Orientadores: Edson Moschim, Marcelo Francisco Abbade / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Eletrica e de Computação / Made available in DSpace on 2018-08-11T13:37:23Z (GMT). No. of bitstreams: 1 Durand_FabioRenan_D.pdf: 1259125 bytes, checksum: 9e123c3d511429cff5a237aefb19765c (MD5) Previous issue date: 2007 / Resumo: Neste trabalho é realizada a análise da aplicação de códigos ópticos ortgonais (OOC) da tecnologia de multiplexação por divisão de códigos ópticos (OCDM) em redes ópticas híbridas multiplexadas pela divisão de comprimentos de onda e códigos ópticos (WDM)/OCDM e em redes ópticas comutadas por rajadas (OBS). As contribuições da tese consistem da proposta e análise da aplicação da camada de transporte WDM/OCDM em redes OBS roteadas por comprimento de onda (WR-OBS), modelagem matemática de comutadores ópticos (OXC) WDM/OCDM considerando os parâmetros dos códigos OOC, estudo dos efeitos da dispersão por polarização modal (PMD) em redes ópticas WDM/OCDM e, finalmente, a proposta e análise da utilização processamento óptico da sinalização baseada em códigos OOC. Em função dos resultados obtidos se verifica que a aplicação dos códigos ópticos OOC nas redes ópticas de transporte WDM/OCDM, redes de rajadas e redes WR-OBS aumenta o desempenho destas redes por meio da diminuição da probabilidade de perdas de pacotes, latência dos pacotes e aumento da utilização da rede. Palavras-chave: Códigos ópticos ortogonais (OOC), dispersão por polarização modal (PMD), redes ópticas WDM/OCDM, redes ópticas comutadas por rajadas (OBS) / Abstract: This work presents an analysis of optical orthogonal codes (OOC) of optical code division multiplexing (OCDM) in optical networks. These networks uses the hybrid technology of wavelength division multiplexing and optical code division multiplexing (WDM/OCDM) and, optical burst switching networks (OBS). The main contributions are the analyze and propose of WDM/OCDM transport network at wavelength routed OBS networks (WR-OBS), WDM/OCDM optical crossconnects (OXC) modeling considering OOC parameters, study of polarization mode dispersion (PMD) effects in optical WDM/OCDM networks and, finally an OBS architecture with OOC label processing is analyzed. Analytical and simulation results indicate that OOC utilization in WDM/OCDM transport networks, OBS and WR-OBS networks increases the network performance by decrease of packet error rate, latency and network utilization increase. Keywords: Orthogonal optical codes (OOC), polarization mode dispersion (PMD), WDM/OCDM optical networks, optical burst switching (OBS) / Doutorado / Telecomunicações e Telemática / Doutor em Engenharia Elétrica

Orientador : Helio Waldman / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Eletrica e de Computação / Made available in DSpace on 2018-08-04T03:23:02Z (GMT). No. of bitstreams: 1 AlmeidaJunior_RaulCamelodeAndrade_D.pdf: 6394727 bytes, checksum: 56d1667ed2e31b23492071088dcf7edf (MD5) Previous issue date: 2004 / Resumo: A combinação da comutação óptica de pacotes com a multiplexação por divisão de comprimento de onda (WDM) surge como um cenário promissor para as redes ópticas futuras. Um dos requisitos de projeto dessas redes é procurar minimizar a perda de pacotes quando há contendas pelos mesmos recursos. Uma alternativa é a utilização de armazenadores de pacotes ópticos, que fazem uso do domínio temporal para a resolução de contenção. Este trabalho propõe uma modelagem analítica para o desempenho desses dispositivos em redes ópticas assíncronas comutadas por pacote. Devido à inexistência de RAMs ópticas, os armazenadores de pacotes ópticos têm sido atualmente configurados por um conjunto de linhas de atraso capaz de prover um número finito de atrasos fixos. Considerando tal peculiaridade, uma contribuição adicional deste trabalho é a proposição e modelagem de duas políticas capazes de prover diferenciação de serviço em armazenadores de pacotes ópticos. Por fim, objetivando realizar um estudo comparativo entre três possíveis domínios de resolução de contenção, também são abordados os domínios espacial e do comprimento de onda, além da combinação entre eles e entre os domínios temporal e do comprimento de onda / Abstract: The combination of optical packet switching with wavelength division multiplexing (WDM) has emerged as a promising framework for future optical networks. One of the design requirements of these networks is to minimize the packet loss when there are contentions for