最新刊期
卷 32 ， 期 6 ， 2004
- 摘要：It is difficult for common low-resolution radar to distinguish multiple planes flying in a raid cluster using traditional radar signal processing techniques.A raid cluster resolution scheme is proposed based on joint range-Doppler processing.The transmitled signal used is linear frequency modulation (LFM) signal and the received signal within observation time is represented by the summation of multiple sinusoid signals in both range and Doppler dimension.The time-delay and Doppler information are used jointly to estimate the sample covariance matrix,and the final resolution algorithm is a high-resolution source number estimation method—the new modified Gerschgorin disk estimation (NMGDE) method.The proposed scheme can give the target number automatically,and adapts to all kinds of flying states,low signal noise ratio (SNR) or short dwell time,especially middle or high repetition frequency,owing to being compatible with resolving range ambiguity by repetition frequency irregularity.关键词：raid cluster resolution;formation flight;low-resolution radar;range-Doppler processing;Gerschgorin disk estimation (GDE)2|1503|5更新时间：2025-07-16
- 摘要：In this paper,a new hybrid filter algorithm based on triangle modulus fusion operator was proposed to overcome the shortcomings of the hybrid linear and nonlinear filter techniques.Based on the properties of competition,complementation and redundancy of information fusion,this algorithm makes fusion decision about the boundary point using the triangle modulus operator,then performs hybrid filtering based on the fusion results.This new algorithm can overcome the shortcomings of the decision with single source,i.e.,high error risk,low reliability and fault tolerance,therefore improve the filter performance very well.The following experiments demonstrate the validity of this new algorithm and prove that it provides a novel approach for image filter technology.关键词：Information fusion;triangle module operator;minimum total error probability criterion;neyman-pearson criterion;hybrid filtering2|880|1更新时间：2025-07-16
- 摘要：The paper proposes a new rule of image fusion.We start with taking local Fourier Transform of high frequency sub-images in image fusion based on the pyramid and Wavelet Transform,get their harmonious energy,then consider the ratio of these energy and the energy of the corresponding area in the low frequency image as the rule of pixels choice.We apply the rule in multi-focus image fusion and multi-band remote sensing image fusion and conclude that the efficient fusion rule is better than current principle in some fields.关键词：image fusion;Fourier transform;harmonious energy;image pyramid;wavelet transform2|1339|2更新时间：2025-07-16
- 摘要：Markov chain Monte Carlo (MCMC) methods are considered as the powerful techniques for Bayesian computation.However,it is difficult to apply them to the asynchronous CDMA systems in the presence of unknown interferences and multipath fading.In this paper,a novel Bayesian multiuser detection method is proposed to overcome the difficulty.In the proposed method,the received signal is preprocessed at first by the linear group-blind decorrelator,and then,the Gibbs sampler (a typical MCMC procedure) is employed to perform the Bayesian multiuser detection.Simulation results show that this method significantly outperforms the linear group-blind multiuser detection with a low additional complexity linear with the number of intra-cell users.To improve the performance of the proposed method,two stage Gibbs samplers are used.In the first stage,the parameter estimation with high accuracy is achieved based on the output of the Gibbs sampler and the estimated parameters are used in the Gibbs sampler of the second stage.It is seen that the detection performance is improved in comparison with that of the method using one stage Gibbs sampler.2|926|1更新时间：2025-07-16
- 摘要：An analysis of the antenna and scattering theory is an important part in the electromagnetic problems,which describes the energy transformation from a closed circuit system to an open space system.This paper presents a general circuit model unifying the exciting sources and loaded networks.Furthermore,the interaction of circuits and fields is unified in the generalized matrix Ohm's law that is given in this paper.It is shown that the sources or load networks,as the circuits,produce coupling to the antenna or scattering bodies so they affect the near fields and radiated pattern.关键词：unified circuit model;generalized matrix Ohm's law;interaction of circuits and fields2|996|1更新时间：2025-07-16
