Optimized Resource Allocation for RSMA in Beam-Hopping Multicast LEO Satellite Network

Low earth orbit (LEO) multi-beam satellites have the characteristics of high capacity and high spectral efficiency, providing geographically independent services to ground users. However, the use of frequency reuse technologies leads to increasing inter-beam interference. Rate-splitting multiple access (RSMA), a novel multiple access technology, decomposes messages into common and private parts, effectively reducing interference. This makes RSMA highly promising for multibeam satellite scenarios. Therefore, this paper investigates the resource allocation problem of RSMA in the beam-hopping multicast LEO satellite network. The aim is to minimize the gap between traffic demand and achievable rates while meeting user latency requirements. To solve this problem, it is decomposed into two subproblems. First, considering user latency constraints, the beam scheduling problem is modeled as a potential game to determine the beam hopping pattern (BHP). Then, for the power allocation and rate matching problem, auxiliary variables are introduced to convert it into a convex problem, which is solved using the successive convex approximation (SCA) method. The simulation results confirm that this method performs better than the baseline approaches of Spatial Division Multiple Access (SDMA) and Orthogonal Frequency Division Multiple Access (OFDMA).