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15 January 2012 Volume 25 Issue 1
  
    Articles
    A Current Sensing Circuit for High-power LED Driver Using Hysteresis Current Control
    SUN Zheng-Min, CHEN Hou-Peng, WANG Qian, LUO Sheng-Qin, SONG Zhi-Tang
    . 2012, 25(1):  1. 
    Abstract ( 1198 )   PDF (777KB) ( 930 )  
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    A high-performance current sensing circuit for the high-power LED driver using current control is proposed.It is a high-side current sensing circuit using high voltage process and can withstand up to a 40 V input voltage.By analyzing the characteristics of hysteresis control and using the series-sense resistor sampling technology and matched current source structure,the circuit reduces the complexity while ensuring the response speed and sampling precision.An input voltage compensation circuit is also added to improve the precision of current control.The simulation results in Cadence show that the circuit can work correctly when the operating frequency is 800 kHz.The current sensing accuracy can be up to 99.78%.When the input voltage changes from 15 V to 35 V,the average load current error is as small as 0.81%.The output voltage ranges from 0 V to 5 V.

    Impedance Matching Circuit Principle and its Application
    TIAN Ya-Peng, ZHANG Chang-Min, ZHONG Wei-Wei
    . 2012, 25(1):  5. 
    Abstract ( 1131 )   PDF (464KB) ( 878 )  
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    The basic principles and concepts of impedance matching are presented.Impedance matching is commonly used between the amplifiers at all levels,amplifier and load,signal and transmission circuit,and even between microwave circuit and system design.The fundamental reason is that mis-matching of voltage and current in the low-frequency circuit and electromagnetic wave in the high frequency circuit may lead to serious reflection and damage instruments and equipment.Impedance matching is the solution,which is discussed in this paper.

    Application of the LVDS Interface Based on FPGA
    CHEN Ying, GAO Shuang-Cheng
    . 2012, 25(1):  8. 
    Abstract ( 1321 )   PDF (1118KB) ( 969 )  
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    This paper introduces the technology of LVDS and analyzes the LVDS interface in the application of high speed data transmission system.The paper puts emphasis on the LVDS_TX module based on FPGA.Finally,the experiment of the LVDS_TX module in the application of DAC system further shows the advantages of LVDS interface.

    A Speech Endpoint Detection Algorithm Based on Dual-threshold Two Sentences
    LU Qing-Qi, BAI Yan-Yan
    . 2012, 25(1):  13. 
    Abstract ( 1504 )   PDF (628KB) ( 1371 )  
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    Endpoint detection of speech signal processing is a very important step,which directly affects the accuracy of the speed and results in voice signal processing.The research on endpoint detection,especially in noisy environments,has always been the hot spots in voice signal processing.Aiming at the front-end detection,which is made for the voice recognition system,this paper compares the use of short-term energy with the use of short-term average zero-crossing rate for endpoint detection.It achieves a double-threshold method of endpoint detection programming and simulation by Matlab.Simulation results show that an accuracy of as high as 93% for endpoint detection can be achieved.

    Research on Measuring Polarization of Radar Signals
    ZHAO Peng-Fei
    . 2012, 25(1):  16. 
    Abstract ( 1053 )   PDF (571KB) ( 1338 )  
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    Polarization information,like amplitude,phase,frequency,and wave shape,is an important parameter of radar signals.Different emitters correspond to specified polarization states.The measurement of polarization styles has great significance to the classification and identification of emitters.In this paper,the orthogonal polarization antenna method is introduced to measure the polarization of the EM wave.The method is simulated by Matlab programs.Simulation results demonstrate the correctness of the theoretical model and the algorithm.The advantages and disadvantages of the method are presented.

