24 results about "Nested arrays" patented technology

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.

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 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 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 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.

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 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 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.

The invention provides a GNSS (Global Navigation Satellite System) anti-interference receiving system and method with high degree of freedom and strong robustness. According to the system, a nested array composed of dense and sparse sub-arrays is constructed at the front end, and an equivalent virtual array is formed through non-uniform array element layout, so that the spatial processing degree of freedom far exceeding the number of physical array elements is obtained. Thirdly, the system adopts a difference set method to carry out statistical average on position information among array elements, and reconstructs a complete and stable virtual array covariance matrix in combination with an airspace smoothing technology; then, a power inversion algorithm is applied in a space-time domain, the spatial separation degree of a target signal is enhanced, and strong interference is effectively suppressed. And finally, a vector tracking loop is used for replacing a traditional scalar loop in a baseband part, accurate navigation information can be extracted from signals subjected to interference suppression, high-precision positioning in a complex electromagnetic environment is finally realized through multi-path elimination and pseudo-range calculation, and the robustness of the whole system is ensured.

This invention relates to the technical field of adaptive array signal processing, and particularly to a direction-of-arrival (DOA) estimation method based on an improved SAMP (Single Amplifier Array) using nested arrays. This method addresses the technical problems in the prior art. It involves incident a far-field narrowband signal onto an extended nested array. Based on the signal's position information, the array manifold matrix is ​​obtained, leading to the array received data matrix of the nested interpolated uniform array. Then, based on the characteristics of the compressed sensing matrix, the array manifold is extended to obtain a DOA estimation mathematical model. This model is input into an improved adaptive matched-tracking algorithm to reconstruct the original input signal. Finally, the MUSIC algorithm is used for spectral peak search. This method can accurately achieve DOA estimation under conditions of small snapshots, low signal-to-noise ratio, and source coherence; it has low computational complexity; it can accurately recover the source with relatively few samples; and it effectively improves the DOA estimation accuracy and spatial resolution of nested arrays.

The present application relates to the technical field of array signal processing and adaptive beamforming, and particularly relates to a covariance reconstruction and robust beamforming method based on geometric structure constraint, which realizes joint calibration of geometric error and statistical model through low-dimensional parameterized geometric modeling, strong direction signal auxiliary identification, interference and noise covariance matrix reconstruction and residual driven adaptive diagonal loading. The present application constrains position jitter estimation in a low-dimensional subspace through geometric structure prior, reduces estimation inadaptability and improves stability; realizes joint estimation of geometric parameters and covariance parameters through opportunistic calibration using multiple strong signal direction information; improves robustness in the presence of insufficient snapshots, model residuals or angle errors through reconstruction of INCM and combination of adaptive diagonal loading; the method steps and mathematical structure can be naturally extended to coprime arrays, nested arrays, general sparse arrays and two-dimensional / three-dimensional distributed arrays.

The invention discloses a symmetric sparse linear array design method based on the wavelet-like principle, and belongs to the technical field of array signal processing and direction estimation algorithms, a sparse linear array structure designed by the method is centrosymmetric, and the core idea of the sparse linear array structure is analogous to the wavelet theory. According to the invention, the structure is simple and easy to implement, just like extracting different frequency components of a signal through wavelet functions of different scales in wavelet analysis, the structure can not only avoid fuzziness in an end fire direction, but also expand an effective aperture, DOA estimation can be carried out by directly using a Root-MUSIC algorithm based on the array, complex covariance vectorization and reconstruction are not needed, and a simulation result shows that the DOA estimation efficiency is greatly improved. According to the method, the DOA estimation performance equivalent to that of a super-nested array can be realized while the relatively low calculation complexity is kept.

The invention relates to the technical field of DOA estimation, and discloses a DOA estimation system of an L-shaped super enhanced nested array, which comprises an L-shaped array, the array is composed of two super enhanced nested sub-arrays, and the two super enhanced nested sub-arrays are perpendicular to each other to form the L-shaped array. The super enhanced nested array is further improved on the basis of a nested array, and on the basis of improving the freedom degree of the array and expanding the aperture of the array, the mutual coupling effect between sensors is reduced, so that the positioning precision is improved. Through the DOA estimation system of the L-shaped super enhanced nested array, the azimuth angle and the pitch angle of each part of the array are estimated respectively, then pairing of the azimuth angle and the pitch angle is completed by using a cross covariance matrix of data of each part, two-dimensional DOA estimation is achieved, the complex two-dimensional spectrum peak search is changed into simple one-dimensional spectrum peak search, and the estimation accuracy is improved. And the calculation complexity of the system is obviously reduced.

