Collinear Interference Avoidance Strategy for LEO Satellite Constellation Based on Transmit Beamforming

With the concept of air-space-ground network integration proposed, satellite communication systems have rapidly developed as an essential carrier of space networks. Limited by the scarce radio frequency resources, spectrum coexistence between different satellite systems is essential, especially in the collinear scenario between LEO satellites and other systems. This study focuses on modeling and analyzing collinear scenarios, introducing a novel approach by transforming both inter-system and intra-system interference constraints into gain constraints for transmitting beams, and proposing an interference avoidance strategy based on transmitting beamforming. By suppressing interference through beam nulling, the isolation angle can be reduced, thereby expending the serviceable range of satellites. Simulation results validate the effectiveness of the proposed algorithm, showcasing a significant reduction in interference from LEO satellites on other systems. This strategy offers a feasible solution to the coexistence challenges faced by large-scale constellations.