Ergodic performance analysis of intelligent reflecting surface network with phase errors

This paper investigates the performance of using multiple intelligent reflecting surface (IRS)-assisted communication as compared to the hybrid approach. We demonstrate that for practical scenarios with a limited amount of radiated power, the performance can be significantly enhanced by increasing numbers of IRS. Upper bounds are derived for multiple IRSs using both ideal and quantization phase errors over different channel environments. The proposed method having multiple-IRSs is validated for both Rician and Rayleigh fading scenarios, including ideal and quantization phase errors. The proposed method shows a significant improvement in terms of achievable rate by increasing number of IRS over hybrid IRS-relay scheme. A degradation in performance is observed by assuming phase quantization errors. Finally, it is demonstrated that increasing number of reflecting elements improve the achievable rate, but gets saturate with further increase in the number of reflecting elements.