Equivalent time sampling method and system based on precision delay fine tuning and phase prediction

Abstract

The present application relates to the technical field of signal testing and measurement, and discloses an equivalent time sampling method and system based on precise delay fine tuning and phase prediction, which comprises the following steps: acquiring multiple alias sampling data of a measured signal by using a low sampling analog-digital converter, wherein the alias sampling data comprises multiple sampling point data of the same sampling period, and the initial sampling time of each alias sampling data is a continuous sampling time with the same preset delay; and reconstructing a waveform based on the multiple alias sampling data to obtain a complete period waveform of the measured signal. The present application uses a low-frequency alias signal generated by under-sampling as a phase reference, does not rely on the edge trigger of the measured signal, realizes the phase positioning of the sampling point through software prediction, is also applicable to signals without steep edges such as pure sine waves, avoids the negative impact of trigger jitter on precision, and uses a low sampling analog-digital converter to cooperate with precise delay to equivalently realize high-frequency sampling effect, thereby improving sampling precision while reducing hardware cost.

Description

Technical Field

[0001] This invention relates to the field of signal testing and measurement technology, specifically to an equivalent time sampling method and system based on precision delay fine-tuning and phase prediction. Background Technology

[0002] With the rapid development of electronic technology, the demand for measuring high-frequency and ultra-high-frequency signals is increasing. In fields such as radio frequency communication, radar systems, and high-speed digital circuits, engineers often need to observe and analyze periodic signal waveforms with frequencies as high as tens or even hundreds of GHz to evaluate signal quality, measure rise time, and analyze distortion.

[0003] Currently, time-domain observation of high-frequency signals mainly relies on high-end real-time oscilloscopes. According to the Nyquist sampling theorem, to accurately recover a signal waveform with frequency f, the sampling rate needs to be at least 2f. For a 56GHz signal, a sampling rate exceeding 112GSa / s is theoretically required. This places extremely high technical demands on analog-to-digital converter (ADC) hardware, resulting in very expensive equipment, and there is a physical upper limit to the sampling rate.

[0004] While the bandwidth and sampling rate of high-end real-time oscilloscopes have been increasing year by year, the cost has grown exponentially. Real-time sampling oscilloscopes in the hundreds of GHz range are not only extremely expensive, but their front-end analog bandwidth and ADC sampling rate also face technical bottlenecks in physical devices, making it difficult to improve them indefinitely.

[0005] Traditional equivalent time sampling techniques typically require a stable trigger signal to indicate the start position of each sampling period, making them unsuitable for measurement scenarios where an independent trigger signal cannot be provided, or where the trigger signal itself exhibits jitter. Furthermore, the equivalent resolution of equivalent time sampling directly depends on the accuracy of the delay step. High-precision adjustable delay circuits are costly to implement and susceptible to environmental factors such as temperature and voltage variations. Insufficient delay accuracy will lead to phase jitter or horizontal distortion in the reconstructed waveform, limiting its application. Summary of the Invention

[0006] This invention provides an equivalent time sampling method and system based on precise delay fine-tuning and phase prediction to solve the problems of high cost of detection equipment for ultra-high frequency periodic signals and low accuracy of traditional equivalent time sampling techniques. It is particularly suitable for application scenarios where the sampling rate is much lower than the frequency of the signal being measured, and can achieve accurate time-domain waveform reconstruction for various periodic signals such as sine waves, square waves, and triangular waves.

[0007] In a first aspect, the present invention provides an equivalent time sampling method based on precise delay fine-tuning and phase prediction, the method comprising: Using a low-sampling analog-to-digital converter, multiple aliased sampling data of the signal under test are acquired. The aliased sampling data includes multiple sampling point data with the same sampling period. The initial sampling time of each aliased sampling data is a continuous sampling time with the same preset delay. Waveform reconstruction is performed based on multiple aliased sampled data to obtain the complete periodic waveform of the measured signal.

[0008] The equivalent time sampling method based on precision delay fine-tuning and phase prediction provided by this invention uses the low-frequency aliasing signal generated by undersampling as a phase reference. It does not rely on the edge triggering of the measured signal and achieves phase positioning of the sampling point through software prediction. It is also applicable to signals without steep edges, such as pure sine waves, and avoids the negative impact of trigger jitter on accuracy. It uses a low-sampling analog-to-digital converter in conjunction with precision delay and equivalent to achieve high-frequency sampling effect, improving sampling accuracy while reducing hardware cost.

[0009] In one optional implementation, a low-sampling analog-to-digital converter is used to acquire multiple aliased sampled data of the signal under test, including: Set the initial sampling time for the first aliased sampling data, acquire multiple sampling point data according to the preset sampling period, and combine the multiple sampling point data into the first aliased sampling data according to the order of the sampling time; The initial sampling time of the first aliased sampled data is finely adjusted according to a preset delay to obtain the initial sampling time of the next aliased sampled data; Based on the initial sampling time of the next aliased sampling data, multiple sampling point data are acquired according to a preset sampling period, and the multiple sampling point data are combined into the next aliased sampling data according to the order of sampling time. Repeat the process of fine-tuning the initial sampling time of the next aliased sampling data according to the preset delay and acquiring multiple sampling point data to obtain multiple aliased sampling data.

