最新刊期
卷 37 ， 期 12 ， 2009
- 摘要：Radar signal fusion imaging is a new parameterized method.It can remarkably improve image resolution.Traditional fusion method based on modified Root-Music is sensitive to noise,and can not pair model poles exactly.Thus this paper extended MEMP (Matrix Enhancement and Matrix Pencil) to the two-dimensional frequencies estimation of spare data,and proposed a novel fusion technique based on Extended Matrix Enhancement and Matrix Pencil (EMEMP) method in order to apply to sparse data fusion.First,combinative enhanced matrix in each dimension is constructed to satisfy pairing requirement of MEMP method.Then model poles are estimated and paired by MEMP method.Once model coefficients are estimated,bandwidth interpolation is implemented to fuse radar data.The experimental results show that new technique can resolve the problem of poles mismatch,and improve stability of parameters estimation relatively to traditional fusion methods.关键词：radar signal fusion imaging;MEMP method;poles pairing;bandwidth interpolation2|965|6更新时间：2025-07-16
- 摘要：The generalized likelihood ratio test detector (GLRTD) for the airborne MIMO radars was studied in the paper.It is well-known that the GLRTD performs poorly in the case of limited secondary data.To settle this problem,the GLRTD with diagonal loading (LGLRTD) was proposed exploiting the low-rank property of MIMO radar clutter subspace and the diagonal loading techniques.The closed-form detection probability and false alarm probability were derived.To reduce the computational load of the proposed detector,a simplified detector was introduced by considering the block-diagonal property of the clutter covariance matrix.Theoretical and simulation results showed that the proposed detectors had CFAR with respect to the covariance matrix of clutter,and were superior to the conventional GLRT detectors.关键词：MIMO radar;diagonal loading;GLRT(generalized likelihood ratio test);CFAR2|1179|4更新时间：2025-07-16
- 摘要：A new method of SAR jamming is proposed:the 2-D cosinusoidal phase-modulated repeater scatter-wave jamming.This jamming takes advantages of both the 2-D cosinusoidal phase-modulated repeater jamming which can form multi-false targets,and the scatter-wave jamming which can make the jamming echo take the real targets' scattering information.The combination complements each other,provides a feasible approach of achieving the multi-false targets jamming and the false targets take the real targets' scattering information,and realizes the vivid multi-false targets jamming in time,frequence and polarization domain.Its feasibility and validity are proved by theoretical analysis and simulation.关键词：SAR;2-D cosinusoidal phase-modulated;repeater jamming;scatter-wave jamming2|1916|14更新时间：2025-07-16
- 摘要：HRRP reflects structure characters of the target, which are valuable for automatic target recognition.In this paper, upon key techniques of ATR for high resolution radar,we research and develop a whole set of real time HRRP ATR system for aircraft,including the ATR algorithms、hardware、target information display technique and radar system integration.The system is aimed at practicality of RATR and proven working well during the practice online radar experiments.关键词：high resolution range profile;recognition system;real time process2|2282|4更新时间：2025-07-16
- 摘要：A contention-based forwarding routing protocol for VANETs in city environments was proposed,which using distributed contention-based strategy to select the next hop based on the positions of the neighbor nodes without HELLO messages.The novel scheme forwards packets along an anchor-based path which is determined according real time traffic information and the topology of the network,with the idea of "carry and forward" to deal with partitioned networks.Simulation result shows that it achieves significant delivery rate improvement and lower delay compared other similar routing approaches.关键词：vehicular ad hoc;routing algorithm;contention-based forwarding2|1230|5更新时间：2025-07-16
- 摘要：The application of the traditional extremum seeking algorithm (ESA) to an extremum seeking system (ESS) with multivalued output function can result in that the output of the controlled plant can’t precisely and smoothly converge to its global extremum.Therefore,a novel ESA based on chaotic annealing recurrent neural network with parameter disturbances (CARNNPD) is proposed for ESS to solve this problem.Utilizing the ergodicity property of chaos and the strategy of parameter disturbances,the coarse search based on chaotic annealing and parameter disturbances will make the output of ESS move to the neighborhood of its global extremum.Then the elaborate search based on recurrent neural network can guarantee the output of ESS precisely and smoothly converge to the global extremum.Moreover,the conditions for asymptotic convergence,solution optimality and global convergence capability of the proposed ESA are derived.Simulation results validate that this design helps to improve the global searching capability of ESA.关键词：recurrent neural networks;annealing;extremum seeking algorithm;parameter disturbances;optimization method2|900|6更新时间：2025-07-16
