In this paper, a multiuser wireless powered communication network is considered where all users harvest energy from power beacons by wireless power transfer to support their uplink information transmission. A frequency-division duplex transmission scheme is adopted, where downlink power transfer and uplink information transmission are separated in different frequency bands. Compared with the time-division duplex scheme considered in most of existing literature, the frequency-division duplex scheme has more freedom to optimize the charging time of different cells respectively, and more suitable for distributed deployment of power beacons. The transmission slots and power allocation problem can be formulated as an optimization problem, which is proved to be convex. We derive the optimal slots allocation algorithm with the purpose of fair sum-throughput maximization. Moreover, the asymptotic expression of throughput is obtained, which provides useful insight on the deployment of power beacons. Simulation results demonstrate the proposed scheme can achieve significant performance gains compared to existing scheme from the literature.
['Yang Li', 'Rui Wang', 'Xuewen Liao', 'Shihua Zhu']
Optimal multiuser scheduling for wireless powered communication systems