Download or read book Applications du codage spatio temporel des r seaux sans fils written by Elie Jandot Dit Danjou and published by . This book was released on 2006 with total page 170 pages. Available in PDF, EPUB and Kindle. Book excerpt: Les systèmes de transmission non filaire sont trés populaires et se développent rapidement. La demande est trés forte pour augmenter les débits ainsi que la qualité des liaisons alors que le maillage des réseaux se densifie. Dans ce contexte où les ressources spectrales sont limitées, les codes espace-temps (ST) offrent de grandes possibilités d'évolution. Le codage ST permet d'augmenter le débit de transmission au niveau de la couche physique tout en relâchant les contraintes sur le compromis entre la puissance d'émission et le taux d'erreur de décodage. Dans la première partie de cette thèse, des techniques de codage et de décodage ST cohérents ont été appliquées à des réseaux locaux sans fils de type WIFI. Un démonstrateur MIMO 2x2 sur FPGA a été réalisé à partir de la norme IEEE 802.11A. La seconde partie traite du codage ST non cohérent, où les coefficients du canal sont inconnus au niveau de l'émetteur comme au niveau du récepteur. Une nouvelle famille de codes ST non cohérents utilisant les modulations de fréquence est proposée . Cette solution multi-antennaire permet, par exemple, d'améliorer sensiblement les performances des systèmes bluetooth.

Download or read book Codage spatio temporel et gain de multiplexage multi utilisateurs pour les canaux s lectifs written by Lina Mroueh and published by . This book was released on 2010 with total page 143 pages. Available in PDF, EPUB and Kindle. Book excerpt: Les nouvelles générations de réseaux sans fils tels que IEEE 802.11n, IEEE 802.16m, LTE advanced, etc sont basées sur des techniques de transmission multi-antennes et multi-utilisateurs. Dans les systèmes de communications point à point, l'utilisation de plusieurs antennes l'émission et à la réception permet non seulement d'augmenter le débit transmis, mais aussi de garantir une meilleure qualité du signal reçu. Dans cette thèse, on propose une nouvelle famille des codes spatio-temporels pour les canaux sélectifs et nous montrons comment les codes dérivés de l'algèbre de division cyclique peuvent être appliqués dans un système réel, et nous nous focalisons sur leur optimalité et les limites pratiques qui peuvent être rencontrées en industrie. Dans le contexte multi-utilisateurs, l'exploitation du gain de multiplexage multi-utilisateurs permet d'augmenter considérablement le débit global du réseau. Dans le cadre de cette thèse, deux systèmes multiutilisateurs ont été étudiés dans le cas où les canaux entre la source et la destination possèdent une mémoire en temps et en fréquence. Pour le canal sélectif à interférence, on montre que le gain de multiplexage maximal peut être atteint en utilisant un système à alignement d'interférence sous certaines conditions de propagation de canal. Pour le canal sélectif à diffusion, on prouve que le gain multiutilsateur de multiplexage peut être conservé en utilisant une connaissance partielle du canal et un nombre de bits réduits qu'on calcule.

