CN-122017740-A - Dual-mode millimeter wave radar channel amplitude-phase distortion compensation method, device and storage medium

Abstract

The invention discloses a method, a device and a storage medium for compensating amplitude-phase distortion of a dual-mode millimeter wave radar channel, which comprise the steps of obtaining a receiving and transmitting control parameter and analyzing the receiving and transmitting control parameter to obtain a transmitting waveform parameter and a local oscillation waveform parameter, starting from a low-frequency end of a system working bandwidth, adjusting the transmitting waveform parameter and the local oscillation waveform parameter to generate a pair of single-tone correction signals which are respectively used as a transmitting pre-driving signal and a local oscillation pre-driving signal, generating an analog intermediate frequency signal according to the transmitting pre-driving signal and the local oscillation pre-driving signal, extracting a distortion amplitude-phase value corresponding to a current frequency point from the analog intermediate frequency signal, controlling the frequency of the pair of single-tone correction signals to gradually increase according to a preset step length to obtain distortion amplitude-phase values of a plurality of frequency points, carrying out interpolation fitting on the distortion amplitude-phase values, calculating equalizer coefficients, adjusting step frequencies and repeatedly calculating until all equalizer coefficients are obtained for compensating the amplitude-phase distortion of the dual-mode radar channel.

Inventors

• WU BING
• Gan Luxia
• WANG ZHIPENG
• DUAN ZONGMING
• ZHANG QUN
• WANG RUIYANG

Assignees

• 安徽大学

Dates

Publication Date

20260512

Application Date

20260129

Claims (20)

