Performance Characterization of an IRS-assisted OFDM System with HPA Memory Effects and IRS Phase Noise

In the realm of forthcoming wireless communication systems, various technologies have emerged, with intelligent reflective surfaces (IRSs) standing out as a promising contender for enhancing spectral and energy efficiency. The effectiveness of such systems is significantly impaired by the nonlinear characteristics inherent in their components. This work examines the collective impact of nonlinearity stemming from memory effects in high power amplifiers (HPAs) and phase noise from the IRS on an orthogonal frequency division multiplexing (OFDM) system. Specifically, the performance is evaluated by deriving mathematical expressions for determining the outage probability (OP), spectral efficiency (SE), and energy efficiency (EE) in an OFDM communication system augmented by an IRS, while considering the effects of non-ideal HPA and phase noise in the IRS. We validate our analytical results through comparison with simulations, confirming the accuracy of our approach. Our findings highlight the significant impact of HPA nonlinearity and IRS phase noise on the performance of the above communication system.