Broadband high-resolution robust beam forming method, device and equipment based on space-frequency mutual coupling domain phase difference compensation and storage medium

Abstract

The invention discloses a broadband high-resolution robust beam forming method and device based on space-frequency mutual coupling domain phase difference compensation, equipment and a storage medium, and the method comprises the steps: converting an underwater time domain receiving signal to a space-frequency mutual coupling domain according to a preset frequency domain conversion algorithm, determining an expected airspace phase difference corresponding to a preset reference frequency and phase compensation information corresponding to the initial underwater receiving signal according to the preset reference frequency, the sound velocity of the medium in water and the distance between adjacent array elements; performing phase correction on the initial underwater received signal; determining an optimal underwater receiving beam weight vector according to a preset optimal receiving beam weight limitation formula, the standard covariance matrix and the steering vector uncertainty set; the underwater broadband high-resolution robust beam is formed based on the received signal strength of each preset scanning direction, so that the anti-interference capability of the underwater broadband high-resolution robust beam and the accuracy of an underwater orientation result can be improved, and reliable detection and high-precision orientation of a broadband signal target in a complex underwater sound environment can be realized.

Description

Technical Field

[0001] This application belongs to the field of underwater acoustic detection technology, specifically relating to a broadband high-resolution robust beamforming method, apparatus, device, and storage medium based on spatial-frequency mutual coupling domain phase difference compensation. Background Technology

[0002] The core requirement of underwater broadband high-resolution robust beamforming is to receive underwater acoustic signals radiated or reflected by a target using a hydrophone array, and then identify the target's spatial location by analyzing these signals. Broadband signals, due to their richer target characteristic information and stronger anti-interference potential in complex underwater environments, have become the mainstream signal form for underwater broadband high-resolution robust beamforming. To ensure accurate target orientation, precise resolution of underwater broadband signals has become a key research topic in the field of underwater acoustic communication.

[0003] In related technologies, the main approach to underwater broadband high-resolution robust beamforming involves constraining the true steering vector of the received underwater signal within a defined set for analysis. This aims to suppress interference signals in the underwater signal while tolerating certain model errors. However, these technologies have low compatibility with the spatial-frequency coupling characteristics of broadband signals, resulting in poor anti-interference capabilities and low accuracy in direction finding for underwater broadband high-resolution robust beamforming. Summary of the Invention

[0004] This application provides a broadband high-resolution robust beamforming method, apparatus, device, and storage medium based on spatial-frequency mutual coupling domain phase difference compensation. It solves the problems of poor anti-interference capability and low direction-finding accuracy in related technologies for underwater broadband high-resolution robust beamforming. By determining phase compensation information to correct the phase of the initial underwater received signal, and then performing parameterized phase correction based on the phase compensation information, a standard underwater received signal is obtained. The optimal underwater received beam weight vector corresponding to a preset hydrophone array is determined, and an underwater broadband high-resolution robust beam is formed according to the received signal strength in each preset scanning direction. This achieves full-band phase difference compensation for the underwater received signal, ensuring the reception of the target signal while stabilizing and suppressing interference signals, thus improving the anti-interference capability of the underwater broadband high-resolution robust beam and consequently increasing the accuracy of the underwater direction-finding results.

[0005] In a first aspect, embodiments of this application provide a broadband high-resolution robust beamforming method based on space-frequency mutual coupling domain phase difference compensation, the method comprising: The underwater time-domain received signal received by the preset hydrophone array is acquired, and the underwater time-domain received signal is converted to the space-frequency mutual coupling domain according to the preset frequency domain conversion algorithm to obtain the initial underwater received signal, which is used for phase difference compensation in the mutual coupling domain. The sound velocity in the water medium and the spacing between adjacent elements of the preset hydrophone array are determined respectively. The desired spatial phase difference corresponding to the preset reference frequency is determined based on the preset reference frequency, the sound velocity in the water medium and the spacing between adjacent elements, and is used to calculate the phase compensation factor. Based on the desired spatial phase difference, multiple compensation factors corresponding to the initial underwater received signal are determined, and the multiple compensation factors are integrated to obtain the phase compensation information corresponding to the initial underwater received signal. Based on the phase compensation information, the initial underwater received signal in the space-frequency mutual coupling domain is phase difference compensated and corrected to obtain a standard underwater received signal, which is used for phase alignment in the space-frequency mutual coupling domain. The standard covariance matrix of the standard underwater received signal is calculated, and the steering vector uncertainty set is generated according to the preset steering vector set parameters, which is used to calculate the broadband high-resolution robust beam weight. Based on the preset optimal receiving beam weight constraint formula, standard covariance matrix and steering vector uncertainty set, determine the optimal underwater receiving beam weight vector corresponding to the preset hydrophone array, which is used to adjust the receiving coefficient of the preset hydrophone array; Upon reading the current received signals in each preset scanning direction received by the preset hydrophone array after adjustment based on the receiving coefficient, the received signal strength in each preset scanning direction is determined, and broadband high-resolution robust beam orientation is performed based on multiple signal strengths to form an underwater broadband high-resolution robust beam.

[0006] Furthermore, based on the preset optimal receiving beam weight constraint formula, the standard covariance matrix, and the steering vector uncertainty set, the optimal underwater receiving beam weight vector corresponding to the preset hydrophone array is determined, including: Based on the first correlation between the preset covariance matrix and the received beam weight, the standard covariance matrix, the second correlation between the preset steering vector and the received beam weight, and the nominal steering vector in the uncertainty set of the steering vector, an optimization formula for the received beam weight is constructed. The nominal steering vector is a theoretical steering vector corresponding to the standard underwater received signal, determined based on the preset reference frequency. Based on the preset optimal receiving beam weight constraint formula and the receiving beam weight optimization formula, calculate the optimal underwater receiving beam weight vector corresponding to the preset hydrophone array.

[0007] Furthermore, based on the preset optimal receiving beam weight constraint formula and the receiving beam weight optimization formula, the optimal underwater receiving beam weight vector corresponding to the preset hydrophone array is calculated, including: Based on the receive beam weight optimization formula, a Lagrange equation associated with the nominal steering vector and the receive beam weight is constructed, and the optimal Lagrange multiplier is calculated according to the Lagrange equation. Based on the preset optimal receiving beam weight constraint formula, nominal steering vector, standard covariance matrix, and optimal Lagrange multipliers, calculate the optimal underwater receiving beam weight vector corresponding to the preset hydrophone array.

[0008] Furthermore, the preset optimal receiving beam weight constraint formula is as follows: ; in, It is the optimal underwater receiving beam weight vector. It is the standard covariance matrix, It is the optimal Lagrange multiplier. It is the nominal guide vector. It is the symbol for the conjugate transpose. It is an identity matrix.

[0009] Furthermore, the preset guide vector set parameters include the preset guide vector set shape parameters and the preset guide vector set uncertainty radius; An uncertain set of guidance vectors is generated based on preset guidance vector set parameters, including: The actual steering vector is determined based on the standard underwater received signal, and the nominal steering vector corresponding to the standard underwater received signal is determined based on the preset reference frequency. Calculate the deviation between the actual and nominal guidance vectors, and generate an uncertainty set of guidance vectors based on the deviation, the shape parameters of the preset guidance vector set, and the uncertainty radius of the preset guidance vector set.

[0010] Furthermore, after determining the received signal strength in each preset scanning direction and performing broadband high-resolution robust beam orientation based on multiple signal strengths to form an underwater broadband high-resolution robust beam, the method further includes: The received signal strength in each scanning direction is calculated based on the optimal underwater receiving beam weight vector and the current steering vector in the current received signal. Based on the azimuth sequence corresponding to each scanning direction, the received signal strength of all scanning directions is integrated to generate an underwater target azimuth spectrum; The azimuth angle corresponding to the peak signal intensity in the underwater target azimuth spectrum is extracted to obtain the underwater target orientation result.

