分离航天器网络动态拓扑构建、优化和传输容量

Representing a novel architecture，fractionated spacecraft is a distributed space system replacing structure with information for earth observation and space exploration in the future, and can be made to react to various forms of uncertainty, ranging from environmental uncertainty, technical uncertainty, launching uncertainty to fluctuations in the acquisition funding stream. And it must have the capability to respond rapidly to these uncertainties by making the spacecraft architecture fundamentally flexible and robust. It requires that the fractionated spacecraft is an autonomous network with cluster flight. As a result, the autonomous network brings a higher requirement to network topology and transmission capacity also. . Facing the fundamental challenges of dynamic time-varying characteristics, J2-perturbed random, storing and forwarding nodes, and intermittent connectivity between nodes, this program will study the network topology and transmission capacity of the autonomous network of the fractionated spacecraft with cluster flight, and solve the key scientific problems about setting the distance-bounded relative motion model with J2 perturbation and computing the connectivity probability based on phase space. Through intensive studying the construction the dynamic topology for the fractionated spacecraft network based on SINR, the optimization and control of network topology based on connectivity, the transmission capacity and its power optimizing control based on SINR, this program will reveal the temporal-spatial evolutionary behaviors of the dynamic network topology, solve some difficult problems about optimizing and controlling the dynamic network topology and the transmission capacity subjecting to limited power for the fractionated spacecraft. Finally, this program will break through some key techniques for the fractionated spacecraft network, and provide theoretical support for building the fractionated spacecraft network.

针对今后对地观测和空间探测存在的技术、环境、发射、需求、投入等不确定性，作为创新性架构，分离航天器是一种信息换结构的分布式空间系统。这种架构要求簇飞行分布式自主网络，对分离航天器网络拓扑和传输容量等提出了更高要求。针对分离航天器网络拓扑高动态时变空变特性，引力场摄动和传输损耗的随机性，模块节点的存储转发特性，节点间连接间歇性等基础性挑战，本项目将开展簇飞行分离航天器网络拓扑构建、优化和传输容量研究，着重解决建立J2摄动下距离有界的相对运动模型和基于相空间的连接概率计算关键科学问题。在深入研究基于SINR模型的分离航天器网络动态拓扑构建、基于连接的网络拓扑优化控制、基于SINR模型的传输容量及功率优化控制等基础上，揭示分离航天器动态网络拓扑时空演化规律，解决功率约束下分离航天器动态网络拓扑优化控制和传输容量优化等难题，突破分离航天器网络一些关键技术，为构建分离航天器网络提供一些理论支撑。

分布式空间系统在军事和经济社会中作用越来越重要，而分离航天器网络因节点间距离相对有界，便于轨道控制而更为引人重视。项目开展了基于SINR模型的分离 航天器网络动态拓扑构、基于连接的分离航天器网络拓扑优化控制、基于SINR模型的传输容量及功率优化控制研究。 围目研究目标，通过引入航天器双星伴飞模式，建立了分离航天器网络节点移动模型，研究了噪声受限网络渗流特性，研究了网络节点路径形成时间和时间常数；通过研究节点间距离分布特性，给出距离的分布的高斯近似，引入序贯路径的概念，定义节点邻接矩阵乘法，深入研究了节点间多跳连接概率和时空演进特性；基于节点间连接特性和距离分布的高斯近似，研究了网络误包率和时延与节点间连接的关系，运用Monte Carlo方法，研究了多QoS的节点发射功率的非凸优化算法和OFDMA网络分布式功率鲁棒性控制方法；通过研究译码转发和放大转发两类节点的中断特性，深入分析了节点单跳和两跳的传输容量特性和控制方法。最后，开发了系统仿真验证平台，提出了簇飞行天基组网雷达的新概念，分析了组网构型对模糊函数的影响。以上工作较好地解决了建立J2摄动下距离有界的相对运动模型和连接概率计算关键科学问题，初步揭示了分离航天器动态网络拓扑的时空演化规律，为构建分离航天器网络提供了一些理论支撑。