Direction finding method and device based on subarray-level digital multiple beams

Abstract

The invention discloses a direction finding method and device based on subarray-level digital multiple beams, and the method comprises the steps: converting an intermediate frequency signal of each subarray into a digital signal through a digital collection channel of the subarray; setting beam positions according to wide angle intervals to generate a multi-beam weighting coefficient table, and performing simultaneous complex weighted summation processing on all digital channelized signals of the sub-arrays to generate original beam signal data of the sub-arrays; adjacent beams are added and multiplied by a beam adjustment coefficient to generate derivative beam data. A two-dimensional multi-beam amplitude-comparison direction-finding method is adopted to calculate an actual target signal azimuth angle and a pitching angle; and summarizing all digital channelization processing results of the azimuth angle and the pitch angle of the actual target signal, and integrating with a pulse description word result of the reconnaissance and direction finding system to form a reconnaissance and direction finding result of each digital channel. The method has the advantages that the direction finding precision and the instantaneous airspace coverage rate index of the reconnaissance and direction finding system can be greatly improved under the condition that the hardware architecture of the current reconnaissance and direction finding system is not changed.

Description

Technical Field

[0001] The invention relates to a direction finding method and device based on subarray-level digital multi-beam, belonging to the technical field of wireless reconnaissance and direction finding such as radar and communication. Background Art

[0002] Direction finding algorithms are an important application in the field of wireless reconnaissance and direction finding such as radar and communications. Traditional subarray-level digital beam direction finding algorithms generally use multi-beam amplitude comparison method, sum-difference angle measurement method, and super-resolution array signal processing algorithm. The super-resolution array signal processing algorithm can be further divided into MUSIC algorithm, ESPRIT algorithm, WSF algorithm, and MVDR algorithm. The multi-beam amplitude comparison method has a small amount of calculation but can achieve instantaneous wide spatial domain coverage. The sum-difference angle measurement method has a small amount of calculation but a narrow instantaneous spatial domain coverage range, which is not suitable for wide spatial domain signal search; the super-resolution array signal processing algorithm has the largest amount of calculation and requires the most resources, but can achieve wide spatial domain coverage and high-precision measurement. In actual engineering applications, considering the needs of wide-bandwidth and wide-angle instantaneous reconnaissance and direction finding, the current hardware and software computing resources cannot well support the application of super-resolution array signal processing algorithms. The multi-beam amplitude comparison method is generally used for wide-bandwidth and wide-angle instantaneous reconnaissance and direction finding.

[0003] When the traditional sub-array-level digital multi-beam direction-finding algorithm is applied in a wide frequency band, such as 64-channel parallel processing under 1GHZ instantaneous bandwidth, it is impossible to form a large number of digital beams at the same time due to the limitation of hardware computing resources such as FPGA, resulting in a small number of digital beams and the inability to achieve wide spatial coverage. In addition, the small number of beams will also affect the direction-finding accuracy, resulting in a decrease in the overall performance of the reconnaissance and direction-finding system. Summary of the invention

[0004] The technical problem to be solved by the present invention is to overcome the defects of the prior art and provide a direction finding method and device based on subarray-level digital multi-beam.

[0005] In order to solve the above technical problems, the present invention provides a direction finding method based on subarray-level digital multi-beam, comprising:

[0006] The intermediate frequency signal of each sub-array is converted into a digital signal through the digital acquisition channel of the sub-array;

[0007] For the digital channel corresponding to the RF channel received by each sub-array, a multi-beam weight coefficient table is generated according to the wide angle interval setting beam position, and all digital channelized digital signals of the sub-array are processed by complex weighted summation at the same time, and the original beam signal data of the sub-array is generated at the same time;

[0008] According to the original multi-beam complex signal data of the generated sub-array, for each digital channel, the derivative beam data is generated by adding adjacent beams and multiplying by a beam adjustment coefficient;

[0009] According to the original beam signal data and derived beam data of the subarray, for each digital channel, after the two-dimensional direction finding multi-beam is arranged in a matrix, the actual target signal azimuth angle and elevation angle are calculated according to the two-dimensional multi-beam amplitude ratio method;

[0010] All digital channel processing results of the actual target signal azimuth angle and elevation angle within the instantaneous bandwidth are summarized and integrated with the pulse description word results of the reconnaissance and direction finding system itself to form the reconnaissance and direction finding results of each digital channel.

