A device and method for generating a broadband narrow-pulse linear frequency modulated signal correction sequence.

Abstract

This invention relates to a device and method for generating a correction sequence for a wideband narrow-pulse linear frequency modulated (LFM) signal, aiming to solve the problem of large deviations in the correction sequences of wideband narrow-pulse LFM signals generated in the prior art. The device for generating a wideband narrow-pulse LFM signal correction sequence includes: a baseband data generation module, an orthogonal modulation module, and a correction sequence generation module. The baseband data generation module is connected to the orthogonal modulation module, and the orthogonal modulation module is also connected to the correction sequence generation module. The baseband data generation module generates baseband data for a LFM signal with a large time width. The orthogonal modulation module performs digital-to-analog conversion on the baseband data and orthogonally modulates the conversion result to generate a LFM signal with a large time width. The correction sequence generation module generates a correction sequence for a LFM signal with a smaller time width based on the LFM signal with a large time width.

Description

Technical Field

[0001] This invention relates to the field of pulse linear frequency modulation (LFM) signal correction technology, and specifically to a broadband narrow pulse LFM signal correction sequence generation device and method. Background Technology

[0002] During terminal guidance in radar-specific testing equipment, a correction sequence for a wideband, narrow-pulse linear frequency modulated (LFM) signal is required. This sequence can be used to correct LFM pulse signals with significant phase errors. A common method for generating LFM signal correction sequences involves first using a mathematical model of the LFM baseband complex signal to generate the LFM baseband complex signal. The real and imaginary parts are extracted and scaled to form in-phase and quadrature data. The in-phase and quadrature data are then converted from digital to analog to form in-phase and quadrature baseband analog signals. These analog signals are then low-pass filtered, followed by quadrature modulation and band-pass filtering to obtain the LFM signal. Finally, the LFM signal is discretized to form discrete data, which is then processed to obtain the correction sequence. When generating a broadband narrow-pulse linear frequency modulated (LFM) pulse signal correction sequence using this method, a broadband narrow-pulse LFM signal with a small time width is directly generated, discretized to form discrete data, and then processed to obtain the correction sequence. However, due to the limited number of discrete data points in the narrow pulse, the leading and trailing edges of the pulse are difficult to determine precisely, resulting in a certain degree of deviation in the generated broadband narrow-pulse LFM pulse signal correction sequence. Therefore, a broadband narrow-pulse LFM pulse signal correction method is urgently needed to solve the problem of deviation in the broadband narrow-pulse LFM pulse signal correction sequence. Summary of the Invention

[0003] This invention provides a device and method for generating a broadband narrow-pulse linear frequency modulation (LFM) signal correction sequence, aiming to solve the problem of large deviations in the broadband narrow-pulse LFM signal correction sequences generated in the prior art.

[0004] On the one hand, a broadband narrow-pulse linear frequency modulation signal correction sequence generation device is provided, characterized in that it includes:

[0005] The system includes a baseband data generation module, a quadrature modulation module, and a correction sequence generation module, wherein the baseband data generation module is connected to the quadrature modulation module, and the quadrature modulation module is connected to the correction sequence generation module.

[0006] The baseband data generation module is used to generate linear frequency modulation signal baseband data with a relatively long time width.

[0007] The quadrature modulation module is used to perform digital-to-analog conversion on baseband data, and to perform quadrature modulation on the conversion result to generate a linear frequency modulation signal with a large time width.

[0008] The correction sequence generation module is used to generate a correction sequence for a linear frequency modulated signal with a shorter time width based on the linear frequency modulated signal with a longer time width.

[0009] On the other hand, a method for generating a broadband narrow-pulse linear frequency modulated signal correction sequence is provided, characterized by comprising:

[0010] The baseband data generation module generates linear frequency modulated signal baseband data with a relatively large time width.

[0011] The quadrature modulation module performs digital-to-analog conversion on the baseband data, and performs quadrature modulation on the conversion result to generate a linear frequency modulation signal with a large time width;

[0012] The correction sequence generation module generates a correction sequence for the linear frequency modulated signal with a shorter time width based on the linear frequency modulated signal with a longer time width.

