无线通信毕业设计外文翻译

合集下载

通信工程毕业设计外文翻译--下一代无线宽带的目标(4G—5G)

通信工程毕业设计外文翻译--下一代无线宽带的目标(4G—5G)

附录一、英文原文:Goals Of True Broad band’s Wireless Next Wave(4G-5G)K.R.Santhi,Prof.V.K.Srivastava,G.SenthilKumaran,Eng. Albert Butare.Kigali Institute of Science Technology and Management (KIST),B.P.3900, Kigali,Rwanda.AbstractAs access technology increases, voice, video,multimedia, and broadband data services are becomingintegrated into the same network. Fourth Generation (4G)is the next generation of wireless networks that will replacethird Generation (3G) networks sometimes in future. 4G isintended to provide high speed, high capacity, low cost perbit, IP based services.4G is all about an integrated, globalnetwork that’s based on an open system approach. The goalof 4G i s to “replace the current proliferation of core cellularnetworks with a single worldwide cellular core networkstandard based on IP for control, video, packet data andV oIP. But while 3G haven’t quite arrived, researchers wantto contribute their ideas to the development of an as-yetundefined "wireless world" that could become operationalby around 2010. This paper deals with the fundamentalsand issues of networks, technologies, spectrum, standards,terminals, services of 4G and about the visions that thenetwork operators and service providers see for theevolution of 4G mobile systems and where is future researchfrom their perspective necessary?Keywords:Wireless, 4G, W-OFDM, MC-CDMA, LAS-CDMA,UWB.I. INTRODUCTIONWhile carriers and handset manufacturers obviously havetheir hands full with 3G, some companies are alreadylooking beyond this next generation of wirelesstechnology and networks. 4G is simply an initiative byacademic R&D labs to move beyond the limitations andproblems of 3G which is having trouble getting deployedand meeting its promised performance and throughput.While this 3G has not completely reached researchers andvendors are expressing growing interest in 4G why? Twomain areas are addressed in these initiatives: An increaseof capacity in the radio link and seamless mobility acrossheterogeneous access networks. Section 2 discusses aboutthe issues of 3G that has created interest towards 4Gdevelopments.Section 3 about evolution and comparison,Section 4 describes about the goals and the vision, section5 explains about some of the technologies for 4G, and inother following sections the applications, the research andother issues for 4G developments are discussed.II. WHY THE LEAP TOWARDS 4G?3G networks are in a very painful phase of theirdevelopment, with early trials yielding disappointingresults, costs ballooning, technical glitches, and networkoperators being forced to deflate expectations based onunrealistic hype. Despite the hype surrounding thehigher-speed 3G mobile networks now underconstruction, the reasons for the leap towards 4G are:A. PerformanceIndustry skeptics say that users will not be able to takeadvantage of rich multimedia content across wirelessnetworks with 3G. 4G communications will featureextremely high-quality video equal to that of high-definitiontelevision. In addition, it will enable wirelessdownloads at speeds exceeding 100 Mbps, about 260times than 3G wireless network.B. InteroperabilityThere are multiple standards for 3G making it difficult toroam and interoperate across networks. We need a globalstandard that provides global mobility and serviceportability so that service provider would no longer bebound by single-system vendors of proprietaryequipment.C. Networking3G are based on primarily a wide-area concept. We needhybrid networks that utilize both wireless LAN (hot spot)concept and cell or base-station WAN design. With 4G,the world would have base stations everywhere, ensuringphone usersconnection to a high-speed networkanywhere, anytime.D. BandwidthWe need wider bandwidth and higher bit rates. The 4Gtechnology, with its transmission speeds of more than 20mbps, would offer high-bandwidth services within thereach of LAN "hotspots," installed in offices,homes,coffee shops,and airport lounges. Away from thesehotspots, customers could connect to souped-up 2Gnetworks for voice and rudimentary data coverage.E. TechnologyUnlike 3G, 4G will more resemble a conglomeration ofexisting technologies rather than an entirely newstandard. Analysts define 4G as a seamless combinationof existing 2G wireless networks with local-areanetworks (LANs) or Bluetooth.F. ConvergenceConvergence involves more than mere technology; it is acoming together of services and markets.We need allnetwork that utilizes IP in its fullest form with convergedvoice and data capability,which the 4G will achieve.G. Cost4G systems will prove far cheaper than 3G, since theycan be built atop existing networks and won't requireoperators to completely retool and won't require carriersto purchase costly extra spectrum.Also an open systemIP wireless environment would probably further reducescosts for service providers by ushering in an era of realequipment interoperability.H. ScalabilityScalability, or the ability to handle increasing numbers ofusers and diversity of services, is more challenging withmobile networks."Design for Scalability," includesinformation that can help you meet changing usagedemands.Because an all IP core layer of 4G is easilyscalable, it is ideally suited to meet this challenge.III.EVOLUTION AND COMPARISON OFBROADBANDWIRELESS1) First Generation (1G):1G wireless mobilecommunication systems, was introduced in the early1980s.1G wireless was analog and supported the firstgeneration of analog cell phones.They include asignaling protocol known as SS7 (Signaling System 7).2) Second Generation (2G): 2G systems, fielded in thelate 1980s, were intended primarily for voicetransmission and was all about digital PCS.3) Third Generation (3G): 3G in wireless will be adeliberate migration to faster, data-centric wirelessnetworks.The immediate goal is to raise transmissionspeeds from 125kbps to 2M bit/sec.4) Fourth Generation (4G): In reality, as of first half of2002, 4G is a conceptual framework for or a discussionpoint to address future needs of a universal high speedwireless network that will interface with wirelinebackbone network seamlessly.IV. THE 4G NETWORK THAT THECELL-HEADSDREAM ABOUT4G can be imagined of as an integrated wireless systemthat enables seamless roaming between technologies.Auser can be operating in cellular technology network andget handed over to a satellite-based network and back to afixed wireless network, depending upon the networkcoverage and preference of charging.A. The GoalsOpen Mobile Alliance’s (OMA) main goal is to makesure different wireless services and devices worktogether, and across countries, operators, and mobileterminals.Other plans in the group's charter include:•Deliver open standards and specifications based onmarket and customer requirements.• Create and promote a common industry view on anarchitectural framework.• Help consolidate standards groups and work inconjunction with other existing standardsorganizations and groups.B. The Composite Vision• 20 Mbps data rates• Streaming Audio/Video• Asymmetric Access• Adaptive Modulation/Coding• Dynamic packet assignment• Smart/Adaptive antennas supportedC. 4G Network Architecture“4G” wireless networks can be realized with an IP-basedcore network for global routing along with morecustomized local-area radio access networks that supportfeatures such as dynamic handoff and ad-hoc routing aswell as newer requirements such as self-organization,QoS, multicasting, content caching, etc..In 4G LANs will be installed in trains and trucks as wellas buildings, or even just formed on an ad-hoc basisbetween random collections of devices that happen tocome within radio range of one other. Routing in suchnetworks will depend on new architectures, already underdevelopment by the IEEE and a European project calledMobile IP Network Developments (MIND).D. The working PrincipleIn 4G-style mobile IP, each cell phone is assigned apermanent "home" IP address, along with a "care-of"address that represents its actual location.When acomputer somewhere on the Internet wants tocommunicate with the cell phone, it first sends apacketto the phone's home address.A directory server on thehome network forwards this to the care-of address via atunnel, as in regular mobile IP. However, the directoryserver also sends a message to the computer informing itof the correct care-of address, so future packets can besent directly.This should enable TCP sessions and HTTPdownloads to be maintained as users move betweendifferent types of networks.Because of the manyaddresses and the multiple layers of subnetting, IPv6 isneeded for this type of mobility.V. TECHNOLOGIES THAT SUPPORT 4GThe revolution in 4G will be the optical networking, thenew air interface, the portable device etc.A. The Transmission Protocols1) OFDM: OFDM is a digital modulation technology inwhich in one time symbol waveform, thousands oforthogonal waves are multiplexed.This is good for highbandwidth digital data transition.2) W-OFDM: W-OFDM enables data to be encoded onmultiple high-speed radio frequencies concurrently. Thisallows for greater security, increased amounts of databeing sent, and the industry’s most efficient use ofbandwidth.W-OFDM enables the implementation of lowpower multipoint RF networks that minimize interferencewith adjacent networks.This