A constant beamwidth adaptive beamforming method and system based on frequency difference

Abstract

The application discloses a constant beam adaptive beam forming method and system based on frequency difference, and the method comprises the following steps: segmenting FFT of time domain data of a target signal, converting the time domain data into frequency domain data, and calculating a data covariance matrix for each frequency point; estimating the azimuth of the target by using the data covariance matrix of each frequency point to obtain an estimated value of the target azimuth; generating a Gaussian random sequence with the same length as the array receiving signal as a reference signal, and reconstructing the array output of the reference signal according to the target azimuth estimated value; performing conjugate multiplication on the array output containing the target signal and the reconstructed array output of the reference signal to obtain the array output based on the frequency difference, and calculating the covariance matrix of the frequency difference output; calculating the weight value of the adaptive beam according to the covariance matrix of the frequency difference output to form the constant beam width adaptive beam. The application is simple and convenient, has small calculation amount, and can improve practicability.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of signal processing, and particularly relates to a constant beamwidth adaptive beamforming method and system based on frequency difference. BACKGROUND

[0002] Beamforming technology is a linear weighted combination processing of field information collected by a spatially distributed sensor array, so as to obtain a beam output in a certain direction in space. Therefore, the beamformer is also regarded as a spatial filter, and the beam response curve is called a beam pattern. The main lobe width of the beam pattern of the same array at different frequencies is different, and in order to make the wideband signal of the beam output distortionless, a constant beamwidth wideband beamformer needs to be designed, that is, the beamformer has the same main lobe response characteristics at different frequency points.

[0003] The constant beamwidth beamformer is widely used in the fields of sonar and speech processing. In the field of sonar, in order to enable the sonar operator to hear clear and distortionless target radiation noise, the constant beamwidth technology needs to be used to extract the sonar array receiving signal; in the field of speech processing, the constant beamwidth technology needs to be used to accurately extract the speech signal received by the microphone array. The commonly used constant beamwidth beamforming mainly uses the Chebyshev weighting method, which can realize the same main lobe width, but cannot adaptively suppress interference. The convex optimization algorithm can realize the adaptive beam optimization design of the constant beamwidth, but each frequency point needs to be iteratively optimized, and the calculation amount is large. SUMMARY

[0004] The technical problem to be solved by the application is to provide a constant beamwidth adaptive beamforming method and system based on frequency difference, which is simple and convenient, has small calculation amount, can improve practicability, and is used to solve the technical problem of beam response changing with frequency.

[0005] The application adopts the following technical scheme:

[0006] A constant beamwidth adaptive beamforming method based on frequency difference comprises the following steps:

[0007] S1, segmenting the time domain data of a target signal to perform FFT, converting the time domain data into frequency domain data, and calculating a data covariance matrix for each frequency point;

[0008] S2, estimating the direction of a target by using the data covariance matrix of each frequency point obtained in step S1 to obtain an estimated value of the direction of the target;

[0009] S3, generating a Gaussian random sequence with the same length as the array receiving signal as a reference signal, and reconstructing the array output of the reference signal according to the estimated value of the direction of the target obtained in step S2;

[0010] S4, multiply the array output containing the target signal with the conjugate of the array output of the reconstructed reference signal obtained in step S3 to obtain a frequency difference based array output, and calculate the covariance matrix of the frequency difference output;

[0011] S5, calculate the weight of the adaptive beam according to the covariance matrix of the frequency difference output obtained in step S4 to form a constant beam width adaptive beam.

[0012] Specifically, step S1 is specifically:

[0013] S101, arrange a horizontal uniform linear sensor array placed underwater, the number of array elements is , the array element spacing is , and the horizontal uniform linear sensor array is used to receive and record underwater acoustic signals, is an array output vector, and the number of sampling points in the total processing time is ;

[0014] S102, divide the sampling points obtained in step S101 into segments, and each segment data matrix is , and the fast Fourier transform of Q points is performed on each segment data matrix to obtain a frequency domain data matrix;

[0015] S103, calculate the data covariance matrix of each frequency point according to the frequency domain data matrix obtained in step S102.

[0016] Further, in step S103, the data covariance matrix is:

[0017]

[0018] wherein , is the number of fast Fourier transform points, is the frequency domain data matrix, and the superscript H is the conjugate transpose.