[0013] The present invention provides a broadband narrow-pulse linear frequency modulated (LFM) signal correction sequence generation device and method. By processing the LFM signal, an effective broadband narrow-pulse LFM signal correction sequence generation device is provided. The generation device provided by the present invention can reduce the deviation between the generated broadband narrow-pulse LFM signal correction sequence and the theoretical value, thereby improving the accuracy of terminal guidance in radar-specific testing equipment. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the structure of a broadband narrow pulse linear frequency modulation signal correction sequence generation device according to an embodiment of the present invention;

[0015] Figure 2 This is a flowchart illustrating the implementation of a broadband narrow-pulse linear frequency modulated signal correction sequence generation method according to an embodiment of the present invention. Detailed Implementation

[0016] The specific embodiments of the present invention will now be described in detail with reference to the accompanying drawings. Specific details such as particular system structures, models, and technical parameters mentioned in the following description are merely illustrative of the specific embodiments and not intended to limit the scope of protection of the present invention. Furthermore, content that should be known and understood by those skilled in the art will not be repeated here.

[0017] Additionally, it should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of the embodiments of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments described herein can be implemented in a sequence other than that illustrated or described herein.

[0018] In this embodiment of the invention, to address the problem of large deviations in the correction sequence of a wideband narrow-pulse linear frequency modulated (LFM) signal, a wideband narrow-pulse LFM signal correction sequence generation device is provided, such as... Figure 1 As shown, it includes:

[0019] The system includes a baseband data generation module 11, a quadrature modulation module 12, and a correction sequence generation module 13, wherein the baseband data generation module is connected to the quadrature modulation module, and the quadrature modulation module is connected to the correction sequence generation module.

[0020] The baseband data generation module is used to generate linear frequency modulation signal baseband data with a relatively long time width.

[0021] The quadrature modulation module is used to perform digital-to-analog conversion on baseband data, and to perform quadrature modulation on the conversion result to generate a linear frequency modulation signal with a large time width.

[0022] The correction sequence generation module is used to generate a correction sequence for a linear frequency modulated signal with a shorter time width based on the linear frequency modulated signal with a longer time width.

[0023] In practice, the baseband data generation module generates linear frequency modulated (LFM) baseband data with a relatively large time width. Specifically, the baseband data generation module processes the LFM baseband signal... The real and imaginary parts are extracted to obtain the real part xI1(n) and the imaginary part xQ1(n) of the linear frequency modulated baseband signal x(n):

[0024] xI1(n)=real{x(n)}

[0025] xQ1(n)=imag{x(n)}

[0026] For the real part xI1(n) and the imaginary part xQ1(n), the baseband data generation module can perform a scaling transformation according to the following formula to obtain in-phase data xI2(n) and quadrature data xQ2(n).

[0027] xI2(n)=xI1(n)×(K-1)+K, xQ2(n)=xQ1(n)×(K-1)+K

[0028] Wherein, the data bit width of in-phase data xI2(n) and quadrature data xQ2(n) is L; where K is the scaling factor, K = 2L-1; j is the imaginary unit, ej[·] is the complex number representation; n is the time-domain point index value, n = 1, 2, ..., N; N is the length of the data sample, N = fs1·τ1, where fs1 is the clock frequency, τ1 is the pulse width of the linear frequency modulated signal with a large time width; μ is the frequency modulation slope, μ = B / τ1, where B is the frequency modulation bandwidth; 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.

[0029] In practice, the baseband data generation module sends the generated in-phase data xI2(n) and quadrature data xQ2(n) to the quadrature modulation module. The quadrature modulation module performs digital-to-analog conversion on the received in-phase data xI2(n) and quadrature data xQ2(n) respectively, with the conversion frequency equal to the clock frequency fs1, to form I and Q baseband analog signals yI1(t) and yQ1(t), where t is a time parameter. The quadrature modulation module performs low-pass filtering on the I and Q baseband analog signals yI1(t) and yQ1(t) respectively according to the following formula, to obtain the low-pass filtered I and Q baseband analog signals yI2(t) and yQ2(t):

[0030] yI2(t)=LPF{yI1(t)}, yQ2(t)=LPF{yQ1(t)},

[0031] Where LPF{·} represents the low-pass filtering operation, and the cutoff frequency of the low-pass filter is B / 2.

