Wireless Communications With Reconfigurable Intelligent Surface: Path Loss Modeling and Experimental Measurement

By Wankai Tang, Ming Zheng Chen, Jun Yan Dai, Yu Han, M. Di Renzo, Yong Zeng, Shi Jin, Qiang Cheng, T. Cui. IEEE Transactions on Wireless Communications, 2019

1,494 citations recorded by the source corpus.

Reconfigurable intelligent surfaces (RISs) comprised of tunable unit cells have recently drawn significant attention due to their superior capability in manipulating electromagnetic waves. In particular, RIS-assisted wireless communications have the great potential to achieve significant performance improvement and coverage enhancement in a cost-effective and energy-efficient manner, by properly programming the reflection coefficients of the unit cells of RISs. In this article, free-space path loss models for RIS-assisted wireless communications are developed for different scenarios by studying the physics and electromagnetic nature of RISs. The proposed models, which are first validated through extensive simulation results, reveal the relationships between the free-space path loss of RIS-assisted wireless communications and the distances from the transmitter/receiver to the RIS, the size of the RIS, the near-field/far-field effects of the RIS, and the radiation patterns of antennas and unit cells. In addition, three fabricated RISs (metasurfaces) are utilized to further corroborate the theoretical findings through experimental measurements conducted in a microwave anechoic chamber. The measurement results match well with the modeling results, thus validating the proposed free-space path loss models for RISs, which may pave the way for further theoretical studies and practical applications in this field.

Subfields: Aerospace Engineering, Electrical and Electronic Engineering

View Paper: https://www.semanticscholar.org/paper/865983382d1394a7b49246a70cda947e97f18d84

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Citations in the corpus

Smart Radio Environments Empowered by Reconfigurable Intelligent Surfaces: How it Works, State of Research, and Road Ahead (2020, background): “In [13], the authors perform a measurement campaign in an anechoic chamber and show that the power reflected from an RIS follows a scaling law that depends on many parameters, including the size of the RIS, the mutual distances between the transmitter/receiver and the RIS (i.”
Reconfigurable Intelligent Surfaces for Wireless Communications: Principles, Challenges, and Opportunities (2020, background): “This has been analyzed theoretically in [26], [27], [29] and observed in empirical measurements conducted in [27].”
Stacked Intelligent Metasurfaces for Efficient Holographic MIMO Communications in 6G (2023, neutral): “severely impacts the resultant performance [43].”
Intelligent Reflecting Surface-Aided Wireless Communications: A Tutorial (2020, background): “Interested readers may refer to [46], [51], [58] for more details on IRS energy consumption modelling as well as the impact of energy consumption on its performance comparison with conventional active relays.”
Channel Estimation for RIS-Empowered Multi-User MISO Wireless Communications (2020, background): “candidate technology for beyond 5-th Generation (5G) wireless communication, mainly due to their significant potential for enabling low-power, energy-efficient, high-speed, massiveconnectivity, and low-latency wireless communications [2]– [10].”
Toward Smart Wireless Communications via Intelligent Reflecting Surfaces: A Contemporary Survey (2019, background): “Based on a detailed study on the IRS’s physics and EM nature, the authors in [86] propose a more reliable free-space path loss model for IRS-assisted wireless communications.”
Smart Radio Environments Empowered by Reconfigurable Intelligent Surfaces: How It Works, State of Research, and The Road Ahead (2020, background): “2 is made of 3,720 inexpensive individually tunable antennas and the RIS prototype in [13] is made of 10,000 unit cells.”
MIMO Transmission Through Reconfigurable Intelligent Surface: System Design, Analysis, and Implementation (2019, background): “Let dx, dy , G, and F (θ, φ) denote the width, length, gain, and the normalized power radiation pattern of Un,m, respectively [35], [36].”
Near-Field Communications: A Tutorial Review (2023, methodology): “• Validation of existing models by channel measurements: Further validation of statistical channel models for NFC is required using empirical measurements [44].”
Beam Focusing for Near-Field Multi-User MIMO Communications (2021, background): “In addition, [15], [16] considered near-field communication in reconfigurable intelligent surfaces (RISs)-assisted systems, where RISs act as a passive reflector.”
Physics-Based Modeling and Scalable Optimization of Large Intelligent Reflecting Surfaces (2020, background): “Proof-of-concept implementations conﬁrming the beneﬁts of IRSs have been reported in [8]–[10].”
An Overview of Signal Processing Techniques for RIS/IRS-Aided Wireless Systems (2021, neutral): “Based on [21] and [230], the path loss of the BS-MU channel in (112a) can be expressed in dB as where d BM is the distance (in meters) between the BS and the MU, α 0 is the path loss exponent. ξ 0 ∼ N (0 , σ 2 SF 0 ) is the log-normal term accounting for the shadow fading, where σ 2 SF 0 denotes…”
Communicating With Extremely Large-Scale Array/Surface: Unified Modeling and Performance Analysis (2021, neutral): “…have attracted fast-growing interest recently, such as extremely large-scale multiple-input multiple-output (XL-MIMO) communication [6], [7], Terahertz communication [8], [9], intelligent reﬂecting surface (IRS) or reconﬁgurable intelligent surface (RIS)-assisted communications [10]–[14].”
Reconfigurable Intelligent Surfaces: Principles and Opportunities (2020, methodology): “As the field point approaches the boundary, the power density reaches its asymptotic limit determined by the z−2 factor, as reported in [42] and [43].”
Holographic MIMO Surfaces for 6G Wireless Networks: Opportunities, Challenges, and Trends (2019, methodology): “IEEE Wireless Communications • October 2020 123 massive MIMO systems, HMIMOS operation can be described by the Fresnel-Kirchhoff integral that is based on the Huygens-Fresnel principle [9].”
RIS-Aided Wireless Communications: Prototyping, Adaptive Beamforming, and Indoor/Outdoor Field Trials (2021, result): “This observation is in line with the results in [37], where the phase variations due to different incident angles were even bigger.”
A Vision and Framework for the High Altitude Platform Station (HAPS) Networks of the Future (2020, background): “A recent experiment demonstrated that the conﬁguration of each reﬂector unit consumed 0.33 mW [114].”
Path Loss Modeling and Measurements for Reconfigurable Intelligent Surfaces in the Millimeter-Wave Frequency Band (2021, methodology): “BRIEF REVIEW OF PATH LOSS MODELS FOR RISS In this section, we give a brief summary of the free-space path loss models for RISs proposed in [22], and discuss their limitations and how they can be improved.”