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Before delving into the details of orthogonal frequency division multiplexing (OFDM), relevant
background material must be presented first. The purpose of this chapter is to provide the necessary
building blocks for the development of OFDM principles. Included in this chapter are reviews of stochastic
and random process, discrete-time signals and systems, and the Discrete Fourier Transform (DFT). Tooled
with the necessary mathematical foundation, we proceed with an overview of digital communication
systems and OFDM communication systems. We conclude the chapter with summaries of the OFDM
wireless LAN standards currently in existence and a high-level comparison of single carrier systems versus
OFDM.
標簽:
Wireless
OFDM
LANS
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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.
標簽:
Communication
Principles
Simulation
Systems
of
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Many good textbooks exist on probability and random processes written at the under-
graduate level to the research level. However, there is no one handy and ready book
that explains most of the essential topics, such as random variables and most of their
frequently used discrete and continuous probability distribution functions; moments,
transformation, and convergences of random variables; characteristic and generating
functions; estimation theory and the associated orthogonality principle; vector random
variables; random processes and their autocovariance and cross-covariance functions; sta-
tionarity concepts; and random processes through linear systems and the associated
Wiener and Kalman filters.
標簽:
Probability
Processes
Random
and
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Convergence between the two largest networks (Telecom and IP) is taking place
very rapidly and at diff erent levels: (1) network level: unifi cation of IP networks
with traditional Telecom networks through evolving standards (Session Initiation
Protocol (SIP), Realtime Transfer Protocol (RTP), SS7, 3G) to support interopera-
bility; (2) service level: traditional Telecom services like voice calls are being provi-
sioned on the IP backbone (VoIP), while traditional IP services (most data-driven
services such as multimedia, browsing, chatting, gaming, etc.) are accessible over
the Telecom network.
標簽:
Platforms
Delivery
Service
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Part I provides a compact survey on classical stochastic geometry models. The basic models defined
in this part will be used and extended throughout the whole monograph, and in particular to SINR based
models. Note however that these classical stochastic models can be used in a variety of contexts which
go far beyond the modeling of wireless networks. Chapter 1 reviews the definition and basic properties of
Poisson point processes in Euclidean space. We review key operations on Poisson point processes (thinning,
superposition, displacement) as well as key formulas like Campbell’s formula. Chapter 2 is focused on
properties of the spatial shot-noise process: its continuity properties, its Laplace transform, its moments
etc. Both additive and max shot-noise processes are studied. Chapter 3 bears on coverage processes,
and in particular on the Boolean model. Its basic coverage characteristics are reviewed. We also give a
brief account of its percolation properties. Chapter 4 studies random tessellations; the main focus is on
Poisson–Voronoi tessellations and cells. We also discuss various random objects associated with bivariate
point processes such as the set of points of the first point process that fall in a Voronoi cell w.r.t. the second
point process.
標簽:
Stochastic
Geometry
Networks
Wireless
Volume
and
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The first edition of this book was published in 1992. Nine years later it had become
clear that a second edition was required because of the rapidly changing nature of
telecommunication. In 1992, the Internet was in existence but it was not the
household word that it is in the year 2001. Cellular telephones were also in use
but they had not yet achieved the popularity that they enjoy today. In the current
edition, Chapter 1 has been revised to include a section on the Internet. Chapter 10 is
new and it covers the facsimile machine; I had overlooked this important tele-
communication device in the first edition. Chapter 11 is also new and it describes the
pager, the cordless telephone and the cellular telephone system. These are examples
of a growing trend in telecommunications to go ‘‘wireless’’.
標簽:
Telecommunication
Circuit
Design
2nd
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The first practical examples of mobile communications were used in many countries like
the USA, the UK and Germany in military services, and played a significant role in the
First World War to transfer important information from the front to headquarters to take
further actions. Good and secure wireless communications were an important need for all
military services – army, navy and air force. In this respect, the Second World War was a big
experimental battlefield for the development and evolution of mobile radio. It was in the
interests of governments that after the Second World War the military investment should
be paid back by civilian use, and all western European countries started their so-called first
generation of mobile communication networks.
標簽:
Multimedia
Business
Mobile
The
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In the two years since this book was first published, ultra wideband (UWB) has
advanced and consolidated as a technology, and many more people are aware of the
possibilities for this exciting technology. We too have expanded and consolidated
materials in this second edition in the hope that ‘Ultra Wideband: Signals and Systems
in Communication Engineering’ will continue to prove a useful tool for many students
and engineers to come to an understanding of the basic technologies for UWB.
標簽:
Wideband
Signals
Systems
Ultra
and
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In this first part of the book the Vienna Link Level (LL) Simulators are described.
The first chapter provides basics of LL simulations, introduces the most common
variables and parameters as well as the transceiver structures that are applied in
Long-Term Evolution (LTE) and Long-Term Evolution-Advanced (LTEA). We
focus here mostly on the Downlink (DL) of LTE as most results reported in later
chapters are related to DL transmissions.
標簽:
LTE-Advanced
Simulators
Vienna
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Second-generation telecommunication systems, such as the Global System for Mobile
Communications (GSM), enabled voice traffic to go wireless: the number of mobile phones
exceeds the number of landline phones and the mobile phone penetration is approaching
100% in several markets. The data-handling capabilities of second-generation systems are
limited, however, and third-generation systems are needed to provide the high bit-rate
services that enable high-quality images and video to be transmitted and received, and to
provide access to the Web with higher data rates.
標簽:
Evolution
WCDMA
UMTS
HSPA
LTE
for
and
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