Broadband Phase-Frequency Compensation Filter and Its Construction Method, Broadband Phase-Frequency Compensation Method, Medium and Device

Abstract

Embodiments of the present application disclose a broadband phase-frequency compensation filter and its construction method, a broadband phase-frequency compensation method, a medium, and a device, which relate to the field of communication technologies. The broadband phase-frequency compensation filter in the present application is composed of a cascaded IIR all-pass phase-frequency compensation filter and a fixed phase compensation module. After the signal is compensated by the IIR all-pass phase-frequency compensation filter, the fixed phase compensation module compensates for the fixed phase deviation value between the phase compensated by the IIR all-pass phase-frequency compensation filter and the actual phase characteristic of the system to be measured. The fixed phase compensation module in the form of FFT-IFFT filtering compensates for the fixed phase value at each frequency point, making up for the deficiency brought about by the traditional all-pass filter design that cannot capture the fixed phase of all frequency points when calculating the group delay, thereby realizing complete compensation for the phase information of the acquisition system.

Description

Technical Field

[0001] The present application relates to the field of communication technologies, and particularly to a broadband phase-frequency compensation filter and a method for constructing the same, a broadband phase-frequency compensation method, a medium, and a device. Background Art

[0002] In an actual broadband acquisition system, the non-ideal characteristics of the radio frequency circuit will make it difficult to achieve the conditions of flat amplitude-frequency response and linear phase-frequency response across the entire bandwidth. Therefore, it is necessary to perform corresponding amplitude-frequency and phase-frequency response compensations for the entire bandwidth system. However, the amplitude-frequency and phase-frequency response compensation calculations based on a comprehensive filter bank are costly and cannot solve the calibration imbalance phenomenon caused by calibration accuracy. To solve the above calibration imbalance problem, in engineering implementation, the amplitude-frequency and phase-frequency compensations are generally completed by respective filters.

[0003] In actual system applications, considering factors such as system non-ideal characteristics and impedance mismatch may cause a fixed phase shift across the entire frequency band. This fixed phase shift will cause signal distortion in the system even after conventional phase-frequency compensation based on group delay is completed. The reason is that during the calculation of group delay, the phase difference between adjacent frequency points will cancel out this fixed phase shift, ultimately resulting in the phase-frequency correction based on the traditional all-pass IIR filter being unable to capture this fixed phase shift, and thus unable to achieve complete compensation for the phase information, resulting in no effective guarantee for high-quality distortion-free signal acquisition in the acquisition system. Summary of the Invention

[0004] The main objective of the present application is to provide a broadband phase-frequency compensation filter and a method for constructing the same, a broadband phase-frequency compensation method, a medium, and a device, aiming to solve the problem in the prior art that complete compensation for phase information cannot be achieved.

[0005] To achieve the above objective, the technical solutions adopted in the embodiments of the present application are as follows:

[0006] In a first aspect, an embodiment of the present application provides a broadband phase-frequency compensation filter, including:

[0007] A cascaded IIR all-pass phase-frequency compensation filter and a fixed phase compensation module, where the fixed phase compensation module is constructed based on the FFT-IFFT filtering form, and the fixed phase compensation module is used to compensate for the fixed phase deviation value between the phase compensated by the IIR all-pass phase-frequency compensation filter and the actual phase characteristics of the system to be measured.

[0008] In a second aspect, an embodiment of the present application provides a method for constructing a broadband phase-frequency compensation filter, which is used to construct the broadband phase-frequency compensation filter provided in the first aspect above, and includes the following steps:

[0009] Obtain an estimated group delay value of the system to be measured according to the estimated phase value of the system to be measured;

[0010] According to the group delay estimation value, obtain the coefficients of the IIR all-pass phase-frequency compensation filter and construct the IIR all-pass phase-frequency compensation filter;

[0011] According to the pole distribution of the IIR all-pass phase-frequency compensation filter, obtain the phase compensation value;

[0012] According to the actual phase value and the phase compensation value of the system to be measured, obtain the fixed phase deviation value;

[0013] Based on the fixed phase deviation value, construct a fixed phase compensation module in the form of FFT-IFFT filtering;

[0014] Cascade the IIR all-pass phase-frequency compensation filter and the fixed phase compensation module to obtain a broadband phase-frequency compensation filter.

[0015] In a possible implementation manner of the second aspect, before obtaining the group delay estimation value of the system to be measured according to the phase estimation value of the system to be measured, the construction method further includes:

[0016] According to the target phase value and the phase-frequency response of the system to be measured, obtain the phase estimation value of the system to be measured; wherein, the target phase value is the phase value of the digital angular frequency after the Fourier transform of the time-domain average data.

[0017] In a possible implementation manner of the second aspect, before obtaining the phase estimation value of the system to be measured according to the target phase value and the phase-frequency response of the system to be measured, the construction method further includes:

[0018] Perform average denoising processing on the time-domain signal to obtain time-domain average data.

[0019] In a possible implementation manner of the second aspect, before performing average denoising processing on the time-domain signal to obtain time-domain average data, the construction method further includes:

[0020] Align the collected data based on the data alignment algorithm for peak search to obtain a time-domain signal.

