空间耦合量子LDPC码的双窗口滑动译码  

Double windows sliding decoding of spatially-coupled quantum LDPC codes

作　　者：王云江 朱高辉 杨宇霆 马钟 魏璐 石莎 WANG Yunjiang;ZHU Gaohui;YANG Yuting;MA Zhong;WEI Lu;SHI Sha(School of Telecommunications Engineering,Xidian University,Xi’an 710071,China;Guangzhou Institute of Technology,Xidian University,Guangzhou 510555,China;Xi’an Microelectronics Technology Institute,Xi’an 710065,China)

机构地区：[1]西安电子科技大学通信工程学院,陕西西安710071 [2]西安电子科技大学广州研究院,广东广州510555 [3]西安微电子技术研究所,陕西西安710065

出　　处：《西安电子科技大学学报》2024年第1期11-20,共10页Journal of Xidian University

基　　金：国家自然科学基金(61771377);陕西省重点研发计划项目(2023-YBGY-206,2020ZDLGY08-06);广东省自然科学基金(2023A1515010671)。

摘　　要：量子纠错码是应对量子计算过程中不可避免的噪声干扰的关键途径。和其经典情形一样,空间耦合量子LDPC码理论上也可在纠错性能和译码时延间取得良好的均衡。考虑到目前采用常规置信传播算法(BPA)的空间耦合量子LDPC(SC-QLDPC)码在译码过程中仍存在复杂度高和译码时延长的问题,受经典滑窗译码算法的启发,并结合和利用SC-QLDPC码所对应的两个奇偶校验矩阵在主对角线和副对角线上具有非零对角带的结构特点,提出了针对量子SC-QLDPC码的滑窗译码算法(称为量子双窗口滑动译码算法)。在该策略中,通过窗口在两个经典校验矩阵主副对角线上的同时滑动,保证了相应量子比特部分译码所需的相位与比特翻转错误图样信息的提取,从而使其在译码性能和时延之间取得良好均衡。对所提量子双窗口滑动译码算法进行仿真验证,结果表明其不仅能提供灵活的低时延译码输出,并且当窗口扩大时,其译码性能逼近标准的量子置信传播算法,显著提升了SC-QLDPC码的应用范围。Quantum error-correcting codes are the key way to address the issue caused by the inevitable noise along with the quantum computing process.Spatially coupled quantum LDPC codes,as their classical counterparts,can achieve a good balance between the error-correcting capacity and the decoding delay in principle.By considering the problems of high complexity and long decoding delay caused by the standard belief propagation algorithm(BPA)for decoding the spatially coupled quantum LDPC codes(SC-QLDPCs),a quantum version of the sliding decoding scheme,named the double window sliding decoding algorithm is proposed in this paper.The proposed algorithm is inspired by the idea of classical sliding window decoding strategies and by exploiting the non-zero diagonal bands on the principal and sub-diagonals structure of the corresponding two parity-check matrices(PCMs)of the concerned SC-QLDPC.The phase and bit flipping error syndromes of the received codeword are obtained by sliding the two windows along the principal and sub-diagonals of the two classical PCMs simultaneously,which enables a good trade-off between complexity and decoding delay to be obtained by using the proposed strategy,with numerical results given to verify the performance of the proposed double window sliding decoding scheme.Simulation results show that the proposed algorithm can not only offer a low latency decoding output but also provide a decoding performance approaching that of the standard BPA when enlarging the window size,thus improving the application scenarios of the SC-QLDPC significantly.

关 键 词：LDPC码 空间耦合 量子码 双窗口滑动 BP译码 

分 类 号：TN911.22[电子电信—通信与信息系统] O413[电子电信—信息与通信工程]