[0019] Specifically, in step S2, the target direction spectrum is calculated according to the data covariance matrix of each frequency point, the peak value of the target direction spectrum is searched to obtain an estimated value of the target direction , and the target direction spectrum is:

[0020]

[0021] wherein is the data covariance matrix, H is the conjugate transpose, , is the observation angle space of the array, , is the number of points of the fast Fourier transform, is the azimuth of the array manifold vector.

[0022] Specifically, step S3 is specifically:

[0023] a Gaussian random sequence with the same length as the received signal is generated , which is called a reference sequence, the length of the sequence is , and sampling points are equally divided into segments, and each segment of data matrix is . The fast Fourier transform of Q points is performed on each segment of data matrix to obtain the frequency domain data of the reference sequence , , which represents the frequency at the th frequency point; and the array output based on the reference sequence is calculated .

[0024] Further, the array output based on the reference sequence is:

[0025]

[0026] , wherein is the frequency domain data of the reference sequence, is the array manifold vector.

[0027] Specifically, in step S4, the covariance matrix of the frequency difference output is:

[0028]

[0029] , wherein is the number of data segments of the reference sequence, is the frequency difference array output, and H is the conjugate transpose.

[0030] Specifically, in step S5, the beam forming weight is determined according to the covariance matrix of the frequency difference output , the beam response diagram of the constant beam width beam former is given according to the weight , and the beam output of the constant beam width beam former is calculated .

[0031] ​Further, beam outputs of a constant beamwidth beamformer are:

[0032]

[0033] wherein, is a conjugate transpose of the beamforming weights, is a frequency-differenced array output, is a Hadamard product multiplier, is a reference sequence at the frequency.

[0034] In a second aspect, an embodiment of the present application provides a constant beam adaptive beamforming system based on frequency difference, comprising:

[0035] A conversion module, which performs segmented FFT on time domain data of a target signal, converts the time domain data into frequency domain data, and calculates a data covariance matrix for each frequency point;

[0036] An estimation module, which estimates the azimuth of the target by using the data covariance matrix of each frequency point obtained by the conversion module, and obtains an estimated value of the target azimuth;

[0037] A reconstruction module, which generates a Gaussian random sequence with the same length as the array receiving signal as a reference signal, and reconstructs the array output of the reference signal according to the target azimuth estimated value obtained by the estimation module;

[0038] A conjugate module, which performs conjugate multiplication on the array output containing the target signal and the reconstructed array output of the reference signal obtained by the reconstruction module, obtains a frequency-differenced array output, and calculates a covariance matrix of the frequency-differenced output;

[0039] An output module, which calculates the weights of the adaptive beam according to the covariance matrix of the frequency-differenced output obtained by the conjugate module, and forms a constant beamwidth adaptive beam.

[0040] Compared with the prior art, the present application has at least the following beneficial effects:

[0041] The application discloses a constant beam width adaptive beam forming method based on frequency difference, segments FFT of time domain data of a target signal, converts the time domain data into frequency domain data, calculates a data covariance matrix for each frequency point, and utilizes the data covariance matrix for subsequent target direction estimation; estimates the direction of the target by utilizing the data covariance matrix of each frequency point, obtains an estimated value of the target direction, and provides a beam pointing direction for subsequent beam forming weight design; generates a Gaussian random sequence with the same length as the array received signal as a reference signal, reconstructs the array output of the reference signal according to the estimated value of the target direction, and calculates the array output based on the frequency difference; performs conjugate multiplication on the array output containing the target signal and the reconstructed array output of the reference signal, obtains the array output based on the frequency difference, calculates a covariance matrix of the frequency difference output, and utilizes the covariance matrix of the frequency difference output for subsequent calculation of the beam forming weight; calculates the weight of the adaptive beam according to the covariance matrix of the frequency difference output, forms a constant beam width adaptive beam, and solves the constant beam width problem by mapping different frequency signals to the same frequency, without the complex iterative optimization process, and the calculation is simple and convenient.

