最新刊期
卷 ， 期 12 ， 1999
- 摘要：A smart antenna bed on equal side-lobe Pencil patterns was proposed in this Paper. For comparing withsmart antennas which employ adaptive algorithm, the capacity enhancement of both smart antennas in CDMA system is evaluated. The simulation result show that the adaptive algorithm das not have to be employed. Smart antennas with equal sidelobe pencil patterns has almost the same capacity enhancement Performance. Merits of equal side-lobe pencil Pattern smart antennas are without iteration, faster response and better robustnase.关键词：smart antenna;circular array;CDMA3|153|11更新时间：2025-12-08
- 摘要：Since the LFM signal occupies a wide band in frequency domain, it’s impossible to use singular value decomposition to separate the noisy LFM signal into signal subspace and noise subspace. To counter this drawback, a new subspacedecomposition algorithm based on the rotation of time-frequency plane is presented in this paper along with its correspondingperformance. A new concept, namely, the "pseudo signal subspace", and a new transform for detecting the tilting angle calledRadon-STFT transform are proposed. Theoretical predictions and simulation results indicate that the strategies advasted arefeasible for denoising a class of LFM signals.关键词：singular value decomposition;pseudo signal subspace;time-frequency distribution;Radon-STFT transform;rotation of time-frequency plane2|286|11更新时间：2025-12-08
- 摘要：In this paper, we present a methed for automatic path finding in active navigation of volumetric image databy using density profile image, and for active navigation of the tunnel-like structure in the medical volurnetric image data. Themethed uses directly the volumetric data information,so it can achieve a high speed in processing. Some experirnents on realpatient data show that this method is computationally efficient and allows a real-time local path determination.关键词：active navigation;density profile image;centerline determination;volumetric image data;matched filtering2|44|1更新时间：2025-12-08
- 摘要：Based on the layered-media wave theory and Graphical Electromagnetics Thoory, a methed of analyzing andcalculating the Radar Cross Section （RCS） 0f aircraft cockpit targets is presented and verified. The cabinsur face scatteringfields are obtained by using Graphical Electromgnetic Computation （GRECTh）, including cabin wedge scattering fields computed by ILDC methed. The reflectance coefficient and the traonsmittance mefficient are obtained by using the layered-mediawave theory. Then amplitude and phase weighing methed, called Energy Medulation and Random Phase Weighting methed,are used for calculating the structural scattering fields caused by the obects in the cabin. Numerical results fOr aircraft cabinsare provided at the end of this paper.关键词：layered-media system;graphical electromagnetic computing （GRECO）;C-R geometrical spline;phaseweighting method;energy modulation method2|86|1更新时间：2025-12-08
- 摘要：Based on PO & EMC methods the EM scattering characterization of bistatic RCS for facets and wedges ofcomplex targets is presented in this paper. IN WINDOWS NT/98 platform, the bistatic Graphical Electromagnetic Computingmethod is presented by using the Open Graphical Library and synthesis of the facets and wedges. The mathematical model andpractical example are given to verify the validity of the method. At the same time, it gives bistatic RCS curves of a complextarget for a practical case in virtual reality environment. The results have practical engineering value.关键词：electromagnetic wave scattering;radar cross section （RCS）;bistatic GRECO3|182|4更新时间：2025-12-08
- 摘要：Based on the principle of microwave imaging of the rotating targets,an INlSAR （ISAR Interferometry） 3-Dimaging technique of rotating targets is daseribed in this paper. The vertical position of scattering centers are given by comparing their phase difference fo two phase coherent 2-D images which are obtained by using two antennas with a little change in pitch angle. The doWn-range and cmerange opition and amPlitude of anttering centers of the 3-D irnage are given by one 2-D image .The The simulated and measured results are all satisfactory.关键词：radar targets;microwave imaging;measurement2|237|3更新时间：2025-12-08
