n the first part of this book, we give an introduction to the basic applications of wireless com- munications, as well as the technical problems inherent in this communication paradigm. After a brief history of wireless, Chapter 1 describes the different types of wireless services, and works out their fundamental differences. The subsequent Section 1.3 looks at the same problem from a different angle: what data rates, ranges, etc., occur in practical systems, and especially, what combination of performance measures are demanded (e.g., what data rates need to be transmitted over short distances; what data rates are required over long distances?) Chapter 2 then describes the technical challenges of communicating without wires, putting special emphasis on fading and co-channel interference. Chapter 3 describes the most elementary problem of designing a wireless system, namely to set up a link budget in either a noise-limited or an interference-limited system. After studying this part of the book, the reader should have an overview of different types of wireless services, and understAND the technical challenges involved in each of them. The solutions to those challenges are described in the later parts of this book.
标签： Communications Wireless Edition 2nd
上传时间： 2020-06-01
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The challenges associated with the design and implementation of Electro- static Discharge (ESD) protection circuits become increasingly complex as technology is scaled well into nano-metric regime. One must understAND the behavior of semiconductor devices under very high current densities, high temperature transients in order to surmount the nano-meter ESD challenge. As a consequence, the quest for suitable ESD solution in a given technology must start from the device level. Traditional approaches of ESD design may not be adequate as the ESD damages occur at successively lower voltages in nano-metric dimensions.
标签： Protection Circuit Device Design ESD and
上传时间： 2020-06-05
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LIKE SO MANY OTHERS , THIS BOOK WAS WRITTEN BECAUSE WE COULDN ’ T FIND ONE LIKE IT . We needed something to hand to all of those people who have come to us asking for “a good book to read on RFID.” When we looked for candidates we found some great books, but most were aimed at electrical engineers or top-level managers, with very little for those of us who are in between. This book is for developers, system and software architects, and project managers, as well as students and professionals in all of the industries impacted by Radio Frequency Identification (RFID) who want to understAND how this technology works. As the title suggests, this book is about RFID in general and not just the most recent developments; however, because so much is going on in the area of RFID for the supply chain and especially the Electronic Product Code (EPC), we have devoted consider- able space to these topics. Regardless of the type of RFID work you may be doing, we think you will find something useful here.
标签： Essentials RFID
上传时间： 2020-06-08
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To a quantum mechanic the whole universe is one godawful big interacting wavefunction ? but to the rest of us, it’s a world full of separate and distinguishable objects that hurt us when we kick them. At a few months of age, human children recognize objects, expect them to be permanent and move continuously, and display surprise when they aren’t or don’t. We associate visual, tactile, and in some cases audible and olfactory sensations with identifiable physical things. We’re hardwired to understAND our environment as being composed of separable things with specific properties and locations. We understAND the world in terms of what was where when.
上传时间： 2020-06-08
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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
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Signals convey information. Systems transform signals. This book introduces the mathe- matical models used to design and understAND both. It is intended for students interested in developing a deep understANDing of how to digitally create and manipulate signals to measure and control the physical world and to enhance human experience and communi- cation.
标签： Interpretation Structure and Signals Systems of
上传时间： 2020-06-10
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以单片机控制A/D转换器TLC549为例,对A/D转换器的主要技术指标进行了分析研究,在Proteus平台下,完成了A/D转换电路的构建,采用器件工作时序方式进行程序编写,借助仿真图表、虚拟仪器等工具对A/D转换的数据进行测量并对失调误差、增益误差、微分非线性、积分非线性和转换时间等重要参数进行了详细分析。结果表明:使用Proteus软件可对A/D转换过程进行定性分析,将抽象的A/D转换器技术指标直观化、形象化展现出来,有助于学生更好地理解A/D转换过程。The main technical indicators of A/D converter were analyzed and studied with an example from A/D converter TLC2543 which is controlled by using SCM.It was completed the construction of the A/D converter circuit under the Proteus software.The programming based on the operation sequence of the chip is put forward.With the aid of the simulation tools such as virtual instrument,simulation charts provided by Proteus,the important parameters of circuit such as offset error,gain error,differential nonlinearity(DNL),integral nonlinearity (INL) and conversion time are analyzed detailedly.Simulation results show that the A/D conversion process can be qualitatively analyzed and visualized the abstract indicators of A/D.The system can help students better to understAND the SCM conversion process.
