Researcher Collab

About

About Me

I am a Principal (Senior) Network Engineer and Chartered Engineer (CEng) with over two decades of experience at the intersection of Information Technology and Telecommunications. My professional and research focus lies in developing innovative, resilient, and scalable communication systems that integrate both theoretical rigor and real-world applicability.

I hold an MSc in Communications Engineering and Signal Processing, and I am an active member of several leading professional bodies, including the Institution of Engineering and Technology (MIET), the Institute of Physics (MInstP), the British Computer Society (MBCS), the Royal Aeronautical Society (ARAeS), and the IEEE (Senior Member, SMIEEE). These affiliations reflect my commitment to advancing engineering practice, promoting knowledge exchange, and supporting continuous professional and academic development.

My career has evolved through a balance of technical research, applied innovation, and leadership. As a Chartered Engineer, I combine advanced analytical methods with practical implementation to address complex challenges in communication networks. I have led multidisciplinary teams and contributed to projects where technical excellence, cost efficiency, and societal impact converge—particularly in the design of high-availability and mission-critical systems.

I place strong emphasis on clarity in communication and dissemination of knowledge, ensuring that research outcomes and technical concepts are both accessible and impactful. My professional ethos centers on creativity, methodological rigor, and ethical engineering practice.

Research and Technical Interests

- MIMO, Phased Array, and Microstrip Patch Antennas
- 5G/6G and IoT Communication Protocols
- Satellite and Autonomous Vehicle Communication Systems
- RF and Microwave Engineering
- AI-Driven Network Optimization and Systems Design

Alongside my professional work, I actively contribute to the academic community through research publications, mentoring, and collaborative projects that advance the frontiers of communication systems engineering.

I am honored to have recently commenced my PhD at the National and Kapodistrian University of Athens (NKUA).
My doctoral research, titled -“Advanced Design and Optimization of MIMO-Enabled Phased Array and Microstrip Patch Antennas for Enhanced Communication Protocols in Autonomous Vehicles and 5G/6G/IoT Satellite Networks: Enabling Accident Avoidance, Investigation, and Objective Incident Accountability and Documentation,”- explores next-generation antenna architectures that underpin intelligent, connected, and safety-oriented communication infrastructures.

I am always open to research collaborations, interdisciplinary projects, and academic partnerships that foster innovation and knowledge sharing. If our research interests align, I welcome the opportunity to connect and explore potential synergies.

Areas of Interest

Research and Technical Interests - MIMO Phased Array and Microstrip Patch Antennas - 5G/6G and IoT Communication Protocols - Satellite and Autonomous Vehicle Communication Systems - RF and Microwave Engineering - AI-Driven Network Optimization and Systems Design

Evolution of IVR building techniques: from code writing to AI-powered automation

arXiv.org
Authors: K. M. Shaikh and G. Giannakopoulos
Publish Year: 2024
Phased Array Antennas

Zenodo.org
Authors: G. Giannakopoulos and K. M. Shaikh
Publish Year: 2024
Enhanced Matched Filtering for Investigating Eye Diagrams in Baseband Binary Transmission

Preprints.org
Authors: G. Giannakopoulos, P. Adegbenro, and M. A. Perez
Publish Year: 2025
VHDL-Based Low-Power Modem Design Using QPSK and IIR Filters on Xilinx FPGA

Preprints.org
Authors: G. Giannakopoulos, M. A. Perez, and P. Adegbenro
Publish Year: 2025
Mobile Phone Studies Find No Short-Term Health Problems

Preprints.org
Authors: G. Giannakopoulos, K. M. Shaikh, and M. A. Perez
Publish Year: 2025
Phased Array Antennas: Advancements and Applications

Preprints.org
Authors: G. Giannakopoulos and K. M. Shaikh
Publish Year: 2025
Sustainable Practices in Green Engineering: A Pathway to a Greener Future using AI

Journal of Cloud Computing & Cybersecurity Innovations (JCCCI)
Authors: G. Giannakopoulos, K. M. Shaikh, M. A. Perez, and P. Adegbenro
Publish Year: 2025
A comprehensive study of IPTV: Challenges, opportunities, and future trends

