Adaptive beamforming method and system applied to radio astronomy aperture array

Abstract

The application provides an adaptive beam forming method and system applied to a radio astronomy aperture array, and relates to the field of digital signal processing.The application comprises presetting an initial general combined beam weight vector and an iteration step value;receiving real-time cosmic radio radiation signals through the radio astronomy aperture array;processing the cosmic radio radiation signals through a subarray digital processor to obtain a general combined beam of the complete array;processing the general combined beam through a threshold value determination method to determine an interference frequency subband;updating the adaptive beam weight vector of the interference frequency subband through the subarray digital processor and generating an adaptive combined beam;and finally outputting the general combined beam and the adaptive combined beam.The application iteratively generates adaptive beam weights in each subarray, the calculation process is simple, the data interaction amount is greatly reduced, the application is suitable for FPGA-based hardware implementation, and the application has the advantages of high real-time performance and strong adaptability.

Description

Technical Field

[0001] This invention relates to the field of digital signal processing technology, and more specifically to an adaptive beamforming method and system for radio astronomy aperture arrays. Background Technology

[0002] To meet the demands of radio astronomy for higher resolution and sensitivity, next-generation radio telescopes largely employ aperture arrays. These arrays use a large number of independent antenna elements arranged in a phased array to create a large synthetic aperture, reducing the difficulty of achieving ultra-large apertures. Simultaneously, by forming multiple beams simultaneously, the observation range and survey speed of aperture array radio telescopes are greatly enhanced. Especially in the low-frequency band, almost all large radio telescopes utilize aperture arrays, such as the Square Kilometre Array (SKA), the Low Frequency Array (LOFAR), the Long Wavelength Array (LWA), the Murchison Wide-Field Array (MWA), and the 21 CentiMeter Array (21CMA).

[0003] With the rapid development of human industry and information activities, the number of portable point-to-point communication devices and communication satellites has increased dramatically, making interference to radio astronomy observations increasingly difficult to avoid. Furthermore, the wide field of view of the antenna elements that form aperture arrays makes them more sensitive to interference signals from all directions. Although radio astronomy aperture arrays are typically located in electromagnetically quiet zones, they are still susceptible to radio frequency interference signals, significantly impacting observation quality and efficiency. Traditional radio telescopes primarily employ a time-domain "mark-and-drop" interference cancellation method, which is simple to implement but results in irrecoverable lost data. Aperture array radio telescopes, due to their spatial filtering characteristics, possess the ability to separate interference signals from the astronomical signals of interest, enabling normal observations while suppressing interference.

[0004] Existing large aperture arrays, such as the SKA low-frequency telescope, use conventional beamforming methods, which can form static null points in known interference directions, but cannot suppress interference signals from unknown incoming wave directions. Summary of the Invention

[0005] (a) Technical problems to be solved To address the shortcomings of existing technologies, this invention provides an adaptive beamforming method and system for radio astronomy aperture arrays, solving the problem that traditional methods cannot suppress interference signals from unknown directional sources.

[0006] (II) Technical Solution To achieve the above objectives, the present invention provides the following technical solution: In a first aspect, the present invention provides an adaptive beamforming method for use in radio astronomy aperture arrays, the method comprising: Preset the initial conventional synthetic beam weight vector and iteration step size; Real-time cosmic radio emission signals are acquired using radio aperture arrays. Based on the conventional synthetic beam weight vector, the cosmic radio emission signal is processed by the subarray digital processor to obtain the conventional synthetic beam of the complete array; The conventional synthesized beam is processed by a threshold determination method to determine the conventional frequency sub-band and the interference frequency sub-band affected by interference. Based on the iteration step size value, the adaptive beam weight vector of the interference frequency sub-band is updated by the sub-array digital processor. At the same time, an adaptive beam is generated and accumulated based on the adaptive beam weight vector to obtain the adaptive synthetic beam of the complete array. The conventional frequency subband outputs a conventional synthesized beam, while the interference frequency subband outputs a user-selected conventional synthesized beam or an adaptive synthesized beam.

