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Wireless is one of the most rapidly developing technologies in our time, with dazzling
new products and services emerging on an almost daily basis. These developments present
enormous challenges for communications engineers, as the demand for increased wireless
CAPACITY grows explosively. Indeed, the discipline of wireless communications presents
many challenges to designers that arise as a result of the demanding nature of the physical
medium and the complexities in the dynamics of the underlying network.
標簽：
Communications
Wireless
MIMO
上傳時間：
2020-05-28
上傳用戶：shancjb
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Wireless metropolitan area networks (WirelessMANs) is emerging as a promising
broadband wireless access (BWA) technology to provide high-speed, high bandwidth
efficiency and high-CAPACITY multimedia services for residential as well as enterprise
applications. It is observed that WirelessMAN (e.g., WiMAX) is even regarded as a 4G
technology. For the success of the WirelessMANs, international standardization organiza-
tions are very actively specifying the standards IEEE 802.16, ETSI HiperMAN and Korea
WiBro.
標簽：
BroadbanMobile WiMAX Toward Broadband Wirelessd
Wireless
Mobile
Toward
WiMAX
上傳時間：
2020-05-30
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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The family of recent wireless standards included the optional employment of Multiple-Input
Multiple-Output(MIMO)techniques.This was motivatedby the observationaccordingto the
classic Shannon–Hartley law that the achievable channel CAPACITY increases logarithmically
with the transmit power. In contrast, the MIMO CAPACITY increases linearly with the number
of transmit antennas, provided that the number of receive antennas is equal to the number
of transmit antennas. With the further proviso that the total transmit power is increased in
proportion to the number of transmit antennas, a linear CAPACITY increase is achieved upon
increasing the transmit power, which justifies the spectacular success of MIMO systems.
標簽：
Multi-Functional
Systems
MIMO
上傳時間：
2020-05-31
上傳用戶：shancjb
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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.
標簽：
Multiple-Output
Multiple-Input
Channel
Models
上傳時間：
2020-05-31
上傳用戶：shancjb
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The family of recent wireless standards included the optional employment of MIMO tyechniques.
This was motivated by the observation according to the classic Shannon-Hartley law the achiev-
able channel CAPACITY increases logarithmically with the transmit power. By contrast, the MIMO
CAPACITY increases linearly with the number of transmit antennas, provided that the number of
receive antennas is equal to the number of transmit antennas.
標簽：
Simulation
Modeling
Network
and
上傳時間：
2020-05-31
上傳用戶：shancjb
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Optical wireless communication is an emerging and dynamic research and development
area that has generated a vast number of interesting solutions to very complicated
communication challenges. For example, high data rate, high CAPACITY and minimum
interference links for short-range communication for inter-building communication,
computer-to-computer communication, or sensor networks. At the opposite extreme is
a long-range link in the order of millions of kilometers in the new mission to Mars
and other solar system planets.
標簽：
Communication
Wireless
Optical
Systems
上傳時間：
2020-05-31
上傳用戶：shancjb
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Ever since ancient times, people continuously have devised new techniques and
technologies for communicating their ideas, needs, and desires to others. Thus,
many forms of increasingly complex communication systems have appeared
over the years. The basic motivations behind each new one were to improve the
transmission fidelity so that fewer errors occur in the received message, to
increase the transmission CAPACITY of a communication link so that more infor-
mation could be sent, or to increase the transmission distance between relay sta-
tions so that messages can be sent farther without the need to restore the signal
fidelity periodically along its path.
標簽：
Communications
Essentials
Optical
上傳時間：
2020-05-31
上傳用戶：shancjb
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Wireless networking is undergoing a transformation from what has
been primarily a medium for supporting voice traffic between telephones,
into what is increasingly becoming a medium for supporting traffic among
a variety of digital devices transmitting media of many types (voice,
data, images, video. etc.) Wireline networking underwent a similar
transformation in the 1990s, which led to an enormous build-up in the
CAPACITY of such networks, primarily through the addition of new optical
fiber, switches and other infrastructure.
標簽：
Multiusers
Detection
Wireless
Networks
上傳時間：
2020-06-01
上傳用戶：shancjb
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Wireless communications, together with its applications and underlying technologies, is
among today’s most active areas of technology development. The very rapid pace of im-
provements in both custom and programmable integrated circuits for signal processing ap-
plications has led to the justfiable view of advanced signal processing as a key enabler of the
aggressively escalating CAPACITY demands of emerging wireless systems. Consequently, there
has been a tremendous and very widespread effort on the part of the research community
to develop novel signal processing techniques that can fulfill this promise.
標簽：
Communication
Wireless
Systems
上傳時間：
2020-06-01
上傳用戶：shancjb