- 摘要：In combined field integral equation (CFIE) method for solving electromagneticscattering from conductive target with open cavity,there appear both EFIE operator and MFIE operator imposed on unknown combined sources,resulting in complicated calculations.In this paper,a equalized CFIE has been derived,in which the integral operators imposed on electrical and magnetic currents are simply same,and the computation complexity is reduced dramatically due to this single operator in ECFIE.Combination of ECFIE with multilevel fast multipole algorithm (MLFMA) can easily solve electromagnetic scattering from conductive target with open cavity.The numerical examples in this paper show the high precision and high efficiency of this method.关键词：electromagnetic scattering;target with cavity;combined field integral equation;MLFMA;equivalence principle2|973|1更新时间：2025-07-16
- 摘要：In many practical problems,one often needs to determine the entire frequency characteristic of objects.To fast and accurately analyze,a hybrid method combining automate multipoint well-conditioned asymptotic waveform evaluation(AMWCAWE) with MNM is presented in this paper.Firstly,single point well-conditioned asymptotic waveform evaluation(WCAWE) technique is developed into multipoint well-conditioned asymptotic waveform evaluation(MWCAWE).Then relative residual is defined to automate MWCAWE.When ineffective bandwidth is very narrow,a novel iterative technique-MNM is employed to substitute a new expanding point,which improves the computing precision,efficiency and also saves memory.At last,the scattering characteristic of several representative PEC objects is analyzed using AMWCAWE with MNM throughout the entire frequency band.Numerical examples are given to illustrate accuracy and robustness of this method.关键词：AMWCAWE－MNM;WCAWE;MWCAWE;MNM2|659|2更新时间：2025-07-16
- 摘要：This paper first proposes a novel Multi-Universe Parallel Quantum Genetic Algorithm (MPQGA) and proves its global convergence in theory.In the algorithm,all individuals are divided into some independent sub-colonies,called universes,according to their definite topological structure.Individuals in a universe are represented by multi-state gene qubits.In the individual's updating,the general quantum rotation gate strategy and dynamic adjusting rotation angle mechanism are applied to accelerate convergence.Quantum NOT gate is used to realize quantum mutation to avoid premature convergence.Each universe evolving independently enlarges the search space.Information among the universes is exchanged by adopting the best emigration and the quantum crossover operation for the improvement of search efficiency.Then it puts forward a new Blind Source Separation (BSS) method based on the combination of MPQGA and Independent Component Analysis (ICA).The simulation results show that the efficiency of the new BSS method is obviously higher than that of the Conventional Genetic Algorithm (CGA) and the Quantum Genetic Algorithm (QGA).关键词：quantum computation;genetic algorithm;quantum genetic algorithm;multi-universe parallel quantum genetic algorithm;blind source separation2|3118|43更新时间：2025-07-16
- 摘要：Real-time tracking plays a key roll for ocean radar altimeter (RA).In this paper,the maximum likelihood estimation (MLE) algorithm for RA is studied,including the scheme,the errors,and the realization.The α-β filter is also analyzed.A tracker for spaceborne RA based on sub-optimal maximum likelihood estimation (SMLE) was developed,and by which a lot of ocean echo signal curves were obtained successfully in the airborne flight experiment.This was the first time for China to obtain ocean echo signal curves based on SMLE,and it was a great step for China to develop spaceborne RA.关键词：radar altimeter;maximum likelihood estimation algorithm;tracker2|1391|2更新时间：2025-07-16
- 摘要：In the space-borne SAR quick-look processing,it can not satisfy the process precision and the process speed simultaneously with the conventional quick-look algorithms,SPECAN,RD+FIR,etc,to process the echo data which has large range migration.To solve this problem,this paper presents a quick look algorithm:ECS+FIR (Extended Chirp Scaling and FIR filter) algorithm,which is based on the equivalent slant range model.The computation amount of this algorithm will not change with the increase of the range migration,so it is quite suitable to process the space-borne SAR echo data with large range migrations.In addition,this algorithm uses sub-aperture data in the azimuth processing instead of the FIR filter in azimuth,which reduces the computing amount.The principle and flow chart of the algorithm are discussed in details,and a comparison between the ECS+FIR and other quick look algorithms has been made.Several simulation study results are given to demonstrate the feasibility of the algorithm.关键词：synthetic aperture radar;quick look processing;ECS algorithm;FIR filter2|1275|5更新时间：2025-07-16