1. 1. A method for compensating amplitude-phase distortion of a dual-mode millimeter wave radar channel is characterized by comprising the following steps: S1, acquiring a receiving and transmitting control parameter and analyzing the receiving and transmitting control parameter to obtain a transmitting waveform parameter and a local oscillator waveform parameter; S2, starting from a low-frequency end of a system working bandwidth, adjusting a transmitting waveform parameter and a local oscillator waveform parameter, generating a pair of single-tone correction signals and respectively serving as a transmitting pre-driving signal and a local oscillator pre-driving signal; S3, generating an analog intermediate frequency signal according to the transmitting pre-driving signal and the local oscillator pre-driving signal, and extracting a distortion amplitude-phase value corresponding to the current frequency point from the analog intermediate frequency signal; S4, controlling the frequency of the paired tone correction signals to gradually increase according to a preset step frequency step length, and repeatedly executing the steps S2-S3 until the frequency reaches a high-frequency end of a system working bandwidth, and obtaining distortion amplitude and phase values corresponding to a plurality of frequency points in the system working bandwidth; s5, carrying out interpolation fitting on the distortion amplitude and phase values of the plurality of frequency points in a sampling frequency range, and calculating an equalizer coefficient of the current stepping frequency step; And S6, adjusting a preset step frequency step length, and repeatedly executing the steps S2-S5 until equalizer coefficients corresponding to all typical step frequency step lengths are obtained so as to be used for compensating the amplitude-phase distortion of the dual-mode millimeter wave radar channel.
2. 2. The method for compensating amplitude-phase distortion of a dual-mode millimeter wave radar channel according to claim 1, wherein the steps of obtaining the transmit-receive control parameter and analyzing the transmit-receive control parameter to obtain the transmit waveform parameter and the local oscillator waveform parameter, further comprise: Analyzing the receiving and transmitting control parameters to obtain serial frames in the receiving and transmitting control parameters, and sequentially extracting a transmitting waveform parameter, a local oscillator waveform parameter and a closed loop correction selection signal; The closed loop correction selection signal is used for controlling the switching of the signal flow paths in the correction state and the normal working state.
3. 3. The method for compensating amplitude-phase distortion of a dual-mode millimeter wave radar channel according to claim 1, wherein the steps of starting from a low frequency end of a system operating bandwidth, adjusting a transmit waveform parameter and a local oscillator waveform parameter, generating a pair of tone correction signals as a transmit pre-drive signal and a local oscillator pre-drive signal, respectively, comprise: mapping the transmitting waveform parameter and the local oscillator waveform parameter into a transmitting waveform frequency parameter and a local oscillator waveform frequency parameter respectively; In the range of the system working bandwidth, taking a low-frequency end as the initial frequency of the working bandwidth, respectively carrying out frequency stepping on the frequency parameter of the transmitting waveform and the frequency parameter of the local oscillator waveform according to a set stepping step length until the total stepping times are reached, and calculating the frequency of the transmitting waveform and the frequency of the local oscillator waveform corresponding to each frequency stepping; generating a corresponding transmitting digital signal according to the transmitting waveform frequency corresponding to each frequency step, and generating a corresponding digital local oscillation signal according to the local oscillation waveform parameter corresponding to each frequency step; carrying out delay processing on the transmitting digital signal corresponding to each frequency step to generate a transmitting digital delay signal, mapping the transmitting digital delay signal to a continuous time domain, and then carrying out frequency mixing processing on the transmitting digital delay signal and a fixed frequency to obtain the transmitting pre-driving signal; And carrying out equalization processing on the digital local oscillation signals corresponding to each frequency step to obtain equalized local oscillation digital signals, mapping the equalized local oscillation digital signals to a continuous time domain, and then carrying out frequency mixing with fixed frequency to obtain the local oscillation pre-driving signals.
4. 4. The method for compensating amplitude-phase distortion of a dual-mode millimeter wave radar channel according to claim 3, wherein said delaying the transmitted digital signal corresponding to each frequency step to generate a transmitted digital delayed signal, mapping the transmitted digital delayed signal to a continuous time domain, and mixing with a fixed frequency to obtain the transmitted pre-driving signal, comprises: Carrying out channel digital path delay processing on the transmitting digital signal corresponding to each frequency step to generate a transmitting digital delay signal, wherein the formula is as follows: In the formula, In order to transmit the digital delay signal, In order to transmit the digital signal, Is the base of the natural logarithm, In imaginary units, the channel digital path delays , For the number of taps of the FIR equalization filter, Is the first The secondary frequency steps the corresponding transmit waveform frequency, For the sampling frequency to be the same, The number of sampling points for transmitting the digital signal; performing digital-to-analog conversion on the emission digital delay signal to map the emission digital delay signal to a continuous time domain, and then performing mixing processing on the emission digital delay signal and the fixed frequency to obtain the emission pre-driving signal, wherein the formula is as follows: In the formula, In order to transmit the pre-drive signal, In order to transmit the pre-drive signal amplitude, Is the base of the natural logarithm, In imaginary units, the channel digital path delays , For the number of taps of the FIR equalization filter, Is the first The secondary frequency steps the corresponding transmit waveform frequency, For a fixed frequency of the mixing, Is a time scale.
