IRS-Assisted Coordinated Direct and Multiantenna Relay Transmission for MIMO SWIPT Systems

To harness the benefits of intelligent reflecting surfaces, relaying technologies, multiple-input--multiple-output (MIMO), and energy harvesting, this work investigates the performance of IRS-assisted coordinated direct and multiantenna relay transmission for MIMO simultaneous wireless information and power transfer (SWIPT) systems. We consider a hybrid time-switching and power-splitting protocol for SWIPT to facilitate a comprehensive framework and flexible network design configuration. Under the Rayleigh fading channels, the outage probability (OP), effective throughput, energy efficiency, and tight upper bound of the ergodic capacity of the proposed system are derived in closed-form expressions. Furthermore, to provide qualitative conclusions on system performance, the asymptotic OP is analyzed in the high signal-to-noise regime. A set of rigorous numerical results is provided to validate the correctness of our analysis and present system-specific insights. In addition, the approximate diversity order of the proposed system is indicated.