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      Volume 22, No. 3 | 2024
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      • CHEN Feng,LI Cong,ZHU Lidong,WU Qi,YUE Xiuquan,DAI Zhijian

        2024,22(3):227-239, DOI: 10.11805/TKYDA2023316

        Abstract:

        Satellite communication, as an important means of communication, plays a key role in modern society. However, with the development of communication technology, satellite communication system is also facing the increasingly serious interference problem and the challenge of interference recognition technology. In view of this situation, this paper first introduces the common patterns of satellite interference signals, and summarizes the development trends of satellite interference signals. Secondly, the research status of satellite interference signal classification and recognition technology is introduced from three aspects: feature extraction based interference recognition method, traditional machine learning method and deep learning method, and their respective advantages and disadvantages are analyzed. Finally, the future classification and recognition technology of satellite interference signal is prospected.

      • HE Junyan,LAI Haiguang,ZHAO Xinjie,LIU Ziwei,ZHANG Gengxin

        2024,22(3):240-248, DOI: 10.11805/TKYDA2023419

        Abstract:

        Satellite communication can provide over-the-horizon, large-capacity communication services. Nevertheless, there will be serious line-of-sight fading and significant multipath effect in urban areas, canyons, forests and other areas where the line of sight is seriously obscured, which will result in the degradation of network communication performance. Recently, an emerging technology―the Reconfigurable Intelligence Surface(RIS) is capable of dynamically altering wireless channels by flexibly controlling the electromagnetic properties of passive reflecting elements, providing a novel route for improving the quality of Low Earth Orbit(LEO) satellite communication. Based on the basic principles and advantages of RIS, the key technologies such as channel modeling, channel estimation, and beamforming in the RIS aided LEO satellite communication are discussed. Finally, the main challenges faced of RIS in practical applications are analyzed. This work can provide a reference for research in the field of RIS aided LEO satellite communication.

      • WANG Shuo,LI Chengjie,CUI Liqi,LI Cong,YUE Xiuquan,DAI Zhijian

        2024,22(3):249-260, DOI: 10.11805/TKYDA2023393

        Abstract:

        For addressing the issue of unauthorized actions bypassing security mechanisms to attack systems in the integrated network of heaven and earth in the open electromagnetic environments, an improved Genetic Algorithm(GA) is proposed. It uses the Decision Tree(DT) algorithm as the fitness function, and significantly improves the interception rate of network attacks by deleting redundant features in the dataset.Anomaly classification is performed through machine learning, and the feature selection function of the genetic algorithm is employed to enhance the classification efficiency of machine learning. To verify the effectiveness of the proposed algorithm, the UNSW_NB15 and UGRansome1819 datasets are selected for training and testing. Four machine learning classifiers, namely Random Forest(RF), Artificial Neural Network(ANN), K-Nearest Neighbor(KNN), and Support Vector Machine(SVM), are used for evaluation. The performance of the algorithm is evaluated through indicators such as accuracy, F1 score, recall rate, and confusion matrix. The experiment results prove that the genetic algorithm as a feature selection tool can significantly improve the classification accuracy and achieve significant improvement in algorithm performance. Meanwhile, to tackle with the instability of weak classifiers, this paper further proposes an ensemble learning optimization technique, which integrates weak classifiers and strong classifiers for optimization. The experiment confirms the excellent performance of this optimization algorithm in improving the stability of weak classifiers.

      • SHI Wenjun,ZHU Lidong

        2024,22(3):261-268, DOI: 10.11805/TKYDA2023439

        Abstract:

        In response to the problems of resource waste and long propagation time delay in traditional satellite power control methods, this paper proposes a satellite adaptive power control method based on Online Gate Recurrent Unit(Online-GRU) channel prediction, which solves the cumulative error of offline prediction algorithms by updating network parameters through online training. The simulation results show that the proposed online training algorithm improves the prediction accuracy by 38.30% compared to offline algorithms, saves 63.21% of training time compared to Online Long Short Term Memory(Online-LSTM), and saves 55.74% of transmission power compared to the fixed transmission power method. At the same time, the proposed adaptive power control method has better robustness compared to the adaptive power control method based on ground timing feedback channel state.

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      • GUO Mengze,FU Xuehan,ZHU Lidong,YAN Heyun

        2024,22(3):269-277, DOI: 10.11805/TKYDA2023440

        Abstract:

        In the ultra-high dynamic and low Signal-to-Noise Ratio(SNR) communication scenarios like deep space communication, traditional signal acquisition methods suffer from inadequate dynamic range support, insufficient accuracy, and the use of a narrowband Doppler model leading to poor approximation accuracy in the received signal. A wideband Doppler model is employed to model the received signal and a chirp signal is used for Doppler estimation and timing estimation. A sampling rate adjustment method based on binary-search is proposed for the receiver to overcome the mismatch between the Doppler-stretched signal and the local signal sampling rate. The simulation results of the synchronization performance show that the proposed method using Up-Down Linear Frequency Modulation(UD-LFM) signal is capable of achieving a Doppler estimation error below 400 Hz and a timing estimation error below 60 ns under a SNR of -49 dB and a maximum Doppler frequency of 2 MHz. Compared to direct acquiring, the proposed method bears a higher acquisition accuracy and a lower SNR threshold.

