44 results about "Nested arrays" patented technology

The invention relates to the technical field of acoustic imaging, and discloses an acoustic imaging system of a concentric-circle nested microphone array, which comprises a central microphone and the concentric-circle nested microphone array. The concentric nested microphone arrays are concentrically arranged by taking the central microphone as the center, a plurality of microphones are distributed on each layer of circular microphone array according to a nested array rule, and the distance between each layer of adjacent microphone arrays is d. By adopting a unique circular nested microphone array structure, the position information of a sound source can be accurately captured through the cooperative work of multiple layers of microphone arrays. A plurality of microphones are distributed in each layer of microphone array in a circular nested array, a multi-dimensional sound acquisition network is formed by combining a central microphone, and meanwhile, the signal processing module gradually extracts and reconstructs sound source information in a sound field by utilizing a CLEAN-SC algorithm and through iterative decomposition and removal of strongest components in sound source signals, so that a sidelobe interference image is effectively inhibited, and the sound quality is improved. Therefore, a high-resolution sound power distribution diagram is obtained, and acoustic imaging is realized.

A multi-carrier signal angle and time delay estimation method based on a nested array belongs to the field of wireless communication, and comprises the following steps: firstly, designing a nested array set according to the number of radio frequency links and the number of pilot frequency carriers, and designing a beam forming matrix into a random banded Toeplitz matrix; meanwhile, selection of pilot frequency carriers is determined according to the nested array of the pilot frequency carriers. At a transmitting end, each pilot carrier transmits a unit matrix signal in each pilot block period time, at a receiving end, the signal received by each pilot carrier is vectorized, and all pilot carrier vectors are gathered to form a new pilot vector. The method comprises the following steps of: calculating a covariance of a new pilot frequency vector, selecting a maximum continuous holeless vector, improving a rank of the holeless vector by using a smoothing technology, finally solving a time delay, a departure angle and an arrival angle of each path by using a 3-D ESPRIT algorithm, and pairing all the time delays, departure angles and arrival angles through a MUSIC algorithm. After the method is used for processing data, a super-resolution method 3-D ESPRIT can be used for time delay and angle estimation, and the angle and time delay estimation precision is effectively improved.

The invention provides a multi-frequency distributed nested array DOA estimation method based on low-rank constraint, and the method comprises the steps: S1, building a receiving signal model of a distributed nested array, and obtaining a receiving signal based on the receiving signal model; s2, calculating a covariance matrix of the received signal, and performing vectorization processing on the covariance matrix to obtain a first virtual array corresponding to the distributed nested array; s3, extrapolating sub-arrays in the first virtual array to fill part of holes existing under the long baseline condition to obtain a second virtual array; s4, zero elements are inserted into the remaining hole positions to obtain a third virtual array, and the rank of the covariance matrix corresponding to the third virtual array is recovered; s5, establishing a matrix reconstruction model combining the low-rank constraint and the sparsity constraint, and solving to obtain a complemented covariance matrix; and S6, carrying out characteristic decomposition on the complemented covariance matrix to obtain a final DOA estimation value.

The invention discloses a 4D millimeter wave radar antenna and a nested array and an anti-interference design method thereof. According to the method, a multi-transmitting and multi-receiving orthogonal array is adopted to construct a larger equivalent virtual aperture under a limited size, and hardware adopts a double-layer waveguide and is matched with multi-resonance broadband matching to cover 76-81 GHz; a multifunctional nested sub-array is introduced to realize division cooperation of long-distance narrow beam, short-distance high resolution and pitching enhancement, and a side lobe is suppressed and the size of an array plane is reduced by sharing aperture and channel multiplexing; the frequency spectrum orthogonality and mutual interference resistance of the same-domain radar are improved through segmented calibration, online interference detection and sub-band selection and switching; on the premise of meeting the resolution, the size of the module is reduced through sparse topological optimization. According to the method, the stable detection distance and the weak and small target detection capability can be improved, the fusion and false association probability is reduced, unnecessary braking is reduced, missing detection / false alarm caused by mutual interference is reduced, and the constraint on the whole vehicle model and the installation window is reduced.

