A method for determining the nonlinear frequency offset accumulation of LFM signals in radar equipment

Abstract

This invention discloses a method, system, electronic device, and computer-readable storage medium for determining the cumulative nonlinear frequency offset of an LFM signal from a radar device. The method includes buffering discrete data of the LFM signal to form buffered data; performing data fitting transformation on the buffered data to obtain transformed data; and determining the cumulative nonlinear frequency offset of the LFM signal based on the transformed data. This invention achieves the determination of the cumulative nonlinear frequency offset of the LFM signal from a radar device, solving the problem of low accuracy in determining the cumulative nonlinear frequency offset. It can accurately determine the cumulative nonlinear frequency offset of the LFM signal input to the radar device, meeting the requirements for radar device use.

Description

Technical Field

[0001] This invention relates to a method for determining nonlinear frequency offset accumulation, and more particularly to a method for determining nonlinear frequency offset accumulation of LFM signals from radar equipment, a system for determining nonlinear frequency offset accumulation of LFM signals from radar equipment, an electronic device, and a computer-readable storage medium. Background Technology

[0002] When radar equipment is in operation, it is necessary to determine the cumulative nonlinear frequency offset of the LFM (Linear Frequency Modulation) signal with a V-shaped frequency modulation slope. Traditional methods for determining the cumulative nonlinear frequency offset simply involve performing quadrature mixing on the LFM signal and calculating the cumulative nonlinear frequency offset.

[0003] Traditional methods are simplistic in calculation, but the resulting nonlinear frequency offset cumulative quantity is not very accurate and cannot meet current requirements. Summary of the Invention

[0004] To address the aforementioned problems, this invention provides a method for determining the cumulative nonlinear frequency offset of LFM signals from radar equipment, a system for determining the cumulative nonlinear frequency offset of LFM signals from radar equipment, an electronic device, and a computer-readable storage medium.

[0005] In view of the above, the technical solution provided by the present invention is as follows:

[0006] In a first aspect, a method for determining the cumulative nonlinear frequency offset of an LFM signal from a radar device includes: buffering discrete data of the LFM signal to form buffered data; performing data fitting transformation on the buffered data to obtain transformed data; and determining the cumulative nonlinear frequency offset of the LFM signal based on the transformed data.

[0007] In some embodiments, the step of caching discrete data of the LFM signal to form cached data includes: determining the size of a rectangular window based on the effective time width of the LFM signal; and caching each frame of discrete data containing the LFM signal through the rectangular window to form the cached data.

[0008] In some embodiments, performing data fitting transformation on the cached data to obtain transformed data includes: performing a discrete Hilbert transform on the cached data to obtain transformed result data; obtaining an amplitude based on the cached data and the transformed result data; performing curve fitting based on the amplitude to obtain a fitted curve; and obtaining the transformed data based on the fitted curve.

[0009] In some embodiments, obtaining the transformed data based on the fitted curve includes: extracting data at intervals based on the fitted curve to obtain multiple data points; determining the minimum time-domain data point index value and the maximum time-domain data point index value based on the multiple data points; obtaining a complex sequence based on the cached data, the transformed result data, and the minimum and maximum time-domain data point index values; and splitting the complex sequence into equal-length sequences to obtain a first sequence and a second sequence, which are used as the transformed data.

[0010] In some embodiments, determining the nonlinear frequency offset accumulation of the LFM signal based on the transformed data includes: extracting the phases of the first sequence and the second sequence respectively to obtain a first phase and a second phase; performing curve fitting on the first phase and the second phase respectively to obtain a first curve and a second curve respectively; determining the frequency offsets of the first curve and the second curve respectively to obtain a first frequency offset and a second frequency offset respectively; extracting the frequency offset data of the first frequency offset and the second frequency offset respectively and accumulating them to obtain an accumulated value as the nonlinear frequency offset accumulation.

[0011] Secondly, the present invention also provides a system for determining the nonlinear frequency offset accumulation of an LFM signal in a radar device, comprising: a data buffer module for buffering discrete data of an LFM signal to form buffered data; a data processing module for performing data fitting transformation on the buffered data to obtain transformed data; and a nonlinear frequency offset accumulation determination module for determining the nonlinear frequency offset accumulation of the LFM signal based on the transformed data.

[0012] In some embodiments, the data caching module forms cached data in the following manner: determining the size of a rectangular window based on the effective duration of the LFM signal; and caching each frame of discrete data containing the LFM signal through the rectangular window. This forms the cached data.

