Theartofcomputationofelectromagnetic(EM)problemshasgrownexponentially for three decades due to the availability of powerful computer resources. In spite of this, the EM community has suffered without a suitable text on the computational techniques commonly used in solving EM-related problems. Although there have been monographs on one particular technique or another, the monographs are written for the experts rather than students. Only a few texts cover the major techniques and dothatinamannersuitableforclassroomuse.Itseemsexpertsinthisareaarefamiliar with one or a few techniques but not many seem to be familiar with all the common techniques. This text attempts to fill that gap.
标签： Electromagnetics Techniques Numerical in
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Rapid growth of wireless communication services in recent decades has created a huge demand of radio spectrum. Spectrum scarcity and utilization inefficiency limit the development of wireless networks. Cognitive radio is a promising tech- nology that allows secondary users to reuse the underutilized licensed spectrum of primary users. The major challenge for spectrum sharing is to achieve high spectrum efficiency while making non-intrusive access to the licensed bands. This requires in- formation of availability and quality of channel resources at secondary transmitters, however, is difficult to be obtained perfectly in practice.
标签： Opportunistic Spectrum Sharing
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Optical wireless communication is an emerging and dynamic research and development area that has generated a vast number of interesting solutions to very complicated communication challenges. For example, high data rate, high capacity and minimum interference links for short-range communication for inter-building communication, computer-to-computer communication, or sensor networks. At the opposite extreme is a long-range link in the order of millions of kilometers in the new mission to Mars and other solar system planets.
标签： Communication Wireless Optical Systems
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Recent decades have shown a tremendous expansion of the Internet. The number of connected terminals has increased by orders of magnitude, traffic has grown exponen- tially, coverage has become ubiquitous and worldwide, and today’s sophisticated Web 2.0 applications are increasingly providing services which hitherto have been the realm of telecommunications, such as Skype and video conferencing. This has even led to the thought that access to the Internet might one day be a universal right of every citizen. This evolution will accelerate in the coming decades.
标签： Networking Personal Networks Wireless
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The ever-increasing demand for private and sensitive data transmission over wireless net- works has made security a crucial concern in the current and future large-scale, dynamic, and heterogeneous wireless communication systems. To address this challenge, computer scientists and engineers have tried hard to continuously come up with improved crypto- graphic algorithms. But typically we do not need to wait too long to find an efficient way to crack these algorithms. With the rapid progress of computational devices, the current cryptographic methods are already becoming more unreliable. In recent years, wireless re- searchers have sought a new security paradigm termed physical layer security. Unlike the traditional cryptographic approach which ignores the effect of the wireless medium, physi- cal layer security exploits the important characteristics of wireless channel, such as fading, interference, and noise, for improving the communication security against eavesdropping attacks. This new security paradigm is expected to complement and significantly increase the overall communication security of future wireless networks.
标签： Communications Physical Security Wireless Layer in
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The purpose of this book is to introduce the concept of the Multiple Input Multiple Output (MIMO) radio channel, which is an intelligent communication method based upon using multiple antennas. The book opens by explaining MIMO in layman’s terms to help stu- dents and people in industry working in related areas become easily familiarised with the concept. Therefore the structure of the book will be carefully arranged to allow a user to progress steadily through the chapters and understand the fundamental and mathematical principles behind MIMO through the visual and explanatory way in which they will be written. It is the intention that several references will also be provided, leading to further reading in this highly researched technology.
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The goal of this book is to provide a concise but lucid explanation and deriva- tion of the fundamentals of spread-spectrum communication systems. Although spread-spectrum communication is a staple topic in textbooks on digital com- munication, its treatment is usually cursory, and the subject warrants a more intensive exposition. Originally adopted in military networks as a means of ensuring secure communication when confronted with the threats of jamming and interception, spread-spectrum systems are now the core of commercial ap- plications such as mobile cellular and satellite communication.
标签： Principles Spectrum Spread of
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The continuing vitality of spread-spectrum communication systems and the devel- opment of new mathematical methods for their analysis provided the motivation to undertake this new edition of the book. This edition is intended to enable readers to understand the current state-of-the-art in this field. Almost twenty percent of the materialinthiseditionisnew, includingseveralnewsections, anewchapteronadap- tive arrays and filters, and a new chapter on code-division multiple-access networks.
标签： Spread-Spectrum Communication Principles of
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This book is a result of the recent rapid advances in two related technologies: com- munications and computers. Over the past few decades, communication systems have increased in complexity to the point where system design and performance analysis can no longer be conducted without a significant level of computer sup- port. Many of the communication systems of fifty years ago were either power or noise limited. A significant degrading effect in many of these systems was thermal noise, which was modeled using the additive Gaussian noise channel.
标签： Communication Principles Simulation Systems of
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Communication protocols – for short protocols – form the basis for the opera- tion of computer networks and telecommunication systems. They are behavior conventions which describe how communication systems interact with each other in computer networks. Protocols define the temporal order of the interactions and the formats of the data units exchanged. Communication protocols comprise a wide range of different functions and mechanisms, such as the sending and receiv- ing of data units, their coding/decoding, error control mechanisms, timer control, flow control, and many others.
标签： Engineering Protocol
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