[0032] The quadrature modulation module processes the low-pass filtered I and Q baseband analog signals y I2 (t) and y Q2 (t) Perform quadrature modulation according to the following formula to synthesize a linear frequency modulated signal y1(t):

[0033] y1(t)=y I2 (t)cos(2πf0t)-y Q2 (t)sin(2πf0t)

[0034] Where f0 is the center frequency of the linear frequency modulated signal.

[0035] The quadrature modulation module performs bandpass filtering on the synthesized linear frequency modulated signal y1(t), resulting in y2(t) = BPF{y1(t)}, which gives y2(t) with a larger time width. Here, BPF{·} represents the bandpass filtering operation. When performing bandpass filtering, the quadrature modulation module can set the left relative decrease of 3dB sideband f1 = f0 - B / 2 and the right relative decrease of 3dB sideband f2 = f0 + B / 2. The bandpass filtering of y1(t) is then performed according to these 3dB relative decreases in the left and right sidebands f1 and f2.

[0036] In practice, the quadrature modulation module sends the generated linear frequency modulation signal y2(t) with a relatively large time width to the correction sequence generation module. The correction sequence generation module discretizes y2(t) to obtain discrete data p(n). The sampled sequence p(n) is subjected to discrete Hilbert transform: H(n) = hilbert[p(n)] to obtain the transform result H(n), where H(n) is a complex number, and hilbert[·] represents discrete Hilbert transform.

[0037] The correction sequence generation module processes H(n) according to the following conditions to obtain the processing results α1(n) and β1(n):

[0038] α1(n)=|H(n)|

[0039]

[0040] The correction sequence generation module then performs polynomial curve fitting on the processing results α1(n) and β1(n) respectively, with fitting orders of order q and r, to obtain curve 1 and curve 2. Then, curve 1 and curve 2 are sampled at equal intervals to obtain sequences α2(m) and β2(m).

[0041] Finally, the correction sequence generation module uses the formula... The amplitude correction sequence A(m) and the phase correction sequence can be obtained. Where m is the sampling point index, m = 1, 2, ..., M, and M is the data sample length, M = f s ·τ2; where τ2 is the pulse width of the linear frequency modulation signal with a small time width, τ2=τ1 / D, where D is a multiple, usually an integer between 200 and 300.

[0042] In summary, according to the embodiments of the present invention, a baseband data generation module can generate linear frequency modulation (LFM) baseband data with a large time width. An orthogonal modulation module performs digital-to-analog conversion on the baseband data and orthogonally modulates the conversion result to generate a LFM signal with a large time width. Then, a correction sequence generation module discretizes the LFM signal with a large time width and performs a discretization transformation to generate a broadband narrow pulse LFM signal correction sequence with a small deviation from the theoretical value of the correction sequence.

[0043] Based on the same technical concept, embodiments of the present invention provide a method for generating a broadband narrow-pulse linear frequency modulated signal correction sequence, such as... Figure 2 As shown, it includes:

[0044] S21, The baseband data generation module generates linear frequency modulation signal baseband data with a relatively large time width.

[0045] In practice, the baseband data generation module extracts the linear frequency modulated baseband signal. The real part x of the linear frequency modulated baseband signal is obtained by taking the real and imaginary parts of the signal. I1 (n) and imaginary part x Q1 (n);

[0046] The baseband data generation module calculates the real part x according to the following formula. I1 (n) and imaginary part x Q1(n) Perform scaling transformation to generate linear frequency modulated (LFM) signal baseband data with a longer time width, wherein the LFM signal baseband data with a longer time width includes: in-phase data and quadrature data.

