Signal processing method, storage medium, integrated circuit, device and terminal equipment

Abstract

The embodiment of the invention relates to the technical field of signal processing, and discloses a signal processing method, a storage medium, an integrated circuit, a device and terminal equipment, and the method is applied to nonlinear compensation after sampling an intermediate frequency signal obtained based on an echo signal. Eliminating a nonlinear factor of a transmitting signal part in the echo signal; anti-skew filtering is carried out on the echo signal after the non-linear factor of the emission signal part is eliminated, a filtered echo signal is obtained, and residual phase errors in the filtered echo signal are aligned in time; and compensating a residual phase error in the filtered echo signal to obtain a non-linearly compensated echo signal. According to the signal processing method provided by the embodiment of the invention, the linearity of frequency sweeping of the radar system can be effectively improved, the cost is reduced, and the radar system with a relatively wide interested distance interval also has good performance.

Description

Technical Field

[0001] The embodiments of the present application relate to the technical field of signal processing, and in particular, to a signal processing method, a storage medium, an integrated circuit, a device, and a terminal device. Background Art

[0002] A radar is a device that uses electromagnetic wave signals to detect targets. It has a wide range of applications in the field of target detection. With the development of radar technology, the cost of radar has become lower and lower, and its volume has become smaller and smaller. Radar has gradually become an indispensable technology in human daily production and life. Radar can use the frequency difference (beat frequency) between the transmitted signal and the signal returned from the target (reflected signal, also called received signal, echo signal), that is, obtain an intermediate frequency signal (IF, Intermediate Frequency) according to the transmitted signal and the received signal, to calculate the distance to the target.

[0003] Since the frequency changes rapidly over time, the performance of the radar depends to a large extent on the linearity of the transmitted signal. If the instantaneous frequency of the radar chirp deviates from linearity, or its phase deviates from a quadratic function, it will cause multiple components to appear in the frequency of the intermediate frequency signal, which will in turn lead to the appearance of false side lobes and / or false targets, the decrease of the signal-to-noise ratio, and the decrease of the resolution and accuracy of the radar detection distance. Summary of the Invention

[0004] The purpose of the embodiments of the present application is to provide a signal processing method, a storage medium, an integrated circuit, a device, and a terminal device, which effectively improve the linearity of the frequency sweep of the radar system, not only reduce the cost, but also have good performance in radar systems with a relatively wide range of distances of interest.

[0005] To solve the above technical problems, an embodiment of the present application provides a signal processing method, which can be applied to non-linear compensation of the sampled signal of the intermediate frequency signal obtained based on the echo signal. The method may include the following steps: using a preset phase error function to eliminate the non-linear factor of the transmitted signal part in the echo signal; performing anti-skew filtering on the echo signal after eliminating the non-linear factor of the transmitted signal part to obtain a filtered echo signal, and the residual phase error in the filtered echo signal is aligned in time; compensating the residual phase error in the filtered echo signal to obtain a non-linearly compensated echo signal.

[0006] An embodiment of the present application also provides a computer-readable storage medium, storing a computer program, and when the computer program is executed by a processor, the signal processing method in the embodiments of the present application can be implemented.

[0007] Embodiments of the present application further provide an integrated circuit, which may include: a signal transceiver channel, which can be used to transmit radio signals and receive echo signals formed by reflection of the radio signals by a target; a signal processing module, which can be used to perform non-linear compensation on the sampled signals of the intermediate frequency signals obtained based on the echo signals according to the signal processing method as described above. The signal processing module may include: a first compensation unit, which is used to eliminate the non-linear factor of the transmitted signal part in the echo signal by using a preset phase error function; an anti-skew filtering unit, which is used to perform anti-skew filtering on the echo signal after eliminating the non-linear factor of the transmitted signal part to obtain a filtered echo signal, and the residual phase errors in the filtered echo signal are aligned in time; a second compensation unit, which is used to compensate the residual phase errors in the filtered echo signal to obtain a non-linearly compensated echo signal.

[0008] It should be noted that, for the first compensation unit, the anti-skew filtering unit and the second compensation unit, they can be partially or fully shared to improve the integration level, or the hardware structures can be separately set according to requirements to improve the overall signal processing efficiency.

[0009] Embodiments of the present application further provide a radio device, including: a carrier; the integrated circuit as described above, which is arranged on the carrier; an antenna, which is arranged on the carrier and is used to transmit and receive radio signals.

[0010] Embodiments of the present application further provide a terminal device, including: a device body; and the radio device as described above, which is arranged on the device body, and the radio device is used for target detection and / or communication.

[0011] For the signal processing method, storage medium, integrated circuit, device and terminal device provided by the embodiments of the present application, when performing non-linear compensation after sampling the intermediate frequency signals obtained based on the echo signals, first use a preset phase error function to eliminate the non-linear factor of the transmitted signal part in the echo signal, then perform anti-skew filtering on the echo signal after eliminating the non-linear factor of the transmitted signal part to obtain a filtered echo signal, and the residual phase errors in the filtered echo signal are aligned in time, and finally compensate the residual phase errors in the filtered echo signal to obtain a non-linearly compensated echo signal. Considering that the general hardware non-linear compensation method in the industry is easily affected by changes in the external environment and the transmission bandwidth is also very limited, and the general software non-linear compensation method in the industry has a limited applicable distance range and cannot perform linear compensation on a radar system with a relatively wide distance range of interest, therefore, in the embodiments of the present application, the non-linear factor in the echo signal is regarded as a quantity that changes with distance, and non-linear compensation is performed on the transmitting side and the receiving side in sequence, effectively improving the linearity of the frequency sweep of the radar system, not only reducing the cost, but also having good performance in a radar system with a relatively wide distance range of interest.