[0011] Furthermore, the converting of the intermediate frequency signal of each sub-array into a digital signal through the digital acquisition channel of the sub-array includes:

[0012] The intermediate frequency signals collected by the digital acquisition channels of the sub-arrays are processed in sequence, including data denoising, filtering, digital down-conversion, and digital channelization, to obtain the real and imaginary data of multiple digital channelized zero intermediate frequency time domains of each sub-array.

[0013] Furthermore, the beam adjustment coefficient is obtained by simulation according to advance theoretical calculation.

[0014] Furthermore, the beam adjustment coefficient is obtained by theoretical calculation and simulation in advance, including:

[0015] First, according to the theoretical formula of phased array digital beamforming, the weighted coefficients of all digitally formed main beams are calculated. Then, by selecting the normalized weighted coefficients of the upper and lower adjacent beams or the left and right adjacent beams in the main beam, the two sets of normalized weighted coefficients are added and divided by two to obtain a derivative beam non-normalized weighted coefficient. Then, the maximum amplitude of the newly obtained derivative beam weighted coefficient is calculated to obtain the maximum amplitude A. n , then the derivative beam adjustment coefficient is expressed as 1 / A n .

[0016] Furthermore, the actual angle is calculated according to the two-dimensional multi-beam amplitude ratio method, including:

[0017] First, find the maximum signal and determine whether the maximum signal meets the receiving sensitivity requirements. If it meets the sensitivity requirements, extract the amplitude values ​​of the four beam signals on the left and right and above and below the maximum amplitude beam, and calculate the actual angle through the three-point fitting method in two dimensions.

[0018] A direction finding device based on subarray-level digital multi-beam, comprising:

[0019] A conversion module, used for converting the intermediate frequency signal of each sub-array into a digital signal through a digital acquisition channel of the sub-array;

[0020] The first generation module generates a multi-beam weight coefficient table for the digital channel corresponding to the radio frequency channel received by each sub-array according to the wide angle interval setting beam position, performs simultaneous complex weighted summation processing on all digital channelized digital signals of the sub-array, and generates sub-array original beam signal data at the same time;

[0021] A second generating module is used to generate derivative beam data for each digital channel by adding adjacent beams and multiplying by a beam adjustment coefficient according to the generated sub-array original multi-beam complex signal data;

[0022] The calculation module is used to calculate the actual target signal azimuth angle and elevation angle according to the two-dimensional multi-beam amplitude ratio method for each digital channel after performing matrix arrangement according to the two-dimensional direction finding multi-beam according to the sub-array original beam signal data and the derived beam data;

[0023] The integration module is used to summarize all digital channelization processing results of the actual target signal azimuth angle and elevation angle within the instantaneous bandwidth, and integrate them with the pulse description word results of the reconnaissance and direction finding system itself to form the reconnaissance and direction finding results of each digital channel.

[0024] A computer-readable storage medium storing one or more programs, wherein the one or more programs include instructions, which, when executed by a computing device, cause the computing device to perform the method.

[0025] A computer device, comprising:

[0026] 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, and the one or more programs include instructions for executing the method.

[0027] The beneficial effects achieved by the present invention are:

[0028] The main feature of the present invention is that it achieves performance improvement of the traditional sub-array-level digital multi-beam reconnaissance and direction-finding system without increasing hardware resources. Specifically, in the case of less computing resources, by proposing a digital derivative beam algorithm, based on the original digital beam signal data, simple addition and multiple operations can be used to automatically generate other digital direction-finding beams, thereby effectively improving the instantaneous coverage range and direction-finding accuracy of the downward airspace of broadband reconnaissance and direction-finding. This technology can be widely used in sub-array-level digital multi-beam direction-finding systems. Without changing the hardware architecture of the current reconnaissance and direction-finding system, the direction-finding accuracy and instantaneous airspace coverage rate indicators of the reconnaissance and direction-finding system can be greatly improved by updating the software direction-finding algorithm. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1It is a schematic diagram of the process of the present invention;

[0030] Figure 2 is a schematic diagram of the derived beam. DETAILED DESCRIPTION

[0031] The present invention will be further described below in conjunction with the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present invention, and cannot be used to limit the protection scope of the present invention.

