Multi-domain synchronous real-time analysis and display method for complex signals in digital oscilloscope

Abstract

The application discloses a multi-domain synchronous real-time analysis and display method for complex signals in a digital oscilloscope. First, a trigger module is used to control a memory to store sampling data and record the starting position of the sampling data storage. An upper computer reads data from the memory according to the starting position and divides the data into two paths. One path is displayed through a time domain display window. The other path is sent to a multi-domain analysis module. According to the display mode set by the digital oscilloscope, panoramic analysis is carried out through a panoramic analysis module to realize real-time display, and detail analysis is carried out through a detail analysis module to realize real-time display. Thus, the problem that the signal cannot be analyzed in multiple domains or the panoramic view and the details cannot be considered simultaneously when the signal is analyzed in multiple domains in the measurement process is solved.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of digital oscilloscope, more specifically, it relates to a multi-domain synchronous real-time analysis and display method of complex signals in a digital oscilloscope. BACKGROUND

[0002] In actual measurement, sometimes not only the analysis of signals in the time domain is needed, but also the analysis of other domains such as frequency domain, time-frequency domain, etc. The parameters between different domains of the signal and the analysis results often have correlations, which often reveal the deep characteristics of the signal. In addition, for multi-standard signal analysis in the same system, the logical correlation of parameters of different standard signals at the same time often reveals the inherent characteristics of the system.

[0003] In the actual communication test scene, the test personnel need to demodulate and analyze a group of modulated signals at the receiving end and observe their frequency band occupation. The traditional test method needs to use signal measuring instruments including oscilloscopes and spectrum analyzers to capture the group of signals and observe them from the time domain, frequency domain, modulation domain, etc. to draw conclusions. In order to test whether the signal meets the transmission requirements after modulation and before transmission, the signal-to-noise ratio and modulation parameters need to be measured. The spectrum analyzer can easily obtain the signal-to-noise ratio of the transmitted signal, but it cannot observe the overall shape and quality of the signal from the time domain. Using a digital oscilloscope can observe the time domain waveform of the measured signal at a certain time resolution, but it is not easy to obtain the frequency domain parameters of the signal. The traditional digital oscilloscope does not have signal demodulation function, so the information that can be obtained is very limited, and it can only speculate whether the modulation type of the signal is amplitude modulation or frequency modulation. To dig deeper information, such as the relationship between the amplitude or frequency of the modulated signal and time, the modulation depth of the amplitude modulated signal, the frequency offset of the frequency modulated signal, etc., multiple test instruments are also needed. Complicated measurement parameter configuration and low time correlation caused by physical separation of instruments will greatly affect the accuracy of test results, leading to inaccurate analysis conclusions.

[0004] At present, there is no instrument that can analyze these correlations, and there are almost no patents related to multi-domain analysis methods. Only single-domain analysis methods are studied, such as various parameter measurement methods in the time domain, real-time wideband spectrum methods in the frequency domain, time-frequency analysis methods in the time-frequency domain, demodulation methods in the modulation domain, etc. There is no method that can simultaneously analyze multiple domains. SUMMARY

[0005] The present application aims at overcoming the deficiencies of the prior art, and provides a multi-domain synchronous real-time analysis and display method for complex signals in a digital oscilloscope, a multi-domain analysis method for signals based on digital down-conversion, and realization of multi-domain synchronous real-time panoramic and detailed analysis of the digital oscilloscope, so that multi-dimensional deep analysis of the measured signals can be performed at the same time.

[0006] To achieve the above-mentioned application purposes, the multi-domain synchronous real-time analysis and display method for complex signals in a digital oscilloscope comprises the following steps:

[0007] (1) connecting the measured signals to the digital oscilloscope after power-on, enabling the writing of the memory in the digital oscilloscope, and setting the display mode of the digital oscilloscope: panoramic analysis real-time display or detailed analysis real-time display;

[0008] (2) collecting the measured signals by the collection system of the digital oscilloscope to obtain N parallel sampling data, and then dividing the N parallel sampling data into two paths, one of which is sent to the memory and the other of which is sent to the trigger module;

[0009] (3) in the trigger module, the N parallel sampling data are compared by the parallel data comparator to obtain N trigger comparison signals, and then the N trigger comparison signals are monitored, and if any of the trigger comparison signals is at a high level, a trigger signal is generated and fed back to the memory;

[0010] (4) when the memory detects the rising edge of the trigger signal, the current sampling data storage position in the memory is recorded as a time stamp P trig , and then the memory starts calculation with the time stamp P trig as the starting address, and records the sampling data with a length of D as the multi-domain analysis data, wherein D is the time domain display window length of the host computer;

[0011] (5) real-time synchronous display of the multi-domain analysis data;

[0012] (5.1) the host computer reads the multi-domain analysis data from the memory, and then divides the multi-domain analysis data into two paths through the parallel splitter A, one of which is time domain displayed through the time domain display window of the host computer after parallel-serial conversion, decimation, correction and interpolation processing, and the other of which is sent to the multi-domain analysis module;

