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116 results about "Fourth order cumulants" patented technology
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Rapid positioning method of binary TDOA/FDOA satellite-to-earth integration positioning system
InactiveCN102331581AFast positioning convergence speedAdaptableSatellite radio beaconingSignal-to-noise ratio (imaging)FDOA
The invention relates to a rapid positioning method of a binary TDOA / FDOA satellite-to-earth integration positioning system. According to the invention, problems that exist during accurate estimation of a TDOA / FDOA and rapid positioning in a binary positioning system can be solved. The method comprises the following steps that: a binary TDOA / FDOA positioning model is constructed; and a real-time combination estimation is carried out on a TDOA and an FDOA through a fourth order cumulant two dimensional separation parameter estimation method; object location is carried out through an IMM-UKF filtering method; and then, a relationship between a positioning precision and a signal to noise ratio of a receiving signal is analyzed; at last, a situation of an influence of all factors on a positioning error is analyzed. According to the invention, a complete and trusted assessment can be carried out on a positioning system; there is no requirement on a type of a signal that is emitted by a ground radiation source and thus the rapid positioning method has a strong adaptability and a wide application range; moreover, the method has good anti-noise and anti-interference capabilities; and a positioning convergence rate is high and a high positioning precision can be reached. Therefore, the invention has a high practical application value.
Owner:HARBIN INST OF TECH
Multi-objective near-and-far field mixed source positioning method
ActiveCN105589056AReduce usageReduce computational complexityPosition fixationSensor arrayComputation complexity
The invention provides a multi-target near-and-far field mixed source positioning method and belongs to the field of the array signal processing technology. According to the method, firstly, a symmetric and homogeneous linear sensor array is arranged to receive a target signal, and then the observation signal form of a near-and-far field mixed source is determined. Secondly, a special third-order cyclic matrix is constructed based on the output of a properly selected sensor, and a direction matrix thereof only contains the azimuth information of a far-field source and the azimuth information of a near-field source. Thirdly, the eigenvalue of the third-order cyclic matrix is decomposed, so that a corresponding noise sub-space is obtained. Fourthly, a cyclic autocorrelation matrix based on the observation data of the entire matrix is calculated, and the eigenvalue of the cyclic autocorrelation matrix is decomposed. In this way, a corresponding noise sub-space is obtained. Fifthly, an already estimated azimuth is substituted to the two-dimensional MUSIC spectrum peak searching process, so that the estimation on the distance of the near-field source is realized. The application of four-order cumulants is avoided, and the calculation complexity of the algorithm is effectively reduced. The operation time of the algorithm is shortened. Meanwhile, the cyclic steady interference and the steady background noise are effectively suppressed. Moreover, the extra parameter matching process is avoided.
Owner:JILIN UNIV
Four-order cumulant sparse representation-based MIMO (multiple-input-multiple-output) radar direction of arrival estimation method under mutual coupling condition
InactiveCN105974366ASuppress color noiseImprove angular resolutionWave based measurement systemsRadar systemsMultiple input
The invention belongs to the monostatic MIMO (multiple-input-multiple-output) radar system technical field and relates to a four-order cumulant sparse representation-based MIMO (multiple-input-multiple-output) radar direction of arrival estimation method under a mutual coupling condition. The method of the invention comprises the following steps that: a transmitting array transmits mutually-orthogonal phase encoding signals, a receiving end carries out matched filtering on the phase encoding signals so as to obtain receiving data, and the influence of unknown mutual coupling is eliminated through linear transform based on the strap-shaped symmetric Toeplitz structures of the mutual coupling matrixes of the transmitting array and the receiving array; and a dimension reduction conversion matrix is constructed to carry out dimension reduction processing on mutual coupling-eliminated data, and a four-order cumulant matrix of a special form is constructed based on a new data matrix. According to the method of the invention, since the four-order cumulant technique and a weighted sparse representation framework are adopted, colored noises are successfully inhibited. The method of the invention can achieve accurate direction of arrival estimation under a Gaussian color noise condition, and has higher angular resolution and better angle estimation performance.