      • DUAN Xianglong,LIU Liu,ZHOU Tao,SU Zhaoyang,HAN Zijie,YIN Yi

        2024,22(3):278-284, DOI: 10.11805/TKYDA2024003

        Abstract:

        As an important supplement to the terrestrial network, the Low Earth Orbit(LEO) satellite network is an important part of the future earth-earth integrated network. However, due to the high moving speed of LEO satellites and the long propagation distance of satellite-ground communication, large propagation delay is caused, therefore a new calculation strategy for the Timing Advance(TA) of the uplink in the satellite-ground communication background of LEO satellites is needed. Based on the satellite-earth communication scenario of LEO satellite, TA and its provisions in the protocol are introduced firstly. Then, according to the characteristics of LEO satellite, a timing advance calculation method of LEO satellite communication is proposed. The effectiveness of the proposed scheme is verified by simulation analysis, which provides a reference for the design of satellite-earth communication system of LEO satellite.

      • ZHANG Wei,PENG Ziyang,MA Jingyu,HE Zhiyong

        2024,22(3):285-289, DOI: 10.11805/TKYDA2023249

        Abstract:

        Adaptive antenna array technology is the most effective method for anti-interference of Global Navigation Satellite Systems(GNSS). However, this anti-interference processing generates carrier phase measurement bias related to the direction of signal incidence, which limits the effective application in high-precision measurement. In order to reduce the bias of anti-interference processing, an analysis method of introducing measurement bias is proposed, a corresponding model is established, and a software receiver is built for simulation experiments. The results show that without adding additional constraints, adopting the space frequency minimum variance distortionless response algorithm to achieve a space frequency anti-interference processor would not introduce carrier phase measurement bias, making it very suitable for applications in fields with strict requirements on anti-interference performance and measurement accuracy.

      • SHENG Baicheng,SONG Xubo,GU Guodong,ZHANG Lisen,LIU Shuai,WAN Yue,WEI Bihua,LI Pengyu,HAO Xiaolin,LIANG Shixiong,FENG Zhihong

        2024,22(3):290-295, DOI: 10.11805/TKYDA2023168

        Abstract:

        A 260 GHz frequency tripler based on GaN Schottky barrier diode is proposed. Unbalanced structure is adopted with GaN SBD chip to improve the tolerable power and output power of the circuit. The height-reduced and width-reduced output waveguide structure is employed to suppress the second harmonic. The input and output filter of the frequency multiplier is designed with high and low impedance strip line structure. The test results show that the frequency multiplier achieves a maximum output power of 69.1 mW and conversion efficiency of 3.3% at 261 GHz with good harmonic suppression characteristics.

      • XU Limin,WU Heng,WANG Tao,CHENG Lianglun,QIN Yuwen

        2024,22(3):296-302, DOI: 10.11805/TKYDA2022164

        Abstract:

        Speed and accuracy must both be taken into consideration when using Terahertz Time-Domain Spectroscopy(THz-TDS) for security inspection of flammable and explosive contraband liquids in railway transportation. Due to speed limitation, the exact comparison of the precise fingerprint location between testing results and database, which is the common method adopted in laboratory analysis, cannot be directly utilized for the security inspection of large passenger flow. The reflective terahertz time-domain spectroscopy data for typical liquids in railway transportation is acquired under standard temperature, pressure, and normal humidity level(25 ℃, RH 60%). The categorized time-domain database for non-flammable and non-explosive liquids, flammable and explosive liquids, and strong acid, is established. Based on the database, the typical time-domain pulse patterns can be classified into four categories, namely terahertz time domain spectroscopy with obvious secondary pulse, minor secondary pulse, no secondary pulse and obvious negative secondary pulse. According to terahertz time domain characteristics, rapid detection with better than 80% of accuracy is achieved through classification decision model.

