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Wireless communication is witnessing tremendous growth with great proliferation of different standards covering wide ,local and personal area networks
標簽：
Multi-Standard
Receivers
Wireless
CMOS
上傳時間：
2020-05-31
上傳用戶：shancjb
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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.
標簽：
Opportunistic
Spectrum
Sharing
上傳時間：
2020-05-31
上傳用戶：shancjb
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This book provides the essential design techniques for radio systems that
operate at frequencies of 3 MHz to 100 GHz and which will be employed in
the telecommunication service. We may also call these wireless systems,
wireless being synonymous with radio, Telecommunications is a vibrant indus-
try, particularly on the ‘‘radio side of the house.’’ The major supporter of this
upsurge in radio has been the IEEE and its 802 committees. We now devote
? . an entire chapter to wireless LANs WLANs detailed in IEEE 802.11. We
also now have subsections on IEEE 802.15, 802.16, 802.20 and the wireless
? . ? metropolitan area network WMAN . WiFi, WiMax,, and UWB ultra wide-
. band are described where these comparatively new radio specialties are
demonstrating spectacular growth.
標簽：
Telecommunication
Design
System
Radio
for
上傳時間：
2020-06-01
上傳用戶：shancjb
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Digital mobile wireless communication and the Internet have undergone a
fantastic growth in the last few years and, despite originating from two different
worlds, they are converging. This convergence corresponds to the evolution of
mobile systems towards the highest broadband data transmissions (GSM,
EDGE/GPRS, UMTS then HSDPA), while the computing world gets equipped with
wireless technologies such as Wi-Fi or Wi-Max.
標簽：
Reconfigurable
Systems
Mobile
Radio
上傳時間：
2020-06-01
上傳用戶：shancjb
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Radio frequency spectrum is a scarce and critical natural resource that is utilized for
many services including surveillance, navigation, communication, and broadcast-
ing. Recent years have seen tremendous growth in the use of spectrum especially by
commercial cellular operators. Ubiquitous use of smartphones and tablets is one
of the reasons behind an all-time high utilization of spectrum. As a result, cellular
operators are experiencing a shortage of radio spectrum to meet bandwidth
demands of users. On the other hand, spectrum measurements have shown that
much spectrum not held by cellular operators is underutilized even in dense urban
areas. This has motivated shared access to spectrum by secondary systems with no
or minimal impact on incumbent systems. Spectrum sharing is a promising
approach to solve the problem of spectrum congestion as it allows cellular operators
access to more spectrum in order to satisfy the ever-growing bandwidth demands of
commercial users.
標簽：
Spectrum
Sharing
Between
Radars
上傳時間：
2020-06-01
上傳用戶：shancjb
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The continuing explosive growth in mobile communication is demanding more spectrally
efficient radio access technologies than the prevalent second generation (2G) systems such as
GSM to handle just the voice traffic. We are already witnessing high levels of mobile
penetration exceeding 70% in some countries. It is anticipated that by 2010 more than half of
all communications will be carried out by mobile cellular networks. On the other hand, the
information revolution and changing life habits are bringing the requirement of commu-
nicating on a multimedia level to the mobile environment. But the data handling capabilities
and flexibility of the 2G cellular systems are limited.
標簽：
Planning
Network
UMTS
上傳時間：
2020-06-01
上傳用戶：shancjb
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The information age is exploding around us,
giving us access to dizzying amounts of data the instant it becomes available.
Smart phones and tablets provide an untethered experience that offers stream-
ing video, audio, and other media formats to just about any place on the planet.
Even people who are not “computer literate” use Facebook to catch up with
friends and family, use Google to research a new restaurant choice and print
directions to get there, or Tweet their reactions once they have sampled the
fare. The budding Internet-of-things will only catalyze this data eruption.
The infrastructure supporting these services is also growing exponentially,
and the technology that facilitates this rapid growth is virtualization.
標簽：
Virtualization
Essentials
上傳時間：
2020-06-01
上傳用戶：shancjb
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Visible light communications (VLC) is the name given to an optical wireless
communication system that carries information by modulating light in the visible spectrum
(400–700 nm) that is principally used for illumination [1–3]. The communications signal
is encoded on top of the illumination light. Interest in VLC has grown rapidly with the
growth of high power light emitting diodes (LEDs) in the visible spectrum. The
motivation to use the illumination light for communication is to save energy by exploiting
the illumination to carry information and, at the same time, to use technology that is
“green” in comparison to radio frequency (RF) technology, while using the existing
infrastructure of the lighting system.
標簽：
Communication
Visible
Light
上傳時間：
2020-06-01
上傳用戶：shancjb
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During the past three decades, the world has seen signifi cant changes in the telecom-
munications industry. There has been rapid growth in wireless communications, as
seen by large expansion in mobile systems. Wireless communications have moved
from fi rst-generation (1G) systems primarily focused on voice communications to
third-generation (3G) systems dealing with Internet connectivity and multi-media
applications. The fourth-generation (4G) systems will be designed to connect wire-
less personal area networks (WPANs), wireless local area networks (WLANs) and
wireless wide-area networks (WWANs).
標簽：
Communications
Networking
Wireless
上傳時間：
2020-06-01
上傳用戶：shancjb
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Contamination and electrostatic discharge (ESD) are now becoming recognized as factors
affecting yield and reliability in an ever-increasing number of industries. Whereas contam-
ination traditionally was recognized as affecting the semiconductor, disk drive, aerospace,
pharmaceutical, and medical device industries, today such industries as automobile and
food production are also discovering the benefits of contamination control. ESD control
has experienced a similar growth in applications.
標簽：
Contamination
Control
and
ESD
上傳時間：
2020-06-05
上傳用戶：shancjb