[0021] In a third aspect, an embodiment of the present application provides a broadband phase-frequency compensation method, which uses the broadband phase-frequency compensation filter provided in the first aspect as described above, and includes the following steps:

[0022] Obtain an original signal;

[0023] Input the original signal into the broadband phase-frequency compensation filter to obtain a target signal.

[0024] In a possible implementation manner of the third aspect, inputting the original signal into the broadband phase-frequency compensation filter to obtain a target signal includes:

[0025] Input the original signal into the IIR all-pass phase-frequency compensation filter of the broadband phase-frequency compensation filter for the first compensation to obtain a first output signal;

[0026] Input the first output signal into the fixed-phase compensation module of the broadband phase-frequency compensation filter for the second compensation to obtain a target signal.

[0027] In a possible implementation manner of the third aspect, after inputting the original signal into the IIR all-pass phase-frequency compensation filter of the broadband phase-frequency compensation filter for the first compensation to obtain a first output signal, the compensation method further includes:

[0028] Obtain the positive and negative sign conditions of the zero-frequency signal according to the state of the fixed phase deviation value;

[0029] Inputting the first output signal into the fixed-phase compensation module of the broadband phase-frequency compensation filter for the second compensation to obtain a target signal includes:

[0030] Input the first output signal into the fixed-phase compensation module of the broadband phase-frequency compensation filter for the second compensation, and obtain the target signal based on the positive and negative sign conditions of the zero-frequency signal.

[0031] In a fourth aspect, an embodiment of the present application provides a computer-readable storage medium storing a computer program, which when loaded and executed by a processor, implements the construction method of the broadband phase-frequency compensation filter provided in any one of the above second aspects or the broadband phase-frequency compensation method provided in any one of the above third aspects.

[0032] In a fifth aspect, an embodiment of the present application provides an electronic device including a processor and a memory, wherein,

[0033] The memory is used to store a computer program;

[0034] The processor is used to load and execute the computer program so that the electronic device executes the construction method of the broadband phase-frequency compensation filter provided in any one of the above second aspects or the broadband phase-frequency compensation method provided in any one of the above third aspects.

[0035] Compared with the prior art, the beneficial effects of the present application are:

[0036] A broadband phase-frequency compensation filter, a method for constructing the same, a broadband phase-frequency compensation method, a medium, and a device proposed in an embodiment of the present application. The broadband phase-frequency compensation filter is composed of a cascaded IIR all-pass phase-frequency compensation filter and a fixed-phase compensation module. After the signal is compensated by the IIR all-pass phase-frequency compensation filter, the fixed-phase compensation module compensates for the fixed-phase deviation value between the phase compensated by the IIR all-pass phase-frequency compensation filter and the actual phase characteristic of the system to be measured. The fixed-phase compensation module in the form of FFT-IFFT filters compensates for the fixed-phase value at each frequency point, making up for the deficiency of the traditional all-pass filter design that cannot capture the fixed phase of all frequency points due to the calculation of group delay, thereby realizing the complete compensation of the phase information of the acquisition system. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 It is a schematic structural diagram of the broadband phase-frequency compensation filter provided by an embodiment of the present application;

[0038] Figure 2 It is a schematic structural diagram of an electronic device in the hardware operating environment related to an embodiment of the present application;

[0039] Figure 3 It is a schematic flowchart of the method for constructing the broadband phase-frequency compensation filter provided by an embodiment of the present application;

[0040] Figure 4 It is a schematic diagram of the relationship between the group delays corresponding to the respective phase values in the method for constructing the broadband phase-frequency compensation filter provided by an embodiment of the present application;

[0041] Figure 5 It is a schematic flowchart of the broadband phase-frequency compensation method provided by an embodiment of the present application;

[0042] Figure 6 It is a schematic flowchart of the broadband phase-frequency compensation method provided by an embodiment of the present application in an implementation manner;

[0043] Figure 7 It is a comparison schematic diagram of the unaligned time-domain signal and the aligned time-domain signal when the broadband phase-frequency compensation method provided by an embodiment of the present application is tested;

[0044] Figure 8 It is a comparison schematic diagram of the uncompensated original signal, the signal compensated by the traditional IIR all-pass filter, and the signal compensated by the broadband phase-frequency compensation method provided by an embodiment of the present application;

[0045] Figure 9 It is a comparison schematic diagram of the signal before processing the zero-frequency signal and the signal after processing the zero-frequency signal by the broadband phase-frequency compensation method provided by an embodiment of the present application;

[0046] Figure 10Schematic diagram of modules of the broadband phase-frequency compensation filter construction device provided by an embodiment of the present application;

[0047] Figure 11 Schematic diagram of modules of the broadband phase-frequency compensation device provided by an embodiment of the present application;

[0048] Markings in the figure: 101 - Processor, 102 - Communication bus, 103 - Network interface, 104 - User interface, 105 - Memory. Specific embodiments

[0049] It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0050] The current development trend of electronic systems is towards greater bandwidth, higher transmission rate, more information carrying, stronger anti-interference ability, etc. This requires test and measurement equipment to have a higher sampling rate and a larger analysis bandwidth. The improvement of the performance of high-speed broadband test and measurement equipment enables it to be directly applied to the distortionless capture of signals and time-domain waveform analysis in fields such as broadband communication, broadband radar, and broadband electronic countermeasures. In an actual broadband acquisition system, the non-ideal characteristics of the radio frequency circuit will make it difficult to achieve the conditions of flat amplitude-frequency response and linear phase-frequency response across the entire bandwidth. Therefore, corresponding amplitude-frequency and phase-frequency response compensation for the entire bandwidth system is required.

