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15 December 2014 Volume 27 Issue 12
  
    Articles
    Improved PTS Algorithm for Reducing the PAPR of MIMO-OFDM System
    ZHANG Renye,BAI Enjian
    . 2014, 27(12):  1. 
    Abstract ( 687 )   PDF (662KB) ( 622 )  
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    Multiple input multiple output frequency division multiplexing technology is a wireless communication system combing OFDM and MIMO technology.The system also has the problem of high PAPR.This paper analyzes the model and the PAPR of MIMO-OFDM system,and proposes an iterative clipping PTS algorithm based on the suboptimal PTS algorithms.The algorithm first converts the MIMO-OFDM signal by iterative PTS algorithm for processing and then further reduces the system PAPR through the clipping process.Finally an improved method based on adaptive PTS algorithm is proposed.The simulation results show that the complexity of the system is decreased and the performance of PAPR is reduced,but the performance can be improved by adjusting the threshold.

    Hands-on Experience with a String Matching:CPU vs.GPU vs.FPGA
    LI Zhang,DU Huimin,WANG Yonggang
    . 2014, 27(12):  5. 
    Abstract ( 789 )   PDF (738KB) ( 724 )  
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    A comparison is made of the performance of string matching algorithm on CPU,GPU and FPGA platforms.GPU has more computing unit,greatly enhancing the efficiency for compute-intensive applications;while the programmable FPGA has great flexibility and a large number of logic unit,thus faster string matching.The analysis in the three implementations base on the snort shows that FPGA is the fastest (10 times faster than GPU) with CPU as the slowest;and that FPGA has the greatest resources consumption,followed by GPU,while CPU is the least and with simplest realization.

    Application of ZOOM-FFT in the Distance Measurement System for Train Docking
    LIU Wen,LIU Si,TANG Lijun,HE Huiyong,SUN Chunguang,WEN Yiqing,ZEN Pengfei
    . 2014, 27(12):  9. 
    Abstract ( 868 )   PDF (660KB) ( 564 )  
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    The ZOOM-FFT frequency subdivision technology was used in the distance measurement system for train docking,which adopts dual processors of DSP and FPGA to achieve FMCW radar sensor signal acquisition and processing.FPGA controls parallel A/D and transmits data with DSP by ZOOM-FFT algorithm to achieve real-time distance and outputted distance via RS 485.Theoretical analysis and laboratory experimental results indicate that the ZOOM-FFT frequency subdivision technology can improve the processing speed and the resolution of the system effectively,and that the system used the ZOOM-FFT can measure small distances.Under laboratory conditions,the absolute deviations of the distance measurement system are less than 0.2 m in 0.5~10 m and less than 0.5 m in 10~50 m.At the Changsha locomotive depot,the experimental results show that the measure results on SS8 model and HXD3C model and DF5 model satisfy the basic distance measure requirements,which the absolute deviations about 0.5 m in 10~-50 m and the maximum deviation is 0.64 m when the distance over 44 m.

    Comparison of Different Adaptive Filter Algorithms with Noise Location Given
    XU Xianwei,DOU Yanyan,TIAN Sucheng
    . 2014, 27(12):  13. 
    Abstract ( 683 )   PDF (1038KB) ( 548 )  
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    Most efficient methods for removing salt and pepper noise from the image detect noise at first,and then deal with the noise based on the detection result.The accuracy of those noise detection algorithms is high and the quality of the filter is closely related to the adaptive switch filter algorithm.A comparison of the performance of the three adaptive switching filter algorithms is made with the location of noise in image known.

    Frequency Estimation for Power System Based on Recursive Damped Least Square Algorithm
    LU Jin,WANG Xiaohua,GUO Shuyan,GAO Yinglong,WANG Yi
    . 2014, 27(12):  17. 
    Abstract ( 633 )   PDF (645KB) ( 663 )  
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    Least square method is a very widely used algorithm for system identification and parameter identification,which is suitable for off-line identification but has its limitations in identifying parameters online.A recursive damped least square parameter identification algorithm is proposed with limited data window,forgetting factor and the adaptive damping factor based on the traditional least square algorithm.Several detailed simulations have been done when power system contains the fundamental signal,harmonics and noise,and when the instantaneous frequency jumps occurs.The results verify the robustness,speed and accuracy of this method with superior effect than other methods.

