基于随机几何的低轨星座下行通信链路仿真与分析

Simulation and Analysis of Downlink Communication Links in Low Earth Orbit Constellations Based on Stochastic Geometry

低轨卫星网络具有低成本、大容量、广覆盖的特性,是未来空天地海一体化网络中的重要支柱和6G网络的关键组成部分,开展链路分析对于低轨星座链路设计与优化具有重要意义。由于低轨卫星移动性强、星地电磁环境复杂、链路较长等特点,星地信息传输与传统地面移动通信有着显著差异。根据低轨星座的特性构建星座网络的随机几何BPP模型,并针对低轨星座空间分布及移动特征,分析了单星及多星场景下的损耗、干扰等对星地通信链路的影响。通过给出星座系统干扰期望计算方法,并基于所构建BPP网络对星地通信链路特性进行仿真。仿真结果表明,构建随机几何的基于BPP分布的星座模型可以很好地模拟卫星网络的状态,采用随机几何对低轨星座下行通信链路进行仿真分析,能够得到更具泛化的星座构型下低轨星座对地面站的干扰情况,为巨型低轨星座网络分析及星地链路设计提供了参考。

Low Earth Orbit(LEO)satellite networks,characterized by their low cost,high capacity,and wide coverage,are an important pillar in the future space-air-ground-sea integrated networks,and a key component of 6G networks.Link analysis is vital for the design and optimization of LEO constellation links.Due to the strong mobility of LEO satellites,the complexity of the satellite-terrestrial electromagnetic environment,and the extended length of links,satellite-terrestrial information transmission significantly differs from traditional terrestrial mobile communications.This paper constructs a random geometric Binomial Point Process(BPP)model for constellation networks based on the characteristics of LEO constellations.It analyzes the impact of loss and interference on satellite-terrestrial communication links in single and multiple satellite scenarios,considering the spatial distribution and mobility features of LEO constellations.By providing a method for calculating the expected interference in constellation systems and simulating the satellite-terrestrial communication link characteristics based on the constructed BPP network,the simulation results demonstrate that the constellation model based on BPP distribution in random geometry can effectively simulate the state of satellite networks.Simulating and analyzing the downlink communication links of LEO constellations using random geometry yields more generalized results for the interference scenarios of LEO constellations to ground stations under various constellation configurations,offering valuable insights for the analysis of large-scale LEO constellation networks and the design of satellite-terrestrial links.