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During the past two decades there has been a substantial growth in research in
wireless communications. The number of journals published from various parts of
the world catering to the research community has grown exponentially. Despite
such a growth, the engineering community still needs more information so as to
thoroughly comprehend wireless channel characteristics. What specifically must be
understood are the effects of channel degradation brought on by statistical fluctua-
tions in the channel.
標簽：
Shadowing
Wireless
Systems
Fading
and
in
上傳時間：
2020-05-27
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During the past decade, many wireless communication techniques have been
developedto achievevariousgoals suchas higherdata rate,morerobustlink quality,
and higher number of users in a given bandwidth. For wireless communication
systems, depending on the availability of a feedback link, two approaches can be
considered: namely open and closed loop. Open loop communication system that
does not exploit the channel knowledge at the transmitter is now well understood
from both a theoretical and practical point of view.
標簽：
Communication
Strategies
Feedback
Wireless
for
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2020-05-27
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The first Third Generation Partnership Project (3GPP) Wideband Code Division
Multiple Access (WCDMA) networks were launched During 2002. By the end of 2005
there were 100 open WCDMA networks and a total of over 150 operators having
frequency licenses for WCDMA operation. Currently, the WCDMA networks are
deployedinUniversalMobileTelecommunicationsSystem(UMTS)bandaround2GHz
in Europe and Asia including Japan and Korea. WCDMA in America is deployed in the
existing 850 and 1900 spectrum allocations while the new 3G band at 1700/2100 is
expected to be available in the near future. 3GPP has defined the WCDMA operation
also for several additional bands, which are expected to be taken into use During the
coming years.
標簽：
HSDPAHSUPA
Access
Speed
Radio
UMTS
High
for
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2020-05-27
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During the 400 days and nights before we finalized this book on January 1, 2012,
we saw the sunset decorated by the raindrop, and were accompanied by the flowers
blooming to withering. All those past memories are engraved on our hearts and will
last eternally, cementing the most profound friendship in the world.
標簽：
LTE-Advanced
Technology
Interface
Air
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2020-05-27
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LTE-Advanced becomes a truly global standard for 4G cellular communications.
Relay, as one of the key technologies of LTE-Advanced, can significantly extend
the coverage, and improve the system throughput. LTE-A standards and tech-
nologies were described in several recent books where the limited pages for relay
feature prevent the detailed explanations of the technology. In this book, we tried
to provide an in-depth description of LTE-A relay development. More specifically,
significant portions are spent on relay channel modeling and potential technologies
During the study item phase of the development, although some of those tech-
nologies, such as Type 2 cooperative relay, multi-hop relay, relay with backhaul of
carrier aggregation, were not standardized in Release 10 LTE.
標簽：
LTE-Advanced
Technology
Relay
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2020-05-27
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This paper presents a Hidden Markov Model (HMM)-based speech
enhancement method, aiming at reducing non-stationary noise from speech
signals. The system is based on the assumption that the speech and the noise
are additive and uncorrelated. Cepstral features are used to extract statistical
information from both the speech and the noise. A-priori statistical
information is collected from long training sequences into ergodic hidden
Markov models. Given the ergodic models for the speech and the noise, a
compensated speech-noise model is created by means of parallel model
combination, using a log-normal approximation. During the compensation, the
mean of every mixture in the speech and noise model is stored. The stored
means are then used in the enhancement process to create the most likely
speech and noise power spectral distributions using the forward algorithm
combined with mixture probability. The distributions are used to generate a
Wiener filter for every observation. The paper includes a performance
evaluation of the speech enhancer for stationary as well as non-stationary
noise environment.
標簽：
Telecommunications
Processing
Signal
for
上傳時間：
2020-06-01
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Driven by the desire to boost the quality of service of wireless systems closer to that afforded
by wireline systems, space-time processing for multiple-input multiple-output (MIMO)
wireless communications research has drawn remarkable interest in recent years. Excit-
ing theoretical advances, complemented by rapid transition of research results to industry
products and services, have created a vibrant and growing area that is already established
by all counts. This offers a good opportunity to reflect on key developments in the area
During the past decade and also outline emerging trends.
標簽：
Space-Time
Processing
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2020-06-01
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The idea for this book was born During one of my project-related trips to the beautiful city
of Hangzhou in China, where in the role of Chief Architect I had to guide a team of very
young, very smart and extremely dedicated software developers and verification engineers.
Soon it became clear that as eager as the team was to jump into the coding, it did not have
any experience in system architecture and design and if I did not want to spend all my time in
constant travel between San Francisco and Hangzhou, the only option was to groom a number
of local junior architects. Logically, one of the first questions being asked by these carefully
selected future architects was whether I could recommend a book or other learning material
that could speed up the learning cycle. I could not. Of course, there were many books on
various related topics, but many of them were too old and most of the updated information
was either somewhere on the Internet dispersed between many sites and online magazines, or
buried in my brain along with many years of experience of system architecture.
標簽：
Telecommunication
Gateways
System
Design
for
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2020-06-01
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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
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2020-06-01
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During the past three decades, the world has seen signifi cant changes in the telecom-
munications industry. There has been rapid growth in wireless communications, as
seen by large expansion in mobile systems. Wireless communications have moved
from fi rst-generation (1G) systems primarily focused on voice communications to
third-generation (3G) systems dealing with Internet connectivity and multi-media
applications. The fourth-generation (4G) systems will be designed to connect wire-
less personal area networks (WPANs), wireless local area networks (WLANs) and
wireless wide-area networks (WWANs).
標簽：
Communications
Networking
Wireless
上傳時間：
2020-06-01
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