Owner:HARBIN ENG UNIV
Quick beamforming method capable of improving array resolution and gain
InactiveCN101609150AImprove resolutionOvercoming demandsAcoustic wave reradiationComputation complexityComputation process
Owner:HARBIN ENG UNIV
Method for separating vibration signal blind sources under strong noise environment
ActiveCN101729157AReduce the impactAchieve separationTransmitter/receiver shaping networksTransmission noise suppressionSignal onTime delays
The invention discloses an algorithm for separating vibration signal blind sources under a strong noise environment. The method comprises the following steps: 1, de-noising a group of given mixed signals containing noise through a time delay autocorrelation method to acquire de-noised mixed signals; 2, performing mean value removal and steady whitening pretreatment on the mixed signals acquired in the first step to further reduce the influence of the noise signals on the separation result; and 3, calculating second-order and fourth-order cumulated amount of the initial separate signals, using the sum of diagonal elements of second-order and fourth-order cumulated amount matrixes as a cost function, and maximizing the cost function to similarly diagonalize the joints of the cumulated amount matrixes so as to realize the separation of the signals of the independent sources and acquire orthogonal separation matrixes. The method combines the conventional de-noising method and the blind separation algorithm to realize the separation of the mixed signals under the strong noise environment, and has the advantages of good separation effect, high convergence rate and de-noising effect free from the limitation of the set threshold value compared with the conventional algorithm.
Owner:NANJING UNIV OF AERONAUTICS & ASTRONAUTICS
Space time block coding (STBC) MC-CDMA (Multicarrier Code Division Multiple Access) signal blind identification method based on cyclostationarity
ActiveCN104393963AEasy to identifyEfficient identificationReceiver specific arrangementsError prevention/detection by diversity receptionCdma signalPhysical model
The invention claims to protect a space time block coding (STBC) MC-CDMA (Multicarrier Code Division Multiple Access) signal blind identification method based on the cyclostationarity, and belongs to the technical field of signal processing. The method comprises the following steps: establishing a selection standard of signal correlation functions according to the baseband physical model, signal construction and matrix representation of an STBC MC-CDMA system, and estimating corresponding fourth-order cumulants of the correlation functions; combining a fourth-order cyclic cumulant with the parameter of a channel to establish a cyclic statistic; and extracting a detection threshold according to the detection of cycle frequency, and making a judgment by comparing the detection threshold with the cyclic statistic to realize identification. As indicated by computer simulation, STBCMC-CDMA signals can be effectively identified with low complexity by adopting an algorithm adopted in the invention, and working under the condition of low input signal to noise ratio is feasible. Meanwhile, compared with a conventional identification algorithm, the algorithm adopted in the invention has the advantage that the influence of random noise is reduced by using the advantage of the fourth-order cyclic cumulant, so that the system performance is improved.
Owner:CHONGQING UNIV OF POSTS & TELECOMM
Mono-static MIMO radar distribution type target angle estimation method based on fourth-order cumulant
ActiveCN103926573AImprove estimation accuracyLarge apertureWave based measurement systemsSignal classificationDecomposition
The invention provides a mono-static MIMO radar distribution type target angle estimation method based on a fourth-order cumulant. M transmit-receive antenna arrays are provided, a transmitting end transmits mutually orthogonal phase-coded signals, and a receiving end receives mutually orthogonal phase-coded signals. A matching filter of each receiving array of the receiving end carries out matching filtering on the received orthogonal signals and then carries out separation, and a distribution type target receive signal matrix is obtained. A fourth-order cumulant matrix of the receive signals is calculated by using the distribution type target receive signal matrix. Eigenvalue decomposition is carried out on the fourth-order cumulant matrix, a mutually orthogonal signal subspace and a noise subspace are obtained, and a spatial spectrum function is constructed by using a multi-signal classification algorithm. The distribution type target angle is calculated through a two-dimensional spectral peak searching method. Even when in a colored-noise environment, the mono-static MIMO radar distribution type target angle estimation method based on the fourth-order cumulan still has high estimation accuracy for a central direction-of-arrival angle, can estimate an expansion angle of a distribution type target, and achieves automatic matching between the direction-of-arrival angle and the expansion angle.
Owner:HARBIN ENG UNIV
Ultrasonic receiving array orientation method for transformer partial discharge positioning
InactiveCN103995221ASmall apertureEasy to handleTesting dielectric strengthSorting algorithmTransformer
The invention discloses an ultrasonic receiving array orientation method for transformer partial discharge positioning. According to the method, an ultrasonic receiving array which is arranged along the array edge or the center line of a planar array and is in an L shape or in a cross shape is used. The method comprises the steps that broadband focusing and array expansion are combined, focusing operation is conducted on an ultrasonic array receiving signal of a broadband first, a broadband ultrasonic signal generated through partial discharge is segmented according to time, a focusing matrix is calculated through noiseless data, and the signal is focused on the same frequency band; then, virtual expansion is conducted on the array through a fourth order cumulant algorithm, and a data covariance matrix of the array after virtual expansion is replaced by an unexpanded fourth order cumulant matrix which is formed in sequence of an original array; at last, the partial discharge incoming wave direction of the array after virtual expansion is estimated through a multi-signal sorting algorithm.
