基于移动卫星星座系统的海洋通信关键技术研究

当前，因基于移动卫星星座系统的海洋通信具备重大战略价值，已成为世界各国竞相发展的核心信息技术之一。但其仍面临物理层噪声干扰等参数范围大及变化快等困难，链路层非中心化流量控制与负载均衡不易等问题，及网络层最优路由选择困难等挑战。面对这些难题，本项目拟开展基于稀疏概率图信号处理框架的海空数据链分布式跨层协同中继传输关键技术研究：分布式中继转发低密度奇偶校验码性能预测与高效构造；空间复杂衰落参数的稀疏认知识别与迭代信道估计；互信息累积广义多中继协同信号检测；软概率消息中继存储传递与跨层负载均衡等基础理论及其软硬件实验验证技术。其创新为：分布式码片级联的稀疏图随机预测及码字构造；软概率消息协作传递，消除非联合通信模块的外信息处理损失；多中继协同互信息累积传递，实现低复杂高效可靠迭代消息的快速认知检测；联合跨层多中继存储转发及负载均衡与优化。预期成果有助于促进我国空海数据链战略基础设施的完善和发展。

Nowadays, due to be possessed with significant strategic values, mobile satellite constellation system based marine communications have become one of the core information technologies, which are racing to be developed by all nations in the world. But there are still several problems as follows. First of all, there are difficulties of large range and quick variation parameters, such as noise and interference and so on, in the physical layer. Then, the problems of the decentralized data traffic control, load equalization and so on in the data link layer are also very hard. In addition, the challenges of the optimized route selection in the network layer are formidable too. Confronted with these difficult problems, this project will investigate key technologies of the sparse probability graph signal processing framework based distributed cross-layer coordinated relay transmission in marine-space data links. The research contents are as follows. It mainly investigates the performance prediction and efficient construction of the distributed relay forwarding low-density parity-check (LDPC) codes, the sparse cognitive identification of the space complex fading parameters and the iterative channel estimation, mutual information accumulation based generalized coordination signal detection in the multiple relays, the soft probability message propagation by the buffer aided relays and the cross-layer load equalization and some other related fundamental theories and the related software and hardware experimental verification technologies. The innovations of this project are listed as follows. The concatenations of the distributed and fragmented code words are randomly predicted and optimally constructed by sparse graphs. By means of soft probability metric propagation, the coordinated decoding and signal detection can be use to eliminate the mutual information loss, which mainly occurs in traditional communication and information systems without joint processing. Also the efficient mutual information accumulations based coordination message transmission via multiple relays is applied to accomplish fast cognitive detection of the iterative messages with low complexity, high efficiency and good reliability. The joint cross-layer store-and-forward, the load equalization and optimization in the multiple relays are also employed to improve the transmission efficiency. Finally, the anticipated research fruits of this project will help promote the perfection and development of the space-ocean data link strategic infrastructure in our country.