The invention discloses an absolute polynomial correlation entropy DOA estimation method in an impulse noise environment, and the method comprises the steps: receiving a signal through a nested array structure antenna, and calculating a corresponding covariance matrix according to the received signal and an absolute polynomial correlation entropy operator APCO; vectorization, sorting and redundancy elimination are carried out to obtain a new virtual uniform linear array receiving signal; and spatial smoothing processing is carried out on a continuous part of which the array element spacing of the difference virtual array is half wavelength, a spatial smoothing covariance matrix is constructed, and accurate estimation of the DOA is obtained by using a MUSIC method. According to the method, the absolute polynomial correlation entropy operator APCO is used for inhibiting the pulse noise abnormal value, the APCO matrix is constructed, dependence on priori knowledge of noise is not needed, limitation of a traditional correlation entropy algorithm can be eliminated, and high-precision DOA estimation can be achieved in the environment of strong pulse noise, low signal-to-noise ratio and limited snapshot number.

The application discloses a MongoDB nested array document migration synchronization method and system based on DataX, belongs to the technical field of databases and data migration, and will convert a nested array document Document object list read according to configuration into different types of data according to different requirement configuration parameters exportType; if the custom parameter exportType is empty, the original Document document format of the migrated data is reserved; if the custom parameter exportType is json, the migrated data is in a json array format; if the custom parameter exportType is csv, the migrated data is in a csv format; if the custom parameter exportType is expand, the nested array document of the migrated data is separated into independent records and output; different data formats are distinguished through parameters, different apis are called, and different business requirements are met. The application is suitable for the synchronization of the nested array document in the MongoDB to a new database system.

The application belongs to the technical field of array antenna signal processing, and particularly relates to a nested array antenna mutual coupling elimination method and device based on a mixed near-field and far-field source. e The method comprises the following steps: modeling array antenna receiving signals according to an unknown mutual coupling matrix, a near-field array flow pattern, a far-field array flow pattern, a near-field source, a far-field source and noise; constructing the unknown mutual coupling matrix C e from a unit matrix I and a mutual coupling parameter matrix C whose mutual coupling parameter is not 1; when the unknown mutual coupling exists, constructing a steering vector expression, and converting the steering vector into a form of a sum of two sub-matrices; constructing the mutual coupling parameter matrix C according to the steering vector, and then solving a DOA estimation value and a mutual coupling parameter estimation value through one-dimensional search on the DOA and the mutual coupling parameter; and compensating the unknown mutual coupling matrix C e by using the mutual coupling parameter estimation value to constitute an estimation value of the unknown mutual coupling matrix. The application estimates the mutual coupling parameter of the array antenna, thereby performing mutual coupling compensation, and realizing elimination of mutual coupling interference.

The application relates to a universal nested array configuration family antenna and a design method thereof, and comprises the following steps: determining the number of array elements and the element spacing of a three-level sparse subarray; designing a universal nested array configuration family and deducing the element position distribution; analyzing the internal geometric characteristics of each subarray in each array configuration in the family from a two-dimensional perspective; deducing the analytical expression of the continuous degrees of freedom of each array configuration in the nested array configuration family under the differential common array domain, and analyzing the influence of the value of a sequence factor in the array configuration family on the degrees of freedom. The application introduces the concept of "family" into the design of a sparse array, and proposes a design method of the nested array configuration family antenna. Different from a certain fixed array configuration, each array in the family can be transformed into each other, and the flexibility of the array layout is significantly increased.

The invention discloses a satellite communication linear interference suppression method based on a nested array, and belongs to the technical field of satellite communication interference suppression, and the method comprises the following steps: 1, obtaining a nested subarray signal covariance matrix under array amplitude-phase errors; 2, estimating an amplitude-phase error matrix of the nested array; 3, correcting a nested array covariance matrix, a pseudo covariance matrix and an amplification covariance matrix; 4, constructing a difference summation common array and interpolating to form a virtual uniform linear array; 5, recovering interpolation difference summation common-array virtual linear signal vectors; 6, estimating a satellite communication linear signal direction; 7, estimating satellite communication linear signal power; 8, reconstructing a nested array amplification interference and noise covariance matrix; and 9, calculating a satellite communication nested array amplification weighting vector. According to the method, the linear interference suppression performance of satellite communication under the nested array amplitude-phase error is improved.