[0011] Secondly, embodiments of this application provide a broadband high-resolution robust beamforming apparatus based on space-frequency mutual coupling domain phase difference compensation, the apparatus comprising: The signal conversion module is used to acquire the underwater time-domain received signal received by the preset hydrophone array, and convert the underwater time-domain received signal to the space-frequency mutual coupling domain according to the preset frequency domain conversion algorithm to obtain the initial underwater received signal for mutual coupling domain phase difference compensation. The spatial phase difference determination module is used to determine the sound velocity of the medium in water and the spacing between adjacent elements of the preset hydrophone array, respectively. Based on the preset reference frequency, the sound velocity of the medium in water and the spacing between adjacent elements, the desired spatial phase difference corresponding to the preset reference frequency is determined and used to calculate the phase compensation factor. The compensation information determination module is used to determine multiple compensation factors corresponding to the initial underwater received signal based on the desired spatial phase difference, and integrate the multiple compensation factors to obtain the phase compensation information corresponding to the initial underwater received signal. The phase correction module is used to perform phase difference compensation correction on the initial underwater received signal in the space-frequency mutual coupling domain based on phase compensation information to obtain a standard underwater received signal for phase alignment in the space-frequency mutual coupling domain. The covariance matrix calculation module is used to calculate the standard covariance matrix of the standard underwater received signal. The set generation module is used to generate an uncertain set of guide vectors based on preset guide vector set parameters; The weight vector determination module is used to determine the optimal underwater receiving beam weight vector corresponding to the preset hydrophone array based on the preset optimal receiving beam weight constraint formula, standard covariance matrix and steering vector uncertainty set, and is used to adjust the receiving coefficient of the preset hydrophone array. The beamforming module is used to determine the received signal strength in each preset scanning direction when the current received signal is received in each preset scanning direction by the preset hydrophone array after the receiving coefficient is adjusted, and to perform broadband high-resolution robust beam orientation based on multiple signal strengths to form an underwater broadband high-resolution robust beam.

[0012] Thirdly, embodiments of this application provide an electronic device including a processor, a memory, and a program or instructions stored in the memory and executable on the processor, wherein the program or instructions, when executed by the processor, implement the steps of the method described in the first aspect.

[0013] Fourthly, embodiments of this application provide a readable storage medium on which a program or instructions are stored, which, when executed by a processor, implement the steps of the method described in the first aspect.

[0014] Fifthly, embodiments of this application also provide a computer program product comprising a computer program stored in a computer-readable storage medium, wherein at least one processor of the device reads from the computer-readable storage medium and executes the computer program, causing the device to perform the method described in the first aspect.

[0015] In this embodiment, the underwater time-domain received signal received by a preset hydrophone array is acquired, and converted to the space-frequency mutual coupling domain according to a preset frequency domain conversion algorithm to obtain an initial underwater received signal for phase difference compensation in the mutual coupling domain. The underwater medium sound velocity and the spacing between adjacent elements of the preset hydrophone array are determined respectively. Based on a preset reference frequency, the underwater medium sound velocity, and the spacing between adjacent elements, the desired spatial phase difference corresponding to the preset reference frequency is determined for calculating the phase compensation factor. Multiple compensation factors corresponding to the initial underwater received signal are determined based on the desired spatial phase difference, and these multiple compensation factors are integrated to obtain phase compensation information corresponding to the initial underwater received signal. Based on the phase compensation information, phase difference compensation correction is performed on the initial underwater received signal in the space-frequency mutual coupling domain. A standard underwater received signal is obtained for phase alignment in the space-frequency mutual coupling domain. The standard covariance matrix of the standard underwater received signal is calculated, and a steering vector uncertainty set is generated based on the preset steering vector set parameters to calculate the broadband high-resolution robust beam weight. Based on the preset optimal receiving beam weight constraint formula, the standard covariance matrix, and the steering vector uncertainty set, the optimal underwater receiving beam weight vector corresponding to the preset hydrophone array is determined to adjust the receiving coefficient of the preset hydrophone array. When the current received signal in each preset scanning direction of the preset hydrophone array after adjustment based on the receiving coefficient is read, the received signal strength in each preset scanning direction is determined, and broadband high-resolution robust beam orientation is performed based on multiple signal strengths to form an underwater broadband high-resolution robust beam. The above-described broadband high-resolution robust beamforming method based on spatial-frequency mutual coupling domain phase difference compensation solves the problems of poor anti-interference capability and low direction finding accuracy in related technologies. By determining phase compensation information to correct the initial underwater received signal, a standard underwater received signal is obtained. The optimal underwater received beam weight vector corresponding to the preset hydrophone array is determined, and an underwater broadband high-resolution robust beam is formed according to the received signal strength in each preset scanning direction. This achieves full-band phase difference compensation for the underwater received signal, ensuring the reception of the target signal while stabilizing and suppressing interference signals. This improves the anti-interference capability of the underwater broadband high-resolution robust beam, thereby improving the accuracy of the underwater direction finding results. Attached Figure Description

[0016] Figure 1 This is a flowchart of a broadband high-resolution robust beamforming method based on spatial-frequency mutual coupling domain phase difference compensation provided in an embodiment of this application; Figure 2 This is a schematic diagram of the preset hydrophone array receiving signals provided in the embodiments of this application; Figure 3 This is a schematic diagram of broadband high-resolution beam spatial spectrum simulation provided in the embodiments of this application; Figure 4This is a flowchart of determining the optimal underwater receiving beam weight vector of a preset hydrophone array, provided in an embodiment of this application. Figure 5 This is a structural block diagram of a broadband high-resolution robust beamforming device based on spatial-frequency mutual coupling domain phase difference compensation provided in an embodiment of this application; Figure 6 This is a structural block diagram of the electronic device provided in the embodiments of this application. Detailed Implementation

[0017] To make the objectives, technical solutions, and advantages of this application clearer, specific embodiments of this application are described in detail below with reference to the accompanying drawings. It is understood that the specific embodiments described herein are merely for explaining this application and not for limiting it. Furthermore, it should be noted that, for ease of description, only the parts relevant to this application are shown in the drawings, not all of them. Before discussing exemplary embodiments in more detail, it should be mentioned that some exemplary embodiments are described as processes or methods depicted as flowcharts. Although the flowcharts describe operations (or steps) as sequential processes, many of these operations can be performed in parallel, concurrently, or simultaneously. Furthermore, the order of the operations can be rearranged. The process can be terminated when its operation is completed, but may also have additional steps not included in the drawings. The process can correspond to a method, function, procedure, subroutine, subprogram, etc.

[0018] The technical solutions of the embodiments of this application will be clearly described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application are within the scope of protection of this application.

[0019] The terms "first," "second," etc., used in the specification and claims of this application are used to distinguish similar objects and not to describe a specific order or sequence. It should be understood that such use of data can be interchanged where appropriate so that embodiments of this application can be implemented in orders other than those illustrated or described herein, and the objects distinguished by "first," "second," etc., are generally of the same class and the number of objects is not limited; for example, a first object can be one or more. Furthermore, in the specification and claims, "and / or" indicates at least one of the connected objects, and the character " / " generally indicates that the preceding and following objects are in an "or" relationship.

[0020] First, this solution can be applied to scenarios involving underwater broadband high-resolution robust beamforming using broadband active sonar or underwater acoustic detection systems, particularly in scenarios where the spatial orientation of a target is determined based on the underwater broadband signal received by a hydrophone array. By determining phase compensation information to correct the phase of the initial underwater received signal, a standard underwater received signal is obtained. The optimal underwater received beam weight vector corresponding to the preset hydrophone array is determined, and an underwater broadband high-resolution robust beam is formed based on the received signal strength in each preset scanning direction. This achieves full-band phase difference compensation for the underwater received signal, ensuring the reception of the target signal while stabilizing and suppressing interference signals. This improves the anti-interference capability of the underwater broadband high-resolution robust beam, thereby increasing the accuracy of the underwater direction finding results. Based on the above application scenarios, it is understood that the execution entity for each step in this solution can be a computer device. This computer device refers to any electronic device with data computing, processing, and storage capabilities, such as mobile phones, PCs (Personal Computers), tablet computers, and other terminal devices, or servers, etc. This application embodiment does not limit this.

[0021] The following description, in conjunction with the accompanying drawings, details a broadband high-resolution robust beamforming method, apparatus, device, and storage medium based on spatial-frequency mutual coupling domain phase difference compensation, provided by the embodiments of this application, through specific implementations and application scenarios.

[0022] Figure 1 This is a flowchart illustrating a broadband, high-resolution, robust beamforming method based on spatial-frequency mutual coupling domain phase difference compensation, as provided in an embodiment of this application. Figure 1 As shown, the specific steps include the following: S101: Obtain the underwater time-domain received signal received by the preset hydrophone array, and convert the underwater time-domain received signal to the space-frequency mutual coupling domain according to the preset frequency domain conversion algorithm to obtain the initial underwater received signal, which is used for mutual coupling domain phase difference compensation.