Preprints.org
Authors: G. Giannakopoulos and K. M. Shaikh
Publish Year: 2025
The future of IPTV: Security, AI integration, 5G, and next-gen streaming

arXiv.org
Authors: G. Giannakopoulos, M. A. Perez, and P. Adegbenro
Publish Year: 2025
Phased Array Antennas for 5G and Beyond: Innovations and Implementation

Journal of Cloud Computing & Cybersecurity Innovations (JCCCI)
Authors: G. Giannakopoulos and K. M. Shaikh
Publish Year: 2025
Designing FIR and IIR Digital Filters for Low-Power Modems Using SIMULINK and VHDL

Preprints.org
Authors: G. Giannakopoulos, M. A. Perez, and P. Adegbenro
Publish Year: 2025
Sustainable Practices in Green Engineering: A Pathway to a Greener Future using AI

This article explores the integration of artificial intelligence (AI) and green engineering to address environmental challenges. It covers foundational principles of green engineering and AI's role in enhancing sustainable practices across sectors. The paper examines applications in sustainable energy systems, smart grids, and renewable energy, as well as AI's impact on sustainable design, manufacturing, and urban planning. It also addresses challenges including energy consumption, data privacy, and ethics. The article emphasizes interdisciplinary collaboration and provides insights for researchers, policymakers, and industry professionals working on environmental sustainability. It offers a comprehensive overview of the current state and future directions of AI-driven green engineering.

Authors: Georgios Giannakopoulos, Khushbu Mehboob Shaikh, Maria Antonnette Perez, Peter Adegbenro
Publish Year: 2025
Intelligent Automation and the Evolution of IT Strategy: A Systems Thinking Perspective

When organizations adopt systems thinking principles, systemic organizational change becomes more achievable through intelligent automation (IA). Implementing intelligent process automation--beyond the capabilities of robotic process automation--demands a departure from traditional, discrete-target methods, which often fail to unlock the full strategic potential of these advanced technologies. This study analyzes current research and real-world case studies to develop a system-based implementation model that emphasizes maintaining organizational interconnections, response cycles, and achieving equilibrium across all operational segments. Intelligent automation empowers organizations to develop a strategic vision by leveraging systems thinking methodologies, while simultaneously enhancing operational agility. This evolution elevates IT from a basic support function to a driver of enterprise-level strategic leadership. The research offers both theoretical and practical insights by aligning systems thinking principles with smart automation implementation, thereby providing IT leaders with a comprehensive framework for leveraging automation technologies as instruments of strategic business transformation.

Authors: Georgios Giannakopoulos, Vivek Singh
Publish Year: 2025
Applications of Monte Carlo Simulations in Medical Physics: Enhancing Precision and Accuracy in Radiation Therapy

Monte Carlo (MC) simulations are the backbone of medical physics, especially radiation therapy, due to their high accuracy in modeling the interaction of ionizing radiation with biological tissues. These significantly improve the accuracy of dose calculations and thus are of primary importance for treatment planning and quality assurance. Still, a high computational cost remains one of the substantial limiting factors for their wider use in clinical applications. This paper investigates the advantages of MC-based dose calculations compared to conventional algorithms; it underlines their superior precision and computational complexity. A comparative evaluation of MC techniques and deep learning-based methodologies is carried out in terms of performance with respect to accuracy, computational efficiency, and robustness in heterogeneous media. Results are presented that show Monte Carlo simulations reach up to 99.2\% accuracy but are computationally intensive, requiring substantial optimization through AI-driven acceleration techniques. Recent developments, such as GPU acceleration and hybrid AI-MC approaches, have shown great promise to close the gap between accuracy and computational feasibility. In addition, this study has demonstrated how AI-based variance reduction techniques contribute to the optimization of MC simulations by gaining execution time with no loss of their intrinsic accuracy. Future research efforts should focus on the development and integration of deep learning models in MC simulations to further advance the efficiency of MC simulations. These results of this study illustrated that hybrid AI-MC frameworks may achieve advances in computational efficiency while maintaining reliability for clinical use and thus can make Monte Carlo simulations more feasible in real-time medical applications.