[0007] Preferably, the step of processing the cosmic radio emission signal through a subarray digital processor to obtain a conventional synthetic beam of the complete array includes: The cosmic radio emission signal is channelized in the frequency domain by a subarray digital processor to obtain a subarray frequency domain snapshot. Based on the conventional synthetic beam weight vector, multiple subarray conventional synthetic beams are calculated and accumulated to obtain the conventional synthetic beam of the complete array.

[0008] Preferably, the expression for the adaptive synthesized beam is: in, represents the adaptive beam of the i-th subarray; M represents the number of subarrays; This represents the adaptive beam weight vector of the i-th subarray, which is updated in real time as the frequency domain snapshot data of the subarray is updated; H represents the frequency domain snapshot of the i-th subarray; H is the transpose symbol.

[0009] Preferably, the method further includes: The host computer reads the sub-band number of the interference frequency sub-band and extracts the consecutive sub-bands with consecutive numbers; The adaptive beam weight vector of the continuous sub-band is read by the host computer, and the spatial spectrum of the interference frequency sub-band is calculated based on the adaptive beam weight vector. The spatial spectra of the interference frequency sub-bands are summed to obtain the summed spatial spectrum; Search for the minimum value below a preset threshold in the accumulated spatial spectrum to obtain the direction of the interference source.

[0010] Preferably, the number of sub-bands in the continuous sub-band is not less than two.

[0011] Preferably, the conventional synthesized beam of the complete array is obtained by cascading and accumulating the conventional synthesized beams of the multiple subarrays.

[0012] Secondly, the present invention also provides an adaptive beamforming system for radio astronomy aperture arrays, characterized in that the system comprises: The numerical preset module presets the initial conventional synthetic beam weight vector and iteration step size. The signal acquisition module acquires real-time cosmic radio emission signals through a radio astronomy aperture array; The first processing module processes the cosmic radio emission signal through a subarray digital processor based on the conventional synthetic beam weight vector to obtain the conventional synthetic beam of the complete array. The interference determination module processes the conventional synthesized beam using a threshold determination method to determine the conventional frequency sub-band and the interference frequency sub-band affected by interference. The second processing module updates the adaptive beam weight vector of the interference frequency sub-band through the sub-array digital processor based on the iteration step size value, and generates and accumulates an adaptive beam based on the adaptive beam weight vector to obtain the adaptive synthetic beam of the complete array. The beam output module outputs a conventional synthesized beam in the conventional frequency sub-band and a user-selected conventional synthesized beam or adaptive synthesized beam in the interference frequency sub-band.

[0013] Preferably, the system further includes an interference source directional module, the interference source directional module comprising: The host computer reads the sub-band number of the interference frequency sub-band and extracts the consecutive sub-bands with consecutive numbers; The adaptive beam weight vector of the continuous sub-band is read by the host computer, and the spatial spectrum of the interference frequency sub-band is calculated based on the adaptive beam weight vector. The spatial spectra of the interference frequency sub-bands are summed to obtain the summed spatial spectrum; Search for the minimum value below a preset threshold in the accumulated spatial spectrum to obtain the direction of the interference source.

[0014] Thirdly, the present invention also provides a computer-readable storage medium storing a computer program for an adaptive beamforming method applied to a radio astronomical aperture array, wherein the computer program causes a computer to execute the adaptive beamforming method for a radio astronomical aperture array as described above.

[0015] Fourthly, the present invention also provides an electronic device, comprising: One or more processors, a memory, and one or more programs, wherein the one or more programs are stored in the memory and configured to be executed by the one or more processors, the programs including methods for performing adaptive beamforming methods applied to radio astronomy aperture arrays as described above.

