Accès multiple OFDMA pour les systèmes cellulaires post 3G

Accès multiple OFDMA pour les systèmes cellulaires post 3G PDF Author: Carle Lengoumbi Makogha
Publisher:
ISBN:
Category :
Languages : fr
Pages : 197

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Book Description
Cette thèse s'intéresse à l'allocation de ressources des réseaux WMAN (Wireless Metropolitan Area Networks) utilisant l'OFDMA (Orthogonal Frequency Division Multiple Access). Les applications récentes destinées aux réseaux sans fils requièrent des débits importants. L'OFDMA, technique d'accès multiple basée sur l'OFDM (Orthogonal Frequency Division Multiplexing), permet d'obtenir des débits élevés grâce à la diversité multiutilisateur. Dans une première partie, l'allocation de ressources est considérée au niveau de la couche physique (affectation des fréquences et de la puissance). Dans un contexte monocellulaire, un algorithme est proposé afin de maximiser le débit de la cellule tout en assurant des débits individuels aux utilisateurs (Rate-Adaptive Optimization). L'impact de la sous-canalisation sur le débit global est analysé. Puis, un algorithme est proposé dans un contexte multicellulaire pour adapter dynamiquement le facteur de réutilisation fréquentiel. Dans une deuxième partie, l'ordonnancement est traité. L'objectif est de garantir les délais du trafic en temps réel, de maximiser le débit du trafic non temps réel tout en assurant une équité proportionnelle entre les flux. Pour cela, les extensions du GPS ( Global Processor Sharing) sont étudiées. Deux algorithmes, extensions du WFS (Wireless Fair Service) pour l'OFDMA, sont proposés. Leurs performances sont comparées au WFS et aux algorithmes existants en OFDMA. Une des propositions, l'OWFS (Opportunist WFS) est particulièrement adaptée pour maximiser le débit du trafic non temps réel et comporte un paramètre, le poids de délai, qui permet de maintenir un taux de pertes acceptable pour le trafic temps réel.

Accès multiple OFDMA pour les systèmes cellulaires post 3G

Accès multiple OFDMA pour les systèmes cellulaires post 3G PDF Author: Carle Lengoumbi Makogha
Publisher:
ISBN:
Category :
Languages : fr
Pages : 197

Get Book Here

Book Description
Cette thèse s'intéresse à l'allocation de ressources des réseaux WMAN (Wireless Metropolitan Area Networks) utilisant l'OFDMA (Orthogonal Frequency Division Multiple Access). Les applications récentes destinées aux réseaux sans fils requièrent des débits importants. L'OFDMA, technique d'accès multiple basée sur l'OFDM (Orthogonal Frequency Division Multiplexing), permet d'obtenir des débits élevés grâce à la diversité multiutilisateur. Dans une première partie, l'allocation de ressources est considérée au niveau de la couche physique (affectation des fréquences et de la puissance). Dans un contexte monocellulaire, un algorithme est proposé afin de maximiser le débit de la cellule tout en assurant des débits individuels aux utilisateurs (Rate-Adaptive Optimization). L'impact de la sous-canalisation sur le débit global est analysé. Puis, un algorithme est proposé dans un contexte multicellulaire pour adapter dynamiquement le facteur de réutilisation fréquentiel. Dans une deuxième partie, l'ordonnancement est traité. L'objectif est de garantir les délais du trafic en temps réel, de maximiser le débit du trafic non temps réel tout en assurant une équité proportionnelle entre les flux. Pour cela, les extensions du GPS ( Global Processor Sharing) sont étudiées. Deux algorithmes, extensions du WFS (Wireless Fair Service) pour l'OFDMA, sont proposés. Leurs performances sont comparées au WFS et aux algorithmes existants en OFDMA. Une des propositions, l'OWFS (Opportunist WFS) est particulièrement adaptée pour maximiser le débit du trafic non temps réel et comporte un paramètre, le poids de délai, qui permet de maintenir un taux de pertes acceptable pour le trafic temps réel.

