Passive Beamforming for IRS Aided Wireless Networks

TL;DR

This paper proposes a low-complexity method for passive beamforming in IRS-assisted wireless networks, optimizing user signal quality in multicasting and multi-user scenarios.

Contribution

It introduces an alternating direction method of multipliers-based approach with closed-form solutions for passive beamforming optimization in IRS-assisted systems.

Findings

The proposed method effectively improves the minimum user SNR.

It demonstrates low computational complexity.

Numerical results confirm the efficiency of the approach.

Abstract

In this letter, we design passive beamforming in an intelligent reflecting surface (IRS) assisted multiple-user wireless network. Two different scenarios are considered, namely, multicasting and multi-user downlink transmission. We optimize the passive beamforming vector of the IRS to maximize the smallest signal-to-noise ratio of the users in both scenarios. Based on the alternating direction method of multipliers algorithm, a low complexity method is designed to iteratively solve the established problem. In each iteration of the proposed method, the solution is in closed form, and thus the computation complexity is low. Numerical results are presented to show the efficiency of the proposed method.