[0010] The equivalent time sampling method based on precision delay fine-tuning and phase prediction provided by this invention can cover the entire phase range of the measured signal with a low-speed ADC by successively fine-tuning the initial sampling time and collecting multiple sets of mixed sampling data in batches, without the need for a matching trigger circuit. The waveform is reconstructed by phase sorting of multiple batches of sampling points, which greatly improves the time domain resolution, avoids the phase jitter distortion of traditional equivalent sampling, reduces the hardware bandwidth and sampling rate requirements, and effectively reduces the cost of measurement equipment.

[0011] In one optional implementation, the duration of the preset delay is determined based on the frequency of the signal under test and the target measurement accuracy, and the total duration of the preset delay for each aliased sample data covers at least one complete sampling cycle of the signal under test.

[0012] The equivalent time sampling method based on precision delay fine-tuning and phase prediction provided by this invention flexibly matches the preset delay according to the frequency of the signal under test and the required measurement accuracy. The higher the accuracy requirement, the smaller the delay step, balancing measurement resolution and acquisition efficiency. At the same time, the total delay is limited to cover the entire sampling period, ensuring that the sampling points fill the entire phase range of the signal, avoiding the loss of waveform reconstruction, and ensuring the complete and accurate restoration of the UHF signal waveform.

[0013] In one optional implementation, the larger the preset delay, the faster the measurement speed and the lower the waveform reconstruction accuracy. The smaller the preset delay, the slower the measurement speed, and the higher the waveform reconstruction accuracy.

[0014] The equivalent time sampling method based on precision delay fine-tuning and phase prediction provided by this invention clarifies the trade-off between preset delay and measurement performance: increasing the delay can reduce the number of sampling rounds and improve the measurement rate, but the sampling phase interval becomes wider, resulting in the loss of waveform details and a decrease in accuracy; reducing the delay can refine the phase sampling points and improve the waveform restoration accuracy, but it will increase the number of sampling rounds and lengthen the overall measurement time. The delay should be balanced as needed to adapt to different measurement speed and accuracy requirements.

[0015] In one optional implementation, the sampling point data is the voltage corresponding to the sampling point. Waveform reconstruction is performed based on multiple aliased sampling data to obtain the complete periodic waveform of the measured signal, including: Based on the sampling frequency of the low-sampling analog-to-digital converter and the frequency of the signal under test, the aliasing sampling period is determined using the Nyquist sampling theorem. Based on the aliasing sampling period and the total duration of multiple aliasing sampling data, calculate the sampling point phase of the measured signal corresponding to each sampling point; The phase-voltage sequence is obtained by sorting the sampling points from smallest to largest according to their phases and combining the corresponding sampling point data. Plot a scatter plot or line graph with phase as the horizontal axis and voltage as the vertical axis to obtain the complete periodic waveform of the measured signal.

[0016] The equivalent time sampling method based on precision delay fine-tuning and phase prediction provided by this invention calculates the aliasing period based on the Nyquist sampling theorem, converts the phase of each sampling point, and then constructs the phase-voltage correspondence to plot and reconstruct the waveform by sorting the phases. It completes the high-frequency signal restoration by relying on the aliasing data of low-speed ADC without triggering signals. It eliminates undersampling timing errors through phase correction, and balances low hardware cost with waveform reconstruction integrity and measurement accuracy.

[0017] In one optional implementation, the aliasing sampling period is determined using the Nyquist sampling theorem based on the sampling frequency of the low-sampling analog-to-digital converter and the frequency of the signal under test, including: According to the Nyquist sampling theorem, the value of the aliasing sampling frequency is no greater than the Nyquist frequency, which is half the sampling frequency. Candidate aliasing sampling frequencies are determined based on the sampling frequency of the low-sampling analog-to-digital converter and the frequency of the signal under test, and the aliasing sampling frequency is obtained according to the constraints of the Nyquist sampling theorem. The aliasing sampling period is determined based on the aliasing sampling frequency.

[0018] The equivalent time sampling method based on precise delay fine-tuning and phase prediction provided by this invention uses half of the sampling frequency as the Nyquist frequency constraint aliasing frequency range, combines the measured signal and ADC sampling frequency to solve for candidate aliasing frequencies and screen compliant values, and then converts them to obtain the aliasing sampling period; this is used as the phase calculation benchmark to ensure that the phase mapping of each sampling point is unique and unambiguous, providing a reliable calculation basis for subsequent accurate waveform reconstruction.

[0019] In one optional implementation, based on the aliasing sampling period and the total duration of multiple aliasing sampled data, the phase of the sampled signal corresponding to each sampling point is calculated, including: Based on the preset delay between multiple aliased sampled data and the sampling period of each aliased sampled data, the absolute sampling time corresponding to each sampled data point is determined. Based on the absolute sampling time corresponding to each sampling data point, a modulo operation is performed on the aliasing sampling period to obtain the sampling point phase corresponding to each sampling point data.