    An Integrated Map-matching Algorithm Based on GPS
    CHEN Bin,WANG Ping,SHI Wenzao,XU Shiwu
    . 2014, 27(12):  20. 
    Abstract ( 753 )   PDF (691KB) ( 505 )  
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    Map-matching is a technique that corrects positioning errors in navigation system by means of software.The paper presents an integrated map-matching algorithm for decreasing the false matching rate and increasing the effectiveness of map-matching.A higher matching speed and lower matching error rate is achieved through a comprehensive judging procedure which corrects different sections by different matching algorithms.The technique combines the vertical projection algorithm which has a high speed performance but high incorrect matching rate using the historical trajectory calculation algorithm which has a low speed performance but low incorrect matching rate.The actual matching results of the GPS trajectory data show that the presented technique has better matching effect in complex networks,especially in crossroads.The technique has higher efficiency and practical value.

    Multimedia Wireless Scenario Simulation Platform Based on Mobile Agent
    LU Lai,CHEN Sihui
    . 2014, 27(12):  24. 
    Abstract ( 536 )   PDF (765KB) ( 492 )  
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    In wireless multimedia wireless communication system,video source at the sending end is encoded by a coding method to form a video frame,encapsulated into IP packets in the network layer and the transport layer,and then sent through the wireless channel to the receiving end for package solution and recovery at the receiver to obtain the video frame to form the reconstructed video stream.In this process,transmission quality of the transmission characteristics of the wireless channel affects the video.A multimedia information transmission in wireless network platform is proposed based on the Agent platform with integrated NS2 simulation tools.The simulation results show that the restored video information at the receiving end may be distorted compared to video source due to the fact that the characteristics of wireless channel is not ideal.

    Straight Pipe Ultrasonic Guided Wave Defect Detection Based on Modal Symmetric Algorithm
    CHEN Lanwei,JIANG Yinfang,YAN Youqi,GUO Huajie,ZhANG Wei
    . 2014, 27(12):  27. 
    Abstract ( 696 )   PDF (848KB) ( 486 )  
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    A modal symmetric algorithm capable of pulling away asymmetric modal of echo signal is designed for detecting defects near straight pipe structure.The modal symmetric curve is used to evaluate pipe structure health.A pipe test system is built to collect the crack near weld.It is found that the amplitude of defect modal symmetric curve rise obviously with the percent of defect circumference symmetric.This method also realizes the straight pipe structure health detection using ultrasonic guided waves.

    Control and Simulation of Concentration in Coagulation Bath of the Precursor of Carbon Fiber in the Dry Wet Spinning
    BIAN Yunpeng,QI Jie
    . 2014, 27(12):  31. 
    Abstract ( 658 )   PDF (657KB) ( 685 )  
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    With wet spinning as example,the relationship between supply water quantity and solvent concentration in is deduced and calculated using the diffusion model in the fiber,with polyacrylonitrile and dimethyl sulfoxide solution as spinning solution and dimethyl sulfoxide solution as solidifying solution.MATLAB simulation is employed to solve the deduced mathematical model to realize the automatic control of supply water quantity and solvent concentration of coagulation bath.

    Powered Temperature Cycle Test System Based on VB and PLC
    GUO Wutao,QI Jinpeng
    . 2014, 27(12):  34. 
    Abstract ( 692 )   PDF (580KB) ( 616 )  
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    A powered temperature cycle test system which is designed based on VB and PLC,using OPC technology to connect between VB and PLC.This system realizes the output control of voltage source by using PLC to meet the testing curve,and displays the real-time voltage and temperature curve on the VB interface.

    Design and Implementation of Temperature and Humidity Acquisition System Based on ZigBee
    LI Shudan,ZHANG Congsong,QIN Zhangjian,GAO Xin,LUO Su,GOU Pan,JIANG Zhicheng
    . 2014, 27(12):  37. 
    Abstract ( 919 )   PDF (729KB) ( 565 )  
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    This paper designs a ZigBee wireless network to satisfy the actual requirements for monitoring temperature and humidity in agriculture and industries.Soc CC2530 connected to RFX2401C,an RF front-end power amplifier,is set as the wireless RF module to design the corresponding software and hardware functional units in a ZigBee network,for the realization of wireless temperature and humidity of SHT71 monitoring at a long distance and in real time.Hardware units consist of ZigBee coordinators and SHT71-sensor nodes,while the software unit is based on Z-Stack-2007 protocol stack to realize the control functions in the upper layers.The experiment proves that with the help of RFX2401,the ZigBee network can cover a larger area;in addition,the CC2530 can provide more pins to reuse.