- 摘要：Together with the nonlinear time series analysis and the giant data samples authorized by CAIDA,the chaotic character of network delay time series indicates that its evolvement process existed chaotic identity.Then,we proposed a revised Logistic model with sine and cosine functions to describe the evolvement state of network delay.Moreover,particle swarm optimization (PSO) algorithm is adopted for the parameters estimation of the revised model,which is evaluated from the perspective of convergence,fitting accuracy and forecast accuracy.The result reviews that the structure of the optimized model is reasonable,and reflects the movement of network delay accurately.关键词：Internet measurement;network delay;Logistic model;PSO2|1173|6更新时间：2025-07-16
- 摘要：Scatterer density dependent generalized likelihood ratio test (SDD-GLRT) performans well in detecting a spatially distributed target in the presence of additive non-Gaussian clutter,where the clutter is modeled as a spherically invariant random vector (SIRV).But SDD-GLRT is a statistically optimum detector,which results in performance loss in the practical case.Base on the order statistics detection theory,a modified SDD-GLRT detector is proposed,which utilizes a priori knowledge of the scatterer spatial distribution fully.It shows that the probability of false alarm is independent of the underlying mixing distribution,the normalized clutter covariance matrix and the steering vector.Hence the modified SDD-GLRT is a constant false alarm rate (CFAR) detector.The experimental results show that the modified SDD-GLRT detection performance is significantly improved by increasing the number of scatterers or the number of pulses used.For detecting a sparsely distributed target,the modified SDD-GLRT outperforms both of the SDD-GLRT and the NSDD-GLRT.Furthermore,the modified SDD-GLRT is more robust for a moderate mismatch of the expected number of scatterers or different spikiness of the clutter.关键词：spherically invariant random vector;range-spread target detection;order statistics;target scatterer;robustness2|1194|21更新时间：2025-07-16
- 摘要：Based on the negative refraction circuit theory,a novel broadband Power Divider and Phase Shifter which is constructed by conventional transmission line with lumped-element series capacitors and shunt inductors is proposed in this paper.And the realization method of broadening impedance and axis ratio bandwidth is analyzed.A microstripe antenna which central frequence is 1.268GHz is designed,and the axis ratio bandwidth achieved 52.37percent.The VSWR is below 2 in the AR bandwidth.关键词：negative refraction;axis ratio bandwidth;power divider;phase shifter2|1136|2更新时间：2025-07-16
- 摘要：The simulation of spatial-temporal correlated K-distribution sea clutter will benefit the research on detection performance of ship boarded radar in the clutter environment.The features of temporal and spatial correlation are analyzed first in this paper.A simulation method based on SIRP for spatial-temporal correlated K-distribution sea clutter was then proposed.Theoretic analysis and simulation are proceeded for the feature of temporal correlation and spatial correlation and amplitude distribution.Results demonstrate that the clutter generated by this method is K-distribution and its spatial-temporal correlation can be set on demand.关键词：K-distribution;SIRP;temporal correlated;spatial correlated2|1396|7更新时间：2025-07-16
- 摘要：Folded waveguide structures are potential compact sources of high-power terahertz radiation.We present feasibility studies of an oscillator,the fundamental theory including dispersion and coupling impedance are given.The geometry at 0.1THz is designed by theory and software,and the structure is simulated with 3D PIC code.The results are presented,a 175 W output power at 0.1THz is observed,the interaction efficiency is over 7%,while an electron beam of voltage 20.6kV,current 0.121A is injected,and the magnetic field is 3000 gauss.关键词：folded waveguide;terahertz;dispersion2|900|9更新时间：2025-07-16
- 摘要：In this paper,a polarimetric super processing method based on ESPRIT is proposed,and the CRB of scattering centers parameters estimation,including position,intensity and coherent phase are derived.Experiments reveal that the performance of the proposed method is very close to CRB.Superiorities of our method relies on the following processing techniques:(1) joint processing of super-resolution and full polarization,which enables extraction of coherent scattering matrix of target;(2) utilization of fully polarized backscattered data,which improves SNR and enhances the performance of estimation;(3) utilization of the rotational invariance property of signal subspace,which greatly reduces computational burden by avoiding multi-dimensional search.Simulation and real data experiments validate its effectiveness.The conclusion is meaningful to polarimetric super-resolution imaging,algorithm evaluation,polarization feature extraction and recognition,and high-resolution polarized radar system design.关键词：super-resolution;2-D ESPRIT(estimation of signal parameters via rotational invariance techniques);full-polarization;Cramer-Rao bound;performance analysis2|1080|1更新时间：2025-07-16