- 摘要：How to suppress the burst interference in HF（High Frequency） radar, caussed by lightning and short wavecommunication, is an unsolved problem in the world. This paper for the first time reveals the singularity characteristic of burstinterference showed in Deppler domain. According to this charcteristic, an approach to detect the burst interference inDoppler domain using wavelet analyzing is presented and a scheme to depress the interference is given. Experiments 0f highfrequency radar prove that this method is effective. This paper theoretically solves the problem of how to detect burst interference in narrow band system, and successively suppress this sort of interference in HF radar; thus enhances HF radar s surviving ability.关键词：HF radar;Doppler signal;wavelet transform2|272|12更新时间：2025-12-08
- 摘要：This paper is presented to resolve the moving infrared target detection problem under the condition of lowSNR. The scheme of multi-frame accumulation is often adopted in low SNR infrared target detection, but for moving low SNRtarget, this simple accumulation scheme maybe degrades greatly. In this paper, a detectlon algorithm based on morphologicaldilation before accumulation and tracking before detection is prond. The dilation operation enables the energy 0f the sametarget in different frames can be accumulated effectively in spite of the movement of target, thus we can reach the aim of enhancing the target. A preprocessing algorithm using wavelet transform is also adopted to remove the correlation of l/f noise inparalle1 scanned infrared image. The whole algorithm is well analyzed and simulated with infrared image apuence. A high performance is reached and the experimental result indicates that the algorithm can effectively detect the moving target withSNR = 2.关键词：红外图像处理;红外目标检测;小波变换2|391|16更新时间：2025-12-08
- 摘要：Based on the theory of the estimation and fuzzy logical system, this paper proposes a data association algorithm of the fuzzy logic-probability interacting, to solve the data association problems typically encountered in the applicationof multisensor in tracking a maneuvering target in a heavily-cluttered environment. The combination of fuzzy association degree and probabilistic association forms the weights that the ith received measurment is target originated. The proposed dataassociation algorithm counteracts the weaknesses of probabilistic data association filter （PDAF）, and improves the performances of tracking a maneuvering target in a heavily-cluttered enviroment.关键词：模糊逻辑──概率交互作用;数据关联;密集杂波环境;机动目标跟踪;多传感器数据融合2|164|6更新时间：2025-12-08
- 摘要：When the a priori prohabilities and imt functions are fuzzy, the optimal decision fusion in the sense 0f minimum Bayesian risk at the fusion center is considered. The fusion center receives decisions from various distributed sensors andfour optimal decision fusion schemes at the fusion center are derived. It is discovered that the optimal decision fusion rule is aweighted sum of local decisions in this case, the weights are functions of the prohability of detection and the probaility of falsealarm of the detector, and that the threshold depends not noly on the fuzzy a priori probabilities and cost functions but also onthe criterion used for defuzzfying fuzzy sets. Through the simulation, an optimal decision fusion scheme which is most suitablefor fuzzy a priori probabilities and cost functions with trapezoidal membership functions is found.关键词：decision;fusion;fuzzy priori probabilities;fuzzy cost functions;Bayesian risk criterion3|509|3更新时间：2025-12-08
- 摘要：The analysis of Rotman lens, an important multiple beamforming network is accmplished by the contour integral equation method along with the planar waveguide medol method. First, the planar waveguide models for Roman lensand its feed lines which incorporate the dispersion effect with frequencies are set up. Then the aperture electric fields at lensports are expanded by appropriate waveguide mode functions and substituted into the contour integral equation. The multimode scattering rnatrix of the lens can be acquired by solving the cont0ur integral equation by using Galerkin method. To obtain the scattering matrix corresponding to the dominant mode, higher order modes aroused at lens ports are treated as loads ofthe network. It is proved that the calculated results are in good agreement with the experimental ones.关键词：multiple beam forming network;Rotman lens;planar waveguide model method;contour integral equationmethod2|163|8更新时间：2025-12-08
- 摘要：In FDTD-Diakoptics , a complex microwve circuit is partitioned into several simple sub-circuits. Each subcircuit is analyzed by finite-difference time-domin （FDTD） method independently,and a parallcl algorithm is applied to cascade all the sub-circuits together. The metdod in this paper is Particularly suitable to the analysis and design of the geometrically complex structures and the clectrically large circuits. With the sarne computational precision, the efficiency is improvedapproximately five times by using the proha apprcach compared to the method using are to analyze the circuit entirely.Therefore the method prasented in this paper is very useful.关键词：time-domain Diakoptics;finite-difference time-domain （FDTD）;Diakoptics;microwave circuits2|120|1更新时间：2025-12-08
