CN115510786A - A frequency solution method and system for high dynamic shock signals - Google Patents

Abstract

The invention provides a frequency calculation method and a frequency calculation system for a high dynamic impact signal. The system comprises a frequency mixing module, a signal acquisition module and a frequency resolving module. The circuit parameters of the frequency mixing module, such as the number of channels, a filter, a local oscillator signal and the like, are determined by simulation optimization; when in measurement, signals enter a plurality of channels simultaneously after being input into a frequency mixing module, each channel has different signal frequency bands, and the signals of the channels are converted into difference frequency signals of a low frequency band; the difference frequency signal is input into a signal acquisition module after being filtered, and measurement data of different signal frequency bands are obtained; and the frequency calculating module is used for solving the instantaneous frequency of the signal according to the frequency spectrum parameters and the measurement data of multiple channels, so that the impact speed is obtained. The invention has the characteristics that the requirements on the sampling rate and the circuit manufacture are reduced by utilizing multi-channel mixing, the frequency calculation of high dynamic signals can be realized, and the invention has important application prospect in the field of high dynamic impact signal measurement.

Description

A frequency solution method and system for high dynamic shock signals

technical field

The invention relates to a method and system for calculating the frequency of a high dynamic impact signal, which is used for calculating the frequency of a high dynamic impact signal generated by laser interferometry, and belongs to the field of high dynamic signal measurement.

Background technique

With the trend of informatization, digitization, and intelligence in the military field, the development of various penetrating weapons is in full swing. In the process of weapon equipment development, the intelligent sensing system and missile-borne instruments carried by it need to be verified by experiments in strong impact environments. , so the measurement of various parameters of the projectile is becoming more and more important. By obtaining the speed of the projectile when it exits the chamber, flies, hits the target, etc., it can be analyzed in detail about its exit and flight status. In the test, the instantaneous speed may reach or exceed 200m/s. For such speed measurement, there are many methods that can be realized. The most typical method is the time interval measurement method, but the average speed is obtained. The information is limited and cannot be used to study the entire impact movement process. At present, the measurement speed can be divided into two categories according to the measurement method: contact type and non-contact type. Contact measurement mainly refers to the on-off target, which is when the projectile passes through the contact with the target surface, and the pulse electrical signal is generated by the circuit opening or closing in the device, and the pulse electrical signal is used as the target for opening or closing the chronograph. Signal. The advantages of the contact measurement method are simple structure, convenient manufacture and strong anti-interference ability, etc., so it is widely used in the early projectile velocity measurement. But at the same time, this method is also accompanied by its own inherent defects, that is, it affects the flight trajectory. In contrast, non-contact measurement has been widely used due to its advantages such as almost no impact on ballistics and non-destructive experiments.

The transient high-speed laser velocity measurement technology based on laser interferometry has the advantages of high measurement accuracy, wide velocity range, and fast dynamic response. In the shock measurement process, the principle of laser Doppler is adopted, and the diffraction grating is used as the cooperative target, so the Doppler frequency shift generated by the grating movement is correlated with the shock velocity. In 2014, Zhang et al. "The technology of grating Laser Doppler Velocimeter" (The technology of grating Laser Doppler Velocimeter) in Volume 9297 of "International Symposium on Optoelectronic Technology and Application" (International Symposium on Optoelectronic Technology and Application) For measuring transverse velocity of objects) a grating Doppler detection system is designed, which uses a differential measurement method for measurement. After the two beams of diffracted light from the grating are mixed, the detector detects the beat frequency when the grating moves. In 2020, Ren Yuan and others applied for the Chinese patent "A Method for Measuring the Velocity of Objects Based on the Doppler Effect of Polarization Gratings" (Patent No.: 202011457850.6) and proposed to superimpose the ±1st-order diffracted light of the polarization grating to obtain a beat frequency characteristic Using the method of linearly polarized light, and using the short-time Fourier transform to analyze the time-frequency of the signal, the characteristics of the speed of motion with time are obtained. Therefore, how to obtain the Doppler frequency shift signal accurately and rapidly in real time is particularly necessary. The high dynamic impact signal has many unique characteristics: the entire impact process is very short, on the order of milliseconds, and the signal is dynamically changing, the dynamic range of the frequency is large, and the bandwidth is relatively narrow for a certain moment. For the signal to be tested, the signal frequency can be as high as hundreds of megahertz, which requires a high sampling rate during acquisition, and there will be a large amount of data during transmission and processing, which leads to real-time sampling and processing of the signal. Handling is relatively difficult.