enables independentchannels to operate within the same band allowingmultipoint networks and point-to-point backbone systemsto be overlaid in the same frequency band.3) MC-CDMA : MC-CDMA is actually OFDM with aCDMA overlay.Similar to single-carrier CDMA systems,the users are multiplexed with orthogonal codes todistinguish users in (multi-carrier) MC-CDMA.Howeverin MC-CDMA, each user can be allocated several codes,where the data is spread in time or frequency.4) LAS-CDMA:LinkAir Communications is developer of LAS-CDMA(Large Area Synchronized Code Division MultipleAccess) a patented 4G wireless technology. LAS-CDMAenables high-speed data and increases voice capacity andlatest innovative solution, CDD, merges the highlyspectral efficient LAS-CDMA technology with thesuperior data transmission characteristics of TDD.Thisresulting combination makes CDD the most spectrallyefficient, high-capacity duplexing system available today.B. The Radio Interface-UWB RadioTo make 4G really work carries will need to migrate toUltra Wideband (UWB) technology.UWB radiowill deliver essential new wireless andwired bandwidth inexpensively, without using preciousand scarce radio frequencies.Instead,digital video, voiceand data are enabled using modulated pulses of energythat peacefully co-exist alongside traditionalcommunications.UWB radio solves the multipath fadingissues and is 1,000% more process efficient than CDMA.C. The Network-LMDSLocal multipoint distribution system (LMDS) is thebroadband wireless technology used to deliver voice,data, Internet, and video services in the 25-GHz andhigher spectrum (depending on licensing).The acronymLMDS is derived from the following: L(local)—denotes that propagation characteristics ofsignals in this frequency range limit the potentialcoverage area of a single cell site;M (multipoint)—indicates that signals are transmitted ina point-to-multipoint or broadcast method;D (distribution)—refers to the distribution of signals,which may consist of simultaneous voice, data, Internet,and video traffic;S (service)—implies the subscriber nature of therelationship between the operator and the customer.VI. POTENTIAL APPLICATIONS OF 4G1) Virtual Presence: 4G system gives mobile users a"virtual presence" -- for example, always-on connectionsthat keep people involved in business activities regardlessof whether they are on-site or off.2)Virtual navigation:A remote database contains thegraphical representation of streets, buildings, andphysical characteristics of a large metropolis.Blocks ofthis database are transmitted in rapid sequence to avehicle, where a rendering program permits the occupantsto visualize the environment ahead.3) Tele-medicine: 4G will support remote healthmonitoring of patients.For e.g. the paramedic assistingthe victim of traffic accident in a remote location mustaccess medical records and may need videoconferenceassistance from a surgeon for an emergency intervention.The paramedic may need to relay back to the hospital thevictim's x-rays taken locally.4)Tele-geoprocessing applications:Thecombination of geographical information systems (GIS),global positioning systems (GPS), and high-capacitywireless mobile systems will enable a new type ofapplication referred to as tele-geoprocessing.Queriesdependent on location information of several users, inaddition to temporal aspects have many applications.5) Crisis-management applications:Naturaldisasters can affect the entire communicationsinfrastructure is in disarray.Restoring communicationsquickly is essential.With wideband wireless mobilecommunications Internet and video services, could be setup in hours instead of days or even weeks required forrestoration of wireline communications.6) Education :Educational opportunities availableon the internet, for individuals interested in life-longeducation, will be unavailable to client in remote areasbecause of the economic unfeasibility of providingwideband wireline internet access.4G wirelesscommunications provides a cost-effective alternative inthese situations.VII. ROLE OF THE WIRELESSINDUSTRYRECOMMENDATIONSWe are bringing to the attention of professionalsfollowing issues and problems that must be analyzed andresolved:1)Standardization: Standardization of wireless networksin terms of modulation techniques, switching schemesand roaming is an absolute necessity for 4G. We mustpay more attention to general meaning advancedtechnologies.2) Lower Price Points Only Slightly Higher thanAlternatives: The business visionaries should do someeconomic modeling before they start 4G hype. Theyshould understand that 4G data applications likestreaming video must compete with very low costwireline applications.3) More Coordination Among Spectrum RegulatorsAround the World:We must demand almost freespectrum NOT necessarily unlicensed Spectrumregulation bodies must get involved in guiding theresearchers by indicating which frequency band might beused for 4G.4) Regulatory frameworks:Policy and RegulatoryEnvironment which Provides Transparency, Certaintyand a Level Playing Field are necessary. The mostimportant thing is that we should recognize thatregulatory framework is as much an evolving matter astechnology, and be prepared to meet changes with anopen-minded and pragmatic attitude, always keeping theinterests of the industry and consumers in mind.5) More Academic Research:Universities must spendmore effort in solving fundamental problems in radiocommunications (especially multiband and widebandradios, intelligent antennas and signal processing).6) Voice-independent Business Justification Thinking:Business and Technology executives should not bias theirbusiness models by using voice channels as economicdeterminant for data applications.V oice has a built-indemand limit - data applications do not.7) Integration Across Different Network Topologies:Network architects must base their architecture on hybridnetwork concepts thatintegrates wireless wide areanetworks, wireless LANS (IEEE 802.11a, IEEE 802.11b,IEEE 802.11g, IEEE 802.15 and IEEE 802.16), Bluetoothwith fiber-based Internet backbone.Broadband wirelessnetworks must be a part of this integrated networkarchitecture.8) Non-disruptive Implementation: Upgrading from 3G to 4G is expected to be seamless to end-users with nodevice upgrades required.VIII. DEVELOPMENTS IN 4GAT&T is combining W-OFDM and EDGE technologies,to provide broadband mobile downlink access at peakrates of up to 10 Mbps while EDGE offers uplink accessat 384 Kbps with an 800KHz bandwidth in a high-mobilityenvironment.Sun Microsystems Laboratories are building 4G wirelesstechnologies that promise tointegrate voice and web datain an IP-based mobile communications.The Government of Karnataka in India has signed a MoUwith Charmed Technologies Inc from Beverly Hills,California and Software Technology Parks of India inKarnataka to develop 4G wireless technology. Theproject plan to use wireless technology based on theIEEE802.11a and IEEE802.11b standards for wirelessLAN for the underlying network is designed to support adata rate of up to 11Mbps and 54Mbps respectively. Thegoal is to get 6 billion people connected to the wirelessInternet by 2010.NTT DoCoMo and Hewlett-Packard Company &MOTOmediacollaboration will explore new mobile serviceconcepts in which people, places and things will be ableto interact, thereby bridging the real and the cyber world.MOTO-media is expected to enable high performancestreaming of multimedia content to mobile users.DoCoMo and HP aim to nish the shared study of basictechnology by 2003 and hope to push for 4G in 2006.IX. SUGGESTIONSWe would like to give the following suggestions for thedevelopment of 4G mobile technologies:1. Technologies like 4G must be developed to integrateinto a more flexible network that grow within thenetwork so that we don't have to scarp the old network toimplement the next generation, the generations to come.2. The very big challenge for developing a technology isproper human resource for building high quality systems.Big organization, which is engaged in software andsystem development, should rapidly go for tie-ups witheducational institutes for better manpower and knowledgemanagement.3. We talk about mobile multimedia that 4G will supportbut in reality people are not going to watch TV whilethey walk down the street. Likewise people will not buyCoca Cola at vending machines with a cell phone. Quitoften services conjured up by the engineering side of thevendor organizations has little to do with the reality. Sowireless industry should ponder well about marketdemand and invest money so that they will not be at loss.X.CONCLUSION4G should make a significant difference and addperceived benefit to an ordinary person’s life over 3G.We should drop the 2.5G, 3G, 4G speak altogether wherean additional “G” means merely an increase in capacity.What really means something for the users are newservices, integration of services, applications etc. Ourgoal is to struggle to get a “G”eneration of standards sothat we can take our phone anywhere in the world andaccess any service or communicate with any other userany way we want that will offer connectivity soinexpensively. In short, 4G or WWWW (World WideWireless web) should be a more intelligent technologythat interconnects the entire world without limits.二、英文翻译:下一代无线宽带的目标(4G—5G)摘要:随着接入技术的增长,语音、视频、多媒体和宽带数据业务正在集成到同一个网络中去。

