Reconfigurable Intelligent Surfaces vs. Relaying: Differences, Similarities, and Performance Comparison

@article{DiRenzo2020ReconfigurableIS,
  title={Reconfigurable Intelligent Surfaces vs. Relaying: Differences, Similarities, and Performance Comparison},
  author={Marco Di Renzo and Konstantinos Ntontin and Jian Song and Fadil Habibi Danufane and Xuewen Qian and Fotis I. Lazarakis and Julien de Rosny and Dinh-Thuy Phan-Huy and Osvaldo Simeone and Rui Zhang and Meroaune Debbah and Geoffroy Lerosey and Mathias Fink and Sergei A. Tretyakov and Shlomo Shamai},
  journal={IEEE Open Journal of the Communications Society},
  year={2020},
  volume={1},
  pages={798-807}
}
Reconfigurable intelligent surfaces (RISs) have the potential of realizing the emerging concept of smart radio environments by leveraging the unique properties of meta-surfaces. [] Key Result Finally, we discuss the key open issues that need to be addressed in order to unlock the potential of RISs, and, in particular, to unveil their ultimate performance limits and to optimize their deployment in future wireless networks.

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Smart Radio Environments Empowered by Reconfigurable Intelligent Surfaces: How It Works, State of Research, and The Road Ahead
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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.
Wireless Communications With Reconfigurable Intelligent Surface: Path Loss Modeling and Experimental Measurement
TLDR
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.
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