Optimizing the Age of Information in RIS-aided SWIPT Networks

TL;DR

This paper investigates optimizing the freshness of data (AoI) in RIS-assisted SWIPT networks by proposing a joint beamforming and phase shift optimization scheme to minimize AoI while satisfying energy transfer requirements.

Contribution

It introduces a novel joint optimization framework for AoI and energy transfer in RIS-aided SWIPT networks, employing AO and SCA algorithms for efficient solution.

Findings

Proposed algorithm reduces AoI effectively.

Trade-off between AoI and energy harvesting demonstrated.

Numerical results validate the optimization approach.

Abstract

In this letter, a reconfigurable intelligent surface (RIS)-assisted simultaneous wireless information and power transfer (SWIPT) network is investigated. To quantify the freshness of the data packets at the information receiver, the age of information (AoI) is considered. To minimize the sum AoI of the information users while ensuring that the power transferred to energy harvesting users is greater than the demanded value, we formulate a scheduling scheme, and a joint transmit beamforming and phase shift optimization at the base station (BS) and RIS, respectively. The alternating optimization (AO) algorithm is proposed to handle the coupling between active beamforming and passive RIS phase shifts, and the successive convex approximation (SCA) algorithm is utilized to tackle the non-convexity of the formulated problems. The improvement in terms of AoI provided by the proposed algorithm and the trade-off between the age of information and energy harvesting is quantified by the numerical simulation results.