无线通信英文版课程设计 (2)

无线通信英文版课程设计 (2)

无线通信英文版课程设计IntroductionWireless communication has been an important research field in the past few decades. With the development of modern communication technology, the demand for wireless communication technology has increased rapidly. Wireless communication can be defined as the transmission of information from one point to another without the use of physical connections such as wires or cables. It is widely used in mobile communication, satellite communication, and internet communication.This course ms to provide an introduction to the fundamental concepts of wireless communication. The course will cover various topics such as wireless channel models, modulation and demodulation techniques, multiple access schemes, wireless networking and wireless security. The course will also include an overview of the current trends and future directions of wireless communication.Course ObjectivesThe objectives of this course are as follows:1.To understand the fundamental concepts of wirelesscommunication2.To become familiar with wireless channel models and theirproperties3.To learn various modulation and demodulation techniques usedin wireless communication4.To understand multiple access schemes in wirelesscommunication5.To learn wireless networking techniques and protocols6.To gn knowledge about wireless security and privacyCourse DesignThis course will be divided into the following modules:Module 1: Introduction to Wireless CommunicationThis module will provide an introduction to wireless communication, its applications and the challenges associated with it. The module will cover the following topics:•Introduction to wireless communication•Wireless channel models•The impact of wireless channel conditions on communication performance•Overview of modulation and demodulation techniques Module 2: Multiple Access TechniquesThis module will cover the multiple access techniques used in wireless communication. The module will cover the following topics: •Frequency division multiple access (FDMA)•Time division multiple access (TDMA)•Code division multiple access (CDMA)•Orthogonal frequency division multiple access (OFDMA)Module 3: Wireless NetworkingThis module will introduce wireless networking techniques and protocols used in wireless communication. The module will cover the following topics:•Wireless LANs (WLAN)•Bluetooth technology•ZigBee technology•Wireless sensor networks (WSN)Module 4: Wireless SecurityThis module will discuss the security and privacy issues in wireless communication. The module will cover the following topics:•Wireless security threats and attacks•Cryptography and encryption techniques used in wireless communication•Security protocols in wireless communicationCourse AssessmentThe assessment of this course will depend on the following:•Regular attendance and participation in lectures and discussions•Assignment completion and submission•Midterm examination•Final examinationConclusionIn conclusion, this course ms to provide the students with the basic knowledge and techniques used in wireless communication. The course will enable the students to understand the fundamental concepts of wireless communication, and its applications. The course will also provide an overview of the current trends and future directions of wireless communication.。

本科毕业论文中英文翻译--Wireless-Communications无线通信【范本模板】

本科毕业论文中英文翻译--Wireless-Communications无线通信【范本模板】

Wireless Communications*byJoshua S。

Gans,Stephen P。

King and Julian Wright1. IntroductionIn 1895, Guglielmo Marconi opened the way for modern wireless communications by transmitting the three—dot Morse code for the letter ‘S’ over a distance of th ree kilometers using electromagnetic waves。

From this beginning,wireless communications has developed into a key element of modern society. From satellite transmission, radio and television broadcasting to the now ubiquitous mobile telephone,wireless communications has revolutionized the way societies function.This chapter surveys the economics literature on wireless communications。

Wireless communications and the economic goods and services that utilise it have some special characteristics that have motivated specialised studies。

First, wireless communications relies on a scarce resource –namely,radio spectrum –the property rights for which were traditionally vested with the state. In order to foster the development of wireless communications (including telephony and broadcasting)those assets were privatised。

通信工程毕业论文外文翻译

通信工程毕业论文外文翻译

多次反射罐方案DSA用于多跳认知无线电网络的分布式网络编码控制信道Alfred Asterjadhi等著1 前言大多数电磁频谱由政府机构长期指定给公司或机构专门用于区域或国家地区。

由于这种资源的静态分配,许可频谱的许多部分在许多时间和/或位置未使用或未被充分利用。

另一方面,几种最近的无线技术在诸如IEEE802.11,蓝牙,Zigbee之类的非许可频段中运行,并且在一定程度上对WiMAX进行操作;这些技术已经看到这样的成功和扩散,他们正在访问的频谱- 主要是2.4 GHz ISM频段- 已经过度拥挤。