    Design of a New Type of Mining Vacuum Permanent Magnet Controller
    DANG Wei
    . 2012, 25(1):  20. 
    Abstract ( 1568 )   PDF (492KB) ( 906 )  
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    Aiming at the control need of various mining permanent magnetic vacuum circuit breakers,this study realizes the new intelligent mining vacuum permanent magnet controller based on CPLD.The full electronic circuit non-contact integrated software design is adopted.The switching power with wide-range input and constant-voltage and constant-current output is adopted as the power.The voltage and current are continuously adjustable and therefore reliable.The electronic switch comprised mainly of a transistor and an IGBT is used to control the break-brake power so that the output energy can be controlled and adjusted,and the safety of the mine and the reliability of the breaker can be ensured.

    Design of the Loom Warp Tension Controller
    HE Zuo-Hui, WEI Wen-Bin
    . 2012, 25(1):  23. 
    Abstract ( 1062 )   PDF (591KB) ( 1076 )  
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    This paper describes the design of the loom warp tension control system.We establish a mathematical model of the loom warp tension control system by analyzing the stress of the back beam of the loom-off system.Through the analytical method,we design the hardware of the current regulator,the speed regulator and the tension regulator and do programming experiments with the Matlab m file.The result shows that the system does not respond fast enough,but it is stable and reliable,and also facilitates the adjustment of the system.

    Design and Simulation of Boost-Switch-Power Based on PSpice
    TANG Wei-Bin
    . 2012, 25(1):  27. 
    Abstract ( 1739 )   PDF (677KB) ( 978 )  
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    The topology structure and simulation waves of the boost-switch-power are introduced and analyzed.The unsteady characteristic of the PWM circular mode is presented and its solution is given.A commonly used boost-switch-power with the UC2843 as it core is designed using the popular PSpice software.The circuit is easy to debug and it has the advantages of stable operation,high reliability and low cost.

    Design and Implementation of the Wireless Sensor Network Node
    WEI Ran
    . 2012, 25(1):  31. 
    Abstract ( 1536 )   PDF (866KB) ( 845 )  
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    A wireless sensor network node with light weight,small size,low energy consumption is designed.The node uses the MSP430 microcontroller as MCU,CC2420 as RF transceiver,FT232BM as conversion chip,and SHT11 temperature and humidity sensor.The other peripheral chips,power circuit and JTAG debugging interface are also included.Through JTAG debugging and the installation of TinyOS operating system,the date collection,wireless transmission and networking function are achieved effectively.

    The Statistical System for Scenic Area Tourist-flow Distribution Based on the Image Analysis Technology
    SONG Lei, CHEN Guo-Qiang, LIN Hong-Bo, TAN Ye-Gang
    . 2012, 25(1):  36. 
    Abstract ( 1137 )   PDF (953KB) ( 939 )  
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    As part of the construction of Digital-Taishan,this paper presents a method for collecting and analyzing the scenic spot tourist-flow distribution data accurately with Taishan scenic area as an example,which uses the image analysis and recognition technology for the outdoor complex environment.This paper also discusses the system deployment scheme and the methods for improving the recognition accuracy rate and solving the existing problems.Finally the paper sums up the method for analyzing the scenic area tourist-flow distribution based on the image analysis technology.

    Design of Image Transmission Between FPGA and DSP Based on EDMA
    ZHANG Yao-Qin, HANG Juan, WANG Yu-Fan
    . 2012, 25(1):  39. 
    Abstract ( 1074 )   PDF (521KB) ( 759 )  
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    This paper designs the hardware of image transmission between FPGA and DSP,and introduces the working principle,parameter configuration and transmission process of EDMA.The process is realized on an experiment platform.Finally the correctness and the stability of the process is verified through the restoration of the received image data into images by TI's CCS.