Authors: Georgios Giannakopoulos
Publish Year: 2025
Enhanced Matched Filtering for Investigating Eye Diagrams in Baseband Binary Transmission

The aim of this paper is to study the performance of a matched filter for baseband binary transmission when subjected to Gaussian noise. A BER performance simulation model is created which consists of a BPSK encoder, a transmission SQRC filter, a Gaussian noise generator, a receive SQRT filter and a BPSK decoder. A Monte Carlo simulation technique is used to determine the dependency of BER performance on the signal to noise ratio. A MATLAB program and a MATLAB SIMULINK program was written to generate the required data. The MATLAB results show good agreement with statistical theoretical predictions.

Authors: Georgios Giannakopoulos, Peter Adegbenro, Maria Antonnette Perez
Publish Year: 2025
Computational Complexity of Radix-2, Radix-4 and Bluestein Algorithms Implementation of the Discrete Fourier Transform (DFT)

The computational complexity of Discrete Fourier Transform (DFT) algorithms plays a pivotal role in signal processing, influencing their applicability in various domains. This paper investigates three prominent Fast Fourier Transform (FFT) algorithms: Radix-2, Radix-4, and Bluestein, with a focus on their computational efficiency and suitability for different sequence lengths. MATLAB implementations were developed to optimize these algorithms, reducing the number of multiplications and additions required during runtime. A comparative analysis reveals that Radix-2 and Radix-4 algorithms are highly efficient for power-of-two and power-offour data lengths, respectively, while the Bluestein algorithm provides unparalleled flexibility for arbitrary sequence lengths, including primes. The study demonstrates the trade-offs associated with each algorithm, highlighting their strengths and limitations. Radix-4 achieves greater efficiency over Radix-2 for longer sequences, while Bluestein eliminates the need for zero-padding at the cost of increased computational complexity. This research offers valuable insights into the selection of FFT algorithms based on application-specific requirements and data characteristics, laying the groundwork for further optimization and hybrid algorithm development. The findings underscore the enduring importance of FFTs in addressing the computational demands of modern signal processing tasks.

Authors: Georgios Giannakopoulos, Khushbu Mehboob Shaikh, Maria Antonnette Perez
Publish Year: 2025
VHDL-Based Low-Power Modem Design Using QPSK and IIR Filters on Xilinx FPGA

This paper presents a low-power modem realized using Quadrature Phase Shift Keying (QPSK) modulation and Infinite Impulse Response (IIR) filters on a Xilinx FPGA. The architecture, designed for low-power wireless communication in mobile handsets, IoT, and battery-powered applications, incorporates 16−bit fixed-point IIR filters with power consumption of 40 mW. Adaptive voltage scaling reduces energy by another 15%, and clock gating and Dynamic Voltage Scaling (DVS) reduce total power consumption by up to 30%. Hardware-in-the-Loop (HIL) Bit Error Rate (BER) testing and in-situ power measurements confirm 98 mW total system power at 12 dB SNR, with a BER of 1.2 × 10−6. Compared to Finite Impulse Response (FIR)-based implementations, the new modem has 35% less latency and improved computational efficiency. The FPGA design is scalable and parallel-processing capable, making it easily implementable in real-time applications such as sensor networks, mobile communication, and SDR systems. The QPSK modulation is very efficient in terms of spectra, transmitting two bits per symbol and yet being extremely robust in noisy environments. The integration of the IIR filter also enhances signal quality by filtering out noise and optimizing the use of hardware resources. A comparative analysis explains the modem’s higher power efficiency, lower computational complexity, and superior performance over state-of-the-art designs. Future research efforts will consider adaptive modulation schemes, i.e., Orthogonal Frequency Division Multiplexing (OFDM), for spectral efficiency enhancement, and machine learning-based dynamic power management and hardware acceleration for further optimization. The suggested design provides a power-saving solution for next generation wireless communication, especially in systems with constrained energy resources.

