Spectrum Coexistence of Satellite-borne Passive Radiometry and Terrestrial Next-G Networks

Spectrum coexistence between terrestrial Next-G cellular networks and space-borne passive remote sensing (RS) is now gaining attention. One major question is how would this coexistence impact RS equipment? In this study, we develop a framework based on stochastic geometry to evaluate the statistical characteristics of radio frequency interference (RFI) affecting RS satellites. Specifically, we consider RFI originating from a large-scale terrestrial Next-G network that spans dense urban areas across the globe, where each urban area contains a cluster of cellular base stations (BSs) operating in the same frequency band as the RS satellite. For illustration, we assume that the network operates in the restricted L-band (1400-1427 MHz) with NASA's Soil Moisture Active Passive (SMAP) satellite. We use a Thomas Cluster Process (TCP) to model the distribution of terrestrial BSs and derive the RFI on SMAP's antenna's main-and side-lobes. We show that a large number of active clusters can operate in the restricted L-band without compromising SMAP's mission if they avoid interfering with the main-lobe of its antenna. This is possible thanks to SMAP's extremely low side-lobe antenna gains.