Implementation Of High-speed Codec For LDCP Codes In Satellite Communication

The rapid development of satellite communication brings great convenience to the human communication.Nevertheless,satellite communication requires a channel coding scheme with high coding gain in time-varying channels.At the same time,satellite communication requires large throughput in an age of “big data”.Two classes of Low-density parity-check codes in CCSDS standard stand out from numerous channel coding schemes.Therefore,from a practical standpoint,this thesis will focus on the rate-compatible and high-speed implementation of LDPC codes for deep space communication and for near-earth satellite communication,respectively.First of all,the rate-compatible implemention for the AR4JA-LDPC codes in CCSDS standard is realized.Different codes are selected according to channel conditions to ensure the reliability of communication as well as increasing the transmission rate.In this thesis,the sum product decoding algorithm and the min-sum decoding algorithm of nine LDPC codes in the code group are simulated.As a result,the rate-compatible implementation can achieve better hardware resource reuse efficiency in the encoder and decoder.The throughput of nine LDPC codes is able to reach 19.79Mbps~82.16 Mbps.Secondly,the(8176,7154)LDPC code in CCSDS standard is implemented with high-throughput encoder and decoder on the Xilinx Virtex 6 platform.The original parity-check matrix is converted into a block quasi-cyclic LDPC code which is easy to be implemented at high speed with negligible loss of decoding performance.In the encoder,the highest throughput is 1.52 Gbps and the stable throughput is 1.025 Gbps with only 4% resources consumption.In the decoder,the highest throughput is 913.3Mbps and the stable throughput is 764.89 Mbps with 15% resource consumption.Finally,for(5120,4096)LDPC code in CCSDS standard,the high-throughput implementation for the encoder and decoder is realized on the Xilinx Virtex 6 platform.In the encoder,the encoding parallelism is increased to eight times by using eight bits parallel coding and the highest throughput is 1.704 Gbps and the stable throughput is 1.2Gbps with only 2% resource consumption.In the decoder,the matrix splitting strategy of the parity-check matrix is studied,and the parallelism of the original part of the parallel decoding is increased to four times of the original code.The highest throughput is 771.32 Mbps and the stable throughput is 569.94 Mbps with 37% resource consumption.