Reconfigurable Intelligent Surfaces for Wireless Communications: Principles, Challenges, and Opportunities

By Mohamed A. Elmossallamy, Hongliang Zhang, Lingyang Song, Karim G. Seddik, Zhu Han, Geoffrey Y. Li. IEEE Transactions on Cognitive Communications and Networking, 2020

638 citations recorded by the source corpus.

Recently there has been a flurry of research on the use of reconfigurable intelligent surfaces (RIS) in wireless networks to create smart radio environments. In a smart radio environment, surfaces are capable of manipulating the propagation of incident electromagnetic waves in a programmable manner to actively alter the channel realization, which turns the wireless channel into a controllable system block that can be optimized to improve overall system performance. In this article, we provide a tutorial overview of reconfigurable intelligent surfaces (RIS) for wireless communications. We describe the working principles of reconfigurable intelligent surfaces (RIS) and elaborate on different candidate implementations using metasurfaces and reflectarrays. We discuss the channel models suitable for both implementations and examine the feasibility of obtaining accurate channel estimates. Furthermore, we discuss the aspects that differentiate RIS optimization from precoding for traditional MIMO arrays highlighting both the arising challenges and the potential opportunities associated with this emerging technology. Finally, we present numerical results to illustrate the power of an RIS in shaping the key properties of a MIMO channel.

Subfields: Aerospace Engineering, Electrical and Electronic Engineering

View Paper: https://www.semanticscholar.org/paper/d3272d33f5f0d49f1cd59f4b209ce3e055fc87a8

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Citations in the corpus

A Survey on Channel Estimation and Practical Passive Beamforming Design for Intelligent Reflecting Surface Aided Wireless Communications (2021, methodology): “[27] 2020/Tutorial Hardware implementations & channel modeling Introduce different hardware implementations of RIS using metasurface and reflectarray, and discuss channel modeling as well as challenges and opportunities in RIS-aided wireless networks.”
Active Reconfigurable Intelligent Surface-Aided Wireless Communications (2021, background): “RECONFIGURABLE intelligent surface (RIS), driven by the reflective radio, has recently attracted great attentions from both academia and industry, due to its potential to intelligently reconfigure wireless communication environment with cost-effective reflecting elements (REs) [1]–[3].”
5G-Advanced Toward 6G: Past, Present, and Future (2023, background): “Broadly speaking, RIS is an umbrella term for twodimensional arrays, usually based on metamaterial or classical antennas with fast electronic switching, that can manipulate electromagnetic waves via anomalous reflection, refraction, polarization transformation, among other functionalities [110],”
Reconfigurable Intelligent Surface (RIS) Assisted Wireless Coverage Extension: RIS Orientation and Location Optimization (2020, background): “RECONFIGURABLE intelligent surfaces (RIS) are an emerging wireless communication technology and is capable of shaping the propagation environment into a desired form [1], [2].”
Intelligent Reflecting Surface-Aided Wireless Communications: A Tutorial (2020, methodology): “[33] Overview different implementations of RIS using metasurface and reflectarray, and discuss suitable RIS channel modelling as well as challenges and opportunities in RIS-aided wireless networks.”
The Road Towards 6G: A Comprehensive Survey (2021, background): “The so-called IRS, a.k.a. reconﬁgurable intelligent surfaces (RIS) [124], is assembled by a category of programmable and reconﬁgurable material sheets that are capable of adaptively modifying their radio reﬂecting characteristics.”