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Modulations A Haute Efficacite Spectrale Pour Les Transmissions Non Coherentes
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Book Synopsis MODULATIONS A HAUTE EFFICACITE SPECTRALE POUR LES TRANSMISSIONS NON COHERENTES by : Céline Durand
Download or read book MODULATIONS A HAUTE EFFICACITE SPECTRALE POUR LES TRANSMISSIONS NON COHERENTES written by Céline Durand and published by . This book was released on 2000 with total page 187 pages. Available in PDF, EPUB and Kindle. Book excerpt: LES APPLICATIONS RECENTES ET FUTURES DU DOMAINE DES TELECOMMUNICATIONS REQUIERENT TOUJOURS PLUS DE BANDE PASSANTE ET LES DEBITS BINAIRES SONT DE L'ORDRE DE QUELQUES CENTAINES A QUELQUES MILLIERS DE KBITS/S. L'ACCES A DE TELS SERVICES DOIT ETRE POSSIBLE DEPUIS UN NOMBRE GRANDISSANT DE RESEAUX. C'EST POURQUOI UN USAGE ENCORE PLUS EFFICACE DES RESSOURCES EST NECESSAIRE. LA MISE EN UVRE OU NON DE MECANISMES DE RECUPERATION DE LA PHASE PERMET DE DISTINGUER LA DETECTION COHERENTE DE LA DETECTION NON COHERENTE ; CETTE DERNIERE SE COMPORTE TRES BIEN FACE AUX CONDITIONS DE TRANSMISSION DIFFICILES ET PERMET LA REALISATION DE TERMINAUX ROBUSTES ET PEU COUTEUX. LES MODULATIONS NON COHERENTES CLASSIQUES (Q-FSK, OOK, ET LEURS VARIANTES) SOUFFRENT DE LEUR FAIBLE EFFICACITE SPECTRALE, MAIS CELLE-CI PEUT ETRE AUGMENTEE A L'AIDE DE SIGNAUX MULTIDIMENSIONNELS A COMPOSANTES CORRELEES ALORS QUE TOUT OU PARTIE DE LA DEGRADATION DES PERFORMANCES EST COMPENSEE. CES TRAVAUX METTENT L'ACCENT SUR DES MODULATIONS A HAUTE EFFICACITE SPECTRALE POUR LES TRANSMISSIONS NON COHERENTES. NOUS CHERCHONS ET ETUDIONS DES METHODES DE CONSTRUCTION D'ALPHABETS NON TRIVIAUX POUR LES CANAUX GAUSSIEN ET DE RAYLEIGH. LES ALPHABETS MULTIDIMENSIONNELS OBTENUS SONT CONSTRUITS A PARTIR DE SIGNAUX CORRELES - SIGNAUX D'UNE MODULATION FSK OU SEQUENCES D'ETALEMENT. TROIS CONSTRUCTIONS SONT FONDEES SUR LES SIGNAUX FSK : LES RESEAUX DE FREQUENCES DONT L'ETUDE REPOSE SUR LA THEORIE DES RESEAUX DE POINTS, LES ALPHABETS CODES PAR UNE TCM ET LES BICM POUR LESQUELLES UNE DETECTION ITERATIVE COMBINEE A UN DECODAGE SOUPLE CONDUIT AUX MEILLEURS RESULTATS. SI DES ALPHABETS PLUS GRANDS SONT NECESSAIRES, NOUS SUGGERONS L'EMPLOI DE SEQUENCES D'ETALEMENT COMPLEXES CORRELEES QUI PERMETTENT DE S'AFFRANCHIR DE TOUTE LIMITE THEORIQUE D'EFFICACITE SPECTRALE - HORMIS LA CAPACITE DU CANAL COHERENT - ET D'APPROCHER PAR DES SYSTEMES DE TRANSMISSION AVEC DETECTION NON COHERENTE, LES PERFORMANCES DE LA DETECTION COHERENTE.