- 摘要：The partially polarized signal detection is investigated for the first time based on the polarization sensitive array.The signal detection is modeled by the binary hypothesis test.Under Gaussian distribution,the likelihood ratio is obtained by exploiting the matrix eigendecomposition.The detecting scheme is presented according to the statistical test.The probability distribution function is acquired under the null hypothesis and the alternative hypothesis respectively.According to the Neyman-Pearson rule,the probability of detection is calculated at a certain probability of alarm.Furthermore,especially,the detection performance is analyzed under structured noise.How the factors affect the detection performance is drawn from a series of numerical examples,such as the polarization degree of signal,the Interference to Noise Ratio,the polarization degree of interference and the arrival angle of interference.关键词：polarization sensitive array;signal detection;partially polarized;performance analysis2|1153|3更新时间：2025-07-16
- 摘要：Aiming at the detection problem caused by the maneuvering target under addtive and multiplicative color noise,the detector based on cyclic statistics is constructed,then the relation of detector versus SNR is concluded.The detector properties under various SNR are presented through analyzing the property of the complex LFM signal disturbed by both addtive and multiplicative color noise In the end ,the character of the detector and preference is given through Monte-Carlo test in compare with the Wigner-Hough detector.关键词：cyclostationary;cyclic moments;linear frequency-modulated;detector;signal-to-noise ratio2|900|2更新时间：2025-07-16
- 摘要：A new method for line detection,Adaptive Fuzzy Hough Transform (AFHT),is introduced.Based on the fuzzy mapping of edge pixels by local gradient orientations,the AFHT calculates the actual line parameters for each pixel by fuzzy reasoning with the fuzzy accumulator array as global constraints,and detects straight line segments through a reaccumulating procedure.Experimental results demonstrate that the proposed algorithm has small computational requirements,high detection accuracy,and the capability of providing complete line segment description.关键词：line detection;adaptive fuzzy Hough transform;fuzzy reasoning;complete line segment description2|1057|11更新时间：2025-07-16
- 摘要：A new preprocessing method is proposed for joint direction-of-arrival and frequency estimation in the presence of coherent signals by effectively extending the forward/backward spatial smoothing technique in the 1-D case to the spatio-temporal array data matrix in the 2-D case.This paper analyzes in detail how to construct the forward/backward smoothed spatio-temporal array data matrix and the conditions under which the identifiability of signal parameters is guaranteed.Unlike the existing methods using only the forward spatial smoothing technique,the performance of the proposed method is greatly improved due to utilizing both the forward and backward spatial smoothing technique.It requires few sensors,exhibits high accuracy and resolution and performs well under low signal-to-noise ratio (SNR).关键词：coherent signals;spatio-temporal array data matrix;forward/backward spatial smoothing2|644|0更新时间：2025-07-16
- 摘要：To satisfy the requirement of high location speed and stability,an algorithm for 3-D moving emitter passive location and tracking using measurements of time of arrival (TOA),direction of arrival (DOA) and azimuth angle changing rate by single non-moving observer is given in this paper.Based on the kinematics theory,this algorithm takes full advantage of the spatially and temporally changing information of the measurements from the emitter,and has high convergence speed and stability,so it's of great practicability.Finally,the computer simulation results are presented.关键词：passive location;velocity vector;azimuth angle changing rate;kinematics4|1060|7更新时间：2025-07-16
- 摘要：Using the significant spectral correlation within the hyperspectral images,a lossless compression algorithm is presented in this paper.The method can be explained in two steps:(1)band ordering according to spectral correlation coefficient;(2)3-D adaptive prediction based on neural networks.Experiments show that this method can remove the spatial and spectral redundancy efficiently.The proposed approach can reduce about 0.3 bit per pixel compression compared with JPEG-LS.关键词：hyperspectral image;lossless compression;band ordering;adaptive prediction2|1286|15更新时间：2025-07-16
- 摘要：This paper presents a novel approach to video indexing.In this approach,we define a people-similarity measure according to both clothing similarity and speaking voice similarity.Such similarity depicts how perceptually similar two people appearing in different scenes are and whether they belong to an identical person.The extended support vector machines are applied to map a serial of low-level feature distances to a perceived people-similarity.To build people-similarity based video indexing,a novel unsupervised clustering algorithm is also proposed,which can more correctly group individual person according to the mutual people-similarities among multiple people pairs.关键词：video indexing;people-similarity;machine learning;unsupervised clustering algorithm2|908|2更新时间：2025-07-16
