Without conceding a blemish in the first edition, I think I had best COMe clean
and admit that I embarked on a second edition largely to adopt a more geometric
approach to the detection of signals in white Gaussian noise. Equally rigorous, yet
more intuitive, this approach is not only student-friendly, but also extends more
easily to the detection problem with random parameters and to the radar problem
Today’s wireless services have COMe a long way since the roll out of the
conventional voice-centric cellular systems. The demand for wireless access
in voice and high rate data multi-media applications has been increasing.
New generation wireless communication systems are aimed at accommodating
this demand through better resource management and improved transmission
technologies.
Mobile communication has gained significant importance in today’s society. As
of 2010, the number of mobile phone subscribers has surpassed 5 billion [ABI10],
and the global annual mobile revenue is soon expected to top $1 trillion [Inf10].
While these numbers appear promising for mobile operators at first sight, the
major game-changer that has COMe up recently is the fact that the market is
more and more driven by the demand for mobile data traffic [Cis10].
Nature is seldom kind. One of the most appealing uses for radio-
telephone systems—communication with people on the move—must over-
COMe radio transmission problems so difficult they challenge the imagina-
tion. A microwave radio signal transmitted between a fixed base station
and a moving vehicle in a typical urban environment exhibits extreme
variations in both amplitude and apparent frequency.
This book presents millimeter wave communication system design and analysis at the
level to produce an understanding of the interaction between a wireless system and its
front end so that the overall performance can be predicted. Gigabit wireless commu-
nications require a considerable amount of bandwidth, which can be supported by
millimeter waves. Millimeter wave technology has COMe of age, and at the time of
writing the standards of IEEE 802.15.3c, WiGig, Wireless HD TM , and the European
Computer Manufacturers Association have recently been finalized.
Mobile and wireless application development has COMe a long way in the past few
years. It has progressed beyond the hype of wireless Web applications for consumers
to the reality of high-value mobile applications for corporate users. Opportunities
abound for creating new mobile and wireless applications that provide vital benefits to
any business. A sampling of these benefits includes increased worker productivity,
reduced processing costs, heightened accuracy, and competitive advantage. In contrast
is the concern that developing mobile and wireless applications will involve many new
technologies and concepts that many corporate developers are still learning to use.
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.
Until the mid-1990s most readers would probably not have even COMe across the term soft-
ware defined radio (SDR), let alone had an idea what it referred to. Since then SDR has made
the transition from obscurity to mainstream, albeit still with many different understandings of
the terms – software radio, software defined radio, software based radio, reconfigurable radio.
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.
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.
