Orthogonal frequency division multiplexing (OFDM) has been shown to be an effective technique to combat multipath fading in wireless channels. It has been and is going to be used in various wireless communication systems. This book gives a comprehensive introduction on the theory and practice of OFDM for wireless communications.
标签： Multiplexing Orthogonal Frequency Division
上传时间： 2020-05-31
上传用户：shancjb
The ever-increasing demand for private and sensitive data transmission over wireless net- works has made security a crucial concern in the current and future large-scale, dynamic, and heterogeneous wireless communication systems. To address this challenge, computer scientists and engineers have tried hard to continuously come up with improved crypto- graphic algorithms. But typically we do not need to wait too long to find an efficient way to crack these algorithms. With the rapid progress of computational devices, the current cryptographic methods are already becoming more unreliable. In recent years, wireless re- searchers have sought a new security paradigm termed physical layer security. Unlike the traditional cryptographic approach which ignores the effect of the wireless medium, physi- cal layer security exploits the important characteristics of wireless channel, such as fading, interference, and noise, for improving the communication security against eavesdropping attacks. This new security paradigm is expected to complement and significantly increase the overall communication security of future wireless networks.
标签： Communications Physical Security Wireless Layer in
上传时间： 2020-05-31
上传用户：shancjb
This book provides the essential design techniques for radio systems that operate at frequencies of 3 MHz to 100 GHz and which will be employed in the telecommunication service. We may also call these wireless systems, wireless being synonymous with radio, Telecommunications is a vibrant indus- try, particularly on the ‘‘radio side of the house.’’ The major supporter of this upsurge in radio has been the IEEE and its 802 committees. We now devote Ž . an entire chapter to wireless LANs WLANs detailed in IEEE 802.11. We also now have subsections on IEEE 802.15, 802.16, 802.20 and the wireless Ž . Ž metropolitan area network WMAN . WiFi, WiMax,, and UWB ultra wide- . band are described where these comparatively new radio specialties are demonstrating spectacular growth.
标签： Telecommunication Design System Radio for
上传时间： 2020-06-01
上传用户：shancjb
Radio frequency identification (RFID) technology is witnessing a recent explosion of development in both industry and academia. A number of applications include supply chain management, electronic payments, RFID passports, environmental monitoring and control, office access control, intelligent labels, target detection and tracking, port management, food production control, animal identification, and so on. RFID is also an indispensable foundation to realize the pervasive computing paradigm—“Internet of things.” It is strongly believed that many more scenarios will be identified when the principles of RFID are thoroughly understood, cheap components available, and when RFID security is guaranteed.
标签： Architectures NETWORKS SENSOR RFID AND
上传时间： 2020-06-08
上传用户：shancjb
Much has been written concerning the manner in which healthcare is changing, with a particular emphasis on how very large quantities of data are now being routinely collected during the routine care of patients. The use of machine learning meth- ods to turn these ever-growing quantities of data into interventions that can improve patient outcomes seems as if it should be an obvious path to take. However, the field of machine learning in healthcare is still in its infancy. This book, kindly supported by the Institution of Engineering andTechnology, aims to provide a “snap- shot” of the state of current research at the interface between machine learning and healthcare.
标签： Technologies Healthcare Learning Machine
上传时间： 2020-06-10
上传用户：shancjb
Current field forecast verification measures are inadequate, primarily because they compress the comparison between two complex spatial field processes into one number. Discrete wavelet transforms (DWTs) applied to analysis and contemporaneous forecast fields prove to be an insightful approach to verification problems. DWTs allow both filtering and compact physically interpretable partitioning of fields. These techniques are used to reduce or eliminate noise in the verification process and develop multivariate measures of field forecasting performance that are shown to improve upon existing verification procedures.
标签： field forecast verification
上传时间： 2020-07-22
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DisplayPort is an industry standard to accommodate the growing broad adoption of digital display technology within the PC and CE industries.
标签： 接口
上传时间： 2021-10-25
上传用户：刘厚青
This book addresses programmer attitudes, but it’s not some kind of psychology textbook. We’ll investigate many topics, including: Source code presentation Defensive coding techniques How to debug programs effectively Good teamworking skills Managing your source code Take a quick glance through the table of contents to see exactly what’s covered. What is the rationale behind my selection of topics? I’ve been mentor- ing trainee programmers for many years, and these are the topics that have come up time and time again. I’ve also worked in the software factory for long enough to have seen the recurring problems—I address these too. If you can conquer all of these programming demons, you’ll progress from an apprentice coder to a real code craftsman.
标签： excellent practice writing Craft Code code the of
上传时间： 2021-11-09
上传用户：danix800
本文首次设计并验证了基于macom三合一芯片设计的光模块电路,该电路旨在提供一种满足SFF-8472中规定的数字诊断功能的低成本SFP+模块。电路采用激光器驱动、限幅放大器、控制器以及时钟恢复单元集成的单芯片,在保证高精度数字诊断功能基础上,实现了低成本高可靠的特点。该电路在光接收接口组件与激光器驱动和限幅放大器单元的限幅放大器部分之间接入滤波器来提高模块的灵敏度及信号质量。在控制器单元的数字电位器的引脚上采用外加电阻的方式避免出现上电不发光的故障问题。该研究结果为下一代SFP-DD光模块设计与开发工作,奠定了一定的理论与实践基础。This paper designs and validates the optical module circuit based on the MACOM Trinity chip for the first time.This circuit aims to provide a low-cost SFP module which meets the digital diagnosis function specified in SFF-8472.The circuit uses a single chip integrated with laser driver,limiting amplifier,controller and clock recovery unit.On the basis of ensuring high precision digital diagnosis function,it achieves the characteristics of low cost and high reliability.The circuit connects a filter between the optical receiving interface module and the limiting amplifier part of the laser driver and limiting amplifier unit to improve the sensitivity and signal quality of the module.The pin of the digital potentiometer in the controller unit is equipped with an external resistance to avoid the problem of power failure.The research results lay a theoretical and practical foundation for optical module design in high-speed data center.
上传时间： 2022-04-03
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随着电磁阀在工业和日常应用的增多,其功耗越来越被人们所重视。通过对电磁阀驱动电路的研究,设计一套电磁阀节能驱动电路。不仅提高了电磁阀的响应时间,更重要的是降低了功耗,使电磁阀由工作在大电流状态下,变成大电流启动小电流维持的工作状态。减少了由电流过大引起的电磁阀线圈过热,增加了电磁阀的安全性。The power consumption of an electromagnetic valve is drawing increasingly more attentiori as it is widely used in industrial production and daily life. In this study, an energy - saving driving circuit of electromagnetic valves was designed. It can make an electromagnetic valve to start with a high current while work with a low current; thereby the power consumption can be reduced. Besides, it can shorten the response time of an electromagnetic valve and improve the security of the valve.
上传时间： 2022-04-16
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