Owner:XI AN JIAOTONG UNIV
Nested array direction-of-arrival angle estimation method based on fourth-order cumulants
ActiveCN106019215AIncrease the number of identifiable sourcesOvercome the disadvantage that the number of signals is lower than the number of array elementsRadio wave direction/deviation determination systemsEstimation methodsNested arrays
The invention discloses a nested array direction-of-arrival angle estimation method based on fourth-order cumulants, and mainly aims to solve the problem that the utilization rate of array elements is low and only a small number of signals are identified in the prior art. The method is implemented by the steps as follows: (1) building a one-layer nested array and a two-layer nested array; (2) acquiring the output signal of the one-layer nested array and the output signal of the two-layer nested array; (3) calculating all fourth-order cumulants according to the output signal of the one-layer nested array and the output signal of the two-layer nested array; (4) constructing a fourth-order cumulant matrix according to all the fourth-order cumulants; (5) calculating the noise subspace of the fourth-order cumulant matrix; (6) calculating the space spectrum according to the noise subspace of the fourth-order cumulant matrix and an array manifold matrix; and (7) drawing an amplitude spectrogram according to the space spectrum to get the direction-of-arrival angle. The number of signal sources identified by an array is increased greatly under a limited number of array elements. The method is suitable for target reconnaissance and passive location.
Owner:XIDIAN UNIV
High-order cumulant based bistatic MIMO (Multiple Input Multiple Output) radar parameter estimation method
InactiveCN104330783AReduce operational complexityReduce computational complexityWave based measurement systemsSingular value decompositionArray element
The invention discloses a high-order cumulant based bistatic MIMO (Multiple Input Multiple Output) radar parameter estimation method. A joint estimation method of DOD (Direction of Departure), DOA (Direction of Arrival) and Doppler frequency of targets under a gauss color noise background is given out according to bistatic MIMO radar echo signal characteristics through a characteristic that high-order cumulant is insensitive to gauss color noise. The high-order cumulant based bistatic MIMO radar parameter estimation method comprises constructing two opposite angle section matrixes of cross-fourth-order cumulant of output signals of adjacent matched filters through airspace and time domain information of the bistatic MIMO radar; decomposing a singular value of the opposite angle section matrixes of the four-order cumulant, estimating the number of targets, reducing dimensions through eigenvalues and eigenvectors and constructing a new matrix; obtaining joint estimation of the Doppler frequency, the DOD and the DOA of the targets through the eigenvalues and eigenvectors of the novel matrix. According to the high-order cumulant based bistatic MIMO radar parameter estimation method which is an effective bistatic MIMO radar parameter estimation method, a target parameter estimation process has no specific requirements for the number of transmission array elements and receiving array elements.
Owner:HOHAI UNIV
Direction-of-arrival (DOA) angle estimation method based on dual-layer nested array
ActiveCN106443574AIncrease profitIncrease the number of sourcesDirection findersComplex mathematical operationsSparse constraintEstimation methods
The invention discloses a direction-of-arrival (DOA) angle estimation method based on a dual-layer nested array and mainly aims at solving the problems of heavy computation, low quantity of identified information sources and great estimation error in the prior art. The DOA angle estimation method comprises the following implementation steps: firstly, respectively constructing a first-layer nested array and a second-layer nested array; secondly, acquiring an output signal of the first-layer nested array and an output signal of the second-layer nested array; thirdly, calculating all fourth-order cumulants according to the output signal of the first-layer nested array and the output signal of the second-layer nested array to form a fourth-order cumulant vector; fourthly, constructing an over-complete base according to the fourth-order cumulant vector, and defining an airspace sparse vector; fifthly, converting detection of an airspace DOA angle estimation into solving of a sparse constraint equation; sixthly, obtaining a most sparse solution of the airspace sparse vector by using a convex optimization method; seventhly, drawing an amplitude spectrum according to the most sparse solution to obtain the DOA angle. According to the DOA angle estimation method disclosed by the invention, the quantity of information sources which can be identified is greatly increased under the condition of limited array element quantity; the DOA angle estimation method can be used for target reconnaissance and passive location.