    Fuzzy Controller HDL Code Automatically Generated Based on Matlab
    ZHU Ge-Jun-Gui
    . 2012, 25(1):  42. 
    Abstract ( 1334 )   PDF (558KB) ( 991 )  
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    This article,taking the Water Level Control in a Tank as an example,proposes a fuzzy controller automatic HDL code generation method based on Matlab.The generated code can be ported to the FPGA control system.The method is divided into four steps:(1)The fuzzy controller is designed using Fuzzy Logic Toolbox in the Matlab.(2)The fuzzy controller is transformed into the form of Lookup Table.(3)The controller Lookup table is implemented with the state machine.(4)The fuzzy controller implementation with state machine was translated into HDL code by HDL Coder.

    Design of the Monitoring and Controlling System of Heating by Residual Heat in Blast Furnace Granulating Water
    XU Li-Li, ZHOU Yang-Min, LUO Si-Yi, LI Chao, YI Chui-Jie
    . 2012, 25(1):  45. 
    Abstract ( 1874 )   PDF (697KB) ( 877 )  
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    A constant temperature and variable flow control system is designed based on the fact that blast furnace slag is not continuous and granulating water temperature is largely fluctuated,including hardware and software.The data acquisition module in the hardware part uses Siemens S7-300 series PLC.The software part uses Wincc and Step7 to realize system configuration and data acquisition respectively.Experimental results show that the system has the characteristics of stable running and easy operation and maintenance.It can realize the function of real-time monitoring of residual heat in B.F.waste water.

    Augmented Filter Bank Common Spatial Pattern in Motor Imagery-based Brain-Computer Interface
    HOU Bing-Wen, LIU Peng, ZHOU Guang-Yu, HE Jia-Quan
    . 2012, 25(1):  48. 
    Abstract ( 1741 )   PDF (788KB) ( 892 )  
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    This paper proposes the augmented Filter Bank Common Spatial Pattern,a novel feature extraction algorithm for the motor imagery-based brain-computer interface.Compared with the Filter Bank Common Spatial Pattern,our method takes into full consideration the specificity temporal information,in which ERD happens in motor imagery.In this way,more features are acquired,and the higher accuracy and kappa value are obtained by these features.Two kinds of feature selection algorithms are employed in the BCI competition dataset.The results show that the accuracy based method yields superior classification accuracy compared with that based on mutual information.

    Implementation of the Embedded File System Based on VDK
    LIN Sen, CAO Xiao-Man, FANG Huo-Neng, XING Kai-Yu
    . 2012, 25(1):  53. 
    Abstract ( 1226 )   PDF (732KB) ( 802 )  
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    According to the high speed storage system based on the Nand Flash which has been developed by our laboratory,this paper states the specific realization of the embedded file system,which makes use of the BF537 and the kernel of the integrated development environment Visual DSP++ called VDK.It also introduces the process of virtual address mapping and bad block mark to manage the bad blocks of Nand Flash and realize the address transmission of the file system.

    Design of the Brushless DC Motor Control System Based on MC9S12X128
    MENG Qing-Bin, MA Bin, WANG Chang-Tao, BIAN Shu-Hai
    . 2012, 25(1):  56. 
    Abstract ( 1292 )   PDF (847KB) ( 973 )  
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    A brushless DC motor control system is designed in order to meet the requirements of high precision,speed performance and low cost.In this system the microcontroller MC9S12X128 is used as the control and disposal center,and the IR2130 chip is adopted to drive the MOSFET power transistor to achieve the three phase six step PWM control of the brushless DC motor.The system has the advantages of simple structure,easy speed adjustment and low power consumption.The practical application shows that the BLDC motor runs smoothly and reliably.

    A New Program of Long-distance Vehicle Monitoring Based on the OBD System
    NONG Wei, HOU Jun-Cheng, HU Rui-Nan
    . 2012, 25(1):  61. 
    Abstract ( 1256 )   PDF (858KB) ( 790 )  
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    With the aid of the concept of vehicle networking,this paper proposes a new automobile maintenance concept and its realization plan.The key point of this plan is using OBD and C/S network construction to collect vehicles information and form a backstage data system,which can realize vehicles information centralized management and provide better services for the vehicle owner by increasing the automobile manufacturer's profit.The paper discusses the frame,rationality,feasibility and the practical value of the plan,and gives both concrete technologies for its realization and the simulation,including the application of the OBD system in vehicles information collection.

