Spectrum Sharing and Interference Management for 6G LEO Satellite-Terrestrial Network Integration

The rapid emergence of satellite systems introduces unprecedented interference challenges to both existing satellite networks and Terrestrial Networks (TNs), necessitating innovative strategies to efficiently manage spectrum resources amid heightened competition. Traditional interference management methods fail to address the unique challenges facing satellite systems. These challenges include higher propagation delays caused by the high altitude of Low Earth Orbit (LEO) satellites, increased Doppler shifts due to their high speeds, atmospheric attenuations affecting LEO satellite-TN links, and limited processing capacity in satellite systems. This article provides a comprehensive exploration of interference in LEO satellite-Integrated Terrestrial Networks (LITNets), encompassing various types of interference, including Inter-Beam Interference (IBI), which occurs between different beams of the same satellites; Inter-Satellite Interference (ISI), which arises between different satellites; and LEO satellite-Terrestrial infrastructure Interference (LTI). Moreover, it outlines strategies for interference management and reviews current mitigation methods. Finally, the article concludes by discussing the research challenges and proposing future directions for enhancing spectrum efficiency and interference management in LITNets.