[0032] Example 1

[0033] This embodiment introduces a direction-finding method based on subarray-level digital multi-beam, which can solve the problem of how to automatically generate other direction-finding beams through a new algorithm when computing resources are limited, so that more multi-beams can be generated digitally and the generation speed is faster. At the same time, two-dimensional precise direction-finding is achieved through a three-point fitting method of amplitude ratio. Compared with the traditional subarray-level digital multi-beam direction-finding algorithm, the direction-finding algorithm of the present invention processes faster, requires fewer resources, and can simultaneously perform wide spatial domain, wide frequency band, and high-precision direction-finding. It is suitable for improving the coverage area and accuracy of direction-finding through simple digital processing as much as possible without changing the hardware of the signal processing board;

[0034] like Figure 1 As shown, the following steps are included:

[0035] The intermediate frequency signal of each sub-array is converted into a digital signal through the digital acquisition channel of the sub-array;

[0036] For the digital channel corresponding to the RF channel received by each sub-array, a multi-beam weight coefficient table is generated according to the wide angle interval setting beam position, and all digital channelized digital signals of the sub-array are processed by complex weighted summation at the same time, and the original beam signal data of the sub-array is generated at the same time;

[0037] According to the original multi-beam complex signal data of the generated sub-array, for each digital channel, the derivative beam data is generated by adding adjacent beams and multiplying by a beam adjustment coefficient;

[0038] According to the original beam signal data and derived beam data of the subarray, for each digital channel, after the two-dimensional direction finding multi-beam is arranged in a matrix, the actual target signal azimuth angle and elevation angle are calculated according to the two-dimensional multi-beam amplitude ratio method;

[0039] All digital channel processing results of the actual target signal azimuth angle and elevation angle within the instantaneous bandwidth are summarized and integrated with the pulse description word results of the reconnaissance and direction finding system itself to form the reconnaissance and direction finding results of each digital channel.

[0040] Specifically, they include:

[0041] 1) Preprocessing stage: The intermediate frequency signals of each sub-array are converted into digital signals through the digital acquisition channel of the sub-array. Preprocessing is first performed, including data denoising, filtering, digital down-conversion, and digital channelization processing, to obtain the real and imaginary data of multiple digital channelized zero intermediate frequency time domains of each sub-array.

[0042] 2) Subarray original beamforming. When generating beams, it is necessary to enlarge the angular intervals between the beams so that the initially generated beams cover a larger spatial range, without having to consider that the overlap between beams does not meet the 3dB amplitude requirement. For each digital channel, a multi-beam weighting coefficient table is generated based on the wide angular interval setting of the beam position, and all digital channelized digital signals of the subarray are simultaneously processed by complex weighted summation, and the original beam signal data of the subarray is generated at the same time. Generally, for two-dimensional subarrays and digital arrays, assuming that the number of subarrays is 16, 64-channel digital channelization processing is performed at an instantaneous bandwidth of 1GHz. Generally, two high-performance signal processing boards can realize 16 beams at the same time.

[0043] 3) Derivative beam generation: Based on the original multi-beam complex signal data of the generated subarray, for each digital channel, the required intermediate direction finding beams are generated by adding adjacent beams and multiplying them by a beam adjustment coefficient. The derivative beams are corrected according to the beam adjustment coefficients obtained by theoretical calculation and simulation in advance, so that the amplitude of the derivative beam measurement signal is consistent with the actual beam amplitude at the pointing position, so as to perform multi-beam amplitude comparison direction finding. The schematic diagram of the derivative beam is shown in Figure 2 shown.