为了为这些现有技术提供更多的频谱资源,并且允许替代和创新技术的潜在开发,最近已经提出允许被许可的设备(称为次要用户)访问那些许可的频谱资源,主要用户未被使用或零星地使用。

这种方法通常被称为动态频谱接入(DSA),无线电设备发现和机会性利用未使用或未充分利用的频谱带的能力通常称为认知无线电(CR)技术。

DSA和CR最近都引起了无线通信和网络界的极大关注。

通常设想两种主要应用。

第一个是认知无线接入(CW A),根据该认知接入点,认知接入点负责识别未使用的许可频谱,并使用它来提供对次用户的接入。

第二个应用是我们在这个技术中研究的应用,它是认知自组织网络(CAN),也就是使用用于二级用户本身之间通信的无许可频谱,用于诸如点对点内容分发,环境监控,安全性等目的,灾难恢复情景通信,军事通信等等。

设计CAN系统比CW A有更多困难,主要有两个原因。

第一是识别未使用的频谱。

在CW A中,接入点的作用是连接到互联网,因此可以使用简单的策略来推断频谱可用性,例如查询频谱调节器在其地理位置的频谱可用性或直接与主用户协商频谱可用性或一些中间频谱经纪人另一方面,在CAN中,与频谱调节器或主要用户的缺乏直接通信需要二级用户能够使用检测技术自己识别未使用的频谱。

第二个困难是辅助用户协调媒体访问目的。

在CW A中存在接入点和通常所有二级用户直接与之通信(即,网络是单跳)的事实使得直接使用集中式媒体接入控制(MAC)解决方案,如时分多址(TDMA)或正交频分多址(OFDMA)。

无线通信原理与应用英文版第二版课程设计 (2)

无线通信原理与应用英文版第二版课程设计 (2)

Wireless Communication Principles and Applications Course Design: Second Edition in English IntroductionWireless communication has become a ubiquitous technology almost in every facet of life. It allows people to communicate with each other, devices to be connected wirelessly, and many more. Studying wireless communication principles and applications is an essential subject in electrical engineering. This course design ms to provide students with hands-on experience in designing and implementing wireless communication systems.Learning ObjectivesBy the end of this course, students will be able to: - Understandthe fundamentals of wireless communication - Design and implement wireless communication systems - Analyze and evaluate wireless communication systems - Apply knowledge and skills to solve practical problems - Collaborate and communicate effectively within a team Course OutlineWeek 1: Introduction to Wireless Communication•History of wireless communication•Basic concepts and terminology•Frequency bands and standardsWeek 2: Signal Transmission and Propagation•Electromagnetic waves and their properties•Transmission mediums and propagation models•Antenna theory and designWeek 3: Modulation Techniques•Analog and digital modulation techniques•Amplitude modulation and demodulation•Frequency modulation and demodulationWeek 4: Wireless Networks•Wireless communication standards and protocols•Network topologies and architectures•Wireless local area networks (WLAN) and their applications Week 5: Cellular Networks•Cellular network structure and components•Frequency reuse and cell planning•Mobile communication generations and their evolutionWeek 6: Wireless Communication Security•Security threats and vulnerabilities in wireless communication•Encryption and decryption techniques•Authentication and access control mechanismsWeek 7: Wireless Communication Applications•Internet of Things (IoT) and Smart Cities•Wireless sensor networks•Wireless power transfer and wireless chargingWeek 8: Course Project•Students will work in groups to design and implement a wireless communication system•The project includes system design, hardware and software implementation, testing and evaluation, and project report writing.AssessmentAssessment will be based on the following: - Class participation: 10% - Assignments and quizzes: 40% - Final project: 50%ConclusionThis course design has highlighted the essential topics thatstudents will learn during this Wireless communication principles and applications course. It provides a comprehensive guide on how to design and implement wireless communication systems, which is a fundamental course for electrical engineering students.。

通信工程毕业设计 外文翻译

通信工程毕业设计 外文翻译

东华理工大学长江学院毕业设计外文翻译学生姓名:张伟学号:09323119专业:信息工程系别:信息工程指导教师:谌洪茂职称:讲师二0一三年六月五日OriginalOptical Fiber CommunicationsThe General System Communication may be broadly defined as the transfer of information from one point to another. When the information is to be conveyed over any distance a communication system is usually required. Within a communication system the information transfer is frequently achieved by superimposing or modulating the information onto an electromagnetic wave which acts as a carrier for the information signal. This modulated carrier is then transmitted to the required destination where it is received and the original information signal is obtained by demodulation. Sophisticated techniques have been developed for this process by using electromagnetic carrier waves operating at radio frequencies as well as microwave and millimeter w ave frequencies. However, ‘communication’ may also be achieved by using an electromagnetic carrier which is selected from the optical range of frequencies.An optical fiber communication system is similar in basic concept to any type of communication system.The communication system therefore consists of a transmitter or modulator linked to the information source, the transmission medium,and a receiver or demodulator at the destination point. In electrical communications the information source provides an electrical signal, usually derived from a message signal which is not electrical (e.g. sound), to a transmitter comprising electrical and electronic components which converts the signal into a suitable form for propagation over the trans-mission medium. This is often achieved by modulating a carrier, which, as mentioned previously, may be an electromagnetic wave. The transmission medium can consist of a pair of wires, a coaxial cable or a radio link through free space down which the signal is transmitted to the receiver, where it is transformed into the original electrical information signal (demodulated) before being passed to the destination.However, it must be noted that in any transmission medium the signal is attenuated, or suffers loss, and is subject to degradations due to contamination by random signals and noise, as well as possible distortions imposed by mechanisms within the medium itself. Therefore, in any communication system there is a maximum permitted distance between the transmitter and the receiver beyond which the system effectively ceases to give intelligible communication. For long-haul applications these factors necessitate the installation of repeaters or line amplifiers atintervals,both to remove signal distortion and to increase signal level before transmission is continued down the link.For optical fiber communications system shown in Figure (a) may be considered in slightly greater detail, as given in Figure (b).Fig(a) The general communication system(b)The optical fiber communication systemIn this case the information source provides an electrical signal to a transmitter comprising an electrical stage which drives an optical source to give modulation of the light wave carrier. The optical source which provides the electrical–optical conversion may be either a semiconductor laser or light-emitting diode (LED). The transmission medium consists of an optical fiber cable and the receiver consists of an optical detector which drives a further electrical stage and hence provides demodulation of the optical carrier. Photodiodes (p–n, p–i–n or avalanche) and, in some instances, phototransistors and photoconductors are utilized for the detection of the optical signal and the optical–electrical conversion. Thus there is a requirement for electrical interfacing at either end of the optical link and at present the signal processing is usually performed electrically.The optical carrier may be modulated using either an analog or digital information signal. In the system shown in Figure (b) analog modulation involves the variation of the light emitted from the optical source in a continuous manner. Withdigital modulation,however, discrete changes in the light intensity are obtained (i.e. on–off pulses).Although often simpler to implement, analog modulation with an optical fiber communication system is less efficient, requiring a far higher signal-to-noise ratio at the receiver than digital modulation. Also, the linearity needed for analog modulation is not always provided by semiconductor optical sources, especially at high modulation frequencies. For these reasons,analog optical fiber communication links are generally limited to shorter distances and lower bandwidth operation than digital links.Figure (c) shows a block schematic of a typical digital optical fiber link. Initially, the input digital signal from the information source is suitably encoded for optical transmission. The laser drive circuit directly modulates the intensity of the semiconductor laser with the encoded digital signal. Hence a digital optical signal is launched into the optical fiber cable. The avalanche photodiode (APD) detector is followed by a front-end amplifier equalizer or filter to provide gain as well as linear signal processing and noise bandwidth reduction.Fig(c)A digital optical fiber link using a semiconductor laser source and an avalanche photodiode(APD) detectorFinally, the signal obtained is decoded to give the original digital information. However, at this stage it is instructive to consider the advantages provided by light wave communication via optical fibers in com-parison with other forms of line and radio communication which have brought about the extensive use of such systems in many areas throughout the world.译文光纤通信一般来说把信息从一点传送到另一点就称为通信。