[0023] The preset hydrophone array can be an array composed of receiving carriers used to receive underwater acoustic signals. In this scheme, the preset hydrophone array is a uniform linear hydrophone array, consisting of... It consists of 1 array element, and the spacing between adjacent array elements is 1 / 2. Each element in the preset hydrophone array can receive a set of signals in different frequency bands. The preset frequency domain conversion algorithm can be a pre-set algorithm used to convert the time-domain received signals acquired by the preset hydrophone array into frequency-domain signals. The preset frequency domain conversion algorithm in this scheme is the Fast Fourier Transform (FFT) algorithm. The initial underwater received signal can be the spatial-frequency coupled underwater received signal matrix obtained by performing Fast Fourier Transform and spatial-frequency matrix integration on the time-domain underwater received signals received by each element in the preset hydrophone array. The phase compensation information can be the information used to calibrate the spatial phase difference of each frequency point of the initial underwater received signal. The spatial-frequency coupled domain is a signal processing domain that simultaneously integrates the spatial dimension of the hydrophone array elements and the frequency dimension of the received signal spectrum, and describes the coupling relationship between the two. The spatial-frequency coupled domain transforms the broadband time-domain signal received by the hydrophone array using Fourier Transform, and integrates the transformation results according to the spatial position of each element, transforming it into a two-dimensional matrix that correlates the spatial position of the elements with the frequency, thereby realizing the joint description and collaborative processing of the spatial distribution and frequency characteristics of the broadband signal.

[0024] In one embodiment, the underwater time-domain received signal received by each element in a preset hydrophone array can be read, and the underwater time-domain received signal can be converted to the frequency domain according to a preset frequency domain conversion algorithm. Then, according to the spatial distribution of each element in the preset hydrophone array, the frequency domain conversion results of the underwater time-domain received signal received by each element can be integrated into a matrix form to realize the conversion of the underwater time-domain received signal to the space-frequency mutual coupling domain, resulting in a two-dimensional matrix in which the spatial position of the element is associated with the frequency. Each element in the matrix precisely corresponds to the frequency domain signal that can be received at a specific frequency at the spatial position of each element. This two-dimensional matrix is ​​used as the initial underwater received signal, which is used to provide the basic signal for phase difference compensation in the mutual coupling domain.

[0025] Figure 2 This is a schematic diagram of the preset hydrophone array receiving signals provided in an embodiment of this application. For example... Figure 2 As shown in the figure, the underwater installations are numbered from... The preset hydrophone array composed of array elements, the propagation medium, and the far-field noise source, This represents the angle between the signal incident on the array element and the direction of the array normal. Indicates the distance between adjacent array elements. This represents the difference in sound path from the far-field sound source to the second array element and to the reference array element (i.e., the third array element, i.e., the normal direction array element). Far-field noise sources include ships traveling on water, which radiate noise signals into the water. These noise signals are also broadband signals, and various noise interferences exist in the propagation medium. In this scheme, the array elements in the preset hydrophone array receive signals in a linear array configuration. In addition to receiving broadband signals reflected from directional targets, the array elements also receive broadband signals such as noise radiated from far-field noise sources through the propagation medium.

[0026] The expression for the underwater time-domain received signal pre-defined by the hydrophone array is: ; in, This refers to the number of array elements in the preset hydrophone array. In this scheme, the preset hydrophone array is a combination of... A uniform linear hydrophone array composed of 1000 array elements. Indicates the first The time-domain signal collected by the hydrophone contains both valid signal components and various noise signals from the environment.

[0027] The time-domain signal acquired by each array element can be... The frequency domain signals are obtained by performing Fast Fourier Transform on each array element, and the transformation results of all array elements and the time domain signals received by each array element are combined into a space-frequency cross-coupling matrix. This can be expressed as a formula: ; in, It is a Fast Fourier Transform. It is a space-frequency mutual coupling domain matrix. One dimension of the matrix represents different array elements, with each element representing a different spatial location. The other dimension represents the signal spectrum received by that element.

[0028] S102, determine the sound velocity of the medium in water and the spacing between adjacent elements of the preset hydrophone array respectively, and determine the desired spatial phase difference corresponding to the preset reference frequency based on the preset reference frequency, the sound velocity of the medium in water and the spacing between adjacent elements, so as to calculate the phase compensation factor.

[0029] The spacing between adjacent elements can be a fixed distance between the centers of two adjacent hydrophone elements in a preset uniform linear hydrophone array. The desired spatial phase difference can be the phase difference between the received signals of two adjacent elements when a signal of a preset reference frequency is incident on the preset hydrophone array under ideal error-free conditions. The phase difference is used to calculate the phase compensation factor in subsequent calculations.

[0030] In one embodiment, the sound velocity of the medium in water can be read, and the spacing between adjacent elements of a preset hydrophone array can be determined by reading preset hydrophone parameters. The desired spatial phase difference corresponding to the preset reference frequency can be calculated based on the preset desired spatial phase difference calculation formula, the preset reference frequency, the sound velocity of the medium in water, and the spacing between adjacent elements.

[0031] The preset formula for calculating the desired spatial phase difference is: ; in, It is the desired spatial phase difference. It is a preset reference frequency. It is the distance between adjacent array elements. It is the speed of sound in water.

[0032] S103, determine multiple compensation factors corresponding to the initial underwater received signal based on the desired spatial phase difference, and integrate the multiple compensation factors to obtain phase compensation information corresponding to the initial underwater received signal.

[0033] The compensation factor can be a phase calibration coefficient calculated individually for each signal receiving frequency of each element in the preset hydrophone array. The compensation factor can correct the broadband signal received by the preset hydrophone array. The phase compensation information in this scheme is a phase difference adaptation compensation factor matrix. The standard underwater received signal can be a signal whose spatial phase response of all frequency components has been equivalently mapped to a reference frequency. The standard underwater received signal has quasi-narrowband signal characteristics and can be directly used for subsequent covariance matrix calculation and robust weight solution.

[0034] In one embodiment, the compensation factors corresponding to the initial underwater received signals received by each element in the preset hydrophone array can be calculated according to the preset phase difference adaptation compensation factor calculation formula and the desired spatial phase difference. Then, multiple compensation factors are integrated in the form of a matrix according to the element positions to obtain the phase compensation information corresponding to the initial underwater received signal.

[0035] The formula for calculating the preset phase difference adaptation compensation factor is: ; in, It is a kind of based Interpolation compensation factor, It is the number of the spatial dimension of the array element. It is the desired spatial phase difference. yes function, It is a space-frequency mutual coupling domain matrix The frequency axis.

[0036] The formula for the phase difference adaptation compensation factor matrix is: ; in, It is along the spatial dimension A matrix formed by concatenating vectors.

[0037] The phase difference adaptation compensation factor matrix can be calculated using the formula described above. By splicing them together, we obtain the phase difference adaptation compensation factor matrix. and They are the same size and have the same frequency axis.

[0038] S104, based on phase compensation information, performs phase difference compensation correction on the initial underwater received signal in the space-frequency mutual coupling domain to obtain a standard underwater received signal, which is used for phase alignment in the space-frequency mutual coupling domain.

[0039] In one embodiment, the time-domain underwater received signal reported by the preset hydrophone array can be subjected to fast Fourier transform and spatial-frequency domain integration to obtain the initial underwater received signal in the spatial-frequency mutual coupling domain. A reference frequency is determined according to a preset processing frequency band. Based on the reference frequency and the phase compensation calculation formula, the phase difference adaptation compensation factor matrix corresponding to the initial underwater received signal of the preset hydrophone array is calculated. The Hadamard product of the phase difference adaptation compensation factor matrix and the signal matrix corresponding to the initial underwater received signal is calculated to obtain the phase correction result of the initial underwater received signal. The phase correction result of the initial underwater received signal is used as the standard underwater received signal, which is used for phase alignment in the spatial-frequency mutual coupling domain.

[0040] Phase difference can be adapted to the compensation factor matrix. , and the initial underwater received signal (space-frequency coupling domain matrix) By combining these, the phase difference compensation matrix in the space-frequency mutual coupling domain is obtained. Spatial-frequency mutual coupling domain phase difference compensation matrix The formula is: ; in, It is the element index in the preset hydrophone array. It is the phase difference compensation matrix in the space-frequency mutual coupling domain. It is a space-frequency mutual coupling domain matrix The Middle Each array element, frequency is The received signal data, It is the phase difference adaptation compensation factor matrix Zhongyu Phase difference adaptation compensation factor corresponding to the matrix position.