[0016] (III) Beneficial Effects This invention provides an adaptive beamforming method and system for radio astronomy aperture arrays. Compared with existing technologies, it has the following advantages: This invention first sets the initial weight vector as the guiding vector for the array beam target, and sets an appropriate iteration step size. Then, each subarray calculates and updates its weight vector and subarray beam based on real-time frequency domain channelized data, the initial weight vector, and the complete array beam data. The subarray beams are then combined into a complete array composite beam and output. The updated weight vector and complete beam data are used for a new round of iteration. This calculation process is repeated to achieve iterative updates of the beam weight vector and real-time updates of the complete array beam. This invention overcomes the limitations of existing technologies, such as large data exchange volume and high computational complexity, supports distributed, real-time, and scalable hardware implementation, and is suitable for large-scale radio astronomy aperture arrays. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 This is a flowchart illustrating an adaptive beamforming method for radio astronomy aperture arrays provided in an embodiment of the present invention. Figure 2 This is a schematic diagram of a module for an adaptive beamforming system applied to radio astronomy aperture arrays, provided in an embodiment of the present invention. Figure 3This is a schematic diagram of an adaptive beamformer applied to radio astronomy aperture arrays, provided by an embodiment of the present invention. Figure 4 An example of a beam pattern obtained by an adaptive beamforming method for radio astronomy aperture arrays provided in an embodiment of the present invention when there is two sidelobe interference; Figure 5 An example of the spatial spectrum obtained by the broadband interference source direction finding method provided in this embodiment of the invention when there are two sidelobe interferences. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention are described clearly and completely. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0020] This application provides an adaptive beamforming method and system for radio astronomy aperture arrays, which solves the problems of computational complexity and inability to respond in a timely manner in traditional methods. It realizes distributed parallel processing, reduces computational complexity, and greatly improves real-time response capability.

[0021] The technical solution in this application is to solve the above-mentioned technical problems, and the general idea is as follows: Adaptive beamforming methods are widely used in radar and communication systems, generating adaptive array weights based on received array data samples to automatically nullify the direction of incoming interference signals. However, their application in radio astronomy faces two major technical bottlenecks: First, radio astronomical aperture arrays often employ a hierarchical beamforming architecture, where radio frequency signals from the antenna front end are first beamformed into subarrays before being fully synthesized. These operations are implemented by different hardware components, making it difficult to obtain complete samples simultaneously containing all antennas. Second, because the hardware resources of digital processing systems are primarily used for the digital channelization of broadband received signals, only a small portion of resources are available for digital beamforming, making it difficult to support the implementation of highly complex beamforming algorithms. Moreover, as the scale of the aperture array increases, the hardware used for real-time processing becomes more dispersed, making it extremely difficult to achieve complete array sample data exchange. Therefore, to achieve real-time adaptive beamforming on radio astronomical aperture arrays, it is necessary to find a method that can be processed in a distributed parallel manner with low computational complexity.

[0022] The purpose of this invention is to provide a real-time adaptive beamforming method for radio astronomical aperture arrays, overcoming the shortcomings of existing technologies that require complete data samples for all channels and have high computational complexity. This method enables real-time distributed adaptive beamforming on radio astronomical aperture arrays and simultaneously achieves directionality of broadband interference sources.

[0023] To achieve the above objectives, this invention provides an adaptive beamforming method applicable to radio astronomy aperture arrays based on FPGA real-time processors. This method generates subarray frequency domain snapshot data in real time and performs real-time digital beamforming. For interfered frequency sub-bands, each subarray simultaneously maintains two sets of weighting coefficients: conventional synthetic weights and adaptive synthetic weights, used to generate conventional synthetic beam data and adaptive synthetic beam data for the complete array. The adaptive synthetic weight vector is iteratively updated based on this real-time data. For broadband signals covering multiple frequency domain sub-bands, the host computer reads the adaptive beam weight vectors of multiple subarrays at the same time, calculates the superimposed spatial spectrum of all sub-bands, and performs angle search to achieve the directionality of the interference source. To better understand the above technical solution, the following will provide a detailed description of the technical solution in conjunction with the accompanying drawings and specific implementation methods.

[0024] like Figure 1 As shown, this embodiment of the invention provides an adaptive beamforming method for radio astronomy aperture arrays, comprising: Step S110: Preset the initial conventional synthetic beam weight vector and iteration step size value.

[0025] Step S120: Real-time cosmic radio emission signals are acquired through a radio astronomy aperture array.