    Realization of Partial Body Weight Support System
    XIONG Ming
    . 2014, 27(12):  41. 
    Abstract ( 712 )   PDF (526KB) ( 453 )  
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    The rehabilitation robot weight support system is introduced,with the linear actuator as main component of support system and the H bridge to drive linear actuator.The double closed-loop feedback control is used as the system controller,in which the current controller acts as the inner loop controller and velocity feedback controller as an outer loop controller,both using PID controller.PID parameters are tuned by genetic algorithm,and delay sampling strategy ensures the integrity of the current controller parameters.Actual uses show that the double closed-loop feedback control weight support system can meet the basic requirements of constant force output.

    Based on the DSP Mass Integration Implementation of Real-time Multimedia Data Analysis
    WU Guifen
    . 2014, 27(12):  44. 
    Abstract ( 427 )   PDF (790KB) ( 568 )  
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    In view of the traditional system real-time performance,analysis of the problem of the great error.Designed the massive amounts of real-time multimedia data analysis system based on DSP,with high-speed DSP as the core architecture,to more modeling of the experimenter,and based on the analysis of the model correlation characteristics,complete the data extraction and fusion processing.The experimental results show that the system of real-time and accuracy are greatly improved.

    Design and Implementation of Automatic Monitoring System of City Road Waterlogging
    XU Min,XIAO Yingping
    . 2014, 27(12):  48. 
    Abstract ( 625 )   PDF (775KB) ( 494 )  
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    Traditional road waterlogging monitoring systems have a small monitoring area,poor reliability and extensibility.A monitoring data acquisition device is designed with water level and rainfall sensors,which is capable of hydrological parameters collection,transmission,analysis and storage with the help of intelligent remote terminal units based on the wireless communication network with kingview software.The results of running test show that the device realizes accurate data acquisition and steady transmission.

    Image Acquisition and Processing in the Camera Searching Track Car
    YANG Tairen,LIU Haigang,XIANG Huazhen,ZHANG Jianwei,ZHOU Yuanqiang
    . 2014, 27(12):  52. 
    Abstract ( 640 )   PDF (1556KB) ( 621 )  
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    In order to make the Camera tracing car can run automatically and stably in different track,we design an image acquisition and processing system using an area array CCD camera as image sensor to collect the image data,using MC9S12XS128 as the main processor to process digital image,using LM1881 to separate video signals and using the high speed AD TLC5510 gathering and quantify analog video signal.In the image preprocessing,we use the improved median filtering algorithm for image filtering and use histogram calculated the dynamic threshold of two binary images,In addition,we use different interpolation algorithms in the black line extraction according to the different characteristics.Experiments show that,the algorithm has good robustness,reliability and real-time,and the car can run stably and fatly.

    Blurred Image Restoration Under Uniform Linear Motion
    SHENG Wenzheng,TANG Guohong
    . 2014, 27(12):  58. 
    Abstract ( 521 )   PDF (782KB) ( 568 )  
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    The reasons and characteristics of the motion blurred image are discussed,the degradation model of blurred images caused by uniform linear motion is analyzed,and the principles of image restoration Wiener filtering are introduced.Due to the uncertainty of fuzzy reason during image acquisition,the point spread function (PSF) is not precise,thus a poor fuzzy image restoration effect.The direction derivation method is used to identify the direction of motion blur,then the first-order differential autocorrelation method to identify blur extent of motion blurred image,hence determining the Point Spread Function.The method of K's automatic estimation algorithm is employed to estimate k's.Experiments show that the method of fuzzy image restoration offers better effect.

    Meteorological Observation Record Management System Based on SQL Server
    HANG Qing
    . 2014, 27(12):  61. 
    Abstract ( 505 )   PDF (622KB) ( 510 )  
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    An information management system of the electronic reporting of meteorological observation records is designed based on SQL Server.The databases consist of the agricultural meteorological database and document libraries.The database storage structure is also designed to facilitate the sharing of meteorological data and geographic information systems.The designed system is capable of database logic design,physical design and operation and maintenance design,and information distribution through network.

