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Related papers: Active RIS-Aided Massive MIMO Uplink Systems with …

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In this paper, the problem of sum-rate maximization for an active reconfigurable intelligent surface (RIS) assisted downlink rate-splitting multiple access (RSMA) transmission system is studied. In the considered model, the active RIS is…

Information Theory · Computer Science 2023-01-31 Xinhao Li , Tao Wang , Haonan Tong , Zhaohui Yang , Yijie Mao , Changchuan Yin

This paper considers Cell-Free Massive Multiple Input Multiple Output (MIMO) systems with the assistance of an RIS for enhancing the system performance. Distributed maximum-ratio combining (MRC) is considered at the access points (APs). We…

Information Theory · Computer Science 2021-09-17 Trinh Van Chien , Hien Quoc Ngo , Symeon Chatzinotas , Marco Di Renzo , Björn Ottersten

A cell-free network merged with active reconfigurable reflecting surfaces (RIS) is investigated in this paper. Based on the imperfect channel state information (CSI), the aggregated channel from the user to the access point (AP) is…

Signal Processing · Electrical Eng. & Systems 2024-02-23 Mahdi Eskandari , Huiling Zhu , Jiangzhou Wang

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) are passive or semi-passive heterogeneous metasurfaces and consist of many tunable elements. RIS is gaining momentum as a promising new technology to enable transforming the propagation environment…

Signal Processing · Electrical Eng. & Systems 2022-01-06 Pooja Nuti , Elyes Balti , Brian L. Evans

Reconfigurable Intelligent Surfaces (RIS) represent a transformative technology for sixth-generation (6G) wireless communications, but it suffers from a significant limitation, namely the double-fading attenuation. Active RIS has emerged as…

Information Theory · Computer Science 2025-04-23 Yang Cao , Wenchi Cheng , Jingqing Wang , Wei Zhang

This paper considers the application of reconfigurable intelligent surfaces (RISs) (a.k.a. intelligent reflecting surfaces (IRSs)) to assist multiuser multiple-input multiple-output (MIMO) uplink transmission from several multi-antenna user…

Information Theory · Computer Science 2021-09-14 Li You , Jiayuan Xiong , Yufei Huang , Derrick Wing Kwan Ng , Cunhua Pan , Wenjin Wang , Xiqi Gao

Reconfigurable intelligent surface (RIS) is known as a promising technology to improve the performance of wireless communication networks, which has been extensively studied. Movable antenna (MA) is a novel technology that fully exploits…

Signal Processing · Electrical Eng. & Systems 2023-11-14 Yunan Sun , Hao Xu , Chongjun Ouyang , Hongwen Yang

Reconfigurable intelligent surfaces (RIS) is a promising solution to build a programmable wireless environment via steering the incident signal in fully customizable ways with reconfigurable passive elements. In this paper, we consider a…

Signal Processing · Electrical Eng. & Systems 2019-12-30 Huayan Guo , Ying-Chang Liang , Jie Chen , Erik G. Larsson

In this paper, the problem of maximizing the sum-rate is addressed for a multi-user uplink scenario that is assisted by an active reconfigurable intelligent surface (RIS). The maximization is achieved by optimizing the beamforming at the…

Signal Processing · Electrical Eng. & Systems 2026-04-06 Mohamed Shalma , Engy Maher , Ahmed El-Mahdy

This paper investigates reconfigurable intelligent surface (RIS)-aided frequency division duplexing (FDD) communication systems. Since the downlink and uplink signals are simultaneously transmitted in FDD, the phase shifts at the RIS should…

Information Theory · Computer Science 2024-01-23 Gyoseung Lee , Hyeongtaek Lee , Donghwan Kim , Jaehoon Chung , A. Lee. Swindlehurst , Junil Choi

Cell-Free Massive multiple-input multiple-output (MIMO) and reconfigurable intelligent surface (RIS) are two promising technologies for application to beyond-5G networks. This paper considers Cell-Free Massive MIMO systems with the…

Information Theory · Computer Science 2021-12-20 Trinh Van Chien , Hien Quoc Ngo , Symeon Chatzinotas , Marco Di Renzo , Björn Ottersten

Practical hardware limitations often impose a reduced number of available phase shifts at the elements of a reconfigurable intelligent surface (RIS). Most works often assume continuous phase-shits at the RIS elements for the transmit and…

Information Theory · Computer Science 2023-04-20 Nuno Souto

Reconfigurable intelligent surfaces (RISs) represent a new technology that can shape the radio wave propagation and thus offers a great variety of possible performance and implementation gains. Motivated by this, we investigate the…

Information Theory · Computer Science 2021-09-06 Nemanja Stefan Perović , Le-Nam Tran , Marco Di Renzo , Mark F. Flanagan

Reconfigurable intelligent surfaces (RISs) have huge potential to improve spectral and energy efficiency in future wireless systems at a minimal cost. However, early prototype results indicate that deploying hundreds or thousands of…

Signal Processing · Electrical Eng. & Systems 2024-12-12 Eduard E. Bahingayi , Nemanja Stefan Perović , Le-Nam Tran

Reconfigurable intelligent surface (RIS) technology holds immense potential for increasing the performance of wireless networks. Therefore, RIS is also regarded as one of the solutions to address communication challenges in high-mobility…

Signal Processing · Electrical Eng. & Systems 2025-08-22 Hanwen Hu , Jiancheng An , Lu Gan , Chau Yuen

Smart radio environments aided by reconfigurable intelligent reflecting surfaces (RIS) have attracted much research attention recently. We propose a joint optimization strategy for beamforming, RIS phases, and power allocation to maximize…

Information Theory · Computer Science 2022-08-02 Athira Subhash , Abla Kammoun , Ahmed Elzanaty , Sheetal Kalyani , Yazan H. Al-Badarneh , Mohamed-Slim Alouini

The uplink performance of massive multiple-input-multiple-output (MIMO) systems where the base stations (BS) employ low-resolution analog-to-digital converters (ADCs) is analyzed. A high performance MMSE receiver that takes both additive…

Signal Processing · Electrical Eng. & Systems 2017-11-30 Chao Wei , Zaichen Zhang

This letter investigates the reconfigurable intelligent surface (RIS)-aided massive multiple-input multiple-output (MIMO) systems with a two-timescale design. First, the zero-forcing (ZF) detector is applied at the base station (BS) based…

Information Theory · Computer Science 2021-11-18 Kangda Zhi , Cunhua Pan , Hong Ren , Kezhi Wang

This work studies a low-complexity design for reconfigurable intelligent surface (RIS)-aided multiuser multiple-input multiple-output systems. The base station (BS) applies receive antenna selection to connect a subset of its antennas to…

Signal Processing · Electrical Eng. & Systems 2022-12-29 Chongjun Ouyang , Ali Bereyhi , Saba Asaad , Ralf R. Müller , Hongwen Yang