为了研究通信星座服务区域内不同地面用户之间的通信连通情况,提出了网络综合连通度(DCNC)的概念.作为服务可用性(AoS)的重要内容,网络综合连通度应该成为通信系统的一项重要性能评价指标,对系统的顶层设计起到主导作用.首先给出了星座网络综合连通度的相关定义,在此基础上基于星间链路约束和星座覆盖约束建立了LEO移动通信星座的网络综合连通度的评价模型.然后基于该模型,分别改变轨道高度和轨道倾角,就不同星座的网络综合连通度如何变化进行了仿真计算和分析.结果表明,二者都对星座的网络综合连通度有显著影响,适当减少轨道面数有利于改善网络综合连通度.最后研究了星座缺失卫星时不连通地面点的纬度分布情况,研究结论有助于在概念设计阶段对星座构型优化后的参数进行优选.

A concept of degree of comprehensive network connectivity (DCNC) is proposed in order to study the communicational connectivity between different ground users in the service area of a communication constellation. As an important part of availability of service (AoS), DCNC should be a pivotal specification of communicational systems and play a leading role in the top design of systems. First, the relevant definitions of DCNC are proposed, based on which a DCNC evaluation model is established which takes into consideration the inter-satellite link constraints and coverage constraints in a LEO mobile communication constellation. Using the model, simulation and analysis for DCNC variation are performed in different constellations by altering the orbital heights and orbital inclinations respectively. The simulation results indicate that both orbital inclination and orbital height have notable effects on DCNC, and that reducing the number of orbital planes properly is advantageous to the improvement of DCNC. The conclusions can help select the optimal constellation configuration parameters in the concept design phase.