[0013] (5.2) the multi-domain analysis data are divided into two paths through the parallel splitter B, one of which is sent to the panoramic analysis module to enter step (5.3), and the other of which is sent to the detailed analysis module to enter step (5.4);

[0014] (5.3) panoramic analysis real-time display;

[0015] (5.3.1), the multi-domain analysis data is converted into serial data by parallel-serial converter B;

[0016] (5.3.2), when the display mode of the digital oscilloscope is set as panoramic analysis real-time display, data selector C selects the serial data to store in data buffer;

[0017] (5.3.3), the short-time Fourier transform module reads the serial data from the data buffer and performs short-time Fourier transform to obtain multi-frame FFT data;

[0018] (5.3.4), the host computer draws each frame of FFT data into a spectrum graph, and then displays each spectrum graph in frequency domain through the frequency domain display window of the host computer; in addition, the host computer superimposes each frame of FFT data in the time axis direction, converts the amplitude value into a color value, and draws a time-frequency graph and a time / frequency / amplitude three-dimensional solid graph, and then displays the time-frequency graph in time-frequency domain through the time-frequency domain display window of the host computer, and displays the time / frequency / amplitude three-dimensional solid graph in time / frequency / amplitude three-dimensional display through the time / frequency / amplitude three-dimensional display window of the host computer;

[0019] (5.4), detail analysis real-time display;

[0020] (5.4.1), the multi-domain analysis data is divided into two paths by parallel shunt C, one path of the multi-domain analysis data is input into mixer I, and the other path of the multi-domain analysis data is input into mixer Q;

[0021] (5.4.2), N parallel direct frequency synthesizers DDS generate N parallel sine signals and N parallel cosine signals, and then input the N parallel cosine signals into mixer I and input the N parallel sine signals into mixer Q;

[0022] (5.4.3), mixer I mixes the multi-domain analysis data and the N parallel cosine signals to obtain N parallel I data; the N parallel I data is divided into two paths by parallel shunt D, one path is sent into parallel-serial conversion module C to be converted into serial I data; the other path is sent into parallel decimation filter structure to perform parallel decimation filtering to obtain serial decimation I data; then the serial I data and the serial decimation I data are selected by data selector A to be output, and the output result is input into the serial decimation filter structure to perform serial decimation filtering to obtain the final serial I data;

[0023] (5.4.4), the mixed Q of the multi-domain analysis data and the N-parallel sine signal is mixed by the mixer Q, and N-parallel Q data is obtained; the N-parallel Q data is divided into two paths by the parallel splitter E, one path is sent into the parallel-serial conversion module D to be converted into serial Q data; the other path is sent into the parallel extraction filter structure to be extracted and filtered in parallel, and serial extraction Q data is obtained; then the serial Q data and the serial extraction Q data are selected and output by the data selector B, and the output result is input into the serial extraction filter structure to be extracted and filtered in series, and the final serial Q data is obtained;

[0024] (5.4.5), when the display mode of the digital oscilloscope is set to the detail analysis real-time display, the data selector C selects the serial I and Q data to be stored in the data buffer;

[0025] (5.4.6), according to steps (5.3.3)-(5.3.4), the short-time Fourier transform module reads the serial I and Q data from the data buffer and processes and displays; at the same time, the amplitude / phase / frequency calculation module reads the serial I and Q data from the data buffer, calculates the amplitude / phase / frequency discrete sequence, draws the amplitude-time curve, the phase-time curve and the frequency-time curve, and then displays the modulation domain through the modulation domain display window of the host computer.

[0026] The application aims to achieve the following purposes:

[0027] The application is a multi-domain synchronous real-time analysis display method for complex signals in a digital oscilloscope, which first controls the memory to store sampling data and record the starting position of the sampling data storage by using a trigger module, and the host computer reads the data from the memory according to the starting position and divides the data into two paths, one path is displayed through the time domain display window; the other path is sent into a multi-domain analysis module, and according to the display mode set by the digital oscilloscope, panoramic analysis real-time display is performed through a panoramic analysis module, and detail analysis real-time display is performed through a detail analysis module, so that the problem that the signal cannot be analyzed in multiple domains or the panoramic and detail cannot be considered simultaneously when the signal is analyzed in multiple domains during the measurement process is solved.

[0028] Meanwhile, the application also has the following beneficial effects:

[0029] (1) The characteristic information in the full bandwidth of the signal can be quickly obtained through the panoramic analysis display;

[0030] (2) The signal characteristics of interest can be analyzed locally and finely through the detail analysis display;

[0031] (3) By displaying the panoramic and detailed information of the signal in multiple domains, a single digital oscilloscope can build a more complete test system and perform multi-dimensional and in-depth analysis of the signal under test at the same time. Attached Figure Description

[0032] Figure 1 This is a block diagram illustrating the principle of a multi-domain synchronous real-time analysis and display method for complex signals in a digital oscilloscope according to the present invention.

[0033] Figure 2 yes Figure 1 The diagram shows the structure of the short-time Fourier transform module.