上传时间： 2022-04-04
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抢答器是一种智力竞赛常用的器件,抢答器的设计方法千差万别,文章利用常用的数字电子器件,设计了八路抢答器电路的设计、仿真及实现的全过程,提出两种可行的设计方案:方案1采用74ls373实现电路锁存,74ls148实现电路编码,74ls74及数码管实现电路显示;方案二采用CD4511BCN和LMC555CM集成电路及数码管实现抢答器的控制和显示。本文设计用的器件简单,容易理解,适用于初学电子技术的人员。Answer scrambler is a common device in intelligence competition, and its design methods vary greatly. This paper designs the whole process of design, simulation and Realization of the circuit of eight-way answer scrambler by using common digital electronic devices, and puts forward two feasible design schemes: scheme 1 uses 74 ls373 to realize circuit latching, 74 ls148 to realize circuit coding,74 ls74 and digital tube to realize circuit. The second scheme uses CD4511 BCN, LMC555 CM integrated circuit and digital tube to control and display the answerer. The device designed in this paper is simple and easy to understAND, and it is suitable for the beginners of electronic technology.
标签： 抢答器
上传时间： 2022-04-05
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PrefaceDuring the past years, there has been a quickly rising interest in radio access technologies for providingmobile as well as nomadic and fixed services for voice, video, and data. The difference indesign, implementation, and use between telecom and datacom technologies is also becoming moreblurred. One example is cellular technologies from the telecom world being used for broadband dataand wireless LAN from the datacom world being used for voice-over IP.Today, the most widespread radio access technology for mobile communication is digital cellular,with the number of users passing 5 billion by 2010, which is more than half of the world’s population.It has emerged from early deployments of an expensive voice service for a few car-borne users,to today’s widespread use of mobile-communication devices that provide a range of mobile servicesand often include camera, MP3 player, and PDA functions. With this widespread use and increasinginterest in mobile communication, a continuing evolution ahead is foreseen.This book describes LTE, developed in 3GPP (Third Generation Partnership Project) and providingtrue 4G broadband mobile access, starting from the first version in release 8 and through the continuingevolution to release 10, the latest version of LTE. Release 10, also known as LTE-Advanced,is of particular interest as it is the major technology approved by the ITU as fulfilling the IMTAdvancedrequirements. The description in this book is based on LTE release 10 and thus provides acomplete description of the LTE-Advanced radio access from the bottom up.Chapter 1 gives the background to LTE and its evolution, looking also at the different standardsbodies and organizations involved in the process of defining 4G. It also gives a discussion of the reasonsand driving forces behind the evolution.Chapters 2–6 provide a deeper insight into some of the technologies that are part of LTE and itsevolution. Because of its generic nature, these chapters can be used as a background not only for LTEas described in this book, but also for readers who want to understAND the technology behind othersystems, such as WCDMA/HSPA, WiMAX, and CDMA2000.Chapters 7–17 constitute the main part of the book. As a start, an introductory technical overviewof LTE is given, where the most important technology components are introduced based onthe generic technologies described in previous chapters. The following chapters provide a detaileddescription of the protocol structure, the downlink and uplink transmission schemes, and the associatedmechanisms for scheduling, retransmission and interference handling. Broadcast operation andrelaying are also described. This is followed by a discussion of the spectrum flexibility and the associated
上传时间： 2022-07-08
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Simulation can provide a lot of information about what the system is doing. We canadd the effect of different element, like Encoder resolution, ADC sampling rate, etc and understAND how does it affect the system. Another benefit is the possibility to slow down the process, to gain insight on what happens of fast systems or, vice versa, speed up slow process.Because National Instruments is a unique company in the fact the we provide a fullhardware solution couple with a full development platform, we can use this tools in very particular ways For example, it is possible to combine the LabVIEW Control Design and Simulation Module along with the FPGA module to quickly prototype a controller. One of the main benefits of this approach is that there is no need to compile the FPGA code, which allows for a quick algorithm design turnaround and debugging.
标签： pid控制
上传时间： 2022-07-20
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