- 摘要：Due to the equivalent phase center error,the imaging quality of the Multiple-Input Multiple-Output synthetic aperture radar (MIMO-SAR) may be degraded with a series of "spurious peaks" in the cross-range direction.Based on a proposed model of MIMO-SAR,this paper derives the analytic expressions for the equivalent phase center error,and its influence on the imaging quality is studied.It is shown that the periodical quadratic phase error is a key factor in the equivalent phase center error,and its compensation may effectively overcome the "spurious peaks".Finally,both theoretical analysis and the numerical experiments are provided to demonstrate the effectiveness of the proposed analysis and compensation methods.关键词：multi-input multi-output (MIMO);synthetic aperture radar (SAR);wide-swath;high-resolution;equivalent phase center2|1494|9更新时间：2025-07-16
- 摘要：For multiple-input multiple-output(MIMO)space-time coded architecture based on distributed antenna system(DAS),signals from different transmit antennas arrive asynchronously to the receiving antennas due to the random channel propagation delays among different links.Consequently,linear detection algorithms may be more complicated because of the complexity of inter-symbol interference.Furthermore,the optimal linear detection algorithm would not be obtained directly by applying minimum mean square error(MMSE)criterion.Focusing on the problem above,this paper supposes the optimal linear detection algorithm,named Joint-MMSE detection,in which maximum ratio combining(MRC)is implemented firstly,subsequently MMSE detection,and finally the diversity order by bounding bit error rate(BER).According to the simulation results,MRC-MMSE is authentically the optimal linear detection algorithm of MIMO with distributed transmit antennas.关键词：distributed antenna system;multiple-input multiple-output;optimal linear detection algorithm;maximum ratio combining;minimum mean square error2|1200|5更新时间：2025-07-16
- 摘要：Traditional K-means arithmetic model is half-baked because of the segmentation of the images is only concerned about feature vectors but ignore the spatial relation between two of the pixels.This paper use Markov random field to describe the neighborhood system of the image pixels.Then the concept of "refusal" is introduced in the K-means arithmetic.Meanwhile,the method of initial cluster number and center is also decided.Therefore the more integrity model of image segment arithmetic based on Markov random field is formed.The arithmetic is validated by experiment later.关键词：K-means cluster;image segmentation;Markov random field;refusal2|2698|5更新时间：2025-07-16
- 摘要：The Programming Language for the Block Cipher Algorithm (PLBCA) is proposed,which is similar to the mathematical description and is adapt to describe the structure of block cipher algorithm in a formal way.The grammar of PLBCA is presented and the DES algorithm is described using PLBCA as an example.The PLBCA parser is implemented by the ANTLR tools.Using PLBCA,the cryptography experts could test and analyze the cryptographic algorithms conveniently and quickly.PLBCA may improve the testing efficiency of cryptographic algorithm,and it can be used as an assistant for the design and automatic analysis for cryptographic algorithms.关键词：domain specific language;programming language for the block cipher algorithm;DES5|1183|2更新时间：2025-07-16
- 摘要：Based on the Laplace Transfer (LT) principle,a novel 3D finite-difference time-domain (FDTD) method,by which the electromagnetic scattering of the dispersive media can be analsized,is proposed.It is called the Current-Density-Laplace-Transfer FDTD (CLT-FDTD) algorithm.According to the constitutive relation equation between the current density vector and electric-field intensity,the constitutive relation of plasma medium is transformed to the s-domain by using the LT principle.Finally based on the inverse LT and the exponential time stepping,the FDTD iteration equations are obtained which is easy to be solved in the time domain. Using this method,the radar scattering cross-sections (RCS) of the non-magnetism and magnetization plasma ball are computed.The results show that this method is correct and efficient.关键词：Laplace transfer;magnetized plasma;electromagnetic scattering;finite-difference time-domain method3|1166|8更新时间：2025-07-16
- 摘要：The analysis of the properties of the threshold in the Otsu segmentation method can provide theoretical help for improving and applying the Otsu method.This paper proves a conclusion that the threshold of the Otsu method is the average of the means of two classes partitioned by this threshold.Thus,when the difference of the two within-class variances is large,the threshold of the Otsu method tends to be closer to the class with larger within-class variance,which means that more pixels of this class will be classified into the another class.To overcome this problem,this paper presents an improved Otsu algorithm by constraining the search range of the ideal segmentation threshold.Experimental results show the superiority of the proposed algorithm by yielding more reasonable segmentation results compared to the traditional Otsu method.关键词：image segmentation;threshold selection;Otsu criterion3|1237|48更新时间：2025-07-16
