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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
-
Cognitive radios have become a vital solution that allows sharing of the scarce
frequency spectrum available for wireless systems. It has been demonstrated
that it can be used for future wireless systems as well as integrated into 4G/5G
wireless systems. Although there is a great amount of literature in the design of
cognitive radios from a system and networking point of view, there has been very
limited available literature detailing the circuit implementation of such systems.
Our textbook, Radio Frequency Integrated Circuit Design for Cognitive Radios, is
the first book to fill a disconnect in the literature between Cognitive Radio systems
and a detailed account of the circuit implementation and architectures required to
implement such systems. In addition, this book describes several novel concepts
that advance state-of-the-art cognitive radio systems.
標簽:
Cognitive
Systems
Design
Radio
RFIC
for
上傳時間:
2020-06-01
上傳用戶:shancjb
-
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
上傳用戶:shancjb
-
The radio spectrum is one of the most precious resources which must be managed
to ensure efficient access for the wireless communication services which use it. The
allocation and management of spectrum are administered by the regulatory
authorities. Traditionally, spectrum allocation is carried out exclusively of its use in
large geographic areas and assigning frequency bands to specific users or service
providers is proved to be inefficient. Recently, substantial knowledge about
dynamic spectrum access scheme has been accumulated to enable efficient spectrum
sharing.
標簽:
Management
Spectrum
Access
and
上傳時間:
2020-06-01
上傳用戶:shancjb
-
When 3GPP started standardizing the IMS a few years ago, most analysts expected the
number of IMS deploymentsto grow dramatically as soon the initial IMS specifications were
ready (3GPP Release 5 was functionallyfrozenin the first half of 2002and completedshortly
after that). While those predictions have proven to be too aggressive owing to a number of
upheavals hitting the ICT (Information and Communications Technologies) sector, we are
now seeing more and more commercial IMS-based service offerings in the market. At the
time of writing (May 2008), there are over 30 commercial IMS networks running live traffic,
addingup to over10million IMS users aroundthe world; the IMS is beingdeployedglobally.
In addition, there are plenty of ongoing market activities; it is estimated that over 130 IMS
contracts have been awarded to all IMS manufacturers. The number of IMS users will grow
substantially as these awarded contracts are launched commercially. At the same time, the
number of IMS users in presently deployed networks is steadily increasing as new services
are introduced and operators running these networks migrate their non-IMS users to their
IMS networks.
標簽:
Multimedia
Subsystem
The
IMS
3G
IP
上傳時間:
2020-06-01
上傳用戶:shancjb
-
The wide deployment of wireless networks and mobile technologies, along with the
significant increase in the number of mobile device users, have created a very strong
demand on various wireless-based, mobile-based software application systems and
enabling technologies. This not only provides many new business opportunities and
challenges to wireless and networking service providers, mobile technology ven-
dors, and software industry and solution integrators, butalso changes and enhances
people’s lives in many areas, including communications, information sharing and
exchange, commerce, home environment, education, and entertainment. Business
organizations and government agencies face new pressure fortechnology updatesto
upgrade their networking infrastructures with wireless connectivity to enhance
enterprise-oriented systems and solutions.
標簽:
Wireless-Based
Software
Systems
上傳時間:
2020-06-01
上傳用戶:shancjb
-
The Home Gateway Initiative (HGI) is a non-profit making organization which publishes guidelines,
requirements documents, white papers, vision papers, test plans and other documents concerning
broadband equipment and services which are deployed in the home.
標簽:
Evaluation
Discussion
Framework
Document
KPI
上傳時間:
2020-06-06
上傳用戶:shancjb
-
RFID (radio-frequency identification) is the use of a wireless non-contact system
that uses radio-frequencyelectromagnetic fields to transfer datafrom a tag attached
to an object, for the purposes of automatic identification and tracking [38]. The
basic technologies for RFID have been around for a long time. Its root can be traced
back to an espionage device designed in 1945 by Leon Theremin of the Soviet
Union,whichretransmittedincidentradiowaves modulatedwith audioinformation.
After decades of development, RFID systems have gain more and more attention
from both the research community and the industry.
標簽:
Infrastructure
RFID
as
an
上傳時間:
2020-06-08
上傳用戶:shancjb
-
This book is about the Arduino microcontroller and the Arduino concept. The visionary
ArduinoteamofMassimoBanzi,DavidCuartielles,TomIgoe,GianlucaMartino,andDavidMellis
launchedanewinnovationinmicrocontrollerhardwarein2005,theconceptofopensourcehardware.
There approach was to openly share details of microcontroller-based hardware design platforms to
stimulate the sharing of ideas and innovation.This concept has been popular in the software world
for many years.
標簽:
Microcontroller
Processing
Arduino
上傳時間:
2020-06-09
上傳用戶:shancjb
-
This book is about the Arduino microcontroller and the Arduino concept. The visionary
ArduinoteamofMassimoBanzi,DavidCuartielles,TomIgoe,GianlucaMartino,andDavidMellis
launchedanewinnovationinmicrocontrollerhardwarein2005,theconceptofopensourcehardware.
There approach was to openly share details of microcontroller-based hardware design platforms to
stimulate the sharing of ideas and innovation.This concept has been popular in the software world
for many years.
標簽:
Microcontroller
Processing
Everyone
Arduino
Part
for
上傳時間:
2020-06-09
上傳用戶:shancjb