最新刊期
卷 33 ， 期 12 ， 2005
- 摘要：The ESPRIT super-resolution ISAR imaging algorithm doesn't use the conjugate of observation data and it can't estimate the number of scattering centers.For overcoming those shortcomings,a new ISAR imaging algorithm is proposed based on the Unitary ESPRIT technique.Unlike previous ESPRIT imaging algorithm,the new method uses Gerschgorin disk theorem to estimate the number of scattering centers and it improves performance of signal estimation,since the observation data are incorporated with their conjugate.By constructing Centro-Hermitian matrices,the algorithm also provides a reduced computational burden.The validity and feasibility of the new algorithm are verified by using simulated and measured experimental data.关键词：unitary ESPRIT;radar imaging;gerschgorin disk theorem;super resolution4|951|6更新时间：2025-07-16
- 摘要：Time-varying fading channel greatly challenges the accurate channel estimation.This paper proposes a method for time-varying channel parameter estimation based on fractional Fourier transform.According to the channel parametric model,a multicomponent LFM signal is sent to detect the channel.At the receiver,fractional Fourier transform is implemented to estimate the parameters of LFM signal and finally obtain the parameters of time-varying channel.Theoretical analysis and simulation results show that the proposed algorithm exhibits good performances and has a low computational complexity.关键词：LFM signal;parameter estimation;fractional Fourier transform4|994|7更新时间：2025-07-16
- 摘要：The paper proposes two raw data based approaches for two aperture SAR-GMTI.The method of DPCA-Radon successfully detects and estimates parameters of moving targets in clutter-free environment.The method of DPCA-Frft-ATI achieves these purposes in clutter-rich environment and performs superiorly than commonly used raw data based method and image-based detector via improvement of signal to clutter ratio,also it can focus and relocate moving targets.Simulation results indicate feasibility and effectiveness of the methods.关键词：synthetic aperture radar;ground moving target indication;displaced phase center antenna;along track interferometry;fractional Fourier transform2|868|4更新时间：2025-07-16
- 摘要：In this paper,a new method based on multiscale autoregressive moving average (MARMA) models is presented to compress SAR(Synthetic Aperture Radar)image.The method uses the multiscale representation as the cornerstone of the modeling process,and constructs the MARMA models of image.Thus we predict the initialized image data using these multiscale models,and the compression is subsequently achieved through coding the residual image.Unlike published methods,supervising segmentation for SAR image is not used in our compression processes.So the prior knowledge of segmentation is not required.Experimental results have proven that the proposed method achieves high compression radios with impressive image quality.关键词：SAR image compression;multiscale autoregressive moving average(MARMA) model;residual image4|1029|1更新时间：2025-07-16
- 摘要：A recursive back projection(BP) imaging algorithm is presented.Real time imaging is an intense demand but a challenging task in impulse surface penetrating radar(ImpSPR)’s application.Based on 'delay-sum’ operation in time domain,BP imaging algorithm can precisely focus scattering intensity and obtain high quality subsurface profile.But its heavy computation load restricts its application in ImpSPR's real time processing.After analyzing BP imaging procedure,a recursive model of this imaging algorithm is established and recursive BP imaging algorithm is educed subsequently.The computation complexity of both original BP imaging algorithm and recursive BP imaging algorithm are analyzed.Through processing experimental data obtained by a ImpSPR system-RadarEye,the recursive BP imaging algorithm validate its capability at the aspect of ImpSPR's real time processing.关键词：impulse surface penetrating radar;back projection;real time imaging3|1220|6更新时间：2025-07-16
- 摘要：The method of single observer passive location using look-acceleration and angle rate of changing information is put forward.The paper analyse the location fundamental and point out that this method have advantage of single measurement location to static or movement emitter with same speed.At the same time the tracking arithmetic(MSKF) adapting to this location method is put forward.Finally,the computer simulation and outfield test of single measurement location and MSKF tracking arithmetic prove that this method is effective.关键词：passive location;look-acceleration;angle rate of changing;target tracking4|1097|12更新时间：2025-07-16
