Energy-Accumulation-Based Power-Beacon-Assisted WPCN: Time Allocation and Scheduling Schemes

This letter aims to maximize the sum ergodic throughput of a power-beacon (PB)-assisted wireless powered communication network, where the PB located between several sensors and a base station (BS) first performs wireless energy transfer to the sensors and then assists forwarding the information of each sensor to the BS based on TDMA protocol. We consider the energy accumulation effect, i.e., each sensor can harvest additional energy from the PB when the PB forward the information of previous scheduled sensors, and then exhausts the accumulated energy when it starts transmission process. First, we derive the exact and approximate solutions of the ergodic throughput. Second, we prove that the optimization problem is convex and provide numerous new expressions for the optimal time allocation. Moreover, the scheduling sequence for the sensors is also optimized with two proposed methods. Simulations show the considerable gain achieved by the joint optimization scheme.