[0041] The aforementioned phase difference compensation matrix in the space-frequency mutual coupling domain The formula will adapt the phase difference to the compensation factor matrix. With the initial underwater received signal (space-frequency coupling domain matrix) Perform Hadamard multiplication calculations, and The elements at the same position in the matrix are multiplied element by element to obtain the compensated space-frequency mutual coupling domain matrix. Through this compensation, the broadband initial underwater received signal, which was originally diverging due to different frequencies, is realigned. All frequency components behave in the spatial domain as if they originate from the same reference frequency. This transforms the complex broadband beamforming problem into a more manageable equivalent narrowband signal processing problem, and eliminates the need for separate design for the scanning angle. Furthermore, it allows for the acquisition of the phase difference compensation matrix in the spatial-frequency mutual coupling domain. Robust adaptive beamforming can then be performed directly.

[0042] S105 calculates the standard covariance matrix of the standard underwater received signal and generates a steering vector uncertainty set based on the preset steering vector set parameters, which is used to calculate the broadband high-resolution robust beam weight.

[0043] The standard covariance matrix can be a matrix used to describe the statistical characteristics of the standard underwater received signal. It reflects the correlation between signals from different array elements and frequency points. The preset steering vector set parameters can be pre-set parameters used to define the range of steering vector deviation. These parameters may include the shape and radius parameters of the set. The steering vector uncertainty set can be a set containing all possible true steering vectors.

[0044] In one embodiment, the standard covariance matrix of the standard underwater received signal can be calculated according to a preset covariance matrix calculation formula, and a preset steering vector uncertainty set can be generated using a preset steering vector uncertainty set generation formula and preset steering vector set parameters. The steering vector uncertainty set is used for subsequent calculation of broadband high-resolution robust beam weights.

[0045] The default formula for calculating the covariance matrix is: ; in, It is the standard covariance matrix. This is the preset number of elements in the hydrophone array. yes The conjugate transpose of .

[0046] In one embodiment, the preset guidance vector set parameters include preset guidance vector set shape parameters and preset guidance vector set uncertainty radius; generating a guidance vector uncertainty set based on the preset guidance vector set parameters includes: determining the true guidance vector based on a standard underwater received signal, and determining the nominal guidance vector corresponding to the standard underwater received signal based on a preset reference frequency; calculating the guidance vector deviation between the true guidance vector and the nominal guidance vector, and generating a guidance vector uncertainty set based on the guidance vector deviation, the preset guidance vector set shape parameters, and the preset guidance vector set uncertainty radius.

[0047] The preset guide vector set shape parameter can be a parameter used to define the shape and deviation direction of the uncertainty set. In this scheme, the preset guide vector set shape parameter is a pre-set positive definite matrix. For simplified calculations, an identity matrix can be used, in which case the uncertainty set is spherical. The uncertainty radius of the preset steering vector set can be a parameter used to define the size of the uncertainty set, characterizing the maximum allowable deviation of the steering vector. The true steering vector can be a steering vector that truly reflects the direction of the received signal and the array state. The preset reference frequency can be a fixed frequency set in advance for phase calibration. In this scheme, the preset reference frequency is the center frequency of the processing band and is the core reference frequency for calculating the nominal steering vector. The nominal steering vector is the theoretical steering vector when the target signal propagates from the desired azimuth to the hydrophone array, assuming the hydrophone array has no errors, the signal propagation is interference-free, and the target azimuth is completely accurate. The nominal steering vector can be calculated based on the preset reference frequency; it is a calculable fixed value and is the center of the steering vector uncertainty set. The steering vector deviation can be the difference between the true steering vector and the nominal steering vector. The steering vector deviation reflects the degree of steering vector deviation caused by the actual environment or the array error of the preset hydrophone array.

[0048] In one embodiment, the true steering vector can be determined based on the signal direction or array state of the standard underwater received signal. The nominal steering vector corresponding to the standard underwater received signal is then calculated based on the steering vector calculation formula, a preset reference frequency, a preset spacing between adjacent elements in the hydrophone array, the sound velocity in the water, and a preset desired target direction. The difference between the true and nominal steering vectors is calculated to obtain the steering vector deviation. Finally, a steering vector uncertainty set is generated based on a preset steering vector uncertainty set expression, the steering vector deviation, the preset steering vector set shape parameters, and the preset steering vector set uncertainty radius.

[0049] The expression for the predefined uncertainty set of the guide vector is: ; in, It is the uncertain set of steering vectors, including all possible true steering vectors. It is the actual guide vector. It is the nominal guide vector. It is a positive definite matrix, that is, the shape parameter of the aforementioned preset guide vector set. It is the radius of uncertainty of the preset guide vector set. It is the number of array elements.

[0050] To simplify calculations, the positive definite matrix can be... Take the identity matrix; in this case, the set is spherical. It is the signal steering vector for a uniform linear array.

[0051] The core logic of the pre-defined guide vector uncertainty set is the true guide vector. It will not deviate from the nominal steering vector If it's too far, the deviation range is determined by the positive definite matrix. Uncertainty radius of the set of pre-defined guiding vectors Common constraints are the core model for achieving robustness in beamforming.

[0052] S106. Based on the preset optimal receiving beam weight constraint formula, standard covariance matrix and steering vector uncertainty set, determine the optimal underwater receiving beam weight vector corresponding to the preset hydrophone array, which is used to adjust the receiving coefficient of the preset hydrophone array.

[0053] The optimal underwater receiving beamweight vector can be a weight vector that enables the preset hydrophone array to achieve optimal target signal focusing and interference or noise suppression. The receiving coefficients can be the receiving gain coefficient and phase compensation coefficient of each element in the preset hydrophone array. The magnitude of each element in the optimal underwater receiving beamweight vector corresponds to the receiving gain of the array element, and the phase corresponds to the phase compensation of the array element. Adjusting the receiving coefficients essentially loads the instructions of the weight vector onto the array elements, optimizing the spatial receiving characteristics of the array.

[0054] In one embodiment, the optimal underwater receiving beam weight vector corresponding to the preset hydrophone array can be calculated according to the preset optimal receiving beam weight limit formula, the standard covariance matrix, and the steering vector uncertainty set. By adjusting the receiving coefficient of the preset hydrophone array with the optimal underwater receiving beam weight vector, the preset hydrophone array can achieve the function of focusing the optimal target signal and suppressing interference or noise signals.

[0055] S107: When the current received signals of each preset scanning direction received by the preset hydrophone array after the receiving coefficient adjustment are read, the received signal strength of each preset scanning direction is determined, and broadband high-resolution robust beam orientation is performed based on multiple signal strengths to form an underwater broadband high-resolution robust beam.

[0056] The preset scanning direction can be multiple discrete azimuth angles that are pre-set to cover the target azimuth space. The currently received signal can be the signal actually received in a certain preset scanning direction after the preset hydrophone array has been loaded with receiving coefficients. The received signal strength can be the beam output power of the beam corresponding to the received signal. The underwater broadband high-resolution robust beam can be the acoustic receiving beam formed by the preset hydrophone array through a specific algorithm that weights and synthesizes broadband acoustic signals from different directions underwater. The underwater broadband high-resolution robust beam has the characteristics of high-resolution target resolution and anti-interference or mismatch robustness in the field of underwater acoustic signal processing. It can accurately locate underwater targets.

[0057] In one embodiment, when the preset hydrophone array is loaded with a receiving coefficient and receives and reports the current received signal in each preset scanning direction, the received signal strength in each preset scanning direction can be calculated based on the receiving coefficient and the steering vector of the received signal. The azimuth angle with the largest signal strength among multiple signal strengths is determined, and this azimuth angle is taken as the direction corresponding to the highest resolution and most stable beam in the broadband signal, thus forming an underwater broadband high-resolution robust beam.

[0058] In one embodiment, after determining the received signal strength in each preset scanning direction and performing broadband high-resolution robust beam orientation based on multiple signal strengths to form an underwater broadband high-resolution robust beam, the method further includes: calculating the received signal strength in each scanning direction according to the optimal underwater received beam weight vector and the current steering vector in the current received signal; integrating the received signal strengths in all scanning directions according to the azimuth sequence corresponding to each scanning direction to generate an underwater target azimuth spectrum; extracting the azimuth corresponding to the peak signal strength in the underwater target azimuth spectrum for broadband high-resolution robust beam orientation to obtain the underwater target orientation result.