In recent years, there have been descriptions of related technologies at home and abroad for measuring devices and methods for high dynamic shock signals. In 2015, Wang Qiang and others from Anhui Institute of Metrology applied for a Chinese patent "a new method for testing or calibrating impact velocity using an impact velocity measurement device" (patent number: 201510915520.X), which proposed a signal receiving antenna, a spectrum processing module and The impact velocity measurement device of the signal processing module adopts a high-gain receiving antenna and a pulse width capture method and a pulse width capture module with a main frequency of up to 150MHz for collection, thereby realizing high-precision velocity measurement. In 2021, Wu Yongzheng and others applied for the Chinese patent "Substation and Acquisition Method for Rock Burst Data Acquisition" (patent number: 202111403425.3) and proposed to store data according to the acquisition frequency of the first and second frequencies according to the signal strength, thereby reducing data storage Quantitative method. In 2019, Lu Guohui of Heilongjiang University and others applied for the Chinese patent "A high-speed and high-frequency shock wave overpressure data acquisition device and acquisition method" (Patent No.: 201910065953.9), which proposed a signal acquisition module, an optical trigger module, a long-distance transmission module, and a data storage module. And the data acquisition device of the control module. In 2019, Xu Cheng and others applied for the Chinese patent "A Shock Wave Pressure Acquisition Device" (patent number: 201920833433.3) and proposed a high-speed and high-frequency shock wave overpressure data acquisition device and acquisition method, which can be triggered by optical signals to achieve data acquisition. , long-distance transmission and storage, etc. The introduction of these methods has largely promoted the development of shock signal sampling technology. However, due to the high-frequency characteristics of shock signals, the realization of real-time sampling and data transmission has relatively high requirements for the acquisition system.

High dynamic shock signals have the characteristics of high frequency, and therefore have high requirements on the sampling rate of data acquisition. There are currently many measurement methods for signals of this nature. In 2014, Damilola et al. published the paper "Compressed sensing techniques for receiver based post-compensation of transmitter's nonlinear distortions in OFDM" on page 282 of Volume 97 of "Signal Processing" Systems) proposed to use compressive sensing technology to compensate the amplifier. In 2021, Yamamoto et al. published the paper "Metal Ratio Isochronous Sampling: A Efficient Waveform Acquisition Method" (Metallic RatioEquivalent-Time Sampling: A Highly Efficient Waveform Acquisition Method) proposes to set the signal frequency and sampling frequency of the input signal to the metal ratio when using equivalent sampling for waveform acquisition. In 2012, Li Mei from Anhui University of Science and Technology applied for a Chinese patent "Partial discharge signal acquisition device based on frequency mixing technology" (patent number: 201220049848.X). The application of frequency mixing technology reduces the frequency of the partial discharge UHF signal and retains the frequency of the signal. Peak and phase characteristics, thus solving the core problem in transformer partial discharge UHF detection. In 2017, Liu Lianxi from Xidian University and others applied for the Chinese patent "Variable Gain Mixer Amplifier, Biological Signal Acquisition and Processing Chip and System" (Patent No.: 201710375510.0) using a variable gain mixer amplifier to receive biological signals and local oscillators signal, and output the modulated audio signal. These methods effectively reduce the frequency of high-frequency signals, thereby reducing the difficulty of sampling and data transmission of signals. However, when sampling and solving the high dynamic impact signal, there is still a lack of methods for down-frequency processing and sampling of the signal and for storing, transmitting and solving the measurement data.

Based on the above background, the present invention proposes a method and system for calculating the frequency of high dynamic shock signals to solve the above-mentioned problem of acquisition and processing of high frequency shock signals whose frequencies are constantly changing dynamically. It is mainly divided into three steps. The first step is to determine the circuit design scheme of the acquisition system according to the frequency range of the signal to be tested. The signal to be tested enters multiple channels and mixes with different local oscillator signals, so as to realize the frequency reduction of the dynamically transformed signal. , so the optimal number of channels can be selected first through simulation to ensure the effective reduction of signal frequency, as well as the control of circuit cost and data acquisition and processing difficulty. The second step is that the Doppler frequency shift signal generated by the impact of the projectile enters the actual multiple acquisition channels after being filtered in different frequency ranges, and is mixed with the local oscillator signal of each channel to obtain a low-frequency difference frequency signal. After the signal is filtered, amplified, etc., it is converted into a digital signal by the analog-to-digital conversion chip, and then transmitted to the FPGA for storage and transmission. The third step is to restore and process the collected signals, compensate the signals according to the simulation results, filter and combine the collected data of multiple channels, restore the entire impact process collected, and use the Hilbert-Huang transform to obtain The signal frequency is used to calculate the impact velocity of the projectile according to the relevant principles of Doppler frequency shift.

