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Free Space Optical Communication (FSOC) is an effective alternative technology to
meet the Next Generation Network (NGN) demands as well as highly secured (mili-
tary) communications. FSOC includes various advantages like last mile access, easy
installation, free of Electro Magnetic interference (EMI)/Electro Magnetic Compatibil-
ity (EMC) and license free access etc. In FSOC, the optical beam propagation in the
turbulentatmosphereisseverelyaffectedbyvariousfactorssuspendedinthechannel,
geographicallocationoftheinstallationsite,terraintypeandmeteorologicalchanges.
Therefore a rigorous experimental study over a longer period becomes significant to
analyze the quality and reliability of the FSOC channel and the maximum data rate
that the system can operate since data transmission is completely season dependent.
標簽:
Communication
Optical
System
Space
Free
上傳時間:
2020-05-27
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-
The recent developments in full duplex (FD) commu-
nication promise doubling the capacity of cellular networks using
self interference cancellation (SIC) techniques. FD small cells
with device-to-device (D2D) communication links could achieve
the expected capacity of the future cellular networks (5G). In
this work, we consider joint scheduling and dynamic power
algorithm (DPA) for a single cell FD small cell network with
D2D links (D2DLs). We formulate the optimal user selection and
power control as a non-linear programming (NLP) optimization
problem to get the optimal user scheduling and transmission
power in a given TTI. Our numerical results show that using
DPA gives better overall throughput performance than full power
transmission algorithm (FPA). Also, simultaneous transmissions
(combination of uplink (UL), downlink (DL), and D2D occur
80% of the time thereby increasing the spectral efficiency and
network capacity
標簽:
Full-Duplex
Cells
Small
上傳時間:
2020-05-27
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-
We were on the lookout for ice.
I was in a 32 foot sailing yacht with writer and explorer Tristan Gooley, undertaking a
double-handed sail from Scotland through the Faroes up to 66 33 45.7 N and the midnight
sun. Now sailing out of the Arctic Circle we were approaching Iceland from the north, heading
for the Denmark Straits, where ice flowed south. The Admiralty Pilot warned of bergs but the
ice charts we had sailed with were over a week old. We needed an update.
標簽:
interference
Analysis
上傳時間:
2020-05-27
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-
This research work aims at eliminating the off-chip RF SAW filters from fre-
quency division duplexed (FDD) receivers. In the first approach, a monolithic passive
RF filter was constructed using on-chip capacitors and bondwire inductors. The bond-
wire characteristics were studied in details and the effect of mutual inductive coupling
between the bondwires on the filter performance was analyzed. Based on that, a bond-
wire configuration was proposed to improve the frequency response of the filter. The
filter was implemented in 0.18 μm CMOS process for WCDMA applications.
標簽:
interference
Mitigation
Techniques
上傳時間:
2020-05-27
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-
At the macroscopic level of system layout, the most important issue is path loss. In the
older mobile radio systems that are limited by receiver noise, path loss determines SNR and
the maximum coverage area. In cellular systems, where the limiting factor is cochannel
interference, path loss determines the degree to which transmitters in different cells interfere
with each other, and therefore the minimum separation before channels can be reused.
標簽:
Characteristics
Channel
Mobile
上傳時間:
2020-05-30
上傳用戶:shancjb
-
This book is about multipoint cooperative communication, a key technology to
overcome the long-standing problem of limited transmission rate caused by inter-
point interference. However, the multipoint cooperative communication is not an
isolated technology. Instead, it covers a vast range of research areas such as the
multiple-input multiple-outputsystem, the relay network, channel state information
issues, inter-point radio resource management operations, coordinated or joint
transmissions, etc. We suppose that any attempt trying to thoroughly analyze the
multipoint cooperative communication technology might end up working on a
cyclopedia for modern communication systems and easily get lost in discussing all
kinds of cooperative communication schemes as well as the associated models and
their variations.
標簽:
Communication
Multi-point
Cooperative
Systems
上傳時間:
2020-05-31
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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
-
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
-
Transmit power in wireless cellular networks is a key degree of freedom
in the management of interference, energy, and connectivity. Power
control in both uplink and downlink of a cellular network has been
extensively studied, especially over the last 15 years, and some of the
results have enabled the continuous evolution and significant impact of
the digital cellular technology.
標簽:
Cellular
Networks
Wireless
Control
Power
in
上傳時間:
2020-05-31
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-
Wireless means different things to different people. For this book, it refers
to the radio systems that provide point-to-point, point-to-multipoint, and
Earth-space communications over transmission links that propagate outside
buildings through the lower atmosphere. Wireless systems are being built
that provide data transmission between computers and other devices on
one’s own desk. These are part of the wireless world but not the part where,
except for interference perhaps, the atmosphere has any influence. The intent
of this book is to provide a description of the physical phenomena that can
affect propagation through the atmosphere, present sample measurements
and statistics, and provide models that system designers can use to calculate
their link budgets and estimate the limitations the atmosphere may place on
their design.
標簽:
Communication
Propagation
Handbook
Wireless
for
上傳時間:
2020-05-31
上傳用戶:shancjb