Optimal position and power allocation for RSMA multigroup multicast and multibeam UAV-assisted communication

Abstract

This paper investigates rate-splitting multiple access (RSMA) under probabilistic line-of-sight (PLoS) links in multigroup multicast and multigroup unmanned aerial vehicle assisted communication network ($M^3$UAVCN), where a UAV transmits messages to several ground multicast groups under the influence of an external jammer. Specifically, we study a joint optimization problem involving the optimal UAV position, transmission power allocation and common rate allocation to maximize energy-efficiency (EE) of the UAV, which is non-convex. To tackle this non-convex problem, we propose a two-tier alternating optimization (AO) algorithm. Firstly, we employ the Block Coordinate Descent (BCD) methodology to decompose the original problem into UAV optimal position subproblem and power-rate allocation subproblem. Then, a particle swarm optimization algorithm with adaptive inertial weight (AIWPSO) is introduced to solve the UAV optimal position subproblem. In order to overcome the non-convexity of power-rate allocation subproblem, the successive convex approximation (SCA) and the slack variables method are used to obtain a suboptimal solution of $M^3$UAVCN. Simulation results demonstrate that our proposed algorithm outperforms space-division multiple access (SDMA) and non-orthogonal multiple access (NOMA) in terms of enhancing EE.