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Table of Content

15 September 2011 Volume 24 Issue 9
  
    Articles
    Long Distance Radio Frequency Identification System Fusing Wireless Sensor Network
    LI Hui-Zhen
    . 2011, 24(9):  1. 
    Abstract ( 1438 )   PDF (822KB) ( 1226 )  
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    The significance and practical project of RFID technology fusing WSN has been studied,in which "smart node" is adopted to complete acquisition,transmission and recognition of the information,making full use of the advantages of RFID information identification and the WSN of low cost,long distance etc,in order to extend RFID coverage area.The results of the study show that RFID and WSN are highly complementary,and it is of great importance to study the fusion of RFID and WSN and it should further expand the application of IOT in width and depth.

    Analysis and Optimization of PTS Algorithm for Reducing PAPR of OFDM Signal
    HU Mao-Kai, CHEN Xi-Hong, LIU Qiang
    . 2011, 24(9):  4. 
    Abstract ( 1432 )   PDF (745KB) ( 936 )  
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    PTS (Partial Transmit Sequence) is an effective algorithm for the reduction of the high peak-to-average ratio (PAPR) of OFDM signal.But its application is limited for its high computational complexity.This research on the PTS algorithm covers IPTS,sliding window search PTS,Sub-block combined division PTS,Hadamard-PTS,m-sequence PTS,pso-PTS,and their algorithm performances are carried out.Then two PTS syncretic algorithms are proposed to improve the performance.The simulation results show that the syncretic algorithm is of low computational complexity and can restrain the high PAPR effectively.

    Algorithm for Image Interestring Point Detection Based on Improved SUSAN Operator
    GUO Feng, WANG Dao-Ping, HAN Ming
    . 2011, 24(9):  9. 
    Abstract ( 1436 )   PDF (585KB) ( 1327 )  
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    SUSAN edge detecting operator is an edge detection algorithm based on comparison of the image gray.This article introduces the principle of the operator,and improves the gray Threshold.The initial value of threshold is calculated in every single SUSAN template.Final value of threshold is obtained using iterative segment,which makes it possible to pick up the right interesting point in all kinds of gray contrast.The results show that the algorithm has the advantages of simplicity,strong anti-noise,and small amount of calculation.

    Analysis and Calculation of HF Ground-wave Communications Link
    WANG Yao-Hai
    . 2011, 24(9):  12. 
    Abstract ( 1408 )   PDF (479KB) ( 1192 )  
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    Short-wave communications generally adopt ground-wave with whip antenna in mobile communications and carry-out communication.To assess the short-wave ground wave propagation,wave propagation model and antenna simulation technology are combined to calculate whip antenna radiation property with method of moments.Results show that there is an optimum frequency band corresponding to different communication distances.

    On Cognitive Radio Spectrum Sensing Technique in Femtocell System
    ZHAO Zhi-Yuan
    . 2011, 24(9):  15. 
    Abstract ( 1336 )   PDF (777KB) ( 851 )  
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    Femtocell technology was suggested for solving the indoor coverage of 3G networks.With the application of this technology,the indoor signal quality can greatly improve.As the Femtocell system uses the same spectrum resources with 3G systems,it can apply cognitive radio spectrum sensing technique to solve the reuse problem of spectrum resources.The background of this paper is TD-SCDMA system.This paper analyzes the principle of spectrum sensing,shows the steps of sensing and presents the method for improving the accuracy of spectrum sensing.

    The Study of Highway Illegal Parking Real-time Detection Algorithm Based on Video
    ZHANG Bei-Bei, WU Qi-Sheng
    . 2011, 24(9):  20. 
    Abstract ( 1555 )   PDF (735KB) ( 932 )  
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    Illegal parking of vehicles is an important incentive for highway incidents.Expedient and reliable illegal vehicles detection is a top priority of expressway traffic management and control.This paper presents a real-time highway vehicle parking detection algorithm based on video.First of all,the video-based detection system consists of illegal parking and the advantages of video detection are analyzed;then background subtraction algorithm and OSTU threshold method are combined to judge whether the vehicles is parking illegally.Experimental results show that the method has good results.