The key point of the present invention is that, according to the characteristics of the signal to be tested, the acquisition quality of the signal under different conditions is first simulated by means of simulation, and the circuit cost and the difficulty of data storage and transmission are comprehensively considered to determine the optimal acquisition scheme, including the number of channels , filter parameters, local oscillator signal frequency and other circuit parameters; multi-channel mixing is performed on the high dynamic impact signal before acquisition, and the frequency of the signal to be tested is reduced to solve the problem of difficult sampling and transmission of high-frequency signals. The advantage of the present invention is that, by performing frequency mixing processing on electrical signals to reduce the signal sampling rate, not only can effectively reduce the amount of data that needs to be stored and transmitted, but also reduce the requirements for analog circuit design; Dynamic characteristics, multi-channel parallel circuits can be sampled at the same time, avoiding the problem that a single channel cannot be captured due to the short impact signal time; the corresponding number of channels and local oscillator signals can be designed for signals with different frequency ranges, expanding the scope of application of this method .

To sum up, the method and system for calculating the frequency of a high dynamic impact signal proposed by the present invention, on the basis of the traditional sampling of the signal, adds multi-channel mixing processing to the analog circuit part, reducing the signal frequency , and can capture the impact signal in real time, which effectively reduces the subsequent requirements for signal acquisition and the amount of data that needs to be stored and transmitted; and for impact signals with different characteristics, the optimal design scheme of the down-frequency circuit part can be determined through simulation, and the number of channels can be adjusted. And local oscillator signal frequency, it has good applicability to the frequency solution and processing of high dynamic impact signal.

Contents of the invention

(1) Technical problems to be solved

The purpose of the present invention is to provide a method and system for calculating the frequency of high dynamic impact signals, which are used to solve the acquisition problem of fast-changing high-frequency dynamic signals. The multi-channel frequency mixing part at the front end of the acquisition circuit can perform preliminary Processing, to obtain a lower frequency difference frequency signal, while effectively reducing the signal sampling rate, it also reduces the difficulty of circuit design, data storage and transmission, and has broad application prospects.

(2) Technical solution

The present invention, that is, a method and system for calculating the frequency of a high dynamic impact signal, comprises the following steps:

Step 1. According to the frequency range and change speed of the signal to be tested under different conditions, determine the optimal design scheme of the down-frequency circuit part through simulation. To simulate the signal to be tested,

分别随着时间t变化，频率范围是ω₀＜ω_t≤ω_max，Among them, the signal amplitude A _t , frequency ω _t and phase

change with time t respectively, the frequency range is ω ₀ <ω _t ≤ω _max ,

M＝ω _max -ω ₀ (2)

内最小整数，每个通道的可通过频率为，That is, M is the frequency bandwidth of the entire process of the signal. If the frequency bandwidth of the signal that each channel can pass through during the frequency reduction process is m, the number of channels n is selected to be greater than

The smallest integer in , the permissible frequency of each channel is,

In order to avoid the lack of collection of boundary frequency signals, the signal frequency ranges that two adjacent channels can pass overlap. In order to simulate a variety of experimental environments and ensure the accuracy of the results, random noise of different sizes was added to the original signal, and the experiment was repeated. Comparing the accuracy of simulation results and the size of resource consumption when changing the bandwidth m of each channel, determine the optimal circuit design scheme.

Step 2: The signal to be tested is input into n channels at the same time, and the band-pass filters at the front end of different channels will retain different signal frequencies, and then the filtered signal is mixed with the local oscillator signal. If the signal at a certain moment is,

Then, for this moment, after the signal with the frequency ω _t is band-pass filtered, the signals with at most two channels are retained, and the subsequent mixing process is continued. Among them, the filtering range of the front-end bandpass filter of the kth channel is,

ω _k ≤ω≤ω _k +m (5)

Assuming that the channel signal is reserved, the local oscillator signal in the mixing module is,

f _k (t)＝A _k cos(ω _k t) (6)

The signal to be tested and the local oscillator signal are input to the mixer at the same time. Due to the nonlinear characteristics of the current and voltage in the mixer circuit, the output signal includes the sum frequency, difference frequency and higher harmonic components of the two inputs. According to the signal to be tested and the local oscillator signal represented by formula (4) and formula (6), then the output signal is,

After the output signal passes through a low-pass filter or a suitable frequency selection network, the signal component with frequency ω _t -ω _k is retained.