Technological Developments in Networking, Education and Automation

Technological Developments in Networking, Education and Automation PDF Author: Khaled Elleithy
Publisher: Springer Science & Business Media
ISBN: 9048191513
Category : Technology & Engineering
Languages : en
Pages : 623

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Book Description
Technological Developments in Networking, Education and Automation includes a set of rigorously reviewed world-class manuscripts addressing and detailing state-of-the-art research projects in the following areas: Computer Networks: Access Technologies, Medium Access Control, Network architectures and Equipment, Optical Networks and Switching, Telecommunication Technology, and Ultra Wideband Communications. Engineering Education and Online Learning: including development of courses and systems for engineering, technical and liberal studies programs; online laboratories; intelligent testing using fuzzy logic; taxonomy of e-courses; and evaluation of online courses. Pedagogy: including benchmarking; group-learning; active learning; teaching of multiple subjects together; ontology; and knowledge management. Instruction Technology: including internet textbooks; virtual reality labs, instructional design, virtual models, pedagogy-oriented markup languages; graphic design possibilities; open source classroom management software; automatic email response systems; tablet-pcs; personalization using web mining technology; intelligent digital chalkboards; virtual room concepts for cooperative scientific work; and network technologies, management, and architecture. Coding and Modulation: Modeling and Simulation, OFDM technology , Space-time Coding, Spread Spectrum and CDMA Systems. Wireless technologies: Bluetooth , Cellular Wireless Networks, Cordless Systems and Wireless Local Loop, HIPERLAN, IEEE 802.11, Mobile Network Layer, Mobile Transport Layer, and Spread Spectrum. Network Security and applications: Authentication Applications, Block Ciphers Design Principles, Block Ciphers Modes of Operation, Electronic Mail Security, Encryption & Message Confidentiality, Firewalls, IP Security, Key Cryptography & Message Authentication, and Web Security. Robotics, Control Systems and Automation: Distributed Control Systems, Automation, Expert Systems, Robotics, Factory Automation, Intelligent Control Systems, Man Machine Interaction, Manufacturing Information System, Motion Control, and Process Automation. Vision Systems: for human action sensing, face recognition, and image processing algorithms for smoothing of high speed motion. Electronics and Power Systems: Actuators, Electro-Mechanical Systems, High Frequency Converters, Industrial Electronics, Motors and Drives, Power Converters, Power Devices and Components, and Power Electronics.

3G Evolution

3G Evolution PDF Author: Erik Dahlman
Publisher: Academic Press
ISBN: 9780123725332
Category : Technology & Engineering
Languages : en
Pages : 448

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Book Description
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

Evolved Cellular Network Planning and Optimization for UMTS and LTE

Evolved Cellular Network Planning and Optimization for UMTS and LTE PDF Author: Lingyang Song
Publisher: CRC Press
ISBN: 1439806500
Category : Computers
Languages : en
Pages : 622

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Book Description
Most books on network planning and optimization provide limited coverage of either GSM or WCDMA techniques. Few scrape the surface of HSPA, and even fewer deal with TD-SCDMA. Filling this void, Evolved Cellular Network Planning and Optimization for UMTS and LTE presents an accessible introduction to all stages of planning and optimizing UMTS, HSPA,

5G: 2020 and Beyond

5G: 2020 and Beyond PDF Author: Ramjee Prasad
Publisher: CRC Press
ISBN: 1000793311
Category : Technology & Engineering
Languages : en
Pages : 125

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Book Description
The future society would be ushered in a new communication era with the emergence of 5G. 5G would be significantly different, especially, in terms of architecture and operation in comparison with the previous communication generations (4G, 3G...). This book discusses the various aspects of the architecture, operation, possible challenges, and mechanisms to overcome them. Further, it supports users? interac- tion through communication devices relying on Human Bond Communication and COmmunication-NAvigation- SENsing- SErvices (CONASENSE).Topics broadly covered in this book are; • Wireless Innovative System for Dynamically Operating Mega Communications (WISDOM)• Millimeter Waves and Spectrum Management• Cyber Security• Device to Device Communication