Book Synopsis Modulations à haute efficacité spectrale pour les transmissions non cohérentes by : Céline Durand
Download or read book Modulations à haute efficacité spectrale pour les transmissions non cohérentes written by Céline Durand and published by . This book was released on 2000 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Techniques de traitement numérique du signal pour les systèmes de transmission optique ultra haut débit à détection cohérente by : Omid Zia-Chahabi
Download or read book Techniques de traitement numérique du signal pour les systèmes de transmission optique ultra haut débit à détection cohérente written by Omid Zia-Chahabi and published by . This book was released on 2013 with total page 108 pages. Available in PDF, EPUB and Kindle. Book excerpt: La détection optique cohérente et le traitement numérique du signal sont au coeur de la nouvelle génération de systèmes de transmission sur fibre. Ces systèmes utilisent des formats de modulation à grande efficacité spectrale et sont très robustes à la propagation sur le canal de transmission optique. Ils offrent ainsi aux opérateurs de télécommunications la possibilité de décupler la capacité de leurs réseaux de transport tout en conservant leurs infrastructures fibre existantes. Cette thèse développe différentes problématiques relatives à la conception de fonctions numériques pour les récepteurs optiques à détection cohérente fonctionnant aux débits de 100 Gbit/s et au-delà. Elle aborde les aspects de complexité calculatoire de l'égalisation numérique du canal optique, puis évalue l'apport des techniques dans le domaine fréquentiel en vue de rendre les traitements compatibles avec les contraintes matérielles de la mise en oeuvre à très haut débit. Le second point étudié concerne les difficultés potentielles de l'utilisation du multiplexage en polarisation. La dernière partie de la thèse traite de l'étude conjointe des fonctions d'égalisation et de synchronisation porteuse et phase pour l'application aux formats de modulation à très grande efficacité spectrale.
Book Synopsis Turbocodes et modulations à grande efficacité spectrale by : Laura Conde Canencia
Download or read book Turbocodes et modulations à grande efficacité spectrale written by Laura Conde Canencia and published by . This book was released on 2004 with total page 138 pages. Available in PDF, EPUB and Kindle. Book excerpt: Cette thèse s'inscrit dans un contexte d'étude de systèmes de communications numériques à la fois limités en spectre et en puissance. L'effort de maximisation de l'efficacité spectrale des transmissions passe alors par l'association de codes correcteurs d'erreurs performants à haut rendement avec des modulations d'ordre élevé. Parmi les codes correcteurs d'erreurs les plus performants, les turbocodes dits duo-binaires présentent des performances de correction supérieures à celles des turbocodes classiques, aussi bien pour les taux d'erreurs élevés que faibles. D'autre part, les modulations turbocodées pragmatiques, associant un turbocode standard avec un codage de Gray des points de la constellation, constituent un schéma à la fois flexible et performant. Une première partie de l'étude est consacrée aux performances des modulations turbocodées pragmatiques à base de codes duo-binaires pour la transmission de blocs courts, aussi bien sur canal gaussien que sur canal à évanouissements de type Rayleigh. La simulation de différentes stratégies de construction des symboles a permis de constater qu'une meilleure convergence du processus itératif est obtenue lorsque les bits systématiques sont affectés aux places binaires les mieux protégées par la modulation. En revanche, pour atteindre les meilleurs gains asymptotiques, la protection des bits de parité est à privilégier. La seconde partie de la thèse est consacrée à l'estimation de la performance à très faible taux d'erreurs des modulations turbocodées. Le point de départ de cette étude est la méthode dite de l'impulsion d'erreur, qui fournit une estimation de la distance minimale du turbocode et de sa multiplicité. Il s'agit d'une méthode basée sur l'aptitude du décodeur à corriger les erreurs de type impulsionnel. L'analyse qui a été développée permet d'utiliser les informations fournies par cette méthode pour estimer les performances à tort rapport signal à bruit des modulations turbocodées pragmatiques lorsqu'un entrelacement des bits codés est mis en œuvre. Sur canal gaussien, deux méthodes d'estimation sont proposées. La première, basée sur la distance libre de la modulation codée, fournit une estimation pessimiste de la performance. La seconde considère les caractéristiques les caractéristiques statistiques de la modulation et permet d'approcher à 0,3 dB les résultats de simulation. Sur canal de Rayleigh, nous avons montré que l'évaluation de bornes des performances est également possible à partir des informations fournies par la méthode de l'impulsion d'erreur. Les estimations ainsi obtenues en quelques secondes permettent de prévoir avec une bonne précision des résultats de simulation requerrant des dizaines d'heures de calcul.
