Resource Allocation with Interference Avoidance in Beam-Hopping Based LEO Satellite Systems

The spectrum sharing between the low earth orbit (LEO) and geostationary earth orbit (GEO) satellite communication systems provides a feasible solution to relieve the spectrum shortage and support the rapid expansion of LEO satellite systems. In order to improve the spectrum efficiency and avoid serious inter-system interference (ISI), we investigate the resource allocation for beam-hopping (BH) based LEO satellite systems which share the spectrum resources with a BH-based GEO satellite. The BH technology enhances the resource scheduling flexibility of the satellite systems, but it also makes the ISI more complicated and intractable. Considering the limited computing capability of the LEO satellite, the resource allocation problem is decomposed into the time slot allocation (TA) sub-problem and the transmit power optimization (TPO) sub-problem. A greedy algorithm is proposed for the TA sub-problem, and the TPO sub-problem is solved by using the convex optimization theory. Simulation results show that the proposed resource allocation scheme not only achieves higher system throughput, but also suppresses the ISI at a low level, which ensures the harmonious coexistence of the two satellite systems.