Download or read book INTRODUCTION D UN CODAGE SPATIO TEMPOREL DANS LES ARCHITECTURES CLASSIQUES DE RESEAUX DE NEURONES ARTIFICIELS APPLICATION A LA RECONNAISSANCE DE CARACTERES MANUSCRITS written by NASSER.. MOZAYYANI and published by . This book was released on 1998 with total page 171 pages. Available in PDF, EPUB and Kindle. Book excerpt: DE NOS JOURS, IL EXISTE DIVERSES APPLICATIONS INDUSTRIELLES NECESSITANT LE TRAITEMENT DE FORMES SPATIO-TEMPORELLES (ST). IL S'AGIT DE DONNEES MULTI-DIMENSIONNELLES A LA FOIS CORRELEES DANS L'ESPACE ET DANS LE TEMPS, COMME PAR EXEMPLE UNE SEQUENCE ANIMEE D'IMAGES. LES MODELES CONNEXIONNISTES, SURTOUT CONNUS POUR LEUR CAPACITE A EXTRAIRE DES CORRELATIONS SPATIALES, COMMENCENT A PROPOSER DES SOLUTIONS POUR TRAITER DES FORMES ST. CE TRAVAIL PROPOSE D'ELARGIR LES CAPACITES DE PLUSIEURS MODELES DE RESEAUX DE NEURONES ARTIFICIELS (RNA) CONNUS AU TRAITEMENT DES FORMES ST COMPOSEES DE SIGNAUX IMPULSIONNELS. NOTRE APPROCHE REPOSE SUR UN CODAGE INTEGRANT LES CARACTERISTIQUES SPATIALES ET TEMPORELLES DES DONNEES. CE CODAGE EST DEFINI DANS LE CORPS DES COMPLEXES. L'UN DES DEUX DEGRES DE LIBERTE DE CES NOMBRES CODE L'AMPLITUDE DES IMPULSIONS, L'AUTRE EST CONSACRE A LA DATE DE CES IMPULSIONS. NOUS AVONS VALIDE NOTRE APPROCHE SUR LE PERCEPTRON MULTICOUCHE, LA CARTE DE KOHONEN ET LE RESEAU RBF. NOUS AVONS PAR AILLEURS TENTE D'INTEGRER NOTER CODAGE DANS LE MODELE DE HOPFIELD ET CONSTATE QUE LA DEMARCHE PRESENTE DANS CE CAS PEU D'INTERET. POUR ALLER AU DELA DE QUELQUES EXEMPLES ILLUSTRATIFS, LA DERNIERE PARTIE DE LA THESE EST CONSACREE A UNE APPLICATION CONCRETE DANS LE DOMAINE DE LA RECONNAISSANCE EN LIGNE DE CARACTERES MANUSCRITS ISOLES. LE TRACE D'UN CARACTERE PRODUIT, EN EFFET, DES INFORMATIONS DE NATURE ST PRENANT EN COMPTE A LA FOIS LA DISPOSITION DES POINTS ET LEUR ORDONNANCEMENT DANS LE TEMPS. NOUS PROPOSONS UN SYSTEME DE RECONNAISSANCE A DEUX ETAGES CONNEXIONNISTES : LE PREMIER IDENTIFIE CERTAINES PRIMITIVES DANS LE TRACE DES LETTRES ET LE DEUXIEME EFFECTUE LA TACHE DE RECONNAISSANCE. CE SYSTEME, DONT LES PERFORMANCES SUR DES BASES MULTISCRIPTEURS SONT PROMETTEUSES, PRESENTE L'AVANTAGE D'ETRE BEAUCOUP PLUS SIMPLE QUE CEUX EXISTANT PAR AILLEURS.

Download or read book Annales des t l communications written by and published by . This book was released on 2003-12 with total page 752 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Network Coding Applications written by Christina Fragouli and published by Now Publishers Inc. This book was released on 2008-01-08 with total page 150 pages. Available in PDF, EPUB and Kindle. Book excerpt: Network Coding Applications looks at how ideas from network coding can have an impact on a number of new applications. It explains what network coding is, explores what its benefits are, and how much it costs to design and operate networks implementing network coding

Download or read book 3G Evolution written by Erik Dahlman and published by Academic Press. This book was released on 2007 with total page 448 pages. Available in PDF, EPUB and Kindle. Book excerpt: This practical book, written by engineers working closely in 3GPP, gives insight into the new technologies adopted by 3GPP, with detailed explanations of the specific solutions chosen and their implementation in HSPA and LTE. The key technologies presented include multi-carrier transmission, advanced single-carrier transmission, advanced receivers, OFDM, MIMO and adaptive antenna solutions, advanced radio resource management and protocols, and different radio network architectures. Their role and use in the context of mobile broadband access in general is explained. Both a high-level overview and more detailed step-by-step explanations of HSPA and LTE implementation are given. An overview of other related systems such as TD SCDMA, CDMA2000, and WIMAX is also provided.This is a ‘must-have’ resource for engineers and other professionals working with cellular or wireless broadband technologies who need to know how to utilize the new technology to stay ahead of the competition. Gives the first explanation of the radio access technologies and key international standards for moving to the next stage of 3G evolution- fully operational mobile broadband Describes the new technologies selected by the 3GPP to realise High Speed Packet Access (HSPA) and Long Term Evolution (LTE) for mobile broadband Gives both higher-level overviews and detailed explanations of HSPA and LTE as specified by 3GPP

Download or read book Network Coding written by Muriel Medard and published by Academic Press. This book was released on 2012 with total page 353 pages. Available in PDF, EPUB and Kindle. Book excerpt: Introduction -- Network coding Fundamentals -- Harnessing Network Coding in Wireless Systems -- Network Coding for Content Distribution and Multimedia Streaming in Peer-to-Peer Networks -- Network Coding in the Real World -- Network Coding and User Cooperation for Streaming and Download Services in LTE Networks -- CONCERTO: Experiences with a Real-World MANET System Based on Network Coding -- Secure Network Coding: Bounds and Algorithms for Secret and Reliable Communications -- Network Coding and Data Compression -- Scaling Laws with Network Coding -- Network Coding in Disruption Tolerant Networks.

