一种兼顾卫星导航系统星间观测及通信的链路分配算法

A Link Assignment Algorithm Applicable to Crosslink Ranging and Data Exchange for Satellite Navigation System

卫星导航系统星间采用点波束建立星间链路时,由于星上波束数量小于可建立星间链路的卫星数量,因此便产生了如何有效分配有限波束来建立星间链路的问题。针对该问题首先利用星座运行的周期性提出了一种适用于星间观测及星间通信的拓扑处理方式,并以该拓扑处理方式为基础提出了一种链路分配算法。算法在保证星间观测数量最大化的前提下,以降低整网通信代价为优化目标,尽管为了保证星间观测数量会不可避免地导致通信性能的部分损失,但是仿真结果表明算法的性能整体上优于铱星系统所采用的网状链路分配方法的性能。

In satellite navigation system,satellites can transmit spot beam signals to fulfill crosslink ranging and communication.Because the number of transceivers on board is limited,each satellite has less number of transceivers than its visible satellites.It is necessary to solve how to assign these transceivers to point other satellites effectively in order to meet the both requirements for crosslink ranging and data exchange.A topology model for both requirements is proposed in this paper.Based on the topology model,a link assignment algorithm is designed to maximize the quantity of crosslink ranging information periodically and to improve the communication performance of inter-satellite network simultaneously.Although some communication performance loss is inevitable to perform link assignment for crosslink ranging,the simulation results show that the algorithm gives better communication performance than mesh-link assignment adopted in Iridium system.