5. 5. The method for compensating amplitude-phase distortion of a dual mode millimeter wave radar channel according to claim 3, wherein said equalizing the digital local oscillator signal corresponding to each frequency step to obtain an equalized local oscillator digital signal, mapping the equalized local oscillator digital signal to a continuous time domain, and mixing with a fixed frequency to obtain the local oscillator pre-drive signal, comprises: Carrying out equalization processing on the digital local oscillation signals corresponding to each frequency step to obtain equalized local oscillation digital signals, wherein the formula is expressed as follows: In the formula, For the equalized local oscillator digital signal, As a digital local oscillator signal, To pre-correct the transfer function of the single-bit equalizer, In the form of discrete convolutions of symbols, For the number of taps of the FIR equalization filter, For the FIR equalization filter tap coefficients, Is the original local oscillation digital signal, <1 Time Taking a zero value; 1 time The value of the local oscillator digital signal is normally taken, ; Performing digital-to-analog conversion on the balanced local oscillator digital signal, mapping the digital-to-analog conversion to a continuous time domain, and performing mixing processing on the digital-to-analog conversion and the fixed frequency to obtain the local oscillator pre-driving signal, wherein the formula is expressed as follows: In the formula, Is a local oscillation pre-drive signal, Is the amplitude of the local oscillator pre-drive signal, Is the base of the natural logarithm, In units of imaginary numbers, Is the first The secondary frequency steps the corresponding local oscillator waveform frequency, For the sampling frequency to be the same, For a fixed frequency of the mixing, Is a time scale.
6. 6. The method for compensating for channel amplitude-phase distortion of dual mode millimeter wave radar of claim 5, wherein said transfer function At the position of The expression of the domain is: In the formula, And the unit balance is satisfied.
7. 7. A dual mode millimeter wave radar channel amplitude and phase distortion compensation method as recited in claim 1 or 3, wherein the transmit pre-drive signal and the local oscillator pre-drive signal are a pair of single tone signals having a fixed frequency difference, said fixed frequency difference being equal to a predetermined step frequency step size.
8. 8. The method for compensating amplitude-phase distortion of a dual-mode millimeter wave radar channel according to claim 2, wherein the generating an analog intermediate frequency signal according to the transmission pre-drive signal and the local oscillator pre-drive signal, and extracting a distorted amplitude-phase value corresponding to a current frequency point from the analog intermediate frequency signal, comprises: After filtering and power amplifying the transmission pre-driving signal, coupling part of signals in the amplified radio frequency transmission signals to serve as coupling detection signals, and sending the other part of signals to a transmission antenna as transmission signals; after filtering and power amplification are carried out on the local oscillator pre-driving signal, a radio frequency receiving local oscillator signal is generated, wherein the delay time of a digital transmission path corresponding to the transmitting pre-driving signal and the local oscillator pre-driving signal is the same; Based on the closed loop correction selection signal, the coupling detection signal is used as a receiving selection signal to be sequentially subjected to frequency mixing, filtering and amplifying treatment with the radio frequency receiving local oscillation signal, and an analog intermediate frequency signal is generated; And extracting a distortion amplitude-phase value corresponding to the current frequency point after analog-to-digital conversion processing is carried out on the analog intermediate frequency signal.
9. 9. The method for compensating amplitude-phase distortion of a dual-mode millimeter wave radar channel according to claim 8, wherein the extracting the distortion amplitude-phase value corresponding to the current frequency point after the analog intermediate frequency signal is subjected to analog-to-digital conversion processing comprises: performing analog-to-digital conversion on the analog intermediate frequency signal to obtain compensation echo data, and extracting multi-frequency point correction data of the compensation echo signal within the range of a working bandwidth, wherein a single-point frequency data formula is expressed as follows: In the formula, As a single-point frequency signal, For the amplitude value of the signal after mixing, In order to obtain the phase difference after mixing, For the frequency difference to be the same, In order to be a phase of the light, Is the base of the natural logarithm, In units of imaginary numbers, The sequence number is the sequence number of the time domain sampling point; And performing DFT conversion on the multi-frequency point correction data, and extracting amplitude and phase values corresponding to the transmitting frequency and the local oscillation frequency to serve as distortion amplitude and phase values corresponding to the current frequency point.