    An Improved Algorithm for Reducing PAPR of OFDM System
    GAO Tian, LI Guo-Min
    . 2011, 24(9):  24. 
    Abstract ( 1648 )   PDF (600KB) ( 1011 )  
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    SLM (Selected Mapping) is an effective algorithm for reducing peak-to-average power ratio (PAPR) of OFDM system without distortion.To reduce PAPR of OFDM system,a method for reducing PAPR based on SLM combined with counter-balance technology is proposed.This method uses improved SLM scheme to optimize the performance of PAPR in multi-carries system,then a group of sampling signals are used as reference signals to reduce PAPR.The principles of SLM and peak cancellation are analyzed.The simulation results shows that the PAPR performance of this method has lower PAPR with lower complexity and bit error rate compared with the original SLM.

    Model Design and Debugging of Recursion Algorithms
    CHEN Bao-Ping
    . 2011, 24(9):  28. 
    Abstract ( 1203 )   PDF (460KB) ( 913 )  
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    In this paper,a universal model design of recursion algorithms is given.Several typical examples illustrate its usage and effectiveness.In addition,some methods and techniques of debugging are introduced.

    Design of Compact Full Bridge DC-DC Isolated Power
    WANG Qiu-Yan, LIU Yan, LI Shu-Yan
    . 2011, 24(9):  30. 
    Abstract ( 1333 )   PDF (621KB) ( 878 )  
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    The integrated half bridge IGBT driver requires compact,high efficiency and high power density isolated DC-DC power supply.In this paper,a set of two magnetic cores share a high-frequency full-bridge switches is designed.A simple circuit generates four channel drive signals,without isolation,to achieve compact on-board power supply and the best combination with the integrated half bridge IGBT driver.The key signals are simulated,and experimental results show that the power supply is simple and reliable.

    Design of 2.4 GHz Microstrip Antenna Based on CC2430
    YANG Yong-Xia, YANG Lin
    . 2011, 24(9):  34. 
    Abstract ( 1428 )   PDF (1111KB) ( 982 )  
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    This paper presents a solution to the shortcoming of large size and high power consumption of upright antenna.The solution uses the microstrip antenna in place of the traditional upright antenna.The radiation principle of microstrip antenna is discussed,and the entire design procedure of the microstrip antenna at frequency of 2.4 GHz is introduced.First,according to the requirements of the materials,the shape and the type of the microstrip antenna are determined,and the size of the antenna is determined according to the formula and software calculated results.And then the antenna model is built and simulated in ADS (Agilent).Finally the best antenna parameters are obtained through the optimizing and matching in order to make the antenna characteristics comply with the design requirements.

    A 1.2 V CMOS Analog Multiplier Based on Dynamic Threshold Voltage NMOS Transistor
    CHENG Wei-Dong, ZHU Zhang-Ming, WANG Lei
    . 2011, 24(9):  38. 
    Abstract ( 1272 )   PDF (584KB) ( 868 )  
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    This paper analyses an analog multiplier based on dynamic threshold voltage NMOS transistor for two input transistor.Four dynamic threshold voltage NMOS transistor and two active resistors are used to design a novel 1.2 V low power CMOS analog multiplier.The number of input transistor has been decreased and the biased transistor and circuits have been saved,while the performance is appropriate.The main characteristics are that the margin between the first order harmonious wave and the third order harmonious wave of the output wave is about 40 dB,that the output frequency bandwidth is 375 MHz,and that the average power supply current is 30 μA.The novel analog multiplier can be applied for the design of low power communication integrated circuits.

    Design and Implementation of White-light LED Driving Circuit
    JI Jia, DENG Zhou-Hu, HOU Ming-Yue, QI Wen-Tao
    . 2011, 24(9):  42. 
    Abstract ( 1517 )   PDF (570KB) ( 909 )  
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    Through the analysis of the electrical characteristics of LED and its work characteristics,a high power efficiency PWM mode white LED driver circuit based on the HV9910B chip is designed,and the operating frequency of the circuit is determined through theoretical calculations and experimental measurements.Test results show that the driver circuit has a wide operating voltage range,constant current output,and a conversion efficiency of over 85%.

