Trajectory Optimization for UAV-based Communication Systems Powered by Energy Harvesting

Unmanned aerial vehicles (UAV), also known as drones, is an aircraft without a human pilot onboard and controlled simultaneously by computers remotely. UAVs have been employed in different applications which include fire fighting, security, data coverage, and information transformation. UAVs represent a key technology for next-generation wireless networks that support internet of things (IoT) systems and smart cities. However, one of the bottlenecks of UAV communications systems is power consumption. Most of the UAV energy is consumed on the propulsion part which affects the ability of the UAV to transfer information. Energy harvesting can be incorporated into UAV systems to reduce network operating costs and carbon footprints. Hence, we formulate a trajectory optimization problem for UAV-based communications systems powered by energy harvesting. Then, we provide a solution based on convex optimization to tackle the UAV energy efficiency constraint. Indeed, this paper presents an energy-efficient scheme based on simultaneously powering a UAV with solar energy and optimizing the trajectory to increase the energy efficiency of the drone. This approach has not only been shown to increase the energy efficiency of the drone but also decrease the carbon footprints. Numerical simulations are done to show the efficiency of the proposed scheme.