[0012] In some alternative embodiments, eliminating the non - linear factor of the transmitted - signal part in the echo signal by using a preset phase - error function includes: mixing the echo signal with a local - oscillator signal to obtain an intermediate - frequency signal corresponding to the echo signal; multiplying the intermediate - frequency signal by the preset phase - error function to obtain a signal after the first processing, and the signal after the first processing is a signal with the non - linear factor of the transmitted - signal part eliminated. In the intermediate - frequency signal formed after the echo signal is mixed with the local - oscillator signal, there are the non - linear factor of the transmitted - signal part and the non - linear factor of the received - signal part, which is manifested as a phase change in the signal. Multiplying the intermediate - frequency signal by the preset phase - error function can eliminate the influence of the non - linear factor of the transmitted - signal part on the phase.

[0013] In some alternative embodiments, the intermediate - frequency signal is multiplied by the preset phase - error function through the following formula to obtain a signal after the first processing: where S IF (t) is the intermediate - frequency signal, is the preset phase - error function, S ε (t) is the non - linear factor of the transmitted - signal part, and the is in a conjugate relationship with the S ε (t), is the non - linear factor of the received - signal part, S r_IF (t) is the linear component in the intermediate - frequency signal, and S IF1 (t) is the signal after the first processing.

[0014] In some alternative embodiments, performing anti - skew filtering on the echo signal after eliminating the non - linear factor of the transmitted - signal part to obtain a filtered echo signal includes: multiplying the signal after the first processing by a preset anti - skew filtering function to obtain a signal after the second processing, and the signal after the second processing contains a residual phase error aligned in time. After the first processing, the non - linear factor of the transmitted - signal part no longer exists in the signal. At this time, only the non - linear factor of the received - signal part has not been eliminated. The non - linear factor of the received - signal part is the residual phase error in the signal after the first processing, but they are not aligned in time and cannot be directly compensated. Therefore, it is necessary to make the residual phase error aligned in time based on the anti - skew filtering function before subsequent compensation can be carried out.

[0015] In some alternative embodiments, the signal after the first processing is multiplied by the preset anti - skew filtering function through the following formula to obtain a signal after the second processing: where SIF1 (t) is the signal after the first processing, q -a (t) is the preset anti-torsional skew filtering function, is the residual phase error, is the residual phase error aligned in time, S r_IF (t) is the linear component in the intermediate frequency signal, S IF2 (t) is the signal after the second processing.

[0016] In some alternative embodiments, compensating for the residual phase error in the filtered echo signal to obtain a non-linearly compensated echo signal includes: constructing a compensation function according to the residual phase error aligned in time; multiplying the signal after the second processing by the compensation function to obtain a signal after the third processing, and using the signal after the third processing as the non-linearly compensated echo signal. After being processed by the anti-torsional skew filter, the residual phase error has been aligned in time. At this time, multiplying the signal after the second processing by the compensation function constructed based on the residual phase error aligned in time can remove the non-linear factor of the received signal part, and thus complete the removal of all non-linear factors in the echo signal, that is, the non-linear compensation of the echo signal.

[0017] In some alternative embodiments, the signal after the second processing is multiplied by the compensation function through the following formula to obtain a signal after the third processing: wherein, S IF2 (t) is the signal after the second processing, S ε,a (t) is the compensation function, is the residual phase error aligned in time, S r_IF (t) is the linear component in the intermediate frequency signal, S IF3 (t) is the signal after the third processing.

[0018] In some alternative embodiments, anti-torsional skew filtering the echo signal after eliminating the non-linear factor of the transmitted signal part to obtain a filtered echo signal includes: performing discrete spectrum analysis on the echo signal after eliminating the non-linear factor of the transmitted signal part, and determining whether each frequency component is within a first preset range; determining the frequency components within the first preset range among the frequency components as the retained frequency components; and obtaining the filtered echo signal based on the signal obtained by performing inverse Fourier transform on the retained frequency components.

[0019] In some alternative embodiments, the discrete spectrum analysis of the echo signal after eliminating the non-linear factor of the transmitted signal portion includes: performing a windowing process on the echo signal after eliminating the non-linear factor of the transmitted signal portion to obtain a windowed echo signal, and performing discrete spectrum analysis on the windowed echo signal; the filtered echo signal obtained by performing an inverse frequency domain transform on the signal based on the retained frequency components includes: performing an unwindowing process on the signal obtained by performing an inverse frequency domain transform on the retained frequency components, and obtaining a filtered echo signal based on the signal obtained after the unwindowing process.

[0020] In some alternative embodiments, after obtaining the echo signal after non-linear compensation, it further includes: processing the signal after non-linear compensation to obtain at least one parameter of the distance, speed, and angle of the target object. Description of the Drawings

[0021] One or more embodiments are exemplarily illustrated by pictures in the corresponding drawings, and these exemplary illustrations do not constitute a limitation on the embodiments.