[0020] The equivalent time sampling method based on precision delay fine-tuning and phase prediction provided by this invention calculates the total sampling duration by combining a preset delay and a sampling period, and then performs a modulo operation on the aliased sampling period to strip away the complete period portion within the total duration, retaining only the relative duration within a single period as the sampling phase. This eliminates the positional confusion caused by the absolute duration spanning multiple periods, ensuring that the phase of each sampling point is unique and accurate, thus laying the foundation for orderly waveform reconstruction.

[0021] Secondly, the present invention provides an equivalent time sampling device based on precise delay fine-tuning and phase prediction, the device comprising: The aliasing sampling module is used to acquire multiple aliased sampling data of the signal under test using a low-sampling analog-to-digital converter. The aliased sampling data includes multiple sampling point data with the same sampling period, and the initial sampling time of each aliased sampling data is a continuous sampling time with the same preset delay. The waveform reconstruction module is used to reconstruct the waveform based on multiple aliased sampled data to obtain the complete periodic waveform of the measured signal.

[0022] Thirdly, the present invention provides an electronic device, comprising: a memory and a processor, the memory and the processor being communicatively connected to each other, the memory storing computer instructions, and the processor executing the computer instructions to perform the method described in the first aspect or any corresponding embodiment thereof.

[0023] Fourthly, the present invention provides a computer-readable storage medium storing computer instructions for causing a computer to perform the method described in the first aspect or any corresponding embodiment thereof. Attached Figure Description

[0024] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0025] Figure 1 This is a schematic diagram of the first process of the equivalent time sampling method based on precise delay fine-tuning and phase prediction according to an embodiment of the present invention; Figure 2 This is a schematic diagram of the second process of the equivalent time sampling method based on precise delay fine-tuning and phase prediction according to an embodiment of the present invention; Figure 3 This is a structural block diagram of an equivalent time sampling device based on precision delay fine-tuning and phase prediction according to an embodiment of the present invention; Figure 4 This is a schematic diagram of the hardware structure of an electronic device according to an embodiment of the present invention. Detailed Implementation

[0026] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0027] It is understood that before using the technical solutions disclosed in the various embodiments of the present invention, users should be informed of the types, scope of use, and usage scenarios of the personal information involved in the present invention and their authorization should be obtained in accordance with relevant laws and regulations through appropriate means.

[0028] The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0029] This invention provides an equivalent time sampling method based on precise delay fine-tuning and phase prediction. It uses the low-frequency aliasing signal generated by undersampling as a phase reference and achieves phase positioning of the sampling point through software prediction, thereby improving the sampling accuracy of ultra-high frequency signals while reducing hardware costs.

[0030] According to an embodiment of the present invention, an equivalent time sampling method based on precise delay fine-tuning and phase prediction is provided. It should be noted that the steps shown in the flowchart in the accompanying drawings can be executed in a computer system such as a set of computer-executable instructions. Furthermore, although a logical order is shown in the flowchart, in some cases, the steps shown or described may be executed in a different order than that shown here.

[0031] This embodiment provides an equivalent time sampling method based on precise delay fine-tuning and phase prediction, which can be used in the aforementioned computer system. Figure 1 This is a flowchart of an equivalent time sampling method based on precise delay fine-tuning and phase prediction according to an embodiment of the present invention, such as... Figure 1 As shown, the process includes the following steps: Step S101: Using a low-sampling analog-to-digital converter, acquire multiple aliased sampling data of the signal under test. The aliased sampling data includes multiple sampling point data with the same sampling period, and the initial sampling time of each aliased sampling data is a continuous sampling time with the same preset delay.

[0032] Specifically, the signal under test is an ultra-high frequency periodic signal, and the sampling rate of the low-sampling analog-to-digital converter is much lower than the frequency of the signal under test. For example, when sampling an ultra-high frequency sine wave at a sampling rate of 100MHz, because the sampling rate is much lower than the signal frequency, the system will inevitably enter an undersampling state, and the high-frequency signal will appear as a low-frequency sine wave after aliasing. When the frequency of the signal under test is 56.0123GHz, it will appear as a 12.3MHz sine wave after aliasing.

[0033] Let the aliasing frequency be... Its period is The sampling rate of the data acquisition equipment is... The sampling period is .when When the sampling point is undersampled (i.e., in the undersampled state), the sampled points obtained directly cannot fully represent the original waveform.

[0034] Therefore, this embodiment utilizes a precision delay system to controllably fine-tune the sampling time. The start time of each acquisition is gradually shifted on the time axis, thereby capturing different phase points of the signal during sampling at different initial sampling times. The data acquired in each sampling process is aliased sampling data, and each aliased sampling data includes multiple sampling points with the same sampling period. A low-speed ADC of 100MSa / s level combined with a 1ps precision delay can achieve an equivalent sampling effect of 1TSa / s, enabling the acquisition of VHF signals up to 500GHz.

[0035] The ADC triggers sampling on the rising edge of the sampling clock. After one acquisition is completed, the precision delay system uses a precision programmable delay line to perform step-by-step delay control on the rising edge of the sampling clock, with each step being 1ps. Subsequently, the ADC uses the delayed clock edge as the trigger reference to perform the next acquisition, thereby realizing the successive fine adjustment of the sampling time.