- 摘要：An extended ESPRIT type method was presented to extract frequencies from the signal which was contaminated by two-dimensional colored Gaussian noise.If the noise has the characteristic of MA model,this method can restrain it effectively.In addition,a new pairing method was also presented.Theory and algorithm are illustrated by simulation examples.关键词：two-dimensional;ESPRIT;colored Gaussian2|870|1更新时间：2025-07-16
- 摘要：This paper presents a fast motion estimation search algorithm with adjustable predictive quality.Taking advantage of the spatial and temporal correlation of motion vectors,motion estimation of the algorithm is realized by predicting initial search center location,analyzing whether a silent macroblock or not,adjusting windows size,and using progressive block matching measure of adjustable predictive quality,and at the same time,introducing adjustable function to add controllability between predictive quality and searching speed.Experimental results show that the algorithm can reduce computation amount significantly,increase computing speed greatly,provide good reconstructed video quality,and be applied for low bit rate video encoding.关键词：adjustable predictive quality;progressive block matching measure;motion estimation;video encoding2|728|2更新时间：2025-07-16
- 摘要：A new sigma-delta modulator is proposed by designing a new noise-shaping filter.By use of this modulator,the input signal can be represented as a signal with lower bits.The number of the output bits of this kind of modulator is greatly decreased,in contrast to the traditional sigma-delta modulator.Theoretical analysis and simulations for this modulator show that it has a great improvement in quantizing noise shaping and noise frequency spectrum.The stability of this kind of modulator is also proved.关键词：Σ－Δ modulator;noisy shaping filter2|843|1更新时间：2025-07-16
- 摘要：This paper firstly introduces the basic principle of the angular measurement between boresight and LOS (the line of sight) of conical scanning system,and the method of angular measurement using one dimensional range profile for small size MMW seeker of High Range Resolution stepped frequency radar is presented.Secondly,the influence of Doppler effect on the angular measurement is analyzed.Finally,some experimental results are given.关键词：stepped frequency;one dimensional range profile;conical scanning3|1078|1更新时间：2025-07-16
- 摘要：The Wigner-Ville distributions of symmetrical sensors are used to project the data from element space to time-frequency beamspace ,then a novel spatial time-frequency data model with a separable structure is achieved.Based on this model,beamspace-ESPRIT and subspace projection can be used respectively to get the instantaneous frequency and 2-D AOA of impinging signals.Simulation shows the efficacy of the proposed algorithm.关键词：wideband LFM signals;instantaneous frequency;time-frequency beamspace4|1021|3更新时间：2025-07-16
- 摘要：Quasi-continuous wave radar signal has solved the problem of separating transmitingfrom receiving ,and its application has aroused the regards of radar community.This paper firstestablishes the mathematical model of Quasi-continuous wave binary-phase-code signal;thenconcludes the average ambiguity function of Quasi-continuous wave binary-phase-code signal;later we adopt a kind of special binary sequence——MAC sequence,by which we make 0 and π phase modulation of Quasi-continuous wave radar signal;finally the results of computersimulation of the signal performance are given.2|1023|4更新时间：2025-07-16
- 摘要：On the basis of analyzing the extension of beam width of phased array radar,the optimal beam position arrangement in complicated spaces is discussed.A new method based on boundary-confined algorithm is proposed with an example in the paper,which converts the dynamic and non-linear problem to graphics theory.Then compare the overlying and overlapping ratio among different arrangement patterns and draw out some conclusions.Finally,the curve between beam position number and intersectant voltage value is obtained according to some phased array radar.关键词：phased array radar(PAR);beam position;optimal search strategy;boundary-confined5|2291|20更新时间：2025-07-16
