Joint Space Location Optimization and Resource Allocation for UAV-Assisted Emergency Communication System

In the emergency communication scenario, how to quickly collect ground users (GUs) information and carry out reliable transmission has become a difficult point. In this paper, we consider the unmanned aerial vehicle (UAV)-assisted emergency communication system based on uplink non-orthogonal multiple access (NOMA). For the considered system, an alternative optimization scheme for the space location of UAV and resource allocation is proposed to maximize the uplink throughput from the UAV to base station (BS). The original joint optimization problem turns out to be non-convex and is divided into two sub-problems. Firstly, we optimize the space location of UAV by using particle swarm optimization algorithm, which has significant advantages in solving the optimal space location problem. Secondly, by using the tools of the first-order Taylor expansion and successive convex approximation, we jointly optimize the bandwidth allocation coefficients and transmit powers of GUs to maximize the throughput from the UAV to BS. Finally, simulation results verify our proposed scheme is superior in terms of the throughput for UAV-assisted emergency communication system compared with the existing scheme and the baseline schemes.