Joint Trajectory and Resource Allocation Design for Throughput Optimization in UANET

Natural disasters and some emergencies may destroy the fixed communication infrastructures, and bring great inconvenience to information exchange among people. Unmanned aerial vehicles (UAVs) technology has attracted research interest and has made remarkable progress in recent years because of its great flexibility. In this paper, we propose a framework where UAVs act as temporary air base stations, and provide periodic internal communications for several user groups. We optimize their trajectories such that a weighted function of the minimal throughput is maximized. Firstly, we proposed a distributed gradient-based algorithm to find the optimal hovering positions for UAVs, which can improve the total throughput of each group. Then, we solved a mixed integer linear programming problem to determine the path of each available UAV. Through Shannon-Hartley Theorem, the system optimization objective is formulated by signal-to-noise ratio (SNR) that incorporates with UAV positions and ground user positions. UAVs will be arranged with reasonable paths and hovering time to increase the system throughput. Finally, simulation results verified the effectiveness of the proposed algorithm.