- 摘要：How to avoid the various undesired hybridizations is a crucial problem in DNA based computing and other microarray applications.In order to achieve reliable hybridization,we should explore reliable and robust encoding methods.The single template method proposed by Arita can achieve a promising shift distance with l/3 between DNA strands.However,the limited codes produced by it cann’t meet the requirement of any practical application because only one possible template is employed.We extend it to multiple templates case so that the final codes can be linearly increased with the number of the templates while still keeping a shift distance close to l/3.Thus,the improved method can be applied to larger applications.关键词：DNA computing;encoding method;template;error correcting code2|1082|4更新时间：2025-07-16
- 摘要：Geosynchronous parasitic SAR system is a kind of bistatic system,which uses a fixed ground-based receiver and a geosynchronous satellite as non-cooperative illuminator transmitting waves like television,FM broadcast or navigation signals.The development of the system will be bright due to its military stealth,long-time supervising and economic advantages.The system has the characteristics of continuous random signal as transmitting signal and the precise positions of the radar unknown,based on which several key technologies for the parasitic system are discussed,including the ranges of pulse repetition time (PRT) and window length that limits transmitting signals,windowed signal full bandwidth and Signal to Clutter Ratios (SCR),the retrieval of the satellite’s daily orbit.Finally,according to the above analysis the geosynchronous parasitic SAR imaging is accomplished by simulations.关键词：geosynchronous satellite;parasitic SAR system;window length;Signal to Clutter Ratios (SCR);retrieval of the satellite’s daily orbit2|1030|2更新时间：2025-07-16
- 摘要：Recently,Chen etc.proposed a novel self-adaptive image encryption algorithm.The analysis shows that it is vulnerable to chosen plaintext attack.Then the original algorithm is revised based on self-adaptive image encryptoin technique.The experiments show that the revised algorithm has better performance on both security and speed than two known algorithms.关键词：cryptography;image encryption;self-adaptive;cryptanalysis16|1213|5更新时间：2025-07-16
- 摘要：A kind of time-vary nonlinear dynamic system is studied in this paper.An effective data fusion state estimation algorithm is presented in time of multiple sensors observing a single target with different sampling rates asynchronously.The asynchronous multirate system is transformed to synchronous multirate system by use of the established multiscale models.In each step,to get the state estimate,state prediction is followed by state update.In state and measurements prediction step,strong tracking filter (STF) is used.While,in state update step,distributed structure with feedback is used,and the fused state estimate is obtained by sequentially use of the measurements observed by different sensors.The augmentation of state or measurement dimensions are avoided by use of the presented method,and the real-time property of the algorithm is guaranteed.Simulation results show the effectiveness of the proposed algorithm.关键词：data fusion;nonlinear system;asynchronous;multirate;strong tracking filter3|1505|3更新时间：2025-07-16
- 摘要：The theory of the micro-Doppler (m-D) effect in frequency-stepped chirp signal is studied,and the causations of the range profile’s migration and wrapping are analyzed.The m-D effects induced by rotation and vibration are discussed in detail and the analytical expressions of the m-D signatures in the range-slow time plane are deduced.The algorithm for extraction of m-D signatures is proposed which is based on the Hough transform and time-frequency analysis.The implementations of the algorithm under condition of different rotating/vibrating frequencies and radii are discussed.Simulations are given to prove the validity of the theoretical analyses and the proposed m-D extraction method.关键词：micro-Doppler;frequency-stepped chirp signal;Hough transform;time-frequency analysis;target recognition2|1579|9更新时间：2025-07-16
