Search Results for author: George K. Karagiannidis

Found 36 papers, 3 papers with code

Secrecy Rate Maximization with Artificial Noise for Pinching-Antenna Systems

no code implementations14 Apr 2025 Pigi P. Papanikolaou, Dimitrios Bozanis, Sotiris A. Tegos, Panagiotis D. Diamantoulakis, George K. Karagiannidis

Security is emerging as a critical performance metric for next-generation wireless networks, but conventional multiple-input-multiple-output (MIMO) systems often suffer from severe path loss and are vulnerable to nearby eavesdroppers due to their fixed-antenna configurations.

Redefining Information Freshness: AoGI for Generative AI in 6G Networks

no code implementations6 Apr 2025 Yuquan Xiao, Qinghe Du, Wenchi Cheng, George K. Karagiannidis, Arumugam Nallanathan, Mohsen Guizani

Generative Artificial Intelligence (GenAI) is playing an increasingly important role in enriching and facilitating human life by generating various useful information, of which real-time GenAI is a significant part and has great potential in applications such as real-time robot control, automated driving, augmented reality, etc.

Cross-Band Modulation Design for Hybrid RF-Optical Systems

no code implementations21 Mar 2025 Thrassos K. Oikonomou, Sotiris A. Tegos, Panagiotis D. Diamantoulakis, George K. Karagiannidis

We present a novel cross-band modulation framework that combines 3D modulation in the RF domain with intensity modulation and direct detection in the optical domain, the first such integration to enhance communication reliability.

Stochastic Geometry for Modeling and Analysis of Sensing and Communications: A Survey

no code implementations12 Mar 2025 Harris K. Armeniakos, Petros S. Bithas, Sotiris A. Tegos, Athanasios G. Kanatas, George K. Karagiannidis

Stochastic geometry is the study and analysis of random spatial patterns, and as such, stochastic geometry tools have been considered for the performance evaluation of wireless networks with different types of nodes.

ISAC Point Processes

Latency-Aware Resource Allocation for Integrated Communications, Computation, and Sensing in Cell-Free mMIMO Systems

no code implementations24 Feb 2025 Qihao Peng, Qu Luo, Zheng Chu, Zihuai Lin, Maged Elkashlan, Pei Xiao, George K. Karagiannidis, Christos Masouros

In this paper, we investigate a cell-free massive multiple-input and multiple-output (MIMO)-enabled integration communication, computation, and sensing (ICCS) system, aiming to minimize the maximum computation latency to guarantee the stringent sensing requirements.

ISAC Scheduling

AFDM-Enabled Integrated Sensing and Communication: Theoretical Framework and Pilot Design

no code implementations20 Feb 2025 Fan Zhang, Zhaocheng Wang, Tianqi Mao, Tianyu Jiao, Yinxiao Zhuo, Miaowen Wen, Wei Xiang, Sheng Chen, George K. Karagiannidis

However, the unprecedented characteristics of 6G, especially the doubly dispersive channel, make classical ISAC waveforms rather challenging to guarantee a desirable performance level.

Integrated sensing and communication ISAC

Split Learning in Computer Vision for Semantic Segmentation Delay Minimization

no code implementations18 Dec 2024 Nikos G. Evgenidis, Nikos A. Mitsiou, Sotiris A. Tegos, Panagiotis D. Diamantoulakis, George K. Karagiannidis

In this paper, we propose a novel approach to minimize the inference delay in semantic segmentation using split learning (SL), tailored to the needs of real-time computer vision (CV) applications for resource-constrained devices.

Autonomous Vehicles Semantic Segmentation

Fluid Antenna Systems Enabling 6G:Principles, Applications, and Research Directions

no code implementations5 Dec 2024 Tuo Wu, Kangda Zhi, Junteng Yao, Xiazhi Lai, Jianchao Zheng, Hong Niu, Maged Elkashlan, Kai-Kit Wong, Chan-Byoung Chae, Zhiguo Ding, George K. Karagiannidis, Merouane Debbah, Chau Yuen

Fluid antenna system (FAS) as a new version of reconfigurable antenna technologies promoting shape and position flexibility, has emerged as an exciting and possibly transformative technology for wireless communications systems.

Position

FAS-Driven Spectrum Sensing for Cognitive Radio Networks

no code implementations13 Nov 2024 Junteng Yao, Ming Jin, Tuo Wu, Maged Elkashlan, Chau Yuen, Kai-Kit Wong, George K. Karagiannidis, Hyundong Shin

Cognitive radio (CR) networks face significant challenges in spectrum sensing, especially under spectrum scarcity.

Hybrid Semantic-Shannon Communications

no code implementations2 Oct 2024 Nikos G. Evgenidis, Nikos A. Mitsiou, Sotiris A. Tegos, Panagiotis D. Diamantoulakis, Panagiotis Sarigiannidis, Ioannis Krikidis, George K. Karagiannidis

Semantic communications are considered a promising beyond-Shannon/bit paradigm to reduce network traffic and increase reliability, thus making wireless networks more energy efficient, robust, and sustainable.

