LEO卫星通信系统覆盖时间和切换次数分析

针对近地轨道(LEO)卫星移动通信系统，该文提出一种分析不同用户覆盖时间及切换次数的方法。在充分考虑地面用户随机分布特性的基础上，建立了卫星和波束对随机用户的覆盖时间统计模型，推导了星间切换及波束间切换平均次数下限值的计算方法。最后通过铱星通信系统模型(包括铱星星座参数，地面站参数和阵列天线波束模型)对该方法进行了仿真分析，结果显示该方法能很好地近似用户随机覆盖时间统计特性及平均切换次数的下限值。

Analysis of Coverage Time and Handoff Number on LEO Satellite Communication Systems

This paper presents an approach for analysis of coverage time and handoff number on the mobile LEO satellite communication systems, which fully reflects the random distribution characteristics of the users. Based on the distribution of the user locations, the statistical models of coverage time on satellites and beams are proposed, and the lower bound calculations of the expected number on inter-beam handoff and inter-satellite handoff are derived. Simulation results demonstrate the effectiveness of the proposed algorithms, based on the Iridium communication systems model including the parameters of constellation and earth station, the model of the multi-beam array antennas.