[0036] Step S102: Based on multiple aliased sampling data, waveform reconstruction is performed to obtain the complete periodic waveform of the measured signal.

[0037] Specifically, after a sufficient number of acquisitions, all sampling points are rearranged according to their phase positions to reconstruct the complete periodic waveform of the measured signal.

[0038] The equivalent time sampling method based on precision delay fine-tuning and phase prediction provided in this embodiment uses the low-frequency aliasing signal generated by undersampling as a phase reference. It does not rely on the edge triggering of the measured signal and achieves phase positioning of the sampling point through software prediction. It is also applicable to signals without steep edges, such as pure sine waves, and avoids the negative impact of trigger jitter on accuracy. It uses a low-sampling analog-to-digital converter in conjunction with precision delay and equivalent to achieve high-frequency sampling effect, improving sampling accuracy while reducing hardware costs.

[0039] This embodiment provides an equivalent time sampling method based on precise delay fine-tuning and phase prediction, which can be used in the aforementioned computer system. Figure 2 This is a flowchart of an equivalent time sampling method based on precise delay fine-tuning and phase prediction according to an embodiment of the present invention, such as... Figure 2 As shown, the process includes the following steps: Step S201: Using a low-sampling analog-to-digital converter, multiple aliased sampling data of the signal under test are acquired. The aliased sampling data includes multiple sampling point data with the same sampling period. The initial sampling time of each aliased sampling data is a continuous sampling time with the same preset delay.

[0040] Specifically, step S201 includes: Step S2011: Set the initial sampling time of the first aliased sampling data, acquire multiple sampling point data according to the preset sampling period, and combine the multiple sampling point data into the first aliased sampling data according to the order of the sampling time.

[0041] Specifically, the start time of this first round of data collection is preset as the initial sampling time, and the initial sampling time of the first round of aliased data is set as follows: The preset sampling period is Then the nth sampling time in the first round is:

[0042] Where N is the number of sampling points in one round of sampling. One round of sampling is performed to obtain N sampling points. The sampling time and voltage value of each point are recorded as sampling point data.

[0043] The ADC chip continuously acquires signal voltage at a fixed preset sampling period, generating a set of sampling points in sequence. Each sampling point is bound to its corresponding acquisition time and corresponding voltage value. All sampling points are arranged and integrated according to the order in which they are acquired to form the first complete set of aliased sampling data and store it.

[0044] Step S2012: Fine-tune the initial sampling time of the first aliased sampling data according to a preset delay to obtain the initial sampling time of the next aliased sampling data.

[0045] Specifically, using a precision delay system, the initial sampling time of the first aliased sampling data is slightly adjusted backward according to a preset delay, where the preset delay is... Then the initial sampling time for the second round of sampling is: And so on, the initial sampling time for the i-th round of sampling is: .

[0046] Step S2013: Based on the initial sampling time of the next aliased sampling data, acquire multiple sampling point data according to the preset sampling period, and combine the multiple sampling point data into the next aliased sampling data according to the order of the sampling time.

[0047] Specifically, based on the initial sampling time of the next round of aliased sampled data, the corresponding sampling time sequence for the second round is as follows:

[0048] The sampling time sequence for the i-th round is:

[0049] Based on the sampling time sequence of each round, multiple sampling point data are collected, and the multiple sampling point data are combined into the mixed sampling data of the corresponding round according to the order of sampling time.

[0050] Step S2014: Repeat the process of fine-tuning the initial sampling time of the next aliased sampling data according to the preset delay and acquiring multiple sampling point data to obtain multiple aliased sampling data.

[0051] Specifically, the initial sampling time of the next aliased sampling data is repeatedly adjusted according to the preset delay. In each round, the preset delay is added on the initial time of the previous round, the sampling starting point is updated, and another set of aliased sampling data is collected. This delay offset and batch sampling process is repeated until the total accumulated delay covers the complete sampling period. Finally, multiple sets of aliased sampling data with time offsets are output in batches to realize the data acquisition of all phase points of the measured signal.

[0052] The equivalent time sampling method based on precision delay fine-tuning and phase prediction provided in this embodiment can cover the entire phase range of the measured signal with a low-speed ADC by successively fine-tuning the initial sampling time and collecting multiple sets of mixed sampling data in batches, without the need for a matching trigger circuit. The waveform is reconstructed by phase sorting of multiple batches of sampling points, which greatly improves the time domain resolution, avoids the phase jitter distortion of traditional equivalent sampling, reduces the hardware bandwidth and sampling rate requirements, and effectively reduces the cost of measurement equipment.

[0053] In some optional implementations, the length of the preset delay is determined based on the frequency of the signal under test and the target measurement accuracy, and the total duration of the preset delay for each aliased sample data covers at least one complete sampling period of the signal under test.

[0054] Specifically, each time the initial sampling time is increased A total of M data collections were performed, with N sampling points collected each time.

[0055] The total number of data collections M should satisfy:

[0056] That is, the cumulative amount of delay fine-tuning covers at least one complete sampling period Ts to ensure that the sampling points are distributed across all phases of the measured signal period.

