Authors : Asmaa Nasr Alfeetouri; Amer R. Zerek; Olga Boiprav

Volume/Issue : Volume 11 - 2026, Issue 7 - July

Google Scholar : https://tinyurl.com/28bu8rja

Scribd : https://tinyurl.com/ms2y7yrs

DOI : https://doi.org/10.38124/ijisrt/26jul228

Note : A published paper may take 4-5 working days from the publication date to appear in PlumX Metrics, Semantic Scholar, and ResearchGate.

Abstract : This paper investigates signal-to-noise ratio (SNR) and channel capacity performance in Reconfigurable Intelligent Surface (RIS)-assisted wireless systems under Rayleigh and Rician fading channels as a function of distance. A cascaded channel model was adopted for the RIS-reflected link, where N passive elements applied optimal phase alignment to maximize received SNR. Distinct path-loss exponents were used: 3.5 for Rayleigh (NLOS) and 2.2 for Rician (LOS) channels, with a Rician K-factor of 10 dB. Monte Carlo simulations with 5,000 trials were conducted for N = 16, 32, 64, and 128 RIS elements over distances from 5 m to 200 m. At the reference distance d = 100 m, Rician fading yielded an SNR gain of approximately 45.8 dB and a capacity gain of approximately 15.2 bps/Hz over Rayleigh fading, independent of N. The quadratic (N-squared) power scaling law was confirmed, with each doubling of N yielding approximately 6 dB additional SNR.

Keywords : Reconfigurable Intelligent Surface (RIS), SNR Modeling, Rayleigh Fading, Rician Fading, Path-Loss Exponent, Cascaded Channel, Monte Carlo Simulation, Channel Capacity.

References :

1. P. Putranto et al., "Reconfigurable Intelligent Surfaces for 6G and Beyond: A Comprehensive Survey from Theory to Deployment," arXiv:2506.19625, 2025.
2. E. Basar et al., "Wireless Communications Through Reconfigurable Intelligent Surfaces," IEEE Access, vol. 7, pp. 116753–116773, 2019.
3. E. Björnson and L. Sanguinetti, "Rayleigh Fading Modeling and Channel Hardening for Reconfigurable Intelligent Surfaces," IEEE Wireless Commun. Lett., vol. 10, no. 4, pp. 830–834, 2021.
4. Q. Wu and R. Zhang, "Towards Smart and Reconfigurable Environment: Intelligent Reflecting Surface Aided Wireless Network," IEEE Commun. Mag., vol. 58, no. 1, pp. 106–112, 2020.
5. K. K. Kota, P. D. Mankar, and H. S. Dhillon, "Characterization of Capacity and Outage of RIS-aided Downlink Systems under Rician Fading," arXiv:2404.08039, 2024.
6. C. Singh and C. H. Lin, "Reconfigurable Intelligent Surfaces Aided Communication: Capacity and Performance Analysis Over Rician Fading Channel," arXiv:2107.10937, 2021.
7. X. Qian, M. Di Renzo, J. Liu, A. Kammoun, and M.-S. Alouini, "Beamforming Through Reconfigurable Intelligent Surfaces in Single-User MIMO Systems: SNR Distribution and Scaling Laws in the Presence of Channel Fading and Phase Noise," IEEE Wireless Communications Letters, 2020. arXiv:2005.07472.
8. K. K. Kota, P. D. Mankar, and H. S. Dhillon, "Optimal Beamforming and Outage Analysis for Max Mean SNR under RIS-aided Communication," arXiv:2211.09337, 2022.
9. D. Selimis et al., "On the Performance Analysis of RIS-Empowered Communications Over Nakagami-m Fading," IEEE Commun. Lett., 2023.
10. I. Trigui, W. Ajib, and W.-P. Zhu, "A Comprehensive Study of Reconfigurable Intelligent Surfaces in Generalized Fading," IEEE Transactions on Communications, vol. 69, no. 10, pp. 6734-6749, Oct. 2021. arXiv:2004.02922.
11. Y. Yuan, Y. Huang, X. Su, B. Duan, N. Hu, and M. Di Renzo, "Reconfigurable Intelligent Surface (RIS) System Level Simulations for Industry Standards," IEEE Communications Magazine, accepted, 2024. arXiv:2409.13405.
12. I. Trigui et al., "Bit Error Rate Analysis for Reconfigurable Intelligent Surfaces with Phase Errors," arXiv:2101.03261, 2021.
13. I. Singh, P. J. Smith, and P. A. Dmochowski, "Optimal SNR Analysis for Single-user RIS Systems in Ricean and Rayleigh Environments," arXiv:2110.03801, 2021.
14. A. M. Elbir and K. V. Mishra, "A Survey of Deep Learning Architectures for Intelligent Reflecting Surfaces," IEEE Commun. Surveys Tuts., 2022.
15. J. Zhang et al., "Cascaded Channel Modeling and Experimental Validation for RIS Assisted Communication System," 2024.