[0051] However, the calculation cost of amplitude-frequency and phase-frequency response compensation for a system based on an integrated filter bank is high, and it cannot solve the calibration imbalance phenomenon caused by calibration accuracy. Considering that the calculation of group delay in all-pass phase-frequency calibration is the negative reciprocal of the phase with respect to the digital angular frequency, when it comes to the case of dense sampling frequency points, small phase fluctuations between frequency points will cause large changes in the group delay result, which is not conducive to all-pass phase-frequency calibration using the group delay curve fitting method. In contrast, dense frequency points can improve the compensation accuracy for all-pass amplitude-frequency compensation. To solve the above calibration imbalance problem, engineering implementation generally completes amplitude-frequency and phase-frequency compensation with separate filters.

[0052] The all-pass amplitude-frequency correction is realized by designing a linear-phase FIR filter that does not affect the phase-frequency characteristic, while the all-pass phase-frequency correction is realized by designing an all-pass IIR filter that does not affect the amplitude-frequency characteristic. In practical system applications, a conventional FIR filter designed based on the least squares method can meet the requirements of precise all-pass amplitude-frequency compensation and correction. For all-pass phase-frequency compensation, the design idea of the all-pass IIR filter is to accurately fit the group delay characteristic of the system. Considering factors such as the non-ideal characteristics of the system and impedance mismatch, which may cause a fixed phase shift across the entire frequency band, this fixed phase shift will result in signal distortion in the system even after the conventional phase-frequency compensation based on group delay is completed. The reason is that during the calculation of the group delay, the phase difference between adjacent frequency points will cancel out this fixed phase shift, ultimately causing the phase-frequency correction based on the traditional all-pass IIR filter to be unable to capture this fixed phase shift, thus failing to achieve complete compensation of the phase information and effectively guaranteeing the acquisition of high-quality distortion-free signals in the acquisition system.

[0053] Therefore, as shown in the appendix Figure 1 The embodiment of the present application provides a broadband phase-frequency compensation filter, including:

[0054] A cascaded IIR all-pass phase-frequency compensation filter and a fixed phase compensation module, where the fixed phase compensation module is constructed based on the FFT-IFFT filtering form, and the fixed phase compensation module is used to compensate for the fixed phase deviation value between the phase compensated by the IIR all-pass phase-frequency compensation filter and the actual phase characteristic of the system to be measured.

[0055] In this embodiment, the broadband phase-frequency compensation filter is composed of a cascaded IIR all-pass phase-frequency compensation filter and a fixed phase compensation module. After the signal is compensated by the IIR all-pass phase-frequency compensation filter, the fixed phase compensation module compensates for the fixed phase deviation value between the phase compensated by the IIR all-pass phase-frequency compensation filter and the actual phase characteristic of the system to be measured. The fixed phase compensation module in the form of FFT-IFFT filtering compensates for the fixed phase value at each frequency point, making up for the deficiency of the traditional all-pass filter design that cannot capture the fixed phase at all frequency points during the calculation of the group delay, thereby achieving complete compensation of the phase information in the acquisition system.

[0056] Referring to the appendix Figure 2 Appendix Figure 2Schematic diagram of the structure of an electronic device for the hardware operating environment involved in the solution of the embodiment of the present application. The electronic device may include: a processor 101, such as a Central Processing Unit (CPU), a communication bus 102, a user interface 104, a network interface 103, and a memory 105. Among them, the communication bus 102 is used to realize the connection and communication between these components. The user interface 104 may include a display screen (Display), an input unit such as a keyboard (Keyboard). Optionally, the user interface 104 may further include a standard wired interface and a wireless interface. The network interface 103 may optionally include a standard wired interface and a wireless interface (such as a Wireless-Fidelity (WI-FI) interface). The memory 105 may optionally be a storage device independent of the aforementioned processor 101. The memory 105 may be a high-speed Random Access Memory (RAM) memory, or may be a stable non-volatile memory (Non-Volatile Memory, NVM), such as at least one disk memory; the processor 101 may be a general-purpose processor, including a central processor, a network processor, etc., or may also be a digital signal processor, an application-specific integrated circuit, a field-programmable gate array, or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components.

[0057] Those skilled in the art can understand that the structure shown in the appendix Figure 2 does not constitute a limitation on the electronic device, and may include more or fewer components than shown in the figure, or combine certain components, or have different component arrangements.

[0058] As shown in the appendix Figure 2 The memory 105, as a storage medium, may include an operating system, a network communication module, a user interface module, and a broadband phase-frequency compensation filter construction device or a broadband phase-frequency compensation device.