the same resources. One possibility is to use optical buffers, which exploit the time domain for contention resolution. This work proposes an analytical modeling for the performance of such devices in asynchronous optical packet-switched networks. Due to the non-existence of optical RAMs, optical buffers have been designed using delay line banks that can provide a finite number of fixed delays. Considering such peculiarity, an additional contribution of this work is the proposal and modeling of two policies that can provide service differentiation in optical buffers. Lastly, in order to make a comparative study among three possible contention resolution domains, the space and wavelength domains are also analyzed, as well as their combinations and the combination between the time and wavelength domains / Doutorado / Telecomunicações e Telemática / Doutor em Engenharia Elétrica

D.Ing. / Optical fibre-based devices (e.g. fibre gratings) play an important role in the optical com- munications and sensing industry. One type of fibre grating, the long-period grating (LPG), is becoming more and more popular as a simple and versatile component for a multitude of applications in optical engineering. The sensitivity of LPGs to various external perturbations and their ability to manipulate selectively light propagating in optical fibres make them well- suited to creating fibre-based devices. LPGs can be used in various applications, for example as gain equalisers for erbium-doped fibre amplifiers, as channel routers in optical add-drop multiplexers and as sensors. LPGs are typically fabricated by exposing photosensitive optical fibre to ultraviolet light. However, a variety of other techniques can be used to fabricate LPGs, including exposure to carbon dioxide (CO2) laser light. Over the years, it has become evident that CO2 laser- induced LPGs exhibit unique properties and features that can be harnessed to develop devices for important applications. It is necessary to understand the physical properties and optical characteristics of CO2 laser-induced LPGs to harness, manipulate and enhance their features. Research has been conducted on the development of an automated fabrication system that produces axially symmetric LPGs in single-mode fibre with a CO2 laser. A detailed study was undertaken on the design of uniform and non-uniform LPGs for wavelength-division multiplexing networks, as well as the characterisation of the CO2 laser beam propagating in the LPG fabrication system. These LPGs have been designed, using either analysis or syn- thesis techniques. The polarisation-dependent loss of the LPGs has also been investigated. Wavelength-selective couplers (WSCs) have been constructed using CO2 laser-induced LPGs and it was shown that these couplers were e®ective but not efficient in routing power to the output port of the tapping fibre. The physical properties, optical transmission characteris- tics, applications and other related issues of CO2 laser-induced LPGs have been investigated and satisfactory experimental results have been obtained. Areas for potential future research concerning CO2 laser-induced LPGs have been identified and discussed.

We experimentally demonstrate an eight-state continuous-variable quantum key distribution (CV-QKD) over atmospheric turbulence channels. The high secret key rate (SKR) is enabled by 4-D multiplexing of 96 channels, i.e., six-channel wavelength-division multiplexing, four-channel orbital angular momentum multiplexing, two-channel polarization multiplexing, and two-channel spatial-position multiplexing. The atmospheric turbulence channel is emulated by a spatial light modulator on which a series of azimuthal phase patterns yielding Andrews' spectrum are recorded. A commercial coherent receiver is implemented at Bob's side, followed by a phase noise cancellation stage, where channel transmittance can be monitored accurately and phase noise can be effectively eliminated. Compared to four-state CV-QKD, eight-state CV-QKD protocol potentially provides a better performance by offering higher SKR, better excess noise tolerance, and longer secure transmission distance. In our proposed CV-QKD system, the minimum transmittances of 0.24 and 0.26 are required for OAM states of 2 (or -2) and 6 (or -6), respectively, to guarantee the secure transmission. A maximum SKR of 3.744 Gb/s is experimentally achievable, while a total SKR of 960 Mb/s can be obtained in case of mean channel transmittances.