    Design of Electrochemical Workstation Based on MCU AT89C52
    YANG Jing-Jing, LUO Zheng-Wen, LIU Yan, MU Xiao-Gang
    . 2011, 24(9):  45. 
    Abstract ( 1254 )   PDF (734KB) ( 985 )  
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    An electrochemistry workstation based on electrochemistry theory is developed.The electrochemistry workstation comprises a signal generator,a potentiostat,a data collection part,a MCU and a host IPC (industrial PC).The workstation can control and measure signals in an electrochemistry system such as current,and potential.It also can realize a cathodic protection function.Compared with the conventional electrochemistry workstation,the workstation adopting an advanced integrated circuit has the advantages of small system error and favorable performance.Furthermore,the workstation is provided with favorable performance in the aspect of cathodic protection,thereby having better application and favorable market prospect.

    Development of X-Band Solid-state Power Amplifier
    YANG Jun-Li, ZHANG Yan-Ni, MA Jun-Ge, DANG Zhi-Guo
    . 2011, 24(9):  48. 
    Abstract ( 1288 )   PDF (641KB) ( 1127 )  
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    A new successful developed x-band solid-state power amplifier is introduced.The amplifier operates in pulse mode by taking 4 pieces of final stage power modules,each of them has output of 30 W to carry out power synthesis so as to get the peak power of more than 80 W.Its maximum pulse width is 200 μs and the maximum duty cycle is 40%.The tested result shows that no matter the output power,size or the reliability has been improved greatly.

    Interface Design and Implementation for FPGA Incremental Encoder
    HUAN Bao-Gui, LEI Bin, WANG Peng
    . 2011, 24(9):  51. 
    Abstract ( 1538 )   PDF (548KB) ( 1219 )  
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    Optical-incremental encoder,which is also called photoelectric anger-position sensor,is the core of device in measurement of motor speed and rotor position in driver system.The article researches on the incremental photoelectric encoder and analyzes its four fold frequency multiplication principle.It gives a method based on FPGA to multiply the signal of the incremental photoelectric encoder,differentiates its phase and counts its number.It has improved resolving power of coder and realized signal detection and position servo control of high accurate and high stable.The result indicates that the system can effectively eliminate noise and dither.The capability of restraining disturbing is improved.It is heritable and upgradable.

    Design and Application of Energy-Saving and Light-sensitive Controller for The Classroom Lighting
    ZHOU Peng, JIANG Fang-Jian
    . 2011, 24(9):  54. 
    Abstract ( 1004 )   PDF (385KB) ( 998 )  
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    The paper based on photosensitive component and control circuit technology,describes the working principle of a energy-saving and light-sensitive controller and draw a schematic.After the actual test,the controller can be used in classrooms and laboratories lighting system.Play the role in energy saving,environmen protection and extending lamp life.

    Development of Radiation Hardened 1553B Bus Differential Receiver
    JI Qing-Zhou, YANG Li-Hong, XIAO Juan, WANG Xi-Hu
    . 2011, 24(9):  56. 
    Abstract ( 1268 )   PDF (823KB) ( 850 )  
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    The development of a 5 V 1553B differential receiver which can perform anti-radiation and low power is presented,and the receiver can receive the signal on bus.The circuit based on commercial BCDMOS Process can not only filter the noise on bus,but also restrain the common signal.The receiver not only solve the problem of output pulse width,receiving threshold value,unnecessary output pulse and so on,but also lower the power dissipation.In addition,the design reinforces some sensitive parameters about radiation by the design of layout.The test result of the chip shows that the function of the chip is favorable,and can apply extensively to the system of 1553B bus.

    Research on Multi-carrier RF Generator Technology
    LIU Zhan-Xian
    . 2011, 24(9):  59. 
    Abstract ( 1027 )   PDF (871KB) ( 911 )  
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    A 9-channel radio-frequency synthesis of signals is designed,which constitutes a multi-band RF signal source.With the help of the frequency synthesizer and IF modulation chip,the baseband or IF signals could be modulated into RF directly.Finally,the RF signal coupled into nine roads all the way to form multi-band RF signal source.

