52 results about "Capon" patented technology

The invention discloses a robust wave beam forming method based on covariance matrix reconstruction and guide vector estimation. The method comprises the steps: firstly carrying out the eigenvalue decomposition of a covariance matrix of received data of an antenna, obtaining a noise subspace, estimating an arrival angle of an interference signal through a multi-signal classification method, calculating a guide vector, carrying out the correction through a robust Capon wave beam forming algorithm, solving the power of the interference signal according to the orthogonality of the guide vector, and constructing an interference and noise covariance matrix; constructing a constraint condition of an expected signal guide vector through finding the space orthogonal to the expected signal guide vector, and solving a precise expected signal guide vector according to the maximum output power. The method is robust for a guide vector error and an interference and noise covariance matrix error, which are caused by an array position error, a non-interconnection local scattering and total amplitude and phase errors. Compared with the prior art, the method is higher in output signal to interference and noise ratio, and is higher in output performances.

A method for resisting primary user impersonation attacks in cognitive radio belongs to the technical field of radio communication, particularly relates to sensing and processing of the signals in the cognitive radio system and identification of a signal source. The method comprises the following steps: reducing noise of a composite signal which is received during a spectrum sensing process, estimating number of the signal sources in the composite signal, and reconstructing various signals by a Capon beamformer; separating the signals of different radios, focusing the signals of different radios to separate out a transient signal and a modulation signal, analyzing the transient signal by wavelet transformation; extracting characteristic parameters and realizing identification of the signal source. The method for resisting the primary user impersonation attacks helps realize effective identification of the signal source and effectively resist the primary user impersonation attacks; and the method has a wide application scope, does not change a working mode of the existing primary user network, and satisfies operation requirements of FCC for a cognitive network.

The invention belongs to the technical field of MIMO radars, and provides a high resolution DOA estimation method and system. The method includes the following steps that all receiving antennas receive transmitting signals reflected by target sources; a receiving signal of each receiving antenna is scanned through the transmitting signals, so that the corresponding relay of each transmitting signal is obtained; the transmitting signals are adjusted according to the obtained delay, the conjugate of each adjusted transmitting signal is multiplied with the receiving signal of each antenna, and accordingly the phase positions, corresponding to all peak points, in the receiving signal of each receiving antenna are obtained; virtual expansion signals are established according to the obtained phase positions and adjusted transmitting waveform signals; novel receiving signals are formed by the virtual expansion signals and the receiving signals, the covariance and the Capon wave beams of the novel receiving signals are calculated to form coefficients, and thus DOA estimation is completed. According to the high resolution DOA estimation method and system, under the condition that antennas are not additionally arranged, estimated accuracy can be improved, and the number of target sources which can be estimated can be increased.

The invention belongs to the field of array signal processing and mainly relates to robustness of a standard Capon self-adaptive beam forming algorithm based on covariance matrix reconstruction to interference signal steering vector errors. The beam forming algorithm based on subspace interference-plus-noise covariance matrix reconstruction comprises the following steps: at first, utilizing matrix received data to estimate the steering vector a(theta d), d=2,3,...,D and the power sigma<2> d(theta d) of all D-1 interference signals and meanwhile estimate the noise power sigma<2>, wherein d=2,3,...,D; then reconstructing an interference-plus-noise covariance matrix R' according to the definition R of the interference-plus-noise covariance matrix; finally, constructing a signal covariance matrix in a relatively small angle range 1; taking the dominant eigenvector of the signal covariance matrix as a desired signal steering vector to estimate a(theta 1); together with the reconstructed R', obtaining a novel beam forming weighing vector W, wherein the formulas of R, R' and W are shown in the description. The beam forming method provided by the invention overcomes the defects of the conventional beam forming algorithm, thereby having good robustness to interference signal steering vector errors.

The invention discloses a sparse construction and reconstruction method of array space signals. Due to the fact that the angle of received incident signals changes constantly under the high dynamic condition, enough sampling signals can not be acquired to conduct traditional beam forming. According to the method, a gain test of the array space signals is conducted through the Capon beam forming method based on feature space decomposition, and establishment of a small-snapshot-number sparseness model and OPM reconstruction of the small-snapshot-number sparseness model are conducted based on the compressed sensing theory. The result shows that the method has the advantage of processing undersampled data and achieves estimation on the angle of arrival of the array signals. The method further shows that in the space signal processing field, sparsity makes extraction of related information faster and more effective, so that the signal acquisition cost and the signal processing cost are lowered. By means of the method, expected waveform gain can be obtained in the expected direction of arrival. Compared with a direct sampling method, the method can solve the small snapshot number problem occurring under the high dynamic condition and improve the robustness of a system.

