Analysis Method for Downlink Co-Frequency Interference in NGSO Satellite Communication Systems With Information Geometry

The rapid expansion of mega Non-Geostationary Orbit (NGSO) constellation systems has aggravated downlink co-frequency interference (CFI) problem. This work proposes an interference analysis method based on the "distance to center" (DTC) of manifold to analyze CFI in NGSO constellation systems. We establish the manifold geometric structure and parametric characterization model for the probability distribution of the downlink CFI between NGSO systems. The performance of the proposed method under two metrics, Affine Invariant Riemannian Metric (AIRM) and Symmetric Kullback-Leibler Divergence (SKLD), in scenarios involving potential interference from two NGSO satellites is analyzed through simulation, and compared with traditional energy-based method. The results show that the proposed method can effectively mitigate the complexity of interference analysis caused by the time-varying characteristics of NGSO constellations. Additionally, by mining high-dimensional information from signals, interference can be rapidly and accurately analyzed, which provides a novel and efficient method for the analysis of the CFI between NGSO constellation systems and system link design. Finally, the interference signals received by NGSO Earth station are visualized in 3D space by affine embedding method, which can provide an intuitive reference for interference analysis between NGSO systems.