[0042] Further, a horizontal uniform linear sensor array is arranged to be placed underwater, the number of array elements is , the array element spacing is , the underwater acoustic signals are received and recorded by the array, is an array output vector, the number of sampling points in the total processing time is , and the array output in the frequency domain is calculated; the sampling points are evenly divided into segments, each segment of data matrix is , the fast Fourier transform of Q points is performed on each segment of data matrix to obtain a frequency domain data matrix, and the data covariance matrix of each frequency point is calculated; the data covariance matrix of each frequency point is calculated according to the frequency domain data matrix , so as to estimate the target direction.

[0043] Further, the data covariance matrix of each frequency point is calculated through the frequency domain data matrix , and the target direction can be accurately estimated.

[0044] Further, the target direction spectrum is calculated according to the data covariance matrix of each frequency point , the peak value of the target direction spectrum is searched, and the estimated value of the target direction is obtained, so as to provide a beam pointing direction for subsequent beam forming weight design.

[0045] Further, a Gaussian random sequence with the same length as the received signal is generated , which is called reference sequence, the length of the sequence is , and the sampling points are equally divided into segments, and each segment data matrix is . Fast Fourier transform is performed on each segment data matrix Q , and the frequency domain data of the reference sequence is obtained , , where represents the frequency at the th frequency point; the array output based on the reference sequence is calculated , so as to subsequently calculate the array output based on the frequency difference.

[0046] Further, the array frequency domain data matrix is conjugate multiplied with the array output of the reference sequence , so as to subsequently calculate the beam forming weight value by using the covariance matrix of the frequency difference output.

[0047] Further, the covariance matrix of the frequency difference output is calculated , so as to subsequently calculate the beam forming weight value by using the covariance matrix of the frequency difference output.

[0048] Further, the beam forming weight value is determined according to the covariance matrix of the frequency difference output , and the beam response diagram of the constant beam width beam former is given according to the weight value , and the beam output of the constant beam width beam former is calculated , where is the array output of the frequency difference, is the reference sequence at the frequency, and is the Hadamard product multiplier, because the array frequency domain data at different frequencies is transformed to the same frequency point for the beam forming processing by the frequency difference processing, so that the constant beam width beam former is realized, and the complex calculation process of iterative optimization is not needed, and it is simple, convenient and easy to realize.

[0049] It can be understood that the beneficial effects of the above-mentioned second aspect can be referred to the related description in the above-mentioned first aspect, and will not be repeated here.

[0050] In summary, the present application can realize the frequency characteristics of the beam response, is simple and convenient to operate, has small calculation amount, can improve the practicability, and solves the problem that the beam response of the conventional beam former is not constant in frequency.

[0051] The technical solutions of the present application will be further described in detail below with the aid of the accompanying drawings and examples. BRIEF DESCRIPTION OF DRAWINGS

[0052] Figure 1 Flow chart of the present application;

[0053] Figure 2 Beam pattern obtained by the method of the present application;

[0054] Figure 3 Schematic diagram of the system of the present application. DETAILED DESCRIPTION

[0055] The technical solutions in the embodiments of the present application will be described clearly and completely below with the aid of the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative efforts belong to the scope of the present application.

[0056] In the description of the present application, it should be understood that the terms "comprise" and "include" indicate the existence of described features, integers, steps, operations, elements, and / or components, but do not exclude one or more other features, integers, steps, operations, elements, components, and / or sets thereof.

[0057] It should also be understood that the terms used in the specification of the present application are only for the purpose of describing specific embodiments and are not intended to limit the present application. As used in the specification and the appended claims of the present application, the singular forms "a", "an" and "the" are intended to include the plural forms unless the context clearly indicates otherwise.

[0058] It should be further understood that the term "and / or" used in the specification and the appended claims of the present application means any combination of one or more of the associated listed items and all possible combinations, and includes these combinations, for example, A and / or B can represent three cases of A alone, A and B together, and B alone. In addition, the character " / " in this paper generally represents that the front and rear associated objects are in an "or" relationship.

[0059] It should be understood that although the terms first, second, third, etc. may be used in the embodiments of the present application to describe the preset ranges, etc., these preset ranges should not be limited to these terms. These terms are only used to distinguish the preset ranges from each other. For example, the first preset range can also be referred to as the second preset range, and similarly, the second preset range can also be referred to as the first preset range without departing from the scope of the embodiments of the present application.