[0022] Figure 1 It is a schematic diagram of the ranging principle of an FMCW radar system in an ideal state;

[0023] Figure 2 It is a schematic diagram of the influence of non-linearity on the ranging of an FMCW radar system;

[0024] Figure 3 It is a flowchart of a signal processing method provided by an embodiment of the present application;

[0025] Figure 4 It is a flowchart of eliminating the non-linear factor of the transmitted signal portion in the echo signal by using a preset phase error function in an embodiment of the present application;

[0026] Figure 5 It is a schematic diagram of the implementation process of an anti-skew filtering provided by an embodiment of the present application;

[0027] Figure 6 It is a flowchart of compensating the residual phase error in the filtered echo signal to obtain an echo signal after non-linear compensation in an embodiment of the present application;

[0028] Figure 7 It is a schematic diagram of the non-linear compensation process of an FMCW complex sampling system in another embodiment of the present application;

[0029] Figure 8 It is a comparison diagram of the distance spectra before and after FMCW non-linear compensation in another embodiment of the present application;

[0030] Figure 9 It is a schematic diagram of the process of non - linear compensation of the FMCW real - sampling system in another embodiment of the present application.

[0031] Figure 10 It is a schematic diagram of the process of non - linear compensation of the FMCW sampling system and the compensation results of each step in another embodiment of the present application;

[0032] Figure 11 It is a schematic diagram of an integrated circuit provided in another embodiment of the present application;

[0033] Figure 12 It is a schematic diagram of a signal processing module provided in another embodiment of the present application. Detailed implementation manners

[0034] To make the objectives, technical solutions, and advantages of the embodiments of the present application clearer, the following will elaborate on each embodiment of the present application with reference to the accompanying drawings. However, those of ordinary skill in the art can understand that in each embodiment of the present application, many technical details are provided to help readers better understand the present application. However, even without these technical details and various changes and modifications based on the following embodiments, the technical solutions claimed in the present application can still be implemented. The following division of each embodiment is for convenience of description and should not constitute any limitation to the specific implementation manner of the present application. Each embodiment can be combined and cross - referenced with each other on the premise of no contradiction.

[0035] Taking radar and vehicle - mounted radar as examples below, the signal processing method in the embodiments of the present application will be described in detail. However, those skilled in the art should understand that on the premise of no conflict, the relevant technical content recorded in this embodiment can also be equally applicable to other communication devices and other signal sources.

[0036] For a frequency - modulated continuous - wave (FMCW) radar system, a stepped - frequency continuous - wave (SFCW) radar system, etc., by using the frequency difference (i.e., beat frequency) between the transmitted signal and the signal returned from the target (also known as the reflected signal, received signal), the distance between the radar and the target can be calculated. This signal is also called the intermediate - frequency signal. Generally, the farther the distance between the radar and the target, the greater the frequency of the corresponding intermediate - frequency signal; the closer the distance between the radar and the target, the smaller the frequency of the corresponding intermediate - frequency signal. In an ideal state, the ranging principle of the FMCW radar system can be as Figure 1 shown Figure 1 There are two targets, one near and one far, in the scenario of

[0037] Due to the rapid change of frequency over time, the performance of an FMCW radar system depends to a large extent on the linearity of its transmitted signal. If the instantaneous frequency of the chirp of an FMCW radar system deviates from linearity (or, equivalently, the phase of the chirp of an FMCW radar system deviates from a quadratic function), it will cause multiple components to appear in the frequency of the intermediate-frequency signal, leading to the appearance of false sidelobes or false targets, a decrease in the signal-to-noise ratio of the FMCW radar system, a decrease in range resolution and accuracy, etc. The impact of nonlinearity on the ranging of an FMCW radar system can be as Figure 2 shown.

[0038] To improve range resolution and accuracy, hardware techniques and software techniques can be used to improve the linearity of the radar system's frequency sweep. The technical core of the hardware technique is to generate a frequency sweep signal with high linearity, while the technical core of the software technique is to use signal processing methods to compensate for the impact brought by the nonlinear part of the frequency sweep.

[0039] Solutions based on hardware techniques include using the control voltage of a VCO (Voltage control oscillator) to achieve the output of a signal with higher linearity, but this solution is susceptible to changes in the external environment (such as temperature and humidity changes). Another solution based on hardware techniques is to use DDS (Direct Digital Synthesizer) technology, but the transmission bandwidth of this technology is very limited and cannot well meet the actual needs.

[0040] The technical core of the software technique is to assume the echo delay of the reference point. The expression of an ideal transmitted signal can be represented as: where f c is the starting frequency point, α is the frequency sweep rate, and t is the time variable. When the transmitted signal hits a target at a distance of R, the received echo signal by the receiver can be represented as: where τ = 2(R + vt) / c, τ is the echo delay, and v is the speed of the target. After mixing, the intermediate-frequency signal corresponding to the echo signal can be represented as:

[0041] However, when there are nonlinear frequency components in the transmitted signal, the expression of the transmitted signal becomes: where ε(t) represents the phase introduced by the nonlinear component. The intermediate-frequency signal at this time can then be represented as: which will lead to a decrease in range resolution, a decrease in the signal-to-noise ratio of the system, and the appearance of false targets.

[0042] Assuming the echo delay of the reference point is to assume ε(t,τ ref ) = ε(t) - ε(t - τref ) ≈ τ ref ε′(t), when τ ref is very small, this assumption holds, τ ref is the echo delay of the reference point, ε(t) - ε(t - τ ref ) term can be directly obtained from the corresponding of the reference point. At this time, the non - linear response of the echoes of other points can be obtained through the following expression:

[0043] However, as introduced above, this assumption only holds within a very small distance range. And within this distance range, the farther away from the reference point, the worse the effect of this assumption. If you want to apply it to a radar system with a very wide distance of interest, you need to assume several reference points in different small intervals, which consumes a large amount of computing resources.

