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Related papers: Channel Estimation for RIS-Empowered Multi-User MI…

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Intelligent surfaces comprising of cost effective, nearly passive, and reconfigurable unit elements are lately gaining increasing interest due to their potential in enabling fully programmable wireless environments. They are envisioned to…

Information Theory · Computer Science 2022-05-26 George C. Alexandropoulos , Evangelos Vlachos

Cell-free massive multiple-input multiple-output (MIMO) and reconfigurable intelligent surfaces (RISs) are two potential sixth-generation (6G) technologies. However, channel aging due to user mobility and electromagnetic interference (EMI)…

Information Theory · Computer Science 2025-02-27 Jun Qian , Chi Zhang , Ross Murch , Khaled B. Letaief

This paper investigates the performance of a two-timescale transmission design for uplink reconfigurable intelligent surface (RIS)-aided cell-free massive multiple-input multiple-output (CF-mMIMO) systems. We consider the Rician channel…

Signal Processing · Electrical Eng. & Systems 2023-08-07 Jianxin Dai , Jin Ge , Kangda Zhi , Cunhua Pan , Zaichen Zhang , Jiangzhou Wang , Xiaohu You

Although reconfigurable intelligent surface (RIS) is a promising technology for shaping the propagation environment, it consists of a single-layer structure within inherent limitations regarding the number of beam steering patterns. Based…

In this paper, we investigate a reconfigurable intelligent surface (RIS)-aided multiple-input single-output (MISO) system in the presence of electromagnetic interference (EMI) and channel aging with a Rician fading channel model between the…

Information Theory · Computer Science 2024-05-16 Taoyu Song , Enyu Shi , Yu Lu , Yiyang Zhu , Jiayi Zhang , Bo Ai

Multi-user integrated sensing and communication (ISAC) assisted by intelligent reflecting surface (IRS) has been recently investigated to provide a high spectral and energy efficiency transmission. This paper proposes a practical channel…

Signal Processing · Electrical Eng. & Systems 2024-04-09 Yu Liu , Ibrahim Al-Nahhal , Octavia A. Dobre , Fanggang Wang , Hyundong Shin

The plethora of wirelessly connected devices, whose deployment density is expected to largely increase in the upcoming sixth Generation (6G) of wireless networks, will naturally necessitate substantial advances in multiple access schemes.…

Information Theory · Computer Science 2024-10-29 Konstantinos D. Katsanos , Paolo Di Lorenzo , George C. Alexandropoulos

This paper proposes the joint design of reconfigurable intelligent surfaces (RIS) and zero-forcing (ZF) precoding for the downlink (DL) multiuser multiple-input single-output (MU-MISO) setup in millimeter-wave (mmWave) bands, where ZF is…

Signal Processing · Electrical Eng. & Systems 2026-05-13 Ainna Yue Moreno-Locubiche , Josep Vidal , Antonio Pascual-Iserte , Olga Muñoz

Due to the passive nature of Intelligent Reflecting Surface (IRS), channel estimation is a fundamental challenge in IRS-aided wireless networks. Particularly, as the number of IRS reflecting elements and/or that of IRS-served users…

Information Theory · Computer Science 2020-08-04 Xinrong Guan , Qingqing Wu , Rui Zhang

In this paper, we investigate a cascaded channel estimation method for a millimeter wave (mmWave) massive multiple-input multiple-output (MIMO) system aided by a reconfigurable intelligent surface (RIS) with the BS equipped with…

Information Theory · Computer Science 2024-01-17 Ruizhe Wang , Hong Ren , Cunhua Pan , Shi Jin , Petar Popovski , Jiangzhou Wang

Reconfigurable intelligent surface (RIS)-assisted cell-free (CF) multiple-input multiple-output (MIMO) networks can significantly enhance system performance. However, the extensive deployment of RIS elements imposes considerable channel…

Signal Processing · Electrical Eng. & Systems 2025-06-30 Hongqin Ke , Jindan Xu , Wei Xu , Chau Yuen , Zhaohua Lu

A reconfigurable intelligent surface (RIS) can be used to improve the channel gain between a base station (BS) and user equipment (UE), but only if its $N$ reflecting elements are configured properly. This requires accurate estimation of…

Signal Processing · Electrical Eng. & Systems 2022-05-24 Özlem Tuğfe Demir , Emil Björnson , Luca Sanguinetti

Reconfigurable intelligent surface (RIS) is a promising technology for future wireless communications due to its capability of optimizing the propagation environments. Nevertheless, in literature, there are few prototypes serving multiple…

Signal Processing · Electrical Eng. & Systems 2024-05-14 Zhibo Zhou , Haifan Yin , Li Tan , Ruikun Zhang , Kai Wang , Yingzhuang Liu

Reconfigurable intelligent surface (RIS) has been anticipated to be a novel cost-effective technology to improve the performance of future wireless systems. In this paper, we investigate a practical RIS-aided multiple-input-multiple-output…

Information Theory · Computer Science 2023-03-23 Jintao Wang , Shiqi Gong , Qingqing Wu , Shaodan Ma

The integration of electromagnetic metasurfaces into wireless communications enables intelligent control of the propagation environment. Recently, flexible intelligent metasurfaces (FIMs) have evolved beyond conventional reconfigurable…

Signal Processing · Electrical Eng. & Systems 2026-01-23 Ling He , Vaibhav Kumar , Anastasios Papazafeiropoulos , Miaowen Wen , Le-Nam Tran , Marwa Chafii

Reconfigurable Intelligent Surfaces (RIS) is a transformative technology with great potential in many applications in wireless communications and realizing the Internet of Everything at sixth generation (6G). In this study, we propose a…

Information Theory · Computer Science 2025-06-25 Xuejian Wei , Hui-Ming Wang

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

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

The emerging immersive and autonomous services have posed stringent requirements on both communications and localization. By considering the great potential of reconfigurable intelligent surface (RIS), this paper focuses on the joint…

Signal Processing · Electrical Eng. & Systems 2024-03-05 Yunfei Li , Yiting Luo , Xianda Wu , Zheng Shi , Shaodan Ma , Guanghua Yang

In this letter, we study efficient channel estimation and passive beamforming designs for a double-intelligent reflecting surface (IRS) aided single-user communication system, where a user communicates with an access point (AP) via the…

Information Theory · Computer Science 2020-08-27 Changsheng You , Beixiong Zheng , Rui Zhang