Abstract:
In this paper, we study an unmanned aerial vehicle
(UAV) assisted communication system to provide service to the
ground users. We address the problem of UAV deployment in
three-dimensional (3D) space to provide on-demand coverage to
the users such that their sum rate is maximized. First, we find
the optimal UAV location in 3D space where the sum rate is
maximized for all ground users. Thereafter an optimal trajectory
is designed for the UAV to travel from the initial to the optimal
location, such that the overall average sum rate during the flight
is maximized while meeting the on-board energy availability
and flight duration constraints. The problem formulated is nonconvex. To obtain the optimal location, we approximate the rate
expression to obtain the concave regions and apply alternating
optimization. An iterative scheme is proposed to obtain the
optimal UAV trajectory, which computes the optimal location
in each time slot sequentially, followed by a greedy approach to
reach the final location. Simulation results provide useful insights
into the optimal location and the UAV trajectory problem and
show on an average 16.5% improvement over the benchmark
schemes.