[0059] In the electronic device shown in the appendix Figure 2 the network interface 103 is mainly used for data communication with a network server; the user interface 104 is mainly used for data interaction with a user; the processor 101 and the memory 105 in the present application may be arranged in the electronic device. The electronic device calls the broadband phase-frequency compensation filter construction device or the broadband phase-frequency compensation device stored in the memory 105 through the processor 101, and executes the broadband phase-frequency compensation filter construction method or the broadband phase-frequency compensation method provided by the embodiment of the present application.

[0060] Referring to the appendix Figure 3, based on the hardware device of the foregoing embodiments, an embodiment of the present application provides a method for constructing a broadband phase-frequency compensation filter for constructing the broadband phase-frequency compensation filter provided in the embodiments of the present application, including the following steps:

[0061] S00: Obtain a phase estimation value of the system under test according to the target phase value and the phase-frequency response of the system under test; wherein, the target phase value is the phase value of the digital angular frequency after the Fourier transform of the time-domain average data.

[0062] In the specific implementation process, the goal of the acquisition system phase correction is to obtain a linear phase-frequency response, and the corresponding group delay is a fixed delay value that does not change with frequency. For example, the group delay value at a certain frequency point represents the time delay experienced by the signal at that frequency point after passing through the system. A fixed group delay value across the entire frequency band means that the signals at all frequency band points experience the same time delay after passing through the system. At this time, there is no distortion in the time-domain waveform of the signal. According to the group delay calculation formula, the estimation of the phase-frequency response of the system across the entire frequency band needs to consider the relative phase relationship between frequency points rather than the independent phase value of a single frequency point. Therefore, the sine sweep method used to obtain the all-pass amplitude-frequency response is no longer applicable to the estimation of the system phase-frequency response. On the contrary, a calibration excitation signal with broad-spectrum characteristics and a determined phase relationship between frequency components needs to be selected.

[0063] The methods for estimating the phase-frequency response of a broadband system can generally be divided into two categories: The first category is to set up a reference system through a synchronization relationship, use the calibration excitation signal collected by the reference system as a reference signal, and use the reference signal to find the relative phase relationship with the signal collected by the system under test as the phase reference value; the second category is to collect excitation signals with multiple harmonics having known fixed phase relationships, such as periodic narrow pulse comb-shaped spectrum signals. Since the measurement accuracy of the first category of methods is greatly affected by the synchronization accuracy, the present application will use a periodic narrow pulse comb-shaped spectrum signal as the excitation signal to obtain the phase-frequency response of the system under test. Therefore, the phase-frequency response of the system under test can be expressed as:

[0064]

[0065] where, under the condition of a fixed sampling rate, ω i is the digital angular frequency of the i-th frequency point of the system; is the phase-frequency response value of the output signal collected by the system under test; is the phase-frequency response value of the system input periodic narrow pulse comb-shaped spectrum excitation signal at ω i . Since the phase-frequency responses of the above two signals are known, the phase-frequency characteristics of the system under test itself can be directly calculated by formula (1). Let be the time-domain average data after the Fourier transform, and the phase value at the digital angular frequency ω i . Let Substituting into Equation (1) gives the phase estimation value of the system under test.

[0066] In one embodiment, before obtaining the phase estimation value of the system under test according to the target phase value and the phase-frequency response of the system under test, the construction method further includes:

[0067] Performing data alignment on the collected data by a data alignment algorithm based on peak search to obtain a time-domain signal;

[0068] Performing average denoising processing on the time-domain signal to obtain time-domain average data.

[0069] In the specific implementation process, to improve the estimation accuracy of the phase-frequency response of the system under test and avoid the group delay change caused by the small phase fluctuation caused by noise, this application eliminates noise by averaging multiple collected signals, and then calculates the system group delay. However, averaging multiple collected signals requires the same trigger condition. At the same time, the application of the data alignment algorithm can avoid waveform jitter caused by unstable triggering. This application proposes a data alignment algorithm based on peak search to align the actual collected data. Specifically:

[0070] Let the multiple collected signals to be aligned be X, and its size be N×N', where N is the number of time-domain signal points collected each time, and N' is the number of signal collection times. For the collected data X, first reorganize the collected signal size to K×MN', where K is defined as the number of sampling points of the single-cycle narrow pulse excitation signal, that is:

[0071]

[0072] f s is the system sampling frequency, and f c is the fundamental frequency of the narrow pulse excitation signal; M is defined as the number of multiples of the narrow pulse excitation signal period contained in N points collected each time, that is:

[0073]

[0074] floor(·) is the floor operation. Here, the remaining points after floor operation for each collected signal are discarded, that is, N - MK. Subsequently, interpolation processing is performed on each column of data, and finally a data matrix with a reorganized size of K'×MN' is obtained as X', where K' is the number of data points of the single-cycle narrow pulse excitation signal after interpolation. Second step, perform peak search on each column of data in the reorganized matrix X' to find its minimum value and its coordinate index value, that is Here, j represents the jth column of data in the matrix X'. Third step, sort where the column data corresponding to the minimum index value is used as a reference, and other column data are aligned to it. Let the minimum index value and its corresponding column be The number of points to be discarded at the left end for the data in the j-th column is:

[0075]

[0076] According to the delay points obtained above The data alignment needs to satisfy:

[0077]

[0078] Among them, is the misaligned data in the j-th column; is the data in the j-th column after alignment; The aligned time-domain signal is averaged and denoised to obtain:

[0079]

[0080] S10: According to the phase estimation value of the system to be measured, obtain the group delay estimation value of the system to be measured.