- 摘要：The Segmentation and detection of will target image for infrared homing guidance head are crucial technolyies for ground-air and surface-air missiles. This paper studies the effect and performance coparison of suppnaing largearea and low frequency background by use of six high-pass filters. Based on this, we propose an adaptive threshold method ofbackground supprasion and small target segmentation using image mean and histogram. In view of the continuity and regularity of motion for target and the randomnere for noise, the design of continuity filter and a technique via assembly line andpipeline scheme to detect target trajectory are considered. The methods rourched here are verified by a large number of resultS of experiments and comparisons.关键词：infrared image;background suppression;high-pass filtering;adaptive threshold;target Segmentation;Target Detection3|1711|90更新时间：2025-12-08
- 摘要：This paper addresses the problem of identification of almost periodic time-varying moving average （APTVMA） systems using cyclic statistics. The nomal equation approches based on odd order time-varying cumulants are presentedfor parameters estimation. Model order detemination procedures based on time-varying and cyclic cumulants are also derived.Simulations are performed to illustrate performance of the presented methods.关键词：cyclic statistics;almost periodic time-varying MA system;normal equation;identification of system2|61|1更新时间：2025-12-08
- 摘要：The FMCW is introduced into short range TR-R2 multistatic radar system and an analysis is given, for locating the geometric center of a thin cylindrical target in short range using the high resolution of the wideband FMCW signal. Amethod and its analytical expressions for calculating the length of the target using echo spectrum are prasented. Taret velocity measeurement is of important significance for target detection and analysis, especially for reconnizing a target in shart range.In this paper, an algorithm for measuring target velocity with TR-R2 system is analyzed for the first time, and formulae for thecalculation of velocity are shown. System performances are discssed and simulated with the present algorithm.关键词：多基地雷达;调频连续波;系统分析2|99|5更新时间：2025-12-08
- 摘要：A new approach to on-line adaptive estimation of time-varying time delay is proposed. First, a modifiedstrong tracking filter algorithm is prasented,and an estimation model for the time-varying time delay is set up. Based on thismodel , the time-varying time delay can be directly estimated by the modified strong tracking filter algorithm. The proposedappoach is characterized by easy implementation, rapid tracking, high accuracy and etc. Finally, simulated experimental resultsare provided to show the effectiveness of the proposed approach.关键词：time-varying;time delay;adaptive estimation;on-line2|236|5更新时间：2025-12-08
- 摘要：A cled-form array response estimation （CARE） technique for blind source separation in wireles communication is developed by exploiting the data structure of second-order statistics of the array output in the presence of multipath.The proposed method achieves array response estimation with little constraint on signal property and propagtion environmentsuch as scatters or angular spread. Moreover, the array considered here can be of arbitrary geometry and even uncalibrated.关键词：antenna array;blind estimation;smart antenna;SDMA2|83|1更新时间：2025-12-08
- 摘要：In this paper, the singularity in the integrand of electrical field integral equation （EFIE） for 3-dimensionalvector fields scattering is first analyzed. Two numerical metods for solving the singularity integral equation are developed.One method is the singularity transferring method for calculating integral value containing O（1/R） singularity in its integrand[1];. The other singularity is removed first and the integral contribution of this small area is proved to be zero. Thus, theintegral on the whole integral area can be calculated properly by using numberical method.关键词：3 dimension vector fields scattering;electrical field integral equation;self-impedance;principal integral2|327|2更新时间：2025-12-08