[0044] To solve the technical problem that the above - mentioned assumption of reference points has a high cost and is difficult to apply to a radar system with a relatively wide distance range of interest, an embodiment of the present application provides a signal processing method, which is applied to perform non - linear compensation after sampling the intermediate - frequency signal obtained from the echo signal, and can be specifically applied to a terminal or a processor. This embodiment and each of the following embodiments are described by taking the processor as an example. The implementation details of the signal processing method of this embodiment are specifically described below. The following content is only the implementation details provided for convenience of understanding and is not necessary for implementing this solution.

[0045] The specific process of the signal processing method of this embodiment can be as Figure 3 shown, including:

[0046] Step 101, use a preset phase error function to eliminate the non - linear factor of the transmitted signal part in the echo signal.

[0047] In specific implementation, generally, after mixing the received echo signal to obtain an analog intermediate - frequency signal and sampling it using an Analog - to - Digital Converter (ADC for short), the non - linear components in the echo signal can be gradually eliminated. The non - linear components in the echo signal can be considered to consist of the non - linearity of the transmitted signal part and the non - linearity in the received signal part. In this embodiment, the non - linear components in the two parts are gradually eliminated. Because the received signal is highly correlated with the transmitted signal, the processor can first eliminate the non - linear factor of the transmitted signal part and then eliminate the non - linear factor of the received signal part. Using a preset phase error function, the non - linear factor of the transmitted signal part in the echo signal can be well eliminated. Among them, the preset phase error function can be set by those skilled in the art according to actual needs such as design, hardware parameters, and application scenario requirements. The embodiments of the present application do not make specific limitations on this.

[0048] In one example, the waveform of the echo signal is a continuous wave whose frequency linearly changes with time. Such a continuous wave includes at least one of FMCW wave and SFCW wave, and the FMCW wave may further include MBC wave.

[0049] In one example, by using a preset phase error function to eliminate the non-linear factor of the transmitted signal part in the echo signal, it can be achieved through the following sub-steps as Figure 4 shown, specifically including:

[0050] Sub-step 1011: Mix and sample the echo signal based on the local oscillator (LO) signal, and an intermediate frequency signal corresponding to the echo signal can be obtained. As Figure 10 shown, it is possible to collect the intermediate frequency signal containing frequency non-linearity (collected non-linear deramped data), specifically, two intermediate frequency signals containing non-linear factors as shown on the right side of the figure.

[0051] Sub-step 1012: Multiply the intermediate frequency signal by the preset phase error function to obtain the signal after the first processing. The signal after the first processing is the signal with the non-linear factor of the transmitted signal part eliminated.

[0052] In a specific implementation, the echo signal cannot be directly subjected to non-linear compensation. The processor first mixes and samples the sampled echo signal based on the local oscillator signal to obtain the intermediate frequency signal corresponding to the echo signal. Then the processor processes the above intermediate frequency signal based on the preset phase error function to obtain the signal after the first processing. For example, the intermediate frequency signal can be multiplied by the preset phase error function to obtain the signal after the first processing, that is, the signal after the first processing is the signal with the non-linear factor of the transmitted signal part eliminated. In the intermediate frequency signal formed after the echo signal is mixed with the local oscillator signal, there are non-linear factors of the transmitted signal part and non-linear factors of the received signal part, which are reflected as phase changes in the signal. Multiplying the intermediate frequency signal by the preset phase error function can eliminate the influence of the non-linear factor of the transmitted signal part on the phase.

[0053] In one example, multiplying the intermediate frequency signal by the preset phase error function to obtain the signal after the first processing, as shown in Figure 7 the following, can be achieved through the following formula: In the formula, S IF (t) is the intermediate frequency signal, is the preset phase error function, S ε (t) is the non-linear factor of the transmitted signal part, and S ε(t) is in a conjugate relationship, is the non - linear factor of the received signal part, S r_IF (t) is the linear component in the intermediate - frequency signal, S IF1 (t) is the signal after the first processing. That is to say, the input of the above formula is the sampling of the intermediate - frequency signal of coherent detection, presented in the form of a finite matrix of complex numbers S IF [n], where n is the sampling index, and this matrix is multiplied element - by - element with the sampled values of the complex conjugate of the error function to eliminate the phase error generated by the transmitted signal. As Figure 10 shown, after non - linear processing at the transmitting end (transmitted non - linears removal), an intermediate - frequency signal with some non - linear factors (non - linear factors at the transmitting end) removed, as shown on the right side in Figure 10 can be obtained.

[0054] Step 102: Perform anti - skew filtering on the echo signal after eliminating the non - linear factors of the transmitted signal part to obtain a filtered echo signal, and the residual phase errors in the filtered echo signal are aligned in time.

[0055] In a specific implementation, in the echo signal after eliminating the non - linear factors of the transmitted signal part, there are still non - linear components of the received signal part, but these non - linear components of the received signal part are not aligned in time and cannot be directly eliminated. At this time, anti - skew filtering can be performed on the echo signal after eliminating the non - linear factors of the transmitted signal part to obtain a filtered echo signal, and the residual phase errors (i.e., non - linear components of the received signal part) in the filtered echo signal are aligned in time and can be eliminated subsequently.

