一种适用于深空通信的有限随机性喷泉码算法

摘要

基于数字喷泉的编译码技术无码率、不需要反馈的特点可适应深空环境下的文件传输.但传统的喷泉随机编码算法需要104量级以上的码长以保证可恢复概率,且原有的译码算法是一种次优方案,无法满足功率和存储空间严格受限的深空通信系统.提出了一种限制编码过程中部分随机性的相关列补偿编码算法,采用渐增高斯消去算法优化译码性能.仿真结果表明所提出的联合优化编译码方案能使码长不大于103的喷泉码在冗余度小于0.20的情况下,获得10-4的译码失败率,较好地解决了传统数字喷泉码在空间通信系统中的适用问题.%A digital fountain-based technique with the advantages of failure rateless and non-feedback is applied to file delivery in the deep space communication. However, a traditional fountain-based algorithm is not suitable for the deep space communication systems with power and storage space limited equipments, for the algorithm, it needs long code length of 104 to obtain the considered recovery probability in encoding stage, and its decoding algorithm is a sub-optimum scheme. In this paper, a new approach, dependent sequences compensation algorithm ( DSCA) is proposed by restricting the randomness in fountain encoding with code-length range of 103. Additional, the incremental Gaussian elimination is adopted to optimize decoding performance. The results show that the joint optimized method can obtain a decoding failure rate of 10-4 under redundancy of 0.20, thus efficiently solving constraints on deep space applications.