Step 3. The actual high dynamic impact signal can be generated by the impact machine, and the signal to be tested is input to the actual down-frequency circuit. After band-pass filtering, frequency mixing and frequency selection, the remaining low-frequency signal components are dynamically filtered and processed by the operational amplifier. Impedance matching, and then through the single-ended to differential chip, the generated differential analog signal is sampled with an analog-to-digital converter, and the collected results are stored in DDR3. The entire acquisition process and subsequent data storage and uploading are controlled by the host computer through the USB communication module, and the data is finally transmitted using Ethernet.

Step 4: Process the collected data. First restore the entire impact process. Due to the multi-channel parallel frequency reduction acquisition mode, there are 1 or 2 channels output at any time. When the signal frequency is within the cross range of the two channels, there are two channels that can collect signals. For For this part of the sampling results, only one signal needs to be reserved for analysis. In the simulation of the signal and the actual circuit test, compare the absolute frequency error Δ of the two channels under the same input signal,

Δ＝ω _re -ω _th (8)

Record the channel with a smaller absolute error Δ, and keep the channel signal when recovering, so as to recover the frequency of the collected signal during the entire dynamic impact process; secondly, perform Hilbert-Huang transform on the synthesized signal to solve the instantaneous frequency of the signal, Empirical mode decomposition decomposes the collected non-stationary time-varying signal into eigenmode functions,

Among them, c _i (t) is the decomposed N eigenmode functions, and r _N (t) is the residual signal. Since the high dynamic impact signal to be measured is a narrowband signal, there is a decomposition result with an amplitude obviously larger than The components of other eigenmode functions, which contain most of the information of the signal to be measured, can be used to obtain the instantaneous frequency of the signal by performing Hilbert transform on this component. Assuming that the dth component is the target component, then for c _d (t) undergoes Hilbert transform, and its analytic function can be obtained,

Y(t)=c _d (t)+jH[c _d (t)]=a(t)e ^jθ(t) (10)

是信号的瞬时幅值，

是信号的瞬时相位，所以信号的瞬时频率可以通过对瞬时相位求导进行求解，In the formula,

is the instantaneous amplitude of the signal,

is the instantaneous phase of the signal, so the instantaneous frequency of the signal can be solved by deriving the instantaneous phase,

Finally, the actual frequency of the signal to be tested is obtained by combining the local oscillator signal. According to the principle of frequency mixing, if the calculated frequency of the k-channel signal is ω _d (t), the actual frequency is,

ω _re = ω _d (t) + ω _k (12)

Thereby, the measurement of high dynamic shock signal frequency is realized.

(3) Beneficial effects

The beneficial effect of the present invention is that the number of channels input during measurement and the frequency of the local oscillator signal are determined according to the actual signal to be measured by means of simulation to ensure the balance of difficulty and cost in signal acquisition; The design of filter parameters, etc., is convenient for the integrity of subsequent data restoration; the signal is mixed to reduce the high-frequency signal to a relatively low frequency. Compared with the traditional direct collection method, the sampling rate is effectively reduced. Compared with the original high-frequency signal, it not only reduces the design requirements of the circuit, but also greatly reduces the amount of data, which is convenient for subsequent storage and transmission; the parallel method is adopted, and the signal is input into multiple channels at the same time, which avoids the short signal time Unable to capture, the real-time sampling of the impact signal is realized; due to the narrow-band characteristics of the signal, the Hilbert-Huang transform is used to solve the signal, and the impact velocity of the projectile is obtained through the frequency of the signal; according to the actual signal frequency and test range Needs, custom-made appropriate multi-channel mixing circuit, has good robustness and stability, and has broad application prospects.

Description of drawings

Accompanying drawing 1 is the flow chart of the frequency solution method of the high dynamic impact signal.

Accompanying drawing 2 is a typical structural diagram of the frequency solution system of the high dynamic impact signal.

Among them, 101 is a bandpass filter, 102 is a frequency reduction module; the acquisition module includes 103 an analog-to-digital conversion module, 104 a DDR3 storage module, 105 a USB communication module, 106 an Ethernet transmission module, 107 a computer, and 108 a frequency calculation module.

