Trajectory Design in Rechargeable UAV Aided Wireless Networks: A Unified Framework for Energy Efficiency and Flight Time Minimization

TL;DR

This paper presents a unified framework for designing UAV trajectories in rechargeable wireless networks, optimizing energy efficiency and flight time by jointly considering velocity, power, and hovering positions.

Contribution

It introduces a flow-based mathematical programming model and a two-step optimization method to minimize total operation time in rechargeable UAV-assisted networks.

Findings

Proposed method outperforms existing techniques in reducing total time.

Joint optimization significantly improves energy efficiency.

Numerical results validate the effectiveness of the framework.

Abstract

This paper studies a rechargeable unmanned aerial vehicle (UAV) assisted wireless network, where a UAV is dispatched to disseminate information to a group of ground terminals (GTs) and returns to a recharging station (RS) before the on-board battery is depleted. The central aim is to design a UAV trajectory with the minimum total time duration, including the flight and recharging time, by optimizing the flying velocity, transmit power and hovering positions jointly. A flow-based mathematical programming formulation is proposed to provide optimal for joint optimization of flying and recharging time. Furthermore, to attack the curse of dimensionality for optimal decision making, a two-step method is proposed. In the first step, the UAV hovering positions is fixed and initialize a feasible trajectory design by solving a travelling salesman problem with energy constraints (TSPE) problem. In the second step, for the given initial trajectory, the time consumption for each sub-tour is minimized by optimizing the flying velocity, transmit power and hovering positions jointly. Numerical results show that the proposed method outperforms state of art techniques and reduces the aggregate time duration in an efficient way.