[0057] The equivalent time sampling method based on precision delay fine-tuning and phase prediction provided in this embodiment flexibly matches the preset delay according to the frequency of the signal under test and the required measurement accuracy. The higher the accuracy requirement, the smaller the delay step, balancing measurement resolution and acquisition efficiency. At the same time, the total delay is limited to cover the entire sampling period, ensuring that the sampling points fill the entire phase range of the signal, avoiding the loss of waveform reconstruction, and ensuring the complete and accurate restoration of the UHF signal waveform.

[0058] In some optional implementations, a larger preset delay results in a faster measurement speed but a lower waveform reconstruction accuracy; a smaller preset delay results in a slower measurement speed but a higher waveform reconstruction accuracy.

[0059] Specifically, time delay step The selection of the preset delay directly affects the temporal resolution of the waveform reconstruction. Specifically, the preset delay... The smaller the value, the higher the time-domain resolution of the reconstructed waveform, but the more acquisitions are required, and the longer the total measurement time. Preset delay. The larger the value, the faster the measurement speed, but the lower the reconstruction accuracy.

[0060] In this embodiment, the delay step of the preset delay can be flexibly set according to the frequency of the signal being measured and the required measurement accuracy. Typical values ​​include 1ps, 0.1ps or 10ps.

[0061] The equivalent time sampling method based on precise delay fine-tuning and phase prediction provided in this embodiment clarifies the trade-off between preset delay and measurement performance: increasing the delay can reduce the number of sampling rounds and improve the measurement rate, but the sampling phase interval becomes wider, resulting in the loss of waveform details and a decrease in accuracy; reducing the delay can refine the phase sampling points and improve the waveform restoration accuracy, but it will increase the number of sampling rounds and lengthen the overall measurement time. The delay should be balanced as needed to adapt to different measurement speed and accuracy requirements.

[0062] Step S202: Based on multiple aliased sampling data, waveform reconstruction is performed to obtain the complete periodic waveform of the measured signal.

[0063] Specifically, step S202 includes: Step S2021: Based on the sampling frequency of the low-sampling analog-to-digital converter and the frequency of the signal under test, the aliasing sampling period is determined using the Nyquist sampling theorem.

[0064] Specifically, the Nyquist sampling theorem stipulates that the sampling frequency must be at least twice the highest frequency of the signal to reconstruct the signal without distortion. Furthermore, the Nyquist sampling theorem defines the Nyquist frequency as half the sampling frequency, which is the highest signal frequency that can be reconstructed without aliasing. Aliasing refers to the phenomenon where, if the sampling rate is insufficient, high-frequency components are incorrectly reconstructed as low-frequency signals, leading to distortion.

[0065] Therefore, the aliasing sampling period can be determined by using the sampling frequency of the low-sampling analog-to-digital converter, the frequency of the signal under test, and the Nyquist frequency.

[0066] In some optional implementations, step S2021 above includes: Step a1: According to the Nyquist sampling theorem, the value of the aliasing sampling frequency is no greater than the Nyquist frequency, which is half of the sampling frequency.

[0067] Specifically, the Nyquist frequency is the critical upper limit for no frequency aliasing. Constrained by the undersampling aliasing rule, the final effective aliasing sampling frequency must fall within the range of 0 to the Nyquist frequency. Frequency values ​​outside this range will result in multiple solutions aliasing, thus defining the boundary of the aliasing frequency value.

[0068] Step a2: Determine the candidate aliasing sampling frequency based on the sampling frequency of the low-sampling analog-to-digital converter and the frequency of the signal under test, and obtain the aliasing sampling frequency according to the constraints of the Nyquist sampling theorem.

[0069] Specifically, the general formula for calculating the undersampling aliasing frequency is:

[0070] in, This refers to the aliasing sampling frequency; The actual high-frequency signal being measured; The sampling frequency of the low-sampling analog-to-digital converter; For positive integers, the selection rule is: let the calculated result be... satisfy:

[0071] The absolute value of the high-frequency signal frequency minus an integer multiple of the sampling rate falls between 0 and the Nyquist frequency. The result between ) is the low-frequency aliasing observed. .

[0072] First, multiple candidate aliasing frequencies are calculated using the ADC sampling frequency and the actual frequency of the measured signal. Then, the Nyquist frequency constraint is applied to filter the frequencies, retaining only those values ​​that do not exceed the Nyquist frequency. After filtering, the effective aliasing sampling frequency is uniquely determined, avoiding the problem of multi-value ambiguity.

[0073] Step a3: Determine the aliasing sampling period based on the aliasing sampling frequency.

[0074] Specifically, the period and frequency are reciprocals of each other. The aliasing sampling period can be obtained by taking the reciprocal of the effective aliasing sampling frequency obtained in the previous step. This period represents the duration of a single complete oscillation of the low-frequency aliasing signal observed after undersampling, and is used as the basic parameter for phase calculation in the next process.

[0075] The equivalent time sampling method based on precise delay fine-tuning and phase prediction provided in this embodiment uses half of the sampling frequency as the Nyquist frequency constraint aliasing frequency range, combines the measured signal and ADC sampling frequency to solve for candidate aliasing frequencies and screen compliant values, and then converts them to obtain the aliasing sampling period; this is used as the phase calculation benchmark to ensure that the phase mapping of each sampling point is unique and unambiguous, providing a reliable calculation basis for subsequent accurate waveform reconstruction.