10. 10. The method for compensating amplitude-phase distortion of a dual-mode millimeter wave radar channel according to claim 1, wherein the interpolating fitting is performed on the distorted amplitude-phase values of the plurality of frequency points in a sampling frequency range, and the equalizer coefficient of the current step frequency step is calculated, comprising: Performing interpolation fitting on the distorted amplitude and phase values of a plurality of frequency points in a sampling frequency range, and performing inverse response calculation on amplitude and phase interpolation data, wherein frequency coordinates of the interpolation frequency points correspond to frequency points of fast Fourier transform for calculating equalizer coefficients one by one; Constructing a DFT matrix of the inverse response of the amplitude-phase interpolation data according to the inverse response of the amplitude-phase interpolation data; according to the system working bandwidth, the sampling frequency and the FFT point number after frequency domain interpolation, constructing a weighting vector of inverse response of amplitude-phase interpolation data; Based on the DFT matrix and the weighting vector of the amplitude-phase interpolation inverse response, the equalizer coefficient of the current stepping frequency step length is solved by using a weighted least square method.
11. 11. The method for compensating amplitude-phase distortion of a dual-mode millimeter wave radar channel according to claim 10, wherein performing interpolation fitting on the distorted amplitude-phase values of the plurality of frequency points in a sampling frequency range and performing inverse response calculation on the amplitude-phase interpolation data comprises: performing interpolation fitting on the distorted amplitude and phase values of a plurality of frequency points in a sampling frequency range, and designing the frequency response of the equalizer as the inverse response of amplitude and phase interpolation data: In the formula, For the inverse response after interpolation of the amplitude-phase distortion, For the number of FFT frequency points after frequency domain interpolation, For the amplitude distortion value corresponding to the kth FFT bin, The phase distortion value corresponding to the kth FFT frequency point is obtained; and performing delay compensation on the inverse response of the amplitude-phase interpolation data to obtain a frequency domain response vector, wherein the formula is as follows: In the formula, Is a frequency domain response vector that, For the inverse response after interpolation of the amplitude-phase distortion, Representing the multiplication by element, The phase vector is compensated for the time delay, , The number of points for the introduced delay.
12. 12. The method for compensating for amplitude-phase distortion of a dual mode millimeter wave radar channel according to claim 10, wherein the constructing a DFT matrix of the amplitude-phase interpolation data inverse response according to the amplitude-phase interpolation data inverse response is expressed as: In the formula, In the case of a DFT matrix, For the number of taps of the FIR equalization filter, For the number of FFT frequency points after frequency domain interpolation, For the FFT bin sequence number, For the FIR equalization filter tap sequence number.
13. 13. The method for compensating for channel amplitude-phase distortion of a dual mode millimeter wave radar of claim 10, wherein the weighting vector is calculated using an amplitude weighting scheme, wherein the equalizer compensates for the frequency response with an in-band weighting amplitude higher than that of the out-of-band.
14. 14. The method for compensating amplitude-phase distortion of dual-mode millimeter wave radar channel according to claim 10, wherein said constructing a weighting vector of inverse response of amplitude-phase interpolation data according to system operating bandwidth, sampling frequency and FFT point number after frequency domain interpolation comprises: Constructing a frequency domain weighting vector according to the system working bandwidth, the sampling frequency and the FFT point number after frequency domain interpolation, wherein the frequency domain weighting vector is: In the formula, For the frequency domain weight vector, For the number of FFT points after frequency domain interpolation, For the operating bandwidth of the system, Is the sampling frequency; Calculating a normalized weighting matrix based on the frequency domain weighting vector as: In the formula, In order to normalize the weighting matrix, The representation constructs a diagonal matrix in vector elements.
15. 15. The method for compensating for amplitude-phase distortion of a dual mode millimeter wave radar channel according to claim 10, wherein said solving equalizer coefficients of a current step frequency step by using a weighted least square method based on a DFT matrix and a weight vector of an amplitude-phase interpolation inverse response comprises: the method comprises the steps of constructing a weighted least square coefficient solution problem based on a DFT matrix and a weighted vector of amplitude-phase interpolation inverse response, wherein the solution problem comprises the following steps: In the formula, For the time domain FIR equalization filter coefficient vector, In order to normalize the weighting matrix, In the case of a DFT matrix, Is a frequency domain response vector that, To find the optimum A value to minimize the weighted sum of squares error; solving the weighted least square coefficient solving problem, and calculating the weighted least square solution As the equalizer coefficients for the current step frequency step, For the number of taps of the FIR equalization filter, Tap coefficient values for the FIR equalization filter.