The invention discloses a DOA estimation method for a nested array structure, and the method comprises the steps: receiving data through a nested array, and calculating a covariance matrix of a received signal; vectorizing the covariance matrix of the received signal, and sorting and deleting a redundant part to obtain a virtual array received signal; extracting a continuous part of a virtual array receiving signal to obtain a receiving signal of a continuous virtual array; obtaining a received signal covariance matrix of the continuous virtual array through a spatial smoothing method; and carrying out eigenvalue decomposition on the covariance matrix to obtain a noise subspace, and constructing a rooting MUSIC formula to obtain a root and a corresponding DOA estimation result. According to the method, higher estimation precision can be realized, a spectrum peak search process is avoided, and the calculation complexity is relatively low.

This invention discloses a monostatic symmetric nested array MIMO system and a near-field positioning method, belonging to the field of monostatic MIMO near-field positioning technology. This invention can effectively improve the positioning performance during near-field estimation. The monostatic symmetric nested array MIMO system proposed in this invention has a symmetrically distributed transmit and receive arrays. Compared to other symmetric MIMO systems, its differential array is a positionally continuous array with more degrees of freedom. With the same physical array aperture, fewer physical array elements are actually used, reducing costs. The near-field positioning method proposed in this invention calculates the fourth-order statistics of the signal and quantizes them to obtain a virtual differential array of the differential array, achieving accurate near-field positioning of sparse MIMO structure arrays. Furthermore, it can be extended to more sparse MIMO symmetric systems.

The present invention relates to the technical field of underwater acoustic array signal processing, and discloses a nested array coherent target azimuth estimation method, system and terminal based on CLEAN. The target azimuth estimation method comprises: S1. configuring a nested array, receiving a narrowband signal, and constructing a narrowband signal model; S2. calculating the covariance matrix of a non-undersampled subarray; S3. calculating an estimated value of each target azimuth in the narrowband signal model; S4. constructing clear signals of the nested array for different targets, and calculating the covariance matrix of the clear signals of different targets; S5. vectorizing the covariance matrix of the clear signal to obtain a received signal of a virtual array; S6. calculating an updated estimated value of each target azimuth; S7. using the updated estimated value as input, cyclically executing steps S4 to S6, and repeating three times to obtain a target azimuth estimate. Compared with a method based on a uniform linear array with the same number of array elements, the present invention can achieve higher angular resolution, a narrower mainlobe width, and a lower sidelobe level.

The present invention discloses a composite ultra-wideband director, which is composed of a director vane and a magnetic current loop. The director vane is placed above the radiation surface of the oscillator, and the magnetic current loop is placed below the radiation surface of the oscillator with its vertical axis coinciding with that of the oscillator. In particular, by designing a double-layer director vane and a spiral magnetic current loop, the above-mentioned composite director realizes ultra-wideband plane wave conversion and gain improvement. The invention combines the plane wave conversion characteristic of the director vane with the characteristic of the magnetic current loop to improve the axial gain, providing a solution for a composite ultra-wideband and high-gain director, so as to better meet the requirements of current 5G ultra-wideband antennas. The present invention also provides a high-low frequency nested array.

The invention provides a constant-beam-width beam forming method based on a vector combination array, which aims at the problem of receiving broadband signals by an underwater acoustic measurement array, combines a vector nested linear array and a sound pressure circular array into the vector combination array, and can be used for measuring broadband radiation noise of an underwater acoustic target. Constant-beam-width beam forming based on a combined array is divided into three parts, namely a measurement beam width calculation part, a vector nested array constant-beam-width beam forming part and combined array constant-beam-width beam forming part, beam width changes under different frequencies are compensated through frequency weighting according to the nested array principle, and particularly, the beam width change under different frequencies is compensated through frequency weighting. A nested array is formed by constructing sub-arrays with different intervals, the main lobe beam width is ensured to be constant by adopting a method of linearly combining a sub-array directivity function, and in a signal processing process, a single linear array is subdivided into a plurality of different sub-arrays for operation, so that the complexity of the combined array is reduced, and the number of processing channels is also reduced.

The invention discloses a logical operation method based on depth-first traversal and stack recursion, and belongs to the technical field of computer logical operation and data processing. The method aims at solving the problems that in the prior art, when a complex nested logic expression is processed, operator priority judgment is complex, short circuit evaluation is difficult to achieve, and code maintainability is poor. The core of the method is that firstly, a nested logic expression to be calculated is abstracted into a tree-shaped or nested array data structure; secondly, a depth-first traversal algorithm is adopted to conduct recursive scanning on the data structure, and in the traversal process, encountered logic operators and basic judgment conditions (calculation factors) or intermediate calculation results of sub-expressions are sequentially pressed into a main stack according to the traversal sequence; when traversal of one sub-expression is completed, an actuator module is automatically triggered; and the executor module pops up a logic operator of the current action range from the main stack.

