Completion Time Minimization in Wireless-Powered UAV-Assisted Data Collection System

In unmanned aerial vehicle (UAV)-assisted data collection system, UAVs can be deployed to charge ground terminals (GTs) via wireless power transfer (WPT) and collect data from them via wireless information transmission (WIT). In this letter, we aim to minimize the time required by a UAV via jointly optimizing the trajectory of the UAV and the transmission scheduling for all the GTs. This problem is formulated as a mixed integer nonlinear programming (MINLP) which are difficult to address in general. To this end, we develop an iterative algorithm based on binary search and successive convex optimization (SCO) to solve it. The simulation shows that our proposed solution outperforms the benchmark algorithms.

I. Introduction

In some Internet of things (IoT) applications, such as smart farms and opencast coal mine, the environment is normally very large. Lacking of power supply and communication infrastructures make ground terminals (GTs) difficult to transmit their monitoring data to the control center. Some GTs may rely on wireless multi-hop relay system which may dramatically increase both transmission delay and energy consumption. Recently, UAVs have been applied to support these applications due to the attractive features of high mobility and low operating cost [1]. By installing data receiving module on a UAV, it can act as a mobile base station (BS) to collect the data from GTs by single-hop communication in short range. Moreover, with the help of wireless charging modules, UAV can compensate the energy consumption of GTs by using wireless power transfer (WPT) technology [2].