[0076] Step S2022: Based on the aliasing sampling period and the total duration of multiple aliasing sampling data, calculate the sampling point phase of the measured signal corresponding to each sampling point.

[0077] Specifically, based on the aliasing sampling period, and combined with the total time of each sampling group, the relative phase of each voltage sampling point falling on the measured period waveform is calculated.

[0078] In an optional implementation, step S2022 includes: Step b1: Based on the preset delay between multiple aliased sampled data and the sampling period of each aliased sampled data, determine the absolute sampling time corresponding to each sampled data point.

[0079] Specifically, the preset delay is used uniformly between each group of samples, and the preset sampling period remains unchanged during a single group of acquisitions; combined with the number of acquisition rounds and the number of sampling points per group, the total time from the start of the entire acquisition process to the point of capture is calculated for any sampling point. For the i-th acquisition (the delay is...), The equivalent absolute sampling time for the nth sampling point is: .

[0080] Step b2: Based on the absolute sampling time corresponding to each sampling data point, perform a modulo operation on the aliasing sampling period to obtain the sampling point phase corresponding to each sampling point data.

[0081] Specifically, the signal phase corresponding to the absolute sampling time of each sampled data point is:

[0082] in, Indicates the period of the signal The modulo operation subtracts an integer number of aliasing cycles from the total duration, retaining only the remaining time (less than one cycle). This remaining duration is the relative phase. Phase range: 0 ~ The current sampling point indicates how long it has been since the start of the most recent waveform cycle before phase occurs, thus eliminating the time redundancy caused by spanning many cycles. Only a value between 0 and one cycle is needed to represent a unique position on the waveform.

[0083] The equivalent time sampling method based on precise delay fine-tuning and phase prediction provided in this embodiment calculates the total sampling duration by combining the preset delay and sampling period. Then, it performs a modulo operation on the aliased sampling period to strip away the complete period portion within the total duration and retain only the relative duration within a single period as the sampling phase. This eliminates the position confusion caused by the absolute duration spanning multiple periods, ensuring that the phase of each sampling point is unique and accurate, thus laying the foundation for orderly waveform reconstruction.

[0084] Step S2023: Sort the sampling points from smallest to largest phase, and combine the corresponding sampling point data to obtain the phase-voltage sequence.

[0085] Specifically, the phase and voltage of all sampling points are sorted according to their phase. Sort by size from smallest to largest to obtain the phase-voltage sequence:

[0086] Where K = M × N is the total number of sampling points.

[0087] Step S2024: Plot a scatter plot or line graph with phase as the abscissa and voltage as the ordinate to obtain the complete periodic waveform of the measured signal.

[0088] Specifically, by plotting a scatter plot or line graph with phase as the horizontal axis and voltage as the vertical axis, the waveform reconstruction result of the measured signal within a complete cycle of at least one full period can be obtained.

[0089] The equivalent time sampling method based on precision delay fine-tuning and phase prediction provided in this embodiment calculates the aliasing period based on the Nyquist sampling theorem, converts the phase of each sampling point, and then constructs the phase-voltage correspondence to plot and reconstruct the waveform by sorting the phases. It completes the high-frequency signal restoration based on the aliasing data of the low-speed ADC without the need for a trigger signal. The undersampling timing disorder is eliminated by phase correction, which takes into account both low hardware cost and waveform reconstruction integrity and measurement accuracy.

[0090] In one specific embodiment, the experimental conditions are as follows: the signal under test is a high-frequency sine wave with an amplitude of 1V; the sampling device is a 100MHz sampling rate ADC with a sampling period of 10ns; the precision delay is in steps of 1ps, ranging from 0 to 10ns; the number of sampling points per session is 100 (duration). The total number of sampling times is 100. The specific steps for sampling using the equivalent time sampling method based on precise delay fine-tuning and phase prediction provided in this embodiment are as follows: (1) The high-frequency sine wave signal was sampled using an ADC with a sampling rate of 100MHz, and the aliasing frequency was measured to be 12.3Hz.

[0091] (2) Set the initial sampling time to Collect 100 data points and record all sampling times and voltage values.

[0092] (3) Delay 1ps, in order to Collect and record 100 more data points at the starting time.

[0093] (4) Repeat step (2), increasing the delay by 1ps each time, until the cumulative delay reaches 10ns.

[0094] (5) For all 100×100=10000 sampling points, calculate the signal phase at each point. Where Tm = 1 / 12.3MHz ≈ 81.3ns.

[0095] (6) Sort all sampling points in ascending order of phase, and plot the waveform with phase as the horizontal axis and voltage as the vertical axis.

[0096] The reconstructed waveform contains one or more complete and true sine wave cycles.

[0097] This embodiment also provides an equivalent time sampling device based on precise delay fine-tuning and phase prediction. This device is used to implement the above embodiments and preferred embodiments, and details already described will not be repeated. As used below, the term "module" can refer to a combination of software and / or hardware that implements a predetermined function. Although the device described in the following embodiments is preferably implemented in software, hardware implementation, or a combination of software and hardware, is also possible and contemplated.

