Joint Trajectory Optimization and User Scheduling for Rotary-Wing UAV-Enabled Wireless Powered Communication Networks

Wireless powered communication networks are promising in the next generation wireless communication systems since they can prolong the communication time of users. However, the wireless powered performance is limited due to the low energy harvesting efficiency caused by channel fading. In order to tackle this issue, rotary-wing unmanned aerial vehicle (UAV) enabled wireless powered communication network (WPCN) is first proposed to provide energy harvesting and information transmission to multiple ground users. Then, the energy consumption minimization problem for the UAV-enabled WPCN is formulated subject to the speed, initial and final positions of the UAV, the energy harvesting causality and user scheduling constraints. Finally, an efficient algorithm by employing the path discretization and successive convex approximation techniques is proposed to solve the challenging non-convex problem. Simulation results show that our proposed scheme can efficiently balance the energy harvesting phase and transmission phase based on the optimal trajectory design, moreover, it outperforms other benchmark schemes in terms of the energy consumption.