- 摘要：This paper presents an improved algorithm for suppressing the synthetic aperture radar image speckle noise,in which the double density dual tree complex wavelet transform (DD-DT CWT) was combined with the bivariate shrinkage function(BSF) with local variance estimation.The SAR image was firstly decomposed by the DD-DT CWT,the bivariate probability density function was used as statistic correlation model for wavelet coefficients and their parent,and the corresponding bivariate shrinkage function was obtained by Bayes' estimation theory.Then the wavelet coefficients were shrunk by the BSF,in which different orientations were nonlinear processed adaptively,finally the denoised image was reconstructed by all the update coefficients.The algorithm presented was tested by simulated and actual SAR image,and compared with other methods.Results are presented to verify that,the new algorithm significantly outperforms the traditional wavelet-transform-based denoising algorithm,and effectively denoises the noisy image as well as preserves the particulars.The performance index of the denoised image were simultaneously improved.关键词：synthetic aperture radar image;double density dual-tree complex wavelet transform;speckle noise suppression2|1897|3更新时间：2025-07-16
- 摘要：Self-healing is the ability with which a routing system can restore or rebuild routes automatically after network failures without impacting on packet forwarding.Although existing intra-domain routing protocols can adapt to network failures somewhat,they can not satisfy user requirements because their convergence time ranges from several seconds to more than one hundred seconds.During the period of self-healing,network routes may be incorrect and even have black hole or loop which will lead to packet loss and impact network applications.In order to solve this problem,several intra-domain self-healing routing solutions have been proposed.After analyzing the problems of current intra-domain self-healing routing,we propose intra-domain self-healing routing model,and divide the solutions into five categories according to the model:weight change,flood restriction,fast reroute,multi-path and local reroute.Based on the analysis of some typical solutions in each category,we compared the features of these solutions and studied the availability of the solutions in detail.Finally,we discussed several key issues for further study.关键词：intra-domain routing;self-healing routing;network failure2|1208|7更新时间：2025-07-16
- 摘要：This paper describes transport properties of two dimensional electron gases in antiparallel magnetic-electric barrier structure.By means of transfer matrix method,we obtain the explicit expressions of electron transmission probability and conductance for a magnetic-electric barrier structure and discuss the influence of different values of the electric potential barrier height on them.The results indicate that this system does not possess any spin filtering and spin polarization and electron gases can realize perfect resonant tunneling and wave-vector filtering.关键词：magnetic-electric barrier;Resonant tunneling;wave-vector filtering;transmission;conductance2|874|0更新时间：2025-07-16
- 摘要：Based on negative refraction circuit mode,A novel broadband analogy-helix antenna feeding by 50 ohm coaxial-line is proposed in this paper,Which is constructed by two layer substrates and six resonance cells being printed on it.Compared to helix antenna,the construction method is more convenience.Measured and simulation results shows that the bandwidth can achieve 30percent,three radiation modes of helix antenna appeared in the bandwidth,and the maximum gain can achieve 5dB.关键词：negative refraction;analogy-helix;radiation mode2|927|0更新时间：2025-07-16
- 摘要：To improve the accuracy of temperature measurement using a CCD camera,the common used method is to build a filtering system in optical path. The method,however,is unsuitable for real industrial measurement because of the complexity of building and adjusting the filtering device,and meanwhile,image matching needs to be considered for obtaining accurate grayscale ratio.To be convenient for industrial temperature measurement,a digital filtering method is proposed based on an algorithm of CCD spectral response curve tracing.The method is compared with conventional method of loading filtering devices.The result indicates that the digital filtering is more convenient for temperature field measurement and keeps a satisfactory accuracy.关键词：temperature measurement;CCD spectral response;curve tracing;digital filtering2|1066|6更新时间：2025-07-16
- 摘要：Portable HF surface wave radar system OSMAR-S adopts Freguency Modulated Interrupted Continuous Waveform (FMICW) and Orthogonal Loop/Whip Antenna Arrays.OSMAR-S obtians surface vector currents by composeing two station surface radical currents.Verification tests of OSMAR-S system against in situ measurements had been accomplished on Nov.12~17,2007.A observing method of fixed five-point and a movable point simultaneity comparison was used in the test.This paper introduces the system structure of OSMAR-S system,and then presents comparison results of surface currents measurements.The results indicate the OSMAR-S system is meet the need of design.关键词：portable HF ground wave radar system;sea surface current;compared to measuring;correlation coefficie2|1282|13更新时间：2025-07-16
