Energy Efficient Trajectory and Communication Co-Design in UAV-enabled SWIPT Systems

This paper investigates a downlink unmanned aerial vehicle (UAV)-enabled simultaneous wireless information and power transfer (SWIPT) system, in which a rotary-wing UAV is leveraged to charge distributed sensor nodes (SNs) and support information transmission simultaneously. Due to the practical hardware limitation, the dynamic power splitting (DPS) scheme is considered. We aim to maximize the UAV energy efficiency (EE) over a finite mission/communication period, by jointly optimizing the UAV trajectory, transmit power, and the power splitting ratio at the SNs. However, the optimization problem is formulated as non-linear fractional programming and thus difficult to be solved directly. To tackle this problem, we propose an iterative algorithm based on Dinkelbach method and successive convex approximation (SCA) techniques. Numerical results show that the proposed design significantly outperforms the other benchmark schemes.