An Energy-Efficient Selection Mechanism of Relay and Edge Computing in UAV-Assisted Cellular Networks

Unmanned aerial vehicles (UAVs) enjoy the advantages of flexibility, high maneuverability and low cost, attracting remarkable interest recently in supporting cellular networks. We consider a wireless network in this paper, where the UAV serves as either an edge computing server or a relay to support the offloading of the users' tasks. By minimizing the energy consumption of users served by the UAV relay network, the transmission mode, the location and the transmission power of the UAV are optimized jointly. To solve the resulting mixed integer non-convex problem efficiently, an iterative algorithm is adopted by applying the successive convex optimization and the block coordinate descent methods. The proposed algorithm is capable to achieve the UAV's location, the users' transmission power and transmission mode selection. Simulation results show that the proposed algorithm is able to improve the energy efficiency performance of the UAV-assisted network significantly.