This invention belongs to the field of sound source localization technology and discloses a near-field sound source localization method based on a symmetrical nested array and weighted fourth-order cumulants. The invention uses a centrally symmetrical nested array as the signal receiving structure. By constructing a weighted fourth-order cumulant matrix, it improves the stability of statistical quantities while suppressing Gaussian noise, and establishes an equivalent high-order statistical model based on the array geometry. In the parameter estimation stage, a two-stage one-dimensional estimation strategy decoupling angle and distance is adopted: first, one-dimensional subspace estimation of angle is performed based on the weighted fourth-order cumulant matrix; then, one-dimensional search estimation of distance is performed under angle constraints, thereby avoiding the traditional two-dimensional spectral peak search process in the near field. Without increasing the array hardware complexity, this invention improves localization accuracy and stability through high-order statistical optimization and parameter estimation process improvement, while significantly reducing computational complexity, and has good engineering application value.

The invention relates to an off-grid compressed sensing DOA (direction of arrival) estimation method based on a rear nested array, and belongs to the technical field of array signal processing. Two uniform linear arrays are utilized to construct a rear nested array, a signal covariance matrix is constructed, an initial estimation angle is obtained, off-grid correction is performed through a first-order Taylor expansion method, and final angle estimation is realized after iteration is completed. The method has the advantages that the array aperture is expanded by using the improved rear nested array structure, the degree of freedom of the array is improved, and the direction of arrival of more incident signals can be estimated; through Taylor out-of-lattice correction, the problem that the accuracy of a compressed sensing DOA estimation method is reduced in a grid mismatch scene is successfully solved, and compared with a traditional method, the method can still keep the estimation performance of high accuracy and high success rate on the incident angle of the information source under the low signal-to-noise ratio.

The present invention relates to a multi-level sub-array extended nested array design method for reducing mutual coupling effect. The method comprises the following steps: determining a unit length between array elements of an augmented multi-level extended nested array; determining array parameters of the augmented multi-level extended nested array; setting the augmented multi-level extended nested array to be composed of a uniform sparse array ULA(0), X uniform arrays ULA(x.1) with a spacing of 2d, and X uniform arrays ULA(x.2) with a spacing of 2d; the augmented multi-level extended nested array uses a differential array to generate continuous virtual array elements. The present invention expands a plurality of identical dense uniform arrays, sets the spacing between the dense uniform arrays, and symmetrically migrates some array elements of the dense uniform arrays compared to ULA(0), so that under the condition of satisfying differential no-holes, a higher degree of freedom is obtained compared to the original nested array, and the mutual coupling effect between array elements is greatly reduced.

The invention discloses a nested array piezoelectric MEMS loudspeaker, which is formed by arranging, nesting and combining a plurality of piezoelectric MEMS loudspeaker units together, a unit vibrating diaphragm is composed of a central vibrating diaphragm and extended rectangular vibrating diaphragms, the four edges of the central vibrating diaphragm are respectively provided with one extended rectangular vibrating diaphragm, the outer edges of the extended rectangular vibrating diaphragms are connected with a supporting base, and the supporting base is connected with the piezoelectric MEMS loudspeaker units. The actuator units are mutually nested and arranged through partially extending diaphragm structures, and in order to avoid crosstalk, the actuator units are mutually isolated through supporting substrates and air gaps. The array actuator has the beneficial effects that the actuator unit adopts a cross-shaped vibrating diaphragm design, so that the effective vibration area and out-of-plane displacement are improved, and the sound pressure level output of each part of array actuator unit under the fixed substrate size is improved; by modulating the difference of excitation signal phases of each part of array units under different voltages and different frequencies and coordinating with the vibration synthesis design realized by combining the array units, the programmable application requirements of the enhanced hearing aid can be met.