[0047] x I2 (n)=x I1 (n)×(K-1)+K,x Q2 (n)=x Q1 (n)×(K-1)+K

[0048] Where, x I2 (n) represents in-phase data, x Q2 (n) represents orthogonal data, where the bit width of the in-phase and orthogonal data is L; K is the scaling rate, K = 2. L-1 j is the imaginary unit, e j[·] It is represented in complex number form; n is the time-domain point index value, n = 1, 2, ..., N; N is the length of the data sample, N = f s1 ·τ1,f s1 τ1 is the clock frequency, and μ is the pulse width of the linear frequency modulation signal with a large time width; μ is the frequency modulation slope, μ=B / τ1, and B is the frequency modulation bandwidth; 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.

[0049] S22. The quadrature modulation module performs digital-to-analog conversion on the baseband data, and performs quadrature modulation on the conversion result to generate a linear frequency modulation signal with a large time width.

[0050] In specific implementation, the quadrature modulation module performs digital-to-analog conversion on the in-phase data and quadrature data respectively to generate first and second baseband analog signals, wherein the conversion frequency is equal to the clock frequency, the first baseband analog signal is an I baseband analog signal, and the second baseband analog signal is a Q baseband analog signal.

[0051] The quadrature modulation module performs low-pass filtering on the first and second baseband analog signals respectively to generate a third and fourth baseband analog signal after low-pass filtering, wherein the cutoff frequency of the low-pass filtering is B / 2.

[0052] The quadrature modulation module performs quadrature modulation and bandpass filtering on the third baseband analog signal and the fourth baseband analog signal respectively to generate a linear frequency modulation signal with a large time width.

[0053] The quadrature modulation module performs quadrature modulation on the third baseband analog signal and the fourth baseband analog signal according to the following formula, and synthesizes a linear frequency modulated signal:

[0054] y1(t)=y I2 (t)cos(2πf0t)-y Q2(t)sin(2πf0t)

[0055] Where y1(t) is the synthesized linear frequency modulated signal, y I2 (t) represents the third baseband analog signal and y Q2 (t) is the fourth baseband analog signal, and f0 is the center frequency of the linear frequency modulated signal;

[0056] The synthesized linear frequency modulated (LFM) signal is subjected to bandpass filtering based on the 3dB relative decrease in the left and right sideband frequencies of the bandpass filter, thereby generating an LFM signal with a larger time width.

[0057] S23. The correction sequence generation module generates a correction sequence for the linear frequency modulation signal with a shorter time width based on the linear frequency modulation signal with a longer time width.

[0058] In practice, the correction sequence generation module discretizes the linear frequency modulated signal with a large time width to generate the first sampling sequence.

[0059] The correction sequence generation module performs a discrete Hilbert transform on the sampled sequence to generate a second sampled sequence;

[0060] The correction sequence generation module generates the third and fourth sample sequences according to the following formula:

[0061] α1(n)=|H(n)

[0062]

[0063] The correction sequence generation module performs curve fitting on the third and fourth sampling sequences to generate sampling curve 1 and sampling curve 2, respectively. It then performs equal-interval sampling on curve 1 and curve 2 to generate the fifth and sixth sampling sequences. The curve fitting orders are q and r, respectively.

[0064] The correction sequence generation module generates a correction sequence for a linear frequency modulated signal with a short time width according to the following formula. The correction sequence includes an amplitude correction sequence and a phase correction sequence:

[0065]

[0066]

[0067] Where A(m) is the amplitude correction sequence, α2(m) is the fifth sampling sequence, φ(m) is the phase correction sequence, and β2(m) is the sixth sampling sequence.

