Chapter in a book published


We have just been informed that our chapter entitled “Hearing Restoration through Optical Wireless Cochlear Implants” is online and publicly available. You can find it at the following here.

In this chapter, we present a vision for next-generation cochlear implants. In particular, we present two novel optical wireless-based cochlear implant architectures: (i) optical wireless cochlear implant (OWCI) and (ii) all-optical cochlear implant (AOCI). Both the architectures aim to decisively improve the reliability and energy efficiency of hearing restoration devices. To provide design and development guidelines, we document their main components, discuss the particularities of the transdermal optical channel, and provide the analytical framework for their accurate modeling. Building upon this framework, we extract closed-form formulas that quantify the communication, the stimulation, and the overall performance. An overall comparison of OWCI and AOCI, as well as conventional cochlear implants, accompanied by future research directions, summarizes this chapter. Our findings reveal that both the OWCI and the AOCI outperform conventional cochlear implant approaches; thus, they are identified as promising architectures for the next generation of cochlear implants.

Papers included in the most popular lists for the month March 2022


Good news! According to #IEEEXplore, in March, six (6) of our papers were included in the corresponding journals’ lists of the most popular contributions. The papers are:

[1] A.-A. A. Boulogeorgos, J. M. Jornet and A. Alexiou, “Directional Terahertz Communication Systems for 6G: Fact Check,” in IEEE Vehicular Technology Magazine, vol. 16, no. 4, pp. 68-77, Dec. 2021, doi: 10.1109/MVT.2021.3113883.

[2] T. A. Tsiftsis, C. Valagiannopoulos, H. Liu, A.-A. A. Boulogeorgos and N. I. Miridakis, “Metasurface-Coated Devices: A New Paradigm for Energy-Efficient and Secure 6G Communications,” in IEEE Vehicular Technology Magazine, vol. 17, no. 1, pp. 27-36, March 2022, doi: 10.1109/MVT.2021.3119282.

[3] S. E. Trevlakis, A.-A. A. Boulogeorgos, N. D. Chatzidiamantis and G. K. Karagiannidis, “All-Optical Cochlear Implants,” in IEEE Transactions on Molecular, Biological and Multi-Scale Communications, vol. 6, no. 1, pp. 13-24, July 2020, doi: 10.1109/TMBMC.2020.2996629.

[4] A.-A. A. Boulogeorgos, S. E. Trevlakis, S. A. Tegos, V. K. Papanikolaou and G. K. Karagiannidis, “Machine Learning in Nano-Scale Biomedical Engineering,” in IEEE Transactions on Molecular, Biological and Multi-Scale Communications, vol. 7, no. 1, pp. 10-39, March 2021, doi: 10.1109/TMBMC.2020.3035383.

[5] A. -A. A. Boulogeorgos and A. Alexiou, “Coverage Analysis of Reconfigurable Intelligent Surface Assisted THz Wireless Systems,” in IEEE Open Journal of Vehicular Technology, vol. 2, pp. 94-110, 2021, doi: 10.1109/OJVT.2021.3051209.

[6] D. Pliatsios, S. K. Goudos, T. Lagkas, V. Argyriou, A. -A. A. Boulogeorgos and P. Sarigiannidis, “Drone-Base-Station for Next-Generation Internet-of-Things: A Comparison of Swarm Intelligence Approaches,” in IEEE Open Journal of Antennas and Propagation, vol. 3, pp. 32-47, 2022, doi: 10.1109/OJAP.2021.3133459.

I would like to thank my co-authors, colleagues, and friends for their help and contributions.

Paper accepted for publication!


Let me share with you some good news!!! We were just informed that our paper entitled “A Quantitative Look at Directional Terahertz Communication Systems for 6G: Fact Check” was accepted for publication in IEEE Vehicular Technology Magazine (Impact factor: 10.384). I would like to thank my co-authors ‪Josep Miquel Jornet‬ and Angeliki Alexiou for their great collaboration. The abstract of the paper is:Abstract: Sustaining a flexible and ubiquitously available high-data-rate network, capable of supporting a massive number of end-users, demands the exploitation of higher frequency bands, such as the terahertz (THz) band (0.1-10~THz). However, the utilization of THz wireless systems comes with a number of challenges, many of them associated with the very high propagation losses of THz signals, which require the utilization of high-gain directional antennas with strict beam alignment requirements, as well as the low signal penetration of (sub) millimetric waves, which leads to intermittent blockage and shadow areas. In this paper, a quantitative discussion of these phenomena and their implications in both backhaul and fronthaul applications of the THz spectrum is provided. Starting from state-of-the-art demonstrated THz technology parameters, the directivity requirements, the impact of beam misalignment, and the opportunities for multi-hop relaying in two different application scenarios are described. For the same conditions, the impact of blockage is quantified, and the benefits of reconfigurable intelligent surfaces are studied. Finally, the implications of blockage on the physical layer security of THz systems are presented.

Paper accepted for publication


Let me share with you some great news! Our paper entitled “An Experimentally Validated Fading Model for THz Wireless Systems” has been accepted for publication in Scientific Reports. It is worth noting that Scientific Reports belongs to the journals of Nature family.

Abstract: As the wireless world moves towards the sixth generation (6G) era, the demand for supporting bandwidth-hungry applications in ultra-dense deployments becomes more and more imperative. Driven by this requirement, both the research and development communities have turned their attention to the terahertz (THz) band, where more than 20 GHz of contiguous bandwidth can be exploited. As a result, novel wireless systems and network architectures have been reported promising excellence in terms of reliability, massive connectivity, and data rates. To assess their feasibility and efficiency, it is necessary to develop stochastic channel models that account for the small-scale fading. However, to the best of our knowledge, only initial steps have been so far performed. Motivated by this, this contribution is devoted to take a new look to fading in THz wireless systems, based on three sets of experimental measurements. In more detail, measurements, which have been conducted in a shopping mall, an airport check-in area, and an entrance hall of a university towards different time periods, are used to accurately model the fading distribution. Interestingly, our analysis shows that conventional distributions, such as Rayleigh, Rice, and Nakagami-m, lack fitting accuracy, whereas, the more general, yet tractable, α-µ distribution has an almost-excellent fit. In order to quantify their fitting efficiency, we used two well-defined and widely accepted tests, namely the Kolmogorov-Smirnov and the Kullback-Leibler tests. By accurately modeling the THz wireless channel, this work creates the fundamental tools for developing the theoretical and optimization frameworks for such systems and networks.