- 摘要：Traditional asymptotic waveform evaluation (AWE) with Moment of Method (MoM) for frequency response fast calculations is analyzed deeply.And an important conclusion is drawn:ill-conditioned coefficient matrix of Pade approximation may be resulted from traditional AWE.Well-conditioned asymptotic waveform evaluation is thus introduced.And an implementation of WCAWE is presented for obtaining the frequency response of the Radar Cross Section (RCS) of arbitrarily shaped three dimensional perfect electric conductor (PEC) bodies.Examples given demonstrate that the numerical computation efficiency is improved drastically using WCAWE.关键词：Mom;AWE;Padé approximation;WCAWE2|867|1更新时间：2025-07-16
- 摘要：A new fragile watermarking scheme is presented,which is capable of authentication,tamper-proofing and integrity verification of digital products.Let the grayscale values of host image map the initial values of the chaotic mapping.The watermark obtained by iterating several times of the chaotic mapping,is embedded into the LSB (Least Significant Bit) plane of host image.The proposed scheme can localize the tampers on the watermarked image by using to the high sensitivity on initial value of the chaotic mapping.Moreover,no host image is needed in watermark extraction.Our simulation results show the effectiveness,sensitivity and localization of tamper-proofing of this technique.关键词：fragile watermark;chaos;verification2|1193|16更新时间：2025-07-16
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Passive Tracking Based on Data Association with Information Fusion of Multi-Feature and Multi-Target
摘要：A new data association algorithm based on information fusion of multi-feature and multi-target in passive tracking is proposed in this paper. It uses more features of the target such as the frequency, PRI, while the traditional algorithms only use the features directly correlative with the target state such as DOA, TOA. Based on the information fusion of multiple features with DS evidence theory, the decision of synthetic data association of all the targets is made. With the help of computer simulation, it is proven that the proposed algorithm is superior to the NN method and the expanded NN method.关键词：passive tracking;Information fusion;data association2|1675|18更新时间：2025-07-16 - 摘要：This paper analyzes the relation between the Doppler rate and phase gradient,and proposes algorithm for the Doppler rate estimation with the PGA,then the performance of this algorithm is verified by the computer simulation data and airborne SAR data.The result of theoretical analysis and simulation shows that this algorithm has less operation load and faster convergence speed as well as the improved estimation accuracy.关键词：PGA;SAR;phase gradient;Doppler rate2|1157|5更新时间：2025-07-16
- 摘要：A novel compensation circuit of electrically small antennas is presented, in which a short-circuited transmission line shunted with the antenna is used to realize the broadband matching. Optimizing design scheme is obtained in the premise of ensuring the given VSWR and improving efficiency. The compensation ability of the circuit is discussed in detail by calculating numerically parameters of the whole circuit such as impedance, VSWR, efficiency and gain etc.. This is a general design method for optimizing an electrically small antenna because it does not deal with concrete configuration of antennas.关键词：electrically small antenna;compensation circuit;short-circuited transmission line;broadband matching;numerical calculating;optimistic design2|2006|2更新时间：2025-07-16
- 摘要：The ion barrier film at the input of the microchannel plate(MCP) plays an important role in improving the lifetime of the third generation image tube.The advantages and disadvantages of existing ion barrier films are analyzed, and a novel ion barrier film causing no carbon contamination in inner channel surface is proposed.A 4nm thick Al2O3 ion barrier film at the input of MCP is fabricated.Theion barrier and electron transmission effectiveness of ion barrier film at theinput of MCP are measured.Results of the experiment show that a 4nm thick Al2O3 ion barrier film is characterized by ion feedback prevention and high electron transmission.关键词：microchannel plate;ion barrier film;image tube2|876|0更新时间：2025-07-16
- 摘要：The analysis and simulation for the thermal condition of pulse helix TWT against a foreign product are given. Through its process, the requirements for the thermal design could be understood quite well and the necessary technology measurement could be taken by the manufacturing engineers.It also leads to improve the reliability for the same kind of TWT.The surface thermal resistivity is measured,and the primary analysis shows how to reduce the surface thermalresistivity by various methods.With the help of ANSYS,the thermal condition ofpulse helix TWT has been simulated,its results consistent with the design calculation in the main area are more accurate and reliable.关键词：pulse helix TWT;thermal condition;temperature;simulation2|1349|6更新时间：2025-07-16
