Introduction edit
Reconfigurable intelligent surface (RIS) are a new class of smart materials and devices that have the ability to dynamically control the electromagnetic (EM) wave propagation in their vicinity. They are made of arrays of small, low-cost, passive elements, such as antennas, that can be independently controlled to manipulate the phase, amplitude, and polarization of the incident EM waves.
Technology Overview edit
RISs have the potential to revolutionize wireless communication and sensing systems[1] by enabling unprecedented control over the EM wave propagation environment[2]. They can be used to enhance the performance of wireless communication systems by creating desired signal patterns, such as beamforming[3], or by reducing interference and improving signal-to-noise ratio. They can also be used for sensing and imaging[4] applications by creating specific scattering patterns that can be used to extract information about the environment.
Integration and Smart Environments edit
One of the key advantages of RISs is their ability to adapt to the environment in real-time. This allows them to dynamically adjust their properties to optimize the performance of the wireless communication or sensing system. For example, in a wireless communication system, a RIS can be used to create a desired signal pattern that is optimized for the location of the receiver, even if the receiver is moving.
RISs can also be integrated into existing infrastructure, such as walls and ceilings, to create smart buildings[5]. In these applications, RISs can be used to control the propagation of EM waves inside the building, which can be used to improve wireless communication, reduce interference, and improve security[6].
Challenges and Future Directions edit
There are several challenges that must be overcome in order to fully realize the potential of RISs[7]. One of the main challenges is the design of efficient algorithms for controlling the RIS elements. These algorithms must be able to take into account the complex interactions between the RIS elements and the incident EM waves.
Another challenge is the design of low-cost and low-power control electronics for the RIS elements. This is particularly important for applications where the RISs must be integrated into existing infrastructure, as the cost and power consumption of the control electronics must be kept to a minimum[8]
Finally, there are also several challenges related to the integration of RISs into existing wireless communication and sensing systems[9]. This includes the design of new modulation and coding schemes, as well as the development of new protocols for controlling the RIS elements.
References edit
- ^ Alexandropoulos, G. C.; Shlezinger, N.; del Hougne, P. (June 2021). "Reconfigurable Intelligent Surfaces for Rich Scattering Wireless Communications: Recent Experiments, Challenges, and Opportunities". IEEE Communications Magazine. 59 (6): 28–34. doi:10.1109/MCOM.001.2001117.
- ^ Di Renzo, M.; Zappone, A.; Debbah, M.; Slim Aliouni, M.; Slim Aliouni, M.; Yuen, C. (November 2020). "Smart Radio Environments Empowered by Reconfigurable Intelligent Surfaces: How It Works, State of Research, and The Road Ahead". IEEE Journal on Selected Areas in Communications. 38 (11): 2450–2525. doi:10.1109/JSAC.2020.3007211.
- ^ Yan, W.; Yuan, X.; He, Z. -Q.; Kuai, X. (August 2020). "Passive Beamforming and Information Transfer Design for Reconfigurable Intelligent Surfaces Aided Multiuser MIMO Systems". IEEE Journal on Selected Areas in Communications. 38 (8): 1793–1808. doi:10.1109/JSAC.2020.3000811.
- ^ Hu, J.; Zhang, H.; Di, B.; Li, L.; Bian, K.; Song, L. (November 2020). "Reconfigurable Intelligent Surface Based RF Sensing: Design, Optimization, and Implementation". IEEE Journal on Selected Areas in Communications. 38 (11): 2700–2716. doi:10.1109/JSAC.2020.3007041.
- ^ Kisseleff, S.; Martins, W. A.; Al-Hraishawi, H.; Chatzinotas, S.; Ottersten, B. (2020). "Reconfigurable Intelligent Surfaces for Smart Cities: Research Challenges and Opportunities". IEEE Open Journal of the Communications Society. 1: 1781–1797. doi:10.1109/OJCOMS.2020.3036839.
- ^ Strinati, E. C.; Alexandropoulos, G. C.; Sciancalepore, V.; Di Renzo, M.; Wymeersch, H.; Phan-Huy, D.-T.; Crozzoli, M.; D'Errico, R.; De Carvalho, E. (October 2021). "Reconfigurable, Intelligent, and Sustainable Wireless Environments for 6G Smart Connectivity". IEEE Communications Magazine. 59 (10): 99–105. doi:10.1109/MCOM.001.2100070.
- ^ ElMossallamy, M. A.; Zhang, H.; Song, L.; Seddik, K. G.; Han, Z.; Li, G. Y. (September 2020). "Reconfigurable Intelligent Surfaces for Wireless Communications: Principles, Challenges, and Opportunities". IEEE Transactions on Cognitive Communications and Networking. 6 (3): 990–1002. doi:10.1109/TCCN.2020.2992604.
- ^ Liu, K.; Zhang, Z. (2021). On The Energy-Efficiency Fairness of Reconfigurable Intelligent Surface-Aided Cell-Free Network. 2021 IEEE 93rd Vehicular Technology Conference (VTC2021-Spring). Helsinki, Finland. pp. 1–6. doi:10.1109/VTC2021-Spring51267.2021.9448858.
- ^ Pan, C.; Liang, Y.-C.; Di Renzo, M.; Swindlehurst, A. Lee; Sciancalepore, V. (2022). "Ieee Access Special Section Editorial: Reconfigurable Intelligent Surface Aided Communications for 6G and Beyond". IEEE Access. 10: 19443–19446. doi:10.1109/ACCESS.2022.3147698.