Dans le cadre de l’avion plus électrique, les avionneurs cherchent à remplacer les commandes de vol hydrauliques par des commandes de vol électriques, avec pour intérêt de diminuer le poids, et d’améliorer la flexibilité des équipements aéronautiques. Sachant que sur un A380, la distance cumulée pour les câbles peut atteindre plus de 500 km, la solution consistant à faire cohabiter les transmissions de données et de puissances au sein de mêmes câbles grâce à la technologie CPL pourrait contribuer à réduire la masse de câble dans un avion. Cependant les câbles de puissance n’ont pas été dimensionnés pour transmettre un signal informationnel, et les équipements présents sur le réseau sont source de bruits. Dans ce contexte nous souhaitons montrer la faisabilité d’une transmission CPL soumise aux contraintes avioniques tout en respectant les normes aéronautiques. La première partie des travaux a consisté à mesurer le canal de propagation sur un banc de test représentatif d’un environnement aéronautique. Le canal de propagation est composé de deux coupleurs de type inductif ou capacitif dont le but est de connecter les câbles de télécommunication au réseau de puissance et d’une paire bifilaire torsadée de puissance d’une longueur de 32 m représentative d’un réseau HVDC ±270 V. Nous avons alors testé trois architectures différentes : l’architecture point-À-Point avec coupleur capacitif, l’architecture point-À-Point avec coupleur inductif et l’architecture point-À-Multipoints avec coupleur inductif. Le but de ces mesures a été d’évaluer la fonction de transfert du canal sur la bande [1 ; 100] MHz. Nous avons alors calculé les éléments caractéristiques du canal comme la bande de cohérence et l’étalement des retards. Après la caractérisation du canal de propagation, nous avons choisi et dimensionné les algorithmes de traitement du signal au regard des spécifications aéronautiques à savoir : un débit utile de 10 Mbit/s, un temps de latence de 167-334 μs, un TEB de 10-12 et le respect du gabarit de la DO-160 en émission conduite. Au regard de la fonction de transfert du canal, nous avons choisi d’utiliser l’OFDM comme technique de transmission. Ainsi, à l’aide de la caractérisation du canal de propagation nous avons au cours d’une étude paramétrique défini les paramètres de la transmission OFDM au regard des spécifications de débit et de temps réel. Dans un second temps, nous avons implanté les paramètres OFDM ainsi que la modélisation du canal de propagation dans une chaine de transmission Matlab. Cette chaine nous a alors permis de vérifier les paramètres issues de l’étude paramétrique ainsi que de définir le système de codage de canal (Reed-Solomon et code convolutif) pour respecter les spécifications aéronautiques. La dernière partie de cette thèse a consisté en l’étude du système de synchronisation. Du fait de la stabilité du canal de propagation, nous avons considéré une synchronisation fine du système lors d’une phase d’initialisation puis nous nous somme focalisé sur le dimensionnement d’un système de suivi dans le but de corriger le décalage de fenêtre FFT dû au défaut de fréquence d’échantillonnage. Pour limiter les pertes de débit lors de la phase de suivi, nous avons proposé une estimation de l’erreur de fréquence d’échantillonnage sur la phase des données reçues sur une période de 20 symboles OFDM. / In the new aircrafts, hydraulic flight control systems are replaced by electric flight control systems. The main interests are a better flexibility of the aeronautical equipments and a decrease in maintenance costs and construction costs, but the major problem is the increasing of the wires length. In order to decrease this length, it has been proposed to use power line communications (PLC) technology for flight control systems. The decrease of wire will first decrease aircraft weight and therefore the consumption of kerosene and on the other hand will simplify maintenance and construction. The first part of this work is the measurement and the characterisation of the propagation channel on an aeronautic test bench (with HVDC supply and loads). This channel is composed of two couplers (inductive or capacitive) in order to connect the telecommunication system on the power wires with galvanic isolation and one twisted pair of 32 m longs. We have tested three architectures: the point-To-Point architecture with capacitive coupler, the point-To-Point architecture with inductive coupler and the point-To-Multipoint architecture with inductive coupler. The purpose of these measurements is to measured the transfer function on the [1 ; 100] MHz bandwidth. Then, we have computed the channel parameters like the coherence bandwidth and the delay spread. The second step was the design of the signal processing algorithm in order to satisfy the aeronautical specifications: a useful bite rate of 10 Mbit/s, a latency of 167- 334 μs, a BER of 10-12 and the respect of the DO-160 gauge in conducted emissions. For the transmissions, we have chosen the OFDM technology which has been use with success in other PLC systems. With the channel characterization, we have proposed a parametric study in order to define the OFDM parameters to satisfy the bite rate and the real time constraints. After, we compute digital simulations with Matlab to check the OFDM parameters. With these simulations, we have also defined the channel coding parameters (Reed-Solomon and convolutional coding) to satisfy the aeronautical specifications. The last part of this study was the design of the synchronisation system. Because of the channel stability, we considered a precise synchronisation after an initialisation period. Then, we focus on the estimation of the FFT shift, due to the sampling frequency shift, during a following-Up period. In order to avoid the decrease of the latency and the bitrate due to the pilot symbols or pilot sub-Carriers insertion, we proposed to correct the FFT shift with the receive data thanks to the maximal likelihood algorithm.

