IRS-Aided SWIPT: Joint Waveform, Active and Passive Beamforming Design Under Nonlinear Harvester Model

The performance of Simultaneous Wireless Information and Power Transfer (SWIPT) is mainly constrained by the received Radio-Frequency (RF) signal strength. To tackle this problem, we introduce an Intelligent Reflecting Surface (IRS) to compensate propagation loss boost transmission efficiency. This paper proposes a novel IRS-aided SWIPT system where multi-carrier multi-antenna Access Point (AP) transmits information power simultaneously, with assist IRS, single-antenna User Equipment (UE) employing practical receiving schemes. Considering harvester nonlinearity, characterize achievable Rate-Energy (R-E) region through joint optimization waveform, active passive beamforming based on Channel State at Transmitter (CSIT). problem solved Block Coordinate Descent (BCD) method, obtain precoder in closed form, Successive Convex Approximation (SCA) approach, waveform amplitude Geometric Programming (GP) technique. facilitate implementation, also propose low-complexity design closed-form adaptive Simulation results demonstrate proposed algorithms bring considerable R-E gains robustness CSIT inaccuracy finite IRS states, emphasize importance modeling nonlinearity design.