    Design and Realization of Wireless Sensor Gateway Applied to Power Systems
    ZHANG Yutian,LAN Haisheng,WU Jixiong
    . 2014, 27(12):  64. 
    Abstract ( 538 )   PDF (545KB) ( 518 )  
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    This paper presents a communication mode based on Mobile Ad Hoc Network (MANET) and ZigBee protocol to address the difficulties of field monitoring in power systems.Information of the sensor node is collected through the coordinator,and transmitted wirelessly through GPRS module attached to ARM,thus providing a precise field monitoring for the operator.The field tests indicate that the design solves the problem of long-range surveillance to a large extent.

    Research on Flow Control System of Extraction Solvent Based on Internal Model
    ZHANG Hongyang,YOU Wen,WU Libin
    . 2014, 27(12):  67. 
    Abstract ( 531 )   PDF (568KB) ( 544 )  
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    The PID controller is incapable of solvent extraction kettle flow compensation in supercritical fluid extraction.The IMC is applied to the control process of the CO2 extraction kettle flow compensation to avoid unpredictable disturbance,thus stabilizing the system CO2-flow compensation.MATLB/SIMULINK simulation of IMC shows that the internal model control is able to control flow compensation precision and feasible for use as the controller of the internal model control system.

    Design and Implementation of Online Auto Trading System
    SUN Xiya
    . 2014, 27(12):  70. 
    Abstract ( 440 )   PDF (561KB) ( 595 )  
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    A design of the online auto trading system and its functional units is presented based on JAVA language,MySQL database,WF framework,Maven private servers,and SCF services.The design concept and the division of functional modules are described.Finally,the system's feasibility is evaluated.

    Design of the High Power Fenestration Control System Based on PLC and Touch screen
    LI Binglin,WEI Hongbo,YOU Wen
    . 2014, 27(12):  73. 
    Abstract ( 623 )   PDF (797KB) ( 555 )  
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    A power window control system of intelligent machines combined with the PLC and touch screen for intelligent building is designed based on PLC high reliability,advanced control technology and touch screen's friendly interface and easy and flexible configuration programming.Satisfactory results have been obtained through simulation experiments and commissioning.The working principles,hardware construction,software program and function characteristics of the designed intelligent window control system are expounded in detail.The design of fire associated control functions,the force power ban when program run overtime,and skylight communication abnormalities alarm are discussed.The design of the intelligent windows control system meets the requirements of modern intelligent buildings with good safety and reliability.

    Research into and Implementation of Mobile Campus Client Based on Android
    DONG Tao,LI Yinfeng,FAN Xingguang
    . 2014, 27(12):  77. 
    Abstract ( 663 )   PDF (985KB) ( 504 )  
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    This paper studies the Android platform framework and related technologies.A mobile campus client based on Android is designed and implemented with HTML5+jQuery Mobile,MySQL,SQlite,etc.Through information exchange and transfer between the client,local data and the Web server and the database,it improves the efficiency of real-time dissemination of campus information and facilitates the intelligence and mobility construction in campus.

    Disaster Emergency Station Based on WiFi Technology and Beidou Satellite Navigation System
    LI Maoyuan,WANG Zhijie,MA Lin,ZOU Wenhui,JIA Hongyu
    . 2014, 27(12):  81. 
    Abstract ( 653 )   PDF (940KB) ( 554 )  
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    In recent years,frequent major disasters around the world have brought great damage.A communication base station that works after a disaster is designed based on WiFi technology and the Beidou satellite navigation system.A wireless AP host is built in the base station after disasters.The affected residents can use their mobile phones or other smart devices to connect the host,and report their information through their mobile browser.Upon receiving the information,the base station server forwards it to the disaster relief command center through Beidou satellite navigation module.

    Design of Real-Time Monitoring Optical Power System Based on STM32
    XU Hongyu,ZHAO Hang,SUN Yanchao
    . 2014, 27(12):  85. 
    Abstract ( 568 )   PDF (761KB) ( 541 )  
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    The optical power of real-time monitoring system is designed on Cortex-M3 32-bit ARM core STM32F103ZE,and the designing principles,implementation,hardware and software structure are given.This article describes the monitored light transferred into digital signal by photoelectric conversion circuit,logarithmic amplifier and AD converter circuit.Then the digital signal is sent to the control unit via field bus for data transmission through GRPS communication module to realize the real-time automatic monitor to the communication cable.Additionally,the design has the advantage of stability,reliability and easy expansion.