[0026] Step S130: Based on the conventional synthetic beam weight vector, the cosmic radio emission signal is processed by the subarray digital processor to obtain the conventional synthetic beam of the complete array.

[0027] Step S140: Process the conventional synthesized beam using the threshold determination method to determine the conventional frequency sub-band and the interference frequency sub-band affected by interference.

[0028] In step S150, the adaptive beam weight vector of the interference frequency sub-band is updated by the sub-array digital processor based on the iteration step size value. At the same time, an adaptive beam is generated and accumulated based on the adaptive beam weight vector to obtain the adaptive synthetic beam of the complete array.

[0029] Step S160: Output a conventional synthesized beam in the conventional frequency sub-band, and output a user-selected conventional synthesized beam or an adaptive synthesized beam in the interference frequency sub-band.

[0030] The adaptive beamforming method provided by this invention first sets the initial weight vector as the guiding vector pointing to the array beam target, and sets an appropriate iteration step size. Then, each subarray calculates and updates its weight vector and subarray beam based on real-time frequency domain channelized data, the initial weight vector, and the complete array beam data. The subarray beams are then combined into a complete array composite beam and output. The updated weight vector and complete beam data are used for a new round of iteration. This calculation process is repeated to achieve iterative updating of the beam weight vector and real-time updating of the complete array beam. This invention overcomes the limitations of existing technologies, such as large data exchange volume and high computational complexity, supports distributed, real-time, and scalable hardware implementation, and is suitable for large-scale radio astronomy aperture arrays.

[0031] Step S110: Preset the initial conventional synthetic beam weight vector and iteration step size value.

[0032] Specifically, setting the initial weight vector ,in Let be the guiding vector of the array pointing towards the target. The initial weight vector can be represented by subarray partitioning as follows: ,in It is Vector, and , This represents the number of antenna elements in the subarray. N denoted as the total number of antennas, M as the number of subarrays, and T as the transpose.

[0033] Set the iteration step size value Among them, the iteration step size value It can be calculated based on the actual collected samples to balance convergence speed and final performance.

[0034] Step S120: Real-time cosmic radio emission signals are acquired through a radio astronomy aperture array.

[0035] Specifically, cosmic radio emission signals are time-domain signals.

[0036] Step S130: Based on the conventional synthetic beam weight vector, the cosmic radio emission signal is processed by the subarray digital processor to obtain the conventional synthetic beam of the complete array. The specific implementation steps of this step include: Step S131: The cosmic radio emission signal is channelized in the frequency domain by the subarray digital processor to obtain the subarray frequency domain snapshot.

[0037] Step S132: Calculate and sum multiple subarray conventional synthetic beams based on the conventional synthetic beam weight vector to obtain the conventional synthetic beam of the complete array.

[0038] Specifically, each subarray digital processor performs frequency domain channelization on the time-domain signal to obtain the subarray frequency domain snapshot. , where K is the snapshot count.

[0039] Specifically, for each new subarray frequency domain snapshot X(K) obtained, each subarray independently calculates the subarray conventional composite beam. The M subarray beams are summed to obtain the conventional synthetic beam of the complete array. .

[0040] Preferably, this embodiment uses a cascaded accumulation method to accumulate the conventional synthesized beams of each subarray to obtain the conventional synthesized beam of the complete array. Cascaded accumulation can achieve better module versatility and scalability.

[0041] Step S140: Process the conventional synthesized beam using the threshold determination method to determine the conventional frequency sub-band and the interference frequency sub-band affected by interference.

[0042] Specifically, based on expert experience, a threshold for conventional synthetic beam data is pre-set. When the conventional synthetic beam data exceeds the threshold, the corresponding sub-band is interfered with and is identified as the interference frequency sub-band. Conversely, those that do not exceed the threshold are conventional beams and correspond to the corresponding conventional frequency sub-bands.

[0043] Step S150: Based on the iteration step size value, the adaptive beam weight vector of the interference frequency sub-band is updated by the sub-array digital processor, and an adaptive beam is generated and accumulated based on the adaptive beam weight vector to obtain the adaptive synthetic beam of the complete array.

