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Annonce

11 février 2021

PhD Thesis on Hybrid RF/Optical Communications - Ecole Centrale Marseille


Catégorie : Doctorant


PhD Thesis at Ecole Centrale Marseille:

The aim of this thesis is to develop very high-speed data transmission solutions to allow the establishment of robust communication links between underwater vehicles and an aerial platform. The connection is established between the underwater vehicle and the sea surface, and then relayed by a link between the surface and the aerial platform. The major challenge is to design a system that can adapt the transmission parameters and optimize them in real time to ensure a reliable connection in an environment which can be highly dynamic and variable. Meanwhile, solutions for enhacing the data transmission security will be proposed for the considered application scenarios.

 

Main objectives:

The aim of this thesis is to develop very high-speed data transmission solutions to allow the establishment of robust communication links between underwater vehicles and an aerial platform. The connection is established between the underwater vehicle and the sea surface, and then relayed by a link between the surface and the aerial platform. The major challenge is to design a system that can adapt the transmission parameters and optimize them in real time to ensure a reliable connection in an environment which can be highly dynamic and variable. Meanwhile, solutions for enhacing the data transmission security will be proposed for the considered application scenarios.

Description of the proposed project :

The first objective of the thesis is to propose efficient solutions to increase the robustness of UWOC links in challenging deployment scenarios. We will rely on the mathematical models already developed in our lab (Fresnel Institute) for the aquatic channel and the optical link to focus on the data transmission and signal processing aspects.

First, the impact of various phenomena related to the aquatic environment will be studied on the quality of data transmission in an underwater wireless optical communication (UWOC) link. Appropriate solutions will then be proposed to increase the robustness of such links, in particular against pointing errors. These solutions will include "classical" signal processing techniques, as well as those based on machine learning to adapt the parameters of the transmission system to the changing link properties. The relevance and reliability of these solutions will be assessed experimentally using a UWOC transmission testbed, available at the Fresnel Institute. Full-scale tests could also be considered thanks to the support of our industrial partners. We will also investigate the performance of Quantum key distribution (QKD) protocols over underwater links focusing on the unique features of the underwater channel in comparison to atmospheric or fiber channels.

The second objective of the thesis is to achieve a high-speed and robust link between the sea surface and an aerial platform. We will then work on the design of a radiofrequency (RF) communication link established between the surface and this platform. This requires the design of the relay node which will be responsible for the optical/RF signal conversion with strict criteria in terms of energy efficiency, conversion "fidelity", and implementation complexity.

Past experience and collaborations:

Our research lab has a rich experience of more than 10 years on the UWOC technology with a number of contributions of strong impact at the international level. This thesis will be carried out in close collaboration with the "LiFi Research Center" laboratory at the University of Edinburgh with several planned short stays throughout the thesis duration. It will also receive support from a European collaboration network, currently coordinated by the Fresnel Institute (H2020 COST Action CA19111). Also, this work will benefit from regular discussions with our industrial partners.

Required skills:

The candidate must have a Master (MSc or equivalent) degree by Sept. 2021. The start of the thesis is planned for Sept./Oct. 2021.

A solid background in signal processing techniques is an important asset, as well as a good knowledge of optics and optoelectronics. An experience or training in digital communications is also very welcome. The candidate must have a very good English language proficiency (oral and written expression) and be keen for short-term stays in partner laboratories.

Contact:

Interested candidates are requested to send their CV and cover letter by email before 20 March 2021 to Dr. Ali Khalighi, Email: Ali.Khalighi@fresnel.fr

References:

[1] M.A. Khalighi et al., “Underwater Wireless Optical Communication; Recent Advances and Remaining Challenges,” Invited paper, International Conference on Transparent Optical Networks, July 2014, Graz, Austria.

[2] M.A. Khalighi et al.,Underwater Visible Light Communications, Channel Modeling and System Design, Visible Light Communications, Theory and Applications, CRC Press, 2017

[3] C. Gabriel et al., “Monte-carlo-based channel characterization for underwater optical communication systems,” Journal of Optical Communications & Networking, vol. 5, no. 1, Jan. 2013.

[4] M.A. Khalighi et al., "Underwater Wireless Optical Communications Using Silicon Photo-multipliers," IEEE Photonics Journal, Vol. 9, No. 4, Aug. 2017.

[5] T. Hamza et al, "Investigation of Solar Noise Impact on the Performance of Underwater Wireless Optical Communication Links," Optics Express, Vol. 24, No. 22, 31 Oct. 2016.

[6] F. Mattoussi et al., "Improving the Performance of Underwater Wireless Optical Communication Links by Channel Coding," Applied Optics, Vol.5, No.9, pp. 2115-2120, Mar. 2018.

[7] M.A. Khalighi et al., “Silicon-Photomultiplier-Based Underwater Wireless Optical Communication Using Pulse-Amplitude Modulation,” IEEE Journal of Oceanic Engineering, 2019.

[8] A.S. Ghazy et al., “Angular MIMO for Underwater Wireless Optical Communications: Channel Modelling and Capacity,” IEEE Canadian Workshop on Information Theory, 2019, Hamilton, Canada

[9] T. Essalih et al., “Optical OFDM for SiPM-Based Underwater Optical Wireless Communication Links,” Invited paper, MDPI Sensors, Special Issue on Visible Light Communication, Networking, and Sensing, 2020

[10] A. H. F. Raouf, M. Safari, and M. Uysal, "Multi-hop quantum key distribution with passive relays over underwater turbulence channels," Journal of Optical Society of America B, 37, pp. 3614-3621, 2020.

[11] N. Gisin, G. Ribordy, W. Tittel, H. Zbinden, "Quantum cryptography," Rev. Mod. Phys. 74, 2002.



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