UAV-assisted SWIPT for IoT networks: Priority-aware optimization of trajectory and power-splitting

Abstract

In this paper, we investigate the trajectory and service optimization problem for a priority-aware UAV-assisted simultaneous wireless information and power transfer (SWIPT) for IoT networks, where the ground nodes (GNs) have different priorities and energy and data requirements. In this system, the UAV takes off from an initial point and then visits each GN to transfer energy and transmit information as much as its requirements. The goal of the UAV is to jointly minimize the energy consumption of the UAV and the sum of the priority-weighted delays of the GNs. To solve this problem, we first transfer the multi-objective optimization problem to a single-objective optimization problem by using the weighted sum method. Then, we reformulate the problem as a variation of the traveling salesman problem (TSP) by proposing a tuple of optimal solutions for the UAV's flying strategy, service time for each GN, and proper dynamic power split adoption at each GN in a closed form. Based on this result, an optimal trajectory of the UAV is obtained by designing a dynamic programming (DP) algorithm. To reduce computational complexity, we propose some suboptimal algorithms based on the genetic algorithm (GA) with some variations of the parent selection method. Numerous numerical results are presented to show the differences in optimal flight paths according to various environmental parameters and to compare the performances of the GA-based algorithms.