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DU Jiayu,CHENG Haifeng,ZHU Xiang,GUO Fangjin,WANG Weibo
2023(11):1285-1294, DOI: 10.11805/TKYDA2022245
Abstract:
With the development of next-generation communications and equipment towards wider bandwidth and higher accuracy, millimeter wave and terahertz band has become the research focus of microwave technology. Transmit power is a significant figure of terahertz system, which directly determines the operating distance. Millimeter wave and terahertz solid-state power devices reveal great advances recently, and the engineering realization of terahertz solid-state power amplifiers at home and abroad is promoted. In this article, the international research status of millimeter wave terahertz power combining technology and solid-state power amplifier is introduced, and the latest research progresses of solid-state power amplifier modules based on radial combining, rectangular waveguide combining and silicon waveguide combining at W and G band in China, especially in Nanjing Electronic Devices Institute, are concluded.
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JIN Yuhuan,ZHU Fengxia,FENG Jianxin
2023(11):1295-1305, DOI: 10.11805/TKYDA2022237
Abstract:
With the wide application of high performance composites in aerospace, military and other high-tech fields, more and more attention has been paid to the quality and performance inspection of composites. How to conduct Nondestructive Testing(NDT) of composites by various methods has become a hot research direction for researchers in recent years. Terahertz wave has low quantum energy and is transparent to most non-polar substances, so it has unique application advantages in the field of nondestructive testing of composites. In this paper, based on the characteristics of THz technology, the nondestructive testing of Terahertz Time-Domain Spectroscopy(THz-TDS) and terahertz imaging technology are discussed in detail, and the current development trends of terahertz nondestructive testing technology for composite materials are summarized. Finally, the development prospect is outlooked.
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YANG Chen,XIE Shunqin,QIU Rui,LI Xianglu,XIE Nan
2023(11):1306-1317, DOI: 10.11805/TKYDA2021412
Abstract:
Aiming at the UAV air-ground channel, based on the Space-Alternating Generalized Expectation-maximization(SAGE), the channel characteristic parameters are estimated with high precision, and the small-scale fading characteristics of the air-ground channel such as multipath delay and multipath power are extracted. Then, using uniform quantization and non-uniform quantization methods, the wireless channel key quantization is carried out on the main path power and the main path-multipath power difference of the measured data. The quantification efficiency, randomness, and algorithm running time of the key are analyzed for takeoff and cruise scenarios respectively, and compared with the key quantification results based on large-scale features. The key quantization efficiency results show that the non-uniform guard quantization is superior to the uniform guard quantization; the quantization method based on high-precision estimation of channel characteristics is better than traditional quantization based on large-scale features; and the quantization in the take-off scenario is better than that in the cruise scenario. The results of the performance test show that the keys obtained in these quantizations have good randomness; the running time difference of different quantization methods is small, therefore, the two quantization methods based on high-precision extraction bear low complicity.
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Research and implementation of tracking demodulation algorithm for high dynamic and weak GNSS signal
WU Junwei,LIANG Taotao,WANG Chuan
2023(11):1318-1323, DOI: 10.11805/TKYDA2021322
Abstract:
In some high dynamic weak signal scenarios, the carrier phase is difficult to lock. In order to track the high dynamic weak Global Navigation Satellite System(GNSS) signal, considering that the Frequency Locked Loop(FLL) is more robust than the Phase-Locked Loop(PLL), an algorithm based on FLL+differential demodulation is proposed to track and demodulate the GNSS signal. The algorithm uses the second-order FLL to track the frequency of satellite signal, and the differential demodulation algorithm is employed to demodulate bit data. In engineering application, the algorithm adopts the architecture of Field Programmable Gate Array+Digital Signal Processing(FPGA+DSP), realizes the pre-processing of signal tracking signal in FPGA, and realizes the tracking loop algorithm, bit synchronization and differential modulation in DSP. The simulation of the algorithm is performed in Matlab platform, and the algorithm is verified by receiving the real GNSS signal from the simulator platform and the sky. The simulation and experimental results show that the algorithm can realize the stable tracking of satellite signal and data demodulation under the condition of high dynamic and weak signal, and overcome the problem that the data cannot be demodulated due to the difficulty of PLL locking, finally realize the Position Velocity and Time(PVT) solution of GNSS signal under this condition.
