Energy Consumption Minimization of Rotary-Wing UAVs for Data Distribution

In this letter, we investigate a rotary-wing unmanned aerial vehicle (UAV)-supported data distribution system. Specifically, a UAV transmits data to a group of ground users, aiming to minimize the UAV energy consumption via trajectory optimization. To cope with the non-convex optimization problem that involves continuous time variables, we first consider a benchmark "hovering-to-communicate" scheme where the UAV sequentially visits a series of hovering positions to transmit data. In this case, the formulated problem can be transformed into the traveling salesman problem and solved. Next, we consider a generalized "flying-to-communicate" scheme where the UAV sends data to ground users while flying. In this case, the formulated problem can be reduced to a tractable form with a finite number of variables via trajectory discretization, whose approximately optimal solution is derived by successive convex approximation technique. Simulation results demonstrate that the proposed algorithm can effectively reduce the UAV energy consumption.