面向火星临近空间的分布式中继纠删编码机制研究

火星探测极远的通信距离以及行星遮挡，使得探测车与地面站的通信需要构建火星临近空间网络传输信息。为保证数据传输的可靠性并提高传输效率，重点研究基于分布式前向纠删编码的多个火星探测车通过中继轨道器向地面站传输的场景。考虑探测节点的周期性加入和退出的特性，设计了源节点使用弱鲁棒孤波LT码，中继随机转发/异或的中继随机决策编码方案，并推导了转发概率的理论最优值。仿真验证了新方案与已有的分布式喷泉方案相比，降低了约50%的信源编码开销，并通过复杂度与译码冗余的折衷，达到了99.9%的译码成功率。

Research on Distributed Relay Erasure Codes in Mars Proximity Network

Data transmission from Mars rovers to deep space stations need to be relayed by Mars orbiters and construct a Mars Proximity Network (MPN), due to the extremely far distance and occultation of planets in Mars exploration communications. In order to guarantee the reliability of data communication and enhance the efficiency of data transmission, the sense of multi rovers transmitting data from an orbiter to earth stations is researched based on distributed relay erasure codes. Considering the periodic and frequent arrival and departure of nodes in MPN, a random decision relaying scheme (RDRS) is proposed, in which source nodes are used to generate Weaken Robust Soliton Wave Luby Transform codes, and randomly forward/XOR symbols are relayed from two Source nodes to an earth station. Simulation results show that, both proposed RDRS and improved RDRS schemes can achieve decoding success rate of 99.9% with only encoding overhead of 50% compared with existing distributed fountain code scheme.