Full-Duplex Wireless-Powered IoT Networks With Unmanned Aerial Vehicle

This paper investigates unmanned aerial vehicle (UAV)-aided full-duplex wireless powered Internet-of-things (IoT) networks, where a UAV equipped with a full-duplex hybrid access point (HAP) serves multiple sparsely distributed energy constrained IoT sensors. The UAV hovers above each sensor for one time slot for information collection. It is assumed that the transmission range of the UAV is limited, and thus, the energy broadcasted from the UAV is only available for the next adjacent sensor to harvest in the case where the sensors are sparsely distributed in the IoT networks. Since the full-duplex mode is adopted and no initial energy harvest time is allocated to the entire IoT networks, the coupling time relationship makes the solution of the model more challenging. Under the proposed model, we formulate two problems: sum-throughput maximization (STM) and total-hover-time minimization (THTM). For the STM problem, the optimal solution is obtained by applying convex optimization techniques. For the THTM problem, by exploiting the properties of the coupled constraints, we propose an algorithm to obtain an optimal solution. Finally, the numerical results show that the performance achieved by the proposed optimal time allocation scheme outperforms an equal time allocation scheme, under block-fading and line of sight (LoS) channels.