The application discloses a 4D millimeter wave radar antenna and a nested array and anti-interference design method thereof. The method adopts a multi-transmitting and multi-receiving orthogonal array to construct a larger equivalent virtual aperture under a limited size, a double-layer waveguide is adopted for hardware, and a multi-resonance broadband matching is matched to cover 76-81 GHz; a multifunctional nested subarray is introduced to realize the division and cooperation of long-distance narrow beam, short-distance high resolution and pitch enhancement, and to suppress the sidelobe and reduce the array size through shared aperture and channel multiplexing; the spectral orthogonality and anti-interference ability with the same domain radar are improved through segmented calibration, online interference detection, subband selection and switching; under the premise of meeting the resolution, the module size is reduced through sparse topology optimization. The application can improve the stable detection distance and weak target detection ability, reduce the fusion and misassociation probability, reduce unnecessary braking, reduce the missed detection / false alarm caused by mutual interference, and reduce the constraint on the vehicle modeling and installation window.

This invention discloses a direction-of-arrival (DOA) estimation method based on a reorganized nested array configuration. The method comprises the following steps: reordering two subarrays of a nested array to construct a reorganized nested array configuration; calculating the differential co-array and its maximum continuous degree of freedom of the reorganized nested array; spatially sampling the target radiator based on the reorganized nested array and vectorizing the covariance matrix of the antenna array's received signal; reconstructing the incident signal components based on a compressed sensing method; and constructing a spectral function and performing a spectral peak search to estimate the DOA of the target radiator. The invention proposes a differential co-array with a hole-free characteristic in the reorganized nested array configuration, which expands the array's degrees of freedom and effective array aperture, enabling high-precision underdetermined DOA estimation.

The present invention discloses a sparse array arrangement method for wave direction estimation. Based on the nested array, the method retains the dense sub-array with a spacing of half the wavelength of the incident signal on the left side, rearranges the sparse sub-array on the right side, and sets a larger interval between the left and right sub-arrays, and the size of the interval is determined by the arrangement of the right sub-array. The basic steps for its implementation are: determining the number of array elements of the array, obtaining the parameters of the array through the configuration formula for maximizing the array aperture, and then substituting the parameters into the general formula of the array to determine the spacing set of each array element, and finally converting the array element spacing set into the array element position set. Compared with the traditional sparse array improved based on the nested array, the present design method effectively improves the aperture of the array under the condition of the same number of array elements, and at the same time improves the accuracy of the array for wave direction estimation. It is particularly pointed out that the design method of the present invention has a more obvious improvement in the array direction finding performance for the arrangement with a large number of array elements (greater than or equal to 26).

This application proposes a high-resolution imaging method, apparatus, and storage medium for a planar microphone array in the differential domain. The method is applied to typical planar sparse array structures such as two-dimensional nested arrays. By vectorizing the covariance matrix of the received signal, the differential comatrix of the original array is obtained. Acoustic imaging is then performed based on this differential comatrix, resulting in a uniform rectangular array with higher degrees of freedom in the differential domain. This allows for high-resolution acoustic imaging with a small number of microphones. Numerical simulation experiments show that, with the same number of microphones, the acoustic imaging localization algorithm based on the differential domain of the nested planar array achieves higher resolution than existing acoustic imaging algorithms that directly locate typical planar arrays.

The invention discloses an amplitude-phase error self-correction and direction-finding method and system for a nested array under impact noise, relates to the field of array signal processing, and aims to solve the problem that an algorithm falls into a local optimal solution due to the fact that an existing method depends on an additional correction source. Comprising the following steps: step 1, establishing a nested array receiving data model with amplitude phase errors; step 2, constructing a cosine transform Sigmoid kernel low-order matrix of the signal; 3, carrying out initial amplitude-phase error compensation, and improving the direction finding accuracy through a diagonal loading method; step 4, amplitude-phase error self-correction is carried out; 5, performing virtual extension on the low-order covariance matrix, and estimating the direction of arrival; step 6, establishing a fitness function, and updating the amplitude-phase error estimation matrix until the amplitude-phase error estimation value converges; 7, performing phase error estimation based on a quantum lizard algorithm; and step 8, repeatedly executing the step 3 to the step 7 until the maximum cycle index is reached, and outputting a direction-of-arrival estimation angle and an amplitude-phase error estimation result.

The present invention relates to a nested array design method based on multi-level sub-array expansion with enhanced degree of freedom, comprising: determining the unit length between array elements of the multi-level extended nested array; determining array parameters of the multi-level extended nested array; setting the multi-level extended nested array to be composed of a uniform sparse array ULA(0) and X identical uniform dense arrays ULA(x), and the expression thereof is: determining the array element positions of the multi-level extended nested array according to the multi-level extended nested array; the multi-level extended nested array uses a differential array to generate continuous virtual array elements. The present invention expands a plurality of identical dense uniform arrays and sets the spacing between the dense uniform arrays, thereby making full use of the differences between the dense uniform arrays, so that under the condition of satisfying the differential no-hole condition, a higher degree of freedom is obtained compared with the original nested array, and the mutual coupling influence between the array elements is reduced.

