64 citations · 258 across the 43 of their papers we have counts for
50 papers
Reliable ORIS-assisted FSO Communications via HARQ
Georgios D. Chondrogiannis, Athanasios P. Chrysologou, Vasilis K. Papanikolaou +3
This paper studies a free-space optical (FSO) link assisted by an optical reconfigurable intelligent surface (ORIS) and enhanced by a hybrid automatic repeat request (HARQ) scheme.…
Physical-AI: From Channel Awareness to Environmental Intelligence in 6G Wireless Networks
Farooque Hassan Kumbhar, Kapal Dev, Sunder Ali Khowaja +3
Conventional wireless networks rely on instantaneous channel state information (CSI) and react to channel variations without explicitly modeling the physical environment, limiting…
On the Performance of THz Wireless Systems over - Channels with Beam Misalignment, Mobility and Hardware Impairments
Wamberto J. L. Queiroz, Higo T. P. Silva, Hugerles S. Silva +1
This paper investigates the performance of terahertz (THz) wireless systems over the - fading channels with beam misalignment, mobility and hardware impairments. Ne…
Spiking Neural Networks for Resource Allocation in UAV-Enabled Wireless Networks
Vasileios Kouvakis, Stylianos E. Trevlakis, Ioannis Arapakis +1
This work presents a new spiking neural network (SNN)-based approach for user equipment-base station (UE-BS) association in non-terrestrial networks (NTNs). With the introduction o…
Optical RIS-enabled Multiple Access Communications
Georgios D. Chondrogiannis, Athanasios P. Chrysologou, Alexandros-Apostolos A. Boulogeorgos +2
In this paper, we identify optical reconfigurable intelligent surfaces (ORISs) as key enablers of next-generation free-space optical (FSO) multiple access systems. By leveraging th…
Coalition Formation for Heterogeneous Federated Learning Enabled Channel Estimation in RIS-assisted Cell-free MIMO
Nan Qi, Haoxuan Liu, Theodoros A. Tsiftsis +4
Downlink channel estimation remains a significant bottleneck in reconfigurable intelligent surface-assisted cell-free multiple-input multiple-output communication systems. Conventi…
High-Fidelity Coherent-One-Way QKD Simulation Framework for 6G Networks: Bridging Theory and Reality
Aitor Brazaola-Vicario, Vasileios Kouvakis, Stylianos E. Trevlakis +4
Quantum key distribution (QKD) has been emerged as a promising solution for guaranteeing information-theoretic security. Inspired by this, a great amount of research effort has bee…
Hierarchical Blockchain Radio Access Networks: Architecture, Modelling, and Performance Assessment
Vasileios Kouvakis, Stylianos E. Trevlakis, Alexandros-Apostolos A. Boulogeorgos +4
Demands for secure, ubiquitous, and always-available connectivity have been identified as the pillar design parameters of the next generation radio access networks (RANs). Motivate…
Modeling blockage in high directional wireless. systems
Evangelos Koutsonas, Alexandros-Apostolos A. Boulogeorgos, Stylianos E. Trevlakis +2
While the wireless word moves towards higher frequency bands, new challenges arises, due to the inherent characteristics of the transmission links, such as high path and penetratio…
Optimal Operation of Active RIS-Aided Wireless Powered Communications in IoT Networks
Waqas Khalid, A. -A. A. Boulogeorgos, Trinh Van Chien +3
Wireless-powered communications (WPCs) are increasingly crucial for extending the lifespan of low-power Internet of Things (IoT) devices. Furthermore, reconfigurable intelligent su…
Active-RIS-Aided Covert Communications in NOMA-Inspired ISAC Wireless Systems
Miaomiao Zhu, Pengxu Chen, Liang Yang +3
Non-orthogonal multiple access (NOMA)-inspired integrated sensing and communication (ISAC) facilitates spectrum sharing for radar sensing and NOMA communications, whereas facing pr…
On the Reliability and Security of Ambient Backscatter Uplink NOMA Networks
Athanasios P. Chrysologou, Nestor D. Chatzidiamantis, Alexandros-Apostolos A. Boulogeorgos +1
A fundamental objective of the forthcoming sixth-generation wireless networks is to concurrently serve a vast array of devices many of which, such as Internet-of-Things (IoT) senso…