Authors: Georgios Giannakopoulos, Khushbu Mehboob Shaikh, Peter Adegbenro
Publish Year: 2025
Mobile Phone Studies Find No Short-Term Health Problems

The increasing use of mobile phones worldwide has raised concerns about potential health risks associated with exposure to high-frequency radiation emitted by these devices. This study explores the short-term and potential long-term health effects of mobile phone usage, particularly focusing on risks such as cancer, nervous system disorders, and electromagnetic hypersensitivity. Key research conducted by organizations such as the World Health Organization (WHO) and the Mobile Telecommunications and Health Research (MTHR) program is reviewed, highlighting inconclusive evidence linking mobile phone radiation to health problems. Children and young users are identified as particularly vulnerable to potential risks, given their developing physiology and higher susceptibility to radiation absorption. Experimental studies investigating biological mechanisms, cognitive function, and hypersensitivity have largely found no conclusive evidence of harm, though long-term effects remain under-researched due to the relatively recent widespread adoption of mobile phones. The research article emphasizes the need for adherence to rigorous research methodologies, including randomized, double-blind experiments, and standardized statistical analyses to ensure reliable conclusions. Recommendations for reducing exposure, such as limiting mobile phone usage and adopting hands-free solutions, are provided as precautionary measures. While no definitive causal link has been established between mobile phone use and adverse health outcomes, ongoing research and cautious usage remain essential to safeguarding public health.

Authors: Georgios Giannakopoulos, Khushbu Mehboob Shaikh, Maria Antonnette Perez
Publish Year: 2025
Phased Array Antennas: Advancements and Applications

Phased array antennas provide the ability to electronically steer a beam, eliminating the need for mechanical adjustments [1]. While traditionally used in military applications, there is growing interest in their adoption across various fields [1,2]. Conformal antennas, a type of phased array, are designed for installation on curved or non-flat surfaces, enabling focused radio wave radiation [1,2]. These antennas can be integrated into various applications, including aerospace, wearable technology, vehicles, and modern mobile devices [2], while also reducing traditional antenna height to support the integration and coexistence of multiple radio technologies within a compact area [1,2]. Planar arrays, composed of elements with phase shifters in a matrix, are compact and cost-effective due to mass production via printed circuit technology [1–3]. These antennas, when mounted on rigid surfaces, exhibit robustness, provide beam deflection in two planes, and offer high gain with rapid beam-switching capabilities [1,3]. However, planar antennas can experience interference between feed lines and elements, often supporting narrow bandwidths and exhibiting relatively low radiation efficiency [1,3]. Conformal antennas, which are easily mounted on curved surfaces, are particularly suited for wearable applications, spacesuits, and aerospace designs [1,2,4]. By minimizing connection length, they bring electronics closer to the antenna elements, reducing signal loss while enhancing transmission power and receiver sensitivity, especially at higher frequencies [4]. Research into 3Dprinted conformal antennas has emerged as a significant field of study [1,5]. This paper presents the mathematical analysis of both planar and conformal antennas, covering key parameters such as gain, bandwidth, radiation efficiency, and mutual coupling for planar arrays, as well as the width and length calculations for rectangular microstrip patch antennas used in conformal designs [2,6–8]. Furthermore, the role of additive manufacturing in antenna development is highlighted, emphasizing its ability to produce antennas with complex geometries thereby revolutionizing conformal antenna design [1,9].

Authors: Georgios Giannakopoulos, Khushbu Mehboob Shaikh
Publish Year: 2025
A Comprehensive Study of IPTV: Challenges, Opportunities, and Future Trends

Internet Protocol Television (IPTV) is a transformative approach to delivering audio and video services through high-speed Internet networks, enabling direct access to television content via home computers or set-top boxes. Despite its promising advantages, including flexibility, interactivity, and bundled services such as triple play (voice, Internet, and TV) and quadruple play (adding mobile services), IPTV is still in its development phase. Key challenges include achieving a Quality of Service (QoS) comparable to traditional broadcasters, addressing limited bandwidth, and overcoming a lack of standardization among service providers. This paper explores the technical, operational, and consumer-oriented aspects of IPTV. It discusses data compression techniques, protocols like IGMP and RTSP, and the role of advanced codecs like H.264 in ensuring efficient data transmission. The study also examines the distinctions between IPTV and open-network Internet TV, the importance of security and privacy, and the emergence of new business opportunities through targeted advertising and interactive services. Although IPTV is unlikely to completely replace traditional broadcasting, it is poised to play an important role in shaping the future of television by offering personalized, secure, and scalable viewing experiences.

