同步技術是跳頻通信系統的關鍵技術之一，尤其是在快速跳頻通信系統中，常規跳頻通信通過同步字頭攜帶相關碼的方法來實現同步，但對于快跳頻來說，由于是一跳或者多跳傳輸一個調制符號，難以攜帶相關碼。對此引入雙跳頻圖案方法，提出了一種適用于快速跳頻通信系統的同步方案。采用短碼攜帶同步信息，克服了快速跳頻難以攜帶相關碼的困難。分析了同步性能，仿真結果表明該方案同步時間短、虛警概率低、捕獲概率高，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.
提出了一種以ARM微處理器為控制核心的遠程無線視頻監控終端的設計方案，其監控終端的硬件設計包括視頻采集處理、中央管理控制、無線傳輸3個模塊。并給出了監控終端的軟件開發平臺和開發模式的系統啟動代碼、嵌入式Linux系統移植以及驅動程序和應用程序。測試結果表明，該監控終端設計方案合理、有效，基本滿足監控需求。
Abstract:
A remote wireless video monitoring terminal design， which uses ARM microprocessor as its core control， is proposed in this paper.The hardware design of monitoring terminal system is composed of the video acquisition and processing module， the central management and control module， wireless TRAnSMISSION module.Meanwhile the monitoring terminal-s software development platform and development patterns are designed. Also the design of the system-s start codes， embedded Linux system-s transplantation process， driver and the corresponding applications are given. The results showed that the monitoring terminal design is reasonable， effective， basically meet monitoring requirements.
針對嵌入式機器視覺系統向獨立化、智能化發展的要求，介紹了一種嵌入式視覺系統--智能相機。基于對智能相機體系結構、組成模塊和圖像采集、傳輸和處理技術的分析，對國內外的幾款智能相機進行比較。綜合技術發展現狀，提出基于FPGA+DSP模式的硬件平臺，并提出智能相機的發展方向。分析結果表明，該系統設計可以實現脫離PC運行，完成圖像獲取與分析，并作出相應輸出。
Abstract:
This paper introduced an embedded vision system-intelligent camera ，which was for embedded machine vision systems to an independent and intelligent development requirements. Intelligent camera architecture， component modules and image acquisition， TRAnSMISSION and processing technology were analyzed. After comparing integrated technology development of several intelligent cameras at home and abroad， the paper proposed the hardware platform based on FPGA+DSP models and made clear direction of development of intelligent cameras. On the analysis of the design， the results indicate that the system can run from the PC independently to complete the image acquisition and analysis and give a corresponding output.
Calculation of the Differential Impedance of Tracks on FR4 substrates
There is a discrepancy between calculated and measured values of impedance for differential TRAnSMISSION lineson FR4. This is especially noticeable in the case of surface microstrip configurations. The anomaly is shown tobe due to the nature of the substrate material. This needs to be considered as a layered structure of epoxy resinand glass fibre. Calculations, using Boundary Element field methods, show that the distribution of the electricfield within this layered structure determines the apparent dielectric constant and therefore affects theimpedance. Thus FR4 cannot be considered to be uniform dielectric when calculating differential impedance.
Accurate measurement of the third order intercept pointfor low distortion IC products such as the LT5514 requirescertain precautions to be observed in the test setup andtesting procedure. The LT5514 linearity performance ishigh enough to push the test equipment and test set-up totheir limits. A method for accurate measurement of thirdorder intermodulation products, IM3, with standard testequipment is outlined below.It is also important to correctly interpret the LT5514specification with respect to ROUT, and the impact ofdemo-board TRAnSMISSION-line termination loss whenevaluating the linearity performance, as explained in theLT5514 Datasheet and in Note 1 of this document.
ITU-T Recommendation T.30(2005 09)
SERIES T: TERMINALS FOR TELEMATIC SERVICES
Procedures for document facsimile TRAnSMISSION in the general switched telephone network
The JICQ is the bureau area which JAVA writes according to "Customer s Machine/Server"(C/S) mode message solid hour correspond by letter tool system, the system adopted the SQL Server2000 of Microsoft company as a backstage database, the system passes a JDBC interview database. The system is divided into the server procedure and customer s procedure two parts, server and customer adoption "TRAnSMISSION Control Protocol"(TCP), connect a word (Socket) conjunction through a set, the adoption "User Datagram Protocol "(UDP) of the customer s, pass a data report a set to connect a word (DatagramSocket) establishment a conjunction. The system has customer registration, customer to register, increase good friend, delete good friend and send out and receive news etc. function.