Accompanying drawing 3 is the collected high dynamic impact signal.

Accompanying drawing 4 is the empirical mode decomposition result of the maximum impact velocity signal.

Figure 5 is the instantaneous frequency corresponding to the maximum speed.

detailed description

Below in conjunction with example the present invention will be further described. Referring to accompanying drawing 1 is a flow chart of a method for calculating the frequency of a high dynamic impact signal, referring to accompanying drawing 2 is a typical structural diagram of the system. The operation steps combined with an example are as follows:

Step 1. The Doppler frequency shift signal generated by grating diffraction can reach a frequency of up to 90MHz after being converted into an electrical signal. During the simulation process, the original signal is designed as,

x ₀ ＝sin[2π(20×10 ³ +0.5×10 ¹¹ t)t] (1)

Add random noise with a mean value of 0 and a variance of 0.15, 0.25, and 0.35 to the original signal. By comparing the frequency error between the collected signal and the original signal, the number of channels is determined to be 6. After simulating different filter types and orders, it is finally determined that the passable frequency range of each channel is 0-20MHz, 15-35MHz, 30-50MHz, 45-65MHz, 60-80MHz and 75-95MHz, and the filter types are Chebyshev 24th order filter.

Step 2. The signal to be tested is first input into 6 channels at the same time, and the signal of a specific frequency band is selected by using the 101 band-pass filter, and then input into the frequency reduction module of 102 for preliminary processing, and its frequency is reduced, and then passed to the 103 analog-to-digital conversion module for The signal is pre-processed and sampled in real time, and the collected results can be stored in the 104DDR3 storage module. The process of collecting and data storage and uploading is controlled by the 107 computer through the 105USB communication module, and finally the stored collected data is uploaded through the 106 Ethernet transmission module to 107 computers to realize further calculation.

Step 3. The local oscillator signal in the frequency reduction process is generated by the on-chip DDS chip, which can ensure the miniaturization of the acquisition system. The chip is selected as AD9910, and the high-speed operational amplifier AD4857 is used to amplify the signal. The filtered signal to be tested and the local oscillator signal are input to the multiplier AD835 at the same time, and the difference frequency signal is retained by the low-pass filter LT6600 after operation. The filtered analog signal will pass through the single-ended to differential chip to adjust the bias level of the signal and suppress common-mode noise. Finally, a 16-bit dual-channel analog-to-digital converter AD9650 is used to sample the differential signal. This chip can achieve a sampling rate of 100MHz, and can effectively collect signals within 20MHz after frequency reduction. The collected digital signal is transmitted to 104DDR3 for storage, and can be transmitted to 107 computer via 106 Ethernet for storage. The acquisition process and the data storage and upload process can be controlled by the host computer, and the instructions are sent through the 105USB communication module.

Step 4: Calculate the collected data by the 108 frequency calculating module. First, the signal is restored to obtain a complete signal acquisition result. Then the Hilbert-Huang transform is performed on the data, and the signal is decomposed into multiple eigenmode functions by using the empirical mode decomposition; the Hilbert transform is performed on each component, and the instantaneous frequency is obtained by using the formula. Finally, according to the selected local oscillator signal and the principle of frequency mixing, the actual Doppler frequency shift signal frequency is calculated.

The above description of the present invention and its embodiments is not limited thereto, and what is shown in the drawings is only one of the embodiments of the present invention. Without departing from the inventive concept of the present invention, any structure or embodiment similar to the technical solution without creative design shall belong to the protection scope of the present invention.

Claims (3)

1. A frequency resolving method and a system of high dynamic impact signals are disclosed, the system comprises a frequency mixing module, a signal acquisition module and a frequency resolving module, and is characterized in that the channel number and the local oscillation signal frequency of a circuit to be detected in different frequency ranges are designed in a targeted manner, the frequency mixing processing is carried out on the signal to be detected in the acquisition process so as to reduce the frequency of a high-frequency signal, and therefore the system can acquire the signal at a lower sampling rate, and meanwhile, a plurality of channels are adopted to carry out parallel processing and sampling on the signal, so that the impact signal is captured; the signal is firstly divided into a plurality of different frequency bands by a multi-channel mixing mode and the frequency is reduced, then the difference frequency signal of the low frequency is reserved for the next step of collection and storage, and finally the instantaneous frequency is solved after the signal uploaded to the computer is synthesized and compensated.

