Stable Matching for Selection of Intelligent Reflecting Surfaces in Multiuser MISO Systems

TL;DR

This paper introduces a stable matching-based IRS selection strategy for multiuser MISO systems, improving sum rate performance by ensuring stable user-IRS pairings through a two-stage algorithm.

Contribution

It proposes a novel IRS selection method using stable matching theory, specifically addressing interference issues in multiuser systems.

Findings

Achieves higher sum rate compared to distance-based matching.

Ensures stable user-IRS pairings in multiuser MISO systems.

Validates effectiveness through numerical simulations.

Abstract

In this letter, we present an intelligent reflecting surface (IRS) selection strategy for multiple IRSs aided multiuser multiple-input single-output (MISO) systems. In particular, we pose the IRS selection problem as a stable matching problem. A two stage user-IRS assignment algorithm is proposed, where the main objective is to carry out a stable user-IRS matching, such that the sum rate of the system is improved. The first stage of the proposed algorithm employs a well-known Gale Shapley matching designed for the stable marriage problem. However, due to interference in multiuser systems, the matching obtained after the first stage may not be stable. To overcome this issue, one-sided (i.e., only IRSs) blocking pairs (BPs) are identified in the second stage of the proposed algorithm, where the BP is a pair of IRSs which are better off after exchanging their partners. Thus, the second stage validates the stable matching in the proposed algorithm. Numerical results show that the proposed assignment achieves better sum rate performance compared to distance-based and random matching algorithms.