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ZHANG Hui,MA Sha,WAN Lei,SONG Sida
2023(11):1324-1332, DOI: 10.11805/TKYDA2021323
Abstract:
High range resolution of radar requires wideband transmitted signals, but the radar transmission of continuous wideband signal is limited by hardware cost and available spectrum resources. When multiple narrow-band signals are used for wideband aggregation, the range side-lobes will increase and the unambiguity range will decrease as the spectral discontinuity and step size of the narrowband signals increase. In order to solve the above problems, a new sparse frequency configuration is proposed, which can obtain equivalent continuous uniform stepped frequency signals through differential processing between sub-bands. Moreover, to make full use of the discontinuous sub-bands with large frequency span, the influence of frequency spans on target scattering characteristics is analyzed and a frequency consistency correction method based on Geometric Theory of Diffraction(GTD) model is proposed. The effects of different frequency spans on wideband aggregation are simulated and analyzed.The possibility of cross-band wideband aggregation is proved.The research of this paper can provide a reference for the backward compatibility of radar systems.
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GAO Jingxia,WANG Haitao,OUYANG Shan,LIAO Kefei
2023(11):1333-1341, DOI: 10.11805/TKYDA2021324
Abstract:
With the opening of low-altitude airspace and the development of aviation technologies such as drones, the detection of low-altitude targets in areas with tight electromagnetic spectrum such as cities or suburbs has become more and more important. 5G based passive bistatic radar has a wide application prospect in this field. Compared with 4G network, the implementation details of 5G waveform scheme have undergone essential changes. Therefore, the ambiguity functions based on the signals of different external radiators are also quite different. Nevertheless, there is still lack of research on the ambiguity function of 5G signal. Based on basic structure of signal, the differences between 5G signal and 4G signal in frame structure and physical resource structure are analyzed in detail in theory. System simulation model is built, and the radar ambiguity function based on 5G signal is simulated. Finally, the cause of the ambiguity and the possible influence on the signal detection performance are analyzed, and the suppression methods of some side peaks are briefly explained. This work provides a new idea and direction for the suppression of side peaks of external radiator radar based on 5G signal.
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JIANG Bingxuan,XIAO Wei,ZHANG Zhengping
2023(11):1342-1350, DOI: 10.11805/TKYDA2023126
Abstract:
This paper introduces and analyses a novel dielectric base plate with an asymmetric shape and dielectric property aiming to achieve a uniform temperature distribution over the heating sample. Firstly, the proposed dielectric base contains FR-4(FR-4 Epoxy Glass Cloth) and alumine and is located within a commercial microwave oven to heat a potato sample. The permittivity and geometric values of the base are the selected parameters to be optimized for the sake of lowering the Coefficient Of Variation(COV) of temperature on the spherical medium heating sample and improving heating uniformity. Secondly, calculation of the multiphysical field simulation is applied to simulate the heating process. The simulation results based on COMSOL Multiphysics show that the COV decreases from 0.9134 to 0.5446 with the dielectric base. In other words, the COV declines by over 40%. Finally, an experimental system is built to measure the temperature of the heating sample to validate the simulations and calculations. Good agreements have achieved between the simulation and experiment, showing good consistence in temperature rise curves. It illustrates that the novel dielectric base can make the temperature uniformity of the heating sample improved.
