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