[0098] This embodiment provides an equivalent time sampling device based on precise delay fine-tuning and phase prediction, such as... Figure 3 As shown, it includes: The aliasing sampling module 301 is used to acquire multiple aliased sampling data of the signal under test using a low-sampling analog-to-digital converter. The aliased sampling data includes multiple sampling point data with the same sampling period, and the initial sampling time of each aliased sampling data is a continuous sampling time with the same preset delay.

[0099] The waveform reconstruction module 302 is used to reconstruct the waveform based on multiple aliased sampled data to obtain the complete periodic waveform of the measured signal.

[0100] In some alternative implementations, the aliasing sampling module 301 includes: The first sampling unit is used to set the initial sampling time of the first aliased sampling data, acquire multiple sampling point data according to a preset sampling period, and combine the multiple sampling point data into the first aliased sampling data according to the order of the sampling time.

[0101] The sampling time fine-tuning unit is used to fine-tune the initial sampling time of the first aliased sampling data according to a preset delay, so as to obtain the initial sampling time of the next aliased sampling data.

[0102] The second sampling unit is used to acquire multiple sampling point data according to a preset sampling period based on the initial sampling time of the next aliased sampling data, and to combine the multiple sampling point data into the next aliased sampling data according to the order of the sampling time.

[0103] The repeated sampling unit is used to repeatedly adjust the initial sampling time of the next aliased sampling data according to a preset delay, and to acquire multiple sampling point data to obtain multiple aliased sampling data.

[0104] In some alternative implementations, the waveform reconstruction module 302 includes: The aliasing sampling period determination unit is used to determine the aliasing sampling period based on the sampling frequency of the low-sampling analog-to-digital converter and the frequency of the signal under test, using the Nyquist sampling theorem.

[0105] The phase calculation unit is used to calculate the phase of the measured signal corresponding to each sampling point based on the aliasing sampling period and the total duration of multiple aliasing sampling data.

[0106] The phase-voltage sequence determination unit is used to sort the phases of each sampling point from smallest to largest, and combine the corresponding sampling point data to obtain the phase-voltage sequence.

[0107] The waveform plotting unit is used to plot scatter plots or line graphs with phase as the horizontal axis and voltage as the vertical axis to obtain the complete periodic waveform of the measured signal.

[0108] The equivalent time sampling device based on precise delay fine-tuning and phase prediction provided in this embodiment of the invention can execute the equivalent time sampling method based on precise delay fine-tuning and phase prediction provided in any embodiment of the invention, and has the corresponding functional modules and beneficial effects for executing the method. Further functional descriptions of the above modules and units are the same as in the corresponding embodiments described above, and will not be repeated here.

[0109] Figure 4 This is a schematic diagram of the structure of an electronic device provided in an embodiment of the present invention.

[0110] The following is a detailed reference. Figure 4 This diagram illustrates a structural schematic suitable for implementing an electronic device according to embodiments of the present invention. The electronic device may include a processor (e.g., a central processing unit, graphics processor, etc.) 401, which can perform various appropriate actions and processes according to a program stored in read-only memory (ROM) 402 or a program loaded from memory 408 into random access memory (RAM) 403. The RAM 403 also stores various programs and data required for the operation of the electronic device. The processor 401, ROM 402, and RAM 403 are interconnected via a bus 404. An input / output (I / O) interface 405 is also connected to the bus 404.

[0111] Typically, the following devices can be connected to I / O interface 405: input devices 406 including, for example, touchscreens, touchpads, keyboards, mice, cameras, microphones, accelerometers, gyroscopes, etc.; output devices 407 including, for example, liquid crystal displays (LCDs), speakers, vibrators, etc.; memory devices 408 including, for example, magnetic tapes, hard disks, etc.; and communication devices 409. Communication device 409 allows electronic devices to communicate wirelessly or wiredly with other devices to exchange data. Although Figure 4 Electronic devices with various devices are shown, but it should be understood that it is not required to implement or have all of the devices shown, and more or fewer devices may be implemented or have instead.

[0112] In particular, according to embodiments of the present invention, the processes described above with reference to the flowcharts can be implemented as computer software programs. For example, embodiments of the present invention include a computer program product comprising a computer program carried on a non-transitory computer-readable medium, the computer program containing program code for performing the methods shown in the flowcharts. In such embodiments, the computer program can be downloaded and installed from a network via a communication device 409, or installed from a memory 408, or installed from a ROM 402. When the computer program is executed by the processor 401, it performs the functions defined in the equivalent time sampling method based on precise delay fine-tuning and phase prediction according to embodiments of the present invention.

[0113] Figure 4 The electronic device shown is merely an example and should not be construed as limiting the functionality and scope of use of the embodiments of the present invention.

