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systems-High

  • VxWorks6.x中的ML403嵌入式开发平台

    The use of the Wind River VxWorks Real-Time Operating System (RTOS) on Virtex™-4embedded PowerPC™ processors continues to be a popular choice for high performanceFPGA designs. The introduction of the Wind River Workbench design environment has enableda new and easier way for designers to control the configuration of the VxWorks kernel. Thisguide shows the steps required to build and configure a ML403 Embedded DevelopmentPlatform to boot and run the VxWorks RTOS. A VxWorks bootloader is created, programmedinto Flash, and used to boot the design. The concepts presented here can be scaled to anyPowerPC enabled development platform.

    标签: VxWorks 403 ML 嵌入式

    上传时间: 2013-10-26

    上传用户:agent

  • NCV7356单线CANBUS收发器数据手册

    The NCV7356 is a physical layer device for a single wire data linkcapable of operating with various Carrier Sense Multiple Accesswith Collision Resolution (CSMA/CR) protocols such as the BoschController Area Network (CAN) version 2.0. This serial data linknetwork is intended for use in applications where high data rate is notrequired and a lower data rate can achieve cost reductions in both thephysical media components and in the microprocessor and/ordedicated logic devices which use the network.The network shall be able to operate in either the normal data ratemode or a high-speed data download mode for assembly line andservice data transfer operations. The high-speed mode is onlyintended to be operational when the bus is attached to an off-boardservice node. This node shall provide temporary bus electrical loadswhich facilitate higher speed operation. Such temporary loads shouldbe removed when not performing download operations.The bit rate for normal communications is typically 33 kbit/s, forhigh-speed transmissions like described above a typical bit rate of83 kbit/s is recommended. The NCV7356 features undervoltagelockout, timeout for faulty blocked input signals, output blankingtime in case of bus ringing and a very low sleep mode current.

    标签: CANBUS 7356 NCV 单线

    上传时间: 2013-10-24

    上传用户:s蓝莓汁

  • 移动无线终端导航AFE和数据转换器

    Abstract: High-speed and low-speed data converters serve critical functions in modern broadband mobile radios. This application note outlines how todetermine high-speed data converter performance requirements in baseband sampling radio architectures. Also, system partition strategies andadvantages are outlined when considering a high-speed analog front-end (AFE) solution.

    标签: AFE 移动 无线终端 导航

    上传时间: 2013-11-02

    上传用户:jjj0202

  • 线性低压差 (LDO) 稳压器解决方案

    We offer a broad line of high performance low dropout (LDO) linear regulators with fasttransient response, excellent line and load regulation, and very wide input voltage rangefrom 0.9V to 100V. Output currents range from 20mA to 10A, with positive, negative andmultiple output versions available. Many devices offer output voltage operation <0.8V andsome feature operation as low as 0V, even with a single supply. Most are stable with ceramicoutput capacitors. LDO regulators can be applied in virtually any application.

    标签: LDO 线性 低压差 稳压器

    上传时间: 2013-11-15

    上传用户:努力努力再努力

  • 无线电设计入门资料

    Abstract: The process of designing a radio system can be complex and often involves many project tradeoffs. Witha little insight, balancing these various characteristics can make the job of designing a radio system easier. Thistutorial explores these tradeoffs and provides details to consider for various radio applications. With a focus on theindustrial, scientific, medical (ISM) bands, the subjects of frequency selection, one-way versus two-way systems,modulation techniques, cost, antenna options, power-supply influences, effects on range, and protocol selectionare explored.

    标签: 无线

    上传时间: 2013-12-13

    上传用户:eastgan

  • 无线和RF解决方案

    Linear Technology offers some of the highest performance RF and signal chain solutions for wireless and cellularinfrastructure. These products support worldwide standards including, LTE, WiMAX, GSM,W-CDMA, TD-SCDMA,CDMA, and CDMA2000. Other wireless systems include broadband microwave data links, secure communications,satellite receivers, broadband wireless access, wireless broadcast systems, RFID readers and cable infrastructure

    标签: 无线 方案

    上传时间: 2013-11-04

    上传用户:kiklkook

  • 无线电干扰 Radio Susceptibility

      Abstract: Engineers often wish that radio susceptibility (RS) or radio immunity could be cured with an antibiotic, a vaccine, or someform of cure-all. Unfortunately, solving the RS problem is not that easy. Indeed, the laws of physics apply. In this article we discusssources of RS. We also offer tips and hints to protect systems, power supplies, printed circuit boards (PCBs), and electroniccomponents from radio frequency interference.