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XU Jian,XIAO Qiufeng,CHEN Yongqi
2023(11):1351-1356, DOI: 10.11805/TKYDA2022161
Abstract:
In order to make the high-frequency high-speed high-power transceiver component Transmitter and Receiver(T/R) work reliably and stably in complex electromagnetic environment, the design of component switching control, component power supply and ground, component layout and shielding are analyzed, the points of attention are suggested, and the design method is put forward. In the T/R component switching control design, the common mode interference problem is solved by a pair of delay and conjugate delay circuits to ensure that the transceiver time is longer than the driving switching time. The differential mode interference problem is solved by pulse width detection and maximum switching speed constraint. In the analysis of power supply and ground, the ground spacing is emphasized to not exceed one-twentieth of the signal wavelength. In the design of layout and shielding, the cavity resonance wavelength is analyzed in emphasis. Example modules are given and the above three design points are analyzed against each other to finally achieve stable and reliable operation in complex electromagnetic environments.
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ZHOU Xiaoya,SHI Dan,ZHANG Peng,MA Hongbing,ZHONG Zhigang,MA Jun,ZHANG Fangjian
2023(11):1357-1363, DOI: 10.11805/TKYDA2022226
Abstract:
The electromagnetic radiation prediction method of 5G base station is studied. A General Regression Neural Network(GRNN) model-based electromagnetic radiation environment representation method for base station is proposed, and the instantaneous broadband electric field strength at the ground plane of the theoretical maximum radiation point around the base station is predicted. 80% of the data is taken as the training set and 20% as the test set. Given the antenna transmission power, the distance between the 5G base station and its theoretical maximum radiant point, the data transmission time, the obtained Mean Absolute Percentage Error(MAPE) is 0.087 1, and the operating time is 3~5 min. The method shows good prediction accuracy and fast running speed. At the same time, by comparing with other models, the superiority of the method is verified, which is manifested in the substantial improvement of prediction accuracy and efficiency. With the increase of the prediction range around the base station, the advantages become more obvious, and the method has good applicability to different scenarios.
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CHEN Xi,MA Jianbo,LI Pengzhe,ZHANG Guifu
2023(11):1364-1369, DOI: 10.11805/TKYDA2022114
Abstract:
Aiming at the problem of low resolution of millimeter wave human security inspection equipment using three-dimensional synthetic aperture imaging technology, a wavenumber domain IAA imaging algorithm is proposed by combining Iterative Adaptive Approach(IAA) technology and synthetic aperture imaging technology. IAA technique can estimate the energy of the signal source corresponding to each potential position, and bears the advantages of high resolution, low sidelobe and is suitable for single snapshot estimation. Through theoretical model analysis and simulation operation, the reconstructed rendering is compared with the traditional matching filter rendering to verify the effectiveness of the algorithm. At the same time, with the improvement of computing power, the performance of the algorithm will also be improved.
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2023(11):1370-1380, DOI: 10.11805/TKYDA2021291
Abstract:
It is difficult for traditional intrusion detection systems to obtain the relationship among network attack behaviors. Taking an attack graph representation model as a guide, an intelligent mining model of attack events based on Bayesian network is proposed. A Bayesian attack association graph is established based on prior knowledge. The network attack behaviors are aggregated based on attribute similarity. An efficient Ex-Apriori algorithm is designed for network attack scenarios to discover the association rules among the attack behaviors, and the attack behavior group set is established. Finally, the attack behavior group set is calculated by using the parameters of the Bayesian attack association graph to realize the discovery of attack events. Experiments show that this model can effectively extract network attack events and discover attack paths, and provide theoretical and technical support for the discovery and countermeasures of network attack events.