[0081] In the specific implementation process, the group delay of the system to be measured can be obtained according to the following formula:

[0082]

[0083] S20: According to the group delay estimation value, obtain the IIR all-pass phase-frequency compensation filter coefficients and construct an IIR all-pass phase-frequency compensation filter.

[0084] In the specific implementation process, after obtaining the group delay characteristic of the system, an IIR all-pass filter can be designed to fit the group delay of the system, thereby compensating for the phase distortion in the passband. Define the system function of the second-order cascade form of the IIR all-pass filter as:

[0085]

[0086] Among them, r p and θ p are respectively the modulus and phase angle of the p-th second-order section pole, and P is the order of the all-pass filter. According to the definition of the second-order section in formula (8), the relationship between the group delay of a single second-order section and the pole can be:

[0087]

[0088] At the same time, the integral of the group delay of a single second-order section in [0,π] is always:

[0089]

[0090] From (9) and (10), it can be seen that the value of the group delay increases with the increase of the pole modulus r p At this time, its integral curve will also become narrower and more concentrated at ω = θp Therefore, the graphical method can be used to cut the target group delay into P intervals with an area of 2π, and the group delay value of the system under test can be fitted by adjusting the modulus and phase angle of each second-order section pole of the all-pass filter. The finally obtained all-pass filter coefficients are the modulus and phase angle of each second-order section pole, such as (r p , θ p ), where p = 1,..., P / 2.

[0091] S30: Obtain the phase compensation value according to the pole distribution of the IIR all-pass phase compensation filter.

[0092] S40: Obtain the fixed phase deviation value according to the actual phase value and the phase compensation value of the system under test.

[0093] In the specific implementation process, according to the pole distribution of the all-pass filter, the actual phase compensation value of each frequency point can be calculated using the following formula:

[0094]

[0095] Since the graphical method mentioned in the previous steps for generating all-pass filter coefficients requires cutting the target group delay into P intervals with an area of 2π, to ensure the causality of the target group delay, compared with the inverted value of the actual phase of the system under test, such as there will be a linear delay of D extra -P - δ DUT , where D extra is an additional delay parameter used to control the area of the target group delay to be exactly 2πP, and δ DUT is a small linear delay error. On the basis, remove the linear delay D extra -P - δ DUT added additionally for generating filter coefficients. The difference between it and the inverse of the actual phase value of the system is the phase deviation that cannot be compensated by the all-pass filter, that is, the fixed phase deviation value. As shown in the appendix Figure 4 shows the relationship between the group delays corresponding to each phase value. According to the above analysis, by subtracting the value after removing the linear delay D extra -P - δ DUT , and then averaging it, the fixed phase deviation value between the phase compensated by the all-pass filter and the actual phase characteristic of the system under test can be obtained, that is:

[0096]

[0097] S50: Based on the fixed phase deviation value, construct a fixed phase compensation module based on the FFT-IFFT filtering form.

[0098] S60: Cascade the IIR all-pass phase-frequency compensation filter and the fixed phase compensation module to obtain a broadband phase-frequency compensation filter.

[0099] In the specific implementation process, since the main purpose of the all-pass filter is to compensate for the group delay of the system, according to the group delay calculation formula, a fixed phase value such as (12) that does not change with frequency will be eliminated due to the differential subtraction during the group delay formula calculation, ultimately resulting in the all-pass filter being unable to capture this fixed phase value and perform compensation. For this reason, the system can compensate for the fixed phase value for each frequency point through a cascaded FFT-IFFT filtering form. At the same time, to solve problems such as the complex operations brought by large-point Fourier transforms and the spectrum leakage caused by non-integer multiple periods, the system logic for implementing fixed phase value compensation in the frequency domain based on the overlapping frame concept. By introducing multiple additional and identical filtering modules and dividing a large segment of data into several small segments as required, each module filters the data frames at different starting positions. Since there is an overlapping part in the data frames processed by each filtering module, the system selects the data frames processed by different modules according to certain rules, thereby finally obtaining filtered data without spectrum leakage and with a controllable amount of calculation. Finally, cascade the constructed IIR all-pass phase-frequency compensation filter and the fixed phase compensation module into the broadband phase-frequency compensation filter as shown in the appendix Figure 1 shown.

[0100] The beneficial effects of this embodiment can refer to the foregoing embodiments and will not be elaborated here. Referring to the appendix Figure 5 , based on the same inventive concept as in the foregoing embodiments, the embodiments of the present application also provide a broadband phase-frequency compensation method, which uses the broadband phase-frequency compensation filter provided by the embodiments of the present application and includes the following steps:

[0101] S70: Obtain the original signal.

[0102] S80: Input the original signal into the broadband phase-frequency compensation filter to obtain the target signal.