Owner:XIDIAN UNIV
Hybrid matrix recognition method in underdetermined blind source separation based on tensor regular decomposition
ActiveCN104375976ASolving recognition problemsOvercome the disadvantages of difficulty in extracting self-sourced time-frequency pointsSpeech analysisComplex mathematical operationsDecompositionAlgorithm
The invention discloses a hybrid matrix recognition method in underdetermined blind source separation based on tensor regular decomposition. The method mainly solves the problem that in the prior art, hybrid matrix estimation is limited by specific conditions. The method includes the implementation steps that (1), source signals are sampled and observation data are acquired; (2), four-order covariance matrixes in different time delays are calculated through four-order cumulants of the observation data; (3), the four-order covariance matrix in different time delays are expanded into a three-order tensor mode; (4), tensor regular decomposition is conducted on three-order tensors, and a Khatri-Rao product matrix of a hybrid matrix to be recognized is acquired; (5), the product matrix is processed through an eigenvalue decomposition method, and an estimated value of the hybrid matrix is acquired. The method has the advantage of being high in recognition accuracy and can be used in the fields of voice, communication, radar and biomedicine and used for underdetermined blind source separation under the time-frequency aliasing condition.
Owner:XIDIAN UNIV
Method and device for extracting hybrid-phase seismic wavelets
The embodiment of the invention provides a method and device for extracting hybrid-phase seismic wavelets, wherein the method comprises the following steps of: calculating fourth-order cumulants of seismic data; smoothing the fourth-order cumulants of the seismic data by using three-dimensional hysteretic window functions and estimating three spectrums of the seismic wavelets; and extracting the hybrid-phase seismic wavelets by using the three spectrums of the seismic wavelets. With the embodiment of the invention, the estimation precisions of high-order spectrums and wavelets can be improved.
Owner:BC P INC CHINA NAT PETROLEUM CORP +1
Apparatus and method for classifying modulations in multipath environments
ActiveUS20100098193A1Reduce decreaseAmplitude demodulation by homodyne/synchrodyne circuitsModulation type identificationEngineeringMulti carrier
A receiver supports a single carrier (SC) form of modulation and a multi-carrier form of modulation such as orthogonal frequency division multiplexing (OFDM). Upon receiving a signal, the receiver determines a maximum fluctuation range (MFR) as a function of at least a fourth-order cumulant of a received signal; and classifies a modulation type of the received signal as a function of the determined maximum fluctuation range. After determining the modulation type of the received signal, the receiver switches to that modulation mode to recover data from the received signal.
Owner:INTERDIGITAL MADISON PATENT HLDG
Arrival direction estimation method based on conjugation expansion
ActiveCN102694588ALower requirementIncreased number of signal directionsSpatial transmit diversitySignal onEstimation methods
The invention discloses an arrival direction estimation method based on conjugation expansion. The method comprises the following steps of: firstly calculating and receiving a second order statistic between signals, obtaining a conjugation matrix of an oriented matrix by utilizing the property of a delay self-correlation function, then constructing a new pseudo snapshot matrix by utilizing delay sampling of an extensible vector, and finally estimating an arrival direction of a signal on the matrix by adopting a fourth-order cumulant method. By virtue of a signal arrival direction estimation method based on array extension, the number of estimated signal arrival directions is greatly increased and signal arrival direction estimation accuracy can be improved.
Owner:SOUTH CHINA NORMAL UNIVERSITY
Multiple source (Direction of arrival) DOA estimation method
InactiveCN108375751AImprove information utilizationHigh-resolutionRadio wave direction/deviation determination systemsObservational errorFeature vector
The invention belongs to the radio signal positioning technical field, and especially relates to a multiple source (Direction of arrival) DOA estimation method comprising the following steps: obtaining an array reception antenna signal output vector, and building a four-order cumulant matrix according to the signal output vector; carrying out extraction smoothing for the four-order cumulant matrixso as to obtain a new four-order cumulant matrix; decomposing characteristic constants of the new four-order cumulant matrix so as to obtain characteristic vectors corresponding to a noise subspace and a signal subspace; building a space spectrum function according to the characteristic vector of the noise subspace; returning , and increasing multi-snapshot numbers so as to obtain the space spectrum function corresponding to the snapshot number; smoothing the space spectrum function corresponding to each snapshot number; determining the DOA of a space signal source via peak spectrum searching. The method builds the four-order cumulant matrix, reduces the matrix dimensions, reduces operand, carries out multi-snapshot space spectrum function smooth calculation, thus realizing more signal DOA estimation, and reducing influences on space spectrum estimation by the measuring errors.