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LI Chen,XIA Lidian,ZHANG Chao,YE Yangfeng
2023(11):1381-1386, DOI: 10.11805/TKYDA2023184
Abstract:
A load detection model based on Event Driven and Deep Learning(EDDL) is proposed to address the issue of low detection accuracy in current non-invasive load detection. The current data is detected through zero crossing, and the key events are discovered from a large amount of data based on event driven mechanisms. The end-to-end non-invasive load detection is achieved by converting the current sequence containing key events into image space and incorporating it into a deep learning based load detection model. The experimental results show that compared with the Multi-class Support Vector Machine(MSVM), Feedforward Neural Network(FNN), Convolution Neural Network(CNN), and Long Short Term Memory (LSTM) models, the proposed EDDL model has better overall performance, with detection accuracy and accuracy of 94.67% and 91.76%, respectively. The simulation results verify that the proposed model can mine current data based on event driven mechanisms and effectively extract current data features based on deep learning models, thus achieving high-precision non-invasive power load detection. This model has certain reference value for the research of non-invasive power load detection.
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WU Yingjie,LYU Xiumei,ZHANG Ziqiang,TU Cheng,ZHANG Xiaosheng
2023(11):1387-1396, DOI: 10.11805/TKYDA2022129
Abstract:
With the advent of the intelligent era, magnetic field sensors have been widely used in mobile devices to provide users with services such as positioning and navigation. At present, the magnetic field sensors based on Hall effect and the magnetoresistive magnetic field sensors which rely on magnetic materials are two dominant technologies in the market. The advantages of the magnetic field sensors based on the Hall effect include low cost, no need for magnetic materials and fabrication compatibility with the Complementary Metal Oxide Semiconductor(CMOS) technology. The operating range of this kind of sensors typically is from 10 μT to 1 T, and the resolution can be improved by increasing the power consumption. Magnetoresistive magnetic field sensors have high resolution and wide operating range(0.1 nT~1 T), and their performances mainly depend on the magnetic materials adopted. Besides these two technologies, resonant magnetic field sensors composed of silicon-based Micro-Electro-Mechanical System(MEMS) resonators have received extensive attention in recent years due to their benefits of small form factor, low power consumption, high performance and fabrication compatibility with CMOS technology. This paper reviews the latest developments of magnetic field sensors using silicon-based MEMS resonators. In addition, methods for improving the performance of such sensors are described. The current key challenges and future opportunities are provided.
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2023(11):1397-1402, DOI: 10.11805/TKYDA2021318
Abstract:
During the period that the Photoconductive Semiconductor Switches(PCSS) is operating at a high repetition frequency, it generates filament current heating, then the temperature of the PCSS quickly exceeds the maximum operating temperature, causing the PCSS to fail or damage. Combining the advantages of microchannel heat sink and jet cooling technology, a high-efficiency micro-channel/jet impingement heat sink is designed. Through experimental tests, the heat transfer characteristics of the micro-channel/jet impingement heat sink under different operating conditions are studied, and the heat dissipation performance is compared with that of the honeycomb micro-channel heat sink imported from the United States. The experimental results show that when the volume flow rate is 3 L/min, the heat transfer coefficient of the micro-channel/jet impingement heat sink exceeds 35 000 W/(K·m2), and the heat dissipation is as high as 1 000 W, which is higher than that of the honeycomb microchannel heat sink by 45%. Under the test flow rate, with the increase of the volume flow rate, the average heat transfer coefficient of the micro-channel/jet impingement heat sink approaches a linear increase. The average heat transfer coefficient of the honeycomb micro-channel radiator increases slowly at large flow rates. In addition, compared with the method that cooled by the honeycomb microchannel heat sink, the uniformity of the heat source temperature cooled by the micro-channel/jet impingement heat sink is significantly better, and it can reduce the temperature fluctuation of the heat source surface by 58%,which is more conducive to reduce the thermal stress of the PCSS.
The "In Press" section displays the articles officially accepted after peer review. These articles are currently under copyediting process without volume/issue information, but are citable according to their Digital Object Identifiers(DOI).