[0103] In the specific implementation process, as shown in the appendix Figure 1 shown, the original signal is the signal to be calibrated and compensated. Input the calibration signal into the filter. First, compensate through the IIR all-pass phase-frequency compensation filter, and then compensate through the fixed phase compensation module. Finally, the calibrated signal is output to obtain a signal with the phase information completely compensated. That is: input the original signal into the broadband phase-frequency compensation filter to obtain the target signal, including:

[0104] Input the original signal into the IIR all-pass phase-frequency compensation filter of the broadband phase-frequency compensation filter for one-time compensation to obtain the first output signal;

[0105] Input the first output signal into the fixed phase compensation module of the broadband phase-frequency compensation filter for secondary compensation to obtain the target signal.

[0106] Execute the foregoing steps through a system group delay estimation module, an IIR all-pass phase-frequency compensation filter coefficient generation module, a fixed phase offset value calculation module, and an FFT-IFFT based fixed phase compensation module to estimate the phase characteristics of each frequency point of the system, calculate the group delay of the system, and generate the all-pass filter coefficients to infer the fixed phase offset information of the system. Then, use the FFT-IFFT operation to perform conventional IIR phase compensation and fixed phase offset compensation on the system, so as to achieve the purpose of finally correcting the system phase without distortion.

[0107] In one embodiment, after the original signal is input into the IIR all-pass phase-frequency compensation filter of the broadband phase-frequency compensation filter for one-time compensation to obtain the first output signal, the compensation method further includes:

[0108] Obtain the positive and negative signs of the zero-frequency signal according to the state of the fixed phase deviation value.

[0109] In the specific implementation process, in order not to change the magnitude of the DC signal, this application will not perform fixed phase compensation operation on the zero-frequency signal, but its sign should change with the sign of the result after multiplying other frequency points by the fixed phase value. Otherwise, due to the introduction of overlapping frames, there will be a fault phenomenon in the compensated signal. To achieve the above operation, as shown in the appendix Figure 6 First, assume that the output of the IIR all-pass filter compensated time-domain signal is y(n). Perform FFT Fourier transform on y(n) to obtain the signal Y(jω). At the same time, multiply it by the fixed phase deviation in the frequency domain. Then, judge whether the fixed phase compensation value will change the sign of the multiplied frequency-domain signal Y'(jω), that is, judge whether is less than zero. If it changes, that is, less than zero, the sign of the zero-frequency signal Y′(0) needs to be changed at the same time. After frequency-domain compensation, the signal will be subjected to IFFT Fourier inverse transform to restore the time-domain signal. The finally obtained z(n) is the calibrated and compensated data, that is, the target signal. As shown in the appendix Figure 9 is a comparison diagram of the signal before and after the zero-frequency signal is processed by the broadband phase-frequency compensation method provided by this embodiment of the application. The signal fault phenomenon is solved, so as to completely restore the compensated signal.

[0110] Based on the foregoing steps, input the first output signal into the fixed phase compensation module of the broadband phase-frequency compensation filter for secondary compensation to obtain the target signal, including:

[0111] Input the first output signal into the fixed phase compensation module of the broadband phase-frequency compensation filter for secondary compensation, and obtain the target signal based on the positive and negative signs of the zero-frequency signal.

[0112] Refer to the appendix Figure 7, when testing the broadband phase-frequency compensation method provided by the embodiments of the present application, it is a comparison schematic diagram of the misaligned time-domain signal and the aligned time-domain signal. Compared with the traditional frequency-domain signal alignment method, the time-domain signal alignment method based on peak search applied by the present application when calculating the system group delay has better data alignment accuracy in signals with waveform distortion caused by harmonic components. Based on the narrow pulse fast edge signal generator, the fast edge signal is collected multiple times. The upper subgraph is the misaligned single-cycle narrow pulse time-domain signal, and its signal fluctuation range is about 10 sampling points. After the time-domain waveform alignment is performed by the time-domain waveform alignment algorithm of the present application, the signal fluctuation in the lower subgraph drops to about 3 sampling points. This fluctuation is mostly caused by noise, and the noise can be weakened after averaging the signal, so that the phase-frequency characteristics of the system can be accurately extracted.

[0113] Refer to the appendix Figure 8 , it is a comparison schematic diagram of the uncompensated original signal, the signal compensated by the traditional IIR all-pass filter, and the signal compensated by the broadband phase-frequency compensation method provided by the embodiments of the present application. The upper subgraph is the original square wave signal without phase compensation, and this signal has serious phase distortion. The middle subgraph is the signal after being compensated by the traditional IIR all-pass filter, and the signal distortion degree has not been improved. The lower subgraph is the signal after being compensated by the cascaded IIR all-pass filter and the fixed phase value compensation design of the present application, and its signal distortion has been greatly improved, thereby proving the effectiveness of the compensation method of the present application. It should be noted that the design concept of the traditional IIR all-pass filter is group delay compensation, and due to its own characteristics, it cannot compensate for the fixed phase value introduced by the hardware defects of the system itself. Therefore, it is necessary to cascade the FFT-IFFT module provided by the present application for the complete phase compensation of the system.