Download or read book Network Coding Theory written by Raymond W. Yeung and published by Now Publishers Inc. This book was released on 2006 with total page 156 pages. Available in PDF, EPUB and Kindle. Book excerpt: Provides a tutorial on the basics of network coding theory. Divided into two parts, this book presents a unified framework for understanding the basic notions and fundamental results in network coding. It is aimed at students, researchers and practitioners working in networking research.

Download or read book Terra 2008 written by Leslie Rainer and published by Getty Publications. This book was released on 2011-06-14 with total page 438 pages. Available in PDF, EPUB and Kindle. Book excerpt: Earthen architecture constitutes one of the most diverse forms of cultural heritage and one of the most challenging to preserve. It dates from all periods and is found on all continents but is particularly prevalent in Africa, where it has been a building tradition for centuries. Sites range from ancestral cities in Mali to the palaces of Abomey in Benin, from monuments and mosques in Iran and Buddhist temples on the Silk Road to Spanish missions in California. This volume's sixty-four papers address such themes as earthen architecture in Mali, the conservation of living sites, local knowledge systems and intangible aspects, seismic and other natural forces, the conservation and management of archaeological sites, research advances, and training.

Download or read book Information Theory and Network Coding written by Raymond W. Yeung and published by Springer Science & Business Media. This book was released on 2008-09-10 with total page 592 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book is an evolution from my book A First Course in Information Theory published in 2002 when network coding was still at its infancy. The last few years have witnessed the rapid development of network coding into a research ?eld of its own in information science. With its root in infor- tion theory, network coding has not only brought about a paradigm shift in network communications at large, but also had signi?cant in?uence on such speci?c research ?elds as coding theory, networking, switching, wireless c- munications,distributeddatastorage,cryptography,andoptimizationtheory. While new applications of network coding keep emerging, the fundamental - sults that lay the foundation of the subject are more or less mature. One of the main goals of this book therefore is to present these results in a unifying and coherent manner. While the previous book focused only on information theory for discrete random variables, the current book contains two new chapters on information theory for continuous random variables, namely the chapter on di?erential entropy and the chapter on continuous-valued channels. With these topics included, the book becomes more comprehensive and is more suitable to be used as a textbook for a course in an electrical engineering department.

Download or read book MILCOM 2005 written by Institute of Electrical and Electronics Engineers and published by . This book was released on 2005 with total page 674 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Transport urbain dans les pays en d veloppement written by and published by . This book was released on 1990 with total page 1108 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Divine Names on the Spot written by Fabio Porzia and published by . This book was released on 2023 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: 'Ancient Greek and Semitic languages resorted to a large range of words to name the divine. Gods and goddesses were called by a variety of names and combinations of onomastic attributes. This broad lexicon of names is characterised by plurality and a tendency to build on different sequences of names; therefore, the Mapping Ancient Polytheisms project focuses on the process of naming the divine in order to better understand the ancient divine in terms of a plurality in the making. A fundamental rule for reading ancient divine names is to grasp them in their context - time and place, a ritual, the form of the discourse, a cultural milieu...: a deity is usually named according to a specific situation. From Artemis Eulochia to al-Lat, al-'Uzza and Manat, from Melqart to "my rock" in the biblical book of Psalms, this volume journeys between the sanctuary on Mount Gerizim and late antique magical practices, revisiting rituals, hymnic poetry, oaths of orators and philosophical prayers. While targeting different names in different contexts, the contributors draft theoretical propositions towards a dynamic approach of naming the divine in antiquity.'

