Coverage Probability Analysis of IRS-Aided Communication Systems

TL;DR

This paper derives a comprehensive analytical expression for the coverage probability of IRS-aided wireless systems under Rayleigh fading, considering array element size, number, and incident angle, aiding performance evaluation and design.

Contribution

It provides the first exact closed-form and an approximate formula for coverage probability in IRS systems, accounting for array size, number, and channel conditions.

Findings

Coverage probability depends on array size, number, and incident angle.

The derived formulas enable performance evaluation of IRS systems.

The approximation is accurate for arbitrary number of elements.

Abstract

The intelligent reflective surface (IRS) technology has received many interests in recent years, thanks to its potential uses in future wireless communications, in which one of the promising use cases is to widen coverage, especially in the line-of-sight-blocked scenarios. Therefore, it is critical to analyze the corresponding coverage probability of IRS-aided communication systems. To our best knowledge, however, previous works focusing on this issue are very limited. In this paper, we analyze the coverage probability under the Rayleigh fading channel, taking the number and size of the array elements into consideration. We first derive the exact closed-form of coverage probability for the unit element. Afterward, with the method of moment matching, the approximation of the coverage probability can be formulated as the ratio of upper incomplete Gamma function and Gamma function, allowing an arbitrary number of elements. Finally, we comprehensively evaluate the impacts of essential factors on the coverage probability, such as the coefficient of fading channel, the number and size of the element, and the angle of incidence. Overall, the paper provides a succinct and general expression of coverage probability, which can be helpful in the performance evaluation and practical implementation of the IRS.