      • ZHOU Xinxing,TAI Xiao,LI Qi

        2024,22(3):303-308, DOI: 10.11805/TKYDA2021330

        Abstract:

        The Software Defined Radio(SDR) requires that the Digital to Analog Converter(DAC) must have higher and higher sampling rate, and the bandwidth of the transmitted signal is wider and wider. The traditional method of the Digital Up Conversion(DUC) cannot meet the application requirements because of the limited clock frequency of the Field Programmable Gate Array(FPGA). An optimized design method of high speed DUC is proposed to improve interpolation filtering and digital frequency synthesis. Firstly, the mathematical model of high speed DUC is deduced and the traditional DUC structure is optimized and improved. The implementation structure of the efficient and flexible interpolation filtering, as well as the structure of the multichannel parallel digital frequency synthesis are designed. Secondly, the coefficients of interpolation filters are given as well as the computing method of phase parameters for parallel digital frequency synthesis. The hardware implementation shows that the function of the optimized method is correct , and the method is convenient for engineering application. The data rate of the output digital Intermediate Frequency(IF)signal can reach 960 MS/s. The optimized method can realize the interpolation of different multiples, and can also produce high speed Local Oscillator(LO) signals with different rates. It can meet the requirements of DUC applications which need to transmit wide band and high rate signals in SDR.

      • LIN Zhao,WANG Xingcai,FENG Shijie

        2024,22(3):309-315, DOI: 10.11805/TKYDA2022037

        Abstract:

        When the signal is transmitted between systems with different modulation methods, the modulation format needs to be converted. Modulation format conversion is usually carried out on electrical signals and requires a process of electro-optical conversion after optical-electro conversion. Frequent optical-electro or electro-optical conversion usually increases the system cost. To address this problem, the implementation of format conversion from Binary Phase Shift Keying(BPSK) to Quadrature Phase Shift Keying(QPSK) and from QPSK to Quadrature Amplitude Modulation(16QAM) by using coherent superposition methods on the optical domain is proposed. In the experiment, the conversion model is simulated by Optisystem software, Taking 10 Gpbs pseudo-random signal as the test signal, it is successfully converted to QPSK and 16QAM observed by constellation diagrams. The Bit Error Rate(BER)of the conversion model and the direct QPSK and 16QAM transmission models are compared under different Optical Signal Noise Ratios(OSNRs), optical source bandwidths and signal powers. The BERs of the conversion model and the direct transmission remain highly consistent under the same conditions, indicating that this modulation format conversion method has high stability and accuracy, and can be applied to signal transmission between different systems.

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      • WANG Hairong,TANG Shenghua,XIAO Xin,DAI Jia,DING Xiaojin,ZHANG Gengxin

        2024,22(3):316-323, DOI: 10.11805/TKYDA2022004

        Abstract:

        The spectral occupancy model of satellite spectrum sensing data in the temporal dimension is analyzed. Because the bottom noises in satellite receiving data are undulated in different time and space, the traditional modeling methods with fixed threshold are defective. Therefore, the adaptive threshold method is introduced to determine the noise threshold and preprocess the satellite spectrum data to obtain the satellite spectrum occupancy length sequence. In order to make an effective statistical analysis on the situation of the satellite spectrum, the probability density curve of the spectral occupation time length series is fitted by using the Poisson and exponential distribution methods, and a probability distribution model suitable for the satellite spectrum occupation time series is obtained. Based on the obtained satellite spectral occupancy state model, the state transfer matrix at a certain frequency point of the satellite channel is calculated by two-state Markov chains to predict the probability of outgoing channel occupancy and idle. In addition, the Back-Propagation(BP) neural network is trained through the data set constructed by satellite spectrum sensing data to predict the occupancy length of a certain frequency point. By calculating the Root Mean Square Error(RMSE) of the BP neural network and the conventional Long Short-Term Memory(LSTM) neural network prediction methods, 0.172 8 and 2.208 1 are obtained respectively. The evaluation results show that the BP neural network bears the advantage of high accuracy.

      • QI Ziyang,CHEN Weiwei,RONG Fan,JI Yuhang,YAN Liping,ZHAO Xiang

        2024,22(3):324-330, DOI: 10.11805/TKYDA2023246

        Abstract:

        Due to the complex electromagnetic environment, Electromagnetic Compatibility(EMC) problems emerge, and the impact of interference on transmission lines can not be ignored. Based on the classical field-line coupling model―Agrawal model, this paper calculates the electromagnetic coupling effect of each field-line parameter of Twisted-Wire Pair(TWP) with Finite-Difference Time-Domain(FDTD), and gives guidance on the field-line configuration to reduce the disturbance. Finally, the influence of each parameter on the electromagnetic coupling effect of the interference source on the twisted pair is summarized: length will affect the frequency selection characteristic at the terminal load; the effect of pitch is small, and the shorter pitch will decrease the coupling; the height significantly affects the electromagnetic coupling, and the higher the height, the greater the coupling is; the incidence angle, azimuth and polarization angle all influence the electromagnetic coupling effect differently, and it can be seen from the tangential component of electric field's slice diagram that the analysis on one corner needs to take into account the influence of the other two corners. The electromagnetic coupling effect of TWP transmission line is closely related to the field line parameters, and each parameter shows different degrees of influence. Through the calculation of the model in this paper and the analysis on the results, an effective configuration of low-disturbed TWP transmission line can be obtained.

