UAV-Aided wireless communication designs with propulsion energy limitations

In this paper, we investigate wireless communication systems where an unmanned aerial vehicle (UAV) supports data transmissions of multiple ground nodes (GNs) while maneuvering over the operating area. The propulsion energy consumption of the UAV is taken into consideration in this system, thus the UAV should operate under the certain threshold of the velocity and the acceleration. We formulate the minimum average rate maximization problem and the energy efficiency (EE) maximization problem by jointly optimizing the trajectory, velocity, and acceleration of the UAV and the uplink transmit power at the GNs. As these problems are non-convex in general, the successive convex approximation (SCA) scheme is employed. To utilize this technique, the non-convex constraints are turned into proper convex approximations, and iterative algorithms are proposed which converge to a local optimal point. From the numerical results, it is demonstrated that the proposed algorithms outperform baseline schemes for both problems. Especially for the EE maximization problem, the proposed algorithm exhibits about 109% gain over the baseline scheme.