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George C. Alexandropoulos

13 accepted papers

2024

Joint Near-Field Target Tracking and Communications with full Duplex Holographic MIMO

ICASSP 2024accepted

In this paper, we present a simultaneous target tracking and multi-user communications system realized by a full duplex holographic Multiple-Input Multiple-Output (MIMO) node equipped with Dynamic Metasurface Antennas (DMAs) at both its communication ends. Focusing on the near-field regime, we exten…

Cited by 0SourceScholar
2024

Leaky Waveguide Antennas for Downlink Wideband THz Communications

ICASSP 2024accepted

THz communications are expected to play a profound role in future wireless systems. The current trend of the extremely massive multiple-input multiple-output (MIMO) antenna architectures tends to be costly and power inefficient when implementing wideband THz communications. An emerging THz antenna t…

Cited by 6SourceScholar
2024

Metasurface-Based Receivers with 1-bit ADCS for multi-user Uplink Communications

ICASSP 2024accepted

The massive Multiple-Input Multiple-Output (mMIMO) concept has been recently moving forward to extreme scales to address the envisioned requirements of next generation networks. However, the extension of conventional architectures will result in significant cost and power consumption. To this end, m…

Cited by 0SourceScholar
2024

Near-Field Localization with 1-bit Quantized Hybrid A/D Reception

ICASSP 2024accepted

In this paper, we consider a hybrid Analog and Digital (A/D) receiver architecture with an extremely large Dynamic Metasurface Antenna (DMA) and an 1-bit resolution Analog-to-Digital Converter (ADC) at each of its reception radio-frequency chains, and present a localization approach for User Equipme…

Cited by 0SourceScholar
2023

Compressed-Sensing-Based 3D Localization with Distributed Passive Reconfigurable Intelligent Surfaces

ICASSP 2023accepted

In this paper, the programmable signal propagation paradigm, enabled by Reconfigurable Intelligent Surfaces (RISs), is exploited for high accuracy 3-Dimensional (3D) user localization with a single multi-antenna base station. Capitalizing on the tunable reflection capability of passive RISs, we pres…

Cited by 0SourceScholar
2023

Joint Channel and Direction Estimation for Ground-to-UAV Communications Enabled by a Simultaneous Reflecting and Sensing RIS

ICASSP 2023accepted

Hybrid Reconfigurable Intelligent Surfaces (HRISs), which are capable of simultaneous programmable reflections and sensing, are expected to play a significant role in future wireless networks, enabling various Integrated Sensing and Communication (ISAC) applications. In this paper, we focus on HRIS-…

Cited by 0SourceScholar
2023

Lyapunov-Driven Deep Reinforcement Learning for Edge Inference Empowered by Reconfigurable Intelligent Surfaces

ICASSP 2023accepted

In this paper, we propose a novel algorithm for energy-efficient, low-latency, accurate inference at the wireless edge, in the context of 6G networks endowed with reconfigurable intelligent surfaces (RISs). We consider a scenario where new data are continuously generated/collected by a set of device…

Cited by 0SourceScholar
2023

RIS Reflection and Placement Optimisation for Underlay D2D Communications in Cognitive Cellular Networks

ICASSP 2023accepted

Reconfigurable intelligent surface (RIS) is considered a promising technology in sixth-generation (6G) networks due to its ability to configure the phase of signals using low-cost reflecting elements. An RIS-aided device-to-device (D2D) communication system operating in underlay mode is considered i…

Cited by 0SourceScholar
2022

ADMM-DAD Net: A Deep Unfolding Network for Analysis Compressed Sensing

ICASSP 2022accepted

In this paper, we propose a new deep unfolding neural network based on the ADMM algorithm for analysis Compressed Sensing. The proposed network jointly learns a redundant analysis operator for sparsification and reconstructs the signal of interest. We compare our proposed network with a state-of-the…

Cited by 0SourceScholar
2022

Deep-Learning-Assisted Configuration of Reconfigurable Intelligent Surfaces in Dynamic Rich-Scattering Environments

ICASSP 2022accepted

The integration of Reconfigurable Intelligent Surfaces (RISs) into wireless environments endows channels with programmability, and is expected to play a key role in future communication standards. To date, most RIS-related efforts focus on quasi-free-space, where wireless channels are typically mode…

Cited by 0SourceScholar
2020

A Hardware Architecture For Reconfigurable Intelligent Surfaces with Minimal Active Elements for Explicit Channel Estimation

ICASSP 2020accepted

Intelligent surfaces comprising of cost effective, nearly passive, and reconfigurable unit elements are lately gaining increasing interest due to their potential in enabling fully programmable wireless environments. They are envisioned to offer environmental intelligence for diverse communication ob…

Cited by 0SourceScholar
2020

Wideband Channel Tracking for Millimeter Wave Massive Mimo Systems with Hybrid Beamforming Reception

ICASSP 2020accepted

Millimeter Wave (mmWave) massive Multiple Input Multiple Output (MIMO) channel tracking is a challenging task with Hybrid analog and digital BeamForming (HBF) reception architectures. The wireless channel can only be spatially sampled with directive analog beams, which results in lengthy training pe…

Cited by 0SourceScholar
2019

Indoor Time Reversal Wireless Communication: Experimental Results for Localization and Signal Coverage

ICASSP 2019accepted

Communication based on Time Reversal (TR) exploits rich multipath radio propagation for high resolution spatiotemporal focusing. It refers to the process of transmitting a received signal in a time reversed order, profiting from channel's spatial reciprocity. Recent theoretical studies have shown th…

Cited by 15SourceScholar