This invention discloses a high-degree-of-freedom, low-coupling sparse array design method based on fourth-order cumulants, comprising: A: constructing a non-Gaussian signal receiving model and constructing a fourth-order differential array of the non-Gaussian signal using fourth-order cumulants; B: constructing a coprime displacement array composed of two coprime displacement subarrays and determining the array parameters; C: constructing an expanded nested array composed of two nested subarrays and determining the array parameters; D: constructing an expanded nested coprime displacement array based on the coprime displacement array and the expanded nested array and determining the expansion factor, ultimately obtaining a high-degree-of-freedom, low-coupling sparse array based on fourth-order cumulants. This invention can achieve stronger anti-coupling capability while maintaining a degree of freedom comparable to existing sparse arrays, and can significantly improve the signal estimation accuracy and direction-of-arrival resolution.

A Ku-band self-biased circulator belongs to the field of microwave ferrite device technology. The circulator includes a composite substrate and a microstrip circuit formed on the composite substrate; wherein the composite substrate includes a secondary dielectric sheet and an array of ferrite rods nested within the secondary dielectric sheet, the array of ferrite rods being composed of nested array of ferrite rods and a primary dielectric substrate. This invention, by employing a composite substrate structure with array of ferrite rods nested within a primary dielectric substrate, effectively reduces the influence of demagnetizing fields through the placement of the rod-shaped ferrites. The synergistic generation of multiple rod-shaped ferrites produces a stable bias magnetic field, providing good control over the device's operating frequency range. While maintaining non-reciprocal characteristics, it significantly reduces magnetic loss in the Ku-band, thereby reducing insertion loss.

The utility model discloses a quick arrangement device for a micro-motion detection polygonal nested array. The quick arrangement device comprises five first fixing assemblies, five second fixing assemblies, five third fixing assemblies, a fourth fixing assembly and a plurality of stainless steel rod pieces, the stainless steel rod pieces which are not prone to stretching and deforming are adopted, the length of each layer is made according to the number of nested layers of the regular pentagonal array, practicability and convenience are comprehensively considered, the stainless steel rod pieces are achieved by connecting the rod pieces in series, operation is easy, and the difficulty of fast arrangement of the polygonal nested array is reduced; a plurality of triangular structures are formed by connecting stainless steel rod pieces among the five first fixing assemblies, the five second fixing assemblies and the five third fixing assemblies, and the stability of the rapid arrangement device for the array is improved.

The application discloses a kind of absolute polynomial correlation entropy DOA estimation methods under pulse noise environment, receive signal by nested array structure antenna, according to received signal and absolute polynomial correlation entropy operator APCO calculate corresponding covariance matrix;With vectorization, ordering and redundancy are removed, obtain new virtual uniform linear array received signal;The continuous part of half wavelength between difference virtual array elements is spatially smoothed, and the spatially smoothed covariance matrix is constructed, and then the precise estimation of DOA is obtained by using the MUSIC method.The method uses absolute polynomial correlation entropy operator APCO to suppress pulse noise outliers, constructs APCO matrix, not only without relying on prior knowledge of noise, but also can get rid of the limitation of traditional correlation entropy algorithm, and can realize high-precision DOA estimation in strong pulse noise, low SNR, limited number of snapshots environment.

The present invention proposes a constant-beamwidth beamforming method based on a vector combination array. To address the problem of wideband signal reception by an underwater acoustic measurement array, a vector nested linear array and a circular sound pressure array are combined into a vector combination array, which can be used to measure broadband radiated noise from underwater acoustic targets. The present invention divides the constant-beamwidth beamforming method based on the combination array into three parts: measurement beamwidth calculation, vector nested array constant-beamwidth beamforming, and combined array constant-beamwidth beamforming. Utilizing the principle of nested arrays, frequency weighting is used to compensate for beamwidth variations at different frequencies. Specifically, a nested array is formed by constructing subarrays with varying spacing, and a method of linearly combining the directivity functions of the subarrays is used to ensure a constant mainlobe beamwidth. During signal processing, a single linear array is subdivided into multiple subarrays for computation, reducing both the complexity of the combination array and the number of processing channels.

