huaqiao University,Xiamen 361021,China;State Key Laboratory of Integrated Services Networks,Xidian University,Xi’an 710071,China)

机构地区：[1]华侨大学厦门市移动多媒体通信重点实验室,福建厦门361021 [2]西安电子科技大学综合业务网理论及关键技术国家重点实验室,陕西西安710071

出　　处：《西安电子科技大学学报》2020年第3期128-134,共7页Journal of Xidian University

基　　金：国家自然科学基金(61901182,61302095);福建省自然科学基金(2018J01096);泉州市科技计划(2018C108R);华侨大学研究生科研创新基金(18014082037)。

摘　　要：空间耦合低密度奇偶校验码采用滑动窗口译码能够以较小的译码延迟获得较好的译码性能。为进一步提高其滑窗译码性能,提出一种窗口扩展改进方案。与传统的滑窗译码相比,该方案的窗口大小可以根据目标符号的平均对数似然比而变化。在当前窗口的迭代译码过程中,若目标符号的平均对数似然比小于预设阈值,则译码窗口大小加1后重新进行迭代,重复此过程,直至目标符号满足阈值条件或达到窗口大小的最大值,然后在新的窗口大小下译码目标符号。该方案可以在译码性能、复杂度和延迟之间进行折中权衡。在加性高斯白噪声信道下的仿真结果表明,该方案可以显著提高空间耦合低密度奇偶校验码的滑窗译码性能。Spatially coupled low density parity check(SC-LDPC)codes can achieve a better decoding performance with a small message recovery latency due to the sliding window decoding.An improved decoding scheme based on window extension is proposed for further enhancing the performance of the sliding window decoding.In contrast to conventional sliding window decoding,the window size of this scheme can vary according to the average logarithmic likelihood ratio(LLR)value of the target symbol.Specifically,for every iteration in the decoding process,we compare the average LLR value of the target symbol with the preset threshold.If the average LLR value of the target symbol is less than the preset threshold and the current window size does not exceed the maximum size,the decoding window size adds one and then performs a new iteration with the new window size.By this means,the scheme can achieve trade-off between decoding performance,complexity and latency.Simulation results on the additive white Gaussian noise(AWGN)channel show that this scheme can significantly improve the sliding window decoding performance of SC-LDPC codes.

关 键 词：空间耦合低密度奇偶校验码 滑窗译码 窗口扩展 

分 类 号：TN911.22[电子电信—通信与信息系统]