一组高效LDPC码空间通信方案设计与实现

Design and implementation of an efficient LDPC coding scheme for space communication

对基于欧氏几何的QC-LDPC码的数学基础进行了分析与阐述,从原理上分析了此类LDPC码性能优异的原因,并结合CCSDS所推荐的适用于近地通信的(8160,7136)码,建立了此类LDPC码的普适性构造方法。针对航天任务中资源、功耗、码速率的严格要求,设计了一套完备的空间通信编码方案,采用移位寄存累加电路单元(SRAA),分别设计针对面积优化的串行编码电路和针对速度优化的并行编码电路。使用Xilinx Virtex-4 FPGA测试串行编码速率可达210 Mbps以上,并行编码速率最高可达2 Gbps左右。

The mathematical basis of QC-LDPC codes based on Euclidean geometry is analyzed and elaborated in this paper,and the reasons for its excellent performance is analyzed from the perspective of principle.Combined with the （8160,7136） code recommended by CCSDS for near-earth communication,the universal construction method is put forward for this kind of codes.For the stringent requirements of resources,power dissipation and coding rates in space missions,a complete space communication encoding scheme is designed.Using a shift-register-adder-accumulator （SRAA）,a serial encoding circuit for area opfimizaton and a parallel encoding circuit for speed optimization are designed respectively.Tested by Xilinx Virtex-4 FPGA,the serial coding rate can reach 210Mbps and the maximum parallel coding rate can reach 2Gbps.