[0114] Refer to the appendix Figure 10 , based on the same inventive concept as in the foregoing embodiments, the embodiments of the present application further provide a device for constructing a broadband phase-frequency compensation filter, including:

[0115] A group delay estimation module, configured to obtain a group delay estimation value of the system to be measured according to the phase estimation value of the system to be measured;

[0116] A first construction module, configured to obtain IIR all-pass phase-frequency compensation filter coefficients and construct an IIR all-pass phase-frequency compensation filter according to the group delay estimation value;

[0117] A phase compensation obtaining module, configured to obtain a phase compensation value according to the pole distribution of the IIR all-pass phase-frequency compensation filter;

[0118] A fixed phase deviation obtaining module, configured to obtain a fixed phase deviation value according to the actual phase value and the phase compensation value of the system to be measured;

[0119] A second construction module, configured to construct a fixed-phase compensation module in the form of FFT-IFFT filtering based on a fixed phase deviation value;

[0120] A target construction module, configured to cascade an IIR all-pass phase-frequency compensation filter and the fixed-phase compensation module to obtain a broadband phase-frequency compensation filter.

[0121] Refer to Appendix Figure 11 , based on the same inventive concept as in the foregoing embodiments, an embodiment of the present application further provides a broadband phase-frequency compensation device, including:

[0122] An acquisition module, configured to acquire an original signal;

[0123] A compensation module, configured to input the original signal into the broadband phase-frequency compensation filter to obtain a target signal.

[0124] Those skilled in the art should understand that the division of each module in the embodiment is only a division of logical functions. In actual application, all or part of them can be integrated into one or more actual carriers, and these modules can all be implemented in the form of software called by a processing unit, or all be implemented in the form of hardware, or be implemented in a form combining software and hardware. It should be noted that the construction device of the broadband phase-frequency compensation filter and each module in the broadband phase-frequency compensation device in this embodiment correspond one by one to each step in the construction method and the broadband phase-frequency compensation method of the broadband phase-frequency compensation filter in the foregoing embodiments. Therefore, the specific implementation manners of this embodiment can refer to the foregoing implementation manners and will not be elaborated here.

[0125] Based on the same inventive concept as in the foregoing embodiments, an embodiment of the present application further provides a computer-readable storage medium, storing a computer program, which when loaded and executed by a processor, implements the construction method of the broadband phase-frequency compensation filter or the broadband phase-frequency compensation method provided by the embodiment of the present application.

[0126] Based on the same inventive concept as in the foregoing embodiments, an embodiment of the present application further provides an electronic device, including a processor and a memory, wherein,

[0127] The memory is used to store a computer program;

[0128] The processor is used to load and execute the computer program so that the electronic device executes the construction method of the broadband phase-frequency compensation filter or the broadband phase-frequency compensation method provided by the embodiment of the present application.

[0129] In some embodiments, the computer-readable storage medium may be a memory such as FRAM, ROM, PROM, EPROM, EEPROM, flash memory, magnetic surface memory, optical disc, or CD-ROM; or may be various devices including one or any combination of the above memories. The computer may be various computing devices including smart terminals and servers.

[0130] In some embodiments, the executable instructions may be in the form of a program, software, software module, script, or code, and may be written in any form of programming language (including compiled or interpreted languages, or declarative or procedural languages), and may be deployed in any form, including being deployed as an independent program or being deployed as a module, component, subroutine, or other unit suitable for use in a computing environment.

[0131] As an example, the executable instructions may or may not correspond to a file in the file system, may be stored as part of a file that stores other programs or data, for example, in one or more scripts in a Hyper Text Markup Language (HTML) document, stored in a single file dedicated to the program being discussed, or stored in multiple cooperating files (for example, files that store one or more modules, subroutines, or portions of code).

[0132] As an example, the executable instructions may be deployed to execute on one computing device, or on multiple computing devices located at one location, or on multiple computing devices distributed at multiple locations and interconnected by a communication network.

[0133] It should be noted that in this document, the term "comprising", "including" or any other variant thereof is intended to cover a non-exclusive inclusion, such that a process, method, article or system comprising a series of elements includes not only those elements but also other elements not expressly listed, or also includes elements inherent to such process, method, article or system. Without further limitation, an element defined by the statement "comprising a..." does not exclude the existence of additional identical elements in the process, method, article or system comprising such element.

[0134] The serial numbers of the embodiments of the present application above are only for description and do not represent the superiority or inferiority of the embodiments.

[0135] Through the description of the above embodiments, those skilled in the art can clearly understand that the above-described example methods can be implemented by means of software plus a necessary general hardware platform. Of course, they can also be implemented by hardware, but in many cases, the former is a better implementation. Based on such an understanding, the technical solution of the present application, in essence, or the part that contributes to the prior art can be embodied in the form of a software product. This computer software product is stored in a storage medium (such as read-only memory / random access memory, magnetic disk, optical disc), and includes several instructions to enable a multimedia terminal device (which can be a mobile phone, computer, television receiver, or network device, etc.) to execute the methods described in various embodiments of the present application.