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LIN Jia-sen,LI Zhi,LI Qiao-feng,MA Yi-sen
Abstract:
Effective choice of the solution is essential to achieve a real-time, bi-directional(full- duplex) communication of the smart grid. The Power Line Carrier(PLC) technology provides a low-cost solution, which suits China's own national conditions. In this paper, the advantages of OFDM PLC modulation technology are introduced. A PLC module of system model is established through the analysis of the input impedance under the low-voltage power line channel. The high-speed PLC module based on low-voltage Power Line is also designed according to the studies of power line channel. The results show that the design of the PLC module has featured high receiving sensitivity and anti-noise ability.
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WANG Yi,LIAO Xiao-ju,PAN Ze-you
Abstract:
With the development of Internet applications, users’ demand for bandwidth is soaring sharply. Meanwhile,along with the development of broadband access technology, the endpoint can also adopt multiple network accesses. But due to one-way communication of traditional Transmission Control Protocol(TCP),the waste of resources will exist. To this end,IETF has specifically proposed Multi-Path TCP(MPTCP) to implement TCP multiplexing,thereby enhancing the efficiency and robustness. This paper gives a review of the IETF’s research on MPTCP,including MPTCP architecture, routing and congestion control, aiming to provide a reference for deeply studying.
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WANG Xiao-xia,CHEN Lian,LI Xin-yao
Abstract:
Traditional methods and instruments are not able to measure the true Root Mean Square(RMS) of distortion sine wave or non-sine signal accurately. This article introduces a method to measure the true RMS of any high frequency signal by using the true RMS measurement IC,AD536A,designed by AD corporation. The paper analyses the difference between the RMS measured by the average measure method and the true RMS in theory. It explains the disadvantages of current RMS measure method,and presents the design of true RMS measure circuit. The experiment results prove that the proposed method and circuit can measure the true RMS of any high frequency signal accurately.
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JIANG Xiao-guo,YANG Xing-lin,LI Hong,WEN Long,SHI Jin-shui,ZHANG Kai-zhi,LI Jing,WANG Yuan
Abstract:
The requirements for micro stress measurement of strain gauge are high precision,high linearity,high stability and high gain. One kind of differential amplifier circuit with excellent performance was designed. Some skillful techniques were adopted to avoid common voltage in the circuit and to reduce the temperature drift. The gain linearity is about 0.01%,and its Common-Mode Rejection Ratio(CMRR) is about 129 dB under work conditions.
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XIAO Yong-jian,XIAO Li,SUN Zhi-gang
Abstract:
Aiming at the problems in existing underground personnel positioning systems, an assisted positioning method based on pedestrian dead reckoning is proposed. Low-cost Inertial Measurement Unit(IMU) and magnetometer are employed to constitute a stable Attitude Heading Reference System (AHRS). The theory of inertial navigation is utilized, an algorithm for step detection is described, and Zero velocity Update(ZUPT) is adopted for velocity and position estimation to compose a pedestrian dead reckoning system. An experiment is performed in the corridor of a laboratory building to emulate the underground mine road environment. The experimental results demonstrate that the dead reckoning performs well and this method is an effective complement to existing underground positioning by improving the positioning accuracy.
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2015,13(1):1-12, Doi: 10.11805/TKYDA201501.0001
Abstract:
Terahertz(THz) optoelectronics has promoted the development of the THz generation, transparent control, and detection methods,and hastened many devices in the past decades. Especially, THz metamaterials and metasurfaces will exhibit extraordinary electromagnetic response when the subwavelength scale metal structure is excited by the THz illumination. Therefore, they have been applied to the devices such as wave beam shaper, waveguide, and modulator etc. The THz metamaterials and metasurfaces also show the potential applications in the research fields such as sensors, communications, and radars. In this paper, the works about the spectrum and wavefront modulation with THz metadevices carried out in our group are summarized. The basic theory and corresponding experiment results for different devices are introduced. It is expected these works can pave the avenue of the application of the THz metadevices.