The invention is applicable to the technical field of vehicle-mounted radars and provides a method for detecting people in a vehicle, a radar and a vehicle. The method comprises the following steps of: acquiring a plurality of paths of target echo signals when people are in the vehicle, and preprocessing each path of target echo signals to obtain a plurality of paths of digital target signals; calculating a CAPON spectrum of the plurality paths of digital target signals to obtain target two-dimensional thermodynamic diagram information, and establishing an in-vehicle people identification model according to the target two-dimensional thermodynamic diagram information; acquiring multiple paths of echo signals to be detected in the vehicle, repeating the steps of preprocessing and calculating the CAPON spectrum to obtain the two-dimensional thermodynamic diagram information to be detected, and determining whether people are in the vehicle or not according to the in-vehicle people identification model and the two-dimensional thermodynamic diagram information to be detected. The embodiment of the invention is not influenced by the environment, can accurately detect whether a resident person exists in the vehicle, and ensures the personal safety of resident children or people who are inconvenient to move in the vehicle.

A method for enhanced Capon beamforming includes the steps of providing a sensor array including a plurality of sensor elements where an array steering vector corresponding to a signal of interest (SOI) is unknown. A covariance matrix fitting relation is bounded for the unknown array steering vector by constraining the array steering vector using a constant norm and a spherical uncertainty set. The matrix fitting relation is then solved to provide an estimate of said array steering vector.

The present invention discloses a coherent signal source MIMO radar angle estimation method in non-stationary noise. The method concretely comprises the steps of: 1, performing system initialization;2, obtaining signal data being subjected to MIMO radar matching filter processing, and calculating a signal covariance matrix; 3, employing a conventional subspace algorithm to achieve angle estimation of an incoherent signal source; 4, constructing a new Toeplitz matrix; 5, rejecting the incoherent signal source, and obtaining a covariance matrix of the coherent signal source; 6, employing an m-Capon algorithm to perform angle estimation of the coherent signal source, and estimating a direction of arrival of a target; and 7, estimating a direction of departure of the target. The coherent signal source MIMO radar angle estimation method in non-stationary noise achieves angle estimation of the coherent signal source.

The present invention provides a non-uniform sampling and reconstruction method of broadband multi-frequency sparse signals. The method comprises: calculating signal initial frequency spectrum information according to a multi-threshold energy detection system; establishing a signal sampling model through adoption of the non-uniform sampling parameter of rapid search emission search signals according to the obtained information; estimating signal frequency spectrum information through adoption of a subspace method of estimation; obtaining a rebuilt matrix unknown vector; and rebuilding an original signal. The method provided by the invention firstly adopts the multi-threshold energy detection system to estimate the signal frequency spectrum information and select an appropriate sampling period, so that the computation cost is reduced; and moreover, a frequency spectrum estimation algorithm based on a CAPON is adopted in the frequency spectrum estimation, so that the signal frequency spectrum information is rapidly estimated. Through adoption of the multi-threshold energy detection algorithm and the frequency spectrum estimation algorithm based on the CAPON, the computation complexity is further reduced, the frequency spectrum estimation speed in the non-uniform sampling is accelerated, and the numerical value robustness of the algorithm in a limited signal to noise ratio is ensured.

The invention belongs to the field of radar signal processing, and discloses a no-fuzzy-parameter estimation method of a frequency diversity MIMO radar. The method comprises the steps of analyzing a relationship between a frequency increment and an element spacing which influence the traditional frequency diversity MIMO radar to form a distance-angle tight-coupling directional diagram, and designing a reasonable nonlinearly-increasing frequency increment; obtaining angle information of a target by transmitting a pulse of which the frequency increment is 0 and conducting Capon spectrum estimation; then transmitting a pulse of which the frequency increment increases nonlinearly, substituting the estimated angle information into a whole processing process, and combining the Capon spectrum estimation to obtain distance information of the target. According to the no-fuzzy-parameter estimation method of the frequency diversity MIMO radar, not only is the problem of distance-angle tight coupling of a frequency diversity MIMO radar transmitting directional diagram solved, but also the angle and no-fuzzy distance estimation of the target are achieved, and precise locating of the target is further achieved.

The invention provides a restraining method for direct path waves of a bi-static sonar system. The optimal weight is obtained by weighting an optimization model of a sparse constraint Capon wave beamformer; and a zero point is generated in the fixed direction of an array directional pattern through a zero point constraint wave beam forming technology, interference in the direction is eliminated,coherent interference is restrained, and thus the direct path waves are restrained. The bi-static sonar system is a bi-static configuration system, thus the receiving end can further receive the direct path waves with the amplitude being much larger than that of target echoes besides the target echoes. The deeper null can be generated beside the coherent interference, better tolerance can be achieved, low side lobes can be formed, and the capacity to SINR outputting by an array and steering vector angle mismatch resistance is improved.

The invention discloses a high-resolution distance image obtaining method. Aiming at a frequency modulated continuous wave radar, the method employs the Dechirp technology to achieve the transformation of the received frequency modulated continuous wave to a frequency domain, and employs a Capon method to achieve the recognition of target scattered points in distance, thereby obtaining the high-resolution HRRP of a target. The method can be used for forming a radar high-resolution one-dimensional distance image, and is good in application prospect because the introduced Capon method does not need order determination in advance.