    Study of Coexistence Interference in WLAN System and TD-LTE System in 2.4 GHz Band
    WANG Kan, YANG Jia-Wei
    . 2011, 24(9):  62. 
    Abstract ( 1378 )   PDF (589KB) ( 999 )  
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    Coexistence of systems brings about the out-of-band interference due to the imperfect characteristics of the receiver and transmitter.Out-of-band radiation of WLAN equipment working in the ISM band may interfere LTE system to a certain degree,therefore,it is necessary to restrict these values.

    Research on and Implement of Direct Sequence Spread Spectrum Communication Based on FPGA
    WANG Dao-Ping, GUO Feng, HAN Ming
    . 2011, 24(9):  66. 
    Abstract ( 1758 )   PDF (887KB) ( 1051 )  
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    The direct sequence spread spectrum communication (DSSS) is widely developed in military and personal mobile communication for its advantages of high noise resistance,low interception probability,multiple-access communication ability.How to implement a direct sequence spread spectrum communication system used FPGA is researched.A DSSS included transmit and receive module is established based on QUARTUS II.The transmit module is combined with PN generator,spread spectrum modulator,the receive module is combined with match filter and de-spread demodulator.The circuit design and its results are given.

    Performance Analysis of MIMO in Troposcatter Communication
    LIU Xiao-Peng, CHEN Xi-Hong, LIU Qiang
    . 2011, 24(9):  70. 
    Abstract ( 1938 )   PDF (471KB) ( 902 )  
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    This paper indicates the bad transmission environment and multipath fading characteristic of troposcatter communication.The basic theory of MIMO is introduced,and its model and channel capacity analyzed.The performance simulation of MIMO in troposcatter communication based on MATLAB/Simulink shows that MIMO could increase the capacity and performance of the troposcatter communication and enhance the reliability of the communication by reducing BER effectively.

    The Design of Iinear CCD Driving Circuit
    HE Min, WANG Dao-Ping
    . 2011, 24(9):  73. 
    Abstract ( 1326 )   PDF (520KB) ( 1027 )  
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    This paper discusses the current status of the linear CCD driving circuit and its working principle.The driving circuit based on CPLD has been selected as driving working program.EPM240T100C5N of MAXⅡdevices is used as the control center.Take TCD1500C for example,linear CCD driving circuit based on CPLD is designed,and the diagram of hardware design completed.Besides,the software debugging is implemented.By QUARTUSⅡsoftware platform,the simulation of this program shows that the linear CCD driving circuit based on CPLD can meet the driving pulse of CCD required.

    Analysis of Nonlinear Circuit Subnet Tearing and Measurability
    WANG Kai, LIU Yan, LIU Li-Qiang, CHENG Li
    . 2011, 24(9):  76. 
    Abstract ( 1192 )   PDF (536KB) ( 791 )  
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    Network torn is a key subject in circuit fault diagnose.This paper pays attention to the partition condition and the analysis of measurability of circuit containing nonlinear component.Study of subnet measurability laid the groundwork for further fault location.

    The Development Prospects of ECG Monitoring Circuit
    SHANG Yu, WANG Wei
    . 2011, 24(9):  80. 
    Abstract ( 1093 )   PDF (657KB) ( 1052 )  
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    This article describes the characteristics and prospects of modern typical ECG monitor.In view of the high impedance,small amplitude and low frequency characteristics of common ECG,the ECG monitor consists of the ECG acquisition module,amplifier module,filter module and processing module.ECG acquisition module and amplifier module are usually determined by the Input Requirements of filter module and processing module.There usually exist large common mode interference signals in the circuits and processing module can not completely filter out the interference signals,so the modern ECG monitor usually use digital filter as a filter module.Processing module generally uses common or embedded computer.The future trends of ECG monitor will be miniaturization,intelligent detection,information diversity and remote diagnosis.