- 摘要：An efficient two-scan data association method based on an interior point linear programming approach is analyzed.Based on this method,a new algorithm that is combined with the interacting multiple model is presented to track multiple maneuvering target.With the improved accuracy and reduced computation burden of two-scan data association,the accuracy and speed of the new algorithm presented here are improved greatly.The numerical analysis and computer simulation demonstrate the new algorithm is far more efficient than the existing IMMJPDAF algorithm.关键词：multiple maneuvering target tracking;two-scan data association;interacting multiple model two-scan data association2|1383|4更新时间：2025-07-16
- 摘要：This paper introduces briefly MPCSAR principle and its current research situation about the nonequivalent relationship between spatial and time,studies the false target image appearing in the form of pairs of echo when the relationship between platform velocity and PRF fails to be matched.The location formulas for pair of echo in MPCSAR are deduced strictly.Two types of false image(under-sampling false target image and mismatched false target image) are analyzed.A phase compensation method in frequency domain to eliminate these pairs of echo is proposed in the paper also.The conclusions of this paper are verified by simulation.关键词：multiple phase center SAR;pair of echo;false image;phase compensation4|907|3更新时间：2025-07-16
- 摘要：For the noise suppression and target's feature-extraction of the synthetic aperture radar (SAR) imagery in complex domain,a regularization method based on lk norm is presented in SAR complex imagery domain in terms of the sparse prior of SAR imagery.The design of the algorithm and the research on its convergence assure the feasibility and robustness of this method.The coupling between the regularization method and ridge estimate afford a new idea of the choice of the regularization parameters.Numerical results demonstrate that our method can efficiently depress noise and extract the target's feature of SAR image.关键词：SAR;sparse representation;noise suppression;feature extraction;regularization;ridge estimate4|929|8更新时间：2025-07-16
- 摘要：This paper focuses on nonlinear effects on both amplitude and phase of a Chirp signal,and also on pre-compensation method for removing these effects.In a radar system,working distance is mainly decided by transmitted power,the more the power,the longer distance the radar can detect.High power amplifier (HPA) often works at saturation point in order to get high output power,but brings on nonlinear effect on output radar signal.The nonlinear effect degrades the performance of Chirp signal greatly.We analyze the main lobe width and first side lobe due to these effects.We propose two methods for pre-compensation based on DDS,i.e.table-checking method and iterative method.Theory and simulation results show thatthese two methods reduce these effects efficiently.Finally,we analyze the factors that influence the performance of these two pre-compensation methods,as well as the convergence issue for the iterative method,and compare their results.关键词：high power amplifier (HPA);nonlinear distortion;precompensation;pulse compression4|1464|3更新时间：2025-07-16
- 摘要：This paper briefly proposes a new different spectral density from power spectrum density of the second order processes,thus we can get a new concept of stable white noise based on covariation spectrum,and a method of whitening in nonlinear system under alpha-stable conditions.Simulation and analysis show that the method is robust and generalizes the conventional whitening filters based on second order statistics.关键词：alpha stable distribution;covariation sequence;covariation spectrum;covariation function;PAR2|1373|3更新时间：2025-07-16
- 摘要：A fast algorithm of edge-element is presented for the computation of the high-order-modes in dielectric-loaded waveguides with arbitrarily transverse cross-sections.Numerical examples show that this algorithm requires greatly less memory and has significantly higher efficiency,compared with the previous algorithm.The relation between computation accuracy and division mesh is investigated numerically.The computations of propagation constants of the eigen-modes in rectangle waveguides and various dielectric-loaded waveguides demonstrate the high efficiency and accuracy of the proposed algorithm.At last,the eigen-modes in the interior-coated waveguide are investigated with the developed code based on our proposed algorithm.关键词：fast algorithm;edge element;high-order-modes;dielectric loaded waveguide2|1186|0更新时间：2025-07-16