16. 16. The method for compensating for the amplitude-phase distortion of a dual mode millimeter wave radar channel according to claim 2, wherein the process of compensating for the amplitude-phase distortion of the dual mode millimeter wave radar channel comprises: when switching to a normal working state based on the closed loop correction selection signal, determining a working mode of the dual-mode millimeter wave radar receiving and transmitting system; When in the step frequency working mode, selecting equalizer coefficients corresponding to the current step frequency interval from an equalizer coefficient table to realize amplitude-phase distortion compensation of a step frequency channel; estimating the intermediate frequency based on prior information when the linear frequency modulation working mode is in the linear frequency modulation working mode, and selecting an equalizer coefficient with the step length closest to the estimated intermediate frequency from an equalizer coefficient table to realize amplitude-phase distortion compensation of the linear frequency modulation channel; The equalizer coefficient table is constructed based on equalizer coefficients corresponding to all typical step frequency steps.
17. 17. The method for compensating for amplitude-phase distortion of a dual mode millimeter wave radar channel according to claim 16, wherein said estimating the intermediate frequency based on a priori information while in the chirped mode of operation comprises: Estimating a time parameter of the received signal based on known distance or time interval information between the transmitted signals; Establishing a mapping relation by utilizing the linear corresponding relation between the time parameter and the frequency; substituting the time parameter into the mapping relation, and calculating to obtain a corresponding intermediate frequency deviation or intermediate frequency value.
18. 18. The device for compensating the amplitude-phase distortion of the dual-mode millimeter wave radar channel is characterized by comprising the following components: The correction processor is used for acquiring the receiving and transmitting control parameters, analyzing the receiving and transmitting control parameters, obtaining the transmitting waveform parameters and the local oscillation waveform parameters, and respectively transmitting the transmitting waveform parameters and the local oscillation waveform parameters to the transmitting waveform generator and the local oscillation waveform generator; the transmitting waveform generator is used for adjusting transmitting waveform parameters from a low-frequency end of the system working bandwidth, generating a transmitting pre-driving signal and sending the transmitting pre-driving signal to the transmitting assembly; The local oscillation waveform generator is used for adjusting local oscillation waveform parameters from a low-frequency end of the system working bandwidth, generating a local oscillation pre-driving signal and sending the local oscillation pre-driving signal to the receiving assembly; The transmitting component is used for converting the transmitting pre-driving signal and then transmitting the converted transmitting pre-driving signal to the receiving component so that the receiving component generates an analog intermediate frequency signal based on the converted transmitting pre-driving signal and the received local oscillator pre-driving signal and transmits the analog intermediate frequency signal to the correction processor; The correction processor is also used for extracting a distortion amplitude-phase value corresponding to a current frequency point from the analog intermediate frequency signal, controlling the frequency of the transmission pre-driving signal generated by the transmission waveform generator and the frequency of the local oscillator pre-driving signal generated by the local oscillator waveform generator to gradually increase according to a preset step frequency step length until the frequency reaches a high frequency end of the system working bandwidth to obtain distortion amplitude-phase values corresponding to a plurality of frequency points in the system working bandwidth, carrying out interpolation fitting on the distortion amplitude-phase values of the plurality of frequency points in a sampling frequency range, calculating to obtain equalizer coefficients of the current step frequency step length, adjusting the preset step frequency step length, controlling the transmission waveform generator to regenerate the transmission pre-driving signal, and controlling the local oscillator pre-driving signal regenerated by the local oscillator waveform generator until the equalizer coefficients corresponding to all typical step frequency step lengths are obtained for carrying out millimeter wave radar channel amplitude-phase distortion compensation.
19. 19. The dual mode millimeter wave radar channel amplitude and phase distortion compensation device of claim 18, wherein said correction processor is coupled to a signal processor, said signal processor being configured to configure said transmit receive control parameters; the transceiver control parameters include a working mode parameter, a transmitting link parameter and a receiving link parameter.
20. 20. The dual mode millimeter wave radar channel amplitude and phase distortion compensation device of claim 18, wherein said correction processor comprises: and the receiving and transmitting parameter analysis unit is used for analyzing the received receiving and transmitting control parameters to obtain serial frames in the receiving and transmitting control parameters, sequentially extracting the transmitting waveform parameters, the local oscillation waveform parameters and the closed-loop correction selection signals, and transmitting the closed-loop correction selection signals to the receiving component.