[0013] In some embodiments, the data processing module includes: a transformation unit for performing a discrete Hilbert transform on the cached data to obtain transformed result data; an amplitude determination unit for obtaining an amplitude based on the cached data and the transformed result data; a curve fitting unit for performing curve fitting based on the amplitude to obtain a fitted curve; and a data transformation unit for obtaining transformed data based on the fitted curve.

[0014] In some embodiments, the data transformation unit obtains the transformed data in the following manner: based on the fitted curve, data is extracted at intervals to obtain multiple data points; based on the multiple data points, the minimum time-domain data point index value and the maximum time-domain data point index value are determined; based on the cached data and the transformed result data, as well as the minimum time-domain data point index value and the maximum time-domain data point index value, a complex sequence is obtained; the complex sequence is split into equal-length sequences to obtain a first sequence and a second sequence, which serve as the transformed data.

[0015] In some embodiments, the nonlinear frequency offset accumulation determination module determines the nonlinear frequency offset accumulation of the LFM signal in the following manner: extracting the phases of the first sequence and the second sequence respectively to obtain a first phase and a second phase; performing curve fitting on the first phase and the second phase respectively to obtain a first curve and a second curve respectively; determining the frequency offsets of the first curve and the second curve respectively to obtain a first frequency offset and a second frequency offset respectively; extracting the frequency offset data of the first frequency offset and the second frequency offset respectively and accumulating them to obtain an accumulated value as the nonlinear frequency offset accumulation.

[0016] Thirdly, the present invention also provides an electronic device, including at least one processor and at least one memory, wherein the memory stores a computer program, and the processor is configured to read the computer program in the memory and execute the method for determining the cumulative nonlinear frequency offset of the LFM signal of the radar device as described in the first aspect.

[0017] Fourthly, the present invention also provides a computer-readable storage medium storing computer-executable instructions for causing a computer to perform the method for determining the cumulative nonlinear frequency offset of an LFM signal from a radar device as described in the first aspect.

[0018] The present invention achieves the following significant beneficial effects:

[0019] The method of this invention enables the determination of the nonlinear frequency offset accumulation of LFM signals in radar equipment, solving the problem of low accuracy of nonlinear frequency offset accumulation obtained by traditional methods. Theoretical analysis shows that this method is effective and feasible, and can determine the nonlinear frequency offset accumulation of LFM signals input to radar equipment. Currently, this method has been verified in radar equipment prototypes: the determined nonlinear frequency offset accumulation has high accuracy and meets the requirements for use in radar equipment. Attached Figure Description

[0020] Figure 1 This is a schematic flowchart of a method for determining the cumulative nonlinear frequency offset of LFM signals in radar equipment according to some embodiments of the present invention.

[0021] Figure 2 This is a schematic flowchart of a method for determining the cumulative nonlinear frequency offset of LFM signal in radar equipment according to other embodiments of the present invention.

[0022] Figure 3 This is a schematic diagram of the system architecture for determining the cumulative nonlinear frequency offset of LFM signals in radar equipment according to some embodiments of the present invention.

[0023] Figure 4 This is a schematic diagram of the system architecture for determining the cumulative nonlinear frequency offset of the LFM signal in a radar device according to other embodiments of the present invention.

[0024] Figure 5 This is a schematic diagram of an electronic device according to some embodiments of the present invention. Detailed Implementation

[0025] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. The advantages and features of the present invention will become clearer from the following description and claims. It should be noted that the drawings are all in a very simplified form and are not to a precise scale, and are only used to facilitate and clarify the illustration of the embodiments of the present invention.

[0026] It should be noted that, in order to clearly illustrate the content of this invention, several embodiments are provided to further explain different implementations of the invention. These embodiments are enumerated rather than exhaustive. Furthermore, for the sake of brevity, content mentioned in the preceding embodiments is often omitted in the following embodiments. Therefore, content not mentioned in the later embodiments can be referred to in the preceding embodiments.

[0027] While this invention can be extended with various modifications and substitutions, and the specification provides specific embodiments with detailed illustrations, it should be understood that the inventors' intention is not to limit the invention to the specific embodiments described. On the contrary, the inventors' intention is to protect all improvements, equivalent substitutions, and modifications made within the spirit or scope defined by this claim. The same component numbers may be used in all figures to represent the same or similar parts.

[0028] To address the aforementioned technical problems, this invention provides a method for determining the cumulative nonlinear frequency offset of LFM signals in radar equipment, such as... Figure 1 As shown, the method for determining the cumulative nonlinear frequency offset of the LFM signal of radar equipment may include steps S11-S13, which are described in detail below.

