Rayleigh Fading Modeling and Channel Hardening for Reconfigurable Intelligent Surfaces

• Published in: IEEE wireless communications letters Vol. 10; no. 4; pp. 830 - 834
• Main Authors: Bjornson, Emil, Sanguinetti, Luca
• Format: Journal Article
• Language: English
• Published: Piscataway IEEE 01.04.2021; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Antennas; channel hardening; channel modeling; Correlation; Correlation analysis; Eigenvalues and eigenfunctions; Fading; Fading channels; Geometry; Hardening; Interlocking signals; isotropic scattering; Multiple-antenna technology; Performance assessment; Rayleigh channels; Rayleigh fading; Rayleigh fading channel modeling; Rayleigh fading model; Receivers; Reconfigurable intelligent surface; Reconfigurable intelligent surfaces; Rectangular geometry; Scattering; Scattering environment; spatial correlation; Theoretical research; Transmitters; Wireless technologies; Geometry; Correlation; Transmitters; Reconfigurable intelligent surface; channel modeling; Scattering; Rayleigh channels; Receivers; Eigenvalues and eigenfunctions; spatial correlation; channel hardening; isotropic scattering
• ISSN: 2162-2337; 2162-2345; 2162-2345
• DOI: 10.1109/LWC.2020.3046107

A realistic performance assessment of any wireless technology requires the use of a channel model that reflects its main characteristics. The independent and identically distributed Rayleigh fading channel model has been (and still is) the basis of most theoretical research on multiple antenna technologies in scattering environments. This letter shows that such a model is not physically appearing when using a reconfigurable intelligent surface (RIS) with rectangular geometry and provides an alternative physically feasible Rayleigh fading model that can be used as a baseline when evaluating RIS-aided communications. The model is used to revisit the basic RIS properties, e.g., the rank of spatial correlation matrices and channel hardening.