16 citations · 16 across the 41 of their papers we have counts for
46 papers
Structured PARAFAC Channel Estimation for Flexible Intelligent Metasurface Receivers
Xi Han, Junqiao Chen, Yuansheng Zhang +2
Flexible intelligent metasurfaces (FIMs) create geometric diversity through aperture morphing, but their configuration-dependent responses complicate uplink channel estimation. Thi…
Simultaneous Secure Communications and Sensing Privacy with Full Duplex MIMO Radios
Ioannis Gavras, George C. Alexandropoulos
This paper proposes a Full Duplex (FD) framework for safeguarding Integrated Sensing and Communications (ISAC) against a passive multi-antenna Eavesdropper (Eve). The adversary is…
Over-The-Air Extreme Learning Machines with Nonlinear Stacked Intelligent Metasurfaces
Kyriakos Stylianopoulos, Mattia Fabiani, Giulia Torcolacci +2
The recently envisioned goal-oriented communications paradigm requires machine learning inference to be performed directly on wirelessly transferred data. This paper presents an eX…
-ACT: End-to-End Verifiable Agentic Intent Control for Open 6G RAN
Sunder Ali Khowaja, Kapal Dev, George C. Alexandropoulos
With the progression in open and disaggregated 6G radio access networks, it is expected that the system will be able to host multi-vendors. In order to host multi-vendors, it is es…
Energy Efficient Multi-User Beamforming and 3D Position Optimization for SIM-Assisted UAVs
Chandan Kumar Sheemar, Giovanni Iacovelli, Sourabh Solanki +3
This paper studies energy-efficient downlink multi-user transmissions with unmanned aerial vehicle (UAV) communication systems equipped with stacked intelligent metasurfaces (SIM),…
TenSIM: Tensor-Based Channel Estimation for MIMO Systems with Stacked Intelligent Metasurfaces
André L. F. de Almeida, George C. Alexandropoulos
Stacked intelligent metasurfaces (SIMs) are emerging as a promising architecture for sixth-generation (6G) and beyond wireless systems, enabling richer electromagnetic-wave manipul…
Task-Oriented Sensing and Covert Transmissions for Collaborative Multi-AUV Systems
Xueyao Zhang, Chenyang Yan, Bo Yang +7
In underwater covert cooperative missions, autonomous underwater vehicles (AUVs) often cannot rely on active sonar to continuously obtain complete information, since active sensing…
RIS Beamforming under Element-Level Variations: Statistical Characterization and Robust Design
Dimitris Kompostiotis, Dimitris Vordonis, Vassilis Paliouras +1
In this paper, a novel analytical framework to characterize the impact of element-level variations on the radiation characteristics of reconfigurable intelligent surfaces (RISs) is…
Learning to Distributedly Estimate under Partially Known Dynamics: A Covariance-Agnostic Neural Kalman Consensus Filter
George Stamatelis, Kyriakos Stylianopoulos, George C. Alexandropoulos
Online latent state estimation constitutes a fundamental challenge within the artificial intelligence field, serving as a foundational tool for diverse applications, including sequ…
Robust Beamforming for Cell-Free Systems with Parallel-Plate-Waveguided Dynamic Metasurfaces
Konstantinos D. Katsanos, Panagiotis Gavriilidis, George C. Alexandropoulos
Dynamic Metasurface Antennas (DMAs) constitute a promising solution for extremely large antenna arrays, requiring lower power consumption and reduced hardware cost as compared to c…
A Near-Field Compatible Model for 2D Waveguide-Fed Metasurfaces
Panagiotis Gavriilidis, George C. Alexandropoulos
This paper presents a novel physically consistent analytical model for two-dimensional (2D) waveguide-fed metasurface antennas that is based on the discrete dipole approximation. T…
Near-Field Beam Focusing Characterization for 2D Waveguide-Fed Metasurface Antennas
Panagiotis Gavriilidis, George C. Alexandropoulos
Two-dimensional (2D) waveguide-fed metasurfaces enable scalable antenna apertures through guided wave excitation of distributed radiating elements. However, the resulting non-unifo…