Owner:PLA STRATEGIC SUPPORT FORCE INFORMATION ENG UNIV PLA SSF IEU
Mine multimode wireless signal accurate identification method
InactiveCN110798275ASolve the problem of low recognition rate under low signal-to-noise ratioRealize classification recognitionModulation type identificationTransmission monitoringAlgorithmSvm classifier
The invention belongs to the technical field of signal identification, and discloses a mine multimode wireless signal accurate identification method. The method includes: mine communication signal identification: signal preprocessing, characteristic parameter extraction and signal identification under a low signal-to-noise ratio of a classifier; mine wireless channel model analysis: large-scale fading characteristic analysis and small-scale fading characteristic analysis; and feature extraction based on a high-order cumulant: constructing a second-order moment and a fourth-order moment of theidentified mine communication signal, normalizing the feature quantity of the second-order cumulant and the fourth-order cumulant, and analyzing the influence of a fading channel on the high-order cumulant. According to the method, the problem of low recognition rate of a common SVM classifier under a low signal-to-noise ratio is solved, and the modulation recognition performance is improved to acertain extent; in three channel environments with the signal-to-noise ratio of-5, the average recognition rate of the four signals can reach 80%; in three channel environments with the signal-to-noise ratio larger than-3, the average recognition rate of the four signals can reach 90%.
Owner:XIAN UNIV OF SCI & TECH
Hybrid field signal source positioning method based on symmetrical nested array
InactiveCN108919178AReduce computational complexityOvercoming noisePosition fixationComputation complexityNested arrays
The invention provides a hybrid field signal source positioning method based on a symmetrical nested array. The hybrid field signal source positioning method comprises the following steps that an antenna array is set, wherein the antenna array is the symmetrical nested array; a far-field signal DOA is estimated to obtain an estimation value of the far-field signal DOA; the near field component isseparated from the far field component; a fourth-order cumulant virtual difference array of a near-field signal is calculated; an estimation value of the near-field signal DOA is obtained by using spectral peak search; and according to the near-field signal DOA estimation value, the near-field signal distance is estimated to obtain a near-field signal distance estimation value. The hybrid field signal source positioning method uses mixed-order statistics, and compared with a second-order statistic algorithm, the hybrid field signal source positioning method solves the problems of Gaussian noise interference and reduction of degree of freedom by half; the symmetric nested array and the fourth-order cumulant virtual differential array are used for improving the estimation accuracy of far-field DOA, near-field DOA and a near-field distance; oblique projection technology is utilized to separate the far-field and near-field components, and thus, it is not necessary to distinguish the far-field signal from the near-field signal according to distance parameters; and therefore, the number of search is reduced, and the computational complexity of the algorithm is further reduced.
Owner:UNIV OF ELECTRONICS SCI & TECH OF CHINA
Multi-input and multi-output fast estimation method for radar receiving and transmitting angles under color-noise environment
InactiveCN103217671AImprove estimation performanceSuppresses the effect of Gaussian color noiseWave based measurement systemsMulti inputComputation complexity
The invention provides a multi-input and multi-output fast estimation method for radar receiving and transmitting angles under color-noise environment. The multi-input and multi-output fast estimation method comprises the following steps of: (1) carrying out matching and filtering on echo signals of all receiving array elements acquired by an A / D sampling module and obtaining received data of a virtual array; (2) carrying out rearrangement on the received data of the virtual array; (3) respectively carrying out subarray division on the received data and a rearranged matrix and meeting the characteristic of constant rotation of a transmitting end and a receiving end; (4) constructing two four-order cumulant matrix pairs; (5) obtaining signal subspaces including the characteristic of constant rotation in transmitting and receiving respectively by characteristic values; (6) estimating the receiving and transmitting angles of a target by utilizing an ESPRIT algorithm; and (7) realizing correct pairing of the receiving and transmitting angles by utilizing a maximum likelihood estimation method. The multi-input and multi-output fast estimation method provided by the invention has the advantages that the influence of Gaussian color noise can be effective inhibited, no special requirement exists for the quantity of transmitted / received array elements, the estimation accuracy is high, and the computation complexity is low, so that the multi-input and multi-output fast estimation method can be used for positioning targets on sea or at low altitude in tracking and guidance.
