On Performance of a Ris-Aided Iot Network with Direct Link and $\alpha-\mu$ Fading

This paper explores the performance of a reconfigurable intelligent surface (RIS)-aided Internet-of-Things (IoT) network under $\alpha-\mu$ fading. The $\alpha-\mu$ fading characterizes the nonlinearity of the propagation medium and encompasses negative exponential, one-sided Gaussian, Weibull, Rayleigh, and Nakagami- $m$ fading models as special cases. We derive the cumulative distribution function of the effective channel (comprising the effect of the direct and RIS-assisted links) power gain to characterize the system performance. Specifically, we use this result to derive closed-form expressions of the outage probability (OP), symbol error rate under various digital modulation schemes, and sum throughput utilizing the Gaussian Chebyshev quadrature approximation. The asymptotic (high signal-to-noise ratio) OP is also derived, and the diversity order of the considered network is obtained. Monte-Carlo simulations are performed to verify the derived closed-form expressions. We show that deploying the RIS in close proximity to either the IoT source or the destination access point is preferred.