[0044] Specifically, adaptive beamforming is performed only on the interference frequency sub-band, and the expression for the adaptive synthesized beam is: in, represents the adaptive beam of the i-th subarray; M represents the number of subarrays; This represents the adaptive beam weight vector of the i-th subarray, which is updated in real time as the frequency domain snapshot data of the subarray is updated; H represents the frequency domain snapshot of the i-th subarray; H is the transpose symbol.

[0045] The adaptive beam weight vector calculated for the i-th subarray across the L interference frequency sub-bands is: in, This represents the adaptive beam weight vector before the i-th subarray is updated (the initial value is an appropriate amount of the normal beam weight). This represents the updated adaptive beam weight vector for the i-th subarray; This represents the frequency domain snapshot of the i-th subarray; Indicates the iteration step size; Y cThis indicates the conventional synthetic beam before the update; V si This represents the initial weight vector of the i-th subarray; Y p This indicates the adaptive synthesized beam before the update, and * indicates complex conjugation.

[0046] Step S160: Output a conventional synthesized beam in the conventional frequency sub-band, and output a user-selected conventional synthesized beam or an adaptive synthesized beam in the interference frequency sub-band.

[0047] Specifically, the uninterrupted regular frequency sub-band outputs a regular synthesized beam, while the interfering frequency sub-band can be selected by the user to output a regular synthesized beam or an adaptive synthesized beam.

[0048] In this embodiment, based on adaptive beamforming, this application also provides broadband interference source direction finding, specifically including: Step S210: Read the sub-band number of the interference frequency sub-band through the host computer and extract the continuous sub-band with consecutive numbers.

[0049] Step S220: The adaptive beam weight vector of the continuous sub-band is read by the host computer, and the spatial spectrum of the interference frequency sub-band is calculated based on the adaptive beam weight vector.

[0050] Step S230: Accumulate the spatial spectrum of the interference frequency sub-bands to obtain the accumulated spatial spectrum.

[0051] Step S240: Search for the minimum value in the accumulated spatial spectrum that is below a preset threshold to obtain the direction of the interference source.

[0052] Specifically, the host computer reads the numbers of the interfered sub-bands and selects several sub-bands with consecutive numbers. Simultaneously read the corresponding sub-bands of all subarrays. Adaptive weights ; Calculate the spatial spectrum of each sub-band The formula for calculating the spatial spectrum is as follows: Indicates that subarray 1 is in θ The steering vector of the direction; T is the transpose sign. L consecutive frequency sub-bands. Spatial spectrum accumulation on, The search accumulates local minima on the spatial spectrum, where local minima below a certain threshold correspond to the direction of the interference source.

[0053] In this embodiment, the number of consecutive sub-bands is no less than two. The number of consecutive frequency sub-bands affected by broadband interference sources is related to the width of the sub-bands. To achieve direction finding of interference sources, this method requires at least two consecutive sub-bands. Increasing the number of sub-bands can improve direction finding estimation performance.

[0054] The adaptive beamforming and broadband interference source direction finding method provided in this embodiment first sets the initial weight vector as the guiding vector pointing to the array beam target, and sets an appropriate iteration step size. Then, each subarray calculates and updates its weight vector and subarray beam based on real-time frequency domain channelized data, the initial weight vector, and the complete array beam data. The subarray beams are then combined into a complete array composite beam and output. The updated weight vector and complete beam data are used for a new round of iteration. This calculation process is repeated to achieve iterative updating of the beam weight vector and real-time updating of the complete array beam. For multiple consecutive frequency subbands affected by interference, the array spatial spectrum can be obtained through simple multiplication and addition operations based on the adaptive beamforming weight vector, thus achieving direction finding of broadband interference sources. This invention overcomes the limitations of existing technologies, such as large data exchange volume and high computational complexity, supports distributed, real-time, and scalable hardware implementation, and is suitable for large-scale radio astronomy aperture arrays.

