no code implementations • 2 Dec 2023 • Giorgos Stratidakis, Sotiris Droulias, Angeliki Alexiou
Wireless communications are nowadays shifting to higher operation frequencies with the aim to meet the ever-increasing demand for bandwidth.
no code implementations • 2 Jun 2023 • Alexandros-Apostolos A. Boulogeorgos, Angeliki Alexiou
Two training approaches are implemented, namely: i) conventional that requires a considerable amount of data for training, and ii) a reinforcement learning based one, which demands a shorter dataset in comparison to the former.
no code implementations • 12 Dec 2022 • Evangelos N. Papasotiriou, Sotiris Droulias, Angeliki Alexiou
The terahertz (THz) frequency band has recently attracted considerable attention in wireless communications as potential candidate for providing the necessary high bandwidth for demanding applications.
no code implementations • 10 Dec 2022 • Alexandros-Apostolos A. Boulogeorgos, Angeliki Alexiou, Marco Di Renzo
Reconfigurable intelligent surface (RIS)-assisted unmanned areal vehicles (UAV) communications have been identified as a key enabler of a number of next-generation applications.
no code implementations • 17 Aug 2022 • Alexandros-Apostolos A. Boulogeorgos, Edwin Yaqub, Rachana Desai, Tachporn Sanguanpuak, Nikos Katzouris, Fotis Lazarakis, Angeliki Alexiou, Marco Di Renzo
In more detail, a fast and centralized joint user association, radio resource allocation, and blockage avoidance by means of a novel metaheuristic-machine learning framework is documented, that maximizes the THz networks performance, while minimizing the association latency by approximately three orders of magnitude.
no code implementations • 13 Feb 2022 • Alexandros-Apostolos A. Boulogeorgos, Nestor Chatzidiamantis, Harilaos G. Sandalidis, Angeliki Alexiou, Marco Di Renzo
In this paper, we introduce a theoretical framework for analyzing the performance of multi-reconfigurable intelligence surface (RIS) empowered terahertz (THz) wireless systems subject to turbulence and stochastic beam misalignment.
no code implementations • 28 Jan 2022 • Alexandros-Apostolos A. Boulogeorgos, Angeliki Alexiou, Marco Di Renzo
In this paper, we analyze the performance of a reconfigurable intelligent surface (RIS)-assisted unmanned aerial vehicle (UAV) wireless system that is affected by mixture-gamma small-scale fading, stochastic disorientation, and misalignment, as well as transceivers hardware imperfections.
no code implementations • 29 Jun 2021 • Alexandros-Apostolos A. Boulogeorgos, Nestor Chatzidiamantis, Harilaos G. Sandalidis, Angeliki Alexiou, Marco Di Renzo
Building upon the derived analytical expressions, we present novel closed-form formulas that quantify the joint impact of turbulence and misalignment on the outage performance for two scenarios of high interest namely cascaded multi-RIS-empowered free space optics (FSO) and terahertz (THz) wireless systems.
no code implementations • 17 Feb 2021 • Alexandros-Apostolos A. Boulogeorgos, Angeliki Alexiou
This paper presents an analytical pathloss model for reconfigurable intelligent surface (RIS) assisted terahertz (THz) wireless systems.
no code implementations • 19 Nov 2020 • Konstantinos Ntontin, Alexandros A. Boulogeorgos, Dimitrios Selimis, Fotis Lazarakis, Angeliki Alexiou, Symeon Chatzinotas
Subsequently, based on the model we derive the end-to-end expression of the received signal power and, furthermore, provide approximate closed-form expressions in the case that the RIS size is either much smaller or at least equal to the transmission beam footprint.
Information Theory Signal Processing Information Theory
no code implementations • 14 Aug 2020 • Evangelos N. Papasotiriou, Alexandros-Apostolos A. Boulogeorgos, Antigone Stratakou, Angeliki Alexiou
The system performance is evaluated in terms of pathgain and capacity considering the RIS design parameters, the TX/RX-RIS distance and the elevation angles from the center of the RIS to the transceivers.
no code implementations • 5 Aug 2020 • Alexandros-Apostolos A. Boulogeorgos, Angeliki Alexiou
This paper presents the analytic framework for evaluating the ergodic capacity (EC) of the reconfigurable intelligent surface (RIS) assisted systems.
no code implementations • 14 Jul 2020 • Alexandros-Apostolos A. Boulogeorgos, Angeliki Alexiou
This paper focuses on quantifying the outage performance of terahertz (THz) relaying systems.
no code implementations • 4 May 2020 • Giorgos Stratidakis, Georgia D. Ntouni, Alexandros-Apostolos A. Boulogeorgos, Dimitrios Kritharidis, Angeliki Alexiou
In this paper, a novel hierarchical beamtracking approach, which is suitable for terahertz (THz) wireless systems, is presented.