[0056] In an example, when the processor performs anti - skew filtering on the echo signal after eliminating the non - linear factors of the transmitted signal part to obtain a filtered echo signal, the signal after the first processing can be multiplied by a preset anti - skew filtering function to obtain a signal after the second processing. The signal after the second processing contains residual phase errors that are aligned in time. There are no non - linear factors of the transmitted signal part in the signal after the first processing. At this time, only the non - linear factors of the received signal part have not been eliminated. The non - linear factors of the received signal part are the residual phase errors in the signal after the first processing, but they are not aligned in time and cannot be directly compensated. Therefore, based on the anti - skew filtering function, the residual phase errors can be aligned in time before subsequent compensation can be carried out.

[0057] In an example, when the processor multiplies the signal after the first processing by a preset anti - skew filtering function to obtain a signal after the second processing, as Figure 7 shown, it can be achieved by the following formula: In the formula, S IF1 (t) is the signal after the first processing, and q -a (t) is a preset anti-torsional skew filtering function, is the residual phase error, is the residual phase error aligned in time, and S r_IF (t) is the linear component in the intermediate frequency signal, and S IF2 (t) is the signal after the second processing. q a (t) represents a quadratic phase filter, which can be a dispersion filter, that is, by introducing a group delay positively correlated with the frequency, its Fourier transform has the following characteristics: That is to say, the obtained array S IF1 [n] passes through a digital anti-torsional skew filter to obtain an output array S IF2 [n], where the residual phase errors of the received signals are aligned in time. As Figure 10 shown, after the processing in the range dimension (range deskew), as shown in the right side of Figure 10 , the two intermediate frequency signals are aligned in the time dimension.

[0058] In one example, the processor can perform anti-torsional skew filtering on the echo signal after eliminating the non-linear factor of the transmitted signal in the frequency domain. The processor first performs discrete spectrum analysis on the echo signal after eliminating the non-linear factor of the transmitted signal, converts it from the time domain to the frequency domain, determines whether each frequency component is within the first preset range, determines the frequency components within the first preset range among each frequency component as the reserved frequency components, and then performs an inverse Fourier transform on the reserved frequency components to obtain the filtered echo signal. Frequency domain processing is faster and can improve the efficiency of non-linear compensation. Among them, the first preset range can be set by those skilled in the art according to actual needs.

[0059] In one example, when the processor performs discrete spectrum analysis on the echo signal after eliminating the non-linear factor of the transmitted signal, it can first perform windowing processing on the echo signal after eliminating the non-linear factor of the transmitted signal to obtain the windowed echo signal, and then perform discrete spectrum analysis on the windowed echo signal. Similarly, when obtaining the filtered echo signal based on the signal obtained by performing an inverse Fourier transform on the reserved frequency components, first perform windowing removal processing on the signal obtained by performing an inverse Fourier transform on the reserved frequency components, and then obtain the filtered echo signal based on the signal obtained after windowing removal processing. Windowing processing can improve the quality and performance of the signal, reduce noise, thereby improving the effect of non-linear compensation, and windowing processing can be implemented through a window function.

[0060] In some examples, before windowing the echo signal after eliminating the non - linear factor of the transmitted signal part, zero - padding processing can be performed first. Correspondingly, after obtaining the signal after inverse windowing, zero - padding removal processing is also required. Zero - padding processing can preserve the original input size and maintain the stability of the input signal. Figure 5 The figure shows a schematic diagram of the implementation process of a deskew filter. Specifically, for the signal to be processed, zero - padding processing (Zero padding), windowing processing (Window), FFT, frequency - domain filtering (Frequency), IFFT, inverse windowing processing (Inverse window), and zero - padding removal processing (Padd remove) are performed in sequence; among them, the FFT step performed on the data after windowing processing is the above - mentioned multiplication of the intermediate - frequency signal by the preset phase - error function to obtain the signal S iF1 (t) after the first processing. The frequency - domain filtering step is the above - mentioned multiplication of the signal after the first processing by the preset deskew - filter function to obtain the signal S IF2 (t) after the second processing. The IFFT step is to multiply the signal after the second processing by the compensation function to obtain the signal S IF3 (t) after the third processing, as shown in step 103 below.

[0061] Step 103: Compensate the residual phase error in the filtered echo signal to obtain the non - linearly compensated echo signal.

[0062] In a specific implementation, in the echo signal after deskew filtering, the residual phase errors are aligned in time. At this time, the processor can directly compensate the non - linear components of the received signal part, that is, compensate the residual phase error in the filtered echo signal to obtain the non - linearly compensated echo signal.

[0063] In one example, for the processor to compensate the residual phase error in the filtered echo signal to obtain the non - linearly compensated echo signal, it can be achieved through the sub - steps as Figure 6 shown, specifically including:

[0064] Sub - step 1031: Construct a compensation function according to the residual phase errors aligned in time.

[0065] Sub - step 1032: Multiply the signal after the second processing by the compensation function to obtain the signal after the third processing, and use the signal after the third processing as the non - linearly compensated echo signal.

[0066] In a specific implementation, the residual phase error in the signal after the second processing is already aligned in time. Eliminating the non-linear components in the received signal part is to compensate for this residual phase error that is aligned in time. At this time, the processor constructs a compensation function based on the residual phase error that is aligned in time, and then multiplies the signal after the second processing by the compensation function to obtain the signal after the third processing. The signal after the third processing is used as the echo signal after non-linear compensation. After being processed by the anti-skew filter, the residual phase error is already aligned in time. At this time, multiplying the signal after the second processing by the compensation function constructed based on the residual phase error that is aligned in time can remove the non-linear factors in the received signal part, and thus complete the removal of all non-linear factors in the echo signal, that is, the non-linear compensation of the echo signal.