    The Design of SDX-bus and Wishbone-Bus Interface Based on FPGA
    LIU Juan, ZHANG Zhi-Peng
    . 2012, 25(1):  65. 
    Abstract ( 1010 )   PDF (844KB) ( 949 )  
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    Aiming at the requirement of reliability,high data management efficiency as well as hardware cost of the airborne information acquisition system,this article mainly introduces the interface conversion of Sdx-bus and Wishbone-bus.The implementation of the design is based on Verilog HDL Language.It is simulated on the ModelSim software,synthesized on the Quartus platform and tested through FPGA from The Cyclone Ⅲ by Altera company.The results show that the design is feasible.

    The Project Design of the Inertia Integrated Navigation System
    WU Jun-Wei, LIANG Yan-Chao
    . 2012, 25(1):  69. 
    Abstract ( 1258 )   PDF (746KB) ( 816 )  
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    To meet the need of the integrated navigation computer's minimization and high performance so as to expand its applications,this paper designs an integrated navigation system based a PC104 and FPGA.The navigation computer system includes a data acquisition module and a data decoding module.The design for PC104 to transmit data to dual-port RAM in FPGA is proposed.In order to improve the data communication speed between FPGA and the industrial computer,a method for realizing data exchange through dual-port RAM is designed.The functions of and communication between modules are introduced from the aspects of the hardware structure and software design.

    Information Classification Approach with a Feedback Mechanism for Business Cards
    JIN Xin
    . 2012, 25(1):  73. 
    Abstract ( 978 )   PDF (549KB) ( 812 )  
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    Business cards play an important role in today's commercial affairs.Manual management is troublesome and error-prone,so research on automatic recognition and storage of business cards is of practical significance.This paper presents the working process of the traditional business card recognition system,analyzes the existing shortages,and then proposes a new information classification approach with a feedback mechanism for business cards.Layout analysis is considered as an important factor based on the traditional semantic concept,and the result of classification affects layout analysis in turn.By doing this,the system is rendered an increased recognition rate and is able to correct errors automatically.

    Interrupt Handling Based on ML507 Imbedded System Under VxWorks
    SHAN Yin, XIA Wei-Jie
    . 2012, 25(1):  76. 
    Abstract ( 1555 )   PDF (443KB) ( 834 )  
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    As the Powerpc processor is embedded in the virtex5 FPGAs by Xilinx Company,the adding of embedded operating system VxWorks makes it possible to create a more complicated embedded platform.The interrupt handling mechanism provided by VxWorks is of high performance in reducing latency,which is accorded with the real time requirement.In this paper,the interrupt handling mechanism based on Powerpc440 processor is analyzed.Then,the process of interrupt handling programming is described in detail.

    Three Dimensional Modeling Based on OpenGL and 3DS Max
    WANG Xin-Bo, ZHU Wei-Jie
    . 2012, 25(1):  79. 
    Abstract ( 1350 )   PDF (374KB) ( 869 )  
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    This paper describes how to use OpenGL technology and 3DS Max software to quickly build a three-dimensional scene.It also introduces the application of the 3DS model in the OpenGL application program.By lowering the difficulty with which the complex three-dimensional model is established by OpenGL,the workload of modeling is reduced.Through the use of the advantages of the professional modeling software 3DS Max,a more complex model is quickly established.And the OpenGL programming interface is used to protract the model in real time and control it interactively,thus reducing the modeling time and accelerating the system development process.

    The Architecture of the Medical Image Display System Based on Hanging Protocols
    LI Yong-Yi, ZHONG Xue-Li
    . 2012, 25(1):  81. 
    Abstract ( 1164 )   PDF (703KB) ( 801 )  
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    The software for displaying medical imaging requires complicated proofing and adjustment to read medical images,so it is difficult to be accepted by most doctors.The Medical image display system based on the architecture of hanging protocols is developed by Visual C++,VTK and DCMTK development tools.The medical software based on the hanging protocol architecture greatly simplifies the steps of a doctor's operation,and improves the efficiency in mining medical diagnostic information.

