6 research outputs found
Utilisation des techniques avancées d’Emission / Réception multi-antennes pour une transmission optique large bande
Free space optical systems are potential candidates of large band spatial transmission solutions. In this thesis, FSO network architecture in the case of geo- stationary satellite to earth communication link is investigated and the influence of zenith angle on the quality of the link has been evaluated. Because of the variation of scintillation due to the complexity of the atmosphere, the optical space to earth communication link channel model has been developped. In order to overcome the main limitations of the prop- agation, optical relays with low earth orbit satellites and spatial diversity on earth could improve the link performance. To improve the link performance, an aggregated simulation model turbulence has been built based on parameters ”p” and ”1-p” introduced in the combined model a↵ecting the considered channels. The parameter ” p ” corresponds to the ratio of the distance from the earth to the relay over the total distance of 36 000Km. In the case of 1000 Km for a relay in the exosphere, p = 1/36. Simulation results show that the proposed network system architecture has outperformed the direct link performanceLes systèmes de communication FSO sont des candidats potentiels pour de solutions de transmission spatiale à large bande. C’est pourquoi la présente thèse s’inscrit dans une contribution d’une nouvelle architecture de réseau FSO dans le cas d’une liaison de communication entre un satellite géostationnaire et une station terrienne. Elle traite aussi de l’influence de l’angle zénithal sur la qualité de la liaison optique en raison de la variation de la scintillation due à la complexité de l’atmosphère. Nous avons établi un nouveau canal de communication tenant compte de la subdivision de l’atmosphère en deux grandes zones de turbulence. Pour améliorer la performance de la liaison, nous avons d’abord placé un relais AF optiques ente le satellite et la station terrienne, ensuite nous avons introduit un paramètre construit `a partir de valeurs : p et 1-p. Le paramètre p correspond au ratio de la distance entre la station terrienne et le relais sur la distance de 36 000 Km correspondant a` l’orbite GEO. Dans notre cas, le relais est placé a 1000 Km a l’exosphère, le paramètre p = 1/36 et enfin la technique de diversité spatiale est appliquée en réception. Les résultats de simulation ont confirmé que les architectures des systèmes proposés sont meilleures que les performances de liaisons optiques directes
Evolution to 200G Passive Optical Network
New generation passive optical network aims at providing more than 100 Gb/s
capacity. Thanks to recent progress enabling a variety of optical transceivers
up to 40 Gb/s, many evolution possibilities to 200G PONs (passive optical
network) could be investigated. This work proposes two directly deployable
cases of evolution to 200G PON based on the combination of these improved
optical transceivers and WDM (wavelength division multiplexing). The physical
layer of the optical network has been simulated with OptiSystem software to
show the communication links performances behavior when considering key
components parameters in order to achieve good network design for a given area.
The complexity of the proposed architectures and financial cost comparisons are
also discussed.Comment: http://www.davidpublishing.com/davidpublishing/Upfile/2/7/2013/2013020707494407.pd
Using advanced techniques Emission / Reception multi-antennas for broad- band optical transmission
Les systèmes de communication FSO sont des candidats potentiels pour de solutions de transmission spatiale à large bande. C’est pourquoi la présente thèse s’inscrit dans une contribution d’une nouvelle architecture de réseau FSO dans le cas d’une liaison de communication entre un satellite géostationnaire et une station terrienne. Elle traite aussi de l’influence de l’angle zénithal sur la qualité de la liaison optique en raison de la variation de la scintillation due à la complexité de l’atmosphère. Nous avons établi un nouveau canal de communication tenant compte de la subdivision de l’atmosphère en deux grandes zones de turbulence. Pour améliorer la performance de la liaison, nous avons d’abord placé un relais AF optiques ente le satellite et la station terrienne, ensuite nous avons introduit un paramètre construit `a partir de valeurs : p et 1-p. Le paramètre p correspond au ratio de la distance entre la station terrienne et le relais sur la distance de 36 000 Km correspondant a` l’orbite GEO. Dans notre cas, le relais est placé a 1000 Km a l’exosphère, le paramètre p = 1/36 et enfin la technique de diversité spatiale est appliquée en réception. Les résultats de simulation ont confirmé que les architectures des systèmes proposés sont meilleures que les performances de liaisons optiques directes.Free space optical systems are potential candidates of large band spatial transmission solutions. In this thesis, FSO network architecture in the case of geo- stationary satellite to earth communication link is investigated and the influence of zenith angle on the quality of the link has been evaluated. Because of the variation of scintillation due to the complexity of the atmosphere, the optical space to earth communication link channel model has been developped. In order to overcome the main limitations of the prop- agation, optical relays with low earth orbit satellites and spatial diversity on earth could improve the link performance. To improve the link performance, an aggregated simulation model turbulence has been built based on parameters ”p” and ”1-p” introduced in the combined model a↵ecting the considered channels. The parameter ” p ” corresponds to the ratio of the distance from the earth to the relay over the total distance of 36 000Km. In the case of 1000 Km for a relay in the exosphere, p = 1/36. Simulation results show that the proposed network system architecture has outperformed the direct link performanc
Investigation on free space optics network system architecture from geostationary orbit to earth
International audienceFree space optics (FSO) network architecture in the case of geostationary satellite to earth communication link is investigated in this paper. Because of the variation of scintillation due to the complexity of the atmosphere, the optical space to earth communication link channel model has been approximated by considering the atmosphere as strongly turbulent and the other layers as weakly turbulent. In order to overcome the main limitations of the propagation, optical relays with low earth orbit satellites and spatial diversity on earth could improve the link performance. Simulation results show that the proposed network system architecture has outperformed the direct link performance
Mitigating zenith angle limitations on spatial free space optical transmission link
International audienceFree space optical systems are potential candidates of large band spatial transmission solutions. This article investigates on the impact of relays to mitigate the zenith angle in the performance of a Free Space Optical (FSO) transmission. The high earth orbit communication channel has been approximated by considering the complexity of the atmosphere in two layers. The influence of zenith angle on the quality of the link has been evaluated. Appropriate network architecture scheme has been proposed. It is shown that it is possible to get a BER of 10-5 even when a zenith angle of 76.1° is considered