- 摘要：The Discrete Complex Image Method (DCIM) is usually used to evaluate the Sommerfeld integrals for the spatial domain Green's function.To solve large scale problems,the far-zone interactions in the Method of Moments (MoM) can be simplified using a far field approximation with the plane wave expansion.Therefore,the combination of DCIM and Fast Multipole Method (FMM) could not achieve high efficiency due to the poor convergence of the addition theorem.An efficient algorithm combing FMM and Fixed Real-Image Simulated Method (FRISM) is presented to analyze microstrip structures.The fixed image locations lead to fast and convenient computations comparing with complex image such that can be used for wide-band applications.The accuracy and efficiency of the novel method are verified by numerical examples.关键词：FMM;addition theorem;Green's function;FRISM3|1009|1更新时间：2025-07-16
- 摘要：An adaptive weighting algorithm is proposed based on the adaptive null beamforming technology,which can be used for forming arbitrary sidelobe shape beam patter n for arbitrary structure arrays,considering the effect of element directivity at the same time.Three steps are given to implement the new algorithm;by presetting the sidelobe shape and sidelobe level and having cycle steps,the real beam patter n will close to the presetting one.The new algorithm is applied to arrays such as uniform linear array and parabola array as examples and compared with Dolph-Chebyshev ( DC ) weighting algorithm,and all the examples have the desired results.It is shown that the element directivity has little effect on the beamforming by the new algorithm and that the new algorithm can eliminate the effect of the broadband element directivity in broadband beamforming.关键词：beamforming;arbitrary shape sidelobe;adaptive weighting;element directivity2|879|1更新时间：2025-07-16
- 摘要：Finding a multi-constrained path is an important potential solution to provide quality of service (QoS) for next-generation networks,where the scalability and routing performance are still open problems.We propose an approach,clustering-based distributed precomputation algorithm,to the problem.Aiming to precompute the routing table with multiple QoS parameters,we introduce the extended distance vector with multiple QoS parameters,based on which the distributed computation greatly decreases the computational complexity on a single node.After dominating path selection is analyzed to omitting numerous dominated paths,a clustering technique is further presented for dominating path aggregation in routing computation.These two techniques in tur n achieve efficient aggregation of the QoS routing table.Simulation results confirm that the proposal not only has low computational complexity,but also achieves high routing performance with good scalability on both QoS parameters and the network scale.The proposal also provides an important basis to further study the interdomain QoS routing.关键词：multiple constraints;distributed computing;QoS (quality of service);routing;precomputation2|878|1更新时间：2025-07-16
- 摘要：Face detection is important in the processing of images and video.Based on multilevel gradient energy (MGE),an algorithm of face detection in DCT (Discrete Cosine Transform) compressed domain is presented.In preprocessing procedure,skin color segmentation based on the DC of chromatic components is applied to the input image for reducing the detected regions.According to the map of skin segmentation,MGE based feature vector is extracted,viz.normalized feature vectors are extracted from the detecting windows of various sizes to describe faces of different sizes.Then cascade classifier is employed to classify the feature vectors as face or non-face.Cascade classifier is comprised of several simple classifiers and a neural network classifier.Lots of feature vectors that belong to non-face are removed by simple classifiers which embedded preknowledge rules.The left vectors are classified by neural network.We combined MGE features together with image scaling to allow faces of various sizes.The simplicity of feature extraction accelerated detection by reducing the times of image scaling which is more time cost.The experiment results show that the proposed method is efficient and effective.关键词：face detection;DCT;compressed domain;multilevel gradient energy2|971|2更新时间：2025-07-16
- 摘要：This paper proposes a robust watermarking algorithm for volume data based on three-dimension discrete cosine transform (3D-DCT) and spread-spectrum communication technique.Original binary image watermark is mapped to volume watermark,which can be directly embedded to the host,with spread-spectrum communication technique.The block 3D-DCT is applied to the volume watermark and the original volume data,respectively,to implement watermark embedding.The embedded watermark is invisible and withstands the common attacks such as cropping,adding noise,filtering and rotation.The validity of proposed algorithm has been confirmed with experiments.关键词：digital watermarking;Volume Data;3D-DCT;robust2|1047|6更新时间：2025-07-16
