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.
上传时间： 2013-11-23
上传用户：mpquest
The information in this specification is subject to change without notice.Use of this specification for product design requires an executed license agreement from the CompactFlashAssociation.The CompactFlash Association shall not Be liable for technical or editorial errors or omissions contained herein; norfor incidental or consequential damages resulting from the furnishing, performance, or use of this material.All parts of the CompactFlash Specification are protected by copyright law and all rights are reserved. Thisdocumentation may not, in whole or in part, Be copied, photocopied, reproduced, translated, or reduced to anyelectronic medium or machine readable form without prior consent, in writing, from the CompactFlash Association.The CFA logo is a trademark of the CompactFlash Association.Product names mentioned herein are for identification purposes only and may Be trademarks and/or registeredtrademarks of their respective companies.© 1998-99, CompactFlash Association. All rights reserved.
标签： 技术资料
上传时间： 2013-10-08
上传用户：stewart·
Single-Ended and Differential S-Parameters Differential circuits have Been important incommunication systems for many years. In the past,differential communication circuits operated at lowfrequencies, where they could Be designed andanalyzed using lumped-element models andtechniques. With the frequency of operationincreasing Beyond 1GHz, and above 1Gbps fordigital communications, this lumped-elementapproach is no longer valid, Because the physicalsize of the circuit approaches the size of awavelength.Distributed models and analysis techniques are nowused instead of lumped-element techniques.Scattering parameters, or S-parameters, have Beendeveloped for this purpose [1]. These S-parametersare defined for single-ended networks. S-parameterscan Be used to descriBe differential networks, but astrict definition was not developed until Bockelmanand others addressed this issue [2]. Bockelman’swork also included a study on how to adapt single-ended S-parameters for use with differential circuits[2]. This adaptation, called “mixed-mode S-parameters,” addresses differential and common-mode operation, as well as the conversion Betweenthe two modes of operation.This application note will explain the use of single-ended and mixed-mode S-parameters, and the basicconcepts of microwave measurement calibration.
上传时间： 2014-03-25
上传用户：yyyyyyyyyy
The LTC®3207/LTC3207-1 is a 600mA LED/Camera driverwhich illuminates 12 Universal LEDs (ULEDs) and onecamera fl ash LED. The ULEDs are considered universalBecause they may Be individually turned on or off, setin general purpose output (GPO) mode, set to blink at aselected on-time and period, or gradate on and off at aselected gradation rate. This device also has an externalenable (ENU) pin that may Be used to blink, gradate, orturn on/off the LEDs without using the I2C bus. This may Beuseful if the microprocessor is in sleep or standby mode. Ifused properly, these features may save valuable memoryspace, programming time, and reduce the I2C traffi c.
上传时间： 2014-01-04
上传用户：LANCE
On the LPC13xx, programming, erasure and re-programming of the on-chip flash can Be performed using In-System Programming (ISP) via the UART serial port, and also, can Be performed using In-Application Programming (IAP) calls directed by the end-user code. For In-System Programming (ISP) via the UART serial port, the ISP command handler (resides in the bootloader) allows erasure of one or more sector (s) of the on-chip flash memory.
上传时间： 2013-12-13
上传用户：lmq0059
本软件是关于MAX338, MAX339的英文数据手册：MAX338, MAX339 8通道/双4通道、低泄漏、CMOS模拟多路复用器 The MAX338/MAX339 are monolithic, CMOS analog multiplexers (muxes). The 8-channel MAX338 is designed to connect one of eight inputs to a common output by control of a 3-bit binary address. The dual, 4-channel MAX339 is designed to connect one of four inputs to a common output by control of a 2-bit binary address. Both devices can Be used as either a mux or a demux. On-resistance is 400Ω max, and the devices conduct current equally well in both directions. These muxes feature extremely low off leakages (less than 20pA at +25°C), and extremely low on-channel leakages (less than 50pA at +25°C). The new design offers guaranteed low charge injection (1.5pC typ) and electrostatic discharge (ESD) protection greater than 2000V, per method 3015.7. These improved muxes are pin-compatible upgrades for the industry-standard DG508A and DG509A. For similar Maxim devices with lower leakage and charge injection but higher on-resistance, see the MAX328 and MAX329.
上传时间： 2013-11-12
上传用户：18711024007
The correct answer for each test bank question is highlighted in bold. Test bank questions are based on the end-of-chapter questions. If a student studies the end-of-chapter questions (which are linked to the italicized words in each chapter), then they will Be successful on the test bank questions.
上传时间： 2014-12-31
上传用户：旗鱼旗鱼
该电路集包括了从业界享有盛名的公司搜集到的大量最新电路，体现了丰富的设计思想。为便于读者理解和应用这些电路，本书几乎对每个电路都附有简要说明。$ C' I" t% P5 l3 V. l0 K, B 本书可供电子技术工作者、高等院校和中等专科学校师生、电子爱好者阅读和参考。( H& s, \, z6 ~% D: @
上传时间： 2013-10-19
上传用户：songnanhua
It would not Be an exaggeration to say that semiconductor devices have transformed humanlife. From computers to communications to internet and video games these devices and the technologies they have enabled have expanded human experience in a way that is unique in history. Semiconductor devices have exploited materials, physics and imaginative applications to spawn new lifestyles. Of course for the device engineer, in spite of the advances, the challenges of reaching higher frequency, lower power consumption, higher power generation etc.
上传时间： 2013-10-28
上传用户：songnanhua
This book evolved over the past ten years from a set of lecture notes developed while teaching the undergraduate Algorithms course at Berkeley and U.C. San Diego. Our way of teaching this course evolved tremendously over these years in a numBer of directions, partly to address our students' background (undeveloped formal skills outside of programming), and partly to reect the maturing of the eld in general, as we have come to see it. The notes increasingly crystallized into a narrative, and we progressively structured the course to emphasize the story line implicit in the progression of the material. As a result, the topics were carefully selected and clustered. No attempt was made to Be encyclopedic, and this freed us to include topics traditionally de-emphasized or omitted from most Algorithms books.
标签： Algorithms 算法
上传时间： 2013-11-11
上传用户：JamesB