[0029] Step S11: The discrete data of the LFM signal is buffered to form buffered data.

[0030] Cache discrete data to facilitate data processing, thereby improving computation speed and result accuracy.

[0031] Step S12: Perform data fitting transformation on the cached data to obtain transformed data.

[0032] Step S13: Based on the transformed data, determine the cumulative nonlinear frequency offset of the LFM signal.

[0033] In this embodiment of the invention, the original data is processed, including fitting and transformation, to obtain transformed data. Based on the transformed data, the linear frequency offset accumulation is determined, thereby greatly improving the reliability and accuracy of the linear frequency offset accumulation and meeting the requirements of radar equipment.

[0034] In some embodiments, the present invention may first construct a nonlinear frequency offset accumulation determination system. This system includes a data caching module, a data processing module, and a nonlinear frequency offset accumulation determination module, which are respectively used to execute steps S11, S12, and S13.

[0035] In some embodiments, step S11, which involves buffering the discrete data of the LFM signal to form buffered data, may include: determining the size of a rectangular window based on the effective time width of the LFM signal; and buffering each frame of discrete data containing the LFM signal through the rectangular window to form buffered data.

[0036] In this embodiment of the invention, a rectangular window is used to buffer a frame of discrete data of an LFM signal containing a V-shaped frequency modulation slope, forming buffered data x(n1), and the width T of the rectangular window is set. r >T s This ensures that all valid data of the V-mode frequency modulation slope LFM signal are within the rectangular window, where T s The effective time width of the V-type LFM signal is given by n1, where n1 is the index value of the time-domain data point, n1 = 1, 2, ..., N1; and N1 is the length of the buffered data, N1 = f s ·T r f s This refers to the rate at which the buffered data is stored. This embodiment ensures that all discrete data from each frame of the LFM signal is stored in the buffer, facilitating subsequent data processing.

[0037] In some embodiments, such as Figure 2As shown, step S12, which involves performing data fitting transformation on the cached data to obtain transformed data, may include: step S121, performing a discrete Hilbert transform on the cached data to obtain transformed result data; step S122, obtaining the amplitude based on the cached data and the transformed result data; step S123, performing curve fitting based on the amplitude to obtain a fitted curve; and step S124, obtaining transformed data based on the fitted curve.

[0038] In this embodiment of the invention, a discrete Hilbert transform is performed on the cached data x(n1) to obtain the transformed result x. h (n1); Calculate the amplitude A(n1): Polynomial curve fitting is performed on A(n1), with the polynomial degree set to p, to obtain the fitted curve α(t); based on the fitted curve, the transformation data is determined, thereby ensuring the reliability of the data and improving the accuracy of the data.

[0039] In some embodiments, step S124, obtaining transformed data based on the fitted curve, may include: extracting data at intervals based on the fitted curve to obtain multiple data points; determining the minimum time-domain data point index value and the maximum time-domain data point index value based on the multiple data points; obtaining a complex sequence based on the cached data, the transformed result data, and the minimum and maximum time-domain data point index values; and splitting the complex sequence into equal-length sequences to obtain a first sequence and a second sequence, which serve as the transformed data.

[0040] In this embodiment of the invention, data can be extracted from the fitted curve α(t) at N1-point intervals, where the extraction can be at equal intervals, to obtain data β(n1), where t is a time parameter; the minimum time-domain data point index value corresponding to the data satisfying β(n1)≥0.8β0 is found, denoted as z1, and the maximum time-domain data point index value corresponding to the data satisfying β(n1)≥0.8β0 is found, denoted as z2; the complex sequence x(n1)+j·x is extracted. h Given z1 ≤ z1 ≤ z2, we obtain the complex sequence y(n2), where β0 is the maximum value of the data β(n1); n2 is the index value of the time-domain data point, n2 = 1, 2, ..., N2; N2 is the length of the effective data, N2 = z2 - z1 + 1. The complex sequence y(n2) is then split into equal-length segments. The first half of the data is extracted to form the complex sequence s1(n3), and the second half is extracted to form the complex sequence s2(n3), where n3 is the index value of the time-domain data point, n3 = 1, 2, ..., N2 / 2. Through the data processing method of this embodiment, the obtained transformed data can better calculate the nonlinear frequency offset accumulation, ensuring the accuracy of the nonlinear frequency offset accumulation.