Authors: Georgios Giannakopoulos, Maria Antonnette Perez, Peter Adegbenro
Publish Year: 2025
Advanced Optimization Techniques for Enhancing Bandwidth and Gain in a 1.3 GHz Microstrip Patch Antenna Design for PAL TV Applications

This paper presents a systematic methodology for enhancing microstrip patch antenna (MPA) performance at 1.3 GHz for Phase Alternating Line (PAL) television broadcasting systems. Through the integration of slot-loaded patch geometries, substrate optimization, and array configurations, the proposed design achieves an 8.1 dBi gain and a 108 MHz bandwidth, representing improvements of 30% and 50% respectively, over conventional designs [1], [2]. The approach combines analytical modeling in MATLAB with full-wave electromagnetic simulations using CST Microwave Studio and is validated through precision measurements of fabricated prototypes. Key innovations include the implementation of a U-shaped slot for multi-resonant operation (∆f = 45 MHz per iteration), strategic selection of RT/Duroid 5880 substrate (ϵr = 2.2), and a 1 × 4 phased array configuration incorporating a defected ground structure (DGS) [5]. Experimental verification demonstrates 82% radiation efficiency and −22 dB cross-polarization isolation, fulfilling PAL TV specifications while maintaining compact dimensions (58 × 58 × 1.6 mm) [6], [7]. MATLAB and CST simulations analyze the antenna’s performance, including the reflection coefficient (S11) [11], [12]. The optimized MPA achieves a gain of 8 dBi with a bandwidth exceeding 100 MHz, aligning with the operational requirements of PAL TV applications [3], [13]. Future work will explore adaptive configurations and alternative substrate materials. [14], [15]

Authors: Georgios Giannakopoulos, Maria Antonnette Perez, Peter Adegbenro
Publish Year: 2025
Designing FIR and IIR Digital Filters for Low-Power Modems Using SIMULINK and VHDL

This paper presents a comprehensive study on the design and implementation of Finite Impulse Response (FIR) and Infinite Impulse Response (IIR) digital filters tailored for low-power modem applications. With the increasing demand for energy-efficient digital communication systems in Internet of Things (IoT) and mobile technologies, optimizing filters for power and performance is vital. FIR filters were designed using the windowing method, particularly the Hamming window, while IIR filters employed the bilinear transformation method to ensure stability and spectral accuracy. MATLAB was used for algorithmic design and frequency response analysis, whereas SIMULINK provided a dynamic environment to simulate real-time performance under varying signal conditions. The hardware realization was accomplished using VHDL, with synthesis and implementation carried out on FPGA platforms using Xilinx ISE. FIR filters were structured around a tap delay line architecture, offering inherent stability and linear phase characteristics, while IIR filters, though more complex due to feedback components, demonstrate superior power efficiency and sharper frequency cutoff characteristics. This study further explores the trade-offs between signal fidelity, computational complexity, and power consumption, providing insights through mathematical formulations, simulation results, and FPGA synthesis reports. Results indicate that FIR filters are advantageous in applications where linear phase response and stability are crucial, whereas IIR filters are preferable for constrained environments demanding minimal power usage. The comparative analysis suggests that filter selection should be application-specific, and future work may explore hybrid implementations that combine the advantages of both architectures for enhanced performance in next-generation communication systems.

