725 citations · 3k across the 227 of their papers we have counts for
47 papers · 1 filter
RIS-Enabled and Access-Point-Free Simultaneous Radio Localization and Mapping
Hyowon Kim, Hui Chen, Musa Furkan Keskin +5
In the upcoming sixth generation (6G) of wireless communication systems, reconfigurable intelligent surfaces~(RISs) are regarded as one of the promising technological enablers, whi…
Counteracting Eavesdropper Attacks Through Reconfigurable Intelligent Surfaces: A New Threat Model and Secrecy Rate Optimization
George C. Alexandropoulos, Konstantinos D. Katsanos, Miaowen Wen +1
The potential of Reconfigurable Intelligent Surfaces (RISs) for energy-efficient and performance-boosted wireless communications is recently gaining remarkable research attention,…
3D Localization with a Single Partially-Connected Receiving RIS: Positioning Error Analysis and Algorithmic Design
Jiguang He, Aymen Fakhreddine, Charles Vanwynsberghe +2
In this paper, we introduce the concept of partially-connected Receiving Reconfigurable Intelligent Surfaces (R-RISs), which refers to metasurfaces designed to efficiently sense el…
RIS-Aided Monostatic Sensing and Object Detection with Single and Double Bounce Multipath
Hyowon Kim, Alessio Fascista, Hui Chen +4
We propose a framework for monostatic sensing by a user equipment (UE), aided by a reconfigurable intelligent surface (RIS) in environments with single- and double-bounce signal pr…
Holographic MIMO Communications: Theoretical Foundations, Enabling Technologies, and Future Directions
Tierui Gong, Panagiotis Gavriilidis, Ran Ji +7
Future wireless systems are envisioned to create an endogenously holography-capable, intelligent, and programmable radio propagation environment, that will offer unprecedented capa…
Tri-Polarized Holographic MIMO Surface in Near-Field: Channel Modeling and Precoding Design
Li Wei, Chongwen Huang, George C. Alexandropoulos +6
This paper investigates the utilization of triple polarization (TP) for multi-user (MU) holographic multiple-input multi-output surface (HMIMOS) wireless communication systems, tar…
Integrated Sensing and Communications with Reconfigurable Intelligent Surfaces
Sundeep Prabhakar Chepuri, Nir Shlezinger, Fan Liu +3
Integrated sensing and communications (ISAC) are envisioned to be an integral part of future wireless networks, especially when operating at the millimeter-wave (mmWave) and terahe…
Compressed-Sensing-Based 3D Localization with Distributed Passive Reconfigurable Intelligent Surfaces
Jiguang He, Aymen Fakhreddine, Henk Wymeersch +1
In this paper, the programmable signal propagation paradigm, enabled by Reconfigurable Intelligent Surfaces (RISs), is exploited for high accuracy -Dimensional (3D) user localiz…
Joint Channel and Direction Estimation for Ground-to-UAV Communications Enabled by A Simultaneous Reflecting and Sensing RIS
Jiguang He, Aymen Fakhreddine, George C. Alexandropoulos
Hybrid Reconfigurable Intelligent Surfaces (HRISs), which are capable of simultaneous programmable reflections and sensing, are expected to play a significant role in future wirele…
Joint User Localization and Location Calibration of A Hybrid Reconfigurable Intelligent Surface
Reza Ghazalian, Hui Chen, George C. Alexandropoulos +3
The recent research in the emerging technology of reconfigurable intelligent surfaces (RISs) has identified its high potential for localization and sensing. However, to accurately…
Combining Relaying and Reflective Surfaces: Power Consumption and Energy Efficiency Analysis
Zaid Abdullah, George C. Alexandropoulos, Steven Kisseleff +2
Hybrid relaying networks (HRNs) combining both a relay and an intelligent reflective surface (IRS) can lead to enhanced rate performance compared to non-hybrid relaying schemes, wh…
Reconfiguring Wireless Environment via Intelligent Surfaces for 6G: Reflection, Modulation, and Security
Jindan Xu, Chau Yuen, Chongwen Huang +4
Reconfigurable intelligent surface (RIS) has been recognized as an essential enabling technique for the sixth-generation (6G) mobile communication network. Specifically, an RIS is…
