Low-Complexity Dynamic Beam Placement Optimization Methods for LEO Satellite Multicast Communications

In this letter, we investigate a beam placement optimization problem for low Earth orbit (LEO) satellite multicast communication systems aiming at finding the best beam center to maximize the minimal rate of multiple ground nodes (GNs). We develop two methods to solve this problem: the optimization-based method and the smallest enclosing disk on a sphere (SEDS)-based method. Numerical results demonstrate that the proposed algorithms exhibits better performance compared to the state-of-the-art geometry-based algorithm with computational complexities scaling only linearly with the number of GNs.