- 摘要：Fuzzy clustering is an important branch of unsupervised classification, and has been widely used in patternrecognition and image processing. However, most of exiting fuzzy clustering algorithms are sensitive to initialization, andstrongly depend on the number of clusters, which limits their applications. Moreover , it also needs to know the type and number of prototypes in advance in multi-type prototype fuzzy clustering. To overcome these limitation, a metthod for acquiring apriori knowledge about clustering prototype is proposed in this paper,which obtains better performance in initializing multitype prototype fuzzy clustering.关键词：fuzzy clustering;mathematical morphology;thinning;curve fitting6|314|3更新时间：2025-12-08
- 摘要：This paper studies the application of smart antennas to the downlink in the FDD-CDMA. We estimate thedownlink channel covariance matrix and the relative interference to users of the other cells by using the uplink data., and present a method for downlink beamforming , i. e., we obtain the minimum relative interference to other users while the constanttransmitting power is guaranteed. The computer simulations show that this method has lower outage probility than themethod of only assuring maximum array gain in direction of the use.关键词：FDD-CDMA;downlink beamforming;channel covariance matrix;minimum relative interference2|91|9更新时间：2025-12-08
- 摘要：This paper proposes a novel long-term coherent intoption method for detection of weak high order polynomial phase signal （PPS）, such as weak echo signals from maneuvering targets in radar and sonar applications. The method exploits the time-frequency tiling property of adaptive wavelet transform （AWT）,and is practically realzable. In this paper, theunitary and linear phase wavelet basis function together with one order local linear approaching procedure are paesented to estimate the signal trace in time-frequency plane. Additionally, the Redon-Wigner transform （RWT） is exploited in subbandoutputs of AWT to achieve low computational complexity implementation. Analysis and simulation results confirm the efficacyof the method.关键词：weak signal detection;long-term coherent integration;AWT detector2|254|7更新时间：2025-12-08
- 摘要：The recently proposed super resolution radar imaging algorithms, which are based on the 2-D sinusoid signalmodel,often suffer from the motion through resolution cell error（MTRC） and failed completely. In this paper,an algorithm isproposed based on the 2-D approximate radar imaging model. By minimizing a nonlinear least-squares cost function, the algorithm combines the parameter estimation with the compensation of MTRC errors . The Cramer-Rao bounds are derived andsimulation results are also presented to demonstrate the performance of the algorithm.关键词：motion through resolution cell error;compensation;super resolution;radar imaging2|276|3更新时间：2025-12-08
- 摘要：The application background, research area, key technique problems and their resolution of ultra-high-speedradar digital signal processing were discussed. An ultra-high-speed data acquisition system, a high-speed digital pulse compression system, and an ultra-high-speed echo simulator were realized.关键词：radar;ultra-high-speed;digital signal processing;data acquisition;pulse compression;signal generator;signal simulator3|645|1更新时间：2025-12-08
- 摘要：It is pointed out that the land clutter, when the radar grazing ange is low, will cause the time spread 0f radarecho signal, For the pseudo-random code continuous wave （PRG-CW） radar, the echo signal at a specified moment will be thesuperpostion of some spread echo signals in a period of time before this specified moment. A superposition algorithm was proposed to calculated the PRC-CW radar signal. Based on the former results on the characterstics of land clutter, and consideringtemporal and spatial correlation charateristics between defferent resolution cells, the temporal correlation characteristics of theecho signal of land clutter for the PRG-CW radar are investigaed with simulation method. The results indicate that the echosignal of land clutter for PRG-CW radar is more corrlated than that for pulse radar.关键词：PRC-CW radar;land clutter;correlation characteristics2|139|1更新时间：2025-12-08
- 摘要：The selection of the transform matrix has an effect on the output signal to interference plus noise ratio. Itcan achieve its upper bound when transform matrix is selected in a special form. So, a new kind of rank-reduced STAP is proposed. When covdariance matrix is known, it is the same as the full dimension optimal STAP. When covariance matrix is unknown, it also has a good appearance.关键词：AEW radar;STAP;interference suppression2|322|1更新时间：2025-12-08
