Once upon a time, cellular wireless networks provided two basic services: voice telephony and low-rate text messaging. Users in the network were separated by orthogonal multiple access schemes, and cells by generous frequency reuse patterns [1]. Since then, the proliferation of wireless services, fierce competition, andthe emergenceof new service classes such as wireless data and multimediahave resulted in an ever increasing pressure on network operators to use resources in a moreefficient manner.In the contextof wireless networks,two of the most common resources are power and spectrum—and, due to regulations, these resources are typically scarce. Hence, in contrast to wired networks, overprovisioning is not feasible in wireless networks.
标签: Maximization Nonconvex Wireless Utility Systems in
上传时间: 2020-06-01
上传用户:shancjb
Two of the major developments reshaping the telecommunications landscape are mobile wireless connectivity and the migration of voice telephone services to IP technology. Those two ideas come together in networks that carry voice services over a wireless LAN (VoWLAN). The purpose of this text is to provide network professionals with the technical background and practical guidance needed to deploy these networks successfully.
上传时间: 2020-06-01
上传用户:shancjb
Wavelength division multiplexing (WDM) refers to a multiplexing and transmission scheme in optical telecommunications fibers where different wavelengths, typically emitted by several lasers, are modulated independently (i.e., they carry independent information from the transmitters to the receivers). These wavelengths are then multiplexed in the transmitter by means of passive WDM filters, and likewise they are separated or demultiplexed in the receiver by means of the same filters or coherent detection that usually involves a tunable local oscillator (laser).
标签: Multiplexing Wavelength Division
上传时间: 2020-06-01
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The use of optical free-space emissions to provide indoor wireless commu- nications has been studied extensively since the pioneering work of Gfeller and Bapst in 1979 [1]. These studies have been invariably interdisciplinary in- volving such far flung areas such as optics design‚ indoor propagation studies‚ electronics design‚ communications systems design among others. The focus of this text is on the design of communications systems for indoor wireless optical channels. Signalling techniques developed for wired fibre optic net- works are seldom efficient since they do not consider the bandwidth restricted nature of the wireless optical channel.
标签: Communication Wireless Optical Systems
上传时间: 2020-06-01
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This text, ESD Basics: From Semiconductor Manufacturing to Product Use was initiated on the need to produce a text that addresses fundamentals of electrostatic discharge from the manufacturing environment to today’s products. As the manufacturing world evolves, semi- conductor networks scale, and systems are changing, the needs and requirements for reliabi- lity and ESD protection are changing. A text is required that connects basic ESD phenomena to today’s real world environment.
上传时间: 2020-06-05
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As a student I did my best to avoid text books – a strange statement for a Professor to make and one that I should clarify before you put this book down; I did my best to avoid text books that did not help me.
标签: Microdevices Ceramic Thick Films MEMS for and
上传时间: 2020-06-06
上传用户:shancjb
In writing this text my intention was to collect together in a single place practical predictive modeling techniques, ideas and strategies that have been proven to work but which are rarely taught in business schools, data science courses or contained in any other single text.
标签: Predictive Techniques Modeling Applied 92
上传时间: 2020-06-06
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The first edition as well as its forerunner of Kuffel and Abdullah published in 1970 and their translations into Japanese and Chinese languages have enjoyed wide international acceptance as basic textbooks in teaching senior under- graduate and postgraduate courses in High-Voltage Engineering. Both texts have also been extensively used by practising engineers engaged in the design and operation of high-voltage equipment. Over the years the authors have received numerous comments from the text’s users with helpful suggestions for improvements. These have been incorporated in the present edition. Major revisions and expansion of several chapters have been made to update the continued progress and developments in high-voltage engineering over the past two decades.
标签: Engineering Voltage High
上传时间: 2020-06-07
上传用户:shancjb
Software-defined radios (SDRs) have been around for more than a decade. The first complete Global Positioning System (GPS) implementation was described by Dennis Akos in 1997. Since then several research groups have presented their contributions. We therefore find it timely to publish an up-to-date text on the sub- ject and at the same time include Galileo, the forthcoming European satellite- based navigation system. Both GPS and Galileo belong to the category of Global Navigation Satellite Systems (GNSS).
标签: A_Software-Defined_GPS_and_Galile o_Receiver
上传时间: 2020-06-09
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If one examines the current literature on GPS receiver design, most of it is quite a bit above the level of the novice. It is taken for granted that the reader is already at a fairly high level of understanding and proceeds from there. This text will be an attempt to take the reader through the concepts and circuits needed to be able to understand how a GPS receiver works from the antenna to the solution of user position.
标签: Fundamentals_of_Global_Positionin g_System
上传时间: 2020-06-09
上传用户:shancjb