无线局域网毕业论文中英文对照资料外文翻译文献

无线局域网毕业论文中英文对照资料外文翻译文献

无线局域网毕业论文中英文对照资料外文翻译文献中英文对照资料外文翻译文献WLANWhy use WLANFor one of the main local area network management, for the laying of cables, or check the cable is disconnected this time-consuming work, it is easy to upset, not easy to break in a short time to find out where. Furthermore, for the business and application environment constantly updating and development of enterprise network must be matched with the original re-layout, need to re-install the network lines, although the cable itself is not expensive, but requested the technical staff to the high cost of wiring, especially the old building, wiring project costs even higher. Therefore, the construction of wireless local area network has become the best solution.What conditions need to use WLANWLAN is not limited to alternative local area network, but to make up for lack of wired local area networks, in order to achieve the purpose of extending the network, the following circumstances may have wireless local area network.●no fixed workplace users●wired local area network set up by the environmental constraints●As a wired local area network backup systemWLAN access technologyCurrently manufacturers in the design of wireless local area network products, there are quite a variety of access design methods can be divided into three categories: narrowband microwave, spread spectrum (Spread Spectrum) technology, andinfrared have their advantages and disadvantages, limitations, and more, followed by detailed discussion of these techniques. (Infrared) technology, each technique has their advantages and disadvantages, limitations, and more, followed by detailed discussion of these techniques.Technical requirementsAs wireless local area network needs to support high-speed, burst data services, need to be addressed in the indoor use of multipath fading, as well as issues such as crosstalk subnets. Specifically, wireless local area network must achieve the following technical requirements:1)Reliability: Wireless LAN system packet loss rate should be lower than 10-5,the error rate should be lower than 10-8.2)Compatibility: For indoor use of wireless local area network, so as far aspossible with the existing wired LAN network operating system and networksoftware compatible.3)Data rate: In order to meet the needs of local area network traffic, wirelessLAN data transfer rate should be more than 1Mbps.4)The confidentiality of communications: As the data transmitted in the air viawireless media, wireless local area networks at different levels must takeeffective measures to improve communication security and data security.5)Mobility: support for all mobile networks or semi-mobile network.6)Energy Management: When receiving or sending data to the site when themachine is in sleep mode, when activated again when the data transceiver toachieve the savings in power consumption.7)small size and low price: This is the key to the popularity of wireless local areanetwork can be.8)Electromagnetic environment: wireless LAN should consider thehumanbodyand the surrounding electromagnetic environment effects.AndroidGoogle Android is a Linux-based platform for developing open-source phone operating system (registered trademark in China called "Achi;). It includes operating systems, user interface and applications - mobile phone work required by the software, but there is no past, the exclusive right to impede innovation and barriers to mobile industry, called mobile terminal is the first to create a truly open and complete mobile software. Google and Open Handset Alliance to develop the Android, the alliance by including China Mobile, Motorola, Qualcomm and T-Mobile, including more than 30 technology and the composition of a leader in wireless applications. Google with operators, equipment manufacturers, developers and other interested parties to form deep-level partnerships, hoping to establish a standardized, open software platform for mobile phones in the mobile industry to form an open ecosystem .It uses software stack layers (software stack, also known as the software stack) architecture, is divided into three parts: thecore of the underlying Linux-based language developed by the c, only basic functions. Middle layer consists of library. Library and Virtual Machine Virtual Machine, developed by the C +. At the top are a variety of applications, including the call procedures, SMS procedures, application software is developed by the companies themselves to write java.To promote this technology, Google, and dozens of other phone company has established the Open Handset Alliance (Open Handset Alliance).Characteristic●application framework to support component reuse and replacement●Dalvik virtual machine specifically for mobile devices i s optimized●Internal integrated browser, the browser-based open-source WebKit engine●optimization of 2D and 3D graphics library includes graphics library, 3Dgraphics library based on OpenGL ES 1.0 (hardware-accelerated optional)●# SQLite for structured data storage●Multimedia support includes the common audio, video and static image fileformats (such as MPEG4, H.264, MP3, AAC, AMR, JPG, PNG, GIF)●GSM phone (depending on hardware)●Bluetooth Bluetooth, EDGE, 3G, and WiFi (hardware dependent)●Camera, GPS, compass, and accelerometer (hardware dependent)●Rich development environment including a device emulator, debugger,memory and performance analysis charts, and the Eclipse integrateddevelopment environment plug-insApplicationsA core Android application package together with the release of the application package, including email client, SMS short messaging program, calendar, maps, browser, contact management procedures. A ll applications are written using JA V A.Android Application Framework Developers have full access to core applications used by the API framework. The application framework designed to simplify the reuse of software components; any application can publish its functional blocks and any other applications can use the function block its release (but must follow the framework of security restrictions). Reuse mechanism allows the application form can be user replaced.All of the following applications by the composition of a range of services and systems, including:●an expanded view (V iews) can be used to build applications, including a list of(lists), grid (grids), text boxes (text boxes), buttons (buttons), and even an embeddable web browser.●Content Manager (Content Providers) allows applications to access data fromanother application program (such as the contact database), or to share their own data.● A resource manager (Resource Manager) to provide access to non-coderesources, such as local strings, graphics, and hierarchical file (layout files).● A notification manager (Notif ication Manager) allows applications to customersin the status bar display notification information.●An activity class Manager (Activity Manager) to manage the application lifecycle and provides common navigation rollback feature.Ordering the systemOrdering the system information using automated software tools to achieve la carte, side dishes, stir fry vegetables to the transfer of all management processes; completion point, the computer management menu, point the menu and the kitchen, front-end checkout synchronization print; achieved without the menu paper-based operation; backstage manager of inquiry; warehouse inventory management and so on.In addition, ordering the system can also effectively manage customer data, archiving and future reference, put an end to the restaurant "leakage List", "run list" phenomenon; help restaurants using computer data processing capability and powerful ability to process optimization to achieve automated management, streamline workflow restaurant, reduce waste and man-made phenomenon of management oversight, re-optimal allocation of corporate resources, the operating costs to a minimum.Powerful addition to ordering the system to support the general application of stand-alone and LAN in addition to support head office / branch of multi-level framework used for remote network using the POS system to achieve front store sales cashier, sales of small-ticket instantly print sales day-end, reporting sales data and receive information of new featuresdishes.There are three currently ordering the system to achieve mode:First, the touch screen a la carte model: It uses the currently most popular touch-computer ordering process to achieve that members can to order the software screen prompts, simply click on the screen with your fingers can complete the entire ordering process and convenient This model applies to the practice of rich dishes and large restaurants, restaurants, and restaurant, etc..Second,the wireless PDA ordering mode: it uses a wireless WiFi technology, a la carte interface by PDA display, use touch pen to complete the ordering process, virtuallyanywhere, anytime to order real-time response, this model is more suitable for dishes and practices simple restaurant, features a restaurant and special mood of senior restaurants.Third, the wireless ordering Po mode: it uses the ISM band, can be a floor or other obstruction in the case of seamless coverage up to 10 meters away, while the signal remained stable, which is the ratio of the wireless PDA ordering model's greatest strength, this model applies to simple dishes and practices and other requirements with fewer fast food restaurants, pot shops.。

