Geometry-Based Non-Stationary Inter-Large-Satellite Wireless Channel Model

Inter-satellite links are significant to achieve complex space missions like high precision ranging and rendezvous navigation. However, the impact of spacecraft multipath on system performance cannot be ignored, especially for large spacecraft. To evaluate and optimize the satellite communication system, a geometry-based non-stationary inter-large-satellite wireless channel model is proposed. It includes three components, i.e., a line-of-sight component, solar-panel-bounce parts for multipath on solar panels, and body-bounce (BB) components resulting from spacecraft body scattering. The BB clusters' time-variant azimuth angle of arrival and departure are derived because conventional angle distribution functions, like von Mises, are unsuitable for scatterers directionally located in a limited region in satellite scenarios. Channel evolution in the space-time-frequency (STF) domain is modeled with birth-death processes regarding self-rotation and solar panel rotation in addition to three-dimensional (3D) movement. Then, channel characteristics, e.g., STF correlation functions, Doppler power spectrum density, and stationary intervals, are derived and studied. Finally, the proposed channel model is validated to be accurate by ray-tracing simulation, satellite measurement and on-orbit observation.