Analysis of coexistence of non-terrestrial networks and terrestrial networks in adjacent channels

Abstract To enable the coexistence of Non-Terrestrial Networks (NTN) and Terrestrial Networks (TN) within shared geographical areas, this paper presents a comprehensive study on adjacent-frequency interference and compatibility between these systems in the 2 GHz band. Through systematic simulation and analysis, we evaluate the mutual interference effects and identify key challenges for spectrum sharing. First, a comprehensive system model that integrates both NTN and TN architectures is formulated. Subsequently, the Monte Carlo method is adopted to build a system-level simulation platform, focusing on four typical interference scenarios. Simulation results reveal the following key findings: For the scenario of NTN UL interfering with TN UL, NTN UE under power classes PC3, PC2, PC1.5, and PC1 must satisfy ACLR values greater than 24.8 dB, 28.2 dB, 32.9 dB, and 37.5 dB, respectively. In the scenario where the TN UL interferes with the NTN UL, the NTN Satellite Access Node must satisfy ACS values greater than 43 dB, 39.2 dB, 37.4 dB, and 36 dB respectively, corresponding to the NTN UE operating under power classes PC3, PC2, PC1.5, and PC1.In the scenario of TN DL interfering with NTN DL, NTN UE in cell-edge areas requires an ACS greater than 47.5 dB to ensure coexistence. Notably, coexistence for NTN DL interfering with TN DL requires an NTN satellite access node ACLR of less than 10 dB. Compared with existing studies, the novelty of this work lies in that specific radio frequency parameter thresholds and targeted interference mitigation strategies have been systematically derived for four typical coexistence scenarios. These results fill the research gap where existing studies either focus only on single interference scenarios or lack explicit and actionable parameter recommendations, and thus critical technical support is provided for the integrated deployment of NTN and TN in the 2 GHz band.