The invention provides a sparse array uplink beam forming method for a dual-function communication radar system, and the method comprises the following steps: 1, constructing a sparse array: employing a co-prime array, a nested array and an enhanced nested array, and expanding the aperture through a difference set virtual array and a sum set virtual array; 2, generating virtual array data: constructing measurement data through covariance matrix vectorization and pseudo covariance matrix vectorization; step 3, scene adaptive beam forming: for different angles, distributing a radar target and a communication user to different beams through a convex optimization tool; for the same angle, spatial diversity constraint and orthogonality constraint are introduced, an independent beam former is designed, and cross interference is suppressed. Fusion of aircraft communication and radar detection functions is supported, and target detection and information interaction efficiency in space tasks is improved.

The invention discloses a low-frequency radiation unit, and relates to the technical field of antenna radiation units, the low-frequency radiation unit comprises a radiator, the radiator comprises a plurality of radiation arm units and a plurality of balun structures respectively corresponding to the plurality of radiation arm units, each radiation arm unit comprises a first radiation arm and a second radiation arm, the balun structure comprises a first balun wire correspondingly connected with the first radiation arm and a second balun wire correspondingly connected with the second radiation arm, and the first radiation arm, the second radiation arm, the first balun wire and the second balun wire are all provided with choking coil structures. The choking coil structure comprises a first branch knot and at least one second branch knot perpendicular to the first branch knot, and the choking coil structure is used for blocking high-frequency current coupled to the low-frequency radiation unit. The invention aims to enable the high-frequency radiation unit of the nested array antenna to obtain a good broadband radiation characteristic under the condition that the high-frequency radiation unit does not need to be lifted.

The invention discloses a power grid security-oriented anti-impulse noise robust DOA estimation method and monitoring system, and the method comprises the steps: collecting a fault position signal through a nested array antenna, and obtaining the information of a received signal; establishing a p-order bounded nonlinear function, performing exponential kernel operation on received signal information, and calculating an equivalent exponential kernel covariance matrix; vectorizing the covariance matrix to obtain a virtual received signal; and removing redundancy of the virtual received signal, obtaining virtual uniform array information, constructing a spatial smooth matrix, obtaining an estimated value of the DOA by adopting a MUSIC method, and outputting DOA direction angle estimation of a spectral peak position of a fault position signal. According to the invention, the problems of low positioning precision, slow response speed and disjunction with power grid safety protection under impulse noise in a traditional method can be solved.

The embodiment of the invention discloses a non-uniform array design method and device, electronic equipment and a storage medium, and relates to the technical field of array signal processing.The method comprises the steps that array parameter information is configured, and the unit length d between extension nested arrays is determined; the abscissa of the non-uniform area array is determined according to the array element number Q and the unit length d on the transverse axis of the non-uniform area array, the abscissa corresponds to the array arrangement structure of the expanded nested array with the array element number Q, and the ordinate of the non-uniform area array is determined according to the array element number Q and the unit length d on the longitudinal axis of the non-uniform area array; coordinates of the non-uniform area array are obtained according to the horizontal coordinates and the vertical coordinates, and a differential synthesis array is obtained through calculation according to the coordinates of the non-uniform area array. According to the method, the flexibility and the accuracy of the non-uniform area array design are realized by accurately configuring the array parameter information, the array arrangement accuracy is improved, and the problems that the signal processing accuracy is influenced and the degree of freedom is low due to the serious mutual coupling problem in the prior art are solved.

The invention discloses a nested array spectrum sensing method and system based on spatial power spectrum characteristics, and the method comprises the steps: receiving a signal through a nested array, calculating a covariance matrix, and obtaining a single-snapshot equivalent signal after vectorization processing and redundancy removal; recovering a covariance matrix rank by adopting a spatial smoothing technology, and performing one-dimensional angle search based on an MVDR beam former to generate a spatial power spectrum; calculating the ratio of the maximum power value to the minimum power value of the space power spectrum, and constructing test statistics; comparing the test statistics with a preset threshold to judge the existence of the master user, and guiding the cognitive user to make a spectrum access decision; the sparse structure design of the nested array is optimized, the virtual array element aperture is expanded by using the differential common array principle, the spatial resolution and the detection precision of spectrum sensing are remarkably improved, and the defect that the physical aperture of a traditional uniform linear array is limited is overcome.