Owner:HARBIN ENG UNIV
Serial-connection fault arc detection device based on high-order cumulant identification and method thereof
InactiveCN106771898ASolve the problem of missing judgmentReduce processingTesting dielectric strengthInstrument transformerRelease - action
The invention relates to a serial-connection fault arc detection device based on high-order cumulant identification and a method thereof. The device comprises a rest current transformer, an MCU connected with the rest current transformer and a releasing mechanism connected with the null line and the live line. The MCU is connected with the releasing mechanism through a driving circuit. The method comprises steps that the MCU acquires rest current signals of an incoming line end of a circuit in real time through the rest current transformer and carries out four-order cumulant kurtosis value calculation according to preset calculation interval time; and when a kurtosis value with preset frequency value quantity is larger than the preset kurtosis value is continuously detected, the releasing circuit is driven to execute a releasing action to protect the circuit immediately. According to the invention, there is no need to judge the type of load, and a threshold value will not be changed along with the type of the load, so processing for unusual current during normal work of nonlinear load is avoided and problems of missing judgment and misjudgment of the system can be solved.
Owner:FUZHOU UNIV
Coherent signal direction finding method and system with unknown signal source number
InactiveCN104298850AEffective estimateDirection findersSpecial data processing applicationsIntermediate variableDecorrelation
The invention provides a coherent signal direction finding method and system with an unknown signal source number. The coherent signal direction finding method includes the initiating step, the fourth-order cumulant matrix calculating step, the Toeplitz matrix establishing step, the intermediate variable setting step, the power spectrum calculating step and the searching step. The method and system have the advantages that decorrelation is conducted on coherent signals by establishing the Toeplitz matrix based on fourth-order cumulant, the Toeplitz matrix is of a joint diagonalization structure, and therefore no priori knowledge about the signal source number is needed; a new cost function is designed, and therefore the direction of arrival can be effectively estimated.
Owner:HARBIN INST OF TECH SHENZHEN GRADUATE SCHOOL
Method for estimating two-dimensional direction-of-arrival of coherent signal source by means of L-shaped array based on time smoothing
ActiveCN107576947AEnhanced inhibitory effectImprove estimation performanceWave based measurement systemsSignal-to-noise ratio (imaging)Radar
The invention discloses a method for estimating a two-dimensional direction-of-arrival of a coherent signal source by means of an L-shaped array based on time smoothing. The method is implemented by the steps of: 1, transmitting a multi-period linear frequency modulation signal to a scene in the front by means of an L-shaped array radar, and receiving an echo signal reflected by the scene; 2, performing two-dimensional discrete sampling on the echo signal to obtain a matrix form of the echo signal, and carrying out fourth-order cumulant and time smoothing processing to obtain a covariance matrix; 3, constructing a noise subspace according to the covariance matrix, and constructing a signal subspace according to a matrix placement form; 4, and estimating a direction-of-arrival of a signal source according to orthogonality between the signal subspace and the noise subspace. The method can realize precise estimation of the two-dimensional direction-of-arrival of the coherent signal source, improves the direction-of-arrival estimation performance under a low signal-to-noise ratio, and can be used for measuring space angles of a stationary or moving target.
Owner:XIDIAN UNIV
Sound source positioning method and apparatus and time delay estimation method and apparatus
InactiveCN105609112AOvercoming the problem of increased positioning errorReduce noiseSpeech analysisPosition fixationSound sourcesPeak value
The application provides a sound source positioning method and apparatus and a time delay estimation method and apparatus. The time delay estimation method comprises: two-stage noise reduction processing is carried out on a received acoustical signal sent by a sound source to obtain a noise reduction signal; according to a four-order cumulant and a four-order cumulant cross spectrum of the noise reduction signal, a time delay estimation equation is defined; and according to the time delay estimation equation, time differences of arrival of acoustical signal at all microphones in a microphone array are estimated and obtained. According to the time delay estimation method, with the two-stage noise reduction processing and the four-order cumulant cross spectrum, influences of the noises and the interference are reduced; the time delay can be estimated accurately; and a problem that the sound source positioning error is increased due to the confused peak value around the acoustical signal delay and the Gaussian noise pollution influence according to the time-domain high-order statistics method and the generalized cross correlation-spectrum weight method can be solved.