- 摘要：Graphical Electromagnetic Computing(GRECO) is extended to bistatic Radar Cross Section(RCS) calculation of Complex Target in high frequency band by Physical Optics(PO) and Incremental Length Diffraction Coefficients(ILDC).Some standard targets' bistatic RCS obtained by the approach coincide with those obtained by different approaches.This approach is applicable for the research works of radar networking and stealth or anti-stealth technology.关键词：EM scattering;bistatic RCS;physical optics;incremental length diffraction coefficients3|2583|9更新时间：2025-07-16
- 摘要：The modified difference equation near the sharp metal edge in FDTD grid is presented in this paper.In order to test the efficiency of new FDTD equations,we use a stripline and V-shape antenna,which have two sharp edges diagonal to the cell cube in FDTD grid.Compared with staircase approximation, a dramatic improvement in computed accuracy is observed.关键词：metal edge;finite-difference time-domain(FDTD);stripline2|1060|3更新时间：2025-07-16
- 摘要：With various multimedia applications rapidly advanced in the current INTERNET,the frequent occurrence of congestion has led many researchers to re-examine the issue of congestion control.At present,the congestion control technologies we master and use adopt end-to-end control which regards TCP as core and is based on window.However,this art has its own drawbacks such as high packet loss,low response speed etc.In this study,the authors give a queue managing algorithm based on priority and self-adaptation.The algorithm is called Priority Random Early Detection (PRED).The algorithm can make router more accurately schedule queue.The primary parameter of algorithm can adapt dynamic change of network load in true surroundings.Validly,it avoids the drawbacks of congestion control we master.Experiments prove,under the same configurations,that PRED algorithm is better than end-to-end congestion control arts in terms of reducing the rate of packet loss and oscillation of queue.关键词：queue manage;priority;RED;self-adaptation2|840|2更新时间：2025-07-16
- 摘要：By treating time domain separated echoes,caused by the scatters on the target,as a pulse train with random parameters,a new detection method is proposed for high resolution radar target detection based on the theory of optimum detection and the characteristic of target's echoes in a high-range-resolution radar.Computer simulation shows that the new method has at least 2dB improvement in detection performance compared with the traditional detection method.关键词：high resolution radar;signal detection;matched filter2|1305|8更新时间：2025-07-16
- 摘要：A new Mix net protocol is presented.Given an array of encrypted messages,two different groups of mix servers blind and decrypt the same array,which makes our protocol(t,N-2)AA-resilience.Its communication and computing costs are less than other verifiable Mix net that we know presently.A secure electronic voting scheme based on it is also proposed which has the following property:privacy,fairness,publicity,public verifiability,and voter's anonymity simultaneously.关键词：electronic voting;Mix net;voter's anonymity;public verifiability2|1054|4更新时间：2025-07-16
- 摘要：Based on model matching approach,this paper presents an algorithm for designing optimal filter that minimizes the magnitude of the filter error,in the case of linear discrete-time system in which the process noise and measurement noise are unknown but magnitude bounded.The presented algorithm can be used to optimal infinite-horizon filter design.When the initial condition of the system is a priori known,the optimal filter is converted into a standard tow-block 1 optimization.When the system contains unknown but bounded initial condition,the optimal filter can be obtained by solving finite standard 1 optimization problems that can be solved by existed techniques.A simulation example shows the effectiveness and feasibility of the proposed results.关键词：optimal filter;unknown initial conditions;unknown but bounded noise;1 norm optimization2|714|1更新时间：2025-07-16
- 摘要：Based on the introduction of multiwavelets and their pre-processing methods,the influence on multiwavelet filters response with the different pre-processing methods are discussed and compared in this paper.Through the analysis of multiwavelet transformation of noise signal,the denoising method is presented.The denoising effect of power system fault transient signals with traditional wavelet and multiwavelets based on different pre-processing methods is analyzed and compared after a great deal of simulation work.The results indicate that the choice of pre-processing methods is a key factor,and the denoising effect of transient signals with multiwavelets based on proper pre-processing methods is better than that with traditional wavelet.关键词：multiwavelet;pre-processing method;denoising2|1190|4更新时间：2025-07-16
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