[0060] Depending on the context, the word "if' can be interpreted to mean "when" or "upon" or "in response to determining" or "in response to detecting." Similarly, the phrase "if it is determined" or "if [a stated condition or event] is detected" can be interpreted to mean "upon determining" or "in response to determining" or "upon detecting [the stated condition or event]" or "in response to detecting [the stated condition or event]."

[0061] Various structural diagrams according to the disclosed embodiments of the present application are shown in the accompanying drawings. These diagrams are not drawn to scale, in which certain details are shown in a somewhat exaggerated manner for purposes of clarity and understanding, and certain other details are omitted. The shapes and relative sizes of the various regions, layers, and elements illustrated in the drawings are exemplary only and can vary in actual implementation, depending on, for example, manufacturing techniques and / or technology restraints. The skilled person can design regions / elements with different shapes, sizes, and relative positions according to actual needs.

[0062] Referring to Figure 1 , the present application is a constant beamwidth adaptive beamforming method based on frequency difference, comprising the following steps:

[0063] S1, data preprocessing

[0064] The time-domain data of the underwater uniform linear array receiving the target signal is segmented by FFT, and the time-domain data is converted into frequency-domain data. The data covariance matrix is calculated for each frequency point;

[0065] S101, arranging a uniform linear sensor array horizontally placed underwater, the number of array elements is , the array element spacing is , and the array is used to receive and record underwater acoustic signals, is the array output vector, and the number of sampling points in the total processing time is ;

[0066] S102, dividing sampling points into segments, and each segment data matrix is . The fast Fourier transform of each segment data matrix is performed on Q points to obtain the frequency-domain data matrix , wherein represents the frequency of the th frequency point;

[0067] S103, calculating the data covariance matrix of each frequency point.

[0068]

[0069] wherein, H is the conjugate transpose.

[0070] S2, performing peak search on target direction spectrum , using each frequency point to calculate data covariance matrix to estimate the target direction, obtaining the estimated value of target direction ;

[0071] target direction spectrum is:

[0072]

[0073] wherein, , is the observation angle space of the array, i.e. 0~180°, is the estimated direction of the array manifold vector, i.e. , , is the known inter-element distance, is the underwater sound propagation speed.

[0074] S3, generating reference signal

[0075] generating a Gaussian random sequence with the same length as the array received signal as the reference signal, and reconstructing the array output of the reference signal according to the estimated target direction;

[0076] S301, generating a Gaussian random sequence with the same length as the received signal , which is called reference sequence, the length of the sequence is , and the sampling points are equally divided into segments, and each segment data matrix is . The fast Fourier transform of Q point is performed on each segment data matrix to obtain the frequency domain data , of the reference sequence, wherein represents the frequency at the th frequency point;

[0077] S302, calculating the array output based on the reference sequence;

[0078]

[0079] wherein, , , is the known inter-element distance, is the underwater sound propagation speed, is the target direction estimated in step S2.

[0080] S4, Frequency Differential Processing

[0081] The array output containing the target signal is conjugately multiplied with the array output reconstructed from the reference signal to obtain the frequency difference-based array output, and the covariance matrix of the frequency difference output is calculated. ;

[0082] Frequency differential array output for:

[0083]

[0084] in," "For Hadama multipliers, frequency" .

[0085] Covariance matrix of frequency differential output for:

[0086]

[0087] in, The number of data segments for the reference sequence. “ "For Hadama multipliers, frequency" The superscript H indicates the conjugate transpose.

[0088] S5. Calculate the weights of the adaptive beam based on the covariance matrix of the frequency difference output to form a constant beamwidth adaptive beam.

[0089] Based on the covariance matrix of the frequency difference output Determine beamforming weights According to the weight Give the beam response diagram of a constant beamwidth beamformer. The beam output of the constant beamwidth beamformer is calculated. .

[0090] Beamforming weights for:

[0091]

[0092] in, , , Given the known element spacing, This represents the speed at which sound waves travel underwater.

[0093] Beam response diagram of constant beamwidth beamformer for:

[0094]

[0095] wherein, .

[0096] Beam output of constant beamwidth beamformer is:

[0097]

[0098] wherein, is a reference sequence at the frequency.