    Super Capacitor Characteristics of Manganese Oxide Electrode Materials and Preparation Technology
    HUANG Dengyong
    . 2014, 27(12):  90. 
    Abstract ( 681 )   PDF (469KB) ( 508 )  
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    The preparation of super capacitor and its chemical properties are discussed.Amorphous manganese oxide electrodes are prepared and placed in the electrolyte.The cyclic voltammetric curve in certain scope of potential is mapped.Its reversibility is also analyzed by discharging the electrode in certain electric current.Test results show that the charging and discharging performance of the electrode is good,and with ideal reversibility.

    Phase Estimating Method in Optical MPSK Transmission System Based on Wavelet Transform
    YU Yao,ZHANG Kewei
    . 2014, 27(12):  92. 
    Abstract ( 522 )   PDF (660KB) ( 492 )  
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    In optical M-ary phase shift keying (MPSK) transmission systems,phase noise affects system performance seriously.Filters are widely used as a phase estimating method currently,which has boundary effect and trade-off between high accuracy and lag.A novel feedforward phase estimation method with wavelet transform is proposed to avoid these effects.The simulation results show that the new method can eliminate bit error rate (BER) deteriorating due to 4 MHz laser linewidth or 35° laser phase offset,and is more suitable for high speed coherent optical communication systems to achieve parallel processing.

    Dynamic Optimization and Analysis of Photovoltaic Cells Panel Angle
    ZHAO Xinxu,DING Shaoting,WANG Yikang
    . 2014, 27(12):  96. 
    Abstract ( 695 )   PDF (680KB) ( 447 )  
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    〗The model of PV panel optimum tilt angle with the change of radiation intensity is built based on a city's hourly meteorological data in typical meteorological year,in an attempt to receive the maximum annual amount of radiation per unit area.Simulation results show that the optimum tilt angle of the corresponding period has a remarkable influence on the solar radiation in the same district.Compared with the monthly fixed optimum tilt angle,the daily fixed tilt angle can receive 57.13% more of solar radiation.

    Thin-film Resistor Reliability Characterization Based on Low Frequency Noise
    WU Yong,MA Zhongfa,DU Lei,HE Liang
    . 2014, 27(12):  100. 
    Abstract ( 682 )   PDF (1193KB) ( 518 )  
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    The low-frequency noise of thin-film resistor and its inner defects are closely related.In this paper,the low-frequency noises of a batch of 1.5 kΩ NiCr thin-film resistors both before and after ageing are measured by a testing setup comprised of two-stage low-noise amplifiers and a high speed and high accuracy PCI data acquisition card.Electro-migration inside the thin-film resistor is identified to be the dominant degradation mechanism by a combination analysis of both low-frequency noise and microscopy.The parameters of low-frequency noise such as amplitude,frequency index and turning frequency exhibit unusual fluctuations right before the occurrence of electro-migration.It is concluded that the low-frequency noise of thin-film resistor can sensitively manifest the damages inside the component,and as a result,low-frequency noise can be used as an indicator for non-destructive screening.

    Design of Intelligent Solar Street Lights Based on Single Chip Microcomputer
    ZHANG Keer,HOU Yupeng
    . 2014, 27(12):  105. 
    Abstract ( 815 )   PDF (598KB) ( 702 )  
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    This paper designs a solar street lamp controller with combined time and light control to offer super brightness and haze penetration.The lighting time is controlled by single chip microcomputer STC12C2051 and clock chip DS1302,light on/off settings are stored in memorizer AT24C02,and photoelectric control is realized using photosensitive resistors.The intelligent control system consists of the battery,high brightness LED,overcharge and overdischarge modules.The propose lighting has the advantages over traditional lighting of few moving parts,long service life,low noise,high energy efficiency and good directionality.