    Application of OFDM in Optical Communication
    LIU Ji-Ye, HU Mao-Kai, CHEN Xi-Hong
    . 2011, 24(9):  83. 
    Abstract ( 1892 )   PDF (719KB) ( 955 )  
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    Optical orthogonal frequency division multiplexing (O-OFDM) is currently a hot topic in optical communication research over the last couple of year.The application of OFDM in fiber optical communication has shown virtues such as high spectrum efficiency,expedient and effective dispersion compensation,reducing system nonlinear markedly and so on.This paper introduces the basic principle,development and relevant research results of O-OFDM,analyses its advantages and problems of applications,and finally discusses several applications of the commercialization of O-OFDM.

    The New Evolution of Digital Private Mobile Radio Systems
    LI Dong-Jie, YANG Jia-Wei
    . 2011, 24(9):  87. 
    Abstract ( 983 )   PDF (1026KB) ( 973 )  
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    Base on the digital mobile radio standards DMR (Digital Mobile Radio) and dPMR (digital Private Mobile Radio) newly released by ETSI,this paper summarizes the evolution of digital Private Mobile Radio in these years.It first works on the origin,technical features,and applications of these two standards,compares them with other standards already available in China,and finally analyzes the future applications of the two standards in China.

    Arc Fitting Technology for Crystalloids Growth Detection System Based on LabVIEW
    BAI Yu, CHENG Guang-Wei
    . 2011, 24(9):  91. 
    Abstract ( 1895 )   PDF (564KB) ( 866 )  
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    In the crystalloids growth detecting system based on LabVIEW,according to the growth features of monocrystalline silicon and the principle of least square method fictions,the image processing is done on collected monocrystalline silicon growth information by adopting graphic programming languages,during which spline curve fitting is applied to some of the "ptroelectric rings".Therefore,the diameter of the crystalloids growth is able to be detected via the Arc fit.This experiment exhibits that such a rigorous design is capable of the spline curve fitting function,and can detect the diameter of the crystalliods growth of monocrystalline silicon,and thus meeting all requirements of detecting system.

    Preparation of Paraffin Microcapsule Phase Change Materials by Insitu Polymerization
    SHAN Xu-Tao, LI Shi-Wei, WANG Fei, ZHAO Wu, YAN Jun-Feng
    . 2011, 24(9):  94. 
    Abstract ( 1203 )   PDF (669KB) ( 977 )  
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    In this paper,we use a copolymer of Urea,formaldehyde and melamine as shell materials,and paraffin wax as core materials of microcapsule by the method of Insitu polymerization to prepare microcapsule structure Phase change control temperature materials.Analytical methods of SEM,DSC etc.are used to characterize the structure and performance of the samples,and thereby obtain the major influencing factors of microcapsule performance and optimize the Preparation process conditions.

    Combination of Distributed Optical Fiber Sensing Technology and PON
    MA Cai-Hong
    . 2011, 24(9):  97. 
    Abstract ( 1354 )   PDF (1049KB) ( 875 )  
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    Theories,applications and key technologies of distributed optical fiber sensing system and PON are studied.The integration of distributed optical sensor network into PON is proposed,which is the future trend of optical fiber sensing and optical fiber communication.Aiming at the application of distributed optical sensor network in the security field,a fusion solution with EPON is put forward,integrating the OTDR technology into EPON for fiber optic fault detection and location.Experiments show that the approach is feasible.

    The Application of Space-Time Coding in OFDM System
    ZHANG Wei-Gang, SHANG Yu
    . 2011, 24(9):  101. 
    Abstract ( 1798 )   PDF (492KB) ( 937 )  
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    This paper studies the three typical space-time coding technology: the space-time layered code (LSTC),space-time block codes (STBC),and the space-time grid code (STTC);and discusses their coding and decoding principle.With emphasis on space-time block code,the OFDM systems are introduced in detail.The basic principle of the space-time block codes and OFDM technology combining STBC-OFDM system of basic model are discussed.A theoretical analysis is made of the receiver SNR performance,and a comparison is made through MATLAB simulation of ber performance with different numbers of antenna.The reliability of the STBC-OFDM system is validated.