- 摘要：Position tracker is one of the most critical input devices for human-machine interface utilities in virtual reality and other human-machine interation systems. It determines the opition and orientation of an object of interest （such asthe user’s head） and passes the information to the host comuter in real time, which whws the virtual worid on the bois ofthe current visual point of the user. A dynamic position tracker based on continuous amplitude-modulated ultrasonic wave isdeveloped by means of the interferometric techniques. Its principles, technical implementation and experimental results are discussed. A prototype virtual reality system using the ultrasonic position tracker as an input device is also constructed and presented in the paper.关键词：position tracker;ultrasonic rangefinder;virtual reality system;virtual world2|249|17更新时间：2025-12-08
- 摘要：Elarent patterns and equivalent magnetic currents of rectangular waveguide end-slot finite phased arrays areanalysed using moment method. Effect of mutual coupling for elements in different position at different scan angle to equivalent magnetic current distribution is discussed.关键词：phased arrays;element pattern in arrays;magnetic currents2|68|1更新时间：2025-12-08
- 摘要：A new Hopfield Neural Network multiuser detector is proposed. According to the corresponding relation between the power function of Hopfield neural network and the likelihood function of maximum posterior detective probablilityfor optimum multiuser detector, a discrete Hopfield neural network multiuser, detector is constructed. It is shown that the detector complexity is lower than that of optimal detector, and precedes conventional detector in elimlnating multi-user interference and near-far reslstance.关键词：CDMA;muti-user detection;Hopfield neural network2|99|1更新时间：2025-12-08
- 摘要：The principle of multiple access communication is described, Which is based on the orthogonal wavelets inthis paper. And a multirate orthogonal modulation scheme is proposed. The goal of spreading information equence spectrum ismet by coding bit-streams with the different scaled wavelets. So this multiple access technology has a good perfomance in resisting narrow jam and interference. The other characteristics are also discussed. Some methods are given to resolve the inequity of the channel capacity.关键词：wavelet;multiple access communications;modulation;spread spectrum2|147|5更新时间：2025-12-08
- 摘要：A modification to the geometrical learning algorithm of binary neural network, which tries to enhance efficiency of the algorithm, is demonstrated. Then a new Heuristic Genetic Geometrical Learning algorithm（called HGGL algorithm） of the neural network used for arbitrary Boolean function approximation is presented. The algorithm imtroducesknowledge based crossover operator and mutation operator to optimally divede geometrical hypercube and evaluate the numberof the hidden netirons, connection weight and threshold. For arbitrary Boolean function, the neural network trained by HGGLalgorithm has the fewest number of hidden layer neurons comparde with existed leaning algorithms.关键词：genetic algorithm;neural network;learning algorithm;Boolean function2|57|1更新时间：2025-12-08
- 摘要：Based on the eloctromagnetic scattering and radiating theories, the imaging principles for sea surface at visualand infrared bands are analyzed. The relationship between the visual images and IR images at the same environment conditionare derived. A fast algorithms is provided to obtain the IR sea surface images from visual images for as surface. Finaly, several real visual images of sea surface are taken to test our method. The corresponding IR images at the same conditions are obtained successfully.关键词：electromagnetic scattering;sea surface;infrared imaging2|133|1更新时间：2025-12-08
- 摘要：By the comprehensive analysis of existing mcasuring methods, a new method is proposed in the paper tomeasure the nuclear radiation dose field with array absorption-emission computed tomography. The detector based on scintillation optical fiber array and its servo-control system are designed. The weak optical signal is measured by Charge Coupled Devices （CCD） and the formed visual signal is quickly sampled with the method of testing fixed signed points. The reconstruction method of iterative filter back projection and the data renovation based on noncomplete proection are proposed to reconstruct dase field much more accurately. The filter function is also an important factor in the image reconstruction. The Butterworth filter function is chasen. By adjusting its parameters, we have obtained optimum result. Finally, all the experimentationshow that the methods proposed in paper are proper and whole measuring system is advanced and feasible.关键词：nuclear radiation dose field;scintillation;computed tomography;iterative filter back projection;image reconstruction2|207|6更新时间：2025-12-08
