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Related papers: Adaptive Beamforming Design for mmWave RIS-Aided J…

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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

In this paper, a novel reconfigurable intelligent surface (RIS)-assisted multiple-input multiple-output (MIMO) symbiotic radio (SR) system is proposed, in which an RIS, operating as a secondary transmitter (STx), sends messages to a…

Signal Processing · Electrical Eng. & Systems 2021-03-31 Qianqian Zhang , Ying-Chang Liang , H. Vincent Poor

We consider a reconfigurable intelligent surface (RIS) assisted multiple-input multiple-output (MIMO) system in the presence of scattering objects. The MIMO transmitter and receiver, the RIS, and the scattering objects are modeled as…

Information Theory · Computer Science 2023-09-19 H. El Hassani , X. Qian , S. Jeong , N. S. Perović , M. Di Renzo , P. Mursia , V. Sciancalepore , X. Costa-Pérez

By reconfiguring the propagation environment of electromagnetic waves artificially, reconfigurable intelligent surfaces (RISs) have been regarded as a promising and revolutionary hardware technology to improve the energy and spectrum…

Signal Processing · Electrical Eng. & Systems 2020-06-03 Huiyuan Yang , Xiaojun Yuan , Jun Fang , Ying-Chang Liang

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

A reconfigurable intelligent surface (RIS) is a planar surface that can enhance the quality of communication by providing control over the communication environment. Reflection optimization is one of the pivotal challenges in RIS setups.…

Information Theory · Computer Science 2024-11-26 Seyedkhashayar Hashemi , Masoud Ardakani , Hai Jiang

Reconfigurable intelligent surfaces (RISs) have been deemed as one of potential components of future wireless communication systems because they can adaptively manipulate the wireless propagation environment with low-cost passive devices.…

Signal Processing · Electrical Eng. & Systems 2022-03-23 Yanan Ma , Rang Liu , Yang Liu , Ming Li , Qian Liu

This paper investigates the two-timescale transmission design for reconfigurable intelligent surface (RIS)-aided massive multiple-input multiple-output (MIMO) systems, where the beamforming at the base station (BS) is adapted to the…

Intelligent reflecting surface (IRS) is envisioned to have abundant applications in future wireless networks by smartly reconfiguring the signal propagation for performance enhancement. Specifically, an IRS consists of a large number of…

Information Theory · Computer Science 2018-09-13 Qingqing Wu , Rui Zhang

This paper studies a symbiotic system in which a reconfigurable intelligent surface (RIS) assists a radar transmitter while conveying information to a reader via backscattering. The RIS is partitioned into subarrays that redirect the radar…

Signal Processing · Electrical Eng. & Systems 2026-05-05 Mehri Nikzad , Luca Venturino , Emanuele Grossi , Xiaodong Wang

Intelligent reflecting surface (IRS) that enables the control of wireless propagation environment has recently emerged as a promising cost-effective technology for boosting the spectrum and energy efficiency in future wireless communication…

Information Theory · Computer Science 2020-02-25 Samith Abeywickrama , Rui Zhang , Qingqing Wu , Chau Yuen

Reconfigurable surface (RS) has been shown to be an effective solution for improving wireless communication links in general multi-user multiple-input multiple-output (MU-MIMO) setting. Current research efforts have been largely directed…

Information Theory · Computer Science 2023-10-31 Juan Vidal Alegria , Joao Vieira , Fredrik Rusek

Most research works on reconfigurable intelligent surfaces (RIS) rely on idealized models of the reflection coefficients, i.e., uniform reflection amplitude for any phase and sufficient phase shifting capability. In practice however, such…

Signal Processing · Electrical Eng. & Systems 2024-04-17 Lin Cao , Haifan Yin , Li Tan , Xilong Pei

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 a holographic MIMO surface composed of a large number of passive elements that can induce adjustable phase shifts to the impinging waves. By creating virtual line-of-sight (LOS) paths between…

Signal Processing · Electrical Eng. & Systems 2023-04-06 Mehdi Haghshenas , Parisa Ramezani , Maurizio Magarini , Emil Björnson

Intelligent reflecting surfaces (IRSs) have received considerable attention from the wireless communications research community recently. In particular, as low-cost passive devices, IRSs enable the control of the wireless propagation…

Information Theory · Computer Science 2019-04-30 Xianghao Yu , Dongfang Xu , Robert Schober

We consider the optimization of beyond diagonal reconfigurable intelligent surface (BD-RIS)-aided multi-user (MU) cell-free (CF)-massive multiple-input multiple-output (mMIMO) systems, where the propagation environment design achieved…

Signal Processing · Electrical Eng. & Systems 2026-05-18 Iván Alexander Morales Sandoval , Marko Fidanovski , Hyeon Seok Rou , Giuseppe Thadeu Freitas de Abreu , Emil Björnson

Reconfigurable intelligent surfaces (RISs) have emerged as a promising solution that can provide dynamic control over the propagation of electromagnetic waves. The RIS technology is envisioned as a key enabler of sixth-generation networks…

Signal Processing · Electrical Eng. & Systems 2025-02-26 Ishan Koralege , Arthur S. de Sena , Nurul H. Mahmood , Farjam Karim , Dimuthu Lesthuruge , Samitha Gunarathne

In reconfigurable intelligent surface (RIS) aided millimeter-wave (mmWave) communication systems, in order to overcome the limitation of the conventional channel state information (CSI) acquisition techniques, this paper proposes a location…

Information Theory · Computer Science 2024-10-28 Zhe Xing , Rui Wang , Xiaojun Yuan , Jun Wu

Cell-free systems can effectively eliminate the inter-cell interference by enabling multiple base stations (BSs) to cooperatively serve users without cell boundaries at the expense of high costs of hardware and power sources due to the…

Information Theory · Computer Science 2020-11-18 Yutong Zhang , Boya Di , Hongliang Zhang , Jinlong Lin , Yonghui Li , Lingyang Song