Double-IRS Assisted Multi-User MIMO: Cooperative Passive Beamforming Design

By Beixiong Zheng, Changsheng You, Rui Zhang. IEEE Transactions on Wireless Communications, 2020

328 citations recorded by the source corpus.

Intelligent reflecting surface (IRS) has emerged as an enabling technology to achieve smart and reconfigurable wireless communication environment cost-effectively. Prior works on IRS mainly consider its passive beamforming design and performance optimization without the inter-IRS signal reflection, which thus do not unveil the full potential of multi-IRS assisted wireless networks. In this paper, we study a double-IRS assisted multi-user communication system with the cooperative passive beamforming design that captures the multiplicative beamforming gain from the inter-IRS channel. Under the general channel setup with the co-existence of both double- and single-reflection links, we jointly optimize the (active) receive beamforming at the base station (BS) and the cooperative (passive) reflect beamforming at the two distributed IRSs (deployed near the BS and users, respectively) to maximize the minimum signal-to-interference-plus-noise ratio (SINR) of all users. Moreover, for the single-user and multi-user setups, we analytically show the superior performance of the double-IRS cooperative system over the conventional single-IRS system in terms of the maximum signal-to-noise ratio (SNR) and multi-user effective channel rank, respectively. Simulation results validate our analytical results and show the practical advantages of the proposed double-IRS system with cooperative passive beamforming designs.

Subfields: Electrical and Electronic Engineering, Ocean Engineering

View Paper: https://www.semanticscholar.org/paper/4c1006ee7d14cb16e10828f5d2ceef4565143cd2

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Citations in the corpus

Simultaneously Transmitting And Reflecting (STAR) RIS Aided Wireless Communications (2021, methodology): “To overcome signal blockages, the authors of [18] proposed to use two RISs to connect a BS to users in a signal dead zone, where cooperative passive beamforming among RISs was proposed.”
Intelligent Reflecting Surface-Aided Wireless Communications: A Tutorial (2020, methodology): “The work of [143] was later extended to more practical and general scenarios of Rician fading channel and multiantenna/user systems in [131] and [144], respectively.”
A Survey on Channel Estimation and Practical Passive Beamforming Design for Intelligent Reflecting Surface Aided Wireless Communications (2021, background): “For example, let us consider the double-IRS aided communication system where a new IRS (labeled as IRS 2) is deployed near the BS in addition to the conventional single IRS (labeled as IRS 1) deployed near the users [97].”