[0136] In summary, a broadband phase-frequency compensation filter provided by the present application, its construction method, broadband phase-frequency compensation method, medium and device are composed of a cascaded IIR all-pass phase-frequency compensation filter and a fixed phase compensation module to form a broadband phase-frequency compensation filter. After the signal is compensated by the IIR all-pass phase-frequency compensation filter, the fixed phase compensation module compensates for the fixed phase deviation value between the phase compensated by the IIR all-pass phase-frequency compensation filter and the actual phase characteristic of the system to be measured. The fixed phase compensation module in the form of FFT-IFFT filtering compensates for the fixed phase value at each frequency point, making up for the deficiency brought by the traditional all-pass filter design that cannot capture the fixed phase of all frequency points due to the calculation of group delay, thereby realizing the complete compensation of the phase information of the acquisition system.

[0137] The above are only the preferred embodiments of the present application and are not intended to limit the present application. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A broadband phase-frequency compensation filter, characterized in that Comprising: A cascaded IIR all-pass phase-frequency compensation filter and a fixed phase compensation module, wherein the fixed phase compensation module is constructed based on the FFT-IFFT filtering form, and the fixed phase compensation module is used to compensate for the fixed phase deviation value between the phase compensated by the IIR all-pass phase-frequency compensation filter and the actual phase characteristic of the system under test. The fixed phase deviation value does not change with frequency and is obtained according to the actual phase value and the phase compensation value of the system under test. The phase compensation value is obtained according to the pole distribution of the IIR all-pass phase-frequency compensation filter. The IIR all-pass phase-frequency compensation filter obtains the IIR all-pass phase-frequency compensation filter coefficients and is constructed according to the group delay estimation value of the system under test, and the group delay estimation value is obtained according to the phase estimation value of the system under test.

2. A construction method of a broadband phase-frequency compensation filter, characterized in that, The method for constructing a broadband phase-frequency compensation filter as claimed in claim 1, comprising the following steps: According to the phase estimation value of the system under test, obtain the group delay estimation value of the system under test; According to the group delay estimation value, obtain the IIR all-pass phase-frequency compensation filter coefficients and construct an IIR all-pass phase-frequency compensation filter; According to the pole distribution of the IIR all-pass phase-frequency compensation filter, obtain the phase compensation value; According to the actual phase value of the system under test and the phase compensation value, obtain the fixed phase deviation value; Based on the fixed phase deviation value, construct a fixed phase compensation module based on the FFT-IFFT filtering form; Cascade the IIR all-pass phase-frequency compensation filter and the fixed phase compensation module to obtain a broadband phase-frequency compensation filter.

3. The construction method of the broadband phase-frequency compensation filter according to claim 2, characterized in that, Before obtaining the group delay estimation value of the system under test according to the phase estimation value of the system under test, the construction method further includes: According to the target phase value and the phase-frequency response of the system under test, obtain the phase estimation value of the system under test; wherein the target phase value is the phase value of the digital angular frequency after the Fourier transform of the time-domain average data.

4. The construction method of the broadband phase-frequency compensation filter according to claim 3, characterized in that Before obtaining the phase estimation value of the system under test according to the target phase value and the phase-frequency response of the system under test, the construction method further includes: Perform average denoising processing on the time-domain signal to obtain the time-domain average data.

5. The method for constructing a broadband phase-frequency compensation filter according to claim 4, wherein Before performing average denoising processing on the time-domain signal to obtain the time-domain average data, the construction method further includes: Perform data alignment on the acquired data based on a data alignment algorithm for peak search to obtain the time-domain signal.

6. A broadband phase-frequency compensation method, characterized in that, The method of using a broadband phase-frequency compensation filter as claimed in claim 1, comprising the following steps: Obtain an original signal; Input the original signal into the broadband phase-frequency compensation filter to obtain a target signal.

7. The broadband phase-frequency compensation method according to claim 6, wherein The step of inputting the original signal into the broadband phase-frequency compensation filter to obtain a target signal includes: Input the original signal into the IIR all-pass phase-frequency compensation filter of the broadband phase-frequency compensation filter for primary compensation to obtain a first output signal; Input the first output signal into the fixed phase compensation module of the broadband phase-frequency compensation filter for secondary compensation to obtain a target signal.

8. The broadband phase-frequency compensation method according to claim 7, wherein After the original signal is input into the IIR all-pass phase-frequency compensation filter of the broadband phase-frequency compensation filter for primary compensation to obtain a first output signal, the compensation method further includes: Obtaining the positive or negative sign condition of the zero-frequency signal according to the state of the fixed phase deviation value; The step of inputting the first output signal into the fixed phase compensation module of the broadband phase-frequency compensation filter for secondary compensation to obtain a target signal includes: Inputting the first output signal into the fixed phase compensation module of the broadband phase-frequency compensation filter for secondary compensation, and obtaining a target signal based on the positive or negative sign condition of the zero-frequency signal.

9. A computer-readable storage medium storing a computer program, characterized in that, When the computer program is loaded and executed by a processor, it implements the method for constructing a broadband phase-frequency compensation filter according to any one of claims 2-5 or the broadband phase-frequency compensation method according to any one of claims 6-8.

10. An electronic device, characterized in that, Comprising a processor and a memory, wherein, The memory is used for storing a computer program; The processor is used for loading and executing the computer program, so that the electronic device executes the method for constructing a broadband phase-frequency compensation filter according to any one of claims 2-5 or the broadband phase-frequency compensation method according to any one of claims 6-8.

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