Transmit Beamforming Design for ISAC with Stacked Intelligent Metasurfaces

no code implementations5 Sep 2024 Shunyu Li, Fan Zhang, Tianqi Mao, Rui Na, Zhaocheng Wang, George K. Karagiannidis

This paper proposes a transmit beamforming strategy for the integrated sensing and communication (ISAC) systems enabled by the novel stacked intelligent metasurface (SIM) architecture, where the base station (BS) simultaneously performs downlink communication and radar target detection via different beams.

Integrated sensing and communication ISAC

Age of Trust (AoT): A Continuous Verification Framework for Wireless Networks

no code implementations4 Jun 2024 Yuquan Xiao, Qinghe Du, Wenchi Cheng, Panagiotis D. Diamantoulakis, George K. Karagiannidis

We then investigate how to find a compromise between average AoT and wireless transmission efficiency with limited resources.

Philosophy Q-Learning

Statistical Age of Information: A Risk-Aware Metric and Its Applications in Status Updates

no code implementations4 Jun 2024 Yuquan Xiao, Qinghe Du, George K. Karagiannidis

Motivated by this concern, and following the spirit of entropic value-at-risk (EVaR) in the field of risk analysis, in this paper we present a concept, termed Statistical AoI, for providing a unified framework to guarantee various requirements of risk-sensitive status-update services with the demand on the violation probability of the peak age.

Waveform Design for Over-the-Air Computing

no code implementations31 May 2024 Nikos G. Evgenidis, Nikos A. Mitsiou, Sotiris A. Tegos, Panagiotis D. Diamantoulakis, Panagiotis Sarigiannidis, Ioannis T. Rekanos, George K. Karagiannidis

To this end, we examine the theoretical mean squared error (MSE) for OTA transmission under time sampling error and ISI, while also exploring methods for minimizing the MSE in the OTA transmission.

Deep Joint Semantic Coding and Beamforming for Near-Space Airship-Borne Massive MIMO Network

no code implementations30 May 2024 Minghui Wu, Zhen Gao, Zhaocheng Wang, Dusit Niyato, George K. Karagiannidis, Sheng Chen

Specifically, we propose a deep joint semantic coding and beamforming (JSCBF) scheme for airship-based massive MIMO image transmission network in space, in which semantics from both source and channel are fused to jointly design the semantic coding and physical layer beamforming.

Image Reconstruction Semantic Communication

StatAvg: Mitigating Data Heterogeneity in Federated Learning for Intrusion Detection Systems

no code implementations20 May 2024 Pavlos S. Bouzinis, Panagiotis Radoglou-Grammatikis, Ioannis Makris, Thomas Lagkas, Vasileios Argyriou, Georgios Th. Papadopoulos, Panagiotis Sarigiannidis, George K. Karagiannidis

Federated learning (FL) is a decentralized learning technique that enables participating devices to collaboratively build a shared Machine Leaning (ML) or Deep Learning (DL) model without revealing their raw data to a third party.

Federated Learning Intrusion Detection +1

On the Intersection of Signal Processing and Machine Learning: A Use Case-Driven Analysis Approach

1 code implementation25 Mar 2024 Sulaiman Aburakhia, Abdallah Shami, George K. Karagiannidis

Despite many attempts in the existing literature to bridge this gap, most are limited to specific applications and focus mainly on feature extraction, often assuming extensive prior knowledge in signal processing.

EEG

Multiple Access in the Era of Distributed Computing and Edge Intelligence

no code implementations26 Feb 2024 Nikos G. Evgenidis, Nikos A. Mitsiou, Vasiliki I. Koutsioumpa, Sotiris A. Tegos, Panagiotis D. Diamantoulakis, George K. Karagiannidis

This paper focuses on the latest research and innovations in fundamental next-generation multiple access (NGMA) techniques and the coexistence with other key technologies for the sixth generation (6G) of wireless networks.

Distributed Computing Edge-computing +1

Learning to Optimize Resource Assignment for Task Offloading in Mobile Edge Computing

no code implementations15 Mar 2022 Yurong Qian, Jindan Xu, Shuhan Zhu, Wei Xu, Lisheng Fan, George K. Karagiannidis

In this paper, we consider a multiuser mobile edge computing (MEC) system, where a mixed-integer offloading strategy is used to assist the resource assignment for task offloading.

Edge-computing

Wireless Quantized Federated Learning: A Joint Computation and Communication Design

no code implementations11 Mar 2022 Pavlos S. Bouzinis, Panagiotis D. Diamantoulakis, George K. Karagiannidis

The impact of the quantization error on the convergence time is evaluated and the trade-off among model accuracy and timely execution is revealed.

