Simultaneous Uplink and Downlink Transmissions for Wireless Powered Communication Networks

In this letter, we propose a novel simultaneous uplink (UL) and downlink (DL) transmission scheme aiming to achieve a higher spectral efficiency for wireless power communication networks (WPCNs). Specifically, by exploiting full-duplex (FD) radio and wireless power transfer techniques, an FD hybrid access point is able to communicate with a wireless powered UL user and a DL user over the same time-frequency resource. The optimization problem of interest is to maximize the sum rate of the scheme under a given power budget, which is formulated as a nonconvex problem. To this end, we propose a low-complexity path following algorithm for its solution. Numerical results reveal that the proposed scheme indeed achieves substantial sum-rate improvement for the WPCNs.