[0099] In still another embodiment of the present application, referring to Figure 3 , there is provided a constant beamwidth adaptive beamforming system based on frequency difference, which can be used to implement the constant beamwidth adaptive beamforming method based on frequency difference. Specifically, the constant beamwidth adaptive beamforming system based on frequency difference comprises a conversion module, an estimation module, a reconstruction module, a conjugate module and an output module.

[0100] The conversion module performs segmented FFT on the time-domain data of the target signal, converts the time-domain data into frequency-domain data, and calculates a data covariance matrix for each frequency point.

[0101] The estimation module estimates the orientation of the target by using the data covariance matrix of each frequency point obtained by the conversion module, and obtains an estimated value of the target orientation.

[0102] The reconstruction module generates a Gaussian random sequence with the same length as the array receiving signal as a reference signal, and reconstructs the array output of the reference signal according to the estimated value of the target orientation obtained by the estimation module.

[0103] The conjugate module performs conjugate multiplication on the array output containing the target signal and the array output of the reconstructed reference signal obtained by the reconstruction module, obtains an array output based on frequency difference, and calculates a covariance matrix of the frequency difference output.

[0104] The output module calculates the weight value of the adaptive beam according to the covariance matrix of the frequency difference output obtained by the conjugate module, and forms a constant beamwidth adaptive beam.

[0105] In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the following will clearly and completely describe the technical solutions in the embodiments of the present application with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only some but not all of the embodiments of the present application. The components of the embodiments of the present application described and shown in the drawings herein can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present application provided in the drawings is not intended to limit the scope of the claimed present application, but only represents selected embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the scope of protection of the present application.

[0106] Embodiment

[0107] Three wideband signals are received by a 16-element hydrophone array, the signal bandwidths are all 500Hz-1000Hz, the signal directions are 50°, 70° and 130° respectively, and the hydrophone array element spacing is half of the wavelength at 1000Hz frequency. It is assumed that the signal incident in the direction of 70° is the signal of interest, the signals incident in the directions of 50° and 130° are interference, the signal-to-noise ratio is set to 0dB, and the interference-to-noise ratio is set to 20dB. The beam pattern obtained by using the method of the present application is shown in Figure 2 It can be seen that the method can obtain constant main lobe width in the frequency difference domain, and adaptively suppress interference in the frequency difference domain.

[0108] In summary, the constant beam adaptive beamforming method and system based on frequency difference can realize the frequency characteristics of the beam response, and is simple and convenient to operate, and has been implemented in engineering, and solves the problem that the beam response of the conventional beamformer is not constant in frequency.

[0109] Those skilled in the art should understand that the embodiments of the present application can be provided as a method, a system or a computer program product. Therefore, the present application can adopt a completely hardware embodiment, a completely software embodiment or an embodiment combining software and hardware aspects. Moreover, the present application can adopt the form of a computer program product implemented on one or more computer usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer usable program codes.

[0110] The computer program instructions can also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer-implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart or flows and / or block diagram block or blocks. Figure 1 one or more flow or flows and / or block diagram block or blocks. Figure 1 one or more flow or flows and / or block diagram block or blocks.

[0111] The computer program instructions can also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer-implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart or flows and / or block diagram block or blocks. Figure 1 one or more flow or flows and / or block diagram block or blocks. Figure 1 one or more flow or flows and / or block diagram block or blocks.

[0112] The computer program instructions can also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer-implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart or flows and / or block diagram block or blocks. Figure 1 one or more flow or flows and / or block diagram block or blocks. Figure 1 one or more flow or flows and / or block diagram block or blocks.

[0113] The above merely provides the technical idea of the present application, and cannot limit the protection scope of the present application. Any modification made according to the technical idea of the present application, on the basis of the technical solutions, falls within the protection scope of the present application.

Claims

1. A frequency-difference-based constant beamwidth adaptive beamforming method, characterized in that, The method comprises the following steps: S1, segmenting FFT of time domain data of a target signal, converting the time domain data into frequency domain data, and calculating data covariance matrix for each frequency point; S2, estimating the orientation of the target by using the data covariance matrix of each frequency point obtained in step S1, and obtaining an estimated value of the target orientation; S3, generating a Gaussian random sequence with the same length as the target signal as a reference signal, and reconstructing the reference signal according to the target orientation estimated value obtained in step S2; S4, performing conjugate multiplication of the target signal in step S1 and the reconstructed reference signal obtained in step S3 by using Hadamard product multiplier, obtaining frequency difference-based array output, and calculating the covariance matrix of the frequency difference output; S5, calculating the weight of adaptive beam according to the covariance matrix of frequency difference output obtained from step S4, and calculating the weight of adaptive beam according to the covariance matrix of frequency difference output determining beam forming weight , according to the weight giving the beam response diagram of constant beam width beam former , calculating the beam output of constant beam width beam former .