[0059] The azimuth sequence can represent the order in which the azimuth angles corresponding to each preset scanning direction are scanned. The underwater target azimuth spectrum can be a signal distribution map formed by using the azimuth sequence as the abscissa and the received signal strength as the ordinate. The underwater target azimuth spectrum visually presents the signal energy distribution of the preset hydrophone array at different azimuth angles, and the target direction will show obvious power peaks due to signal focusing.

[0060] In one embodiment, the received signal strength in each scanning direction can be calculated based on a preset signal output power calculation formula, the optimal underwater receiving beam weight vector, and the current steering vector in the currently received signal. Then, according to the azimuth sequence corresponding to each scanning direction, with the azimuth sequence as the x-axis and the received signal strength as the y-axis, the received signal strengths in all scanning directions are integrated to generate an underwater target azimuth spectrum. The azimuth angle corresponding to the peak signal strength in the underwater target azimuth spectrum is identified, and the azimuth angle with the highest peak is taken as the broadband high-resolution robust beamdirection result, forming an underwater broadband high-resolution robust beam.

[0061] This scheme calculates the received signal strength in each scanning direction, integrates the received signal strength in all scanning directions according to the azimuth sequence corresponding to each scanning direction, generates an underwater target azimuth spectrum, and forms an underwater broadband high-resolution robust beam, which can improve the accuracy of the underwater broadband high-resolution robust beamforming results.

[0062] Figure 3 This is a schematic diagram of a broadband high-resolution beam spatial spectrum simulation provided in an embodiment of this application. Figure 3 As shown in the figure, the spatial spectrum of conventional time-domain beamforming, the spatial spectrum of conventional time-domain beamforming after phase difference compensation, and the spatial spectrum of robust beamforming after phase difference compensation are included. The horizontal axis represents the azimuth angle of the received signal, and the vertical axis represents the normalized energy value of the received signal at each azimuth angle.

[0063] The specific parameters of the simulation environment are: sound speed 1500m / s, number of physical array elements 32, array element spacing 0.9m, sampling frequency 6000Hz, and signal frequency 1000Hz.

[0064] Based on the above simulation conditions, the performance of the broadband high-resolution robust beamforming method SFWRB (Space-Frequency Wideband Robust Beamforming) based on space-frequency mutual coupling domain phase difference compensation is analyzed, and compared with the traditional time-domain beamforming algorithm and the traditional time-domain beamforming algorithm after mutual coupling domain phase difference compensation, generating the above schematic diagram.

[0065] In terms of background noise suppression, traditional time-domain beamforming algorithms without mutual-domain phase difference compensation have the highest background noise level, with an overall spectral level above -15dB, indicating limited interference suppression capabilities. Traditional time-domain beamforming algorithms with mutual-domain phase difference compensation exhibit a finer main lobe, demonstrating the effectiveness of phase alignment in focusing broadband signal energy. Furthermore, the broadband high-resolution robust beamforming method SFWRB based on spatial-frequency mutual-domain phase difference compensation proposed in this invention further reduces the background noise level to below -25dB, exhibiting optimal noise and interference suppression performance.

[0066] In terms of main lobe resolution and azimuth estimation accuracy, traditional time-domain beamforming has the widest main lobe, making it difficult to accurately distinguish nearby signals. Traditional time-domain beamforming with mutual coupling domain compensation narrows the main lobe somewhat. In contrast, the broadband high-resolution robust beamforming method based on spatial-frequency mutual coupling domain phase difference compensation of this invention generates the narrowest and sharpest main lobe, exhibiting the strongest spatial resolution and enabling more precise orientation of the signal source's azimuth angle.

[0067] Simulation results show that phase difference compensation in the space-frequency mutual coupling domain is fundamental to improving broadband beamforming performance. It directly solves the multi-frequency component problem in broadband signal processing and effectively narrows the main lobe width. In this scheme, phase difference compensation and robust beamforming work synergistically. Phase compensation provides an energy-aligned "quasi-narrowband" signal for subsequent processing, while robust beamforming based on uncertainty sets further enhances the system's interference suppression and signal fidelity under non-ideal conditions.

[0068] This scheme simultaneously achieves lower background noise level, narrower main lobe width, and higher azimuth resolution in the output spatial spectrum. Its overall performance is significantly better than traditional time-domain beamforming and its improved algorithm that only performs phase compensation. The technical solution provided in this application embodiment acquires the underwater time-domain received signal received by a preset hydrophone array, and converts the underwater time-domain received signal to the space-frequency mutual coupling domain according to a preset frequency domain conversion algorithm to obtain an initial underwater received signal for phase difference compensation in the mutual coupling domain; it determines the sound velocity of the medium in water and the spacing between adjacent array elements of the preset hydrophone array, and determines the desired spatial phase difference corresponding to the preset reference frequency based on the preset reference frequency, the sound velocity of the medium in water, and the spacing between adjacent array elements, for calculating the phase compensation factor; it determines multiple compensation factors corresponding to the initial underwater received signal based on the desired spatial phase difference, and integrates the multiple compensation factors to obtain phase compensation information corresponding to the initial underwater received signal; and it performs phase difference compensation on the initial underwater received signal in the space-frequency mutual coupling domain based on the phase compensation information. The process involves several steps: First, a standard underwater received signal is obtained and used for phase alignment in the space-frequency inter-coupling domain. Then, the standard covariance matrix of the standard underwater received signal is calculated, and a steering vector uncertainty set is generated based on preset steering vector set parameters. This uncertainty set is used to calculate the broadband high-resolution robust beam weight. Based on the preset optimal receiving beam weight constraint formula, the standard covariance matrix, and the steering vector uncertainty set, the optimal underwater receiving beam weight vector corresponding to the preset hydrophone array is determined and used to adjust the receiving coefficients of the preset hydrophone array. Finally, when the current received signal in each preset scanning direction is read from the preset hydrophone array after adjustment based on the receiving coefficients, the received signal strength in each preset scanning direction is determined. Based on multiple signal strengths, broadband high-resolution robust beam orientation is performed to form an underwater broadband high-resolution robust beam. The above-described broadband high-resolution robust beamforming method based on spatial-frequency mutual coupling domain phase difference compensation solves the problems of poor anti-interference capability and low direction finding accuracy in related technologies. By determining phase compensation information to correct the initial underwater received signal, a standard underwater received signal is obtained. The optimal underwater received beam weight vector corresponding to the preset hydrophone array is determined, and an underwater broadband high-resolution robust beam is formed according to the received signal strength in each preset scanning direction. This achieves full-band phase difference compensation for the underwater received signal, ensuring the reception of the target signal while stabilizing and suppressing interference signals. This improves the anti-interference capability of the underwater broadband high-resolution robust beam, thereby improving the accuracy of the underwater direction finding results.

[0069] Figure 4 This is a flowchart illustrating the determination of the optimal underwater receiving beam weight vector for a preset hydrophone array, provided in an embodiment of this application. For example... Figure 4 As shown, the specific steps include the following: S401, based on the first correlation between the preset covariance matrix and the received beam weight, the standard covariance matrix, the second correlation between the preset steering vector and the received beam weight, and the nominal steering vector in the steering vector uncertainty set, constructs the received beam weight optimization formula. The nominal steering vector is the theoretical steering vector corresponding to the standard underwater received signal determined based on the preset reference frequency.

[0070] The first correlation between the preset covariance matrix and the received beam weights can be an energy mapping relationship between the covariance matrix and the received beam weight vector. This first correlation quantifies the total noise power through a quadratic combination of the received beam weights. The second correlation between the preset steering vector and the received beam weights can be a constraint relationship between the steering vector and the received beam weight vector. This second correlation indicates that the weight vector must satisfy a specific matching condition with the nominal steering vector to ensure the target signal passes through without distortion.

[0071] In one embodiment, a noise optimization function can be constructed using a first correlation. This function adjusts the weight vector to maximize the suppression of noise or interference signal energy from non-target directions by a pre-defined hydrophone array. A steering vector constraint function can be constructed using a second correlation. This function limits the adjustment range of the weight vector, preventing the target signal from being attenuated or canceled out due to excessive noise suppression.

