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Related papers: Far- versus Near-Field RIS Modeling and Beam Desig…

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Reconfigurable intelligent surface (RIS) technology is a promising solution to improve the performance of existing wireless communications. To achieve its cost-effectiveness advantage, there inevitably exist certain hardware impairments in…

Signal Processing · Electrical Eng. & Systems 2024-01-17 Yiming Liu , Rui Wang , Zhu Han

Reconfigurable intelligent surfaces (RISs) are envisioned to be a disruptive wireless communication technique that is capable of reconfiguring the wireless propagation environment. In this paper, we study a free-space RIS-assisted…

Information Theory · Computer Science 2022-09-19 Xin Cheng , Yan Lin , Weiping Shi , Jiayu Li , Cunhua Pan , Feng Shu , Yongpeng Wu , Jiangzhou Wang

Wireless communication systems have almost exclusively operated in the far-field of antennas and antenna arrays, which is conventionally characterized by having propagation distances beyond the Fraunhofer distance. This is natural since the…

Information Theory · Computer Science 2021-12-09 Emil Björnson , Özlem Tugfe Demir , Luca Sanguinetti

Reconfigurable intelligent surfaces (RISs) enable programmable control of the wireless propagation environment and are key enablers for future networks. Beyond-diagonal RIS (BD-RIS) architectures enhance conventional RIS by interconnecting…

Information Theory · Computer Science 2026-05-04 Matteo Nerini , Zheyu Wu , Shanpu Shen , Bruno Clerckx

In this letter, we study the beamforming design for channel estimation of multi-functional reconfigurable intelligent surface (MF-RIS)-aided multi-user communications that supports simultaneous signal reflection, refraction, and…

Signal Processing · Electrical Eng. & Systems 2025-01-22 Zaihao Pan , Wen Wang , Gaofeng Nie , Ailing Zheng , Wanli Ni

This correspondence investigates the novel fluid antenna system (FAS) technology, combining with reconfigurable intelligent surface (RIS) for wireless communications, where a base station (BS) communicates with a FAS-enabled user with the…

Signal Processing · Electrical Eng. & Systems 2024-08-27 Junteng Yao , Jianchao Zheng , Tuo Wu , Ming Jin , Chau Yuen , Kai-Kit Wong , Fumiyuki Adachi

Reconfigurable Intelligent Surfaces (RIS) constitute a promising technology that could fulfill the extreme performance and capacity needs of the upcoming 6G wireless networks, by offering software-defined control over wireless propagation…

Enabling multi-target sensing in near-field integrated sensing and communication (ISAC) systems is a key challenge, particularly when line-of-sight paths are blocked. This paper proposes a beamforming framework that leverages a…

Signal Processing · Electrical Eng. & Systems 2025-09-11 Hang Ruan , Homa Nikbakht , Ruizhi Zhang , Honglei Chen , Yonina C. Eldar

In this paper, we propose a multi-RIS-aided wireless imaging framework in 3D facing the distributed placement of multi-sensor networks. The system creates a randomized reflection pattern by adjusting the RIS phase shift, enabling the…

Image and Video Processing · Electrical Eng. & Systems 2023-11-21 Fuhai Wang , Chun Wang , Rujing Xiong , Zhengyu Wang , Tiebin Mi , Robert Caiming Qiu

Reconfigurable intelligent surface (RIS) is considered to be an energy-efficient approach to reshape the wireless environment for improved throughput. Its passive feature greatly reduces the energy consumption, which makes RIS a promising…

Information Theory · Computer Science 2020-01-20 Keke Ying , Zhen Gao , Shanxiang Lyu , Yongpeng Wu , Hua Wang , Mohamed-Slim Alouini

Reconfigurable intelligent surface (RIS) has gained much traction due to its potential to manipulate the propagation environment via nearly-passive reconfigurable elements. In our previous work, we have analyzed and proposed a beyond…

Signal Processing · Electrical Eng. & Systems 2023-03-29 Hongyu Li , Shanpu Shen , Bruno Clerckx

Reconfigurable Intelligent Surfaces (RISs) are recently attracting a wide interest due to their capability of tuning wireless propagation environments in order to increase the system performance of wireless networks. In this paper, a…

Information Theory · Computer Science 2021-03-23 Stefano Buzzi , Carmen D'Andrea , Alessio Zappone , Maria Fresia , Yong-Ping Zhang , Shulan Feng

Reconfigurable Intelligent Surfaces (RIS) are an emerging technology that can be used to reconfigure the propagation environment to improve cellular communication link rates. RIS, which are thin metasurfaces composed of discrete elements,…

Signal Processing · Electrical Eng. & Systems 2020-11-11 Pooja Nuti , Brian L. Evans

A reconfigurable intelligent surface (RIS) is commonly made of low-cost passive and reflective meta-materials with excellent beam steering capabilities. It is applied to enhance wireless communication systems as a customizable signal…

Signal Processing · Electrical Eng. & Systems 2024-07-16 Kun Chen-Hu , Petar Popovski

In this paper, we propose and study a multi-functional reconfigurable intelligent surface (MF-RIS) architecture. In contrast to conventional single-functional RIS (SF-RIS) that only reflects signals, the proposed MF-RIS simultaneously…

Signal Processing · Electrical Eng. & Systems 2023-10-05 Wen Wang , Wanli Ni , Hui Tian , Yonina C. Eldar , Rui Zhang

This paper develops fundamental bounds for localization in orthogonal frequency division multiplexing (OFDM) systems aided by reconfigurable intelligent surfaces (RISs). Specifically, we start from the assumption that the position and…

Signal Processing · Electrical Eng. & Systems 2023-08-22 Don-Roberts Emenonye , Harpreet S. Dhillon , R. Michael Buehrer

Despite the growing interest in the integration of reconfigurable intelligent surfaces (RIS) into next-generation wireless communications systems, a critical gap remains in understanding what the dimensions of an RIS must be to provide…

Signal Processing · Electrical Eng. & Systems 2025-06-10 Emre Arslan , Ahmet Faruk Coskun

Optimization of Reconfigurable Intelligent Surfaces (RIS) via a previously introduced method is effective, but time-consuming, because multiport impedance or scatter matrices are required for each transmitter and receiver position, which…

Optimization and Control · Mathematics 2025-01-31 Hans-Dieter Lang , Michel A. Nyffenegger , Heinz Mathis , Xingqi Zhang

Recent considerations for reconfigurable intelligent surfaces (RISs) assume that RISs can convey information by reflection without the need of transmit radio frequency chains, which, however, is a challenging task. In this paper, we propose…

Information Theory · Computer Science 2020-08-07 Shaoe Lin , Beixiong Zheng , George C. Alexandropoulos , Miaowen Wen , Marco Di Renzo , Fangjiong Chen

This paper investigates a modular beamforming framework for reconfigurable intelligent surface (RIS)-aided multi-user (MU) communications in the near-field regime, built upon a novel antenna architecture integrating an active multi-antenna…

Signal Processing · Electrical Eng. & Systems 2025-08-13 Giulia Torcolacci , Malte Schellmann , Davide Dardari