-
Multiple-Input Multiple-Output (MIMO) systems have recently been the
subject of intensive consideration in modem wireless communications as they
offer the potential of providing high capacity, thus unleashing a wide range of
applications in the wireless domain. The main feature of MIMO systems is the
use of space-time processing and Space-Time Codes (STCs). Among a variety
of STCs, orthogonal Space-Time Block Codes (STBCs) have a much simpler
decoding method, compared to other STCs
標簽：
Orthogonal
Space-Time
Processing
Complex
上傳時間：
2020-05-26
上傳用戶：shancjb
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Fundamentals of WiMAX was consciously written to appeal to a broad audience, and to be of
value to anyone who is interested in the IEEE 802.16e standards or wireless broadband networks
more generally. The book contains cutting-edge tutorials on the technical and theoretical under-
pinnings to WiMAX that are not available anywhere else, while also providing high-level over-
views that will be informative to the casual reader.
標簽：
Understanding
Fundamentals
WiMAX
of
上傳時間：
2020-05-27
上傳用戶：shancjb
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providing QoS while optimizing the LTE network in a cost efficient manner is
very challenging. Thus, radio scheduling is one of the most important functions
in mobile broadband networks. The design of a mobile network radio scheduler
holds several objectives that need to be satisfied, for example: the scheduler needs
to maximize the radio performance by efficiently distributing the limited radio re-
sources, since the operator’s revenue depends on it.
標簽：
Communications
Future
Mobile
LTE
上傳時間：
2020-05-27
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In this paper we revisit hybrid analog-digital precoding systems with emphasis on their modelling
and radio-frequency (RF) losses, to realistically evaluate their benefits in 5G system implementations.
For this, we decompose the analog beamforming networks (ABFN) as a bank of commonly used RF
components and formulate realistic model constraints based on their S-parameters. Specifically, we
concentrate on fully-connected ABFN (FC-ABFN) and Butler networks for implementing the discrete
Fourier transform (DFT) in the RF domain. The results presented in this paper reveal that the performance
and energy efficiency of hybrid precoding systems are severely affected, once practical factors are
considered in the overall design. In this context, we also show that Butler RF networks are capable of
providing better performances than FC-ABFN for systems with a large number of RF chains.
標簽：
Analog-Digital
Precoding
Hybrid
上傳時間：
2020-05-27
上傳用戶：shancjb
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The third generation (3G) mobile communication system is the next big thing
in the world of mobile telecommunications. The first generation included
analog mobile phones [e.g., Total Access Communications Systems
(TACS), Nordic Mobile Telephone (NMT), and Advanced Mobile Phone
Service (AMPS)], and the second generation (2G) included digital mobile
phones [e.g., global system for mobile communications (GSM), personal
digital cellular (PDC), and digital AMPS (D-AMPS)]. The 3G will bring
digital multimedia handsets with high data transmission rates, capable of
providing much more than basic voice calls.
標簽：
Communications
Introduction
Mobile
3G
to
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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Recent decades have shown a tremendous expansion of the Internet. The number of
connected terminals has increased by orders of magnitude, traffic has grown exponen-
tially, coverage has become ubiquitous and worldwide, and today’s sophisticated Web
2.0 applications are increasingly providing services which hitherto have been the realm
of telecommunications, such as Skype and video conferencing. This has even led to the
thought that access to the Internet might one day be a universal right of every citizen.
This evolution will accelerate in the coming decades.
標簽：
Networking
Personal
Networks
Wireless
上傳時間：
2020-05-31
上傳用戶：shancjb
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Communication has been one of the deepest needs of the human race throughout recorded
history. It is essential to forming social unions, to educating the young, and to expressing a
myriad of emotions and needs. Good communication is central to a civilized society.
The various communication disciplines in engineering have the purpose of providing technological
aids to human communication. One could view the smoke signals and drum rolls of primitive
societies as being technological aids to communication, but communication technology as we
view it today became important with telegraphy, then telephony, then video, then computer
communication, and today the amazing mixture of all of these in inexpensive, small portable
devices.
標簽：
communication
Principles
digital
of
上傳時間：
2020-05-31
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Intensive development of digital technologies coincided in time with the beginning
of the new era in telecommunications. It made possible to formalize many proce-
dures of data exchange and to atomize some operations which made providing of
serviceandmakeworkofmanytelecommunicationworkersmucheasier. Somenew
telecommunication technologies were born out of the necessity for use of specific
configurations of network elements and networks, as well as for a possibility of
providing maximum characteristics of efficiency combined with high requirements
to the stability of operation, the overcoming of different catastrophic situations and
deadlockconditions,such as failuresand ”pending”of the networkandthe like. The
thresholdbetweeninformationsystems andtelecommunicationsystems has become
practically invisible. It resulted in such a new term as ”infocommunication”
標簽：
Telecommunication+Systems
上傳時間：
2020-06-01
上傳用戶：shancjb
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This book is focused on designing and developing Representational State Transfer (REST)
platforms in Rails. REST is the architectural style of the Web, consisting of a set of
constraints that, applied to components, connectors, and data elements, constitute the
wider distributed hypermedia system that we know today: the World Wide Web.
There are a few good reasons why it makes more sense to build platforms instead of just
products or applications. Platforms are like ecosystems interconnecting different
applications, services, users, developers, and partners. Platforms foster innovation through
the inputs of their direct collaborators. By providing application programming interfaces
(APIs) and software development kits (SDKs), platforms are more customer driven.
標簽：
Development
Building
RESTful
Rails
上傳時間：
2020-06-06
上傳用戶：shancjb