    Design of PCI Express Application Platform Based on FPGA
    LI Xiaolong,MENG Lilin,SHAO Ruirui,ZHANG Xiaolei
    . 2014, 27(12):  108. 
    Abstract ( 838 )   PDF (667KB) ( 573 )  
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    PCI-E interface is the third generation computer I/O interconnect standard with high-speed and high bandwidth characteristics.According to the requirements of high-speed data transmission system,a data transmission and processing application platform for PCI-E bus is designed and implemented based on the FPGA PCI-E hard IP.Three data transmission modes are given and tested in Windows XP operating system.The experimental results indicate that the platform functions well with a unidirectional speed up to 7.12 Gbit·s-1,suitable for application in high-speed data transmission system for PC.

    Influence of Obstacles on Antennas
    ZHU Wenjun
    . 2014, 27(12):  112. 
    Abstract ( 573 )   PDF (524KB) ( 721 )  
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    The influence of obstacle in sizes on different types of antennas is simulated using of the software FEKO based on the study of the radiation pattern,with the influence of an obstacle was given in the unit of dB.It is of practical value in the choice of location and type of shortwave antennas.

    A Miniaturized Dual-frequency Circularly Polarized Microstrip Antenna for Beidou and GPS Applications
    CHEN Zhaofeng,PAN Jin
    . 2014, 27(12):  116. 
    Abstract ( 786 )   PDF (861KB) ( 725 )  
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    A compact dual-band circularly polarized patch antenna for both Beidou Navigation System B3 band (1 268 MHz±10 MHz) and Global Position System L1 band (1 575 MHz±2 MHz) is proposed in this paper.Two stacked microstrip layers are employed in the antenna structure to implement the dual-frequency operation.By selecting the material with relative dielectric constant of 9.7 and embedding slots in the patch surface,the size of the required antenna can be reduced and miniaturization can be achieved.Good right-hand circular polarization (RHCP) contributes to truncating corners in the square patch.FEM based HFSS is used for the simulation and parameters optimization analysis of the antenna structure.The simulation results show that the antenna has 3 dB AR BW of 0.5% and 2.2% impedance bandwidth (VSWR<2) in the B3 band.In the L1 band,the antenna achieves 3 dB AR BW of 0.5% and 3.1% impedance bandwidth (VSWR<2).All the simulation results meet the Beidou and GPS applications very well and the antenna has a good application prospect.

    Design and Simulation of a Tri-band Planar Inverted F-shaped Antenna for Mobile Phone
    ZHAO Yifei,YANG Yang,ZHAO Yimin
    . 2014, 27(12):  120. 
    Abstract ( 622 )   PDF (660KB) ( 556 )  
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    There are many methods for the miniaturization and multiband of built-in antennas for Mobile Phone.The folding method is adopted to realize miniaturization,and the tri-band is achieved by double U-shaped slots in the paper.Finally,a new type structure of Tri-band antenna is designed with planar inverted F-shaped antenna.The structure has the advantages of simple design and implementation.The design of antenna can meet the demand of terminals of modern wireless communication systems.

    Motor Brake System Power Supply Design Based on SG3525
    ZHU Hongchao,ZHANG Ying,WANG Lichao,LI Chenglong
    . 2014, 27(12):  123. 
    Abstract ( 625 )   PDF (693KB) ( 537 )  
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    This paper introduces a design scheme of SG3525 controller as the core of the braking system power supply for the current defects of braking system power supplies.The main structure of SG3525 is described and its characteristics and working principle analyzed.The design method and principle are given.The simulation result shows that the system has a higher reliability and stable output voltage.This design has extensive application prospects in the future.

    Application of Wavelet Transform in Power Grid Fault Diagnosis
    WANG Rui,SHI Weifeng
    . 2014, 27(12):  128. 
    Abstract ( 632 )   PDF (801KB) ( 541 )  
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    Fault characteristics are important information of fault diagnosis,and great effort has been put to find a method for their extraction.In this paper,wavelet transform is used to analyze the transient signals of the fault information in an example power system simulated by simpowersystem of MATLAB and to extract the characteristic signal from the transient signals of the faults.The result shows that the RMS value extracted by the method of wavelet transform has a clear mapping relationship with the short-circuit faults,thus its value of applications in power grid fault diagnosis.

    A Method for γ Correction of LED Display Screen
    NIE Bailing
    . 2014, 27(12):  131. 
    Abstract ( 546 )   PDF (679KB) ( 512 )  
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    The gray scale distortion of LED display screen results from the difference between optical and electrical characteristic property.The gray scale correction formula suitable for photo-electrical characteristics of LED and visual bright characteristics are studied based on human visual characteristics,and a method for γ correction based on look-up table is introduced.The realization of γ correction inside FPGA is given.LED display screens achieve better image effect by the proposed correction method.

