725 citations · 3k across the 227 of their papers we have counts for
44 papers · 1 filter
RIS-Assisted MIMO CV-QKD at THz Frequencies: Channel Estimation and SKR Analysis
Sushil Kumar, Soumya P. Dash, Debasish Ghose +1
In this paper, a multiple-input multiple-output (MIMO) wireless system incorporating a reconfigurable intelligent surface (RIS) to efficiently operate at terahertz (THz) frequencie…
Optimal Multi-Level ASK Modulations for RIS-Assisted Communications with Energy-Based Noncoherent Reception
Sambit Mishra, Soumya P. Dash, George C. Alexandropoulos
This paper investigates the performance of one- and two-sided amplitude shift keying (ASK) modulations in noncoherent single-input single-output (SISO) wireless communication syste…
Characterization of Indoor RIS-Assisted Channels at 304 GHz: Experimental Measurements, Challenges, and Future Directions
George C. Alexandropoulos, Bo Kum Jung, Panagiotis Gavriilidis +7
Reconfigurable Intelligent Surfaces (RISs) are expected to play a pivotal role in future indoor ultra high data rate wireless communications as well as highly accurate three-dimens…
Holographic MIMO for Next Generation Non-Terrestrial Networks: Motivation, Opportunities, and Challenges
Giovanni Iacovelli, Chandan Kumar Sheemar, Wali Ullah Khan +4
In this article, we propose the integration of the Holographic Multiple Input Multiple Output (HMIMO) as a transformative solution for next generation Non-Terrestrial Networks (NTN…
Evaluation of RIS-Enabled B5G/6G Indoor Positioning and Mapping using Ray Tracing Models
Dimitris Kompostiotis, Dimitris Vordonis, Vassilis Paliouras +2
A Reconfigurable Intelligent Surface (RIS) can significantly enhance network positioning and mapping, acting as an additional anchor point in the reference system and improving sig…
Circuit-Compliant Optimization of Dynamic Metasurface Antennas for Near-Field Localization
Ioannis Gavras, George C. Alexandropoulos
This paper presents an optimization framework for near-field localization with Dynamic Metasurface Antenna (DMA) receivers. This metasurface technology offers enhanced angular and…
Simultaneous Communications and Sensing with Hybrid Reconfigurable Intelligent Surfaces
Ioannis Gavras, George C. Alexandropoulos
Hybrid Reconfigurable Intelligent Surfaces (HRISs) constitute a new paradigm of truly smart metasurfaces with the additional features of signal reception and processing, which have…
On the Detection of Non-Cooperative RISs: Scan B-Testing via Deep Support Vector Data Description
George Stamatelis, Panagiotis Gavriilidis, Aymen Fakhreddine +1
In this paper, we study the problem of promptly detecting the presence of non-cooperative activity from one or more Reconfigurable Intelligent Surfaces (RISs) with unknown characte…
MIMO MAC Empowered by Reconfigurable Intelligent Surfaces: Capacity Region and Large System Analysis
Aris L. Moustakas, George C. Alexandropoulos
Smart wireless environments enabled by multiple distributed Reconfigurable Intelligent Surfaces (RISs) have recently attracted significant research interest as a wireless connectiv…
In-Band Full-Duplex MIMO Systems for Simultaneous Communications and Sensing: Challenges, Methods, and Future Perspectives
Besma Smida, George C. Alexandropoulos, Taneli Riihonen +1
In-band Full-Duplex (FD) Multiple-Input Multiple-Output (MIMO) systems offer a significant opportunity for Integrated Sensing and Communications (ISAC) due to their capability to r…
Optimal One- and Two-Sided Multi-level ASK Modulation or RIS-Assisted Noncoherent Communication Systems
Srijika Mukhopadhyay, Badri Ramanjaneya Reddy, Soumya P. Dash +2
In this paper, we analyze the performance of one- and two-sided amplitude shift keying (ASK) modulations in single-input single-output wireless communication aided by a reconfigura…
Computation Pre-Offloading for MEC-Enabled Vehicular Networks via Trajectory Prediction
Ting Zhang, Bo Yang, Zhiwen Yu +4
Task offloading is of paramount importance to efficiently orchestrate vehicular wireless networks, necessitating the availability of information regarding the current network statu…