Previously, we proposed and experimentally demonstrated enhanced recording speeds by using a resonant optical cavity to semi-passively increase the reference beam power while recording image bearing holograms. In addition to enhancing the reference beam power the cavity supports the orthogonal reference beam families of its eigenmodes, which can be used as a degree of freedom to multiplex data pages and increase storage densities for volume Holographic Data Storage Systems (HDSS). While keeping the increased recording speed of a cavity enhanced reference arm, image bearing holograms are multiplexed by orthogonal phase code multiplexing via Hermite-Gaussian eigenmodes in a Fe: LiNbO3 medium with a 532 nm laser at two Bragg angles for expedited recording of four multiplexed holograms. We experimentally confirmed write rates are enhanced by an average factor of 1.1, and page crosstalk is about 2.5%. This hybrid multiplexing opens up a pathway to increase storage density while minimizing modifications to current angular multiplexing HDSS.

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During the last three decades, the significant increase in electricity demand, and its consequences, has appeared as a serious concern for the utility companies, but no major changes have been applied to the conventional power grid infrastructure. Recently, researchers have identified efficient control and power distribution mechanisms as the immediate challenges for conventional power grids. The next step for conventional power grid towards the Smart Grid is to provide energy efficiency management along with higher reliability via smart services, in which the application of Information and Communication Technology (ICT) is inevitable. ICT introduces powerful tools to comply with the smart grid requirements. Among various ICT properties, the telecommunication network plays a key role for providing a secure infrastructure. The two-way digital communication system provides an interaction between energy suppliers and consumers for managing, controlling and optimizing energy distribution. We can also define the smart grid as a two-way flow of energy and control information, where the electricity consumers can generate energy using green energy resources. The main objective of this thesis is to select an effective data communication infrastructure to support the smart grid services by considering a hybrid wireless and optical communication technologies. Radio-over-Fibre (RoF) networks are considered as a potential solution to provide a fast, reliable and efficient network backbone with the optical access network integration and the flexibility and mobility of the wireless network. Therefore, we adopt the integration of RoF to Passive Optical Network (PON) as a broadband access network to transmit smart grid data along with the Fiber to the Home/Building/Curb (FTTx) traffic through the shared fibre, and utilizing Wavelength Division Multiplexing (WDM). Finally, we present and analyze the simulation results for the aforementioned infrastructure based on our enhanced ROF-PON integration model.

