Outage Probability Analysis of IRS-Assisted Systems Under Spatially Correlated Channels

TL;DR

This paper derives closed-form expressions for outage probability in IRS-assisted SISO systems considering spatially correlated channels, revealing how correlation impacts system reliability especially when the direct channel is blocked.

Contribution

It provides novel closed-form formulas for outage probability under arbitrary phase shifts and correlation matrices, enhancing understanding of spatial correlation effects in IRS systems.

Findings

Closed-form outage probability expressions derived.

Spatial correlation significantly reduces outage probability.

Results validated through numerical simulations.

Abstract

This paper investigates the impact of spatial channel correlation on the outage probability of intelligent reflecting surface (IRS)-assisted single-input single-output (SISO) communication systems. In particular, we derive a novel closed-form expression of the outage probability for arbitrary phase shifts and correlation matrices of the indirect channels. To shed light on the impact of the spatial correlation, we further attain the closed-form expressions for two common scenarios met in the literature when the large-scale fading coefficients are expressed by the loss over a propagation distance. Numerical results validate the tightness and effectiveness of the closed-form expressions. Furthermore, the spatial correlation offers significant decreases in the outage probability as the direct channel is blocked.