Reconfigurable Intelligent Surfaces and Capacity Optimization: A Large System Analysis
Aris L. Moustakas, George C. Alexandropoulos, Mérouane Debbah
Reconfigurable Intelligent Surfaces (RISs), comprising large numbers of low-cost and almost passive metamaterials with tunable reflection properties, have been recently proposed as…
Distributed Sum-Rate Maximization of Cellular Communications with Multiple Reconfigurable Intelligent Surfaces
Konstantinos D. Katsanos, Paolo Di Lorenzo, George C. Alexandropoulos
The technology of Reconfigurable Intelligent Surfaces (RISs) has lately attracted considerable interest from both academia and industry as a low-cost solution for coverage extensio…
Reconfigurable Intelligent Computational Surfaces: When Wave Propagation Control Meets Computing
Bo Yang, Xuelin Cao, Jindan Xu +6
The envisioned sixth-generation (6G) of wireless networks will involve an intelligent integration of communications and computing, thereby meeting the urgent demands of diverse app…
Simultaneous Indoor and Outdoor 3D Localization with STAR-RIS-Assisted Millimeter Wave Systems
Jiguang He, Aymen Fakhreddine, George C. Alexandropoulos
Simultaneously transmitting (refracting) and reflecting reconfigurable intelligent surfaces (STAR-RISs) have been recently identified to improve the spectrum/energy efficiency and…
Time Reversal for 6G Spatiotemporal Focusing: Recent Experiments, Opportunities, and Challenges
George C. Alexandropoulos, Ali Mokh, Ramin Khayatzadeh +6
Late visions and trends for the future sixth Generation (6G) of wireless communications advocate, among other technologies, towards the deployment of network nodes with extreme num…
Channel Estimation with Hybrid Reconfigurable Intelligent Metasurfaces
Haiyang Zhang, Nir Shlezinger, George C Alexandropoulos +3
Reconfigurable Intelligent Surfaces (RISs) are envisioned to play a key role in future wireless communications, enabling programmable radio propagation environments. They are usual…
Simultaneous Multi-User MIMO Communications and Multi-Target Tracking with Full Duplex Radios
Md Atiqul Islam, George C. Alexandropoulos, Besma Smida
In this paper, we present an Integrated Sensing and Communications (ISAC) system enabled by in-band Full Duplex (FD) radios, where a massive Multiple-Input Multiple-Output (MIMO) b…
Full Duplex Massive MIMO Architectures: Recent Advances, Applications, and Future Directions
George C. Alexandropoulos, Md Atiqul Islam, Besma Smida
The increasingly demanding objectives for next generation wireless communications have spurred recent research activities on multi-antenna transceiver hardware architectures and re…
Pervasive Machine Learning for Smart Radio Environments Enabled by Reconfigurable Intelligent Surfaces
George C. Alexandropoulos, Kyriakos Stylianopoulos, Chongwen Huang +3
The emerging technology of Reconfigurable Intelligent Surfaces (RISs) is provisioned as an enabler of smart wireless environments, offering a highly scalable, low-cost, hardware-ef…
Near-Field Wideband Extremely Large-scale MIMO Transmission with Holographic Metasurface Antennas
Jie Xu, Li You, George C. Alexandropoulos +3
Extremely large-scale multiple-input multiple-output (XL-MIMO) is the development trend of future wireless communications. However, the extremely large-scale antenna array could br…
Leveraging RIS-Enabled Smart Signal Propagation for Solving Infeasible Localization Problems
Kamran Keykhosravi, Benoit Denis, George C. Alexandropoulos +4
Reconfigurable intelligent surfaces (RISs) have tremendous potential for both communication and localization. While communication benefits are now well-understood, the breakthrough…
Online RIS Configuration Learning for Arbitrary Large Numbers of -Bit Phase Resolution Elements
Kyriakos Stylianopoulos, George C. Alexandropoulos
Reinforcement Learning (RL) approaches are lately deployed for orchestrating wireless communications empowered by Reconfigurable Intelligent Surfaces (RISs), leveraging their onlin…