Authors: Georgios Giannakopoulos, Peter Adegbenro, Maria Antonnette Perez
Publish Year: 2025
Securing the Future of IVR: AI-Driven Innovation with Agile Security, Data Regulation, and Ethical AI Integration

arXiv (Cornell University)

The rapid digitalization of communication systems has elevated Interactive Voice Response (IVR) technologies to become critical interfaces for customer engagement. With Artificial Intelligence (AI) now driving these platforms, ensuring secure, compliant, and ethically designed development practices is more imperative than ever. AI-powered IVRs leverage Natural Language Processing (NLP) and Machine Learning (ML) to personalize interactions, automate service delivery, and optimize user experiences. However, these innovations expose systems to heightened risks, including data privacy breaches, AI decision opacity, and model security vulnerabilities. This paper analyzes the evolution of IVRs from static code-based designs to adaptive AI-driven systems, presenting a cybersecurity-centric perspective. We propose a practical governance framework that embeds agile security principles, compliance with global data legislation, and user-centric ethics. Emphasizing privacy-by-design, adaptive risk modeling, and transparency, the paper argues that ethical AI integration is not a feature but a strategic imperative. Through this multidimensional lens, we highlight how modern IVRs can transition from communication tools to intelligent, secure, and accountable digital frontlines-resilient against emerging threats and aligned with societal expectations.

Authors: Khushbu Mehboob Shaikh, Georgios Giannakopoulos
Publish Year: 2025
Transnational Information Literacy Ecosystem Mapping (TILEM)

Zenodo (CERN European Organization for Nuclear Research)
Authors: Zervas Marios, Akroteriatou Myroulla, Kola Erasmia, Evagorou Athina, Nikolaidou Fotini, Kyprianou Maria, Kouis Dimitrios, Foteini Efthymiou, Kyriaki-Manessi Daphne, Georgios Giannakopoulos, Lazaridis Nikolaos, Marzal Garcia-Quismondo Miguel Ángel, Martínez-Cardama Sara, Parra-Valero Pablo, Brković Mirjana, Rudić Gordana, Pajić Dejan, Belić Natasa, Matić Ljiljana, Vasileiou Iro, Theodoridou Katerina
Publish Year: 2023
Design a 1.3 Ghz Microstrip Patch Antenna for a Pal TV Signal

Authors: Georgios Giannakopoulos
Publish Year: 2014
Low Power Modem Design

Authors: Georgios Giannakopoulos
Publish Year: 2015
Transnational Information Literacy Ecosystem Mapping (TILEM)

Zenodo (CERN European Organization for Nuclear Research)
Authors: Zervas Marios, Akroteriatou Myroulla, Kola Erasmia, Evagorou Athina, Nikolaidou Fotini, Kyprianou Maria, Kouis Dimitrios, Foteini Efthymiou, Kyriaki-Manessi Daphne, Georgios Giannakopoulos, Lazaridis Nikolaos, Marzal Garcia-Quismondo Miguel Ángel, Martínez-Cardama Sara, Parra-Valero Pablo, Brković Mirjana, Rudić Gordana, Pajić Dejan, Belić Natasa, Matić Ljiljana, Vasileiou Iro, Theodoridou Katerina
Publish Year: 2023
Transnational Information Literacy Ecosystem Mapping (TILEM)

Zenodo (CERN European Organization for Nuclear Research)
Authors: Zervas Marios, Akroteriatou Myroulla, Kola Erasmia, Evagorou Athina, Nikolaidou Fotini, Kyprianou Maria, Kouis Dimitrios, Foteini Efthymiou, Kyriaki-Manessi Daphne, Georgios Giannakopoulos, Lazaridis Nikolaos, Marzal Garcia-Quismondo Miguel Ángel, Martínez-Cardama Sara, Parra-Valero Pablo, Brković Mirjana, Rudić Gordana, Pajić Dejan, Belić Natasa, Matić Ljiljana, Vasileiou Iro, Theodoridou Katerina
Publish Year: 2023
ORCID VERIFIED PhD Georgios Giannakopoulos Engineering: Communication Engineering
National and Kapodistrian University of Athens
PhD Researcher in MIMO and Phased Array Antenna Design | Expert in 5G/6G, IoT, and Autonomous Communication Networks
Open 2 weeks ago

About Me I am a Principal (Senior) Network Engineer and Chartered Engineer (CEng) with over two decades of experience at the intersectio…

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