    Adaptive Multi-scale Wavelet Edge Detection of Super Vacuoles Image
    LEI Bin, HOU Shuai-Ge, SHEN Yan-Hui
    . 2011, 24(9):  104. 
    Abstract ( 1553 )   PDF (806KB) ( 906 )  
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    Aiming at the undesirable noise in the image of Super Vacuoles image,which is acquired from the high-speed projectiles test underwater,and the poor ability of traditional edge detection algorithm to restrain the noise in auto edge detection,this paper uses the self-adaptive multi-scale wavelet edge detection to detect the edge of Super Vacuoles image.First,we carry out the multi-scale wavelet transform and the enhancement of neighboring scale gradient.Then,we use the K-Means clustering to auto detection the edge,after which we obtain the edge of different scale.Finally,we choose the Multi-scale fusion strategy according to the wavelet and fuse the multi-scales edge into the final edge.The Experiments show that compared with the traditional edge detection algorithm,the proposed algorithm suppresses the edge noise more effectively,and obtains more information of the edge.

    Design of TD Wireless Data Acquisition Terminal of Coal Mine Underground
    ZHANG Xiao-Li, LIU Lei
    . 2011, 24(9):  108. 
    Abstract ( 1338 )   PDF (653KB) ( 826 )  
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    According to the status of coal mine underground communication,a scheme of the underground wireless network is proposed.The feasibility of using TD-SCDMA technology through trial study of the simulation of tunnel in underground wireless communication is demonstrated,on the basis of which the mine wireless data acquisition Terminal based on TD-SCDMA technology is designed and implemented.The Terminal uses TD terminal module LC6311 (+) as the communication platform to realize fast,long-distance transmission of acquisition data,which is ideal for coal mine detection system.The interface communication circuit of the platform and MCU is also given.

    Application of Turbo Code in High Frequency Communication
    HUANG Wei, XU Jian, ZHAO Shi-Tao
    . 2011, 24(9):  111. 
    Abstract ( 1368 )   PDF (647KB) ( 812 )  
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    To deal with serious interference in HF radio channel,an efficient channel coding is proposed in this paper.The principles of RS codes and convolution codes usually used in HF radio are described,and Turbo code that is close to Shannon limit is introduced.Computer simulation and performance comparison is conducted.The simulation results show that Turbo code has strong error-correcting ability at low SNR,and it can effectively reject the interferences when applying it in HF communication system.

    Body Movement Model Based on Video Capture System
    ZHANG Jun, DENG Zhou-Hu, DANG Dan-Heng, YUN San-Ni, FENG Xiao-Hai
    . 2011, 24(9):  114. 
    Abstract ( 1751 )   PDF (696KB) ( 803 )  
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    In order to study the human motion model,a limbs movement pattern acquisition system is designed which consists of PCI-1411 video capture card and the digital image processing platform based on LabVIEW machine vision.This research sets up the mathematical model motion of relevant limbs through processed video frames of the limbs movement,and obtains the accurate parameters of limbs movement.The results show that the movement model established by the video capture technology has the advantages of higher accuracy,faster processing speed,less system error,and easy analyzing and processing function over the models based on sensors acquisition technology.

    Design of H.264 Video Compressing Based on Android System
    ZHANG Guang-Yao, GUO Yong-Qing, CHEN Yang
    . 2011, 24(9):  117. 
    Abstract ( 1496 )   PDF (646KB) ( 949 )  
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    This paper proposes a technical design of H.264 Video Compression based on Android platform.The terminal design of this scheme is based on the hardware platform of S3C6410 processor and software platform Android version 2.3.Through the graft of webcam USB driven on the terminal platform,the video images H.264 standard compression and Socket network programming,the Real-time display of network video monitor is realized.

