On 11th June 2019, Karim Elayoubi defended his thesis. Awarded by ISAE-SUPAERO, his work was supervised by both ISAE-ONERA OLIMPES, GEET doctoral school, and IRT Saint Exupéry. The high quality and the relevance of Karim thesis contributed to get significant results as a part of ALBS project.

THESIS SUBJECT

“Study of communication chains for optical links through the atmosphere”

About this thesis

Due to expected capacity bottlenecks of exploited microwave technologies, feeder links for data relay or broadband access systems will require the implementation of high capacity optical communication links between space and the ground. In this context, it is necessary to detail the investigation of the optical technologies and techniques that could enable the transmission of high data rates at optical frequencies through the Earth’s atmosphere, with regard to all kinds of the atmospheric phenomena. In particular, the adverse effects of atmospheric turbulence fading are of special relevance to optical communication systems for ground-to-space uplink applications. Although previous studies and experiments have demonstrated the feasibility of such optical links at low data rate, research is still needed to identify technical solutions and strategies adapted to the specific constraints imposed to these high-speed links in order to ensure the required level of performance. Against this background, various test benches have been developed to characterize different modulations and detection techniques for optical communication systems prior to be incorporated in the conceptual design of future 1-Tb/s ground-space optical links. The expected performances of such experimental demonstration are derived based on simulation models taking into account the atmospheric turbulence effects, in order to prove the feasibility of reliable ground-to-space high date rate optical communication links. The main objective of this thesis is the investigation of the free space optical communication through the atmosphere under different turbulence regimes. Both of simulation and experimentation of such communications are considered and the associated results are detailed.

ALBS PROJECT

Ground processing and transmission chains for RF and optical broadband satellite communication systems (new waveforms, interference and distortions management, ground stations handover, ground optical terminals).

Jury

A. SHARAIHA	Rapporter	Professor / ENIB
C. AUPETIT-BERTHELEMOT	Rapporter	Professor / ENSIL, XLIM laboratory
A. BELMONTE	Examiner	Professor / Technical University of Catalonia, BarcelonaTech
C. PEUCHERET	Examiner	Professor / ENSSAT, Université Rennes 1, Foton Institute
AL. BILLABERT	Examiner	Lecturer / CNAM
A. RISSONS	Thesis Director	Professor / ISAE-SUPAERO
J. LACAN	Thesis co-Director	Professor / ISAE-SUPAERO

PUBLICATIONS

• Optical test bench experiments for 1-Tb/s satellite feeder uplinks – K. Elayoubi, A. Rissons and A. Belmonte – SPIE Optical Engineering + Applications – Laser Communication and Propagation through the Atmosphere and Oceans VII (Society of Photo-Optical Instrumentation Engineers) – San Diego, USA – 2018 – DOI
• RZ-DPSK Optical Modulation For free Space Optical Communication by Satellites – K. Elayoubi, A. Rissons, J. Lacan, L. Saint Antonin, M. Sotom and A. Le Kernec – IEEE – OECC & PGC 2017 (Opto-Electronics and Communications Conference & Photonics Global Conference) – Singapore, Republic of Singapore – DOI
• Optical receiver sensitivity improvement using RZ-DPSK for Free Space Optical Communication by Satellites – K. Elayoubi, A. Rissons, J. Lacan, L. Saint Antonin, M. Sotom and A. Le Kerne –  ICO 24 (24th congress of the International Commission of Optics) – Tokyo, Japan – 2017
• Génération des formes d’ondes optiques pour la communication à travers l’atmosphère – K. Elayoubi, L. Saint Antonin, A. Le Kernec, M. Sotom, A. Rissons and J. Lacan –  Journée du Club Optique et Micro Onde 2016 – Nice, France