-
Multiuser multiple-input-multiple-output (MU-
MIMO) systems are known to be hindered by dimensionality
loss due to channel state information (CSI) acquisition overhead.
In this paper, we investigate user-scheduling in MU-MIMO
systems on account of CSI acquisition overhead, where a base
station dynamically acquires user channels to avoid choking the
system with CSI overhead.
標簽：
Acquisition
Dynamic
Channel
上傳時間：
2020-05-27
上傳用戶：shancjb
-
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
-
The single-carrier frequency division multiple access (SC-FDMA)
system is a well-known system that has recently become a preferred
choice for mobile uplink channels. This is attributed to its advantages
such as the low peak-to-average power ratio (PAPR) and the use of
frequency domain equalizers. Low PAPR allows the system to relax
the specifications of linearity in the power amplifier of the mobile
terminal, which reduces cost and power consumption.
標簽：
Communications
SC-FDMA
Mobile
for
上傳時間：
2020-06-01
上傳用戶：shancjb
-
In Helsinki during a visiting lecture, an internationally well-known professor in communica-
tionssaid,‘Inthecommunicationssocietywehavemanagedtoconvertourproposalsandideas
to real products, not like in the control engineering society. They have very nice papers and
strong mathematics but most of the real systems still use the old PID controllers!’. As our
background is mainly in control as well as communications engineering, we know that this
thought is not very accurate. We agree that most of the practical controllers are analog and
digital PID controllers, simply because they are very reliable and able to achieve the required
control goals successfully. Most of the controllers can be explained in terms of PID. The
reasons behind this impressive performance of PID will be explained in Chapter 2.
標簽：
Communications
Engineering
Wireless
Systems
in
上傳時間：
2020-06-01
上傳用戶：shancjb
-
The dictionary definition of telecommunications is ‘communication over long
distance by cable, telegraph, telephone or broadcasting’, but since its initiation over
100yearsagothingshavemovedrapidly.Telecommunicationsisnowaverycomplex
industrywithmanydifferentpressures,operatinginahighlydynamic environment.It
is best viewed as part of a wider industry known as information and communication
technology (ICT). The purpose of this chapter is to explain where telecommunication
fits in, to highlight some of the complexities – hopefully to simplify them – and to
position the industry in today’s dynamic business environment.
標簽：
Telecommunications
Understanding
Business
上傳時間：
2020-06-01
上傳用戶：shancjb
-
The explosion in demand for wireless services experienced over the past 20 years
has put significant pressure on system designers to increase the capacity of the
systems being deployed. While the spectral resource is very scarce and practically
exhausted, the biggest possibilities are predicted to be in the areas of spectral reuse
by unlicensed users or in exploiting the spatial dimension of the wireless channels.
The former approach is now under intense development and is known as the cogni-
tive radio approach (Haykin 2005).
標簽：
Multi-Antenna
Wireless
Channels
Modeling
上傳時間：
2020-06-01
上傳用戶：shancjb
-
Static electricity is the most ancient form of electricity known to humans. More
than 2000 years ago, the Greeks recognized the attraction between certain mate-
rials when they were rubbed together; indeed, the word electricity comes from
the Greek elektron, which means amber. During the seventeenth and eighteenth
centuries, several key experiments were conducted to understand and measure
static electricity. But the discovery of electromagnetism and its formidable break-
through has rapidly outgrown interest in static electricity. Even today, where
the industrial applications of static electricity are not insignificant, they cannot
compare with those of electromagnetism and electrodynamics.
標簽：
Understand
Discharge
Electro
Static
上傳時間：
2020-06-05
上傳用戶：shancjb
-
Electrostatic discharge (ESD) phenomena have been known to mankind since the Greek
Empire when Thales of Miletus, one of the Seven Sages of Greece, noticed the attraction of
strands of hay to amber, leading to the coining of the word ‘‘electron.’’ In the 17th century,
Gilbert and Cabeo addressed the attractive and repulsive nature of electricity. In the 18th
century, a rapid increase of interest occurred for scientists in the understanding of electrical
physics—Gray, du Fay, Nollet, Musschenbroeck, Franklin, Watson, Aepinus, Canton,
標簽：
Circuits
Devices
ESD
and
上傳時間：
2020-06-05
上傳用戶：shancjb
-
Electrostatic discharge (ESD) phenomena have been known to mankind since Thales of
Miletus in approximately 600 B.C.E. noticed the attraction of strands of hay to amber.
Two thousand six hundred years have passed and the quest to obtain a better under-
standing of electrostatics and ESD phenomenon continues. Today, the manufacturing
of microelectronics has continued the interest in the field of electrostatic phenomenon
spanning factory issues, tooling, materials, and the microelectronic industry
標簽：
Devices
Physics
ESD
and
上傳時間：
2020-06-05
上傳用戶：shancjb
-
The phenomenon of electrostatic discharge (ESD) has been known for a long time, but
recently a growing interest has been observed in ESD in radio frequency (RF) technology
and ESD issues in RF applications.
標簽：
Technology
Circuits
ESD
and
RF
上傳時間：
2020-06-05
上傳用戶：shancjb