      • CHEN Xing,ZHANG Chao,LI Xiaolin,ZHAO Yongzhi

        2024,22(3):331-336, DOI: 10.11805/TKYDA2023208

        Abstract:

        A Ku-band dual-channel 3D integrated T/R module for array antenna system is designed and fabricated based on silicon Micro-Electro Mechanical System(MEMS) technology. The module consists of two layers of silicon-based packages stacked by Ball Grid Array(BGA). The upper and lower layers of silicon-based packages are realized by five layers of silicon wafers through Through-Silicon-Via(TSV) and wafer-level bonding. The module integrates the functions such as 6 bit digital control phase shifting, 6 bit digital control attenuation and serial-to-parallel conversion, negative voltage bias, power modulation. The finished module size is only 15 mm×8 mm×3.8 mm. The test results show that in the Ku-band, the saturation output power of the transmitting channel is greater than 24 dBm, the gain of transmitting channel reaches 20 dB, the gain of the receiving channel is greater than 20 dB, and the noise coefficient is less than 3.0 dB. The assembly bears the advantages of high performance, light weight, small volume, high machining precision and high assembly efficiency.

      • RAO Yunhua,HE Hao,WAN Xianrong,YI Jianxin

        2024,22(3):337-344, DOI: 10.11805/TKYDA2022046

        Abstract:

        The beamforming method of current Orthogonal Frequency Division Multiplexing(OFDM) passive radar cannot effectively distinguish the target signals distributed at the same angle and different distances. A new frequency diverse processing method based on subcarrier extraction of passive radar receiving signal is proposed. The beampattern can be turned into range-angle dependent by extracting and processing different subcarriers independently for each receiving channel, thus the targets distributed at the same angle and different distances can be processed differently. And the effect of parameters in frequency diverse processing is also investigated. The increased degree of freedom in range dimension with frequency diverse processing can help focus the beam energy on the desired point in space, which improves the performance of radar in target detection, location, and clutter suppression. Simulation analysis shows that a dot-shaped beampattern can be obtained with frequency diverse processing for OFDM passive radar receiving signals, and the experimental results also verify the effectiveness and the practicability of the proposed method.

      • SU Long,GU Shaohu,DENG Guiping

        2024,22(3):345-352, DOI: 10.11805/TKYDA2022033

        Abstract:

        A two-level Nested array is employed to construct a sparse L-shaped array. For this array, an angle estimation method based on compressed sensing is proposed. This method calculates the autocorrelation covariance matrix of the received data and quantizes it, and then reorders and removes the redundancy to obtain the incidence angle information of the virtual array. The length of the virtual array is much larger than that of the actual physical array, so compared with the uniform L-shaped array with the same physical array element, the array aperture and degree of freedom have been greatly improved. Finally, the orthogonal matching pursuit technique is adopted to solve the l1 norm constraint problem of the virtual array. Computer simulation shows that the proposed algorithm has higher source resolution and better estimation performance under the conditions of high signal-to-noise ratio, high snapshot number and large angle interval.

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      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

          2012,10(1):22-26, Doi:

          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.

        • WANG Yi,LIAO Xiao-ju,PAN Ze-you

          2011,9(1):7-11, Doi:

          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.

        • WANG Xiao-xia,CHEN Lian,LI Xin-yao

          2010,8(5):569-572, Doi:

          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.

        • XIAO Yong-jian,XIAO Li,SUN Zhi-gang

          2013,11(4):583-587, Doi:

          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.

        • JIANG Xiao-guo,YANG Xing-lin,LI Hong,WEN Long,SHI Jin-shui,ZHANG Kai-zhi,LI Jing,WANG Yuan

          2010,8(5):573-576, Doi:

          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.

        • WANG Bo,ZHANG Yan

          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.

        • 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.

        • JIANG Xiao-ping,LI Zhong-jie,YU Xiao-feng

          2010,8(4):451-454, Doi:

          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.

        • ZHANG Lidong,DAI Zuoxing

          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.

        • 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.

        • XU Ping,QING Lin-bo,HE Xiao-hai,YANG Chao,XU Guang-hui

          2010,8(1):67-70, Doi:

          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.

        • WANG Peng,YANG Chun,WEN Zhao-Jin

          2010,8(3):247-250, Doi:

          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.

        • MIAO Jiang-hong,MA Guo-ning,HE Yu-dong,YIN Liang

          2010,8(6):647-651, Doi:

          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.

        • HE Xiao-dong,DING Li

          2010,8(3):313-317, Doi:

          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.

        • ZHOU Xiao-qing,LI He-sheng,TAO Rong-hui,CAI Ying-wu

          2010,8(2):211-214, Doi:

          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.

        • 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.

        • 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.

        • 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.

        • 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.

        • 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.