[0068] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A broadband narrow-pulse linear frequency modulated signal correction sequence generation device, characterized in that, include: The system includes a baseband data generation module, a quadrature modulation module, and a correction sequence generation module, wherein the baseband data generation module is connected to the quadrature modulation module, and the quadrature modulation module is connected to the correction sequence generation module. The baseband data generation module is used to generate linear frequency modulation signal baseband data with a relatively long time width. The quadrature modulation module is used to perform digital-to-analog conversion on baseband data, and to perform quadrature modulation on the conversion result to generate a linear frequency modulation signal with a large time width. The correction sequence generation module is used to generate a correction sequence for a linear frequency modulation signal with a shorter time width based on the linear frequency modulation signal with a longer time width. The baseband data generation module is specifically used for: Extracting linear frequency modulated baseband signal The real part of the linear frequency modulated baseband signal is obtained by taking the real and imaginary parts of the signal. x I1 ( n ) and imaginary part x Q1 ( n ); The real part is determined according to the following formula. x I1 ( n ) and imaginary part x Q1 ( n The scaling transformation is performed to generate linear frequency modulated (LFM) signal baseband data with a longer time width. This LFM signal baseband data includes in-phase data and quadrature data. x I 2 ( n )= x I1 ( n )×( K -1)+ K ， x Q2 ( n )= x Q1 ( n )×( K -1)+ K in, x I2 ( n () represents in-phase data. x Q2 ( n The data is orthogonal, and the bit width of the in-phase data and the orthogonal data is... L ; K For scaling rate, K =2 L-1 ; j The imaginary unit, e j[·] It is in complex form; n For time-domain point index values, n =1,2,…, N ; N The length of the data sample. N = f s1 · τ 1, f s1 For clock frequency, τ 1 represents the pulse width of a linear frequency modulation signal with a relatively large time width; µ For frequency modulation slope, µ = B / τ 1, B The frequency modulation bandwidth; real{·} represents the operation of taking the real part of a complex number, and imag{·} represents the operation of taking the imaginary part of a complex number; The quadrature modulation module is specifically used for: The in-phase data and quadrature data are respectively converted from digital to analog to generate first and second baseband analog signals, wherein the conversion frequency is equal to the clock frequency, the first baseband analog signal is an I baseband analog signal, and the second baseband analog signal is a Q baseband analog signal; The first and second baseband analog signals are respectively subjected to low-pass filtering to generate a third and fourth baseband analog signal after low-pass filtering, wherein the cutoff frequency of the low-pass filtering is . ,in, For frequency modulation bandwidth; The third baseband analog signal and the fourth baseband analog signal are respectively subjected to quadrature modulation and bandpass filtering to generate a linear frequency modulation signal with a large time width. The correction sequence generation module is specifically used for: The linear frequency modulated signal with a large time width is discretized to obtain discrete data, and the discrete Hilbert transform is performed on the discrete data to obtain the transform result; The transformation results are processed according to the following formulas to obtain the processing results. and : in, Indicates the result of the transformation; The processing results were analyzed separately. and Perform polynomial curve fitting, with fitting orders of respectively q order and r By dividing the order, we obtain curve 1 and curve 2; The curves 1 and 2 are sampled at equal intervals to obtain the sequence. and ; According to the formula , Obtain the amplitude correction sequence A ( m and phase correction sequence φ ( m ), where m is the sampling point index, , For the length of the data sample, ;in, τ 2 represents the pulse width of a linear frequency modulated signal with a short time width. τ 2= τ 1 / D , D It is a multiple.

2. The apparatus according to claim 1, characterized in that, The process of performing quadrature modulation and bandpass filtering on the third and fourth baseband analog signals to generate a linear frequency modulated signal with a large time width specifically includes: The third baseband analog signal and the fourth baseband analog signal are orthogonally modulated according to the following formula to synthesize a linear frequency modulated signal: in, The synthesized linear frequency modulated signal, For the third baseband analog signal and This is the fourth baseband analog signal. The center frequency of the linear frequency modulated signal; The synthesized linear frequency modulated (LFM) signal is subjected to bandpass filtering based on the 3dB relative decrease in the left and right sideband frequencies of the bandpass filter, thereby generating an LFM signal with a larger time width.