- 摘要：Coalition Generation is a key topic in Multi-Agent System.It mainly researches how to generate the optimal task-oriented coalition in dynamic manner.This paper adopts Ant Colony Algorithm to solve the problem,and presents an Ant Colony Algorithm based multi-task coalition serial generation algorithm.This method can generate the optimal coalitions one after another for the task alignment,avoid the coalition locking and resource wasting,and the lear ning ability of ant colony system can reduce the searching time and computing works effectively.关键词：multi-agent system (MAS);coalition;ant colony algorithm;pheromone2|1103|18更新时间：2025-07-16
- 摘要：A monitoring strategy for visual navigation in multi-object environment with only one PT(Pan-Tilt) camera based on rough set theory under finite-state machine frame is proposed.The model to estimate the reliability level of multi-object orientation and an algorithm to calculate the objects priority are defined firstly.Then a finite-state machine model to monitoring each object is put foreword.A minimal rule set for monitoring multi-object is achieved by using reduction algorithm of rough set theory.Also a description method of reduction based on not-value property is proposed which is not included in the classical rough set theory.The validity and practicability of the strategy are proved by the experiments accomplished by using autonomous mobile robots to finish certain tasks in multi-object environment.关键词：visual navigation;finite-state machine;rough set;reduction;dynamic environment2|825|0更新时间：2025-07-16
- 摘要：Adaptive Local Wave Analysis (LWA) is a new effective method for processing non-stationary data.In this paper,the characteristics of the LWA,such as the physical meaning of the intrinsic mode functions,instantaneous frequency,having better joint time-frequency resolution than Wavelet Analysis,without cross terms that exist in Wigner-Ville distribution analysis,and 2-dimension LWA application in image processing,are discussed.关键词：non-stationary data;adaptive time-frequency analysis;2-dimesion Local Wave Analysis2|874|2更新时间：2025-07-16
- 摘要：The principle and the technical development of optically controlled phased array radar are discussed.The applications and the advantages of the optical electronic techniques in wideband and wide scanning angle phased array radar are introduced.The structure principles and the features for different types of OTTD's (Optical True Time Delay) are presented in detail.Also,the optical modulation and detection techniques involved in radar microwave signal transimission are discussed,and the possible applications of optically controlled phased array radar techniques are pointed out.Finally,some implementation techniques for optically controlled phased array radar,such as the rational sub-system parameter assignment,the consideration for optical device temperature performance in array architecture designing are discussed.The efficient optical transmission link must be designed carefully so as to get identical amplitude and phase responses,high signal dynamic range,low nonlinear phase distortion.In the OTTD fabrication,the beam switching time,insert loss,crosstalk,time delay error must be considered seriously.To solve the problem of OTTD fabrication error in system level,the idea of joint beam steering controlling in sub-array and antenna element are proposed.关键词：optical true time delay;optically controlled phased array radar;wideband phased array antennas;optical switch;microwave photonics2|4157|15更新时间：2025-07-16
- 摘要：Wireless position location has received considerable attention in CDMA cellular radio networks over the past few years.The process of calculating the location estimate can be views as consisting of two parts.The first part provides estimates of location parameters and the second part is the algorithm that uses the parameters to determine the MS's position.Based on the methods of location estimating and location parameter estimating,the development history of current and future challenges in wireless position location are reviewed and location estimating techniques for mitigating the influence of non-line-of-sight(NLOS) propagation are discussed.关键词：wireless location;parameter estimation;non-line-of-sight(NLOS) propagation2|2132|6更新时间：2025-07-16