Book Synopsis Digital Signal Processing for Next-Generation Passive Optical Networks by : Tuan Anh Truong
Download or read book Digital Signal Processing for Next-Generation Passive Optical Networks written by Tuan Anh Truong and published by . This book was released on 2014 with total page 181 pages. Available in PDF, EPUB and Kindle. Book excerpt: Cette thèse vise à améliorer l'efficacité spectrale des transmissions sur fibres optiques dans le cadre de réseaux d'accès où une technique de modulation d'intensité et détection directe (IMDD) est utilisée. Dans cette thèse, l'utilisation des techniques de traitement du signal pour compenser des défauts du canal de transmission est analysée. La première partie de cette thèse est dédiée à la modélisation avancée d'une liaison de transmission sur fibres optiques. À la fois l'extraction des paramètres et la validation du modèle sont réalisées avec des mesures expérimentales. Exploitant le modèle du canal, la première étude concerne les techniques d'égalisation de canal pour une transmission classique de type non retour à zéro (NRZ). En outre, la performance du filtre de mise en forme de Nyquist est aussi étudiée. La deuxième étude de cette thèse est consacrée à l'évaluation des performances de la modulation OFDM. En particulier, les systèmes conventionnels de modulation adaptée proposés par Levin-Campello sont soumis à l'étude. En précodant des symboles OFDM par une matrice de la transformation de Fourier discrète (DFT), un système OFDM précodé qui permet de réduire la consommation de puissance du système OFDM est également proposé. Enfin, les techniques conventionnelles et proposées pour compenser des défauts d'une modulation OFDM, y compris l'important PAPR et la sensibilité à la synchronisation temporelle sont étudiées.
Book Synopsis Formats de Modulation Et Traitement Du Signal Avancés Pour Les Communications Optiques Très Hauts Débits À Forte Efficacité Spectrale by : Rafael Rios Müller
Download or read book Formats de Modulation Et Traitement Du Signal Avancés Pour Les Communications Optiques Très Hauts Débits À Forte Efficacité Spectrale written by Rafael Rios Müller and published by . This book was released on 2016 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Coherent detection in combination with digital signal processing is now the de facto standard for long-haul high capacity optical communications systems operating at 100 Gb/s per channel and beyond. With the advent of high-speed high-resolution digital-to-analog converters, generation of high order modulation formats with digital pulse shaping has become possible allowing the increase of system spectral efficiency. Furthermore, the widespread use of transmission links without in-line dispersion compensation enables elegant analytical optical channel modeling which facilitates the use of powerful tools from information theory and digital signal processing. Relying on these aforementioned tools, the introduction of time-interleaved hybrid modulation formats, multi-dimensional modulation formats, and alternative quadrature amplitude modulation formats is investigated in high-speed optical transmission systems. Their impact on signal processing algorithms and achievable information rate over optical links is studied in detail. Next, the design of next generation transponders based on high symbol rate signals operating at 400 Gb/s and 1 Tb/s is investigated. These systems are attractive to reduce the cost per bit as more capacity can be integrated in a single transponder. Thanks to the development of advanced signal processing algorithms combined with state-of-the-art opto-electronic components, record high-capacity transmission experiments are demonstrated: the first single carrier 400 Gb/s transmission over transatlantic distance (at 6 b/s/Hz) and the first 1 Tb/s net data rate transmission based on the parallel synthesis of multiple spectral slices (at 8 b/s/Hz).
Author :North Atlantic Treaty Organization. Advisory Group for Aerospace Research and Development. Sensor and Propagation Panel. Symposium Publisher : ISBN 13 : Total Pages :488 pages Book Rating :4.E/5 ( download)
Book Synopsis Digital Communications Systems by : North Atlantic Treaty Organization. Advisory Group for Aerospace Research and Development. Sensor and Propagation Panel. Symposium
Download or read book Digital Communications Systems written by North Atlantic Treaty Organization. Advisory Group for Aerospace Research and Development. Sensor and Propagation Panel. Symposium and published by . This book was released on 1996 with total page 488 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis General Relativity and Gravitational Waves by : Joseph Weber
Download or read book General Relativity and Gravitational Waves written by Joseph Weber and published by Courier Corporation. This book was released on 2004-01-01 with total page 210 pages. Available in PDF, EPUB and Kindle. Book excerpt: An internationally famous physicist and electrical engineer, the author of this text was a pioneer in the investigation of gravitational waves. Joseph Weber's General Relativity and Gravitational Waves offers a classic treatment of the subject. Appropriate for upper-level undergraduates and graduate students, this text remains ever relevant. Brief but thorough in its introduction to the foundations of general relativity, it also examines the elements of Riemannian geometry and tensor calculus applicable to this field. Approximately a quarter of the contents explores theoretical and experimental aspects of gravitational radiation. The final chapter focuses on selected topics related to general relativity, including the equations of motion, unified field theories, Friedman's solution of the cosmological problem, and the Hamiltonian formulation of general relativity. Exercises. Index.