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LI Mo,SUN Peng,SONG Yu,DAI Gang,ZHANG Jiana
2015,13(1):160-168, Doi: 10.11805/TKYDA201501.0160
Abstract:
According to the requirements of safe, simple and nondestructive radiation effect investigation of semiconductor devices, the method of laser simulation was proposed and greatly promoted. Compared with large-scale facilities, laser simulation has various unique advantages. It helps understand the ionization radiation effect in depth and is an effective low-cost, table-top supplement for the hardness assurance. Its research shows great significance for radiation effect study in both theory and practice. In this paper, the basic principles of the interactions of γ and laser with semiconductor devices are firstly presented. Then the physical basics and characteristics of laser simulation are given, with the research progress review followed. The existing problems of current research are deeply discussed providing with feasible research approaches. In the end, necessary research contents in the future are proposed.
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JIANG Xiao-ping,LI Zhong-jie,YU Xiao-feng
Abstract:
Radio Frequency IDentification(RFID) series Radio Frequency(RF) card has been applied widely because of its stability,reliability and easy operation features. Aiming at multiple protocols,such as ISO14443 protocol,ISO15693 protocol and Tag-it protocol,this study proposed a new type of circuit design based on Advanced RISC Machine(ARM) for the RFID series RF card reader. The data stream encryption was implemented by using peripheral device in the operation. The system composition,working principle and work flow were introduced. Then,the detailed circuit design of the RF network and encryption hardware were presented,and the test and analysis for the design were performed. The results showed that the circuit could accurately read, write and encrypt various types of card within effective range.
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2015,13(1):31-34, Doi: 10.11805/TKYDA201501.0031
Abstract:
The background requirements of the fuze antenna in terahertz spectrum as well as its advantages and disadvantages are introduced. The working principles and application characteristics of dielectric lens antenna in terahertz frequency are analyzed in order to implement the terahertz fuze antenna. The longitudinal size of H plane horn antenna can be reduced effectively by using fuze antenna formed by an H plane horn with dielectric lens antenna. The terahertz fuze antenna with different beam angles is achieved by focal technology of lens. The feasibility of the technology solution is verified through simulation.
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ZHOU Tian,YUE Yantao,XU Guanxiong,ZHANG Yangyang,JI Chunlin
2015,13(1):76-79, Doi: 10.11805/TKYDA201501.0076
Abstract:
Ultra-wideband(UWB) communication shows its advantages of fast data transfer(100 Mb/s or above) in a relatively short distance(typically below 10 m) with relatively weak power consumption (energy spectrum below -41.3 dBm/MHz). Integrated with Multiple Input Multiple Output(MIMO) technology, channel capacity could be further enhanced. As a critical link in the ultrawideband communication,UWB antenna needs extra efforts in design optimization to boost the performance of the whole system. UWB antenna is defined as the antenna whose bandwidth exceeds 500 MHz or relative bandwidth greater than 20%. This paper takes the most representative Vivaldi antenna as a show case for multi-objective optimization design with statistical methods. The optimized miniaturized antenna(sized130 mm×100 mm) shows a -10 dB bandwidth of 2.4 GHz. The design method provides guidance in common wideband,multi-parameter antenna design.
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Abstract:
High-speed data acquisition system is an important component in modern radar signal processing. A design of high-speed data acquisition system based on band-pass sampling was presented and applied to the signal processing of wideband receiver. The Virtex Series FPGA was used as the main platform to control the high-speed ADC08D1000 for completing data acquisition, transmission,storage and signal processing. High-speed First Input First Output(FIFOs) were selected as the storage devices to implement data rate conversion. The system realized the software and hardware design,and test results verified the feasibility of the solution.
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XU Ping,QING Lin-bo,HE Xiao-hai,YANG Chao,XU Guang-hui
Abstract:
The implementation of TCP/IP protocol stack on TM320DM642 platform could provide technological support for the application of multimedia embedded systems to networks. Both the function of TM320DM642 chip and the hierarchical structure of LWIP(Light Weight Internet Protocol) were analyzed. Network communications for TM320DM642 systems were implemented by the transplantation of LWIP, not by a solution scheme of NDK(Network Developer’s Kit). Testing examples verified the effectiveness of the LWIP transplanted method.