- 摘要：A new method of selective enhancement for FGS is proposed,in which the base layer is encoded with an H.264-compliant encoder,while the enhancement layer,by using the outcome of mode decisions within the base layer,is encoded after performing unequal enhancement on motion compensated sub-blocks of varying partition size.H.264 uses tree-structured motion compensation featuring a flexible hierarchy of partition sizes.In general,a large partition size is appropriate for homogeneous areas of the frame and a small one may be beneficial for motion detailed areas.Analysis shows that,for image sequences with particular characteristics,Region-of-Interest (ROI) may contain a significant part of areas with high motion detail.This feature can be used in FGS coding in which bit planes of macroblocks with small partition sizes are bit-shifted up prior to encoding in order to give them a higher priority and a higher probability of being included in a truncated bit stream,hence maximizing the quality of the potential ROI in the decoded sequence without the need to determine coordinates of the ROI in advance.关键词：H.264;tree-structured motion compensation;region of interest;fine granularity scalability;selective enhancement2|1030|2更新时间：2025-07-16
- 摘要：As to spaceborne bistatic SAR,a new single-line effective squint range model is presented.Its sufficient condition is given,too.It is compared with three other range models which are second-order model,double-line equal velocity model and double-line double velocity model.The result of comparison in theory and simulation show that the single-line range model is an accurate,valid and simple range model.Because the model have the same form as the monostatic SAR,it can be applied to bistatic SAR imaging processing by monostatic SAR imaging methods.Lastly,the chirp scaling algorithm is used to bistatic SAR imaging based on this model.关键词：effective range model;Spaceborne bistatic SAR;chirp scaling2|896|4更新时间：2025-07-16
- 摘要：DCT-based Watson's imperceptive watermarking model resisted downsampling attack is presented.The downsampling image is obtained by quasi-convoluted downsampling and the region,the length and the strength of watermark sequence is adaptively embedded in the downsampling image by exploiting the luminance characteristic and a perceptual distortion constraint,which greatly improves the perceptual quality and robustness of up-sampling watermarked image.Simulation results show that the proposed method can achieve a better robustness to the white noise and video downsampling and the original image is not required for watermark detection.关键词：DCT-based downsampling;video watermarking;imperceptive model;insertion-adaptive;correlation detection.2|784|2更新时间：2025-07-16
- 摘要：Space-time adaptive processing (STAP) technique that is well-known in the area of airborne radars requires very high computing power.In order to meet the real-time requirements in STAP applications,Multi-DSP system is used.In this paper,a method is presented to design parallel algorithms of partially adaptive STAP approaches.Data remapping is used between successive computation steps of STAP.Task level parallelism is used for these steps.As an example,the method is applied to Element space post-Doppler STAP approaches.We also implemented the parallel STAP algorithm on a Multi-DSP system.The effectiveness of our implementation is demonstrated with experimental results.The STAP algorithm is highly signal processing oriented and hence executes efficiently on DSP-based systems.关键词：STAP;parallel processing;DSP2|876|1更新时间：2025-07-16
- 摘要：Characteristic variables-Physical boundary(CV-PB) matching condition is proposed for the interfaces which separate two subdomains with different materials in multidomain PSTD,and interface field update relations are obtained in the 3-D generalized curvilinear coordinates.Some numerical examples are used to compare the CV-PB with the traditional matching condition.The numerical results show that the proposed matching condition is more stable and accurate than the traditional matching condition.关键词：multidomain pseudospectral time-domain(MPSTD);matching condition for interfaces of subdomains;characteristic variables-Physical boundary(CV-PB)2|887|4更新时间：2025-07-16
- 摘要：This paper describes a new antenna to realize the directional radiation of high-power microwave-helical array antenna fed from double-layer radial waveguide.The feed wire of each helix is connected with an H-coupled probe inserted into a radial waveguide,and excited by a TEM wave between the two parallel plates of the waveguide.Helices and probes are arranged on the upper plate to form a circular array.This antenna accepts directly an azimuthally symmetric output of a HPM source and radiates a high-gain pattern with a boresight peak.The use of H-coupled probes makes the array antenna compatible with the intense electric fields associated with high-power microwave sources.In addition,the array antenna has a simple structure and can project circular polarized electric field.In this paper,the fundamental theory of function is presented;an array antenna for a frequency band of 3.8GHz to 4.2GHz is designed and simulated.At 4.0GHz,the calculated aperture efficiency shows a high value of 72.3% and the axial ratio value at the normal direction is of 1.55.In the range of 3.8GHz to 4.2GHz,the aperture efficiency is over 69% and the axial ratio is below 1.7.关键词：helical antenna;radial waveguide;array antenna;H-couple probe;high-power microwave2|1870|26更新时间：2025-07-16
