Cooperative Double-IRS Aided Communication: Beamforming Design and Power Scaling

Yitao Han, Shuowen Zhang, Lingjie Duan, Rui Zhang

Research output: Journal article publicationJournal articleAcademic researchpeer-review


Intelligent reflecting surface (IRS) is a promising technology to support high performance wireless communication. By adaptively configuring the reflection amplitude and/or phase of each passive reflecting element on it, the IRS can reshape the electromagnetic environment in favour of signal transmission. This letter advances the existing research by proposing and analyzing a double-IRS aided wireless communication system. Under the reasonable assumption that the reflection channel from IRS 1 to IRS 2 is of rank 1 (e.g., line-of-sight channel), we propose a joint passive beamforming design for the two IRSs. Based on this, we show that deploying two cooperative IRSs with in total K elements can yield a power gain of order O(K^4) , which greatly outperforms the case of deploying one traditional IRS with a power gain of order O(K^2) . Our simulation results validate that the performance of deploying two cooperative IRSs is significantly better than that of deploying one IRS given a sufficient total number of IRS elements. We also extend our line-of-sight channel model to show how different channel models affect the performance of the double-IRS aided wireless communication system.
Original languageEnglish
Article number9060923
Pages (from-to)1206-1210
Number of pages5
JournalIEEE Wireless Communications Letters
Issue number8
Publication statusPublished - Aug 2020

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