L'évolution rapide dans les systèmes de communications sansfil couplée à l'utilisation de téléphones mobiles, des services satellite, de l'internet sur les réseaux sans fil et les réseaux locaux nécessitent un débit de données très élevé et une grande fiabilité. Ces débits ont augmenté rapidement dans les nouvelles applications de transmission de données de nouvelle génération. Pour répondre aux contraintes de la limitation du spectre disponible, les systèmes à porteuses multiples (OFDM), permettent une haute efficacité spectrale à cause de l'orthogonalité et un débit total s'approchant du débit de Nyquist. Par ailleurs, un système de réseaux des antennes à multi-entrées et multi-sorties (MIMO) apporte des gains importants, à la fois, pour les liens et les capacités du réseau, sans transmission de puissance supplémentaire ou sans consommation de la bande passante. La combinaison de ces deux systèmes (MIMO et OFDM) permet d’exploiter la robustesse de la liaison sur des canaux sélectifs en fréquence et sur des canaux non corrélés en espace. Une des problématiques de cette combinaison réside dans les méthodes de synchronisation. La synchronisation se divise en deux parties, la synchronisation temporelle et la synchronisation fréquentielle. La synchronisation temporelle se fait, d'une part par la synchronisation grossière qui consiste à estimer le début de chaque trame reçue, et d'autre par la synchronisation fine qui détecte le début de chaque symbole OFDM dans la trame reçue. Le principe de la synchronisation fréquentielle est de trouver le déphasage entre la fréquence à l'émission et la fréquence locale du récepteur. Dans une première partie, nous avons proposé des méthodes pour la synchronisation temporelle en se basant sur des séquences de synchronisation connues au niveau du récepteur. Nous avons réalisé une étude des différentes séquences existantes afin de comparer les efficacités de chacune de ces séquences pour la synchronisation dans un système MIMOOFDM. Dans une deuxième partie, un travail de simulation sous Matlab a été réalisé afin d'étudier les performances de nos méthodes proposées dans des canaux sélectifs en fréquence et à trajets multiples. Les résultats de simulations de ces méthodes expriment la probabilité d’acquisition de synchronisation temporelle selon le SNR. / The current wireless communication systems, mobile phones, satellite services and wireless internet networks require a very high data rate and a highly reliable degree. These rates have increased rapidly in the new applications of data transmission of new generation. To take into account the spectrum limitations, the OFDM has been proposed thanks the orthogonality between sub-carriers and the data rate that approaches to the Nyquist-Shannon sampling rate. Furthermore, the antennas technic (MIMO) can provide significant various gains, a diversity gain that improves the link reliability and the spatial multiplexing gain where different data streams are transmitted over different antennas. The combination of these two systems (MIMO and OFDM) allows to exploit the robustness of the link on the frequency-selective channels and uncorrelated channels in space. One of the issue in the combination MIO-OFDM resides on the synchronization methods. The synchronization is divided into sub parts, timing synchronization and frequency synchronization. Timing synchronization is also divided into two parts, firstly, the coarse timing synchronization is used to estimate the beginning of each received frame, and secondly, the fine timing synchronization which detects the beginning of each OFDM symbol in the received frame. The principle of the frequency synchronization is to find the shifted phase between the transmitted frequency and the local frequency at the receiver. In a first part, we have proposed different methods for timing synchronization based on synchronization sequences known at the receiver. We did a study for various existing sequences to compare the efficiencies of each of these sequences in timing synchronization for MIMO-OFDM systems. In a second part, Matlab’s simulations were conducted to study the performance of our proposed methods in multi-paths frequency-selective channels. Simulations results show the acquisition timing synchronization probability in terms of SNR.

This dissertation introduces three novel multiuser detection approaches in Multiple Input Multiple Output (MIMO) Orthogonal Frequency Division Multiplexing (OFDM) systems by blind signal separation (BSS) techniques. The conventional methodologies for multiuser detection have to retransmit channel state information (CSI) constantly from the transmitter in MIMO ODFM systems at the cost of economic efficiency, because they require more channel resources to improve the communication quality. Compared with the traditional methodologies, the proposed BSS methods are relatively efficient approaches without the unnecessary retransmission of channel state information. The current methodologies apply the space-time coding or the spatial multiplexing to implement an MIMO OFDM system, which requires relatively complex antenna design and allocation in the transmitter. The proposed Spatial Division Multiple Access (SDMA) method enables different mobile users to share the same bandwidth simultaneously in different geographical locations, and this scheme requires only one antenna for each mobile user. Therefore, it greatly simplifies the antenna design and allocation. The goal of this dissertation is to design and implement three blind multiuser detection schemes without knowing the channel state information or the channel transfer function in the SDMA-based uplink MIMO OFDM system. The proposed scenarios include: (a) the BSS-only scheme, (b) the BSS-Minimum Mean Square Error (MMSE) scheme, and (c) the BSS-Minimum Bit Error Ratio (MBER) scheme. The major contributions of the dissertation include: (a) the three proposed schemes save the commercially expensive cost of channel resources; (b) the proposed SDMA-based uplink MIMO OFDM system simplifies the requirements of antennas for mobile users; (c) the three proposed schemes obtain high parallel computing efficiency through paralleled subcarriers; (d) the proposed BSS-MBER scheme gains the best BER performance; (e) the proposed BSS-MMSE method yields the best computational efficiency; and (f) the proposed BSS-only scenario balances the BER performance and computational complexity.