The present invention belongs to the field of the radar signal processing technology, and discloses a signal arrival direction estimation method of the spectral function second derivative based on the minimum variance method. The method comprises: setting a radar uniform array, obtaining radar receiving data from the radar uniform line, and obtaining the steering vectors according to the radar uniform array; calculating the covariance matrix of the radar receiving data according to the radar receiving data, performing inversion of the covariance matrix, and obtaining the covariance inverse matrix of the radar receiving data; determining a Capon spatial spectrum function according to the steering vectors and the covariance inverse matrix of the radar receiving data; solving the second derivative of the Capon spatial spectrum function, and constructing a new spatial spectrum function according to the second derivative of the Capon spatial spectrum function; performing maximum likelihood estimation of the signal arrival direction according to the new spatial spectrum function, and obtaining the estimated value of the signal arrival direction; and improving the angular resolution and the robustness of the measure direction performance.

The invention discloses a capon operation table which comprises a table plate and a telescopic supporting frame, wherein the table plate is provided with a counting hole, fixed big clips, fixed small clips, a big upper clip moving hole, a big lower clip moving hole, a big lower clip pull wire hole, a small upper clip shifting activity slotted hole and a small clip fixing shifting slotted hole; and a main pull wire pedal rack drives a main pull wire to pull a main pull wire rod, a counter pull rod, a small upper clip pull wire rod and a big upper clip pull wire rod to operate a small upper clip, a big lower clip and a big upper clip of the table plate, so that the fixed big clips and the fixed small clips open or close simultaneously. When the capon operation table is not used, telescopic rod fixing bolts are loosened, the supporting frame, the table plate and a supporting plate are pushed and pressed, so that the capon operation table is placed and carried conveniently. The capon operation table is simple in structure, easy to assemble and disassemble, small in size, convenient to carry and use, easy to operate, high in efficiency, safe and reliable, can be used for castrating a large batch of chickens, is safe and effective for henneries and rural capon operators, and has high economic benefits and social benefits.

The invention belongs to the technical field of radars, and discloses a novel multi-channel SAR deception jamming identification and adaptive suppression method which can accurately identify, extractand suppress deception jamming. The method comprises the steps that a multi-channel SAR radar receives an echo signal, and distance-pulse compression and distance migration compensation are carried out on the echo signal; the azimuth FFT is transformed into the distance Doppler domain, and the difference between the ground object echo and the deception jamming in the space-time relationship is used to construct the airspace orthogonal weight vector of the ground object echo in the distance Doppler data domain Doppler channel by Doppler channel, and suppress a ground object echo signal; the residual after the suppression is detected Doppler channel by Doppler channel; the acquired interference Doppler channel is used to locate the interference distance along the distance direction; and finally, the acquired interference two-dimensional position is used to collect interference samples to estimate an interference covariance matrix, and a capon algorithm is used to carry out small-scale adaptive spatial filtering on an interference region.

The invention provides a Capon beamforming-based positioning method and device. According to the Capon beamforming-based positioning method and device, K receiving antennas are set to form a signal receiving array, and M signal transmitting points are set; a covariance matrix Rxx is calculated by using a signal matrix outputted by the signal receiving array; the constraint optimization problem of the linearly constraint minimum variance criterion is solved, so that a spectral function can be constructed; M maximum spectral peaks are searched; and a direction of arrival is calculated. According to the method, beacon points deployed in a monitoring area are adopted to be networked with a wireless gateway so as to communicate with the wireless gateway; data are transmitted to a cloud end through a wireless communication module; cooperative sensing is performed, and the information of signal transmitting points in a network coverage area is acquired and positioned; the monitoring data of the cloud end are matched with a map and the like, so that intelligent parking can be realized. With the method adopted, the number of vehicles does not need to be known in advance or estimated, and therefore sampling data length can be decreased; desired signals are enhanced, interference is suppressed, and therefore, the signal to interference plus noise ratio of the output of a system can be improved; and a robust Capon algorithm is modified to improve the deviation of a direction vector from an actual environment, and therefore, positioning performance can be improved.

The invention discloses an MIMO radar broadband DOA calculation method based on a sparse array in a clutter environment. The MIMO radar broadband DOA calculation method belongs to the field of singleprocessing, and specifically refers to WCSAB. According to the MIMO radar broadband DOA calculation method, clutter interference is suppressed by means of Capon beam forming, and then a target DOA isestimated by jointly using a CS method through utilizing different narrowband signal information. Considering that DOA estimation performance is not only related to a beamforming weight value, but also relates to a sparse array structure, the invention proposes a joint optimization problem of the beamforming weight value and the sparse array, and provides a simple algorithm to solve the optimization problem. According to the MIMO radar broadband DOA calculation method provided by the invention, the estimation performance including high resolution and low sidelobe of the target DOA in the clutter environment can be improved, the sparse array reduces the system cost and complexity, a Bayesian mean square error estimated by means of the target DOA is used as a performance evaluation index, and the sparse array structure designed by adopting the algorithm is similar to the optimal sparse array obtained through an exhaustion method in performance and is superior to a nested array and a co-prime array in performance.