Cross-Link Interference Modeling in 6G Millimeter Wave and Terahertz LEO Satellite Communications

One of the important questions when discussing next-generation near-Earth mmWave and terahertz (THz) band satellite communications as an integral part of the 5G-Advanced and 6G landscape is the potential interference-related issues when deploying such systems. While the space-to-ground and ground-to-space interference has been explored in multiple works already, the interference at mmWave and THz cross-links, the links between the satellites themselves, have not been extensively studied yet. However, severe cross-link interference may both challenge the reliability of the data exchange within the constellation, as well as compromise the efficient co-existence of multiple satellite constellations (i.e., by different providers) covering the same or neighboring areas. In this paper, both relevant mathematical models and extensive simulation studies are presented for cross-link mmWave and THz satellite communications. Our results indicate that the cross-link interference in the considered setups is a non-negligible factor that must be further explored and accounted for in the design and deployment of next-general mmWave and THz satellite communication systems.