[0072] The formula for optimizing the receiving beam weight is:

[0073] in, It is about minimizing noise power, that is, suppressing interference and noise to the greatest extent possible. It is the optimal underwater receiving beam weight. It is the noise covariance matrix, based on the standard covariance matrix mentioned above. Sure, This is to ensure that the gain of the receiving beam in the direction of the desired signal is 1 (0 dB), that is, the signal is not attenuated and the desired signal passes through without distortion.

[0074] S402, calculate the optimal underwater receiving beam weight vector corresponding to the preset hydrophone array according to the preset optimal receiving beam weight limit formula and the receiving beam weight optimization formula.

[0075] In one embodiment, the weight range corresponding to each vector element in the initial receiving beam weight vector can be calculated according to the receiving beam weight optimization formula, and the weight range corresponding to each vector element can be filtered according to the preset optimal receiving beam weight limitation formula to obtain the optimal underwater receiving beam weight vector corresponding to the preset hydrophone array.

[0076] In one embodiment, the optimal underwater receiving beamweight vector corresponding to a preset hydrophone array is calculated according to a preset optimal receiving beamweight constraint formula and a receiving beamweight optimization formula. This includes: constructing a Lagrange equation associated with the nominal steering vector and the receiving beamweight based on the receiving beamweight optimization formula, and calculating the optimal Lagrange multipliers according to the Lagrange equation; and calculating the optimal underwater receiving beamweight vector corresponding to the preset hydrophone array according to the preset optimal receiving beamweight constraint formula, the nominal steering vector, the standard covariance matrix, and the optimal Lagrange multipliers.

[0077] The Lagrange equations associated with the nominal steering vector and the receiving beam weights can be mathematical equations that integrate the noise optimization function and the steering vector constraint function into an unconstrained optimization problem. By introducing Lagrange multipliers, the constrained optimization objective is transformed into a directly solvable scalar equation. Based on the noise optimization function, the steering vector constraints are embedded within the Lagrange multipliers, forming an equation that simultaneously includes the nominal steering vector, the receiving beam weights, and the Lagrange multipliers. The optimal Lagrange multiplier is the Lagrange multiplier that enables the Lagrange equation to reach its extremum. The optimal Lagrange multiplier is the weight adjustment coefficient connecting the constraints and the optimization objective, determining the relative importance of the constraints and the optimization objective. The optimal value is obtained by solving the extremum conditions of the Lagrange equation.

[0078] In one embodiment, the receive beamweight optimization formula can be used as a construction condition to construct a Lagrange equation associated with the nominal steering vector and the receive beamweight. By solving the extrema of the Lagrange equation, the optimal Lagrange multiplier corresponding to the extrema is obtained. Based on the correspondence between the reference frequency and the nominal steering vector, and a preset reference frequency, the nominal steering vector corresponding to the standard underwater received signal is calculated. The nominal steering vector, the standard covariance matrix, and the optimal Lagrange multiplier are then substituted into the preset optimal receive beamweight constraint formula to calculate the optimal underwater receive beamweight vector corresponding to the preset hydrophone array.

[0079] By constructing a Lagrange function, the problem of finding the optimal underwater receiver beam weight vector can be transformed into solving the problem with respect to the Lagrange multipliers. The equation. Solve for the Lagrange multipliers. The equation is: ; in, These are Lagrange multipliers, representing the weighting factors of the constraints. It is the covariance matrix The 1 eigenvalue, It is to guide a linear matrix to a vector. Projected onto a positive definite matrix The first eigenvector basis One portion, It is the radius of the uncertain set of the guiding vector.

[0080] Lagrange multipliers The formula for limiting the feasible range of values ​​is: ; In the formula, It is a linear matrix guiding vector. norm, It is the covariance matrix The largest eigenvalue, It is the covariance matrix The minimum eigenvalue. After solving for a suitable... Then, by substituting it back into the preset optimal receiving beam weight constraint formula, the optimal underwater receiving beam weight vector that is robust to steering vector mismatch can be calculated. .

[0081] In one embodiment, the preset optimal receive beam weight constraint formula is: ; in, It is the optimal underwater receiving beam weight vector. It is the standard covariance matrix, It is the optimal Lagrange multiplier. It is the nominal guide vector. It is the symbol for the conjugate transpose. It is an identity matrix.

[0082] Optimal underwater receiving beam weight vector It can effectively suppress the performance degradation caused by steering vector error and improve the robustness of the system in real-world environments.

[0083] This scheme calculates the optimal receiving beam weight vector by pre-setting an optimal receiving beam weight constraint formula, which can effectively improve the efficiency of calculating the optimal receiving beam weight vector and the accuracy of the calculation results.

[0084] The technical solution provided in this application embodiment constructs a receiving beam weight optimization formula, calculates the optimal underwater receiving beam weight vector corresponding to the preset hydrophone array based on the preset optimal receiving beam weight constraint formula and the receiving beam weight optimization formula, and achieves the purpose of determining the receiving beam weight by combining noise optimization and vector constraints. This improves the target signal receiving power while suppressing noise and enhances the rationality of the optimal underwater receiving beam weight vector.

[0085] The technical solution provided in this application converts the underwater time-domain received signal from a preset hydrophone array to the spatial-frequency mutual coupling domain according to a preset frequency-domain conversion algorithm to obtain an initial underwater received signal for mutual coupling domain phase difference compensation. Based on a preset reference frequency, the sound velocity of the medium in water, and the spacing between adjacent array elements, the desired spatial-frequency phase difference corresponding to the preset reference frequency is determined for calculating a phase compensation factor. Then, based on the desired spatial-frequency phase difference, multiple compensation factors corresponding to the initial underwater received signal are determined, resulting in phase compensation information corresponding to the initial underwater received signal. This achieves the goal of determining the phase compensation information of the received signal based on multiple influencing factors of the spatial-frequency mutual coupling domain phase deviation of the received signal, thus improving the accuracy of the phase compensation information.

[0086] Figure 5 This is a structural block diagram of a broadband high-resolution robust beamforming device based on spatial-frequency mutual coupling domain phase difference compensation provided in an embodiment of this application. Figure 5 As shown, it specifically includes the following: The signal conversion module 501 is used to acquire the underwater time-domain received signal received by the preset hydrophone array, and convert the underwater time-domain received signal to the space-frequency mutual coupling domain according to the preset frequency domain conversion algorithm to obtain the initial underwater received signal for mutual coupling domain phase difference compensation. The spatial phase difference determination module 502 is used to determine the sound velocity of the medium in water and the spacing between adjacent elements of the preset hydrophone array, respectively. Based on the preset reference frequency, the sound velocity of the medium in water and the spacing between adjacent elements, the desired spatial phase difference corresponding to the preset reference frequency is determined and used to calculate the phase compensation factor. The compensation information determination module 503 is used to determine multiple compensation factors corresponding to the initial underwater received signal based on the desired spatial phase difference, and integrate the multiple compensation factors to obtain phase compensation information corresponding to the initial underwater received signal. Phase correction module 504 is used to perform phase difference compensation correction on the initial underwater received signal in the space-frequency mutual coupling domain based on phase compensation information to obtain a standard underwater received signal for phase alignment in the space-frequency mutual coupling domain. The covariance matrix calculation module 505 is used to calculate the standard covariance matrix of the standard underwater received signal. The set generation module 506 is used to generate an uncertain set of guide vectors based on preset guide vector set parameters; The weight vector determination module 507 is used to determine the optimal underwater receiving beam weight vector corresponding to the preset hydrophone array based on the preset optimal receiving beam weight constraint formula, standard covariance matrix and steering vector uncertainty set, and is used to adjust the receiving coefficient of the preset hydrophone array. The beamforming module 508 is used to determine the received signal strength of each preset scanning direction when the current received signal of each preset scanning direction is read from the preset hydrophone array after the receiving coefficient is adjusted, and to perform broadband high-resolution robust beam orientation based on multiple signal strengths to form an underwater broadband high-resolution robust beam.

[0087] Furthermore, the weight vector determination module 507 is specifically used for: Based on the first correlation between the preset covariance matrix and the received beam weight, the standard covariance matrix, the second correlation between the preset steering vector and the received beam weight, and the nominal steering vector in the uncertainty set of the steering vector, an optimization formula for the received beam weight is constructed. The nominal steering vector is a theoretical steering vector corresponding to the standard underwater received signal, determined based on the preset reference frequency. Based on the preset optimal receiving beam weight constraint formula and the receiving beam weight optimization formula, calculate the optimal underwater receiving beam weight vector corresponding to the preset hydrophone array.