无线通信英文版教学设计 (2)

无线通信英文版教学设计 (2)

无线通信英文版教学设计1. IntroductionWireless communication is the exchange of information between two or more devices without the use of cables or wires. Wireless communication is an essential part of modern life and has transformed the way we communicate. This course is designed to provide students with a solid foundation in wireless communication principles, practices, and technologies.2. Course ObjectivesThe objectives of this course are: - To introduce the fundamental principles of wireless communication. - To expln the different types of wireless communication systems and their applications. - To teach the basic concepts of radio frequency (RF) technology and wireless network architecture. - To discuss the various communication standards that govern wireless communication. - To provide hands-on experience in building wireless communication systems.3. Course OutlineThe course will cover the following topics:Week 1: Introduction to Wireless Communication•Overview of wireless communication•Types of wireless communication systems•Applications of wireless communicationWeek 2: Basic Concepts of Radio Frequency (RF) Technology•RF waves and signals•Modulation techniques•Demodulation techniquesWeek 3: Wireless Network Architecture•Wireless network topologies•Wireless access points and routers•Wireless network securityWeek 4: Wireless Communication Standards•IEEE 802.11 (Wi-Fi)•Bluetooth•Cellular networks (GSM, CDMA)Week 5: Building Wireless Communication Systems•Basic hardware components of a wireless communication system•Installing and configuring a wireless access point•Troubleshooting wireless network issues4. Teaching MethodologyThis course will be delivered through a combination of lectures, readings, assignments, and hands-on projects. Lectures will provide an introduction to the topic and cover the theoretical aspects of wireless communication. Readings will supplement the lectures and provide additional information on the course topics. Assignments will be given to evaluate the student’s understandin g of the course material. Hands-on projects will provide practical experience in building wireless communication systems.5. Assessment and GradingThe grade for this course will be based on the following components: Component WeightageAssignments 40%Hands-on Projects 30%Final Exam 30%6. References•Andreas F. Molisch,。

  1. 1、下载文档前请自行甄别文档内容的完整性,平台不提供额外的编辑、内容补充、找答案等附加服务。
  2. 2、"仅部分预览"的文档,不可在线预览部分如存在完整性等问题,可反馈申请退款(可完整预览的文档不适用该条件!)。
  3. 3、如文档侵犯您的权益,请联系客服反馈,我们会尽快为您处理(人工客服工作时间:9:00-18:30)。