Description

Dual-mode millimeter wave radar channel amplitude-phase distortion compensation method, device and storage medium Technical Field The invention relates to the technical field of radar signal processing, in particular to a method and a device for compensating amplitude-phase distortion of a dual-mode millimeter wave radar channel and a storage medium. Background Along with the wide application of millimeter wave radar in fields of automobile electronics, intelligent perception and the like, the requirements of a system on channel consistency and signal fidelity are increasingly improved. Dual mode radars, such as step-frequency and chirp mixed mode, are favored for their ability to have both high resolution and flexible waveform configuration. However, in the multichannel receiving system, factors such as device process deviation, temperature drift, and nonlinear frequency response may cause inconsistent amplitude and phase among channels, thereby affecting radar imaging quality and target detection accuracy. The channel equalization technology commonly used in the broadband phased array radar at present mainly comprises two types of analog equalization and digital equalization. The analog equalization method is usually implemented by a wideband analog filter, but increases the system volume and complexity, and makes flexible adaptation of multichannel tuning difficult. The digital equalization method is realized based on a digital filter or a frequency domain compensation algorithm, and has better flexibility, but has higher requirements on high-speed sampling and real-time processing resources, and particularly faces the challenges of cost and synchronous control in a large-scale array. Because the two compensation methods based on fixed parameters, namely analog equalization and digital equalization, usually estimate and compensate channel amplitude phase response under a single working mode and specific working conditions, the compensation parameters thereof remain unchanged during the running process of the system. However, in a dual-mode radar system, there are significant differences in the signal spectrum structure, excitation mode and effective channel model corresponding to different step frequency modes and chirp modes, resulting in dynamic changes in channel amplitude-phase distortion characteristics with the working mode. The fixed parameter compensation method is difficult to simultaneously adapt to different modulation modes and dynamic switching processes thereof, so that the compensation effect is obviously reduced in a dual-mode dynamic switching scene, and the requirements of high-precision imaging and target detection are difficult to meet. Especially under the broadband working condition, the amplitude-frequency and phase-frequency response distortion of the channel can be further deteriorated, and the traditional compensation method based on fixed parameters is difficult to adapt to the working scene of dual-mode dynamic switching. In recent years, attention has been paid to a channel nonlinear correction method under a deskewing architecture, such as a multichannel time-varying correction factor scheme proposed by Zhang Peng et al in a broadband channel digital equalization method based on deskewing, which can alleviate the problem of channel nonlinear inconsistency to a certain extent and perform deskewing post-compensation based on a linear frequency modulation signal. However, the method is essentially only suitable for linear frequency modulation waveforms, because the channel nonlinear correction method under the declassification processing architecture uses the linear frequency modulation signal as excitation, and relies on a stable single difference frequency structure and continuous linear phase evolution characteristics formed after declassification processing, so that difference frequency extraction, reference signal construction and time-varying correction factor modeling are realized. However, the step frequency waveform is essentially a discrete frequency point and a segmented constant frequency signal, and does not have continuous sweep frequency characteristics, so that the amplitude-phase distortion information of different frequency points cannot be extracted in the time domain in single measurement, and key steps related to difference frequency extraction, linear phase modeling and time-varying nonlinear compensation are not established in a step frequency mode, so that the channel nonlinear correction method of the declining architecture is difficult to be directly applied to channel correction of the step frequency waveform. The declassification processing architecture needs to change and store different time-varying correction factors for different distorted waveforms, cannot be directly expanded to other waveform systems such as step frequency and the like, and does not relate to the problem of coefficient adaptation under the dual-mode dynamic switching condition