- 摘要：We report a method for designing self-equalized dual-passband filters by using complex transmission zeros.The filter is realized by utilizing open-loop microstrip resonators.Using full-wave EM software,a 12-pole high-temperature-superconducting (HTS) filter which has two self-equalized passbands is designed.The two passbands (2.631~2.679GHz and 2.781~2.829GHz) are separated by a stopband (2.681~2.779GHz).The result indicates that the flat group delay is over 60 percent of the passbands.关键词：dual passband;self equalized;HTS;microstrip filter;coupling matrix2|1348|4更新时间：2025-07-16
- 摘要：With the variations of circuit parameters,the operating state of current mode controlled buck converter by utilizing compensating ramp current can shift between stable period-one region,robust chaos region in continuous conduction mode (CCM) and intermittent chaos region in discontinuous conduction mode (DCM).By establishing the piecewise smooth iterative map with ramp compensation,two borderline equations of the orbit states shifting of current mode controlled buck converter are derived,and the corresponding operating state regions are decided.The simulation results of the parameter space map of buck converter verify the estimated operating state regions by two borderline equations.The estimation of operating state regions for switching converter has practical guideline signification for selection of circuit parameters as well as stability control of chaos.关键词：buck converter;ramp compensation;iterative map;borderline equation;operating state region2|1001|9更新时间：2025-07-16
- 摘要：The template storage and transmission security are crucial for biometrics-based authentication.Bases on the low storage demand and training cost of VQ-based (Vector-Quantization) voiceprint authentication,a MRP-based (Multispace-Random-Projection) cancelable voiceprint template was proposed in this paper.The performance consistency was investigated by the invariableness of the quantization error.The security of the proposal was clarified by the characteristics of the random matrix and the underdetermined system.The experimental results demonstrated the validity of the proposal.关键词：biometric-based authentication;cancelable template;random projection2|1075|4更新时间：2025-07-16
- 摘要：Based on equivalence matrix and joint decision matrix,the reason of the existing algorithms inefficiency for rules extraction in massive data set is analyzed.The method of rules extraction and calculating process with serial carry chain based on the arbitrary division are presented.This process about the rules extraction will be changed into many agent (sub-systems) and inter-agent to share data by the "Parallel plus Serial" rule calculation,which can effectively improve the algorithm on the massive data set.Complexity analysis shows that the algorithm is more efficient than those existing algorithms.An example is used to illustrate the efficiency of the new algorithm.At last,experimental result shows that the calculating process with serial carry chain for rules extraction is not only efficient but also scalable.关键词：rough sets theory;serial carry chain;agent;matrix block;joint decision matrix2|788|0更新时间：2025-07-16
- 摘要：By exploiting multiple transmissions of orthogonal coding signal and single reception,a new GMTI processing scheme for ground moving targets detection with low velocity in space-borne multiple input and single output (MISO) radar systems is presented in the paper.Firstly,the requirements of multiple orthogonal coding waveform for the MISO radar system is analysed in detail. Focusing on this new scheme,an orthogonal waveform optimization design method is also proposed.In this GMTI processing scheme,different satellites independently transmit the optimized orthogonal waveform and one of the transmission satellites acts as the receiver and matches the received echo signal with each of the transmission signal,respectively.Detection of ground moving targets with low velocity can be achieved by joint adaptive two-dimension processing of multi-channel and multi-pixel on image domain.In this way,data communications among multiple satellites is not necessary and hence real time processing capability of the whole system can be improved.The performance of one-dimension image after matching by the receiving satellite,i.e.the shape of its mainlobe and the performance of its sidelobe is considered as the optimization criteria in the proposed waveform design method.Simulations and analysis are performed to testify the feasibility and effectiveness of the proposed system and waveform design method,in terms of the orthogonality of waveform,convergence of the design algorithm,clutter cancellation,and detection performance of targets.关键词：sparse space-borne radar;ground moving target identification;MISO;waveform optimal design2|994|2更新时间：2025-07-16
- 摘要：This paper proposed a new overall adaptive algorithm which fuses IMM(Interactive Multiple Model) and IE (Input Estimation) for maneuvering target tracking.The tracking performance of IE is improved significantly through modification of innovation sequence.After analyzing the characteristic of MIE(Modified IE) algorithm,two MIE subfilters with different detection window length are adopted in IMM filter to keep overall self-adaptive tracking of different maneuvering level.Simulation results have revealed better performance characteristics of the proposed algorithm in comparison with traditional IMM which adopts CV-CA models.关键词：interactive multiple model;maneuvering target tracking;input estimation;innovation sequence2|902|7更新时间：2025-07-16
