基于软信息的CCSDS标准RS码识别算法

Recognition Algorithm of CCSDS Standard RS Code Based on Soft Information

针对实际工程应用中的里德-所罗门(Reed-Solomon,RS)编码识别问题,根据国际空间数据系统咨询委员会(Consultative Committee for Space Data Systems,CCSDS)标准,提出了基于软信息的低复杂度缩短交织RS编码识别算法。利用码字同步算法对码字起点和缩短长度进行识别,利用接收到的RS码字计算基于校正子后验概率对数似然比平均值的编码识别特征,对码字的交织深度进行识别;进而利用识别所得的RS码交织深度和缩短长度对接收码字进行解交织和码字填充,识别RS码生成多项式。仿真结果表明,所提算法在信噪比为6.1 dB时正确识别概率即可大于90%,相较传统硬判决识别算法和基于伽罗华域快速傅里叶变换(Galois Field Fourier Transform,GFFT)的谱累积量算法均有显著的性能提升。

To solve the recognition problem of Reed-Solomon(RS)code from the CCSDS standard,a low complexity recognition method of shortened interleaving RS code based on soft information is proposed.Firstly,the starting point and shortened length of RS code are recognized by using codeword synchronization algorithm.Then the average log-likelihood ratio of syndrome posterior probability is calculated as the identification feature by the received RS codeword.Thus the interleaving depth of RS code is recognized.Then,the received codeword is deinterleaved and padded according to the recognized interleaving depth and shortened length of RS code.Finally,the generator polynomial of RS code is recognized.The simulation results show that when the signal to noise ratio is 6.1 dB,the recognition accuracy can reach more than 90%.The performance of the proposed equivalent binary soft information recognition algorithm is better than that of the equivalent binary hard decision recognition algorithm and the spectral cumulant algorithm based on Galois Field Fourier Transform(GFFT).