[0044] The acquisition of the beam adjustment coefficient includes: firstly, calculating the weighted coefficients of all digitally formed main beams according to the theoretical formula of phased array digital beam forming, then selecting the normalized weighted coefficient results of the upper and lower adjacent beams or the left and right adjacent beams in the main beam, adding the two groups of normalized weighted coefficients and dividing them by two to obtain a derivative beam non-normalized weighted coefficient, and then performing maximum amplitude calculation on the newly obtained derivative beam weighted coefficient to obtain the maximum amplitude A n , then the derivative beam adjustment coefficient is expressed as 1 / A n By using the above method, the derivative beam adjustment coefficients are calculated for all the normalized weighted coefficients of the upper and lower adjacent beams and the left and right adjacent beams in the main beam, and all the derivative beam adjustment coefficients can be obtained. In this way, through the limited digital main beam signal, a group of beam signals can be derived by simple addition and multiplication operations on the upper and lower adjacent main beams and the left and right adjacent main beams, and the reconnaissance direction finding system can be used for multi-beam amplitude comparison direction finding processing.

[0045] 4) Calculation by the three-point fitting method: Based on the original beam signal data and derived beam data of the subarray, for each digital channel, a matrix arrangement is performed according to the two-dimensional direction finding multi-beam. According to the two-dimensional multi-beam amplitude ratio method, the maximum signal is first found to determine whether the maximum signal fully meets the receiving sensitivity requirements. If the sensitivity requirements are met, the values ​​of the four beams on the left and right and above and below the maximum amplitude beam are extracted, and the actual angle is calculated through the three-point fitting method in two dimensions.

[0046] 5) Summarize the processing results of each channel and integrate them with the pulse description word results obtained by the digital channelized pulse reconnaissance system to form the reconnaissance and direction finding results of each channel, which are sent to the command and control system for subsequent data processing and display.

[0047] Example 2

[0048] Based on the same inventive concept as that of Embodiment 1, this embodiment introduces a direction finding device based on subarray-level digital multi-beam, including:

[0049] A conversion module, used for converting the intermediate frequency signal of each sub-array into a digital signal through a digital acquisition channel of the sub-array;

[0050] The first generation module generates a multi-beam weight coefficient table for the digital channel corresponding to the radio frequency channel received by each sub-array according to the wide angle interval setting beam position, performs simultaneous complex weighted summation processing on all digital channelized digital signals of the sub-array, and generates sub-array original beam signal data at the same time;

[0051] A second generating module is used to generate derivative beam data for each digital channel by adding adjacent beams and multiplying by a beam adjustment coefficient according to the generated sub-array original multi-beam complex signal data;

[0052] The calculation module is used to calculate the actual target signal azimuth angle and elevation angle according to the two-dimensional multi-beam amplitude ratio method for each digital channel after performing matrix arrangement according to the two-dimensional direction finding multi-beam according to the sub-array original beam signal data and the derived beam data;

[0053] The integration module is used to summarize all digital channelization processing results of the actual target signal azimuth angle and elevation angle within the instantaneous bandwidth, and integrate them with the pulse description word results of the reconnaissance and direction finding system itself to form the reconnaissance and direction finding results of each digital channel.

[0054] Example 3

[0055] Based on the same inventive concept as other embodiments, this embodiment introduces a computer-readable storage medium storing one or more programs, characterized in that the one or more programs include instructions that, when executed by a computing device, enable the computing device to execute the method.

[0056] Example 4

[0057] Based on the same inventive concept as other embodiments, this embodiment introduces a computer device, including:

[0058] 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, and the one or more programs include instructions for executing the method.

[0059] Those skilled in the art will appreciate that embodiments of the present invention may be provided as methods, systems, or computer program products. Therefore, the present invention may take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware. Moreover, the present invention may take 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 code.

[0060] The present invention is described with reference to flowcharts and / or block diagrams of methods, devices (systems), and computer program products according to embodiments of the present invention. It should be understood that each process and / or block in the flowchart and / or block diagram, as well as the combination of processes and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0061] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0062] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1The steps for the functions specified in one or more boxes.