- 摘要：Searching for robust Pareto optimal solutions is one of the most important fields in the research of multi-objective evolutionary algorithm (MOEA).Recently,both traditional MOEA and EFF-MOEA which optimize "original objective function" and "effective objective function" respectively easily lose some kinds of solutions.In order to solve this deficiency,we defined a new robust Pareto optimal solution and proposed a novel MOEA named as MOEA/R,which converts a multi-objective robust optimization problem (MROP) into a bi-objective optimization problem.Each of the two objectives represents a sub-MOP,one optimizes solution’s quality and the other optimizes solution’s robustness.Through the comparison and analysis between MOEA/R,NSGA-Ⅱ and Eff-MOEA,the experimental results demonstrate that MOEA/R can acquire good purposes.The most important contribution of this paper is that MOEA/R explores a novel methodology for searching robust Pareto optimal solutions.关键词：MOEA;robustness;quality;robust Pareto optimal solutions;effective objective function2|1211|6更新时间：2025-07-16
- 摘要：An integrated method of acoustic signal detection and direction-of-arrival (DOA) estimation is proposed.As exploiting the beam-spectra envelop (BE) knowledge of the spatial spectrum outputted by beam scanning system,it is named as BE method,in which,based on the results of energy detection,the 3dB-width information of spectral peaks is used further to detect the source number in each peak,and the DOAs are estimated by 2-D Capon searching.The Qiandao Lake experimental results show that,comparing with traditional algorithms,the performance of target detection and DOA estimation is improved at lower SNRs.关键词：multi-target detection;source number estimation;high resolution;direction-of-arrival estimation;acoustic signal processing2|1105|1更新时间：2025-07-16
- 摘要：A novel dual frequency and dual circular polarization multilayer microstrip antenna for satellite communication is presented.The proposed antenna can realize right circularly polarized radiation and left circularly polarized radiation simultaneously at 420±1.5MHz and 450MHz±1.5MH by using the Lange-coupler as an orthogonal feeding network.And,the duplex communication is achieved for the single antenna.The patch coupled feeding and additional lumped filtering network improve isolation effectively.In addition,the antenna is constructed with high permittivity dielectric substrate,which can help to reduce the antenna size.The Lange-coupler size is miniaturized (about 74.6%) with the meander-line structure.A good agreement is achieved between the simulation and the experiment results.In the operating frequency band,the isolation is more than 40dB,VSWR is less than 2.0 and the radiation gain of the proposed antenna is larger than 3dBc.The measured results show that both of the 3 dB axial ratio and the 0 dB gain width reach up to 80 degrees.关键词：high isolation;lange-coupler;coupled feeding;dual circular polarization;microstrip antenna2|1951|2更新时间：2025-07-16
- 摘要：The fluctuant peculiarities of a signal passing through rain are studied by the theory of waves propagating through a random media.The detailed formulae are deduced for single-wave channel and two-wave channel.The methods evaluating the effects on Rayleigh fading distribution model and Rician fading distribution model induced by rain scattering are discussed.The methods used in this paper is effective for studying the impacts of meteorological scattering environment (snow,dust-storm,etc.) on the envelope probability density functions in multi-path channels.关键词：rain;multi-path channels;probability density functions2|1814|1更新时间：2025-07-16
- 摘要：A new algorithm has been presented to estimate the direction-of-arrival (DOA) in the presence of coherent signals.The conception of C-SPRIT has been used in our algorithm.By forming special data matrix,our algorithm performs well in estimation of DOA,no matter there are coherent signals or not.The DOA estimation of coherent signals has been mitigated by conventional spatial smoothing using the divided sub arrays.However,this result is obtained at the cost of losing effective spatial aperture,and the detectable number of coherent signals is 2N/3 at most (N is the number of array sensors).Compared with spatial smoothing method,our algorithm not only improves the estimation accuracy but also can detect N-1 coherent signals without aperture loss.The de-correlation of coherent signals is completely solved.The computational load is reduced by using the numerical algorithms of ESPRIT without spectral peak search.Computer simulation results are provided to verify the validity and superiority.关键词：conjugate ESPRIT(C-SPRIT);forward/backward spatial smoothing;coherent sources;direction-of-arrival (DOA);ESPRIT;data matrix reconstruction.2|1064|2更新时间：2025-07-16
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