Robust Spectrum Sharing for 6G NTN-TN Integrated Network with Time-Correlated Channel

The integration of Non-Terrestrial Networks (NTN) and Terrestrial Networks (TN) is a promising solution for 6 G, enabling seamless and ubiquitous connectivity by combining the high data rate capabilities of TN with the extensive coverage of NTN. Spectrum sharing between NTN and TN can significantly improve spectral efficiency but poses challenges related to intersystem interference, especially in fast time-varying NTN channels caused by low Earth orbit (LEO) satellite movement. This paper introduces a novel robust spectrum sharing mechanism that addresses these challenges by dynamically adapting to channel variations and mitigating interference in NTN uplink scenarios. Unlike previous approaches, our method independently manages spectrum sharing mechanisms for NTN and TN, reducing coordination complexity and enhancing system adaptability. By leveraging adaptive bandwidth allocation based on real-time channel conditions, the proposed method ensures efficient radio resource utilization and robust performance. Simulation results show that the robust spectrum sharing mechanism achieves up to a 20% improvement in throughput compared to baseline methods, demonstrating its effectiveness in enabling efficient and robust spectrum sharing for NTN-TN integrated networks.