Owner:北京爱宾果科技有限公司
Method for recognizing digital modulation signals under Alpha stable distribution noise
InactiveCN103997475AEasy to identifyImprove robustnessModulated-carrier systemsSignal-to-noise ratio (imaging)Engineering
A method for recognizing digital modulation signals under Alpha stable distribution noise comprises the following steps that received signals x(t) are subjected to preprocessing, baseband signals y(t) are obtained; the generalized second-order cumulant GC 20 and the generalized fourth-order cumulants GC 40 and GC 42 of y(t) are solved; the maximum value gamma max of the spectrum density of a generalized instantaneous phase based on fractional order Fourier transform is solved, and a judging threshold delta of a signal set is set; the feature that F1 is equal to GC20 and a minimum mean square error classifier are used for dividing signals into two types of {2PSK} and {MSK, QPSK and 8PSK}; gamma max and the set threshold delta are used for dividing the signal set of {MSK, QPSK and 8PSK} into two kinds of {MSK} and {QPSK and 8PSK}; and the feature that F2 is equal to GC40 / GC42 and the minimum mean square error classifier are used for recognizing the signals QPSK and 8PSK. According to the method, good recognizing performance on signals containing Alpha stable distribution noise under a low mixing signal to noise ratio can be achieved.
Owner:XIDIAN UNIV
Signal processing method and device
ActiveCN101661752AOvercome limitationsAdaptableSpeech analysisCharacter and pattern recognitionPartition matrixThird order cumulants
The embodiment of the invention relates to a signal processing method and a device. The method includes the following steps: in a period of time, receiving a mixed signal and obtaining the amplitude information of the received mixed signal; according to the third-order cumulant and the fourth-order cumulant of the amplitude information of the mixed signal, obtaining objective function through calculation; and using the objective function to obtain an independent signal in the mixed signal. The method can cause ICA algorithm to be applicable to unmixing treatment of various signals. Another method includes the following steps: using Newton iteration formula with a regulatory factor that can cause the objective function to descend according to given norm to conduct iterative treatment on initial weight vector until the iterated weight vector is converged, and obtaining the converged weight vector; receiving the mixed signal in a period of time and acquiring the amplitude information of the received mixed signal; and according to the converged weight vector, conducting unmixing treatment on the mixed signal and acquiring the independent signal in the mixed signal. The method has little restraint in selection of the initial value of the weight vector in partitioning matrix and high operation efficiency.
Owner:HUAWEI DEVICE CO LTD
Fourth-order cumulant based co-prime array DOA (Direction of Arrival) angle estimation method
ActiveCN106226729AIncrease the number of identifiable sourcesOvercome the disadvantage that the number of signals is lower than the number of array elementsRadio wave finder detailsRadio wave direction/deviation determination systemsEstimation methodsArray element
The invention discloses a fourth-order cumulant based co-prime array DOA (Direction of Arrival) angle estimation method, which mainly solves problems in the prior art that the utilization rate of array elements is low and that the signal identification number is small. The estimation method comprises the implementation steps of 1) respectively building a one-layer co-prime array and a two-layer co-prime array; 2) acquiring an output signal of the one-layer co-prime array and an output signal of the two-layer co-prime array; 3) calculating all fourth-order cumulants according to the output signal of the one-layer co-prime array and the output signal of the two-layer co-prime array; 4) constructing a fourth-order cumulant array according to all of the fourth-order cumulants; 5) calculating a noise sub-space of the fourth-order cumulant array; 6) calculating a spatial spectrum according to the noise sub-space of the fourth-order cumulants and an array manifold matrix; and 7) drawing an amplitude spectrum according to the spatial spectrum, and acquiring a DOA angle. The estimation method disclosed by the invention greatly improves the recognizable source number of an array under the condition that the number of array elements is limited, and is applicable to target reconnaissance and passive location.