    Two Dimensional Shift-frequency Jamming on Curve Locus Missile-borne SAR
    LUO Yu-Heng
    . 2012, 25(1):  85. 
    Abstract ( 1073 )   PDF (834KB) ( 962 )  
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    Missile-borne SAR moves along curve locus.Its imaging algorithm is different from normal air-borne SAR.On the basis of the inherent coupling property between time delay and frequency shift of the pulse compression signal,this paper deduces the output form of shift-frequency jamming on missile-borne SAR based on the missile-borne squint SAR algorithm.The results show that orientation-dimensional displacement and the amount of frequency shift do not have a linear relationship,but to a lesser extent they approximate a linear relationship.Orientation-dimensional and range-dimensional shift-frequency can form two dimensional shift-frequency jamming when working at the same time,thus forming a flexible jamming pattern.Simulation verifies the correctness of the conclusions.

    Encoding Optimization of the JPEG2000 Image Compression Algorithm Based on Blackfin561
    DONG Zhi-Chao
    . 2012, 25(1):  90. 
    Abstract ( 1214 )   PDF (579KB) ( 798 )  
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    An optimization method of the encoding part of the JPEG2000 image compression algorithm based on a blackfin561 processor is presented,including some algorithm optimizations and a number of code optimizations such as loop unrolling,assembling of C program and assembly optimization.Time cost by the encoding module is greatly reduced and the real-time ability of encoding is obviously improved.

    Research on Broadwidth DRFM Adopting Chirp Transform
    LIU Lu
    . 2012, 25(1):  93. 
    Abstract ( 956 )   PDF (664KB) ( 769 )  
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    Broadband linear frequency modulation radar adopts Dechirp signals to reduce the bandwidth of the signal,and to obtain a huge processing gain of the broad bandwidth.Because of unmatched signal processing,it is difficult to realize the DRFM based jamming through narrowband processing.Illumed by Dechirp signal processing,this paper presents a broadband DRFM based on Chirp transform.The method can reconstruct radar signals through Dechirp transform,DRFM and Chirp transform.Theoretical analysis and simulation show that this method can reserve the time frequency characteristics and lower the processing bandwidth.

    Application of Location Information in Topic Detection
    XIE Lin-Yan, QI Yin-Cheng, SUN Zhuo
    . 2012, 25(1):  96. 
    Abstract ( 1126 )   PDF (506KB) ( 983 )  
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    Based on an analysis of a large number of Chinese reports,this paper proposes a topic detection algorithm to improve similarity.This algorithm is based on the Single-Pass clustering technique.According to the location information of the news reports,the content-based similarity and location-based similarity are measured and combined to realize topic detection.Experimental results indicate that the algorithm is superior to the traditional text similarity algorithm.

    Transformer Fault Diagnosis Based on the Artificial Immune Algorithm
    NIAN An-Jun, YUAN Jin-Sha, LI Zhong
    . 2012, 25(1):  99. 
    Abstract ( 1181 )   PDF (465KB) ( 891 )  
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    Aiming at the advantages and disadvantages of various transformer fault diagnosis methods,artificial immune,a new effective fault diagnosis method with its own unique characteristics,can be used to solve special problems and therefore provides a new thought to solve transformer fault diagnosis problems.Through Matlab experiment for standard data sets on the immune network,it is shown that this algorithm has higher classification accuracy.