Book Synopsis Quantum Mechanics, Volume 3 by : Claude Cohen-Tannoudji
Download or read book Quantum Mechanics, Volume 3 written by Claude Cohen-Tannoudji and published by John Wiley & Sons. This book was released on 2019-12-16 with total page 790 pages. Available in PDF, EPUB and Kindle. Book excerpt: This new, third volume of Cohen-Tannoudji's groundbreaking textbook covers advanced topics of quantum mechanics such as uncorrelated and correlated identical particles, the quantum theory of the electromagnetic field, absorption, emission and scattering of photons by atoms, and quantum entanglement. Written in a didactically unrivalled manner, the textbook explains the fundamental concepts in seven chapters which are elaborated in accompanying complements that provide more detailed discussions, examples and applications. * Completing the success story: the third and final volume of the quantum mechanics textbook written by 1997 Nobel laureate Claude Cohen-Tannoudji and his colleagues Bernard Diu and Franck Laloë * As easily comprehensible as possible: all steps of the physical background and its mathematical representation are spelled out explicitly * Comprehensive: in addition to the fundamentals themselves, the books comes with a wealth of elaborately explained examples and applications Claude Cohen-Tannoudji was a researcher at the Kastler-Brossel laboratory of the Ecole Normale Supérieure in Paris where he also studied and received his PhD in 1962. In 1973 he became Professor of atomic and molecular physics at the Collège des France. His main research interests were optical pumping, quantum optics and atom-photon interactions. In 1997, Claude Cohen-Tannoudji, together with Steven Chu and William D. Phillips, was awarded the Nobel Prize in Physics for his research on laser cooling and trapping of neutral atoms. Bernard Diu was Professor at the Denis Diderot University (Paris VII). He was engaged in research at the Laboratory of Theoretical Physics and High Energy where his focus was on strong interactions physics and statistical mechanics. Franck Laloë was a researcher at the Kastler-Brossel laboratory of the Ecole Normale Supérieure in Paris. His first assignment was with the University of Paris VI before he was appointed to the CNRS, the French National Research Center. His research was focused on optical pumping, statistical mechanics of quantum gases, musical acoustics and the foundations of quantum mechanics.
Book Synopsis Experimental Chaos by : Stefano Boccaletti
Download or read book Experimental Chaos written by Stefano Boccaletti and published by A I P Press. This book was released on 2004-12-14 with total page 384 pages. Available in PDF, EPUB and Kindle. Book excerpt: The 8th Experimental Chaos Conference again demonstrated the broad spectrum of areas where nonlinear dynamics plays an important role, such as circuits, hydrodynamics, optics, chemistry, fracture dynamics, neuroscience, and cognitive science. Additional contributions outline the trends for development and application of concepts and techniques of nonlinear dynamics.
Book Synopsis Subcritical Assemblies by : W. Maurice Pritchard
Download or read book Subcritical Assemblies written by W. Maurice Pritchard and published by . This book was released on 1963 with total page 48 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Flow Sensing in Air and Water by : Horst Bleckmann
Download or read book Flow Sensing in Air and Water written by Horst Bleckmann and published by Springer Science & Business Media. This book was released on 2014-01-22 with total page 558 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this book, leading scientists in the fields of sensory biology, neuroscience, physics and engineering explore the basic operational principles and behavioral uses of flow sensing in animals and how they might be applied to engineering applications such as autonomous control of underwater or aerial vehicles. Although humans possess no flow-sensing abilities, countless aquatic (e.g. fish, cephalopods and seals), terrestrial (e.g. crickets and spiders) and aerial (e.g. bats) animals have flow sensing abilities that underlie remarkable behavioral feats. These include the ability to follow silent hydrodynamic trails long after the trailblazer has left the scene, to form hydrodynamic images of their environment in total darkness, and to swim or fly efficiently and effortlessly in the face of destabilizing currents and winds.