    Design of Data Processing and Transmitting System of Gyroplane for Police
    SU Ke-Duo, ZHANG Bo-Hu, DING Qian-Qian
    . 2011, 24(9):  121. 
    Abstract ( 1461 )   PDF (527KB) ( 897 )  
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    The small unmanned gyroplane is used as bench of the system of police gyroplane,which is mainly applied to implement service and interchange the emergency on-site reconnaissance and surveillance.Data processing and transmitting system is composed of controlling sub-system which is benched by gyroplane and another sub-system where video information is collected,processed and transmitted.The block diagram of controlling system and video data interface of collecting and processing module are described in this papar.In the module of Video,SAA7111A and Hi3510 are selected as chips which can process and compress video respectively.Data transmitting is done by wireless WIMAX module with high-bandwidth.

    Design of Signal Acquisition and Processing System Based on Microphone Array
    XU Jia-Long, ZHANG Yi-Wen, LIU Jian-Ping
    . 2011, 24(9):  124. 
    Abstract ( 1602 )   PDF (588KB) ( 1148 )  
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    A signal collecting and processing system based on TMS320C6713 is introduced in the paper.The system uses TMS320C6713 as the core controller,connecting with PCM4204 through McASP of the controller.The system can take the full advantage of multiple thoroughfares,design the collecting and processing platform of the microphone array with 16 thoroughfares,and realize data transmission via the external USB chip,facilitating data processing with PC.Due to large quantity of sampling data,better synchronicity,high precision,high-speed data transmission as well as fine reliability,this system can offer a more efficient original data to all kinds of the microphone array application.

    Fault Diagnosis of Hydraulic Systems Based on Virtual Instrument and BP Neural Network
    GONG Shui-Qing, WANG Wai
    . 2011, 24(9):  128. 
    Abstract ( 1596 )   PDF (585KB) ( 882 )  
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    The difficulties of analysis and detection,the cost of time,the low veracity of estimation was found in diagnosis for hydraulic system.Then a design scheme of fault diagnosis for hydraulic system was put forward.Through the function of powerful abilities to collect,analyze and deal with the data,the long-distance survey of hydraulic system was realized.Through the analysis of historical data by using BP neural network,the forecast of future state was achieved.A favorable interface of software,simple operation,high veracity and beneficial practical value are the most obvious characters of this method.

    Motion Control of Omni-directional Robot Based on Fuzzy PID Control
    TIAN Qi, LI Qi, YAO Peng, ZHAO Yuan
    . 2011, 24(9):  131. 
    Abstract ( 1571 )   PDF (686KB) ( 903 )  
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    Through analysis of the kinematics model of soccer robot,with time change,nonlinear and other characteristics of this system in consideration,a control method combining fuzzy control with traditional PID control is presented.To solve the problems of robot soccer motion system,the methods of dynamically regulate the three PID parameters (kp,ki,kd) based on fuzzy control is proposed.The improvement of control effect is verified by experimental result.

    Design of Automatic Testing System Based on AXIe Bus
    XU Jian-Feng
    . 2011, 24(9):  134. 
    Abstract ( 1067 )   PDF (596KB) ( 844 )  
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    Automatic testing system (ATS) is applied in industry,aerospace and automatic weapon widely.The trend of ATS development is standard,modular and serial production.The bus is the key basis for ATS.The advantages and disadvantages of the bus PXI and LXI are analyzed and a new ATS based on the new bus AXIe is introduced.

    Signature Verification System Based on Writing Pressure
    MEI Jian, HUANG Yong-Liang, CHEN Cong, MAO Wei
    . 2011, 24(9):  136. 
    Abstract ( 1676 )   PDF (703KB) ( 733 )  
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    In this article,a system of signature verification based on writing is introduced.We employ the touch-screen controller AD7879 to get the accurate writing pressure,and then use the MCU of 80C51 to transfer the data of the coordinates and pressure to the LabVIEW to display and process the data.This system achieves better performance of the anticipate function,thus building a safe and efficient system,in which it is very difficult to fake.Overall,this system is simple,stable and highly portable,and has bright future of wide application.

