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With the rapid growth in the number of wireless applications, services and devices,
using a single wireless technology such as a second generation (2G) and third gener-
ation (3G) wireless system would not be Efficient to deliver high speed data rate and
quality-of-service (QoS) support to mobile users in a seamless way. The next genera-
tion wireless systems (also sometimes referred to as Fourth generation (4G) systems)
are being devised with the vision of heterogeneity in which a mobile user/device will
be able to connect to multiple wireless networks (e.g., WLAN, cellular, WMAN)
simultaneously.
標簽：
Heterogeneous
Wireless
Networks
Access
上傳時間：
2020-05-27
上傳用戶：shancjb
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Radio frequency (RF) power amplifiers are used in everyday life for many applica-
tions including cellular phones, magnetic resonance imaging, semiconductor wafer
processing for chip manufacturing, etc. Therefore, the design and performance of
RF amplifiers carry great importance for the proper functionality of these devices.
Furthermore, several industrial and military applications require low-profile yet
high-powered and Efficient power amplifiers.
標簽：
Introduction
Amplifier
Design
Power
to
RF
上傳時間：
2020-05-27
上傳用戶：shancjb
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An optical fiber amplifier is a key component for enabling Efficient transmission of
wavelength-divisionmultiplexed(WDM)signalsoverlongdistances.Eventhough
many alternative technologies were available, erbium-doped fiber amplifiers won
theraceduringtheearly1990sandbecameastandardcomponentforlong-haulopti-
caltelecommunicationssystems.However,owingtotherecentsuccessinproducing
low-cost, high-power, semiconductor lasers operating near 1450 nm, the Raman
amplifiertechnologyhasalsogainedprominenceinthedeploymentofmodernlight-
wavesystems.Moreover,becauseofthepushforintegratedoptoelectroniccircuits,
semiconductor optical amplifiers, rare-earth-doped planar waveguide amplifiers,
and silicon optical amplifiers are also gaining much interest these days.
標簽：
Propagation
Light
Media
Gain
in
上傳時間：
2020-05-27
上傳用戶：shancjb
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With the rapid growth of the wireless mobile applications, wireless voice has
begun to challenge wireline voice, whereas the desire to access e-mail, surf the
Web or download music (e.g., MP3) wirelessly is increasing for wireless data.
While second generation (2G) cellular wireless systems, such as cdmaOne1,
GSM2 and TDMA3, introduced digital technology to wireless cellular systems
to deal with the increasing demand for wireless applications, there is still the
need for more spectrally Efficient technologies for two reasons. First, wireless
voice capacity is expected to continue to grow. Second, the introduction of
high-speed wireless data will require more bandwidth.
標簽：
Wireless
Systems
Mobile
Beyond
and
3G
上傳時間：
2020-05-30
上傳用戶：shancjb
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In the past few decades, a technological revolution has occurred that has changed
the way we live in dramatic ways. This technological revolution is the result of
the emergence and evolution of a wide variety of new wireless networking tech-
nologies. Now people using these technologies are able to access the network and
control many applications at will with their handheld devices anywhere, anytime.
Although these technologies have made a long lasting impact in the revolution, it
has also opened up various challenging issues which are yet to be resolved to make
them more Efficient and cost-effective.
標簽：
Next-Generation
Technologies
Wireless
上傳時間：
2020-05-31
上傳用戶：shancjb
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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.
標簽：
Communications
Physical
Security
Wireless
Layer
in
上傳時間：
2020-05-31
上傳用戶：shancjb
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Mobile operators must continuously pursue cost‐
effective and Efficient solutions to meet the high data
demand requirements of their subscribers. Limited spectrum
allocations and non‐contiguous spectrum blocks continue
to pose challenges for mobile operators supporting large
data uploads and downloads across their networks. With the
increase in video and social media content, the challenges
have increased exponentially.
標簽：
qorvo-carrier-aggregation-fundame
ntals
上傳時間：
2020-05-31
上傳用戶：shancjb
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The multiple-input multiple-output (MIMO) technique provides higher bit rates
and better reliability in wireless systems. The Efficient design of RF transceivers
has a vital impact on the implementation of this technique. This first book is com-
pletely devoted to RF transceiver design for MIMO communications. The book
covers the most recent research in practical design and applications and can be
an important resource for graduate students, wireless designers, and practical
engineers.
標簽：
Transceiver
Design
RF
上傳時間：
2020-06-01
上傳用戶：shancjb
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The radio spectrum is one of the most precious resources which must be managed
to ensure Efficient access for the wireless communication services which use it. The
allocation and management of spectrum are administered by the regulatory
authorities. Traditionally, spectrum allocation is carried out exclusively of its use in
large geographic areas and assigning frequency bands to specific users or service
providers is proved to be inEfficient. Recently, substantial knowledge about
dynamic spectrum access scheme has been accumulated to enable Efficient spectrum
sharing.
標簽：
Management
Spectrum
Access
and
上傳時間：
2020-06-01
上傳用戶：shancjb
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Heterogeneous Network (HetNet): A network that consists of a mix of macro cells and low-power
nodes, e.g. Pico, Femto, Relay Node (RN) and Remote Radio Head (RRH)
標簽：
Efficient
Spectrum
Energy
and
上傳時間：
2020-06-01
上傳用戶：shancjb