    标签: Susceptibility Radio 无线电干扰

    上传时间: 2014-12-30

    上传用户:旗鱼旗鱼

  • 智能天线技术在基站中的应用

    为了能够满足基站易于选址、优质快速的建站要求和易维护、低成本、高可靠的运行要求,本文对以方舱来实现一体化结构基站做出一番探讨。从系统设计的观点阐述了移动通信高性能基站天线设计的几个关键问题,介绍了智能天线技术在基站中的应用,并且用HFSS软件仿真了一种新型的对称阵子天线,该天线驻波比小于2的带宽可以达到60%,具有良好的宽频带特性。 Abstract:  In order to meet the station construction requirement of easy site selection and fast base station, and meet the operational requirement of easy maintenance, low cost and high reliability, this paper discussed the unified architecture base station using shelter. Several key problems of high performance mobile communication base station antenna were illustrated from the view of system design, the application of smart antenna in base station was also introduced. And a novel dipole antenna was simulated by using HFSS, the VSWR of the antenna is less than 2, and the bandwidth was reach to 60%. So it has good broadband properties.

    标签: 智能天线 基站 中的应用

    上传时间: 2013-11-20

    上传用户:linlin

  • UHF读写器设计中的FM0解码技术

       针对UHF读写器设计中,在符合EPC Gen2标准的情况下,对标签返回的高速数据进行正确解码以达到正确读取标签的要求,提出了一种新的在ARM平台下采用边沿捕获统计定时器数判断数据的方法,并对FM0编码进行解码。与传统的使用定时器定时采样高低电平的FM0解码方法相比,该解码方法可以减少定时器定时误差累积的影响;可以将捕获定时器数中断与数据判断解码相对分隔开,使得中断对解码影响很小,实现捕获与解码的同步。通过实验表明,这种方法提高了解码的效率,在160 Kb/s的接收速度下,读取一张标签的时间约为30次/s。 Abstract:  Aiming at the requirement of receiving correctly decoded data from the tag under high-speed communication which complied with EPC Gen2 standard in the design of UHF interrogator, the article introduced a new technology for FM0 decoding which counted the timer counter to judge data by using the edge interval of signal capture based on the ARM7 platform. Compared with the traditional FM0 decoding method which used the timer timed to sample the high and low level, the method could reduce the accumulation of timing error and could relatively separate capture timer interrupt and the data judgment for decoding, so that the disruption effect on the decoding was small and realizd synchronization of capture and decoding. Testing result shows that the method improves the efficiency of decoding, at 160 Kb/s receiving speed, the time of the interrogator to read a tag is about 30 times/s.

    标签: UHF FM0 读写器 解码技术

    上传时间: 2013-11-10

    上传用户:liufei

  • 快速跳频通信系统同步技术研究

    同步技术是跳频通信系统的关键技术之一,尤其是在快速跳频通信系统中,常规跳频通信通过同步字头携带相关码的方法来实现同步,但对于快跳频来说,由于是一跳或者多跳传输一个调制符号,难以携带相关码。对此引入双跳频图案方法,提出了一种适用于快速跳频通信系统的同步方案。采用短码携带同步信息,克服了快速跳频难以携带相关码的困难。分析了同步性能,仿真结果表明该方案同步时间短、虚警概率低、捕获概率高,同步性能可靠。 Abstract:  Synchronization is one of the key techniques to frequency-hopping communication system, especially in the fast frequency hopping communication system. In conventional frequency hopping communication systems, synchronization can be achieved by synchronization-head which can be used to carry the synchronization information, but for the fast frequency hopping, Because modulation symbol is transmitted by per hop or multi-hop, it is difficult to carry the correlation code. For the limitation of fast frequency hopping in carrying correlation code, a fast frequency-hopping synchronization scheme with two hopping patterns is proposed. The synchronization information is carried by short code, which overcomes the difficulty of correlation code transmission in fast frequency-hopping. The performance of the scheme is analyzed, and simulation results show that the scheme has the advantages of shorter synchronization time, lower probability of false alarm, higher probability of capture and more reliable of synchronization.

    标签: 快速跳频 同步技术 通信系统

    上传时间: 2013-11-23

    上传用户:mpquest