Near-Field Multipath MIMO Channel Model for Imperfect Surface Reflection
Mohamadreza Delbari, George C. Alexandropoulos, Robert Schober +2
Near-field (NF) communications is receiving renewed attention in the context of passive reconfigurable intelligent surfaces (RISs) due to their potentially extremely large dimensio…
The Interference Broadcast Channel with Reconfigurable Intelligent Surfaces: A Cooperative Sum-Rate Maximization Approach
Konstantinos D. Katsanos, Paolo Di Lorenzo, George C. Alexandropoulos
This paper studies the interference broadcast channel comprising multiple multi-antenna Base Stations (BSs), each controlling a beyond diagonal Reconfigurable Intelligent Surface (…
Multi-Branch Attention Convolutional Neural Network for Online RIS Configuration with Discrete Responses: A Neuroevolution Approach
George Stamatelis, Kyriakos Stylianopoulos, George C. Alexandropoulos
In this paper, we consider the problem of jointly controlling the configuration of a Reconfigurable Intelligent Surface (RIS) with unit elements of discrete responses and a codeboo…
Fast Network Recovery from Large-Scale Disasters: A Resilient and Self-Organizing RAN Framework
M. Yaser Yagan, Sefa Kayraklik, Samed Kesir +8
Extreme natural phenomena are occurring more frequently everyday in the world, challenging, among others, the infrastructure of communication networks. For instance, the devastatin…
Near-Field Localization with Antenna Arrays in the Presence of Direction-Dependent Mutual Coupling
Zohreh Ebadi, Amir Masoud Molaei, George C. Alexandropoulos +4
Localizing near-field sources considering practical arrays is a recent challenging topic for next generation wireless communication systems. Practical antenna array apertures with…
Multi-User MISO with Stacked Intelligent Metasurfaces: A DRL-Based Sum-Rate Optimization Approach
Hao Liu, Jiancheng An, George C. Alexandropoulos +3
Stacked intelligent metasurfaces (SIMs) represent a novel signal processing paradigm that enables over-the-air processing of electromagnetic waves at the speed of light. Their mult…
Metasurface Energy Harvesters: State-of-the-Art Designs and Their Potential for Energy Sustainable Reconfigurable Intelligent Surfaces
Alireza Ghaneizadeh, Panagiotis Gavriilidis, Mojtaba Joodaki +1
Metasurface Energy Harvesters (MEHs) have emerged as a prominent enabler of highly efficient Radio Frequency (RF) energy harvesters. This survey delves into the fundamentals of the…
Asymptotically Optimal Closed-Form Phase Configuration of -bit RISs via Sign Alignment
Kyriakos Stylianopoulos, Panagiotis Gavriilidis, George C. Alexandropoulos
While Reconfigurable Intelligent Surfaces (RISs) constitute one of the most prominent enablers for the upcoming sixth Generation (6G) of wireless networks, the design of efficient…
Simultaneous Near-Field THz Communications and Sensing with Full Duplex Metasurface Transceivers
Ioannis Gavras, George C. Alexandropoulos
In this paper, a Full Duplex (FD) eXtremely Large (XL) Multiple-Input Multiple-Output (MIMO) node equipped with reconfigurable metasurface antennas at its transmission and receptio…
Reconfigurable Intelligent Computational Surfaces for MEC-Assisted Autonomous Driving Networks: Design Optimization and Analysis
Xueyao Zhang, Bo Yang, Zhiwen Yu +5
This paper investigates autonomous driving safety improvement via task offloading from cellular vehicles (CVs) to a multi-access edge computing (MEC) server using vehicle-to-infras…
Sustainable Wireless Networks via Reconfigurable Intelligent Surfaces (RISs): Overview of the ETSI ISG RIS
Ruiqi Liu, Shuang Zheng, Qingqing Wu +5
Reconfigurable Intelligent Surfaces (RISs) are a novel form of ultra-low power devices that are capable to increase the communication data rates as well as the cell coverage in a c…
Near-Field Beam Tracking with Extremely Large Dynamic Metasurface Antennas
Panagiotis Gavriilidis, George C. Alexandropoulos
The interplay between large antenna apertures and high frequencies in future generations of wireless networks will give rise to near-field communications. In this paper, we focus o…