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The writing of this book was prompted by two main developments in wireless
communications in the past decade. First is the huge surge of research activities in
physical-layer wireless communication theory. While this has been a subject of study
since the 60’s, recent developments in the field, such as opportunistic and multi-input
multi-output (MIMO) communication techniques, have brought completely new per-
spectives on how to Communicate over wireless channels.
標(biāo)簽：
Communication
Fundamentals
Wireless
of
上傳時(shí)間：
2020-05-27
上傳用戶：shancjb
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Wireless technologies like GSM, UMTS, LTE, Wireless LAN and Bluetooth have revolu-
tionized the way we Communicate and exchange data by making services like telephony and
Internet access available anytime and from almost anywhere. Today, a great variety of techni-
cal publications offer background information about these technologies but they all fall short
in one way or another. Books covering these technologies usually describe only one of the
systems in detail and are generally too complex as a first introduction. The Internet is also a
good source, but the articles one finds are usually too short and superficial or only deal with
a specific mechanism of one of the systems. For this reason, it was difficult for me to recom-
mend a single publication to students in my telecommunication classes, which I have been
teaching in addition to my work in the wireless telecommunication industry. This book aims
to change this.
標(biāo)簽：
GSM
LTE-Advanced
上傳時(shí)間：
2020-05-27
上傳用戶：shancjb
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There are few technologies that have had a more profound effect on people’s lives
than mobile communications. As recently as twenty years ago no one had a mobile
phone, while today 1.4 billion men, women and children depend on them. This now
exceeds the number of landline users, where it took the preceding one hundred years
to reach the 1 billion mark. The ability to make mobile voice calls turns out to be the
answer to a deeply felt need across different cultures who simply want to
Communicate.
標(biāo)簽：
Communications
Wireless
Mobile
and
上傳時(shí)間：
2020-05-30
上傳用戶：shancjb
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Advances in communication and networking technologies are rapidly making ubiq-
uitous network connectivity a reality. Wireless networks are indispensable for
supporting such access anywhere and at any time. Among various types of wire-
less networks, multihop wireless networks (MWNs) have been attracting increasing
attention for decades due to its broad civilian and military applications. Basically,
a MWN is a network of nodes connected by wireless communication links. Due
to the limited transmission range of the radio, many pairs of nodes in MWNs may
not be able to Communicate directly, hence they need other intermediate nodes to
forward packets for them. Routing in such networks is an important issue and it
poses great challenges.
標(biāo)簽：
Multihop
Wireless
Networks
上傳時(shí)間：
2020-05-31
上傳用戶：shancjb
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A mobile ad-hoc network (MANET) is formed by multiple moving nodes
equipped with wireless transceivers. The mobile nodes Communicate with
each other through multi-hop wireless links, where every node can transmit
and receive information. Mobile ad-hoc networks have become increasingly
important in areas where deployment of communications infrastructure is
difficult.
標(biāo)簽：
Telecommunications
Modeling
上傳時(shí)間：
2020-06-01
上傳用戶：shancjb
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Recent advances in wireless communication technologies have had a transforma-
tive impact on society and have directly contributed to several economic and social
aspects of daily life. Increasingly, the untethered exchange of information between
devices is becoming a prime requirement for further progress, which is placing an
ever greater demand on wireless bandwidth. The ultra wideband (UWB) system
marks a major milestone in this progress. Since 2002, when the FCC allowed the
unlicensed use of low-power, UWB radio signals in the 3.1–10.6GHz frequency
band, there has been significant synergistic advance in this technology at the cir-
cuits, architectural and communication systems levels. This technology allows for
devices to Communicate wirelessly, while coexisting with other users by ensuring
that its power density is sufficiently low so that it is perceived as noise to other
users.
標(biāo)簽：
Circuits
Wideband
Ultra
上傳時(shí)間：
2020-06-01
上傳用戶：shancjb
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The use of light to send messages is not new. Fires were used for signaling in
biblical times, smoke signals have been used for thousands of years and flashing
lights have been used to Communicate between warships at sea since the days of
Lord Nelson.
The idea of using glass fibre to carry an optical communications signal originated
with Alexander Graham Bell. However this idea had to wait some 80 years for
better glasses and low-cost electronics for it to become useful in practical
situations.
標(biāo)簽：
Communications
Understanding
Optical
上傳時(shí)間：
2020-06-01
上傳用戶：shancjb
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A wireless ad-hoc network is a wireless network deployed without any infrastructure. In
such a network, there is no access point or wireless router to forward messages among the
computing devices. Instead, these devices depend on the ad-hoc mode of their wireless net‐
work interface cards to Communicate with each other. If the nodes are within the transmis‐
sion range of the wireless signal, they can send messages to each other directly. Otherwise,
the nodes in between will forward the messages for them. Thus, each node is both an end
system and a router simultaneously.
標(biāo)簽：
WIRELESS
NETWORKS
AD-HOC
上傳時(shí)間：
2020-06-01
上傳用戶：shancjb
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Artificial Intelligence (AI) has undoubtedly been one of the most important buz-
zwords over the past years. The goal in AI is to design algorithms that transform com-
puters into “intelligent” agents. By intelligence here we do not necessarily mean an
extraordinary level of smartness shown by superhuman; it rather often involves very
basic problems that humans solve very frequently in their day-to-day life. This can
be as simple as recognizing faces in an image, driving a car, playing a board game, or
reading (and understanding) an article in a newspaper. The intelligent behaviour ex-
hibited by humans when “reading” is one of the main goals for a subfield of AI called
Natural Language Processing (NLP). Natural language 1 is one of the most complex
tools used by humans for a wide range of reasons, for instance to Communicate with
others, to express thoughts, feelings and ideas, to ask questions, or to give instruc-
tions. Therefore, it is crucial for computers to possess the ability to use the same tool
in order to effectively interact with humans.
標(biāo)簽：
Embeddings
Processing
Language
Natural
in
上傳時(shí)間：
2020-06-10
上傳用戶：shancjb
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LED 線陣顯示裝置, 分為 LED 線性旋轉(zhuǎn)顯示主機(jī)和圖文錄入器兩部分。主機(jī)用直流電機(jī)帶動(dòng)由紅綠 LED 組成的線陣旋轉(zhuǎn), 同時(shí)線陣按照時(shí)序依次切換顯示狀態(tài), 在固定區(qū)域利用視覺暫留效果形成 16×16 點(diǎn)陣, 用以顯示圖文;圖文錄入器用 HMI 觸控屏作為人機(jī)交互界面, 實(shí)現(xiàn)圖文錄入和回放功能。主機(jī)與圖文錄入器通過無線通信方式進(jìn)行信息交互,可由圖文錄入器控制主機(jī)切換不同工作任務(wù), 以及改變線陣顯示內(nèi)容。The LED linear array display device is divided into two parts:the one is the main unit used to display content,and the other one is used to input the contents.The main unit is driven by a DC motor to rotate the linear array composed by red and green light emitting diodes.At the same time,the 16×16 dot matrix that switching the display state according to the time sequence on the main unit displays pictures and texts in the fixed area,by using the visual temporary effect.The HMI touch screen is used as human machine interface to realize the function that input and playback pictures and texts.The two parts of the device Communicate with each other through wireless communication.The image and text input controller can control the main unit to switch different tasks and change the content of linear array displayed.
標(biāo)簽：
stc12c5a60s2
單片機(jī)
led
上傳時(shí)間：
2022-03-28
上傳用戶：jiabin
