Multi-carrier based UAV data relaying and user tracking system

Abstract

In the case of natural disaster or emergency rescue, unmanned aerial vehicle (UAV) can be dispatched to the target region and leveraged as aerial relay to track and serve users owning to flexible maneuverability and fast deployment. In this article, a multi-carrier based UAV data relaying and user tracking system is proposed in which the UAV adopts multi-carrier transmission and builds a communication connection from the reliable infrastructure to the target region in emergency. More specifically, a base station (BS) sends information to the UAV which can allocate sub-carriers to users, and then the UAV forwards information, tracks and serves users to ameliorate system performance. A downlink average achievable sum rate maximization-based joint optimization problem, including the UAV flight path, sub-carrier transmit power and user scheduling, is formulated with the information causality constraint. Since the formulated problem suffers from non-convexity, a three-step iterative algorithm is derived to approximate the optimal solution to the original problem by alternatively optimizing UAV flight path, sub-carrier transmit power and user scheduling. Simulation results show that the proposed algorithm can not only track mobile users dynamically, but also demonstrate the performance superiorities of the proposed scheme prominently.