面向硬件实现的64进制LDPC译码算法研究与性能评估  

Research and Performance Evaluation of 64-ary LDPC Decoding Algorithm for Hardware Implementation

作　　者：树玉泉 章林锋 胡志蕊 刘轶龙 贡冀鑫 SHU Yuquan;ZHANG Linfeng;HU Zhirui;LIU Yilong;GONG Jixin(The 54th Research Institute of CETC,Shijiazhuang 050081,China;Unit 32021,PLA,Beijing 100094,China)

机构地区：[1]中国电子科技集团公司第五十四研究所,河北石家庄050081 [2]中国人民解放军32021部队,北京100094

出　　处：《无线电工程》2022年第4期657-663,共7页Radio Engineering

基　　金：国家自然科学基金(91638203)。

摘　　要：北斗三号全球卫星导航系统下行信号中使用了64进制低密度奇偶校验码(Low Density Parity Check,LDPC)作为主要的信道编码形式,64进制LDPC译码复杂度较高,为接收机译码模块的硬件实现带来了挑战。针对这一问题,在传统扩展最小和(EMS)算法的基础上面向接收机硬件实现,提出了一种优化的译码算法。该算法在校验节点的运算中应用了前向后向-检泡(FB-BC)流水线处理方案,并对校验节点-变量节点间的变量传递存储机制进行了优化,降低了译码复杂度和硬件资源开销。针对(200,100)(162,81)(96,48)(88,44)四种编码长度,开发了参数可配置的四合一译码模块,搭建了软硬件测试环境,对北斗三号64进制LDPC的性能进行了仿真评估,提出了满足接收机需求的译码参数组合。验证结果表明,译码模块主要硬件资源占用仅占FPGA(XC7K325T)的5%,在60 MHz时钟、5 bit量化、10次迭代时,译码增益可以达到7 dB,同时吞吐率优于50 ks/s,可满足北斗三号接收机使用需求。The Beidou-3 system uses 64-ary LDPC as the main channel coding scheme for downlink signals.The complexity of 64-ary LDPC decoding brings challenges to the hardware implementation of receiver’s decoding module.In response to this problem,an optimized decoding algorithm based on traditional Extended Minimum Sum(EMS)algorithm is proposed for receiver hardware implementation.The algorithm uses an FB-BC pipeline processing scheme in the operation of check node,and optimizes the variable transfer and storage mechanism between the check node and the variable node,which reduces the decoding complexity and hardware resource occupation.For the four encoding lengths of(200,100)(162,81)(96,48)(88,44),a four-in-one decoding module with configurable parameters is developed,and a software and hardware test environment is built.The performance of the LDPC system is fully simulated and evaluated,and a combination of decoding parameters that meets the needs of the receiver is proposed.The results show that the main hardware resource occupation of the decoding module is only 5%of FPGA(XC7K325T).With a 60 MHz clock,5 bit quantization,and 10 iterations,the decoding gain can be up to 7 dB,and the throughput rate is better than 50 ks/s,which meets the requirements of Beidou-3 receiver.

关 键 词：卫星导航 北斗三号系统 64进制LDPC 接收机 译码增益 

分 类 号：TN967.1[电子电信—信号与信息处理]