[0055] Considering the versatility and scalability of beamformers, each subarray beamformer is designed to have the exact same structure and function, such as Figure 3 As shown. Each subarray receives partial beam input from the previous level and outputs a partially synthesized beam, which is the sum of the partial synthesized beam of its own subarray. When the subarray is the first subarray, its partial beam input is 0. When the subarray is the last subarray, its output is the complete synthesized beam. This data is distributed to the beamformers of each subarray through a switch.

[0056] The number of antennas processed by a single subarray beamformer is determined by a comprehensive consideration of the system's instantaneous operating bandwidth, quantization bit depth, digital channelization parameters, and the processing capability of the selected subarray processor. Preferably, for a typical low-frequency radio telescope with an instantaneous operating bandwidth not exceeding 300MHz, a quantization bit depth not exceeding 16 bits, 512 digital channelization channels, and using a mainstream commercial FPGA as the subarray digital processor, a single subarray can process 8 or 16 antennas.

[0057] The method provided in this embodiment, as the number of iterations increases, generates an antenna pattern corresponding to the adaptive beamforming weights that approximates the statistically optimal adaptive beamforming pattern. Figure 4 As shown. When the target incident direction is 0°, interference exists in two directions: 13.5° and 41°. The interference-to-noise ratio (INR) is 20dB. The antenna array is a 42m diameter, 256-element randomly arranged circular array with an operating frequency range of 50-350MHz. The iteration step size is set to 5×10.-6 At that time, the antenna pattern corresponding to different number of snapshots is as follows: Figure 4 As shown in the figure, the starting point of the adaptive beamforming pattern iteration is the conventional beamforming pattern. This indicates that when there is no external interference, it has the same performance as a conventional beamformer. The main lobe direction of the adaptive beamforming pattern remains unchanged, and the -3dB beamwidth is almost identical to that of the conventional beamforming pattern, exhibiting good main lobe characteristics. As the number of iterations increases, the adaptive beamformer forms increasingly deeper zeros in the interference direction. In the embodiment, when the number of snapshots (i.e., the number of iterations) exceeds 2000, zeros deeper than -50dB have been formed in both interference directions. Taking a working clock frequency of 200MHz as an example, this corresponds to a convergence time of 10 microseconds, which fully meets the real-time requirements of radio astronomy observations.

[0058] When the target incident direction is 0°, broadband interference exists in two directions, 13.5° and 41°, with an interference-to-noise ratio (INR) of 20dB. The interference source is a broadband broadcast television signal with a frequency range of 84MHz – 92MHz. The array is a 16-element uniform linear array with an element spacing of 2.5 meters. When the frequency subband width of the processing system is designed to be 0.78125MHz, the obtained cumulative spatial spectrum is as follows: Figure 5 As shown in the figure, a series of minimum values ​​appear. When the threshold is set to -40dB, two minimum values ​​can be selected, which correspond to the direction of the interference source. This method is based on the weights of the adaptive beamformer, so the obtained direction of the interference source is updated in real time.

[0059] like Figure 2 As shown, the present invention also provides an adaptive beamforming system for radio astronomy aperture arrays, comprising: The numerical preset module presets the initial conventional synthetic beam weight vector and iteration step size. The signal acquisition module acquires real-time cosmic radio emission signals through a radio astronomy aperture array; The first processing module processes cosmic radio emission signals through a subarray digital processor based on conventional synthetic beam weight vectors to obtain the conventional synthetic beam of the complete array. The interference determination module processes the conventional synthesized beam using a threshold determination method to identify the conventional frequency sub-band and the interference frequency sub-band affected by interference. The second processing module updates the adaptive beam weight vector of the interference frequency sub-band through the sub-array digital processor based on the iteration step size value, and generates and accumulates the adaptive beam based on the adaptive beam weight vector to obtain the adaptive synthetic beam of the complete array. The beam output module outputs a conventional synthesized beam in the normal frequency subband and a user-selected conventional synthesized beam or adaptive synthesized beam in the interference frequency subband.

[0060] In this embodiment, the system further includes an interference source directional module, which includes: The host computer reads the sub-band number of the interference frequency sub-band and extracts the consecutive sub-bands with consecutive numbers.

[0061] The adaptive weights of continuous sub-bands are read by the host computer, and the spatial spectrum of the interference frequency sub-bands is calculated based on the adaptive weights.