3. A method for generating a broadband narrow-pulse linear frequency modulated signal correction sequence, characterized in that, include: The baseband data generation module generates linear frequency modulated signal baseband data with a relatively large time width. The quadrature modulation module performs digital-to-analog conversion on the baseband data, and performs quadrature modulation on the conversion result to generate a linear frequency modulation signal with a large time width; The correction sequence generation module generates a correction sequence for the linear frequency modulated signal with a shorter time width based on the linear frequency modulated signal with a longer time width. The baseband data generation module generates linear frequency modulated signal baseband data with a relatively large time width, specifically including: The baseband data generation module extracts the linear frequency modulated baseband signal. The real part of the linear frequency modulated baseband signal is obtained by taking the real and imaginary parts of the signal. x I1 ( n ) and imaginary part x Q1 ( n ); The real part is determined according to the following formula. x I1 ( n ) and imaginary part x Q1 ( n The scaling transformation is performed to generate linear frequency modulated (LFM) signal baseband data with a longer time width. This LFM signal baseband data includes in-phase data and quadrature data. x I 2 ( n )= x I1 ( n )×( K -1)+ K ， x Q2 ( n )= x Q1 ( n )×( K -1)+ K in, x I2 ( n () represents in-phase data. x Q2 ( n The data is orthogonal, and the bit width of the in-phase data and the orthogonal data is... L ; K For scaling rate, K =2 L-1 ; j The imaginary unit, e j[·] It is in complex form; n For time-domain point index values, n =1,2,…, N ; N The length of the data sample. N = f s1 · τ 1, f s1 For clock frequency, τ 1 represents the pulse width of a linear frequency modulation signal with a relatively large time width; µ For frequency modulation slope, µ = B / τ 1, B The frequency modulation bandwidth; real{·} represents the operation of taking the real part of a complex number, and imag{·} represents the operation of taking the imaginary part of a complex number; The quadrature modulation module performs digital-to-analog conversion on the baseband data, and performs quadrature modulation on the conversion result to generate a linear frequency modulated signal with a large time width, specifically including: The quadrature modulation module performs digital-to-analog conversion on the in-phase data and quadrature data respectively to generate first and second baseband analog signals, wherein the conversion frequency is equal to the clock frequency, the first baseband analog signal is an I baseband analog signal, and the second baseband analog signal is a Q baseband analog signal; The first and second baseband analog signals are respectively subjected to low-pass filtering to generate a third and fourth baseband analog signal after low-pass filtering, wherein the cutoff frequency of the low-pass filtering is . ; The third baseband analog signal and the fourth baseband analog signal are respectively subjected to quadrature modulation and bandpass filtering to generate a linear frequency modulation signal with a large time width. The correction sequence generation module generates a correction sequence for the linear frequency modulated signal with a shorter time width based on the linear frequency modulated signal with a longer time width, including: The linear frequency modulated signal with a large time width is discretized to obtain discrete data, and the discrete Hilbert transform is performed on the discrete data to obtain the transform result; The transformation results are processed according to the following formulas to obtain the processing results. and : in, Indicates the result of the transformation; The processing results were analyzed separately. and Perform polynomial curve fitting, with fitting orders of respectively q order and r By dividing the order, we obtain curve 1 and curve 2; The curves 1 and 2 are sampled at equal intervals to obtain the sequence. and ; According to the formula , Obtain the amplitude correction sequence A ( m and phase correction sequence φ ( m ), where m is the sampling point index, , For the length of the data sample, ;in, τ 2 represents the pulse width of a linear frequency modulated signal with a short time width. τ 2= τ 1 / D , D It is a multiple.

4. The method according to claim 3, characterized in that, The process of performing quadrature modulation and bandpass filtering on the third and fourth baseband analog signals to generate a linear frequency modulated signal with a large time width specifically includes: The third baseband analog signal and the fourth baseband analog signal are orthogonally modulated according to the following formula to synthesize a linear frequency modulated signal: in, The synthesized linear frequency modulated signal, For the third baseband analog signal and This is the fourth baseband analog signal. The center frequency of the linear frequency modulated signal; The synthesized linear frequency modulated (LFM) signal is subjected to bandpass filtering based on the 3dB relative decrease in the left and right sideband frequencies of the bandpass filter, thereby generating an LFM signal with a larger time width.

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