[0063] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the technical principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A direction finding method based on subarray-level digital multi-beam, characterized in that: include: The intermediate frequency signal of each sub-array is converted into a digital signal through the digital acquisition channel of the sub-array; For the digital channel corresponding to the RF channel received by each sub-array, a multi-beam weight coefficient table is generated according to the wide angle interval setting beam position, and all digital channelized digital signals of the sub-array are processed by complex weighted summation at the same time, and the original beam signal data of the sub-array is generated at the same time; According to the original multi-beam complex signal data of the generated sub-array, for each digital channel, the derivative beam data is generated by adding adjacent beams and multiplying by a beam adjustment coefficient; According to the original beam signal data and derived beam data of the subarray, for each digital channel, after the two-dimensional direction finding multi-beam is arranged in a matrix, the actual target signal azimuth angle and elevation angle are calculated according to the two-dimensional multi-beam amplitude ratio method; All digital channel processing results of the actual target signal azimuth angle and elevation angle within the instantaneous bandwidth are summarized and integrated with the pulse description word results of the reconnaissance and direction finding system itself to form the reconnaissance and direction finding results of each digital channel.

2. The direction finding method based on subarray-level digital multi-beam according to claim 1, characterized in that: The step of converting the intermediate frequency signal of each sub-array into a digital signal through the digital acquisition channel of the sub-array includes: The intermediate frequency signals collected by the digital acquisition channels of the sub-arrays are processed in sequence, including data denoising, filtering, digital down-conversion, and digital channelization, to obtain the real and imaginary data of multiple digital channelized zero intermediate frequency time domains of each sub-array.

3. The direction finding method based on subarray-level digital multi-beam according to claim 1, characterized in that: The beam adjustment coefficient is obtained by simulation according to advance theoretical calculation.

4. The direction finding method based on subarray-level digital multi-beam according to claim 3, characterized in that: The beam adjustment coefficient is obtained by simulation according to advance theoretical calculation, including: First, according to the theoretical formula of phased array digital beamforming, the weighted coefficients of all digitally formed main beams are calculated. Then, by selecting the normalized weighted coefficients of the upper and lower adjacent beams or the left and right adjacent beams in the main beam, the two sets of normalized weighted coefficients are added and divided by two to obtain a derivative beam non-normalized weighted coefficient. Then, the maximum amplitude of the newly obtained derivative beam weighted coefficient is calculated to obtain the maximum amplitude A. n , then the derivative beam adjustment coefficient is expressed as 1 / A n .

5. The direction finding method based on subarray-level digital multi-beam according to claim 1, characterized in that: The actual angle is calculated according to the two-dimensional multi-beam amplitude comparison method, including: First, find the maximum signal and determine whether the maximum signal meets the receiving sensitivity requirements. If it meets the sensitivity requirements, extract the amplitude values ​​of the four beam signals on the left and right and above and below the maximum amplitude beam, and calculate the actual angle through the three-point fitting method in two dimensions.

6. A direction finding device based on subarray-level digital multi-beam, characterized in that: include: A conversion module, used for converting the intermediate frequency signal of each sub-array into a digital signal through a digital acquisition channel of the sub-array; The first generation module generates a multi-beam weight coefficient table for the digital channel corresponding to the radio frequency channel received by each sub-array according to the wide angle interval setting beam position, performs simultaneous complex weighted summation processing on all digital channelized digital signals of the sub-array, and generates sub-array original beam signal data at the same time; A second generating module is used to generate derivative beam data for each digital channel by adding adjacent beams and multiplying by a beam adjustment coefficient according to the generated sub-array original multi-beam complex signal data; The calculation module is used to calculate the actual target signal azimuth angle and elevation angle according to the two-dimensional multi-beam amplitude ratio method for each digital channel after performing matrix arrangement according to the two-dimensional direction finding multi-beam according to the sub-array original beam signal data and the derived beam data; The integration module is used to summarize all digital channelization processing results of the actual target signal azimuth angle and elevation angle within the instantaneous bandwidth, and integrate them with the pulse description word results of the reconnaissance and direction finding system itself to form the reconnaissance and direction finding results of each digital channel.

7. A computer-readable storage medium storing one or more programs, characterized in that: The one or more programs include instructions which, when executed by a computing device, cause the computing device to perform the method of any one of claims 1 to 5.

8. A computer 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, and the one or more programs include instructions for executing any of the methods described in claims 1 to 5.

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