[0067] In one example, the processor multiplies the signal after the second processing by the compensation function to obtain the signal after the third processing, as Figure 7 shown, which can be achieved by the following formula: In the formula, S IF2 (t) is the signal after the second processing, S ε,a (t) is the compensation function, is the residual phase error that is aligned in time, S r_IF (t) is the linear component in the intermediate frequency signal, S IF3 (t) is the signal after the third processing. That is to say, S IF2 [n] is multiplied element by element with the residual phase error function S ε,a [n] to eliminate the residual phase error generated by the received signal. As Figure 10 shown, after the residual phase error compensation (non-linearities compensation), the compensated signal as shown on the right side in Figure 10 is obtained, and in the time dimension, the intermediate frequency signal with relatively flat frequency.

[0068] In this embodiment, when performing nonlinear compensation on the sampled echo signal, first use a preset phase error function to eliminate the nonlinear factor of the transmitted signal part in the echo signal, and then perform anti-skew filtering on the echo signal after eliminating the nonlinear factor of the transmitted signal part to obtain a filtered echo signal. The residual phase errors in the filtered echo signal are aligned in time. Finally, compensate for the residual phase errors in the filtered echo signal to obtain a nonlinearly compensated echo signal. Considering that the general hardware nonlinear compensation method in the industry is easily affected by changes in the external environment and has a limited transmission bandwidth, and the general software nonlinear compensation method in the industry has a limited applicable distance range and cannot perform linear compensation on a radar system with a relatively wide distance range of interest. Therefore, in the embodiment of this application, the nonlinear factor in the echo signal is regarded as a quantity that varies with distance, and nonlinear compensation is performed on the transmitting side and the receiving side in sequence, effectively improving the linearity of the frequency sweep of the radar system, not only reducing costs, but also performing well in a radar system with a relatively wide distance range of interest.

[0069] Specifically, refer to Figure 8 as shown in Figure 8 where the ordinate is the amplitude spectrum (dB) and the abscissa is the frequency (MHz). The solid line is the spectrum line before compensation, and the dashed line is the spectrum line after compensation. It can be clearly seen from the figure that when there is nonlinear adjustment, some extra frequency components (i.e., spikes around the peak) will appear near the peak of the target shown by the solid line. These frequency components are easily estimated as target data (i.e., form false targets) after velocity dimension FFT. After compensation, in the spectrum line presented by the dashed line, the frequency components near the peak are significantly and effectively suppressed. Comparing the spectrum line presented by the dashed line after compensation, it can be seen that after the compensation operation of the embodiment of this application, the above-mentioned extra frequency components are effectively suppressed, thus verifying the effectiveness of the compensation method described in the embodiment of this application.

[0070] It should be noted that the nonlinear compensation method described in the embodiment of this application can be applied to real-sampling or complex-sampling systems. For example, Figure 7 shows the flow architecture diagram applicable to a complex-sampling system, and based on Figure 7 , when performing the above-mentioned nonlinear compensation for a real-sampling system, a corresponding digital mixer can be added, that is, Figure 9 shows the flow architecture diagram.

[0071] In some alternative embodiments, after obtaining the echo signal with non-linear compensation, the processor may process the signal with non-linear compensation to obtain at least one parameter of the distance, speed, and angle of the target object.

[0072] The step division of the above various methods is only for clear description. During implementation, they can be combined into one step or some steps can be split into multiple steps. As long as the same logical relationship is included, they are all within the protection scope of this patent; adding insignificant modifications or introducing insignificant designs to the algorithm or process, but without changing the core design of its algorithm and process, are all within the protection scope of this patent.

[0073] Another embodiment of this application relates to a computer-readable storage medium storing a computer program. When the computer program is executed by a processor, the method embodiments described above are implemented.

[0074] That is, those skilled in the art can understand that all or part of the steps in implementing the above-described embodiment methods can be completed by instructing relevant hardware through a program. This program is stored in a storage medium and includes several instructions to enable a device (which can be a single-chip microcomputer, a chip, etc.) or a processor to execute all or part of the steps of the methods described in various embodiments of this application (such as the signal recovery method, etc.). The aforementioned storage medium includes: various media such as USB flash drives, mobile hard disks, read-only memories (ROM), random access memories (RAM), magnetic disks, or optical discs that can store program codes.

[0075] Another embodiment of this application relates to an integrated circuit. The details of the integrated circuit in this embodiment will be specifically described below. The following content is only implementation details provided for convenient understanding and is not necessary for implementing this solution. The schematic diagram of the integrated circuit in this embodiment can be as Figure 11 shown, and may include a signal transceiver channel 201 and a signal processing module 202. The signal transceiver channel 201 can be used to transmit radio signals and receive the echo signals formed by the reflection of the radio signals by the target object; the signal processing module 202 can be used to perform non-linear compensation on the sampled signals of the intermediate frequency signals obtained based on the echo signals according to the signal processing method described above.

[0076] In some examples, the signal processing module 202 can be as Figure 12As shown, it may include a first compensation unit 2021, a skew-resistant filtering unit 2022, and a second compensation unit 2023 connected in sequence; the first compensation unit 2021 may be used to eliminate the non-linear factor of the transmitted signal part in the echo signal by using a preset phase error function, and the skew-resistant filtering unit 2022 may be used to perform skew-resistant filtering on the echo signal after eliminating the non-linear factor of the transmitted signal part to obtain a filtered echo signal, and the residual phase errors in the filtered echo signal are aligned in time; the second compensation unit 2023 may be used to compensate for the residual phase errors in the filtered echo signal to obtain a non-linearly compensated echo signal.

