-
To meet the future demand for huge traffic volume of wireless data service, the research on the fifth generation
(5G) mobile communication systems has been undertaken in recent years. It is expected that the spectral and energy
efficiencies in 5G mobile communication systems should be ten-fold higher than the ones in the fourth generation
(4G) mobile communication systems. Therefore, it is important to further exploit the potential of spatial multiplexing
of multiple antennas. In the last twenty years, multiple-input multiple-output (MIMO) antenna techniques have been
considered as the key techniques to increase the capacity of wireless communication systems. When a large-scale
antenna array (which is also called massive MIMO) is equipped in a base-station, or a large number of distributed
antennas (which is also called large-scale distributed MIMO) are deployed, the spectral and energy efficiencies can
be further improved by using spatial domain multiple access. This paper provides an overview of massive MIMO
and large-scale distributed MIMO systems, including spectral efficiency analysis, channel state information (CSI)
acquisition, wireless transmission technology, and resource allocation.
標簽：
Large-scale
Antenna
Systems
上傳時間：
2020-05-27
上傳用戶：shancjb
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Mobilenetworkoperatorswillmeetmanychallengesinthecomingyears.Itisexpectedthatthe
numberofpeopleconnected,wirelineandwireless,willreachfivebillionby2015.Atthesame
time, people use more wireless services and they expect similar user experience to what they
can now get from fixed networks. Because of that we will see a hundred-fold increase in
network traffic in the near future. At the same time markets are saturating and the revenue per
bit is dropping.
標簽：
Self-Organising
Networks
LTE
上傳時間：
2020-05-27
上傳用戶：shancjb
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Smartphones have become a key element in providing greater user access to the
mobile Internet. Many complex applications which used to be limited to PCs, have
been developed and operated on smartphones. These applications extend the
functionalities of smartphones, making them more convenient for users to be
connected. However, they also greatly increase the power consumption of
smartphones, making users frustrated with long delays in Web browsing.
標簽：
Browsing
Mobile
Cloud
Using
Web
the
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
-
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
-
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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This book focuses on the study and development of one of the most
advanced topics in broadband wireless communications systems:
power efficiency and power consumption in wireless communications
systems, especially of mobile devices. Hence, the main focus of this
book is on the most recent techniques for the conservation of power
and increase in power efficiency.
標簽：
Communications
Efficiency
Broadband
Power
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
-
We are currently witnessing an increase in telecommunications norms and
standards given the recent advances in this domain. The increasing number of
normalized standards paves the way for an increase in the range of offers and
services available for each consumer. Moreover, the majority of available radio
frequencies have already been allocated.
標簽：
Allocation
Resource
Radio
上傳時間：
2020-06-01
上傳用戶：shancjb
-
Software defined radio (SDR) is an exciting new field for the wireless indus-
try; it is gaining momentum and beginning to be included in commercial
and defense products. The technology offers the potential to revolutionize
the way radios are designed, manufactured, deployed, and used. SDR prom-
ises to increase flexibility, extend hardware lifetime, lower costs, and reduce
time to market
標簽：
Software
Defined
Radio
for
3G
上傳時間：
2020-06-01
上傳用戶：shancjb