Download or read book Advanced Intelligent Systems for Sustainable Development AI2SD 2020 written by Janusz Kacprzyk and published by Springer Nature. This book was released on 2022-02-10 with total page 1298 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book publishes the best papers accepted and presented at the 3rd edition of the International Conference on Advanced Intelligent Systems for Sustainable Development Applied to Agriculture, Energy, Health, Environment, Industry, Education, Economy, and Security (AI2SD’2020). This conference is one of the biggest amalgamations of eminent researchers, students, and delegates from both academia and industry where the collaborators have an interactive access to emerging technology and approaches globally. In this book, readers find the latest ideas addressing technological issues relevant to all areas of the social and human sciences for sustainable development. Due to the nature of the conference with its focus on innovative ideas and developments, the book provides the ideal scientific and brings together very high-quality chapters written by eminent researchers from different disciplines, to discover the most recent developments in scientific research.

Download or read book Network Coding written by Tracey Ho and published by Cambridge University Press. This book was released on 2008-04-14 with total page 184 pages. Available in PDF, EPUB and Kindle. Book excerpt: Network coding promises to significantly impact the way communications networks are designed, operated, and understood. The first book to present a unified and intuitive overview of the theory, applications, challenges, and future directions of this emerging field, this is a must-have resource for those working in wireline or wireless networking. *Uses an engineering approach - explains the ideas and practical techniques *Covers mathematical underpinnings, practical algorithms, code selection, security, and network management *Discusses key topics of inter-session (non-multicast) network coding, lossy networks, lossless networks, and subgraph-selection algorithms Starting with basic concepts, models, and theory, then covering a core subset of results with full proofs, Ho and Lun provide an authoritative introduction to network coding that supplies both the background to support research and the practical considerations for designing coded networks. This is an essential resource for graduate students and researchers in electronic and computer engineering and for practitioners in the communications industry.

Download or read book Communicating Pictures written by David Bull and published by Academic Press. This book was released on 2014-07-19 with total page 561 pages. Available in PDF, EPUB and Kindle. Book excerpt: Communicating Pictures starts with a unique historical perspective of the role of images in communications and then builds on this to explain the applications and requirements of a modern video coding system. It draws on the author's extensive academic and professional experience of signal processing and video coding to deliver a text that is algorithmically rigorous, yet accessible, relevant to modern standards, and practical. It offers a thorough grounding in visual perception, and demonstrates how modern image and video compression methods can be designed in order to meet the rate-quality performance levels demanded by today's applications, networks and users.With this book you will learn: - Practical issues when implementing a codec, such as picture boundary extension and complexity reduction, with particular emphasis on efficient algorithms for transforms, motion estimators and error resilience - Conflicts between conventional video compression, based on variable length coding and spatiotemporal prediction, and the requirements for error resilient transmission - How to assess the quality of coded images and video content, both through subjective trials and by using perceptually optimised objective metrics - Features, operation and performance of the state-of-the-art High Efficiency Video Coding (HEVC) standard - Covers the basics of video communications and includes a strong grounding in how we perceive images and video, and how we can exploit redundancy to reduce bitrate and improve rate distortion performance - Gives deep insight into the pitfalls associated with the transmission of real-time video over networks (wireless and fixed) - Uses the state-of- the-art video coding standard (H.264/AVC) as a basis for algorithm development in the context of block based compression - Insight into future video coding standards such as the new ISO/ITU High Efficiency Video Coding (HEVC) initiative, which extends and generalizes the H.264/AVC approach

Download or read book Interpreting Archaeological Topography written by David Cowley and published by Oxbow Books Limited. This book was released on 2013 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Airborne Laser Scanning (ALS), or lidar, is an enormously important innovation for data collection and interpretation in archaeology. The application of archaeological 3D data deriving from sources including ALS, close-range photogrammetry and terrestrial and photogrammetric scanners has grown exponentially over the last decade. Such data present numerous possibilities and challenges, from ensuring that applications remain archaeologically relevant, to developing practices that integrate the manipulation and interrogation of complex digital datasets with the skills of archaeological observation and interpretation. This volume addresses the implications of multi-scaled topographic data for contemporary archaeological practice in a rapidly developing field, drawing on examples of ongoing projects and reflections on best practice. Twenty papers from across Europe explore the implications of these digital 3D datasets for the recording and interpretation of archaeological topography, whether at the landscape, site or artifact scale. The papers illustrate the variety of ways in which we engage with archaeological topography through 3D data, from discussions of its role in landscape archaeology, to issues of context and integration, and to the methodological challenges of processing, visualization and manipulation. Critical reflection on developing practice and implications for cultural resource management and research contextualize the case studies and applications, illustrating the diverse and evolving roles played by multi-scalar topographic data in contemporary archaeology.