[0114] This invention also provides a computer-readable storage medium. The methods described above according to embodiments of the invention can be implemented in hardware or firmware, or implemented as recordable on a storage medium, or implemented as computer code originally stored on a remote storage medium or a non-transitory machine-readable storage medium and subsequently stored on a local storage medium after being downloaded via a network. Thus, the methods described herein can be processed by software stored on a storage medium using a general-purpose computer, a dedicated processor, or programmable or dedicated hardware. The storage medium can be a magnetic disk, optical disk, read-only memory, random access memory, flash memory, hard disk, or solid-state drive, etc.; further, the storage medium can also include combinations of the above types of memory. It is understood that computers, processors, microprocessor controllers, or programmable hardware include storage components capable of storing or receiving software or computer code. When the software or computer code is accessed and executed by the computer, processor, or hardware, the equivalent time sampling method based on precise delay fine-tuning and phase prediction shown in the above embodiments is implemented.

[0115] Although embodiments of the invention have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of the invention, and such modifications and variations all fall within the scope defined by the appended claims.

Claims

1. An equivalent time sampling method based on precise delay fine-tuning and phase prediction, characterized in that, The method includes: Using a low-sampling analog-to-digital converter, multiple aliased sampling data of the signal under test are acquired. The aliased sampling data includes multiple sampling point data with the same sampling period, and the initial sampling time of each aliased sampling data is a continuous sampling time with the same preset delay. Waveform reconstruction is performed based on multiple aliased sampled data to obtain the complete periodic waveform of the measured signal.

2. The method according to claim 1, characterized in that, Using a low-sampling analog-to-digital converter, multiple aliased sampled data of the measured signal are acquired, including: Set the initial sampling time for the first aliased sampling data, acquire multiple sampling point data according to the preset sampling period, and combine the multiple sampling point data into the first aliased sampling data according to the order of the sampling time; The initial sampling time of the first aliased sampled data is finely adjusted according to a preset delay to obtain the initial sampling time of the next aliased sampled data; Based on the initial sampling time of the next aliased sampling data, multiple sampling point data are acquired according to a preset sampling period, and the multiple sampling point data are combined into the next aliased sampling data according to the order of sampling time. Repeat the process of fine-tuning the initial sampling time of the next aliased sampling data according to the preset delay and acquiring multiple sampling point data to obtain multiple aliased sampling data.

3. The method according to claim 1 or 2, characterized in that, The duration of the preset delay is determined based on the frequency of the signal under test and the target measurement accuracy. The total duration of the preset delay for each aliased sampled data shall at least cover one complete sampling period of the signal under test.

4. The method according to claim 3, characterized in that, The larger the preset delay, the faster the measurement speed, and the lower the waveform reconstruction accuracy. The smaller the preset delay, the slower the measurement speed and the higher the waveform reconstruction accuracy.

5. The method according to claim 1, characterized in that, The sampling point data is the voltage corresponding to the sampling point. Based on multiple aliased sampling data, waveform reconstruction is performed to obtain the complete periodic waveform of the measured signal, including: Based on the sampling frequency of the low-sampling analog-to-digital converter and the frequency of the signal under test, the aliasing sampling period is determined using the Nyquist sampling theorem. Based on the aliasing sampling period and the total duration of multiple aliasing sampling data, calculate the sampling point phase of the measured signal corresponding to each sampling point; The phase-voltage sequence is obtained by sorting the sampling points from smallest to largest according to their phases and combining the corresponding sampling point data. Plot a scatter plot or line graph with phase as the horizontal axis and voltage as the vertical axis to obtain the complete periodic waveform of the measured signal.

6. The method according to claim 5, characterized in that, Based on the sampling frequency of the low-sampling analog-to-digital converter and the frequency of the signal under test, the aliasing sampling period is determined using the Nyquist sampling theorem, including: According to the Nyquist sampling theorem, the value of the aliasing sampling frequency is no greater than the Nyquist frequency, which is half of the sampling frequency. Candidate aliasing sampling frequencies are determined based on the sampling frequency of the low-sampling analog-to-digital converter and the frequency of the signal under test, and the aliasing sampling frequency is obtained according to the constraints of the Nyquist sampling theorem. The aliasing sampling period is determined based on the aliasing sampling frequency.

7. The method according to claim 5, characterized in that, Based on the aliasing sampling period and the total duration of multiple aliased sampled data, the phase of the measured signal corresponding to each sampling point is calculated, including: Based on the preset delay between multiple aliased sampled data and the sampling period of each aliased sampled data, the absolute sampling time corresponding to each sampled data point is determined. Based on the absolute sampling time corresponding to each sampling data point, a modulo operation is performed on the aliasing sampling period to obtain the sampling point phase corresponding to each sampling point data.

8. An equivalent time sampling device based on precise delay fine-tuning and phase prediction, characterized in that, The device includes: The aliasing sampling module is used to acquire multiple aliased sampling data of the signal under test using a low-sampling analog-to-digital converter. The aliased sampling data includes multiple sampling point data with the same sampling period, and the initial sampling time of each aliased sampling data is a continuous sampling time with the same preset delay. The waveform reconstruction module is used to reconstruct the waveform based on multiple aliased sampled data to obtain the complete periodic waveform of the measured signal.

9. An electronic device, characterized in that, include: A memory and a processor, the memory and the processor being communicatively connected to each other, the memory storing computer instructions, the processor executing the computer instructions to perform the method of any one of claims 1 to 7.

10. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores computer instructions for causing the computer to perform the method of any one of claims 1 to 7.

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