IEEE Open Journal of the Communications Society (Jan 2020)

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

  • Marco Di Renzo,
  • Konstantinos Ntontin,
  • Jian Song,
  • Fadil H. Danufane,
  • Xuewen Qian,
  • Fotis Lazarakis,
  • Julien De Rosny,
  • Dinh-Thuy Phan-Huy,
  • Osvaldo Simeone,
  • Rui Zhang,
  • Meroaune Debbah,
  • Geoffroy Lerosey,
  • Mathias Fink,
  • Sergei Tretyakov,
  • Shlomo Shamai

DOI
https://doi.org/10.1109/OJCOMS.2020.3002955
Journal volume & issue
Vol. 1
pp. 798 – 807

Abstract

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Reconfigurable intelligent surfaces (RISs) have the potential of realizing the emerging concept of smart radio environments by leveraging the unique properties of metamaterials and large arrays of inexpensive antennas. In this article, we discuss the potential applications of RISs in wireless networks that operate at high-frequency bands, e.g., millimeter wave (30-100 GHz) and sub-millimeter wave (greater than 100 GHz) frequencies. When used in wireless networks, RISs may operate in a manner similar to relays. The present paper, therefore, elaborates on the key differences and similarities between RISs that are configured to operate as anomalous reflectors and relays. In particular, we illustrate numerical results that highlight the spectral efficiency gains of RISs when their size is sufficiently large as compared with the wavelength of the radio waves. In addition, we discuss key open issues that need to be addressed for unlocking the potential benefits of RISs for application to wireless communications and networks.

Keywords