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WANG Peng,YANG Chun,WEN Zhao-Jin
Abstract:
This article introduces a new type of high speed,multi-modulated digital modulator with adjustable center frequency and bit rate features. It can realize the Quadrature Phase Shift Keying(QPSK) and 16QAM(Quadrature Amplitude Modulation) with 80 MHz center frequency and 7.936 5 MHz bandwidth. The general-purpose modulation arithmetic based on software radio,symbol mapping and the realization of pulse shaping filter are discussed. The measuring results demonstrate that the modulation scheme meets the requirements of practicability and general utilization.
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MIAO Jiang-hong,MA Guo-ning,HE Yu-dong,YIN Liang
Abstract:
The design of code tracking loop is a key sector of the realization of noncoherent spectrum spread receiver. In order to realize the code tracking in noncoherent spectrum spread receiver, an energy-normalization digital delay-locked loop was designed, the structure of the loop and the calculating procedure of loop parameters were introduced. The characteristic of noncoherent spectrum spread was analyzed first,and then the key point of the loop design was pointed out. Based on this, the design and realization methods of code loop discriminator, loop filter, early and lag code generator were expatiated. A set of specific loop parameters were introduced as well. Modelsim simulation results and FPGA actual measured data prove the precise code tracking ability of the design.
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JIA Zhuo,LIU Hao,DENG Yifeng,DENG Hong
2015,13(1):174-178, Doi: 10.11805/TKYDA201501.0174
Abstract:
The Spatial Light Modulation(SLM) technology has been widely applied to the fields of threshold switch, high speed optical interconnection and optical logic operations, which demands good performance on the real-time and fast optical signal addressing. Compared with Electro-Addressing SLM(EA-SLM), Optically-Addressing SLM(OA-SLM) shows great advantages of fast speed and high resolution by parallel addressing. Nevertheless, how to achieve fast and stable optically addressing is the key point in practice. Based on ZnO thin film as a photoconductive layer, Liquid Crystal OASLM(LC-OASLM) is designed and fabricated; the modulation of the readout light intensity and phase distribution in the two-dimensional space is achieved effectively.
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ZHOU Xiao-qing,LI He-sheng,TAO Rong-hui,CAI Ying-wu
Abstract:
The application of CORDIC(COordinate Rotation DIgital Computing) arithmetic in solving transcendental function has become popular in modern engineering. A brief introduction of CORDIC arithmetic was given in this study. Taking the hyperbolic sine and cosine functions as examples, the method of realizing the arithmetic in FPGA was presented and simulated on ISE(Integrated Software Environment) platform. The result showed this arithmetic was of good precision and instantaneity because of using pipeline. This arithmetic has great practical value in some applications. In addition, a curve of the relationship between the iterative number and the error obtained by the Matlab simulation of the arithmetic can help designers planning the number of iterations for practical applications.
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ZOU Xiang,QIN Linbo,HE Xiaohai,ZHANG Yuqiang,XU Shunfei
2015,13(1):111-117, Doi: 10.11805/TKYDA201501.0111
Abstract:
The corresponding solutions are proposed to tackle with the disadvantages of conventional oilfield Geographic Information System(GIS), including inconvenience of Client/Server(C/S) mode operation and maintenance, being unable to perform real-time online Point of Interest(POI) rendering, being incapable of segmentation and location according to regions, etc. An oilfield information query system of Browser/Serve(B/S) framework based on AJAX+JSON+HTML5 is designed and implemented. Experimental results show that the POI real-time rendering and regional segmentation improve on their interactivities, and the experiences of users are enriched, which meets the actual requirements of oilfield development. This work has paved the way for the development of diversified network services.