- 摘要：In this paper, the maximum reative sidelobe level of a large plane array is optimized by genetic algorithm.An adaptive mutation operater is presented. Good results show that the genetic algorithm is an effective metod to solve antenna array optimization problems.关键词：antenna array;sidelobe level;genetic algorithm;optimization2|470|9更新时间：2025-12-08
- 摘要：A new kind of moent method using curved wire segments is used in this paper to analyze a kind of frequency independent antenna-two arms conical log spiral antenna. By using the curved wire Segments to represent the antenna’sstructure and the properties of the central symmetric matrix, the calculation time is much reducecl and the accuracy and speedis enhanced. This program is also suitable to plane spira and conical spiral antennas. This paper also presents a lot of data andcurves and they are verified by the references and experiments. Their results matched fairly well.关键词：moment method;central symmetric matrix;two-arm conical log-spiral antenna3|402|3更新时间：2025-12-08
- 摘要：A loaded antenna on finite ground is analyzed by using hybrid method. The charcteristics are caculated.The results demonstrate that this kind 0f loaded antenna can achieve good broadband characteristics.关键词：loaded antenna;finite ground;broadband characteristics2|266|4更新时间：2025-12-08
- 摘要：Based on the maximum kurtosis criteria and gradient decent method, this paper designed a new blind identification algorithm for noncausual AR system. Its global convergence is proved and convergence rate calculated. Parameters inthe invease filter approach the true AR coefficients by high-order cumulant （HOS） based self-study algorithm. This identification method can effectively suppress the Gaussian noise because of the utilization of HOS.关键词：noncausual system;blind identification;higher-order culmulant;maximum kurtosis criteria2|164|3更新时间：2025-12-08
- 摘要：High power CW magnetrons can be used widely in industrial heating and other aspects, and long-anode magnetrons could reach higher power because of their larger thermal capacitance and longer interaction distance than convntionalmagnetrons. In this paper, a preliminary design of a long-anode resonator for 2450 me operation was given and its charcteristics including mode dispersion and characteristic impedance etc. for different arrangement of output structure and straps werecalculated using MAFIA package. Higher axial modes,which do not exist in ordinary magnetrons were found by the study ofthe field patterns. At last, a good mode separation has been obtained for π-mode oscillation by prope straps arrangements.关键词：long-anode;resonator system;field Pattern;mode separation2|83|2更新时间：2025-12-08
- 摘要：An X-band large diameter coaxial relativistic backward wave aseillator （CRBWO） was prasented and designed in the paper. The complete dispersion relation and coupling impedance of TMon mode in the coaxial corrugated cylindrical waveguide used in the CRBWO were analyzed and calculated by FDTD method. An electromannetic particle-in-cell codeis being used to investigate the nonlinear beam wave interaction and perfonnance optimization issues of the device. The simulation results show that the CRBWO can generate GW level microwve power at X-band frequency very efficiently.关键词：coaxial relativistic backward wave oscillator;high power microwave;particle-in-cell;high frequency characteristics2|145|9更新时间：2025-12-08
- 摘要：The distribution of RF field of the slotted cylindrincal wave guide is discussed and the self-consistent nonlinear theory of the beam-wave interaction is prasented in this paper. The behavior of the slotted gyroton travelling-wave amplifier （gyro-TWT） with a uniform section is simulated by a Runge-Kutta algorithm code for a warm beam encircling around theaxis of the wave guide. Some important regulations are obtained. This work presents the bases to further studies of the pyroTWT.关键词：Gyro-TWT;slotted wave guide;self-consistent nonlinear;high harmonic wave;velocity spread2|53|1更新时间：2025-12-08
- 摘要：A novel design methed called"the replacement method"is proposed in the paper. The method can transformOTAC circuits into CFA-RC based circuits simply and directly. A design table is given to simplify the design. Design exampleand experimental results show the validity and advantages of the method.关键词：active filter;circuit theory and design;current mode;transformation method3|79|3更新时间：2025-12-08
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