Robust Resource Allocation Design for Secure IRS-Aided WPCN

This paper studies the robust resource allocation design for secure intelligent reflecting surface (IRS)-aided wireless-powered communication networks (WPCN). Specifically, deploying an IRS can establish favorable end-to-end radio propagation environment for achieving the desired performance gain in secure wireless-powered systems. We aim to minimize the total hybrid base station (HBS) transmit power by jointly designing the active transmitting and receiving beamforming at the HBS, and the passive beamforming at the IRS taking into account the secrecy rate outage requirement and the harvested power constraints of the legitimate devices. To handle the optimization problem, we propose an efficient iterative suboptimal algorithm, which attains a Karush-Kuhn-Tucker (KKT) solution of the transformed problem. Simulation results unveil that the proposed scheme can dramatically reduce the HBS transmit power over various baseline schemes. Also, our results show the superiority of IRS-aided secure communication in wireless-powered systems.