[0041] In some embodiments, step S13, determining the nonlinear frequency offset accumulation of the LFM signal based on the transformed data, may include: extracting the phases of the first sequence and the second sequence respectively to obtain the first phase and the second phase; performing curve fitting on the first phase and the second phase respectively to obtain the first curve and the second curve respectively; determining the frequency offset of the first curve and the second curve respectively to obtain the first frequency offset and the second frequency offset respectively; extracting the frequency offset data of the first frequency offset and the second frequency offset respectively and accumulating them to obtain the accumulated value as the nonlinear frequency offset accumulation.

[0042] In this embodiment of the invention, the phases of the complex sequences s1(n3) and s2(n3) are extracted respectively. and

[0043]

[0044] Set the polynomial degree to q, and then... and Polynomial curve fitting is performed to obtain the fitted curves γ1(t) and γ2(t); the frequency offsets λ1(t) and λ2(t) are calculated respectively:

[0045] λ1(t)=[γ1(t)]′-(f0-kt), λ2(t)=[γ2(t)]′-(f0+kt),

[0046] Data is extracted at N2 / 2 equal intervals for frequency offsets λ1(t) and λ2(t) respectively, and all data are accumulated. The accumulated value is the nonlinear frequency offset accumulation, where f0 is the center frequency of the LFM signal, k is the absolute value of the LFM signal frequency modulation slope, real[·] represents the operation of taking the real part of the complex number, and imag[·] represents the operation of taking the imaginary part of the complex number.

[0047] The above method enables the determination of the nonlinear frequency offset accumulation of the LFM signal of radar equipment, solving the problem of low accuracy of the nonlinear frequency offset accumulation obtained by traditional methods. The determined nonlinear frequency offset accumulation has high accuracy and meets the requirements of radar equipment.

[0048] Based on the same inventive concept, the present invention also provides a system 100 for determining the cumulative nonlinear frequency offset of LFM signals in radar equipment, such as... Figure 3 As shown, the present invention also provides a radar equipment LFM signal nonlinear frequency offset accumulation determination system 100, which may include: a data buffer module 110 for buffering discrete data of LFM signal to form buffered data; a data processing module 120 for performing data fitting transformation on the buffered data to obtain transformed data; and a nonlinear frequency offset accumulation determination module 130 for determining the nonlinear frequency offset accumulation of LFM signal based on the transformed data.

[0049] In some embodiments, the data caching module 110 forms cached data in the following manner: determining the size of a rectangular window based on the effective duration of the LFM signal; and caching each frame of discrete data containing the LFM signal through the rectangular window.

[0050] In some embodiments, such as Figure 4 As shown, the data processing module 120 may include: a transformation unit 121, used to perform a discrete Hilbert transform on the cached data to obtain the transformed result data; an amplitude determination unit 122, used to obtain the amplitude based on the cached data and the transformed result data; a curve fitting unit 123, used to perform curve fitting based on the amplitude to obtain the fitted curve; and a data transformation unit 124, used to obtain the transformed data based on the fitted curve.

[0051] In some embodiments, the data transformation unit 124 may obtain transformed data in the following manner: based on the fitted curve, data is extracted at intervals to obtain multiple data points; based on the multiple data points, the minimum time-domain data point index value and the maximum time-domain data point index value are determined; based on the cached data and the transformed result data, as well as the minimum time-domain data point index value and the maximum time-domain data point index value, a complex sequence is obtained; the complex sequence is split into equal lengths to obtain a first sequence and a second sequence, which are used as transformed data.

[0052] In some embodiments, the nonlinear frequency offset accumulation determination module 130 may determine the nonlinear frequency offset accumulation of the LFM signal in the following manner: extract the phases of the first sequence and the second sequence respectively to obtain the first phase and the second phase respectively; perform curve fitting on the first phase and the second phase respectively to obtain the first curve and the second curve respectively; determine the frequency offset of the first curve and the second curve respectively to obtain the first frequency offset and the second frequency offset respectively; extract the frequency offset data of the first frequency offset and the second frequency offset respectively and accumulate them to obtain the accumulated value as the nonlinear frequency offset accumulation.

[0053] The specific implementation and related effects of the above-mentioned radar equipment LFM signal nonlinear frequency offset cumulative amount determination system 100 have been described in the relevant embodiments of the aforementioned radar equipment LFM signal nonlinear frequency offset cumulative amount determination method, and will not be repeated here.

