Energy Minimization for Wireless Communication With Rotary-Wing UAV

TLDR

This paper studies UAV‑enabled wireless communication with a rotary‑wing UAV serving multiple ground nodes, a problem that is non‑convex and involves infinitely many time‑varying variables. The study aims to minimize the UAV’s total energy consumption, including propulsion and communication energy, while meeting each ground node’s throughput requirement. The authors derive a closed‑form propulsion power model and formulate a joint trajectory and time‑allocation optimization; they solve it first with a fly‑hover‑communicate design using a TSP‑with‑neighborhood algorithm and convex optimization, then extend to a general flying‑communication case via path discretization and successive convex approximation to obtain a high‑quality suboptimal solution. Numerical results demonstrate that the proposed designs significantly outperform benchmark schemes.

Abstract

This paper studies unmanned aerial vehicle (UAV)-enabled wireless communication, where a rotary-wing UAV is dispatched to communicate with multiple ground nodes (GNs). We aim to minimize the total UAV energy consumption, including both propulsion energy and communication related energy, while satisfying the communication throughput requirement of each GN. To this end, we first derive a closed-form propulsion power consumption model for rotary-wing UAVs, and then formulate the energy minimization problem by jointly optimizing the UAV trajectory and communication time allocation among GNs, as well as the total mission completion time. The problem is difficult to be optimally solved, as it is non-convex and involves infinitely many variables over time. To tackle this problem, we first consider the simple fly-hover-communicate design, where the UAV successively visits a set of hovering locations and communicates with one corresponding GN while hovering at each location. For this design, we propose an efficient algorithm to optimize the hovering locations and durations, as well as the flying trajectory connecting these hovering locations, by leveraging the travelling salesman problem with neighborhood and convex optimization techniques. Next, we consider the general case, where the UAV also communicates while flying. We propose a new path discretization method to transform the original problem into a discretized equivalent with a finite number of optimization variables, for which we obtain a high-quality suboptimal solution by applying the successive convex approximation technique. The numerical results show that the proposed designs significantly outperform the benchmark schemes.