Reverse Spectrum Allocation for Spectrum Sharing between TN and NTN

An integrated Non-Terrestrial Network (NTN) and Terrestrial Network (TN) is a promising solution to satisfy the demands for ubiquitous coverage and increased capacity requirements in mobile cellular networks. In this paper, spectrum sharing mechanism and co-channel interference in TN-NTN integrated system are studied. A novel reverse spectrum pairing mechanism is proposed to mitigate the co-channel interference to the NTN service link. A comprehensive analysis of TN interference to NTN satellite receiver under various scenarios with realistic environment settings is presented. The simulation results show that due to the high directivity of base station antennas, the aggregated base station-to-NTN interference in reverse pairing is much lower than the aggregated UE-to-NTN interference in normal pairing. The proposed reverse pairing overwhelms the normal pairing by a 35 dB higher SINR in the service link. NTN UEs with high elevation angles could also enjoy communication services equivalent to cellular networks in reverse pairing. With a lower co-channel interference to the NTN satellite, the reverse spectrum pairing allows the deployment of an integrated TN-NTN with service link spectrum sharing.