A Maximum Throughput Design for Wireless Powered Communication Networks With IRS-NOMA

In this letter, we consider wireless powered communication networks (WPCNs) that consist of a hybrid access-point (H-AP) with a single antenna, an intelligent reflecting surface (IRS), and multiple users, each with a single antenna. In the downlink, users harvest energy from both an energy signal transmitted from the H-AP, and the reflected signal at the IRS. In the uplink, users transmit information using harvested energy, following non-orthogonal multiple access (NOMA). In particular, the signals from users and the reflected signals at the IRS are superposed and received at the H-AP. The sum-throughput for the considered network is maximized by jointly optimizing the transmit time, power, and phase shifts induced by the IRS. Numerical results show the sum-throughput enhancement by the IRS, and the impact of the IRS on the user fairness of the system.