- 摘要：Radial acceleration of radar and target is a important character of the relative movement of them and can enhances maneuvering target tracking and target identification,so study on radial acceleration estimation directly from radar echo is needed.The algorithm of estimating radical acceleration is derived,estimation flow is provided,and the impact of observation interval on radial acceleration resolution is analyzed.Then simulation is carried out and results verify its efficiency.关键词：radial acceleration;radar echo;Wigner-Hough transform;estimation2|1140|18更新时间：2025-07-16
- 摘要：Wigner-Ville distributions are implemented for a multicomponent linear frequency modulation (LFM) signal,a single component nonlinear frequency modulation (NLFM) signal,and a multicomponent NLFM signal.Different characteristics between signal items and crossed items are discussed.A concept of midpoint set of time-frequency curves is presented.A general law for crossed item appearing is studied.In time-frequency plane,the images of signal items are smooth continuous curves,but the images of crossed items are pinto interference patter ns.For a multicomponent signal,crossed items appear in midpoint set of the signal time-frequency curves.A single component NLFM signal can also produce crossed item,and it appears in self-midpoint set of the signal time-frequency curve itself.关键词：Wigner-Ville distribution;time-varying signals;time-frequency analysis;crossed items;midpoint set of time-frequency curves2|1322|16更新时间：2025-07-16
- 摘要：This paper presents an important characteristic for the bistatic radar clutter spectrum,which is named backside effect.In such an effect,the range-dependent clutter spectra can be easily aligned,and space-time adaptive processing (STAP) is to be more applicable and effective for the ground moving target indication (GMTI) in bistatic systems.Based on backside effect,the spectrum aligning—Angle-Doppler compensation (ADC) is progressed by additional rotation,i.e.ADCR,and this new spectrum aligning method is proved to gain a further performance improvement on GMTI by experiments.关键词：bistatic airborne radar;ground clutter spectrum;backside effect;space-time adaptive processing;ground moving target indication2|1005|1更新时间：2025-07-16
- 摘要：To improve video coder performance and reduce power consumption,a method is proposed to shorten data lifetimes and decrease memory requirement.Memory needs and memory access times are reduced by computing intermediate results by stages and decreasing temporary results storage.We propose an algorithm to reduce the complexity of variable length code output by exploiting register width and shift ability of barrel shifter.Experimental results show that it can lessen the time of variable length code output in video encoders.关键词：memory;video coder;variable length code2|846|0更新时间：2025-07-16
- 摘要：Abstract:In this paper,a novel general design method of quasi-orthogonal space-time block codes for four antennae is presented.Comparison with the design method offered by Jafarkhani,this method enlarges the number of quasi-orthogonal space-time block codes.The performance of these codes is also analyzed.The simulation results show that the performance of the codes designed by this method is similar to or better than that of the codes offered by Jafarkhani.关键词：space-time coding;space-time block coding;quasi-orthogonal design2|1060|2更新时间：2025-07-16
- 摘要：A domain decomposition method (DDM) using element combination technique is developed for solving electromagnetic scattering problems.Instead of communicating information through virtual boundary conditions just as the traditional DDM,the presented method maps the internal fields in each sub-domain onto the interface nodes,which results in a reduced matrix equation.The whole domain solution would be obtained trivially once the fields on the interface nodes are solved.Therefore the computational efficiency would be greatly improved and memory requirement is decreased dramatically.This method is very efficient for optimization problems,such as radar cross section optimization.The validity and computational efficiency have been verified by numerical examples.关键词：domain decomposition method;element combination technique;electromagnetic scattering;radar cross section optimization;finite element method2|697|0更新时间：2025-07-16
