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Related papers: RIS-Assisted Beamfocusing in Near-Field IoT Commun…

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The technology of reconfigurable intelligent surfaces (RIS) has been showing promising potential in a variety of applications relying on Beyond-5G networks. Reconfigurable intelligent surface (RIS) can indeed provide fine channel…

Signal Processing · Electrical Eng. & Systems 2023-03-28 Moustafa Rahal , Benoit Denis , Kamran Keykhosravi , Musa Furkan Keskin , Bernard Uguen , George C. Alexandropoulos , Henk Wymeersch

Reconfigurable intelligent surfaces (RISs) have attracted increasing interest due to their ability to improve the coverage, reliability, and energy efficiency of millimeter wave (mmWave) communication systems. However, designing the RIS…

Signal Processing · Electrical Eng. & Systems 2022-11-15 Shuaifeng Jiang , Ahmed Hindy , Ahmed Alkhateeb

In this work, we tackle the problem of beampattern design for a transmit system employing a large reconfigurable intelligent surface (RIS) to redirect radio frequency signals emitted by a few active antennas (sources). We begin by…

Signal Processing · Electrical Eng. & Systems 2025-07-15 Ciro D'Elia , Emanuele Grossi , Luca Venturino

Reconfigurable Intelligent Surfaces (RIS) or Intelligent Reflecting Surfaces (IRS) are metasurfaces that can be deployed in various places in wireless environments to make these environments controllable and reconfigurable. In this paper,…

Information Theory · Computer Science 2020-01-22 S. Mohammad Razavizadeh , Tommy Svensson

In this work, we propose a beam training codebook for Reconfigurable Intelligent Surface (RIS) assisted mmWave uplink communication. Beam training procedure is important to establish a reliable link between user node and Access point (AP).…

Signal Processing · Electrical Eng. & Systems 2021-07-30 Chandradeep Singh , Kamal Singh , K. H. Liu

Reconfigurable intelligent surface (RIS) is a type of wireless communication technology that uses a reconfigurable surface, such as a wall or building that is able to adjust its properties by an integrated optimization algorithm in order to…

Applied Physics · Physics 2023-09-25 Emanuel Colella , Luca Bastianelli , Franco Moglie , Valter Mariani Primiani

Active reconfigurable intelligent surface (RIS) emerges as an effective technique to resist the double-fading attenuation of passive RIS. By embedding with power harvesting function, it further evolves to zero-power active RIS, which can…

Information Theory · Computer Science 2025-10-17 Xiao Zheng , Wenchi Cheng , Jingqing Wang , Zhuohui Yao , Jiangzhou Wang

A near-field wideband beamforming scheme is investigated for reconfigurable intelligent surface (RIS) assisted multiple-input multiple-output (MIMO) systems, in which a deep learning-based end-to-end (E2E) optimization framework is proposed…

Information Theory · Computer Science 2025-01-30 Ji Wang , Jian Xiao , Yixuan Zou , Wenwu Xie , Yuanwei Liu

The spectrum shift from the sub-6G band to the high-frequency band has posed an ever-increasing demand on the paradigm shift from narrowband beamforming to wideband beamforming. Despite recent research efforts, the problem of wideband…

Computational Engineering, Finance, and Science · Computer Science 2024-07-09 Xiaowei Qian , Xiaoling Hu , Chenxi Liu , Mugen Peng

In this paper, we present a low overhead beam management approach for near-field millimeter-wave multi-antenna communication systems enabled by Reconfigurable Intelligent Surfaces (RISs). We devise a novel variable-width hierarchical…

Information Theory · Computer Science 2022-03-30 George C. Alexandropoulos , Vahid Jamali , Robert Schober , H. Vincent Poor

The advantages of millimeter-wave and large antenna arrays technologies for accurate wireless localization received extensive attentions recently. However, how to further improve the accuracy of wireless localization, even in the case of…

Information Theory · Computer Science 2020-09-17 Yiming Liu , Erwu Liu , Rui Wang

Reconfigurable intelligent surfaces, with their large number of antennas, offer an interesting opportunity for high spatial-resolution imaging. In this paper, we propose a novel RIS-aided integrated imaging and communication system that can…

Signal Processing · Electrical Eng. & Systems 2024-01-30 Hao Luo , Ahmed Alkhateeb

Reconfigurable intelligent surfaces (RIS) are expected to play an important role in future wireless communication systems. These surfaces typically rely on their reflection beamforming codebooks to reflect and focus the signal on the target…

Information Theory · Computer Science 2021-10-06 Yu Zhang , Ahmed Alkhateeb

Future wireless communications are promising to support ubiquitous connections and high data rates with cost-effective devices. Benefiting from the energy-efficient elements with low cost, reconfigurable intelligent surface (RIS) emerges as…

Information Theory · Computer Science 2024-07-19 Xiao Zheng , Wenchi Cheng , Jingqing Wang , Wei Zhang

Reconfigurable intelligent surface (RIS)-aided near-field communications is investigated. First, the necessity of investigating RIS-aided near-field communications and the advantages brought about by the unique spherical-wave-based…

Information Theory · Computer Science 2024-03-05 Xidong Mu , Jiaqi Xu , Yuanwei Liu , Lajos Hanzo

In this chapter, we investigate the mathematical foundation of the modeling and design of reconfigurable intelligent surfaces (RIS) in both the far- and near-field regimes. More specifically, we first present RIS-assisted wireless channel…

Signal Processing · Electrical Eng. & Systems 2025-10-16 Mohamadreza Delbari , George C. Alexandropoulos , Robert Schober , Vahid Jamali

Reconfigurable Intelligent Surface (RIS) has becoming a useful tool in future wireless communication systems for close-distance communication network. This paper we use Reconfigurable Intelligent Surface (RIS) for downlink multi-user…

Information Theory · Computer Science 2021-02-02 RuiTianYi Lu

Exploiting wavefront curvature enables localization with limited infrastructure and hardware complexity. With the introduction of reconfigurable intelligent surfaces (RISs), new opportunities arise, in particular when the RIS is functioning…

Reconfigurable intelligent surface (RIS) is an emerging technique employing metasurface to reflect the signal from the source node to the destination node. By smartly reconfiguring the electromagnetic (EM) properties of the metasurface and…

Information Theory · Computer Science 2022-06-30 Qi Gu , Dan Wu , Xin Su , Hanning Wang , Jingyuan Cui , Yifei Yuan

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
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