Author :North Atlantic Treaty Organization. Advisory Group for Aerospace Research and Development. Aerospace Medical Panel. Symposium Publisher : ISBN 13 : Total Pages :374 pages Book Rating :4.E/5 ( download)
Book Synopsis Audio Effectiveness in Aviation by : North Atlantic Treaty Organization. Advisory Group for Aerospace Research and Development. Aerospace Medical Panel. Symposium
Download or read book Audio Effectiveness in Aviation written by North Atlantic Treaty Organization. Advisory Group for Aerospace Research and Development. Aerospace Medical Panel. Symposium and published by . This book was released on 1997 with total page 374 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Optical Microresonators by : John Heebner
Download or read book Optical Microresonators written by John Heebner and published by Springer Science & Business Media. This book was released on 2008 with total page 275 pages. Available in PDF, EPUB and Kindle. Book excerpt: Optical Micro-Resonators are an exciting new field of research that has gained prominence in the past few years due to the emergence of new fabrication technologies. This book is the first detailed text on the theory, fabrication, and applications of optical micro-resonators, and will be found useful by both graduate students and researchers in the field.
Book Synopsis The X-ray Universe by : Wallace H. Tucker
Download or read book The X-ray Universe written by Wallace H. Tucker and published by . This book was released on 1985 with total page 230 pages. Available in PDF, EPUB and Kindle. Book excerpt: Beyond the range of optical perception--and of ordinary imaginings--a new and violent universe lay undetected until the advent of space exploration. Supernovae, black holes, quasars and pulsars--these were the secrets of the highenergy world revealed when, for the first time, astronomers attached their instruments to rockets and lofted them beyond the earth's x-ray-absorbing atmosphere. The X-Ray Universe is the story of these explorations and the fantastic new science they brought into being. It is a first-hand account: Riccardo Giacconi is one of the principal pioneers of the field, and Wallace Tucker is a theorist who worked closely with him at many critical periods. The book carries the reader from the early days of the Naval Research Laboratory through the era of V-2 rocketry, Sputnik, and the birth of NASA, to the launching of the Einstein X-Ray Observatory. But this is by no means just a history. Behind the suspenseful, sometimes humorous details of human personality grappling with high technology lies a sophisticated exposition of current cosmology and astrophysics, from the rise and fall of the steady-state theory to the search for the missing mass of the universe.
Book Synopsis Organic Solid-State Lasers by : Sébastien Forget
Download or read book Organic Solid-State Lasers written by Sébastien Forget and published by Springer. This book was released on 2013-07-03 with total page 179 pages. Available in PDF, EPUB and Kindle. Book excerpt: Organic lasers are broadly tunable coherent sources, potentially compact, convenient and manufactured at low-costs. Appeared in the mid 60’s as solid-state alternatives for liquid dye lasers, they recently gained a new dimension after the demonstration of organic semiconductor lasers in the 90's. More recently, new perspectives appeared at the nanoscale, with organic polariton and surface plasmon lasers. After a brief reminder to laser physics, a first chapter exposes what makes organic solid-state organic lasers specific. The laser architectures used in organic lasers are then reviewed, with a state-of-the-art review of the performances of devices with regard to output power, threshold, lifetime, beam quality etc. A survey of the recent trends in the field is given, highlighting the latest developments with a special focus on the challenges remaining for achieving direct electrical pumping of organic semiconductor lasers. A last chapter covers the applications of organic solid-state lasers.
Book Synopsis Routledge International Handbook of Ignorance Studies by : Matthias Gross
Download or read book Routledge International Handbook of Ignorance Studies written by Matthias Gross and published by Routledge. This book was released on 2015-05-15 with total page 427 pages. Available in PDF, EPUB and Kindle. Book excerpt: Once treated as the absence of knowledge, ignorance today has become a highly influential topic in its own right, commanding growing attention across the natural and social sciences where a wide range of scholars have begun to explore the social life and political issues involved in the distribution and strategic use of not knowing. The field is growing fast and this handbook reflects this interdisciplinary field of study by drawing contributions from economics, sociology, history, philosophy, cultural studies, anthropology, feminist studies, and related fields in order to serve as a seminal guide to the political, legal and social uses of ignorance in social and political life. Chapter 33 of this book is freely available as a downloadable Open Access PDF under a Creative Commons Attribution-Non Commercial-No Derivatives 4.0 license available here: https://tandfbis.s3-us-west-2.amazonaws.com/rt-files/docs/Open+Access+Chapters/9780415718967_oachapter33.pdf
