On the Exact Performance of IRS-Assisted Communications Under Random and Coherent Phase Shifts Over $\kappa-\mu$ Fading Channels

Intelligent reflective surfaces (IRS) are considered major enabling technologies for the sixth-generation (6G) of cellular networks. Since its conception, a handful of research has been conducted to characterize this new channel over different fading models. Therefore, we here investigate the effects of $\kappa-\mu$ fading in IRS-empowered systems subjected to coherent and random phase shifts. To this end, we propose new exact and mathematically tractable expressions for the signal-to-noise ratio probability density function and cumulative distribution function of the referred system. These new formulations enabled the analysis of the exact outage and coverage probability and average bit error rate. Analytical results were confronted with Monte Carlo simulations, which indicated great adherence to the proposed schemes. Finally, we investigate the system performance over coherent and random phase schemes and the impact of the carrier frequency, the number of reflecting elements, and the distance between the IRS and the user.