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Related papers: RIS-Aided Near-Field Channel Estimation under Mutu…

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We consider the problem of channel estimation in a multiple-input-multiple-output (MIMO) full-duplex (FD) wireless communication system assisted by a reconfigurable intelligent surface (RIS) with hardware impairments (HI) occurring at the…

Signal Processing · Electrical Eng. & Systems 2023-07-25 Alexander James Fernandes , Ioannis Psaromiligkos

This work considers a reconfigurable intelligent surface (RIS)-aided cell-free massive multiple-input multiple-output (MIMO) system with RIS spatial correlation and electromagnetic interference (EMI). We propose a two-phase channel…

Information Theory · Computer Science 2024-11-18 Jun Qian , Chi Zhang , Khaled B. Letaief , Ross Murch

We study the performance of a phase-noise impaired double reconfigurable intelligent surface (RIS)-aided multiuser (MU) multiple-input single-output (MISO) system under spatial correlation at both RISs and base-station (BS). The downlink…

Information Theory · Computer Science 2022-04-19 Zaid Abdullah , Anastasios Papazafeiropoulos , Steven Kisseleff , Symeon Chatzinotas , Bjorn Ottersten

Reconfigurable intelligent surface (RIS) has been widely discussed as new technology to improve wireless communication performance. Based on the unique design of RIS, its elements can reflect, refract, absorb, or focus the incoming waves…

Signal Processing · Electrical Eng. & Systems 2020-09-03 Salah Eddine Zegrar , Liza Afeef , Huseyin Arslan

This paper explores the integration of reconfigurable intelligent surfaces (RISs) into cell-free massive multiple-input-multiple-output (CF-mMIMO) networks operating in FR1 and FR3 frequency bands. We present a comprehensive framework for…

Signal Processing · Electrical Eng. & Systems 2026-04-21 Alejandro de la Fuente , Fernando Galindo , Uriel García-Bárbulo , Sandra-Noemy Arana-Alegre , Jan García-Morales

Reconfigurable intelligent surface (RIS) is envisioned to be an essential component of the paradigm for beyond 5G networks as it can potentially provide similar or higher array gains with much lower hardware cost and energy consumption…

Information Theory · Computer Science 2020-07-09 Hang Liu , Xiaojun Yuan , Ying-Jun Angela Zhang

This paper investigates the performance of downlink simultaneous transmitting and reflecting reconfigurable intelligent surface (STAR-RIS)-assisted cell-free (CF) massive multiple-input multiple-output (mMIMO) systems, where user equipments…

Information Theory · Computer Science 2023-12-01 Anastasios Papazafeiropoulos , Hien Quoc Ngo , Pandelis Kourtessis , Symeon Chatzinotas

Intelligent reflecting surfaces (IRSs) are regarded as promising enablers for future millimeter wave (mmWave) wireless communication, due to their ability to create favorable line-of-sight (LoS) propagation environments. In this paper, we…

Information Theory · Computer Science 2020-05-12 Tian Lin , Xianghao Yu , Yu Zhu , Robert Schober

This paper provides a theoretical framework for understanding the performance of reconfigurable intelligent surface (RIS)-aided massive multiple-input multiple-output (MIMO) with zero-forcing (ZF) detectors under imperfect channel state…

Information Theory · Computer Science 2021-11-03 Kangda Zhi , Cunhua Pan , Gui Zhou , Hong Ren , Maged Elkashlan , Robert Schober

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

Reconfigurable intelligent surfaces (RISs) have emerged as a promising technology for enhancing wireless communications through dense antenna arrays. Accurate channel estimation is critical to unlocking their full performance potential. To…

Information Theory · Computer Science 2025-10-21 Zijian Zhang , Mingyao Cui

Reconfigurable Intelligent Surfaces (RISs) have been recently considered as an energy-efficient solution for future wireless networks. Their dynamic and low-power configuration enables coverage extension, massive connectivity, and…

Information Theory · Computer Science 2020-11-30 Li Wei , Chongwen Huang , George C. Alexandropoulos , Zhaohui Yang , Chau Yuen , Zhaoyang Zhang

This chapter focuses on a hardware architecture for semi-passive Reconfigurable Intelligent Surfaces (RISs) and investigates its consideration for boosting the performance of Multiple-Input Multiple-Output (MIMO) communication systems. The…

Signal Processing · Electrical Eng. & Systems 2025-06-19 George C. Alexandropoulos , Konstantinos D. Katsanos , Evangelos Vlachos

Existing works mainly rely on the far-field planar-wave-based channel model to assess the performance of reconfigurable intelligent surface (RIS)-enabled wireless communication systems. However, when the transmitter and receiver are in…

Signal Processing · Electrical Eng. & Systems 2024-03-20 Hao Jiang , Wangqi Shi , Zaichen Zhang , Cunhua Pan , Qingqing Wu , Feng Shu , Ruiqi Liu , Jiangzhou Wang

We consider a multiple-input multiple-output (MIMO) channel in the presence of a reconfigurable intelligent surface (RIS). Specifically, our focus is on analyzing the spatial multiplexing gains in line-of-sight and low-scattering MIMO…

Information Theory · Computer Science 2023-01-10 Giulio Bartoli , Andrea Abrardo , Nicolo Decarli , Davide Dardari , Marco Di Renzo

In intelligent reflecting surface (IRS) assisted communication systems, the acquisition of channel state information (CSI) is a crucial impediment for achieving the beamforming gain of IRS because of the considerable overhead required for…

Information Theory · Computer Science 2020-06-25 Zhaorui Wang , Liang Liu , Shuguang Cui

In this paper, we utilize tools from stochastic geometry to estimate the interference propagation via reconfigurable intelligent surface (RIS) in the millimeter wave (mmWave, 30-300 GHz) band and specifically on the D band (110-170 GHz).…

Information Theory · Computer Science 2021-07-15 Joonas Kokkoniemi , Markku Juntti

Channel estimation in reconfigurable intelligent surface (RIS) assisted multiple input multiple output (MIMO) communication systems is challenging as pilots cannot be decoded at or transmitted from a RIS with only passive elements. We…

Signal Processing · Electrical Eng. & Systems 2021-03-22 Battu Deepak , R. S. Prasobh Sankar , Sundeep Prabhakar Chepuri

Reconfigurable intelligent surface (RIS) is a novel meta-material which can form a smart radio environment by dynamically altering reflection directions of the impinging electromagnetic waves. In the prior literature, the inter-RIS links…

Information Theory · Computer Science 2024-03-13 Kaizhe Xu , Jiajia Guo , Jun Zhang , Shi Jin , Shaodan Ma

Reconfigurable intelligent surface (RIS) is a newly-emerged technology that might fundamentally change how wireless networks are operated. Though extensively studied in recent years, the practical limitations of RIS are often neglected when…

Signal Processing · Electrical Eng. & Systems 2023-12-12 Parisa Ramezani , Yasaman Khorsandmanesh , Emil Björnson