2D Waveguide-Fed Metasurfaces: Physically Consistent Modeling, Validation, and Optimization
Panagiotis Gavriilidis, George C. Alexandropoulos
Antenna array architectures based on programmable metasurfaces are emerging as a promising solution for scalable implementations of the eXtremely Large Multiple-Input Multiple-Outp…
Low-Complexity Learning-Based Beamforming for Ultra-Massive MIMO THz Communications
Sourabh Solanki, Abuzar Babikir Mohammad Adam, Chandan Kumar Sheemar +4
Terahertz (THz) communications have emerged as a key technology for escalating data rates in future generation wireless networks. However, severe propagation losses at THz frequenc…
Wideband Sensing with Dynamic Metasurface Antennas under Realistic Phase Response Modeling
Ioannis Gavras, George C. Alexandropoulos
This paper investigates the impact of practical features of the emerging antenna array technology of Dynamic Metasurface Antennas (DMAs) when used for wideband sensing. By adopting…
Multi-User Symbol Detection with XL Reception: Dynamic Metasurface Antennas with Low Resolution ADCs
Rahul K. Pal, Soumya P. Dash, Barathram Ramkumar +1
Dynamic Metasurface Antennas (DMAs) have been recently proposed as a cost- and energy-efficient front-end solution for eXtremely Large (XL) antenna array systems, supporting scalab…
Symbol Error Analysis for Fluid Antenna Systems with One- and Two-Dimensional Modulation Schemes
Soumya P. Dash, George C. Alexandropoulos
This paper considers a Fluid Antenna (FA) system comprising a single-antenna transmitter that communicates with a receiver equipped with an FA array with ports. The transmitter…
Toward Integrated Sensing, Communications, and Edge Intelligence Networks
Mattia Merluzzi, Miltiadis C. Filippou, Paolo Di Lorenzo +1
Wireless systems are expanding their purposes, from merely connecting humans and things to connecting intelligence and opportunistically sensing of the environment through radio-fr…
STAR Beyond Diagonal RISs with Amplification: Modeling and Optimization
Chandan Kumar Sheemar, Giovanni Iacovelli, Wali Ullah Khan +3
This paper develops a physically consistent signal model with hardware constraints for a simultaneous transmitting and reflecting beyond-diagonal RIS (STAR BD-RIS) endowed with per…
A Survey on Stacked Intelligent Metasurfaces: Fundamentals, Recent Advances, and Challenges
Chandan Kumar Sheemar, Wali Ullah Khan, Sourabh Solanki +2
Reconfigurable intelligent surfaces (RISs) enable programmable control of wireless propagation. Beyond environmental deployments, integrating metasurfaces at the antenna front end…
Secret Key Rate Analysis of RIS-Assisted THz MIMO CV-QKD Systems under Access-Constrained Eavesdropping
Sushil Kumar, Soumya P. Dash, George C. Alexandropoulos
A reconfigurable intelligent surface (RIS)-assisted multiple-input multiple-output (MIMO) continuous-variable quantum key distribution (CV-QKD) system operating at terahertz (THz)…
Metasurfaces-Integrated Wireless Neural Networks for Lightweight Over-The-Air Edge Inference
Kyriakos Stylianopoulos, Mario Edoardo Pandolfo, Paolo Di Lorenzo +1
The upcoming sixth Generation (6G) of wireless networks envisions ultra-low latency and energy efficient Edge Inference (EI) for diverse Internet of Things (IoT) applications. Howe…
RIS-Enabled Spoofing Against Adversary Sensing: CRB-Maximizing Design and Decoying Analysis
Ioannis Gavras, Giuseppe Thadeu Freitas de Abreu, George C. Alexandropoulos
This paper studies the capability of a Reconfigurable Intelligent Surface (RIS), when transparently covering a User Equipment (UE), to deceive an adversary monostatic radar system.…
Over-The-Air Extreme Learning Machines with XL Reception via Nonlinear Cascaded Metasurfaces
Kyriakos Stylianopoulos, Mattia Fabiani, Giulia Torcolacci +2
The recently envisioned goal-oriented communications paradigm calls for the application of inference on wirelessly transferred data via Machine Learning (ML) tools. An emerging res…