Outage Analysis for Active Reconfigurable Intelligent Surface-Enhanced Wireless Powered Communication Networks
Waqas Khalid, Heejung Yu, Alexandros-Apostolos A. Boulogeorgos
Wireless powered communication (WPC) involves the integration of energy harvesting and data transmission. This allows devices to communicate without constant battery replacements o…
NeuroRIS: Neuromorphic-Inspired Metasurfaces
Christos G. Tsinos, Alexandros-Apostolos A. Boulogeorgos, Theodoros A. Tsiftsis
Reconfigurable intelligent surfaces (RISs) operate similarly to electromagnetic (EM) mirrors and remarkably go beyond Snell law to generate an applicable EM environment allowing fo…
Holographic RIS Empowered THz Communications with Hardware Imperfections under Adverse Weather Conditions
Alexandros-Apostolos A. Boulogeorgos, Stylianos Trevlakis, Theodoros A. Tsiftsis
This paper focuses on providing a theoretical framework for the evaluation of the performance of holographic reconfigurable intelligent surface (HRIS) empowered terahertz (THz) wir…
Training Terahertz Wireless Systems to Battle I/Q Imbalance
Alexandros-Apostolos A. Boulogeorgos, Angeliki Alexiou
Due to the non-ideality of analog components, transceivers experience high levels of hardware imperfections, like in-phase and quadrature imbalance (IQI), which manifests itself as…
Can graph neural network-based detection mitigate the impact of hardware imperfections?
Lamprini Mitsiou, Stylianos Trevlakis, Argiris Tsiolas +3
Until recently, researchers used machine learning methods to compensate for hardware imperfections at the symbol level, indicating that optimum radio-frequency transceiver performa…
Power-Optimal HARQ Protocol for Reliable Free Space Optical Communication
Georgios D. Chondrogiannis, Nikos A. Mitsiou, Nestor D. Chatzidiamantis +2
This paper investigates the usage of hybrid automatic repeat request (HARQ) protocols for power-efficient and reliable communications over free space optical (FSO) links. By exploi…
On the Ergodic Secrecy Capacity of Reconfigurable Intelligent Surface Aided Wireless Systems Under Mixture Gamma Fading
Alexandros-Apostolos A. Boulogeorgos, Angeliki Alexiou
This paper presents a quantified assessment of the physical layer security capabilities of reconfigurable intelligent surface (RIS)-aided wireless systems under eavesdropping. Spec…
Channel modeling for in-body optical wireless communications
Stylianos E. Trevlakis, Alexandros-Apostolos A. Boulogeorgos, Nestor D. Chatzidiamantis +1
Next generation in-to-out-of body biomedical applications have adopted optical wireless communications (OWCs). However, by delving into the published literature, a gap is recognise…
Cascaded Composite Turbulence and Misalignment: Statistical Characterization and Applications to Reconfigurable Intelligent Surface-Empowered Wireless Systems
Alexandros-Apostolos A. Boulogeorgos, Nestor Chatzidiamantis, Harilaos G. Sandalidis +2
Reconfigurable intelligent surfaces (RISs) empowered high-frequency (HF) wireless systems are expected to become the supporting pillar for several reliability and data rate hungry…
Pathloss modeling for in-body optical wireless communications
Stylianos E. Trevlakis, Alexandros-Apostolos A. Boulogeorgos, Nestor D. Chatzidiamantis
Optical wireless communications (OWCs) have been recognized as a candidate enabler of next generation in-body nano-scale networks and implants. The development of an accurate chann…
Autonomous Reconfigurable Intelligent Surfaces Through Wireless Energy Harvesting
Konstantinos Ntontin, Alexandros-Apostolos A. Boulogeorgos, Emil Björnson +7
In this paper, we examine the potential for a reconfigurable intelligent surface (RIS) to be powered by energy harvested from information signals. This feature might be key to reap…
Pathloss modeling of reconfigurable intelligent surface assisted THz wireless systems
Alexandros-Apostolos A. Boulogeorgos, Angeliki Alexiou
This paper presents an analytical pathloss model for reconfigurable intelligent surface (RIS) assisted terahertz (THz) wireless systems. Specifically, the model accommodates both t…