Wireless communicationModern computer technology, industrial revolution, the world economy from the capital into the economy to knowledge economy. Field in the electronic world, from the 20th century into the era of radio to computer technology in the 21st century as the center of the intelligent modern era of electronic systems. The basic core of modern electronic systems are embedded computer systems (referred to as embedded systems), while the microcontroller is the most typical and most extensive and most popular embedded systems.First, radio has created generations of excellence in the worldFifties and sixties in the 20th century, the most representative of the advanced electronic technology is wireless technology, including radio broadcasting, radio, wireless communications (telegraph), Amateur Radio, radio positioning, navigation and other telemetry, remote control, remote technology. Early that these electronic technology led many young people into the wonderful digital world, radio show was a wonderful life, the prospects for science and technology. Electronics began to form a new discipline. Radio electronics, wireless communications began e-world journey. Radio technology not only as a representative of advanced science and technology at that time, but also from popular to professional fields of science, attracting the young people and enable them to find a lot of fun. Ore from the bedside to the superheterodyne radio radio; report issued from the radio amateur radio stations; from the telephone, electric bell to the radio control model. Became popular youth radio technology, science and technology education is the most popular and most extensive content. So far, many of the older generation of engineers, experts, Professor of the year are radio enthusiasts. Fun radio technology, radio technology, comprehensive training, from basic principles of electronics, electronic components to the radio-based remote control, telemetry, remote electronic systems, has trained several generations of technological excellence.Second, from the popularity of the radio era to era of electronic technologyThe early radio technology to promote the development of electronic technology, most notably electronic vacuum tube technology to semiconductor electronictechnology. Semiconductor technology to realize the active device miniaturization and low cost, so more popular with radio technology and innovation, and to greatly broaden the number of non-radio-control areas. The development of semiconductor technology lead to the production of integrated circuit, forming the modern electronic technology leap from discrete electronics into the era of era of integrated circuits. Electronic design engineers no longer use the discrete electronic components designed circuit modules, and direct selection of integrated circuit components constitute a single system. They freed the design of the circuit unit dedicated to system design, greatly liberating the productive forces of science and technology, promote the wider spread of electronic systems. Semiconductor integrated circuits in the basic digital logic circuits first breakthrough. A large number of digitallogic circuits, such as gates, counters, timers, shift registers, and analog switches, comparators, etc., for the electronic digital control provides excellent conditions for the traditional mechanical control to electronic control. Power electronic devices and sensor technology to make the original to the radio as the center of electronic technology turned to mechanical engineering in the field of digital control systems, testing in the field of information collection, movement of electrical mechanical servo drive control object. Semiconductor and integrated circuit technology will bring us a universal age of electronic technology, wireless technology as the field of electronic technology a part of. 70 years into the 20th century, large scale integrated circuit appeared to promote the conventional electronic circuit unit-specific electronic systems development. Many electronic systems unit into a dedicated integrated devices such as radios, electronic clocks, calculators, electronic engineers in these areas from the circuit, the system designed to debug into the device selection, peripheral device adapter work. Electronic technology, and electronic products enriched, electronic engineers to reduce the difficulty, but at the same time, radio technology, electronic technology has weakened the charm. The development of semiconductor integrated circuits classical electronic systems are maturing, remain in the large scale integrated circuit other thanthe shrinking of electronic technology, electronic technology is not the old days of radio fun times and comprehensive engineering training.Third, from the classic era of electronic technology to modern electronic technology of the times80 years into the 20th century, the century of economic change is the most important revolution in the computer. The computer revolution in the most important sign is the birth of the computer embedded applications. Modern computer numerical requirements should be born. A long period of time, is to develop the massive computer numerical duty. But the computer shows the logic operation, processing, control, attracting experts in the field of electronic control, they want development to meet the control object requirements of embedded applications, computer systems. If you meet the massive data-processing computer system known as general-purpose computer system, then the system can be the embedded object (such as ships, aircraft, motorcycles, etc.) in a computer system called the embedded computer. Clearly, both the direction of technology development are different. The former requires massive data storage, handling, processing and analysis of high-speed data transmission; while the latter requires reliable operation in the target environment, the external physical parameters on high-speed acquisition, analysis and processing logic and the rapid control of external objects. It will add an early general-purpose computer data acquisition unit, the output driver circuit reluctance to form a heat treatment furnace temperature control system. This general-purpose computer system is not possible for most of the electronic system used, and to make general-purpose computer system meets the requirements of embedded applications, will inevitably affect the development of high-speed numeric processing. In order to solve the contradiction between the development of computer technology, in the 20th century 70s, semiconductor experts another way, in full accordance with the electronic systemembedded computer application requirements, a micro-computer's basic system on a chip, the formation of the early SCM (Single Chip Microcomputer). After the advent of single chip in the computer industry began to appear in the general-purpose computer systems and embedded systems the two branches. Since then, both the embedded system, or general-purpose computer systems have been developed rapidly.Although the early general-purpose computer converted the embedded computer systems, and real embedded system began in the emergence of SCM. Because the microcontroller is designed specifically for embedded applications, the MCU can only achieve embedded applications. MCU embedded applications that best meet environmental requirements, for example, chip-level physical space, large-scale integrated circuits low-cost, good peripheral interface bus and outstanding control of instruction. A computer system microcontroller core, embedded electronic systems, intelligent electronic systems for the foundation. Therefore, the current single chip electronic system in widespread use of electronic systems to enable rapid transition to the classical modern intelligent electronic systems.Forth, single chip to create the modern era of electronic systems.A microcontroller and embedded systems Embedded computer systems from embedded applications, embedded systems for early general-purpose computer adapted to the object system embedded in a variety of electronic systems, such as the ship's autopilot, engine monitoring systems. Embedded system is primarily a computer system, followed by it being embedded into the object system, objects in the object system to achieve required data collection, processing, status display, the output control functions, as embedded in the object system, embedded system computer does not have an independent form and function of the computer. SCM is entirely in accordance with the requirements of embedded system design, so SCM is the most typical embedded systems. SCM is the early application of technical requirements in accordance with the design of embedded computer chip integration, hence the name single chip. Subsequently, the MCU embedded applications to meet the growing demands of its control functions and peripheral interface functions, in particular, highlight the control function, so has international name the single chip microcontroller (MCU, Microcontroller Unit).2 MCU modern electronic systems consisting of electronic systems will become mainstreamMCU is a device-level computer systems, it can be embedded into any object system to achieve intelligent control. Small to micro-machinery, such as watches,hearing aids.Low-cost integrated device-level, low-to a few dollars, ten dollars, enough to spread to many civilian SCM appliances, electronic toys to go. SCM constitutes a modern electronic systems has in-depth to the households, are changing our lives, such as home audio, televisions, washing machines, microwave ovens, telephones, security systems, and air conditioners. SCM innovation the original electronic systems, such as microwave ovens use SCM, it can easily set the clock, the program memory, power control; air conditioner after use of SCM is not only convenient for remote parameter setting, running automatically transform, frequency control can be achieved.At present, many household appliances such as VCD, DVD only single chip to achieve its function may occur before. 3 Embedded Systems led the entire electronics industry Current electronic components industry, in addition to microprocessors, embedded system devices, the most modern electronic systems around the supporting components industries, such as keys used to meet the human-computer interaction, LED / LCD display drivers, LED / LCD display units, voice integrated device, etc., to meet the requirements of data acquisition channel digital sensor, ADC, data acquisition module, signal conditioning modules to meet the servo drive control in the DAC, solid state relays, stepper motor controller, frequency control unit, etc., to meet the communication requirements various bus driver, level converters. Electronic components in the embedded systems world, driven by embedded applications along fully meet requirements of modern electronic systems development. This makes the original classic world of increasingly small electronic systems. Practitioners in the various electronic systems to modern electronic systems as early as possible to stay.Fifth, SCM will create a new generation of electronic elite.If the 50's, radio has created several generations of the world elite, then today's SCM will create a new generation of e-world elite. A single chip with you to the intelligent electronics If we as a dead classic electronic system electronic system, then the intelligent modern electronic systems is a "life" of the electronic system. Application System of hardware, electronic systems, "body", microcontroller applications, the applicationgives it "life." For example, in the design of intelligent machines monitor display, it can boot the system self-test results show, not to enter the work shows a variety of stand-by state, equipment run-time display running processes, work can be displayed after the end of the current results, self results, raw data, reports and other various processing. Unattended, it can run automatically given a variety of functions. Intelligent electronic systems for the endless realm, often without additional hardware resources can achieve all kinds of renovated function. It is also present in many household appliances feature a large number of additional factors. 