- 摘要：With the exploration and exploitation of wavelength-division multiplexing (WDM) technology,the diversification of traffics in networks has accelerated the application and development of multicast technology.Due to the big difference between wavelength bandwidth and the traffic requirement between each pair of nodes,it is necessary to groom the traffics in the network to reduce the resource usage and costs of networks.But the algorithms of traffic grooming become more complex with the appearance of multicast.This paper proposes a heuristic algorithm which grooms the static traffics in multicast mesh optical networks efficiently and achieves a good result.关键词：wavelength division multiplexing (WDM);add/drop multiplexer (ADM);multicast optical network;traffic grooming2|947|0更新时间：2025-07-16
- 摘要：For real-time detection of moving object,the general and simple method is based on background image difference.However,it requires the accurate current background image,and so far,no reasonable approach has been designed and implemented for automatic background updating along with the illumination variance,which limits its applications.To overcome the above problem,a new self-adaptive background approximating and updating algorithm based on optical flow theory is first presented in this paper.Moreover,the difference image is obtained by using a color image difference model,and then a self-adaptive thresholding segmentation method for moving object detection based on Gauss model is developed and implemented.Experimental results demonstrate that the proposed new background updating method can update the background exactly and quickly along with the variance of illumination,and the self-adaptive thresholding segmentation method based on Gauss model can extract the moving object regions accurately and completely,which is the foundation for further objects recognition and understanding.关键词：moving object detection;background difference;optical flow;image segmentation;background updating2|1761|17更新时间：2025-07-16
- 摘要：A novel method for non-stationary target detection and direction finding with broad-beam high-frequency(HF) radars based on time-frequency analysis is proposed.Target ridges on the time-frequency representation (TFR) of the echo data are detected,and then array snapshots are formed by sampling the TFR along the ridges,which are finally used to calculate the spatial spectra.Furthermore,the effects on target direction finding due to the cross-range motion of the target are analyzed,and a motion-compensation method is developed,which can effectively estimate the time-variant direction as well as the cross-range velocity of the target.Radar echo signal processing results show the validness of the above methods for the detection and direction finding of non-stationary targets with broad-beam HF radars.关键词：HF radar;time-frequency analysis;direction finding;cross-range velocity2|2117|2更新时间：2025-07-16
- 摘要：Based on combining the generalized likelihood ratio test (GLRT) with antenna selection(AS),the paper presents a non-coherent antenna selection (NON-AS) algorithm over flat Rayleigh fading channel,which do not require channel state information (CSI) for antenna selection and signal detection.The NON-AS algorithm can be applied to receiver of multiple input and multiple output(MIMO) systems,and selection of receive antennas is based on the Frobenius-2 norm of instantaneous received signal vector.Compared with coherent antenna selection,the NON-AS algorithm do not require estimating channel state information,which greatly reduce system complexity.The pair-wise error probability analysis and simulation results show that,under the condition of high SNR,by selecting the set of antennas that observe the largest instantaneous Frobenius-2 norm of received signal vector,the same diversity gain can be achieved as the one obtained by using all the receive antennas.关键词：antenna selection;non-coherence;generalized likelihood ratio test;signal correlation order2|688|0更新时间：2025-07-16
- 摘要：The goal of model selection is to identify the model that generated the data.Goodness of a model is measured using generalizability,which takes two opposite aspects:goodness of fit and model complexity into account.we use generalized KL-divergence defined on the manifold to measure the goodness of fit,and use the conception of curvature from the point of view of differential geometry to explore the intrinsic model complexity that is free of reparametrization;through theoretical analysis,we proved the future residual that is qualified to measure the generalizability can be expressed by using the intrinsic curvature array of model,from which we propose a new model selection criterion KL-divergence and curvature information criterion with very clear and intuitive geometric understanding of model selection.Experimental results reveal its validity.关键词：model selection;generalized Kullback-Leibler divergence;curvature array;solution locus;expected residual2|901|3更新时间：2025-07-16
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