Quantum Communications and Cryptography

Quantum Communications and Cryptography PDF Author: Alexander V. Sergienko
Publisher: CRC Press
ISBN: 1420026607
Category : Science
Languages : en
Pages : 248

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Book Description
All current methods of secure communication such as public-key cryptography can eventually be broken by faster computing. At the interface of physics and computer science lies a powerful solution for secure communications: quantum cryptography. Because eavesdropping changes the physical nature of the information, users in a quantum exchange can easily detect eavesdroppers. This allows for totally secure random key distribution, a central requirement for use of the one-time pad. Since the one-time pad is theoretically proven to be undecipherable, quantum cryptography is the key to perfect secrecy. Quantum Communications and Cryptography is the first comprehensive review of the past, present, and potential developments in this dynamic field. Leading expert contributors from around the world discuss the scientific foundations, experimental and theoretical developments, and cutting-edge technical and engineering advances in quantum communications and cryptography. The book describes the engineering principles and practical implementations in a real-world metropolitan network as well as physical principles and experimental results of such technologies as entanglement swapping and quantum teleportation. It also offers the first detailed treatment of quantum information processing with continuous variables. Technologies include both free-space and fiber-based communications systems along with the necessary protocols and information processing approaches. Bridging the gap between physics and engineering, Quantum Communications and Cryptography supplies a springboard for further developments and breakthroughs in this rapidly growing area.

Ultra Wide Band Antennas

Ultra Wide Band Antennas PDF Author: Xavier Begaud
Publisher: John Wiley & Sons
ISBN: 1118586573
Category : Technology & Engineering
Languages : en
Pages : 217

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Book Description
Ultra Wide Band Technology (UWB) has reached a level of maturity that allows us to offer wireless links with either high or low data rates. These wireless links are frequently associated with a location capability for which ultimate accuracy varies with the inverse of the frequency bandwidth. Using time or frequency domain waveforms, they are currently the subject of international standards facilitating their commercial implementation. Drawing up a complete state of the art, Ultra Wide Band Antennas is aimed at students, engineers and researchers and presents a summary of internationally recognized studies.

MIMO

MIMO PDF Author: Alain Sibille
Publisher: Academic Press
ISBN: 0123821959
Category : Technology & Engineering
Languages : es
Pages : 385

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Book Description
Foreword from Arogyaswami Paulraj, Professor (Emeritus), Stanford University (USA) - The first book to show how MIMO principles can be implemented in today's mobile broadband networks and components - Explains and solves some of the practical difficulties that arise in designing and implementing MIMO systems - Both theory and implementation sections are written in the context of the most recent standards: IEEE 802.11n (WiFi); IEEE 802.16 (WIMAX); 4G networks (3GPP/3GPP2, LTE)

LTE for 4G Mobile Broadband

LTE for 4G Mobile Broadband PDF Author: Farooq Khan
Publisher: Cambridge University Press
ISBN: 0521882214
Category : Computers
Languages : en
Pages : 507

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Book Description
Understand the new technologies of the LTE standard and their impact on system performance improvements with this practical guide.

Evolution of Air Interface Towards 5G

Evolution of Air Interface Towards 5G PDF Author: Suvra Sekhar Das
Publisher: CRC Press
ISBN: 1000794709
Category : Technology & Engineering
Languages : en
Pages : 296

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Book Description
Over the past few decades, wireless access networks have evolved extensively to support the tremendous growth of consumer traffic. This superlative growth of data consumption has come about due to several reasons, such as evolution of the consumer devices, the types of telephone and smartphone being used, convergence of services, digitisation of economic transactions, tele-education, telemedicine, m-commerce, virtual reality office, social media, e-governance, e-security, to name but a few.Not only has the society transformed to a digital world, but also the expectations from the services provided have increased many folds. The last mile/meters of delivery of all e-services is now required to be wireless. It has always been known that wireless links are the bottleneck to providing high data rates and high quality of service. Several wireless signalling and performance analysis techniques to overcome the hurdles of wireless channels have been developed over the last decade, and these are fuelling the evolution of 4G towards 5G. Evolution of Air Interface Towards 5G attempts to bring out some of the important developments that are contributing towards such growth.