Federated Learning Quantization

Optimization of Grant-Free NOMA with Multiple Configured-Grants for mURLLC

no code implementations17 Nov 2021 Yan Liu, Yansha Deng, Maged Elkashlan, Arumugam Nallanathan, George K. Karagiannidis

To support these requirements, the third generation partnership project (3GPP) has introduced enhanced grant-free (GF) transmission in the uplink (UL), with multiple active configured-grants (CGs) for URLLC UEs.

Channel modeling for in-body optical wireless communications

no code implementations3 Nov 2021 Stylianos E. Trevlakis, Alexandros-Apostolos A. Boulogeorgos, Nestor D. Chatzidiamantis, George K. Karagiannidis

Moreover, we formulate a model for the calculation of the absorption coefficient of any generic biological tissue.

Waveform Design for Joint Sensing and Communications in Millimeter-Wave and Low Terahertz Bands

no code implementations3 Jun 2021 Tianqi Mao, Jiaxuan Chen, Qi Wang, Chong Han, Zhaocheng Wang, George K. Karagiannidis

Finally, a data-embedded MS-QP (DE-MS-QP) waveform is constructed through time-domain extension of the MS-QP sequence, generating null frequency points on each subband for data transmission.

Wireless Federated Learning (WFL) for 6G Networks -- Part II: The Compute-then-Transmit NOMA Paradigm

no code implementations24 Apr 2021 Pavlos S. Bouzinis, Panagiotis D. Diamantoulakis, George K. Karagiannidis

As it has been discussed in the first part of this work, the utilization of advanced multiple access protocols and the joint optimization of the communication and computing resources can facilitate the reduction of delay for wireless federated learning (WFL), which is of paramount importance for the efficient integration of WFL in the sixth generation of wireless networks (6G).

Federated Learning

On the Distribution of the Sum of Double-Nakagami-m Random Vectors and Application in Randomly Reconfigurable Surfaces

no code implementations10 Feb 2021 Sotiris A. Tegos, Dimitrios Tyrovolas, Panagiotis D. Diamantoulakis, George K. Karagiannidis

To facilitate the performance analysis of a RRS-assisted system, first, we present novel closed-form expressions for the probability density function, the cumulative distribution function, the moments, and the characteristic function of the distribution of the sum of double-Nakagami-m random vectors, whose amplitudes follow the double-Nakagami-m distribution, i. e., the distribution of the product of two Nakagami-m random variables, and phases follow the circular uniform distribution.

Information Theory Signal Processing Information Theory Applications

Learning based signal detection for MIMO systems with unknown noise statistics

1 code implementation21 Jan 2021 Ke He, Le He, Lisheng Fan, Yansha Deng, George K. Karagiannidis, Arumugam Nallanathan

Existing detection methods have mainly focused on specific noise models, which are not robust enough with unknown noise statistics.

Towards Optimally Efficient Search with Deep Learning for Large-Scale MIMO Systems

1 code implementation7 Jan 2021 Le He, Ke He, Lisheng Fan, Xianfu Lei, Arumugam Nallanathan, George K. Karagiannidis

This indicates that the proposed algorithm reaches almost the optimal efficiency in practical scenarios, and thereby it is applicable for large-scale systems.

Non-Orthogonal Multiple Access (NOMA) With Multiple Intelligent Reflecting Surfaces

no code implementations31 Oct 2020 Yanyu Cheng, Kwok Hung Li, Yuanwei Liu, Kah Chan Teh, George K. Karagiannidis

More importantly, simulation results reveal that a 3-bit resolution for discrete phase shifts is sufficient to achieve near-optimal outage performance.

Diversity

Optimal Resource Allocation for Delay Minimization in NOMA-MEC Networks

no code implementations11 Sep 2020 Fang Fang, Yanqing Xu, Zhiguo Ding, Chao Shen, Mugen Peng, George K. Karagiannidis

We adopt the partial offloading policy, in which each user can partition its computation task into offloading and locally computing parts.

Edge-computing

AnciNet: An Efficient Deep Learning Approach for Feedback Compression of Estimated CSI in Massive MIMO Systems

no code implementations17 Aug 2020 Yuyao Sun, Wei Xu, Lisheng Fan, Geoffrey Ye Li, George K. Karagiannidis

Accurate channel state information (CSI) feedback plays a vital role in improving the performance gain of massive multiple-input multiple-output (m-MIMO) systems, where the dilemma is excessive CSI overhead versus limited feedback bandwith.

All-Optical Cochlear Implants

no code implementations20 Jun 2020 Stylianos E. Trevlakis, Alexandros-Apostolos A. Boulogeorgos, Nestor D. Chatzidiamantis, George K. Karagiannidis

In the present work, we introduce a novel cochlear implant (CI) architecture, namely all-optical CI (AOCI), which directly converts acoustic to optical signals capable of stimulating the cochlear neurons.

All

Analyzing Grant-Free Access for URLLC Service

no code implementations18 Feb 2020 Yan Liu, Yansha Deng, Maged Elkashlan, Arumugam Nallanathan, George K. Karagiannidis

Based on this framework, we define the latent access failure probability to characterize URLLC reliability and latency performances.

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