2. The frequency-difference-based constant beamwidth adaptive beamforming method according to claim 1, wherein, Step S1 is specifically: S101, a horizontal uniform linear sensor array is arranged to be placed underwater, the number of array elements is , the array element spacing is , the horizontal uniform linear sensor array is used to receive and record underwater acoustic signals, is an array output vector, and the number of sampling points in the total processing time is ; S102, the result obtained in step S101 The average of the sampling points is divided into Each segment is a data matrix. Perform the following steps on each data matrix segment: Q The point-based fast Fourier transform yields the frequency domain data matrix; S103. Calculate the data covariance matrix of each frequency point according to the frequency domain data matrix obtained in step S102 .

3. The frequency-difference-based constant beamwidth adaptive beamforming method according to claim 2, wherein, In step S103, the data covariance matrix is: wherein , is the number of points of the fast Fourier transform, is the matrix of frequency domain data, the superscript H is the conjugate transpose.

4. The frequency-difference-based constant beamwidth adaptive beamforming method of claim 1, wherein, In step S2, the target direction spectrum is calculated according to the data covariance matrix of each frequency point The target direction spectrum is calculated according to the data covariance matrix of each frequency point The peak value is searched to obtain the estimated value of the target direction The target direction spectrum is calculated according to the data covariance matrix of each frequency point ​ wherein is the data covariance matrix, the superscript H is the conjugate transpose, , is the observation angle space of the array, , is the number of fast Fourier transform points, is the array manifold vector at azimuth .

5. The frequency-difference-based constant beamwidth adaptive beamforming method of claim 1, wherein, Step S3 is specifically: Generating a gaussian random sequence with the same length as the target signal , as a reference signal, the signal length is , also divide sampling points equally into segments, and each segment data matrix is ; The Fourier transform of the points is performed for each data matrix Q to obtain the frequency domain data of the reference signal , denotes the frequency at the th frequency point; the array output based on the reference signal is calculated .

6. The frequency-difference-based constant beamwidth adaptive beamforming method according to claim 5, wherein, Array output based on reference signals For: wherein is the frequency domain data of the reference sequence, is the array manifold vector.

7. The frequency-difference-based constant beamwidth adaptive beamforming method of claim 1, wherein, In step S4, the frequency-differenced output covariance matrix is: wherein is the number of data segments of the reference sequence, is the frequency-differenced array output, with superscript H denoting the conjugate transpose.

8. The frequency-difference-based constant beamwidth adaptive beamforming method of claim 1, wherein, Beam output of a constant beamwidth beamformer Is: wherein, is a conjugate transpose of a beamforming weight, is a frequency-differenced array output, is a Hadamard product multiplier, is a reference sequence at a frequency.

9. A frequency-difference-based constant beamwidth adaptive beamforming system, characterized by, comprises: a conversion module for segmenting FFT of time domain data of a target signal, converting the time domain data into frequency domain data, and calculating data covariance matrix for each frequency point; an estimation module for estimating the orientation of the target by using the data covariance matrix of each frequency point obtained by the conversion module, and obtaining an estimated value of the target orientation; a reconstruction module for generating a Gaussian random sequence with the same length as the target signal as a reference signal, and reconstructing the reference signal according to the target orientation estimated value obtained by the estimation module; a conjugate module for performing conjugate multiplication of the target signal and the reconstructed reference signal obtained by the reconstruction module by using Hadamard product multiplier, obtaining frequency difference-based array output, and calculating the covariance matrix of the frequency difference output; The output module calculates the weight of the adaptive beam according to the covariance matrix of the frequency difference output obtained by the conjugate module, and calculates the beam output of the constant beam width beamformer according to the covariance matrix of the frequency difference output determining beamforming weights , according to the weight give the beam response diagram of the constant beam width beamformer , the beam output of the constant beam width beamformer is calculated.

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