Owner:XIDIAN UNIV
Hybrid signal source locating method and hybrid signal source locating system
InactiveCN107422299ASolve the positioning problemReduce parameter dimensionPosition fixationPhase responseComputation complexity
A hybrid signal source locating method includes: constructing a fourth-order cumulant matrix according to the received data of a uniform linear array model; estimating the two-dimensional electronic angles of the hybrid signal source one by one; performing eigen-decomposition on the covariance matrix of the received data of the uniform linear array model to estimate the amplitude-phase response of the array model; using a plurality of calibration elements to eliminate the blurring phase in the amplitude-phase response; performing iterative operation on the three processes of the two-dimensional electronic angle estimation, the amplitude-phase response estimation, and the blurring phase elimination until the convergence; obtaining the convergence values of the amplitude-phase response diagonal matrix and the two-dimensional electronic angles; determining the type of the incident signal source; and outputting an incident signal source locating result. The present invention also provides a hybrid signal source positioning system. The implementation of the technical schemes provided by the invention can effectively reduce the computational complexity and shorten the operation time for locating, and meanwhile locates the hybrid signal source of the near field and the far field, improving the locating accuracy and the application range.
Owner:HUIZHOU UNIV
Transformer substation partial discharge locating method based on spatial spectrum unambiguous estimation
InactiveCN107942212AReduce volumeSolution volumeTesting dielectric strengthTransformerSignal classification
The invention relates to a transformer substation partial discharge locating method based on spatial spectrum unambiguous estimation. The transformer substation partial discharge locating method is technically characterized by comprising the following steps that a uniform circular array is selected as an ultrahigh frequency antenna array; the acquired partial discharge signals are focused by usingthe least square algorithm; the azimuth angle and the pitch angle of a partial discharge source are calculated by using a multi-signal classification algorithm based on the fourth-order cumulant; andthe position of the antenna array is changed and the electric power equipment having partial discharge is determined. Transformer substation partial discharge is located by using the method based onspatial spectrum unambiguous estimation so that partial discharge detecting and locating of all the electric power equipment in the open transformer substation can be realized; besides, the detectingsystem has small size and has no problem of direction finding ambiguity so that the problems that the present partial discharge detecting system based on the ultrahigh frequency antenna array has large size and inspection is not implemented easily can be effectively solved, the cost of the large installing equipment state online detecting device can be greatly reduced and the detecting efficiencycan be enhanced.
Owner:STATE GRID TIANJIN ELECTRIC POWER +3
Method for acquiring heart sound signal source components
InactiveCN108392220AGood for in-depth analysisEasy to explainStethoscopeThoracic structureMathematical model
The invention discloses a method for acquiring heart sound signal source components. The method includes synchronously acquiring N channels of heart sound signals from multiple channels according to the 'time-sharing generation' characteristic of the heart sound signals, and carrying out denoising and segmentation processing on the heart sound signals; building mathematical models of transmissionprocedures of the heart sound signals in thoracic cavities; acquiring the heart sound signal source components on the basis of fourth-order cumulant algorithms. The method has the advantages that physiological information with the heart sound signals, heart sound generation location information and information of correlations between signals of the various channels can be acquired by the aid of the method; first heart sound S1 can be decomposed into four source components to be represented by the aid of the time-sharing generation characteristic of the heart sound signals, second heart sound S2 can be decomposed into two source components to be represented, accordingly, the heart sound signal source components with single components can be successfully acquired, and the method is favorablefor deeply analyzing, interpreting and classifying the heart sound signals and can be ultimately applied to clinical practice and further scientific research.
Owner:NANJING UNIV OF POSTS & TELECOMM
High-order cumulant-based method for multi-path propagation and separation of acoustic signals
ActiveCN105652264AHigh separation precisionAccurate separationPosition fixationAcoustic wave reradiationSound sourcesPropagation time
The invention discloses a high-order cumulant-based method for the multi-path propagation and separation of acoustic signals. According to the technical scheme of the invention, an original second-order cumulant-based active broadband signal separation method is extended to a fourth-order cumulant. According to the fourth-order cumulant, a corresponding duplicate vector and noise sub-space is constructed. Meanwhile, an additive noise is assumed to be a colored noise during the acoustic signal propagation process. Finally, an acoustic ray path is found out based on the orthogonality of the noise sub-space. The invention also discloses an acoustic ray propagation time tomography-based ocean acoustic tomography method and a sound source localization method. Compared with the prior art, the above method is higher in separation accuracy and can correctly separate acoustic ray paths of smaller intervals. Meanwhile, the method can be applied to conditions wherein the number of sensors is smaller than the number of ray paths. At the same time, the influence of both Gaussian noises and non-Gaussian noises can be inhibited.
Owner:SOUTHEAST UNIV
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