[0062] The spatial spectrum of the interference frequency sub-bands is accumulated to obtain the accumulated spatial spectrum.

[0063] The direction of the interference source is obtained by searching for and accumulating the minimum value below the preset threshold in the spatial spectrum.

[0064] It is understood that the adaptive beamforming system for radio astronomical aperture arrays provided in this embodiment of the invention corresponds to the adaptive beamforming method for radio astronomical aperture arrays described above. The explanations, examples, and beneficial effects of the relevant content can be referred to the corresponding content in the adaptive beamforming method for radio astronomical aperture arrays, and will not be repeated here.

[0065] This invention also provides a computer-readable storage medium storing a computer program for an adaptive beamforming method applied to a radio astronomical aperture array, wherein the computer program causes a computer to execute the adaptive beamforming method for a radio astronomical aperture array as described above.

[0066] This application also provides an electronic device, including: one or more processors; a memory; and one or more programs, wherein the one or more programs are stored in the memory and configured to be executed by the one or more processors, the programs including methods for performing adaptive beamforming methods applied to radio astronomy aperture arrays as described above.

[0067] In summary, compared with existing technologies, it has the following beneficial effects: 1. The embodiments of the present invention solve the contradiction between the large amount of sample data interaction, high computational complexity and dispersed hardware resources faced by large-scale array adaptive beamforming and broadband interference source direction finding methods, and provide methodological support for large-scale radio astronomy aperture arrays to realize real-time adaptive beamforming and interference source direction finding.

[0068] 2. The embodiments of the present invention can sense broadband interference affecting multiple consecutive frequency subbands. After reading the adaptive weights, the spatial spectrum containing the spatial feature information of the interference source can be obtained through simple multiplication and addition operations, thereby realizing the orientation of the broadband interference source. It does not require the complex calculations such as sample covariance matrix calculation and matrix decomposition required by traditional array spatial spectrum estimation methods, and has the advantages of low computational complexity and distributed parallel computing.

[0069] 3. In the embodiments of the present invention, the adaptive beam weights are generated iteratively in each subarray. The calculation process only involves the real-time data of the subarray frequency domain snapshot, the weight vector of the subarray, and the conventional and adaptive synthetic beam data of the complete array, which greatly reduces the amount of data interaction and has low computational complexity. It is suitable for implementation based on FPGA and has high real-time performance.

[0070] 4. In the subarray weight coefficient update process of this invention, the conventional synthesis and adaptive synthesis beams of the subarray and the updated weight vector can be calculated simultaneously, and no data interaction between subarrays is required in this process, which meets the requirements of distributed parallel computing, greatly reduces the calculation time, enables real-time updating of weight coefficients, and improves the adaptability to moving interference targets.

[0071] 5. In the processing of this embodiment of the invention, the configuration parameters can be adjusted to select between outputting conventional synthetic beam data or adaptive synthetic beam data, which has good adaptability.

[0072] 6. The method proposed in this embodiment is not limited to regular arrays and can be used for arbitrary array layouts, such as the sparse random array used in the SKA low-frequency telescope. For sidelobe interference, the radiation pattern obtained using this method can generate nulls in the interference direction and has a main lobe very close to that of conventional beamforming methods, satisfying the requirements of radio astronomy for maintaining the main lobe width and gain.

[0073] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus 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 apparatus. 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 apparatus that includes said element.