2 single chip computer with you to the industrial area The 21st century is the century of humanity into the computer age, many people are not used in the manufacture of computer is the computer. People using the computer, only the people engaged in embedded system applications really into the internal computer system hardware and software systems, can we truly understand the nature of the computer's intelligence and grasp the knowledge of intelligent design. MCU applications starting from the learning technology applications in today's computer software training, hardware and technical personnel of one of the best roads. 3 SCM bring you into the most attractive in the digital world Charming single chip to enable you to experience the true meaning of the computer, you can design intelligent microcontroller hands-on toys, different applications can be designed to achieve different functions. Both software design and hardware making there, both mental and physical, but also hands. Primary level can develop intelligent toys, with macro programming. Intermediate levels can develop some intelligent controller, such as computer mouse, smart cars, all kinds of remote control model. High levels can be developed robots, such as robot soccer, the development of industrial control units, network communications, and high-levellanguage with assembly language or design application. Microcontroller and embedded systems around the formation of the future of the electronics industry, will provide a vast world of electronic fans, an even broader than the current wireless world, richer, more durable, more attractive in the digital world. Plunge into the microcontroller in the world to, will benefit your life.MCU AttacksCurrently, there are four single chip attack technique, namely: (1) software attack The technology is commonly used processor communication interface and use protocol, encryption algorithm or the algorithm of security vulnerabilities to attack. The success of software attack is a typical example of the early ATMEL AT89C MCU attacks. Attacker single chip erase operation of the timing design flaw, erase the encryption used by ourselves locked in place, the next stop on-chip program memory data erase operation, thus bringing into too close a single chip SCM not encrypted, and then use the programmer to read out chip program. (2) electronic detection of attacks The technology is usually a high time resolution to monitor the processor during normal operation of all power and interface simulation features, and by monitoring the electromagnetic radiation characteristics of it to attack. Because SCM is an active electronic device, when it executes a different command, the corresponding changes in the power consumption accordingly. This through the use of special electronic measuring instruments and mathematical statistical analysis and detection of these changes, you can access key information specific microcontroller.(3) fault generation technology Abnormal working conditions of the technology used to make the processor errors, and provide additional access to attack. Produce the most widely used means of attack, including the fault of the impact and the clock voltage shock. Low voltage and high voltage protection circuit attack can be used to prohibit the work of processor execution errors or enforcement action. Clock transition may reset the transient protection circuit will not damage the protected information. Power and clock transients transition effects in certain single-processor instruction decoding and execution. (4) probe This technology is directly exposed to chip connection, and then observe, manipulate, interfere with single chip to achieve the attack purpose. For convenience, these four people will attack techniques are divided into two categories is theintrusion type attack (physical attack), such attack requires destruction of package, then use semiconductor test equipment, microscopes and micro-positioning device, in a special laboratory spend hours or even weeks to complete. All of the micro-probe techniques are invasive type attack. The other three methods are non-invasive type attack, attack the MCU will not be physical damage. In some cases, non-invasive-type attacks are particularly dangerous, but because of non-invasive type attacks can usually be made and the necessary equipment to upgrade, so it is cheap. Most non-invasive type attack requires the attacker have a good knowledge of processors and software knowledge. In contrast, the invasive type of probe do not need too much of the initial attack of knowledge, and usually a set of similar technology available to deal with a wide range of productsMCU general process of invasion-type attackInvasive type of attack is thrown off its first chip package. There are two ways to achieve this goal: the first one is completely dissolved out chip package, exposed metal connections. The second is only removed to the top of the plastic package silicon core. The first method is the need to bind to the test fixture on the chip, using bind Taiwan to operate. The second method requires the attacker in addition to a certain degree of knowledge and necessary skills, but also the wisdom and patience, but operate relatively easy. Above the plastic chips can be opened with a knife, epoxy around the chip can be eroded by concentrated nitric acid. Hot concentrated nitric acid will dissolve out without affecting the chip, chip packaging and connection. This process usually very dry conditions, because the presence of water may erode the aluminum wire connections have been exposed. Then, in ultrasonic cleaning of the pool first chip with acetone to remove residual nitric acid, then washed with water to remove salt and dried. No ultrasound pool, are generally skip this step. This case, the chip surface, a bit dirty, but do not affect the operation of UV effects on the chip. The final step is to find the location of the protection fuse and fuse protection under exposure to UV light. General use at least a 100 times magnification microscope, from the programming voltage input pin of the connection tracking in, to find protection fuse. If there is no microscope, theuse of different parts of the chip is exposed to ultraviolet light and observe the results under the simple search mode. Operation applied opaque paper cover to protect the program memory chips are not erased by ultraviolet light. Will protect the fuse exposed under UV light 5 to 10 minutes to destroy the protection bit of the protective effect, use a simple programmer can directly read the contents of program memory. The use of the protective layer to protect the MCU EEPROM cell, using ultraviolet light reset protection circuit is not feasible. For this type of MCU, the general use of micro-probe technology to read the memory contents. In the chip package is opened, the chip placed under the microscope can easily find from the memory circuit connected to other parts of the data bus. For some reason, the chip lock-bit programming mode is not locked in the memory of the visit. Advantage of this flaw on the data lines to probe the above data can be read all you want. In programming mode, restart the process of reading and connect probe to the other data can be read online program and data memory, all of the information. There is also a possible means of attack is the use of microscopy and laser cutting machines and other equipment to find the fuse protection to this part of the circuit tracing and linking all the signal lines. Because of the design defects, so long as cut off from other circuit protection fuse to a one signal line, you can ban the entire protection. For some reason, this thread is very far from the other line, so the use of laser cutting machine can cut the wire without affecting the adjacent line. In this way, using a simple programmer can directly read the contents of program memory. Although the most common single chip microcontroller has fuse blown inside the code protection features, but because of general low-end MCU is not positioning the production of safe products, so they often do not provide targeted preventive measures and the low level of security. MCU applications with a broad, large sales volume, commission processing and transfer of technology between firms frequently spilled a lot oftechnical data, making use of loopholes in the design of such chips and test interface manufacturer, and by modifying the invasive type fuse protection bits, etc. means of attack or invasion-type attack to read MCU's internal procedureshave become easier.About common single chipSTC microcontroller STC's mainly based on the 8051 microcontroller core is a new generation of enhanced MCU, the instruction code is fully compatible with the traditional 8051, 8 to 12 times faster, with ADC, 4 Road, PWM, dual serial ports, a global unique ID, encryption of good, strong anti-interference. PIC Microcontroller: MICROCHIP's products is its prominent feature is a small, low power consumption, reduced instruction set, interference, reliability, strong analog interface, the code of confidentiality is good, most of the chip has its compatibleFLASH program memory chips. EMC SCM: Elan's products in Taiwan, with much of the PIC 8-bit microcontroller compatible, and compatible products, resources, compared to the PIC's more, cheap, there are many series of options, but less interference. ATMEL microcontroller (MCU 51): ATMEl company's 8-bit microcontroller with AT89, AT90 two series, AT89 series is the 8-bit Flash microcontroller 8051 is compatible with the static clock mode; AT90 RISC MCU is to enhance the structure, all static methods of work, containing the line can be Flash MCU programming, also known A VR microcontroller. PHLIPIS 51PLC Microcontroller (MCU 51): PHILIPS company's MCU is based on the 80C51 microcontroller core, embedded power-down detection, simulation and on-chip RC oscillator and other functions, which makes 51LPC in highly integrated, low cost, low power design to meet various applications performance requirements. HOLTEK SCM: Sheng Yang, Taiwan Semiconductor's single chip, cheap more categories, but less interference for consumer products. TI company microcontroller (MCU 51):Texas Instruments MSP430 provides the TMS370 and two series of general-purpose microcontroller. TMS370 MCU is the 8-bit CMOS MCU with a variety of storage mode, a variety of external interface mode, suitable for real-time control of complex situations; MSP430 MCU is a low power, high functionality integrated 16-bit low-power microcontroller, especially for applications that require low power consumption occasions Taiwan Sonix's single, mostly 8-bit machines, some with PIC 8-bit microcontroller compatible, cheap, the system clock frequency may be more options there PMW ADC internal noise filtering within the vibration. Shortcomings RAM space is too small, better anti-interference.无线通信从无线电世界到单片机世界现代计算机技术的产业革命,将世界经济从资本经济带入到知识经济时代。

相关文档
最新文档