[0077] It is worth mentioning that each module involved in this embodiment is a logic module. In practical applications, a logic unit may be a physical unit, a part of a physical unit, or may be implemented by a combination of multiple physical units. In addition, in order to highlight the innovative part of this application, units that are not closely related to solving the technical problems proposed in this application are not introduced in this embodiment, but this does not mean that there are no other units in this embodiment.

[0078] In some alternative embodiments, the above integrated circuit may be a millimeter-wave radar chip or a lidar chip (such as an FMCW lidar chip), etc., for obtaining information such as the distance, angle, speed, shape, size, surface roughness, and dielectric properties of a target. Optionally, the integrated circuit may be an Antenna-In-Package (AiP) chip structure, an Antenna-On-Package (AoP) chip structure, or an Antenna-On-Chip (AoC) chip structure, etc.

[0079] In an alternative embodiment, different integrated circuits (such as chips) may be combined with each other to form a cascade structure. For the sake of simplicity, it will not be elaborated here, but it should be understood that all technologies that those skilled in the art should be aware of based on the content recorded in this application should be included within the scope recorded in this application.

[0080] Another embodiment of the present application relates to a radio device, which includes a carrier, an integrated circuit as described above disposed on the carrier, and an antenna for transmitting and receiving radio signals disposed on the carrier. The antenna can be integrated with the integrated circuit into an integrated device and disposed on the carrier (i.e., at this time, the antenna can be the antenna disposed in the AiP or AoC structure), and the integrated circuit can also be two discrete components from the antenna, and a system-on-chip (SoC) structure is formed through connection. Among them, the carrier can be a printed circuit board (PCB), such as a development board, a data acquisition board, or the main board of a device, etc., and the first transmission line can be a PCB trace.

[0081] In some alternative embodiments, the present application further provides a terminal device, which may include a device body and a radio device as described in any of the above embodiments disposed on the device body; wherein, the radio device can be used to implement functions such as target detection and / or wireless communication.

[0082] Specifically, based on the above embodiments, in some alternative embodiments of the present application, the radio device can be disposed outside the device body or inside the device body, and in other alternative embodiments of the present application, a part of the radio device can also be disposed inside the device body and a part can be disposed outside the device body. The embodiments of the present application do not limit this, and it can be determined according to specific circumstances.

[0083] In some alternative embodiments, the above device body can be components and products applied in fields such as smart cities, smart homes, transportation, smart homes, consumer electronics, security monitoring, industrial automation, in-cabin detection (such as smart cockpits), medical devices, and health care. For example, the device body can be a smart transportation device (such as a car, a bicycle, a motorcycle, a ship, a subway, a train, etc.), a security device (such as a camera), a liquid level / flow rate detection device, a smart wearable device (such as a bracelet, glasses, etc.), a smart home device (such as a sweeping robot, a door lock, a TV, an air conditioner, a smart light, etc.), various communication devices (such as a mobile phone, a tablet computer, etc.), and various industrial robotic arms (or robots) such as a barrier gate, a smart traffic indicator light, a smart sign, a traffic camera, etc., and can also be various instruments for detecting vital sign parameters and various devices equipped with the instrument, such as in-car vital sign detection in a car, indoor personnel monitoring, smart medical devices, consumer electronic devices, etc.

[0084] The radio device can be the radio device described in any of the embodiments of the present application. The structure and working principle of the radio device have been described in detail in the above embodiments and will not be elaborated here one by one.

[0085] It should be noted that radio devices can achieve functions such as target detection and / or communication by transmitting and receiving radio signals, so as to provide detection target information and / or communication information to the device body, thereby assisting or even controlling the operation of the device body.

[0086] For example, when the above-mentioned device body is applied to an Advanced Driving Assistance System (ADAS), radio devices as vehicle-mounted sensors (such as millimeter-wave radars, lidar, etc.) can assist the ADAS system to achieve application scenarios such as adaptive cruise, Autonomous Emergency Braking (AEB), Blind Spot Detection (BSD), Lane Change Assist (LCA), Rear Cross Traffic Alert (RCTA), parking assistance, warning of vehicles behind, anti-collision, pedestrian detection, etc. At the same time, it can also be applied to application scenarios such as anti-collision when opening the door of a car.

[0087] The technical features of the above-described embodiments can be combined arbitrarily. For the sake of brevity of description, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered as the scope described in this specification.

[0088] The above-described embodiments only represent the preferred embodiments of the present application and the technical principles applied. The description is relatively specific and detailed, but it cannot be understood as a limitation to the scope of the invention patent. Those skilled in the art can make various obvious changes, re-adjustments and substitutions without departing from the protection scope of the present application. Therefore, although the present application has been described in more detail through the above embodiments, the present application is not limited to the above embodiments. Without departing from the concept of the present application, more other equivalent embodiments can be included, and the protection scope of the present application is determined by the scope of the appended claims.

Claims

1. A signal processing method, characterized in that, Applied to non-linear compensation after sampling the intermediate frequency signal obtained from the echo signal, the method includes: Using a preset phase error function to eliminate the non-linear factor of the transmitted signal part in the echo signal; Performing anti-skew filtering on the echo signal after eliminating the non-linear factor of the transmitted signal part to obtain a filtered echo signal, where the residual phase error in the filtered echo signal is aligned in time; Compensating the residual phase error in the filtered echo signal to obtain a non-linearly compensated echo signal.