[0088] Furthermore, the weight vector determination module 507 is specifically used for: Based on the receive beam weight optimization formula, a Lagrange equation associated with the nominal steering vector and the receive beam weight is constructed, and the optimal Lagrange multiplier is calculated according to the Lagrange equation. Based on the preset optimal receiving beam weight constraint formula, nominal steering vector, standard covariance matrix, and optimal Lagrange multipliers, calculate the optimal underwater receiving beam weight vector corresponding to the preset hydrophone array.

[0089] Furthermore, the preset optimal receiving beam weight constraint formula is as follows: ; in, It is the optimal underwater receiving beam weight vector. It is the standard covariance matrix, It is the optimal Lagrange multiplier. It is the nominal guide vector. It is the symbol for the conjugate transpose. It is an identity matrix.

[0090] Furthermore, the preset guide vector set parameters include the preset guide vector set shape parameters and the preset guide vector set uncertainty radius; Set generation module 506 is specifically used for: The actual steering vector is determined based on the standard underwater received signal, and the nominal steering vector corresponding to the standard underwater received signal is determined based on the preset reference frequency. Calculate the deviation between the actual and nominal guidance vectors, and generate an uncertainty set of guidance vectors based on the deviation, the shape parameters of the preset guidance vector set, and the uncertainty radius of the preset guidance vector set.

[0091] Furthermore, the beamforming module 508 is also used for: The received signal strength in each scanning direction is calculated based on the optimal underwater receiving beam weight vector and the current steering vector in the current received signal. Based on the azimuth sequence corresponding to each scanning direction, the received signal strength of all scanning directions is integrated to generate an underwater target azimuth spectrum; By extracting the azimuth angle corresponding to the peak signal intensity in the underwater target's azimuth spectrum and performing broadband high-resolution robust beamforming, the underwater target orientation result is obtained.

[0092] The technical solution provided in this application includes a signal conversion module for acquiring the underwater time-domain received signal received by a preset hydrophone array and converting it to the space-frequency mutual coupling domain according to a preset frequency-domain conversion algorithm to obtain an initial underwater received signal for phase difference compensation in the mutual coupling domain; a space-frequency phase difference determination module for determining the underwater medium sound velocity and the spacing between adjacent elements of the preset hydrophone array, and determining the desired space-frequency phase difference corresponding to the preset reference frequency based on the preset reference frequency, the underwater medium sound velocity, and the spacing between adjacent elements, for calculating the phase compensation factor; a compensation information determination module for determining multiple compensation factors corresponding to the initial underwater received signal based on the desired space-frequency phase difference, and integrating the multiple compensation factors to obtain phase compensation information corresponding to the initial underwater received signal; and a phase correction module for correcting the initial underwater received signal in the space-frequency mutual coupling domain based on the phase compensation information. The system performs phase difference compensation correction to obtain a standard underwater received signal for phase alignment in the space-frequency mutual coupling domain; a covariance matrix calculation module calculates the standard covariance matrix of the standard underwater received signal; an ensemble generation module generates a steering vector uncertainty set based on preset steering vector ensemble parameters; a weight vector determination module determines the optimal underwater received beam weight vector corresponding to the preset hydrophone array based on the preset optimal received beam weight constraint formula, the standard covariance matrix, and the steering vector uncertainty set, for adjusting the receiving coefficients of the preset hydrophone array; and a beamforming module, upon reading the current received signal in each preset scanning direction received by the preset hydrophone array after adjustment based on the receiving coefficients, determines the received signal strength in each preset scanning direction, and performs broadband high-resolution robust beam orientation based on multiple signal strengths to form an underwater broadband high-resolution robust beam. The aforementioned broadband high-resolution robust beamforming device based on spatial-frequency mutual coupling domain phase difference compensation solves the problems of poor anti-interference capability and low direction-finding accuracy in related technologies. By determining the phase compensation information to correct the initial underwater received signal, a standard underwater received signal is obtained. The optimal underwater received beam weight vector corresponding to the preset hydrophone array is determined, and an underwater broadband high-resolution robust beam is formed according to the received signal strength in each preset scanning direction. This achieves the purpose of full-band phase difference compensation for the underwater received signal, ensuring the reception of the target signal while stabilizing and suppressing interference signals. This improves the anti-interference capability of the underwater broadband high-resolution robust beam and thus improves the accuracy of the underwater direction-finding results.

[0093] The broadband high-resolution robust beamforming system based on space-frequency mutual coupling domain phase difference compensation, as described in this application, can be configured in a device, or as a component, integrated circuit, or chip in a terminal. This system can be configured in mobile electronic devices or non-mobile electronic devices. For example, mobile electronic devices can be mobile phones, tablets, laptops, PDAs, in-vehicle electronic devices, wearable devices, ultra-mobile personal computers (UMPCs), netbooks, or personal digital assistants (PDAs), etc., while non-mobile electronic devices can be servers, network-attached storage (NAS), personal computers (PCs), televisions (TVs), ATMs, or self-service machines, etc. This application does not impose specific limitations.

[0094] The broadband high-resolution robust beamforming system based on spatial-frequency mutual coupling domain phase difference compensation in this application embodiment can be an operating system. This operating system can be Android, iOS, or other possible operating systems; this application embodiment does not specifically limit it.

[0095] The broadband high-resolution robust beamforming system based on spatial-frequency mutual coupling domain phase difference compensation provided in this application embodiment can realize the various processes implemented in the above-mentioned method embodiments. To avoid repetition, it will not be described again here.

[0096] like Figure 6 As shown, this application embodiment also provides an electronic device 600, including a processor 601, a memory 602, and a program or instructions stored in the memory 602 and executable on the processor 601. When the program or instructions are executed by the processor 601, they implement the various processes of the above-described embodiment of a broadband high-resolution robust beamforming method based on spatial frequency mutual coupling domain phase difference compensation, and can achieve the same technical effect. To avoid repetition, they will not be described again here.

[0097] It should be noted that the electronic devices in the embodiments of this application include the mobile electronic devices and non-mobile electronic devices described above.

[0098] This application also provides a readable storage medium storing a program or instructions. When the program or instructions are executed by a processor, they implement the various processes of the above-described embodiment of a broadband high-resolution robust beamforming method based on spatial-frequency mutual coupling domain phase difference compensation, and can achieve the same technical effect. To avoid repetition, they will not be described again here.

[0099] The processor is the processor in the electronic device described in the above embodiments. The readable storage medium includes computer-readable storage media, such as computer read-only memory (ROM), random access memory (RAM), magnetic disk, or optical disk.

[0100] This application also provides a program product including program code. When the program product is run on a computer device, the program code causes the computer device to perform the steps of the methods described above according to various exemplary embodiments of this application. For example, the computer device can execute a broadband high-resolution robust beamforming method based on space-frequency mutual coupling domain phase difference compensation as described in an embodiment of this application. The program product can be implemented using any combination of one or more readable media.

[0101] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or system that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or system. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or system that includes that element. Furthermore, it should be noted that the scope of the methods and systems in the embodiments of this application is not limited to performing functions in the order shown or discussed, but may also include performing functions substantially simultaneously or in the reverse order, depending on the functions involved. For example, the described methods may be performed in a different order than described, and various steps may be added, omitted, or combined. Additionally, features described with reference to certain examples may be combined in other examples.

[0102] Through the above description of the embodiments, those skilled in the art can clearly understand that the methods of the above embodiments can be implemented by means of software plus necessary general-purpose hardware platforms. Of course, they can also be implemented by hardware, but in many cases the former is a better implementation method. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the related technology, can be embodied in the form of a computer software product. This computer software product is stored in a storage medium (such as ROM / RAM, magnetic disk, optical disk) and includes several instructions to cause a terminal (which may be a mobile phone, computer, server, or network device, etc.) to execute the methods described in the various embodiments of this application.

[0103] The embodiments of this application have been described above with reference to the accompanying drawings. However, this application is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many other forms under the guidance of this application without departing from the spirit and scope of the claims, and all of these forms are within the protection scope of this application.