    Research on Miniaturization Comb Spectrum Source With High Flatness and Narrow Stepping
    SHU Angang,QIN Weiwei
    . 2014, 27(12):  134. 
    Abstract ( 725 )   PDF (813KB) ( 466 )  
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    An efficient comb spectrum source with high flatness,narrow stepping and low cost is designed in this paper.The frequency source adopts high speed digital counter to produce pulse signal,with comb spectrum from 10 kHz to 300 MHz achieved.The comb spectrum source compensates the disadvantages of traditional SRD (Step Recovery Diode) of low efficiency and poor flatness at low frequencies,such as characteristic indexes step of 500 kHz,and a flatness of 1.8 dB within 20 MHz bandwidth.

    An FPGA Implementation Structure of Digital Group Demultiplexing
    HUI Tengfei,YANG Lei,GONG Xianfeng
    . 2014, 27(12):  137. 
    Abstract ( 569 )   PDF (865KB) ( 496 )  
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    This paper studies an algorithm of digital group demultiplexer and its FPGA implementation structure.The mathematical description of demultiplexing algorithm is presented,an FPGA implementation structure is proposed,and a hardware platform is built to test the algorithm.The implementation results show that this structure has a low hardware complexity,which can be used effectively in the implementation of digital group demodulators.

    An Improved DL-CoMP-MU Limited Feedback Scheme
    ZHAO Xin,WANG Junxuan,DING Shuwen
    . 2014, 27(12):  142. 
    Abstract ( 695 )   PDF (900KB) ( 573 )  
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    The theory of matched filter and the ideas of the cognitive approach are used to determine the cooperative transmission structure in order to improve the feedback ability of the existing CoMP downlink link and reduce the feedback overhead.The substitution of the interference signal noise ratio (SINR) feedback overhead solution for the CQI information reduces the amount of feedback information,and further reduces the quantization error of feedback information.Simulation shows that the improved feedback scheme further reduces the feedback overhead compared with the traditional scheme of feedback in raising accuracy.

    Design of a Fast Adaptive Equalizer for Underwater Acoustic Communication
    QIU Zheng,JIANG Chuou,PAN Yuanzhang
    . 2014, 27(12):  147. 
    Abstract ( 524 )   PDF (710KB) ( 643 )  
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    The equalization of channels is a key technique for conquering ISI in modern underwater acoustics communication system,and the improvement of the performance of equalizers is a hot topic.The paper designs a decision feedback equalizer to meet the time-varying channel equalization requirements,and derives an improved CMA blind equalization algorithm utilizing the variation of MSE in order to solve the contradiction between convergence speed and residual error.The results show that the improved algorithm improves greatly both in performance and in equilibrium effect and have better application value in the actual underwater communication.

    A New Method To Improve Radar HRRP automatic Recognition and Rejection Performance
    WANG Jinzhang,GONG Rujiang,REN Jie,YANG Ou,LIU Xiankang,WEI Cunwei,SUN Fei
    . 2014, 27(12):  150. 
    Abstract ( 722 )   PDF (736KB) ( 477 )  
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    The traditional radar HRRP automatic target recognition algorithm to identify the sample rate is low and rejection of the outside samples is not ideal.This paper propose a new method to identify data preprocessing and child like space-based.On one hand,the method of data preprocessing eliminate the effect of noise,on the other hand,through the establishment of sub-like space,the recognition rate of the inside library of samples is improved,and the introduction of threshold based on hypothesis testing theory improves the rejection performance.Experiments show that this method is not only superior to the traditional algorithm in the recognition rate,and can effectively resist the library outside the sample sentence.

    Audio Signal Processing Method Based on AGC Algorithm and its FPGA Implementation
    ZHANG Bo,LIU Yanzhu
    . 2014, 27(12):  155. 
    Abstract ( 771 )   PDF (505KB) ( 551 )  
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    In the speech communication system,the interference in receiving speech and audio information and other sources of instability factors need to be overcome for accurate and clear voice information.This paper studies the audio signal processing method based on AGC algorithm and its FPGA realization,and sums up the audio signal processing method based on practical AGC algorithm and FPGA implementations,which can reduce the degree of distortion of the audio signal,and significantly increase the stability of the audio signal output.Experimental results show that the application of AGC algorithm in audio signal processing and FPGA implementations offer good performance.