2. The signal processing method according to claim 1, wherein The step of using a preset phase error function to eliminate the non-linear factor of the transmitted signal part in the echo signal includes: Mixing the echo signal based on the local oscillator signal to obtain an intermediate frequency signal corresponding to the echo signal; Multiplying the intermediate frequency signal by a preset phase error function to obtain a signal after the first processing, and the signal after the first processing is a signal with the non-linear factor of the transmitted signal part eliminated.

3. The signal processing method according to claim 2, characterized in that, Multiplying the intermediate frequency signal by a preset phase error function through the following formula to obtain a signal after the first processing: Among them, S IF (t) is the intermediate frequency signal, is the preset phase error function, S ε (t) is the non-linear factor of the transmission signal part, the and the S ε (t) is in a conjugate relationship, is the non-linear factor of the received signal part, S r_IF (t) is the linear component in the intermediate frequency signal, S IF1 (t) is the signal after the first processing.

4. The signal processing method according to claim 2, wherein The step of performing anti-skew filtering on the echo signal after eliminating the non-linear factor of the transmitted signal part to obtain a filtered echo signal includes: Multiplying the signal after the first processing by a preset anti-skew filtering function to obtain a signal after the second processing, and the signal after the second processing contains a residual phase error aligned in time.

5. The signal processing method according to claim 4, wherein Multiplying the signal after the first processing by a preset anti-skew filtering function through the following formula to obtain a signal after the second processing: Among them, S IF1 (t) is the signal after the first processing, q -a (t) is the preset anti-torsional skew filtering function, is the residual phase error, is the residual phase error aligned in time, S r_IF (t) is the linear component in the intermediate frequency signal, S IF2 (t) is the signal after the second processing.

6. The signal processing method according to claim 4, characterized in that The step of compensating the residual phase error in the filtered echo signal to obtain a non-linearly compensated echo signal includes: Constructing a compensation function according to the residual phase error aligned in time; Multiplying the signal after the second processing by the compensation function to obtain a signal after the third processing, and taking the signal after the third processing as the non-linearly compensated echo signal.

7. The signal processing method according to claim 6, wherein Multiplying the signal after the second processing by the compensation function through the following formula to obtain a signal after the third processing: where S IF2 (t) is the signal after the second processing, S ε,a (t) is the compensation function, is the residual phase error aligned in time, S r_IF (t) is the linear component in the intermediate frequency signal, S IF3 (t) is the signal after the third processing.

8. The signal processing method according to any one of claims 1 to 3, characterized in that The step of performing anti-skew filtering on the echo signal after eliminating the non-linear factor of the transmitted signal part to obtain a filtered echo signal includes: Performing discrete spectrum analysis on the echo signal after eliminating the non-linear factor of the transmitted signal part to determine whether each frequency component is within a first preset range; Determining the frequency components within the first preset range among the frequency components as the retained frequency components; Obtaining the filtered echo signal based on the signal obtained by performing inverse Fourier transform on the retained frequency components.

9. The signal processing method according to claim 8, wherein The step of performing discrete spectrum analysis on the echo signal after eliminating the non-linear factor of the transmitted signal part includes: Performing windowing processing on the echo signal after eliminating the non-linear factor of the transmitted signal part to obtain a windowed echo signal, and performing discrete spectrum analysis on the windowed echo signal; The step of obtaining the filtered echo signal based on the signal obtained by performing inverse Fourier transform on the retained frequency components includes: Perform windowing on the signal obtained by performing inverse frequency domain transformation on the retained frequency components, and obtain the filtered echo signal based on the signal obtained after the windowing process.

10. The signal processing method according to any one of claims 1 to 7, characterized in that, After obtaining the echo signal after non-linear compensation, it further includes: Process the signal after non-linear compensation to obtain at least one parameter of the distance, speed, and angle of the target object.

11. A computer-readable storage medium storing a computer program, characterized in that, When the computer program is executed by a processor, it implements the signal processing method described in any one of claims 1 to 10.

12. An integrated circuit, characterized in that, It includes: A signal transceiver channel, which can be used to transmit radio signals and receive the echo signals formed by the reflection of the radio signals by the target. A signal processing module, which can be used to perform non-linear compensation on the sampled signals of the intermediate frequency signals obtained based on the echo signals according to the signal processing method described in any one of claims 1 to 10.

13. The integrated circuit according to claim 12, wherein, The signal processing module includes: A first compensation unit, which is used to eliminate the non-linear factor of the transmitted signal part in the echo signal by using a preset phase error function. An anti-skew filtering unit, which is used to perform anti-skew filtering on the echo signal after eliminating the non-linear factor of the transmitted signal part to obtain the filtered echo signal, and the residual phase error in the filtered echo signal is aligned in time. A second compensation unit, which is used to compensate the residual phase error in the filtered echo signal to obtain the echo signal after non-linear compensation.

14. A radio device, characterized in that, It includes: A carrier; The integrated circuit described in any one of claims 12 to 13 is disposed on the carrier; An antenna, which is disposed on the carrier and is used to transmit and receive radio signals.

15. A terminal device, characterized in that, It includes: The device body; The radio device described in claim 14 is disposed on the device body, and the radio device is used for target detection and / or communication.

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