Intelligent Reflecting Surface-Assisted Cognitive Radio System
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Numerical results demonstrate that IRS can significantly improve the achievable rate of SU under both perfect and imperfect CSI cases, and jointly optimizing the beamforming at SU-TX and the reflecting coefficients at each IRS.Abstract:
Cognitive radio (CR) is an effective solution to improve the spectral efficiency (SE) of wireless communications by allowing the secondary users (SUs) to share spectrum with primary users (PUs). Meanwhile, intelligent reflecting surface (IRS), also known as reconfigurable intelligent surface (RIS), has been recently proposed as a promising approach to enhance energy efficiency (EE) of wireless communication systems through intelligently reconfiguring the channel environment. To improve both SE and EE, in this paper, we introduce multiple IRSs to a downlink multiple-input single-output (MISO) CR system, in which a single SU coexists with a primary network with multiple PU receivers (PU-RXs). Our design objective is to maximize the achievable rate of SU subject to a total transmit power constraint on the SU transmitter (SU-TX) and interference temperature constraints on the PU-RXs, by jointly optimizing the beamforming at SU-TX and the reflecting coefficients at each IRS. Both perfect and imperfect channel state information (CSI) cases are considered in the optimization. Numerical results demonstrate that IRS can significantly improve the achievable rate of SU under both perfect and imperfect CSI cases.read more
Citations
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Journal ArticleDOI
Intelligent Reflecting Surface-Aided Wireless Communications: A Tutorial
TL;DR: This paper provides a tutorial overview of IRS-aided wireless communications, and elaborate its reflection and channel models, hardware architecture and practical constraints, as well as various appealing applications in wireless networks.
Journal ArticleDOI
Smart Radio Environments Empowered by Reconfigurable Intelligent Surfaces: How It Works, State of Research, and The Road Ahead
Marco Di Renzo,Alessio Zappone,Merouane Debbah,Mohamed-Slim Alouini,Chau Yuen,Julien de Rosny,Sergei A. Tretyakov +6 more
TL;DR: Reconfigurable intelligent surfaces (RISs) can be realized in different ways, which include (i) large arrays of inexpensive antennas that are usually spaced half of the wavelength apart; and (ii) metamaterial-based planar or conformal large surfaces whose scattering elements have sizes and inter-distances much smaller than the wavelength.
Posted Content
Smart Radio Environments Empowered by Reconfigurable Intelligent Surfaces: How it Works, State of Research, and Road Ahead.
Marco Di Renzo,Alessio Zappone,Merouane Debbah,Mohamed-Slim Alouini,Chau Yuen,Julien de Rosny,Sergei A. Tretyakov +6 more
TL;DR: The emerging research field of RIS-empowered SREs is introduced; the most suitable applications of RISs in wireless networks are overviewed; an electromagnetic-based communication-theoretic framework for analyzing and optimizing metamaterial-based RISs is presented; and the most important research issues to tackle are discussed.
Journal ArticleDOI
Reconfigurable Intelligent Surfaces: Principles and Opportunities
TL;DR: A comprehensive overview of the state-of-the-art on RISs, with focus on their operating principles, performance evaluation, beamforming design and resource management, applications of machine learning to RIS-enhanced wireless networks, as well as the integration of RISs with other emerging technologies.
Posted Content
Reconfigurable Intelligent Surfaces: Principles and Opportunities
Yuanwei Liu,Xiao Liu,Xidong Mu,Tianwei Hou,Jiaqi Xu,Zhijin Qin,Marco Di Renzo,Naofal Al-Dhahir +7 more
TL;DR: A comprehensive overview of the state-of-the-art on RISs, with focus on their operating principles, performance evaluation, beamforming design and resource management, applications of machine learning to RIS-enhanced wireless networks, as well as the integration of RISs with other emerging technologies is provided in this article.
References
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