Performance analysis of multi-antenna multi-IRS assisted communication system for 6G wireless networks

A single-intelligent reflecting surface (IRS) assisted communication system is one of the potential solutions to address blockage issues by creating a virtual line-of-sight (LOS) link between the transmitter and the receiver. In this work, to address the limited coverage angle posed by single-IRS, a multi-antenna multi-IRS supported system model is considered under a generalized $\alpha -\mu$ wireless fading channel. Deriving the statistical information of the equivalent signal-to-noise ratio (SNR), the theoretical expressions of bit error rate (BER), Ergodic capacity (EC), and outage probability were derived, which cover Rayleigh, Nakagami-m, and exponential distributions as corner cases. Extensive Monte Carlo (MC) simulations demonstrate the validity of all the analytical expressions. The investigation focused on examining the impact of individual parameters such as fading parameters, the number of IRSs, the number of reflecting elements, the number of antennas at the transmitter, and the position of the IRSs. A thorough comparative analysis reveals the fact that the multiple antenna multiple IRS system outperforms in all the performance metrics under consideration, with respect to the single IRS single-input single-output (SISO) system. Furthermore, we present an energy efficiency (EE) and energy consumption gain assessment for the multi-IRS system.