Impacts of Large-Scale NGSO Satellites: RFI and A New Paradigm for Satellite Communications and Radio Astronomy Systems

Large-scale non-geostationary orbit (NGSO) satellite communication systems (SCSs) are gaining interest from industries because of their ubiquitous wireless access and backhaul capabilities. However, the NGSO SCSs’ global downlink transmission can cause radio frequency interference (RFI) to the radio astronomy system (RAS) on earth. Thus, this paper first investigates RFI impacts of a large-scale NGSO SCS. Our RFI analyses show that a large-scale low earth orbit (LEO) SCS completely disrupts RAS’s continuum observation within or adjacent to the SCS downlink bands, which limits coexistence and growths of both SCS and RAS. To overcome such limitation, we propose a new paradigm where SCS and RAS are integrated into the NGSO satellite system, thus effectively creating large-scale telescopes in orbit. This integrated system not only avoids SCS’s RFI to RAS but also offers more spectrum access opportunities to both SCS and RAS. In addition, this paper addresses two related problems of the new paradigm, namely, the spectrum resource allocation problem and the RAS data transport problem. Our performance evaluation illustrates the advantages of the proposed paradigm in terms of accessible spectrum bands, RAS observation performance, and SCS maximum mean supportable data rate as well as enabling coexistence and growths of both types of services.