Performances analysis of UAV-assisted wireless powered sensor network

Utilising radio frequency signals for wireless energy transmission is regarded as an effective method for energy-constrained sensor nodes to charge. Furthermore, unmanned aerial vehicle (UAV) has attracted increased attention because of their high flexibility and low-cost. We propose a novel UAV-assisted wireless rechargeable sensor network, where the energy-constrained sensors firstly harvest energy from the radio frequency signals of UAV and then forward the information to the sink node with harvesting energy. The closed-form expressions of system throughput and outage probability in AF and DF modes are both derived. Additionally, the theoretical derivation model is validated with simulation results. In particular, the results show that the DF protocol is superior to the AF protocol with lower probability and higher throughput. Besides, the influences of energy harvest time, the transmission power of UAV, and target signal-to-noise ratio on the throughput and outage probability are systematically analysed.