Many wireless communications channels consist of multiple signal paths from the transmitter to receiver. This multiplicity of paths leads to a phenomenon known as multipath fading. The multiple paths are caused by the presence of objects in the physical environment that, through the mechanisms of propagation, alter the path of radiated energy. These objects are referred to as scatterers. In the past, researchers often looked at ways to mitigate multipath scattering, such as in diversity systems. Multiple-input, multiple-output (MIMO) systems, on the other hand, use multipath diversity to their advantage; a MIMO system has the ability to translate increased spatial diversity into increased channel capacity.
標(biāo)簽： Multiple-Output Multiple-Input Channel Models
上傳時(shí)間： 2020-05-31
上傳用戶：shancjb
the second ediyion of this text is a much larger work than the first edition,having needed to expand with extensively new section on data
標(biāo)簽： Networks and Telecommunications
上傳時(shí)間： 2020-05-31
上傳用戶：shancjb
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.
標(biāo)簽： Electromagnetics Techniques Numerical in
上傳時(shí)間： 2020-05-31
上傳用戶：shancjb
Orthogonal frequency division multiplexing (OFDM) has been shown to be an effective technique to combat multipath fading in wireless channels. It has been and is going to be used in various wireless communication systems. This book gives a comprehensive introduction on the theory and practice of OFDM for wireless communications.
標(biāo)簽： Multiplexing Orthogonal Frequency Division
上傳時(shí)間： 2020-05-31
上傳用戶：shancjb
This book is intended for the graduate or advanced undergraduate engineer. The primary motivation for developing the text was to present a complete tutorial of phase-locked loops with a consistent notation. I believe this is critical for the practicing engineer who uses the text as a self-study guide.
標(biāo)簽： Communications Phase-Locked Wireless Loops for
上傳時(shí)間： 2020-05-31
上傳用戶：shancjb
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.
標(biāo)簽： Communications Physical Security Wireless Layer in
上傳時(shí)間： 2020-05-31
上傳用戶：shancjb
Some tine ago it become apparent the the first edition of this book was rapidly approaching its sell-by date,since many aspects needed revise.There were two obvious courses of action : to forget the whole thing and concentrate my energies on other pursuits such as golf or fishing, or to embark on a new edition.For several reasons Iwas persuaded that a new edition was a worthwhile endeavour;many people had made complimentary remakrs or written complinentary letters about the first edition and I understood that it had become a recommended text for several postgraduate coures.
標(biāo)簽： TMobile Radio Propagation Channel
上傳時(shí)間： 2020-06-01
上傳用戶：shancjb
In this book we focus on the basic signal processing that underlies current and future ultra wideband systems. By looking at signal processing in this way we hope this text will be useful even as UWB applications mature and change or regulations regarding ultra wideband systems are modified. The current UWB field is extremely dynamic, with new techniques and ideas being presented at every communications and signal-processing conference. The basic signal-processing techniques presented in this text though will not change for some time to come. Thus, we have taken a somewhat theoretical approach, which we believe is longer lasting and more useful to the reader in the long term than an up-to-the-minute summary that is out of date as soon as it is published.
標(biāo)簽： Wideband Signals Systems Ultra 1st
上傳時(shí)間： 2020-06-01
上傳用戶：shancjb
Once upon a time, cellular wireless networks provided two basic services: voice telephony and low-rate text messaging. Users in the network were separated by orthogonal multiple access schemes, and cells by generous frequency reuse patterns [1]. Since then, the proliferation of wireless services, fierce competition, andthe emergenceof new service classes such as wireless data and multimediahave resulted in an ever increasing pressure on network operators to use resources in a moreefficient manner.In the contextof wireless networks,two of the most common resources are power and spectrum—and, due to regulations, these resources are typically scarce. Hence, in contrast to wired networks, overprovisioning is not feasible in wireless networks.
標(biāo)簽： Maximization Nonconvex Wireless Utility Systems in
上傳時(shí)間： 2020-06-01
上傳用戶：shancjb
Two of the major developments reshaping the telecommunications landscape are mobile wireless connectivity and the migration of voice telephone services to IP technology. Those two ideas come together in networks that carry voice services over a wireless LAN (VoWLAN). The purpose of this text is to provide network professionals with the technical background and practical guidance needed to deploy these networks successfully.
上傳時(shí)間： 2020-06-01
上傳用戶：shancjb
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