    Optimization of PDN Impedance for the Multiobjective Evolutionary Algorithm Based on Decomposition
    ZHAO Zhi-Chao, ZHANG Shen, ZHANG Hui
    . 2012, 25(1):  101. 
    Abstract ( 1298 )   PDF (895KB) ( 864 )  
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    The frequent-domain design of a power distribution network (PDN) is a multi-objective problem (MOP).In this paper the multi-objective evolutionary algorithm (MOEA) is used to optimize power delivery network impedance,and the number and type of the decoupling capacitor become objective functions for optimization.This approach makes the input impedance of the PDN less than the target impedance within the cut-off frequency to meet design requirement.In order to solve this problem,the algorithm of MOEA/D is adopted in the simulation to optimize the two objectives simultaneously,and then we get the desired Pareto front (PF).Simulation results show that our design method is feasible for practical applications,has good stability and can achieve excellent results and that the Pareto Frontier we get meet the design requirement.Moreover,the number and type of the decoupling capacitor optimized is close to PF.

    Application Research of Web Page Purification Based on DOM and Neural Network
    LI Jian
    . 2012, 25(1):  105. 
    Abstract ( 1149 )   PDF (564KB) ( 782 )  
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    In order to remove the noisy information existing in web pages effectively,this paper proposes a method of web page purification based on the improved DOM tree and BP neural network.The establishment of a block tree by the DOM tree and web content using HTMLParser can split the whole content into several sub-block trees according to their relations,thus simplifying the processing of the whole block into the processing of sub blocks.Statistic data shows that the content of the sub block has evident numerical characteristics,so the sub block can be used as the learning source of BP.In this way,the purification of web pages is converted into establishing a purifying model through learning.Experimental results show that this method can achieve satisfactory results in the application to Chinese web pages with  themes.

    Simulation and Analysis of Temperature Modulate Curve in MOCVD with the Chipped Infrared Heating System
    HU Ying-Lu, LI Pei-Xian, LI Zhi-Ming, WU Li-Min, LIU Hong-Cai, LI Ding-Wei, BAI Jun-Chun
    . 2012, 25(1):  108. 
    Abstract ( 1665 )   PDF (659KB) ( 798 )  
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    The change of the peak point of the heating modulate curve,which is based on the modulation of the temperature,in the 2D numerical modeling for the MOCVD reactor is studied by the finite element method with the chipped infrared heating system as a research subject.According to calculation,the change of the modulate curve peak point has a close relationship to the material thermal properties of the Susceptor,the heating power,the geometric shapes and position of the heater in the chipped infrared heating system.The internal causes of peak shift are explained.In addition,three principles of designing the heating system are established:The larger the number of heaters is,the more flexible the system modulation is;the biggest power of the outer heater should be greater than the inner heater;the size of outermost heater should be small.The results are beneficial to the design of the MOCVD heating system and the optimization of the heating conditions.

    Design of Infrared Digital Image Displaying System Based on ADV7170
    WANG Yu-Fan, HANG Juan, ZHANG Yao-Qin
    . 2012, 25(1):  112. 
    Abstract ( 963 )   PDF (663KB) ( 833 )  
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    FPGA is used to control ADV7170 and receive digital images from the infrared thermal imager,which are converted into PAL analog signals and displayed by the television.The infrared digital image has the advantages of minimization,low power waste,and flexibility and therefore find wide applications in national defense technology.

    Overview of Laser-Based Optical Submarine Communication Channel
    ZHANG Wei, LIU Yang, XU Qiang
    . 2012, 25(1):  116. 
    Abstract ( 1284 )   PDF (524KB) ( 808 )  
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    The laser submarine communication system is able to send a signal through seawater to a great depth and transmit information at a rapid rate.It is important in the communication with a submerged vessel.The current domestic and foreign research on the laser submarine communication is presented.The research on laser transmitting properties in communication channel is proposed.The necessity of the research on the uplink channel of the submarine communication,especially in seawater-air interface's simulation,is shown.This study shows that communication system with the blue-green laser communication system as the core technology and the very low frequency (VLF) and extremely low frequency (ELF) system as the peripheral technology is the direction of the future laser submarine communication.

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