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XU Lei,TU Xuecou,WAN Chao,PEI Yufeng,KANG Lin,WU Peiheng
2015,13(1):27-30, Doi: 10.11805/TKYDA201501.0027
Abstract:
A detector can achieve quick response when it is much smaller than the wavelength of the source signal in THz wave band at the expense of signal coupling capability.Therefore, an antenna is applied to collect signals in order to enhance the signal coupling capability of the detector.The properties of antenna determine the frequency response band,the sensitivity and other parameters of the detector directly. A planar-integrated antenna is adopted for signal acquisition in the Nb5N6 microbolometer detector, which is fabricated by lithography,lift-off and other processes of micro-fabrication. The Nb5N6 microbolometer is placed in the center of the planar antenna. Aiming for the center frequency of 0.32 THz, a special capacitive coupling design is proposed to improve the signal coupling capability.
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LUO Ya,LIAO Qingmin,WANG Desheng
2015,13(1):35-39, Doi: 10.11805/TKYDA201501.0035
Abstract:
A double gate setting with priority of Doppler velocity and the Extended Kalman Filter(EKF) based Multiple Hypothesis Tracking(MHT) algorithm are proposed in order to realize Multiple Targets Tracking(MTT) in High Frequency(HF) ground-wave radar, and to effectively improve the performance of MTT by using the Doppler measurement. In the EKF based MHT, parameters obtained in the EKF are adopted directly to calculate the probability of each hypothesis. A simulation scene is built, and the EKF based MHT algorithm is compared with the one which assumes that the Doppler measurement is independent from the radius measurement. Simulation results show that the double gate setting helps induce number of clutter, and the EKF-based MHT algorithm is better than the other one under dense environments of HF ground-wave radar with stronger track-catching and false-alarm-filtering ability and higher efficiency.
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ZHANG Hao,YANG Yuhong,XIN Gang,DU Sen
2015,13(1):142-147, Doi: 10.11805/TKYDA201501.0142
Abstract:
The single-channel blind separation of GMSK(Gaussian Minimum Shift Keying) mixing signals is researched. The GMSK mixing signals can not be separated by the Per-Survivor Processing (PSP) algorithm directly, therefore, linear approximation processing of the GMSK signal is considered, which enables GMSK signal to be separated by the PSP algorithm. This algorithm separates the GMSK mixing signals by maximum likelihood estimation in the joint space of the symbol sequential and the channel parameters, reserves the best path and outputs the symbol pairs to get the separated signals. Simulation results show that the bit error rate performance produced by the PSP algorithm on separating the GMSK mixing signals is slightly better than that produced by the particle filtering algorithm; and the complexity of the proposed PSP algorithm is much smaller.
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WANG Liang-hong1,WANG Jin-ling2,LIANG Yan-hua1
Abstract:
A new usage of Hough Transform is introduced in this paper.Firstly,the position and scope of the license plate is located and the image that contains the license plate is picked up.Then, a two-stage Hough transform algorithm is applied to the image to cal
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Abstract:
A forward secure strong proxy signature scheme is proposed on the basis of the proxy signature schemes and forward secure schemes.The security of the proposed scheme relies on the difficulty of solving discrete logarithm problems and the difficulty of com
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Abstract:
Wavelet denoising is an important application of wavelet analysis in engineering.The keys of wavelet denoising,namely how to select threshold and how to utilize the threshold to dispose wavelet coefficients,are introduced.Via the noised simulated signal e
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Abstract:
Based on three generally accepted basic hypotheses, the definition of environmental factor and restricting conditions of constant failure mechanism are discussed.The research status and common study methods of environmental factor are reviewed. Finally, a
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QU Xin-fen1,2,SHANG Shun-chang1,YANG Qing1
Abstract:
For completing the scheme of hard target smart fuze, several factors influencing the outputting acceleration of the high-G accelerometer such as target material, impact angle, impact velocity, the fixed position of accelerometer, carry plane etc., are put