[0104] The above description is merely a preferred embodiment and the technical principles employed in this application. This application is not limited to the specific embodiments described herein, and various obvious changes, readjustments, and substitutions that can be made by those skilled in the art will not depart from the scope of protection of this application. Therefore, although this application has been described in detail through the above embodiments, this application is not limited to the above embodiments, and may include more other equivalent embodiments without departing from the concept of this application, the scope of which is determined by the scope of the claims.

Claims

1. A broadband, high-resolution, robust beamforming method based on space-frequency mutual coupling domain phase difference compensation, characterized in that, The method includes: The underwater time-domain received signal received by the preset hydrophone array is acquired, and the underwater time-domain received signal is converted to the space-frequency mutual coupling domain according to the preset frequency domain conversion algorithm to obtain the initial underwater received signal, which is used for mutual coupling domain phase difference compensation. The sound velocity of the medium in water and the spacing between adjacent elements of the preset hydrophone array are determined respectively. The desired spatial phase difference corresponding to the preset reference frequency is determined based on the preset reference frequency, the sound velocity of the medium in water and the spacing between adjacent elements, and is used to calculate the phase compensation factor. Based on the desired spatial phase difference, multiple compensation factors corresponding to the initial underwater received signal are determined, and the multiple compensation factors are integrated to obtain phase compensation information corresponding to the initial underwater received signal. Based on the phase compensation information, the initial underwater received signal in the space-frequency mutual coupling domain is phase difference compensated and corrected to obtain a standard underwater received signal, which is used for phase alignment in the space-frequency mutual coupling domain. The standard covariance matrix of the standard underwater received signal is calculated, and a steering vector uncertainty set is generated according to the preset steering vector set parameters, which is used to calculate the broadband high-resolution robust beam weight. Based on the preset optimal receiving beam weight constraint formula, the standard covariance matrix, and the steering vector uncertainty set, the optimal underwater receiving beam weight vector corresponding to the preset hydrophone array is determined, which is used to adjust the receiving coefficient of the preset hydrophone array. Upon reading the current received signals of each preset scanning direction received by the preset hydrophone array after adjustment based on the receiving coefficient, the received signal strength of each preset scanning direction is determined, and broadband high-resolution robust beam orientation is performed based on multiple signal strengths to form an underwater broadband high-resolution robust beam.

2. The broadband high-resolution robust beamforming method based on spatial-frequency mutual coupling domain phase difference compensation according to claim 1, characterized in that, The step of determining the optimal underwater receiving beam weight vector corresponding to the preset hydrophone array based on the preset optimal receiving beam weight constraint formula, the standard covariance matrix, and the steering vector uncertainty set includes: Based on the first correlation between the preset covariance matrix and the received beam weight, the standard covariance matrix, the second correlation between the preset steering vector and the received beam weight, and the nominal steering vector in the uncertainty set of the steering vector, a formula for optimizing the received beam weight is constructed. The nominal steering vector is a theoretical steering vector corresponding to the standard underwater received signal, determined based on the preset reference frequency. Based on the preset optimal receiving beam weight constraint formula and the receiving beam weight optimization formula, the optimal underwater receiving beam weight vector corresponding to the preset hydrophone array is calculated.

3. The broadband high-resolution robust beamforming method based on spatial-frequency mutual coupling domain phase difference compensation according to claim 2, characterized in that, The step of calculating the optimal underwater receiving beam weight vector corresponding to the preset hydrophone array according to the preset optimal receiving beam weight constraint formula and the receiving beam weight optimization formula includes: Based on the received beam weight optimization formula, a Lagrange equation associated with the nominal steering vector and the received beam weight is constructed, and the optimal Lagrange multiplier is calculated according to the Lagrange equation. The optimal underwater receiving beam weight vector corresponding to the preset hydrophone array is calculated based on the preset optimal receiving beam weight limit formula, the nominal steering vector, the standard covariance matrix, and the optimal Lagrange multiplier.

4. The broadband high-resolution robust beamforming method based on spatial-frequency mutual coupling domain phase difference compensation according to claim 3, characterized in that, The preset optimal receiving beam weight constraint formula is as follows: ； in, It is the optimal underwater receiving beam weight vector. It is the standard covariance matrix, It is the optimal Lagrange multiplier. It is the nominal guide vector. It is the symbol for the conjugate transpose. It is an identity matrix.

5. The broadband high-resolution robust beamforming method based on spatial-frequency mutual coupling domain phase difference compensation according to claim 1, characterized in that, The preset guide vector set parameters include the preset guide vector set shape parameters and the preset guide vector set uncertainty radius; The step of generating an uncertain set of guide vectors based on preset guide vector set parameters includes: The actual steering vector is determined based on the standard underwater received signal, and the nominal steering vector corresponding to the standard underwater received signal is determined based on the preset reference frequency. Calculate the guidance vector deviation between the actual guidance vector and the nominal guidance vector, and generate a guidance vector uncertainty set based on the guidance vector deviation, the shape parameters of the preset guidance vector set, and the uncertainty radius of the preset guidance vector set.

6. The broadband high-resolution robust beamforming method based on spatial-frequency mutual coupling domain phase difference compensation according to claim 1, characterized in that, After determining the received signal strength in each of the preset scanning directions and performing broadband high-resolution robust beam orientation based on multiple signal strengths to form an underwater broadband high-resolution robust beam, the method further includes: The received signal strength in each scanning direction is calculated based on the optimal underwater receiving beam weight vector and the current steering vector in the current received signal. Based on the azimuth sequence corresponding to each scanning direction, the received signal strength of all scanning directions is integrated to generate an underwater target azimuth spectrum; The azimuth angle corresponding to the peak signal intensity in the underwater target azimuth spectrum is extracted for broadband high-resolution robust beamforming to obtain the underwater target orientation result.

7. A broadband high-resolution robust beamforming device based on spatial-frequency mutual coupling domain phase difference compensation, characterized in that, The device includes: The signal conversion module is used to acquire the underwater time-domain received signal received by the preset hydrophone array, and convert the underwater time-domain received signal to the space-frequency mutual coupling domain according to the preset frequency domain conversion algorithm to obtain the initial underwater received signal for mutual coupling domain phase difference compensation. The spatial phase difference determination module is used to determine the sound velocity of the medium in water and the spacing between adjacent array elements of the preset hydrophone array, respectively. Based on the preset reference frequency, the sound velocity of the medium in water and the spacing between adjacent array elements, the desired spatial phase difference corresponding to the preset reference frequency is determined and used to calculate the phase compensation factor. The compensation information determination module is used to determine multiple compensation factors corresponding to the initial underwater received signal based on the desired spatial phase difference, and integrate the multiple compensation factors to obtain phase compensation information corresponding to the initial underwater received signal. The phase correction module is used to perform phase difference compensation correction on the initial underwater received signal in the space-frequency mutual coupling domain based on the phase compensation information to obtain a standard underwater received signal for phase alignment in the space-frequency mutual coupling domain. The covariance matrix calculation module is used to calculate the standard covariance matrix of the standard underwater received signal. The set generation module is used to generate a guide vector uncertainty set based on preset guide vector set parameters, which is used to calculate broadband high-resolution robust beam weights; The weight vector determination module is used to determine the optimal underwater receiving beam weight vector corresponding to the preset hydrophone array based on the preset optimal receiving beam weight limit formula, the standard covariance matrix and the steering vector uncertainty set, and to adjust the receiving coefficient of the preset hydrophone array. The beamforming module is used to determine the received signal strength of each preset scanning direction when the current received signal of each preset scanning direction is read from the preset hydrophone array after adjustment based on the receiving coefficient, and to perform broadband high-resolution robust beam orientation based on multiple signal strengths to form an underwater broadband high-resolution robust beam.

8. An electronic device, characterized in that, It includes a processor, a memory, and a program or instructions stored in the memory and running on the processor, wherein when the program or instructions are executed by the processor, they implement the steps of the broadband high-resolution robust beamforming method based on spatial-frequency mutual coupling domain phase difference compensation as described in any one of claims 1-6.

9. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a program or instructions that, when executed by a processor, implement the steps of the broadband high-resolution robust beamforming method based on spatial-frequency mutual coupling domain phase difference compensation as described in any one of claims 1-6.

10. A computer program product, characterized in that, The computer program product includes a computer program stored in a computer-readable storage medium. When at least one processor of the electronic device reads and executes the computer program from the computer-readable storage medium, it implements the steps of the broadband high-resolution robust beamforming method based on spatial-frequency mutual coupling domain phase difference compensation as described in any one of claims 1-6.

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