    Design and Implementation of Remote Electric System Based on FPGA
    PANG Yuefeng,DU Yong,ZHU Weiwei
    . 2014, 27(12):  158. 
    Abstract ( 694 )   PDF (753KB) ( 457 )  
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    For the construction of remote measurement and control equipment,a design of electric power order code check and feedback mechanism is given,and the key technologies of data transmission and reception,state exception handling,instruction code processing,and clock generating function panel are described.The remote electric control board platform is built with FPGA as the core device,and software for remote electric control is developed.Practical use verifies the good performance and stability of the proposed remote charging system.

    Design of the Measurement and Control Interface of Digital Sweeper Based on USB
    SUN Yuanyuan,LI Yao,MA Zewei
    . 2014, 27(12):  162. 
    Abstract ( 603 )   PDF (809KB) ( 455 )  
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    The measurement and control interface technologies of Digital Sweeper and USB2.0 are briefly introduced,and a design of control interface of digital sweeper and its main software flow are given.The USB access and storage module of the test data of sweeper is implemented by programming on DSP.The test results of the sweeper is displayed and processed online on computer,which show that the design meets the requirement.

    Conversion-based Approach to Optimization of Quantum Cost of Reversible Logic Circuits
    FANG Cong,ZHAO Shuguang,XIA Kaixiang
    . 2014, 27(12):  166. 
    Abstract ( 556 )   PDF (584KB) ( 405 )  
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    Optimization of the circuit is one of the key problems in synthesis of reversible logic.In view of the high complexity and poor scalability of the reversible logic circuit optimization algorithm,with the most common reversible logic circuit whose components is Toffoli as an example,the relationship between adjacent logic gates is analyzed,the mobile rules and simplification rules for this kind of circuit neutron sequence are presented,and then effective method using template matching algorithms to optimize reversible logic circuits are proposed.Benchmark tests on the circuit show that the proposed method cuts the cost of reversible logic circuit construction by partly decrease the number of reversible gates and the control digits.

    Influence of Series Compensation Capacitor on Transmission Line Protection
    JIA Xinya
    . 2014, 27(12):  170. 
    Abstract ( 621 )   PDF (541KB) ( 507 )  
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    the series compensation capacitor can effectively reduce the line is connected between the reactance value,improve the stability and maximum transmission power system operation,reduce the engineering cost of transmission system.In this paper the effect of series compensating capacitors on line protection device is studied,analysis of the causes of the problem,find a solution to the problem.Finally,put forward some specific measures to eliminate the influence of series compensation capacitor.

    Design of a Simulator Based on SST89C58
    WU Zhao
    . 2014, 27(12):  172. 
    Abstract ( 548 )   PDF (546KB) ( 460 )  
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    A simulator based on SST89C58 microcontroller is designed,and the composition of the circuit is given.The system realizes the switch between simulator offline operation and simulation running functions.The dynamic measurement of the level in the circuit is performed for the estimation of signal frequency and duty ratio.

    Design and Realization of Tax Algorithm Encryption Card Based on FPGA
    SU Zhenyu
    . 2014, 27(12):  175. 
    Abstract ( 504 )   PDF (868KB) ( 635 )  
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    A tax algorithm encryption card based on FPGA is designed for the demand of tax invoice identification in the field of taxation.FPGA is the kernel unit of this card and it utilizes embedded PCI-IP core to realize the interface logic of PCI bus.FPGA makes tax cryptographic algorithm chips function efficiently by using Finite State Machine and it realizes the fast transmission of data with the DMA controller.This device is applied in tax department and it encrypts and stores data correctly.

    Physical Education Based on Electronic IT Environment
    SONG Baojie
    . 2014, 27(12):  179. 
    Abstract ( 538 )   PDF (436KB) ( 451 )  
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    For the use of electronic information technology college physical education,which can effectively improve teaching efficiency.Application of computer multimedia technology,can effectively improve the students' interest,optimization to improve the quality of teaching in the classroom.The paper will be in the application of electronic information technology meaning the current college sports teaching,and put forward some constructive suggestions on this basis,for reference.

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