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Related papers: RIS-Aided Cell-Free Massive MIMO: Performance Anal…

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The performance of wireless communication systems is fundamentally constrained by random and uncontrollable wireless channels. Recently, reconfigurable intelligent surfaces (RIS) has emerged as a promising solution to enhance wireless…

Signal Processing · Electrical Eng. & Systems 2023-12-29 Xiaohao Mo , Lin Gui , Kai Ying , Xichao Sang , Xiaqing Diao

Recently, the so-called cell-free (CF) Massive MIMO architecture has been introduced, wherein a very large number of distributed access points (APs) simultaneously and jointly serve a much smaller number of mobile stations (MSs). The paper…

Information Theory · Computer Science 2018-03-07 Stefano Buzzi , Carmen D'Andrea , Alessio Zappone

Recently, reconfigurable intelligent surfaces (RIS) have attracted a lot of attention due to their capability of extending cell coverage by reflecting signals toward the receiver. In this letter, we analyze the coverage of a downlink…

Information Theory · Computer Science 2020-09-18 Shuhao Zeng , Hongliang Zhang , Boya Di , Zhu Han , Lingyang Song

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 2020-12-08 Huiyuan Yang , Xiaojun Yuan , Jun Fang , Ying-Chang Liang

In this chapter, using statistical physics methods, asymptotic closed-form expressions for the mean and variance of the mutual information for a multi-antenna transmitter-receiver pair in the presence of multiple Reconfigurable Intelligent…

Information Theory · Computer Science 2025-07-23 Aris L. Moustakas , George C. Alexandropoulos

This letter studies the performance of reconfigurable intelligent surface (RIS)-aided communications for a fluid antenna system (FAS) enabled receiver. Specifically, a fixed singleantenna base station (BS) transmits information through a…

Information Theory · Computer Science 2024-02-27 Farshad Rostami Ghadi , Kai-Kit Wong , Wee Kiat New , Hao Xu , Ross Murch , Yangyang Zhang

This paper addresses the problem of scalability for a cell-free massive MIMO (CF-mMIMO) system that performs integrated sensing and communications (ISAC). Specifically, the case where a large number of access points (APs) are deployed to…

Information Theory · Computer Science 2024-06-10 Stefano Buzzi , Carmen D'Andrea , Sergi Liesegang

In this paper, we consider the robust beamforming design in a reconfigurable intelligent surface (RIS)-aided cell-free (CF) system considering the channel state information (CSI) uncertainties of both the direct channels and cascaded…

Information Theory · Computer Science 2023-05-10 Jiacheng Yao , Jindan Xu , Wei Xu , Derrick Wing Kwan Ng , Chau Yuen , Xiaohu You

The advent of Reconfigurable Intelligent Surfaces (RISs) in wireless communication networks unlocks the way to support high frequency radio access (e.g. in millimeter wave) while overcoming their sensitivity to the presence of deep fading…

Information Theory · Computer Science 2022-05-31 Fatima Ezzahra Airod , Mattia Merluzzi , Paolo Di Lorenzo , Emilio Calvanese Strinati

In this paper, we study surface-based communication systems based on different levels of channel state information for system optimization. We analyze the system performance in terms of rate and degrees of freedom (DoF). We show that the…

Substantially increasing wireless traffic and extending serving coverage is required with the advent of sixth-generation (6G) wireless communication networks. Reconfigurable intelligent surface (RIS) is widely considered as a promising…

Information Theory · Computer Science 2023-04-27 Chia-Jou Ku , Li-Hsiang Shen , Kai-Ten Feng

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

The concept of reconfigurable intelligent surface (RIS) has been proposed to change the propagation of electromagnetic waves, e.g., reflection, diffraction, and refraction. To accomplish this goal, the phase values of the discrete RIS units…

Signal Processing · Electrical Eng. & Systems 2019-11-11 Jiguang He , Henk Wymeersch , Tachporn Sanguanpuak , Olli Silvén , Markku Juntti

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

Cell-free massive multiple-input multiple-output (MIMO) employs a large number of distributed access points (APs) to serve a small number of user equipments (UEs) via the same time/frequency resource. Due to the strong macro diversity gain,…

Information Theory · Computer Science 2021-11-23 Jiayi Zhang , Jing Zhang , Derrick Wing Kwan Ng , Shi Jin , Bo Ai

By leveraging the waveform superposition property of the multiple access channel, over-the-air computation (AirComp) enables the execution of digital computations through analog means in the wireless domain, leading to faster processing and…

Information Theory · Computer Science 2025-08-22 Meng Hua , Chenghong Bian , Haotian Wu , Deniz Gündüz

We consider a multi-user multiple-input single-output (MISO) communications system which is assisted by a hybrid active-passive reconfigurable intelligent surface (RIS). Unlike conventional passive RISs, hybrid RIS is equipped with a few…

Information Theory · Computer Science 2022-03-22 Nhan Thanh Nguyen , Van-Dinh Nguyen , Qingqing Wu , Antti Tolli , Symeon Chatzinotas , Markku Juntti

Reconfigurable intelligent surfaces (RIS) as an effective technique for intelligently manipulating channel paths through reflection to serve desired users. Full-duplex (FD) systems, enabling simultaneous transmission and reception from a…

Information Theory · Computer Science 2023-11-08 Li-Hsiang Shen , Chia-Jou Ku , Kai-Ten Feng

In this paper, for a single-input multiple-output (SIMO) system aided by a passive reconfigurable intelligent surface (RIS), the joint transmission accomplished by the single transmit antenna and the RIS with multiple controllable…

Information Theory · Computer Science 2023-11-27 Ru-Han Chen , Jing Zhou , Yonggang Zhu , Kai Zhang

Reconfigurable intelligent surfaces (RISs) are considered a promising technology for boosting the coverage and for enhancing the spectral efficiency of wireless systems, as well as for taming the wireless environment. The potential benefits…

Information Theory · Computer Science 2021-11-23 Bjorn Sihlbom , Marios I. Poulakis , Marco Di Renzo