[0054] Based on the same inventive concept, the present invention also provides an electronic device 400, such as... Figure 5 As shown, the electronic device 400 may include at least one processor 410 and at least one memory 420, wherein the memory stores a computer program, and the processor is used to read the computer program in the memory and execute the radar device LFM signal nonlinear frequency offset accumulation determination method as in any of the foregoing embodiments.

[0055] Based on the same inventive concept, the present invention also provides a computer-readable storage medium storing computer-executable instructions for causing a computer to perform the method for determining the cumulative nonlinear frequency offset of the LFM signal of a radar device as described in any of the foregoing embodiments.

[0056] The specific implementation methods and related effects of the above electronic devices and computer-readable storage media have been described in the foregoing related embodiments, and will not be repeated here.

[0057] The present invention achieves the following significant beneficial effects:

[0058] This method solves the problem of low accuracy of nonlinear frequency offset accumulation obtained by traditional methods. After theoretical analysis, it is believed that this method is effective and feasible, and can determine the nonlinear frequency offset accumulation of LFM signals input to radar equipment. Currently, this method has been verified in radar equipment prototypes: the determined nonlinear frequency offset accumulation has high accuracy and meets the requirements of radar equipment use.

[0059] Obviously, the above embodiments are merely illustrative examples for clear explanation and not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations. However, obvious variations or modifications derived therefrom still fall within the scope of protection of this invention.

Claims

1. A method for determining the cumulative nonlinear frequency offset of LFM signals in radar equipment, characterized in that, The method for determining the cumulative nonlinear frequency offset of the LFM signal of the radar equipment includes: The size of the rectangular window is determined based on the effective duration of the LFM signal; The rectangular window is used to buffer each frame of discrete data containing the LFM signal to form buffered data. Perform a discrete Hilbert transform on the cached data to obtain the transformed data; The amplitude is obtained based on the cached data and the transformation result data; Based on the amplitude, a curve is fitted to obtain the fitted curve; Based on the fitted curve, data is extracted at intervals to obtain multiple data points. Based on these multiple data points, the minimum and maximum time-domain data point index values ​​are determined. Based on the cached data, the transformed result data, and the minimum and maximum time-domain data point index values, a complex sequence is obtained. The complex sequence is then split into equal-length segments to obtain a first sequence and a second sequence, which serve as the transformed data. The phases of the first sequence and the second sequence are extracted respectively to obtain the first phase and the second phase accordingly; Curve fitting is performed on the first phase and the second phase respectively to obtain the first curve and the second curve; The frequency offsets of the first curve and the second curve are determined respectively, and the first frequency offset and the second frequency offset are obtained accordingly. Frequency offset data of the first frequency offset and the second frequency offset are extracted and accumulated to obtain the accumulated value, which is used as the nonlinear frequency offset accumulation.

2. A system for determining the cumulative nonlinear frequency offset of LFM signals in radar equipment, characterized in that, The radar equipment LFM signal nonlinear frequency offset cumulative determination system includes: The data caching module is used to determine the size of the rectangular window based on the effective time width of the LFM signal; it is also used to cache each frame of discrete data containing the LFM signal through the rectangular window to form cached data. The data processing module is configured to perform a discrete Hilbert transform on the cached data to obtain transformed result data; to obtain an amplitude based on the cached data and the transformed result data; to perform curve fitting based on the amplitude to obtain a fitted curve; and to perform interval extraction of data based on the fitted curve to obtain multiple data points, determine the minimum and maximum time-domain data point index values ​​based on the multiple data points, obtain a complex sequence based on the cached data, the transformed result data, and the minimum and maximum time-domain data point index values; and to split the complex sequence into equal-length sequences to obtain a first sequence and a second sequence, which serve as transformed data. The nonlinear frequency offset accumulation determination module is used to extract the phases of the first sequence and the second sequence respectively, and obtain the first phase and the second phase accordingly; to perform curve fitting on the first phase and the second phase respectively, and obtain the first curve and the second curve accordingly; to determine the frequency offset of the first curve and the second curve respectively, and obtain the first frequency offset and the second frequency offset accordingly; and to extract the frequency offset data of the first frequency offset and the second frequency offset respectively and accumulate them to obtain the accumulated value as the nonlinear frequency offset accumulation.

3. An electronic device, characterized in that, It includes at least one processor and at least one memory, wherein the memory stores a computer program, and the processor is used to read the computer program in the memory and execute the method for determining the cumulative nonlinear frequency offset of the LFM signal of the radar device as described in claim 1.

4. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores computer-executable instructions for causing a computer to execute the method for determining the cumulative nonlinear frequency offset of the LFM signal of a radar device as described in claim 1.

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