2. The method and system according to claim 1, wherein the number of channels of the front-end down-conversion circuit and the local oscillation frequency of each channel are determined by simulation based on the actual signal to be measured, the original signal to be measured is simulated,

wherein the amplitude A of the signal _t Frequency omega _t And phase

Respectively, over time t, frequency range omega ₀ ＜ω _t ≤ω _max ，

M＝ω _max -ω ₀ (2)

That is, M is the frequency bandwidth of the signal in the whole impact process, the signal is simultaneously input into n channels, the front end of each channel is a passive band-pass filter, the pass-band ranges of the filters are different,

the frequency ranges of all channels are combined to cover the bandwidth of the signal to be measured, the passband frequency is gradually increased from the channel 1 to the channel n, and in order to avoid the problem that the signal of the frequency at the critical position cannot be collected, the frequency ranges which can be passed by two adjacent channels have certain overlap,

if the frequency bandwidth of the signal which can pass through each channel in the frequency reducing process is m, the number n of the channels is selected to be larger than m

Then the passable frequency for each channel is,

the signals screened by the band-pass filter are mixed with the local oscillator signals, the local oscillator signal frequency of each channel is different due to the difference of the pass band frequency of the band-pass filter and is set as the minimum value of the pass band frequency, and for the kth channel, the local oscillator signal frequency is omega _k If, at a certain moment, the signal of the k-channel is filtered by the band-pass filter, the k-channel signal can be represented as,

A′ _t is the amplitude of the signal after being attenuated by the filter, the local oscillator signal of the k channel is,

f _k (t)＝A _k cos(ω _k t) (7)

the band-pass filtered signal is mixed with the local oscillator signal, and due to the nonlinear characteristics of current and voltage in the mixer circuit, the output signal includes components of sum frequency, difference frequency, higher harmonic and the like of two inputs, so that the output signal is,

after the output signal passes through a low-pass filter, the frequency is kept to be omega _t -ω _k Signal division ofAnd thus the signal frequency is reduced, random noise is added to the simulated signal to be measured, so that the signal to be measured is,

wherein randn is random noise, b represents the variance of random noise, b, frequency bandwidth m and channel number n are changed, the deviation of the acquired signal frequency and a theoretical value is analyzed, taking k channel as an example, the frequency theoretical value is,

ω _th ＝ω _t -ω _k (10)

the frequency of the collected signal is omega _re Then the relative error is,

and selecting the result with the minimum error as the optimal design scheme by comparing the relative error.

3. The method and the system for resolving the frequency of the high dynamic impact signal according to claim 1, wherein the signal recovery and processing comprises the following steps:

firstly, the whole impact process is recovered, because of the working mode of multipath parallel frequency-reducing acquisition, 1 or 2 channels exist for output at any time, when the signal frequency is in the crossing range of two channels, two channels can acquire signals, therefore, the sampling result only needs to keep one signal for analysis, in the process of simulating the signal and testing the actual circuit, the absolute frequency error delta of the two channels under the same input signal is compared,

Δ＝ω _re -ω _th (12)

recording a channel with a smaller absolute error delta, and reserving a channel signal during recovery so as to recover the frequency of the acquired signal in the whole dynamic impact process;

secondly, the synthesized signal is subjected to Hilbert-Huang transform, the instantaneous frequency of the signal is solved, the acquired non-stationary time-varying signal is decomposed into an eigenmode function by empirical mode decomposition,

wherein, c _i (t) is the decomposed N eigenmode functions, r _N (t) is a residual signal, because the high dynamic impact signal to be measured is a narrow-band signal, a component exists in the decomposed eigenmode function and contains most frequency information of the signal to be measured, the instantaneous frequency of the signal can be obtained by performing Hilbert transform on the component, and if the d-th component is a target component, the instantaneous frequency of the signal is obtained by performing Hilbert transform on the d-th component _d (t) performing Hilbert transform to obtain an analytical function thereof,

Y(t)＝c _d (t)+jH[c _d (t)]＝a(t)e ^jθ(t) (14)

in the formula (I), the compound is shown in the specification,

is the instantaneous amplitude of the signal and,

is the instantaneous phase of the signal, the instantaneous frequency of the signal can be calculated by taking the derivative of the phase,

finally, the actual frequency of the signal to be measured is obtained by combining the local oscillator signal, and according to the frequency mixing principle, if the calculated k channel signal frequency is omega _d (t), then the actual frequency is,

ω _re ＝ω _d (t)+ω _k (16)

thereby realizing the measurement of the frequency of the high dynamic impact signal.

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