[0074] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. An adaptive beamforming method for radio astronomy aperture arrays, characterized in that, The method includes: Preset the initial conventional synthetic beam weight vector and iteration step size; Real-time cosmic radio emission signals are acquired using radio aperture arrays. Based on the conventional synthetic beam weight vector, the cosmic radio emission signal is processed by the subarray digital processor to obtain the conventional synthetic beam of the complete array; The conventional synthesized beam is processed by a threshold determination method to determine the conventional frequency sub-band and the interference frequency sub-band affected by interference. Based on the iteration step size value, the adaptive beam weight vector of the interference frequency sub-band is updated by the sub-array digital processor. At the same time, an adaptive beam is generated and accumulated based on the adaptive beam weight vector to obtain the adaptive synthetic beam of the complete array. The conventional frequency sub-band outputs a conventional synthesized beam, while the interference frequency sub-band outputs a user-selected conventional synthesized beam or an adaptive synthesized beam. The method further includes: The host computer reads the sub-band number of the interference frequency sub-band and extracts the consecutive sub-bands with consecutive numbers; The adaptive beam weight vector of the continuous sub-band is read by the host computer, and the spatial spectrum of the interference frequency sub-band is calculated based on the adaptive beam weight vector. The spatial spectra of the interference frequency sub-bands are summed to obtain the summed spatial spectrum; Search for the minimum value below a preset threshold in the accumulated spatial spectrum to obtain the direction of the interference source.

2. The adaptive beamforming method according to claim 1, characterized in that, The process of processing the cosmic radio emission signal through a subarray digital processor to obtain the conventional synthetic beam of the complete array includes: The cosmic radio emission signal is channelized in the frequency domain by a subarray digital processor to obtain a subarray frequency domain snapshot. Based on the conventional synthetic beam weight vector and the subarray frequency domain snapshot, multiple subarray conventional synthetic beams are calculated and accumulated to obtain the conventional synthetic beam of the complete array.

3. The adaptive beamforming method according to claim 2, characterized in that, The expression for the adaptive synthetic beam is: in, Indicates the first i Adaptive beamforming of subarrays; M represents the number of subarrays; This represents the adaptive beam weight vector of the i-th subarray, which is updated in real time as the frequency domain snapshot data of the subarray is updated; H represents the frequency domain snapshot of the i-th subarray; H is the transpose symbol.

4. The adaptive beamforming method for radio astronomy aperture arrays according to claim 1, characterized in that, The number of sub-bands in the continuous sub-band is not less than two.

5. The adaptive beamforming method for radio astronomy aperture arrays according to claim 1, characterized in that, The conventional composite beam of the complete array is obtained by cascading and accumulating multiple subarray conventional composite beams.

6. An adaptive beamforming system for radio astronomy aperture arrays, characterized in that, The system includes: The numerical preset module presets the initial conventional synthetic beam weight vector and iteration step size. The signal acquisition module acquires real-time cosmic radio emission signals through a radio astronomy aperture array; The first processing module processes the cosmic radio emission signal through a subarray digital processor based on the conventional synthetic beam weight vector to obtain the conventional synthetic beam of the complete array. The interference determination module processes the conventional synthesized beam using a threshold determination method to determine the conventional frequency sub-band and the interference frequency sub-band affected by interference. The second processing module updates the adaptive beam weight vector of the interference frequency sub-band through the sub-array digital processor based on the iteration step size value, and generates and accumulates an adaptive beam based on the adaptive beam weight vector to obtain the adaptive synthetic beam of the complete array. The beam output module outputs a conventional synthesized beam in the conventional frequency sub-band and a user-selected conventional synthesized beam or adaptive synthesized beam in the interference frequency sub-band. The interference source direction-finding module reads the sub-band number of the interference frequency sub-band from the host computer and extracts continuous sub-bands with consecutive numbers; it reads the adaptive beam weight vector of the continuous sub-band from the host computer and calculates the spatial spectrum of the interference frequency sub-band based on the adaptive beam weight vector; it accumulates the spatial spectra of the interference frequency sub-band to obtain the accumulated spatial spectrum; and it searches for the minimum value below a preset threshold in the accumulated spatial spectrum to obtain the direction of the interference source.

7. A computer-readable storage medium, characterized in that, It stores a computer program for an adaptive beamforming method applied to a radio astronomical aperture array, wherein the computer program causes a computer to execute the adaptive beamforming method for a radio astronomical aperture array as described in any one of claims 1 to 5.

8. An electronic device, characterized in that, include: One or more processors, a memory, and one or more programs, wherein the one or more programs are stored in the memory and configured to be executed by the one or more processors, the programs including methods for performing adaptive beamforming methods for radio astronomy aperture arrays as described in any one of claims 1 to 5.

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