面向深空通信的分布式系统Raptor码传输机制

为缓解深空探测器与地面站之间的超远距离和星体遮挡，而导致巨大的信号衰减以及链路频繁中断的问题，基于容迟/容断网络（DTN）协议框架，利用轨道器进行多跳中继组网传输，设计了多个探测器经过轨道器向地面传输场景下的分布式系统Raptor编码传输方案（DSRC）。提出了联合译码简化方案，理论分析推导了DSRC方案及改进方案的性能参数，并与现有分布式无速率纠删方案进行仿真比较，在译码冗余为5%时达到了0.01的译码失败率。

Distributed Systematic Raptor Coding Scheme in Deep Space Communications

In Mars exploration missions, due to the long propagation distance and planet occultation in rovers-to-Earth direct link, data transmission suffers a huge loss and frequent interruptions in connectivity. Based on delay tolerant network (DTN) framework, a distributed systematic Raptor coding (DSRC) scheme is proposed for the multi-hop relay transmission data through an orbiter to Earth communications scenario. A simplified joint decoding scheme is designed, and the asymptotic performance of DSRC scheme is analyzed. Moreover, the improved DSRC scheme is optimized for the finite code-length. Simulation results show that the DSRC scheme can achieve a decoding failure rate of 0.01 with a decoding overhead of 5%, which outperforms the existing distributed rateless erasure codes.