Active RIS aided SWIPT secure communication system with partial CSI

Abstract

The effectiveness of passive reconfigurable intelligent surface (RIS)-assisted simultaneous wireless information and power transfer (SWIPT) may be limited by significant path loss. Active RIS addresses the “multiplicative fading” observed in traditional passive RIS systems. However, the absence of a radio frequency chain in the RIS poses challenges in acquiring necessary channel state information (CSI) at the base station (BS). We investigates an active RIS-assisted SWIPT system with partial CSI. By optimizing transmit and reflection beamforming concurrently, the RIS and BS minimize power consumption while meeting requirements for information and energy receivers, along with a rate outage constraint for the Eve. Simulation results show that active RIS approach offers a promising solution to mitigate power loss and improve overall SWIPT system performance.