    Research on Kalman Filter in Error Processing of GPS
    LIU Yan-Fei, GUO Suo-Li, HOU Rong-Chang
    . 2011, 24(9):  140. 
    Abstract ( 1578 )   PDF (639KB) ( 657 )  
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    This article introduces the reason and constitute of the GPS error,analyzes the influence of the GDOP,and puts forward a mathematics model of error processing,which adopts the method of the Kalman Filter,The experiment indicates that this method limits the error margin in the GPS effectively and improves the position accuracy.

    Design of Improved MIT Software Phase Detection Unit and Experiments
    ZHANG Hua, JING Xi-Jing, LU Guo-Hua, WANG Hua, LI Wen-Zhe
    . 2011, 24(9):  143. 
    Abstract ( 1803 )   PDF (785KB) ( 906 )  
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    In order to solve the phase difference detection in brain magnetic imaging (MIT) systems,we improve and achieve a phase MIT software platform.Software is LabVIEW2009,and phase detection uses FFT phase detection algorithm;hardware is the NI PXI 5122 data acquisition card of 100 MS·s-1 real-time sampling,and consider the use of electromagnetic security module for the weak gain amplification of small signal amplification.A sampling of high precision,adjustable amplification gain,FFT-based algorithm phase MIT software platform is built.In the simulation experiments of Cerebral hemorrhage phase detection,phase difference increases with the amount of bleeding;and with constant excitation signal power,the phase difference increases with excitation frequency.Phase accuracy improves from the original 0.01 degrees to 0.001 degrees,which indicates that the MIT system could better reflect changes in tissue conductivity.

    Applications of Database Index Technology
    OU Ping
    . 2011, 24(9):  146. 
    Abstract ( 1254 )   PDF (533KB) ( 765 )  
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    As information technology continues to evolve,the amount of information to the explosive rate of increase in the amount of data showing the increasing trend of more and more complex data types,which make it difficult to access.Therefore,it is the primary objective of a database designer to improve the speed of data extraction.This article discusses the database indexing technology,and how to set up an accurate and effective index of database.Specific examples are given to illustrate the co-indexing technology for the database to provide a reference to the database designer.

    Research on the Performance Prediction of Infrared Imaging System Based on Laser Interference
    ZHANG Fang-Fang, RUAN Jiang-Yang, WANG Xiao-Rui
    . 2011, 24(9):  149. 
    Abstract ( 1105 )   PDF (754KB) ( 636 )  
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    More and more counter-measures and equipments are used to disturb the normal working of imaging system,laser interference is one of the most common and effective counter-measures,the effects of laser interference on performance prediction were hardly analyzed.Therefore,the relationship between laser energy absorbed by infrared imaging system and target contrast enhancement is analyzed on the basis of NVThermIP performance prediction model and the quantitative relation between laser energy and contrast enhancement is got,then contrast threshold function of the infrared imaging system is modified.The effects of laser interference on capability of performance prediction is compared and analyzed by NVThermIP model.The results of this research could provide the basis for performance prediction appraisal and theoretical model of infrared imaging system.

    Design and Implementation of WMA Audio Playing in Android System
    BAI Lu, LI Guo-Min
    . 2011, 24(9):  154. 
    Abstract ( 1798 )   PDF (706KB) ( 909 )  
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    In order to enhance the function of multimedia system of Android system,a WMA audio player is added to the Android system in intelligent mobile phones.By creating an analysis unit of file format and decoding unit based on Stagefright frame in Android system,a WMA audio player is designed and implemented that can correctly decod WMA data into PCM data.The test results show that it can play WMA audio on real phone successfully with good sound effect.

    Papers Remote Processing System Design of Edition Department Based on the Browser/Server
    WANG Xiao-Fang, LI Rui-Gang
    . 2011, 24(9):  158. 
    Abstract ( 1478 )   PDF (445KB) ( 645 )  
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    A remote papers processing system based on ASP is introduced.This system is supported by Access databases and uses the dynamic homepage ASP technology as main development platform.Based on the actual demand of our college,a remote papers processing system based on the browser/server two-layer structure is designed.This system realizes a series of functions such as the author online contribution/inquiry,editor's online edition/choice experts,sending papers to expert,and expert's online assessing and so on.

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