[0034] Figure 3 It is a real-time display of the effect of multi-domain panoramic analysis;

[0035] Figure 4 yes Figure 1 The diagram shows the structure of the parallel mixer.

[0036] Figure 5 This is a structural diagram of a parallel CIC filter;

[0037] Figure 6 This is a structural diagram of a parallel half-band filter;

[0038] Figure 7 This is a structural diagram of a serial CIC filter;

[0039] Figure 8 This is a real-time display of the multi-domain detail analysis. Detailed Implementation

[0040] The specific embodiments of the present invention will now be described with reference to the accompanying drawings to enable those skilled in the art to better understand the invention. It should be particularly noted that in the following description, detailed descriptions of known functions and designs that might obscure the main content of the invention will be omitted here.

[0041] Example

[0042] In this embodiment, as Figure 1 As shown, the present invention provides a method for multi-domain synchronous real-time analysis and display of complex signals in a digital oscilloscope, comprising the following steps:

[0043] (1) Power on the digital oscilloscope and connect the signal to be measured. The signal to be measured is a frequency modulation signal with a carrier frequency of 50MHz, a modulation frequency of 50KHz, a frequency deviation of 10MHz, and a modulation type of sine.

[0044] Enable write to the memory in the digital oscilloscope, set the display mode of the digital oscilloscope: panoramic analysis real-time display or detailed analysis real-time display, set the time base and amplitude range of the time domain display window of the digital oscilloscope according to the signal under test, and select the appropriate window function type;

[0045] (2) The sampling rate of the digital oscilloscope is 20GSPS and the bandwidth is 8GHz. The 250MHz clock is used to collect data from the signal under test input to the digital oscilloscope, and 80 parallel sampling data are obtained. Then, the 80 parallel sampling data are divided into two paths, one of which is sent to the memory and the other is sent to the trigger module.

[0046] (3) In the trigger module, the 80 parallel sampling data are processed by a parallel data comparator to obtain 80 trigger comparison signals. Then, the 80 trigger comparison signals are monitored. If any one of the trigger comparison signals is high, a trigger signal is generated and fed back to the memory.

[0047] (4) When the memory detects the rising edge of the trigger signal, it records the location of the currently sampled data in the memory and uses it as a timestamp P. trig Then the memory uses timestamp P trig The calculation starts from the starting address, and the sampled data of length D is recorded as multi-domain analysis data, where D is the length of the time domain display window of the host computer;

[0048] (5) Real-time synchronous display of multi-domain analysis data;

[0049] (5.1) The host computer reads the multi-domain analysis data from the memory, and then splits it into two paths through the parallel splitter A. One path of multi-domain analysis data is processed by parallel-to-serial conversion, decimation, correction and interpolation, and then displayed in the time domain through the time domain display window of the host computer; the other path of multi-domain analysis data is sent to the multi-domain analysis module.

[0050] (5.2) The multi-domain analysis data is split into two paths by the parallel splitter B. One path of multi-domain analysis data is sent to the panoramic analysis module and proceeds to step (5.3); the other path of multi-domain analysis data is sent to the detailed analysis module and proceeds to step (5.4).

[0051] (5.3) Real-time display of panoramic analysis;

[0052] (5.3.1) Multi-domain analysis data is converted into serial data by parallel-to-serial converter B. At this time, the serial data contains the characteristic information of the signal within the full bandwidth, but the frequency resolution is low.

[0053] (5.3.2) When the display mode of the digital oscilloscope is set to panoramic analysis real-time display, the analysis bandwidth of the frequency domain display window is set to the full bandwidth 8GHz, the FFT length of the frequency domain analysis window is set to L=1024, the window function movement step of the short time Fourier transform module is set to S=16, and the data selector C selects serial data A and stores it in the data buffer.

[0054] (5.3.3) The short-time Fourier transform module reads serial data from the data buffer and performs short-time Fourier transform to obtain multi-frame FFT data;

[0055] In this embodiment, the structure of the short-time Fourier transform module is as follows: Figure 2 As shown, assume that the length of each FFT calculation is L, and the window function of the short-time Fourier transform moves by S.

[0056] During the first frame of data transmission, the data buffer outputs L data points to RAM. The data is stored sequentially starting from address 0. At this time, the data in RAM are D0, D1, D2, ..., D... L-1 A total of L pairs of I and Q data;

[0057] During the FFT operation of the first frame of data, the subsequent FFT module reads data from RAM, from address 0 to address L-1, reading data sequentially as D0, D1, D2, ..., D... L-1 ;

[0058] During the second frame data transmission, the data buffer transmits S data points to RAM. RAM starts writing from address 0 and continues until address S-1 is reached, overwriting the data stored in the previous frame at that address. After the writing is complete, the data in RAM is sequentially D. L D L+1 D L+2 D L+S-1 D S D S+1 D L-1 A total of L pairs of I and Q data;

[0059] When performing the FFT operation on the second frame of data, the subsequent FFT module reads data from RAM sequentially starting from address S. When the read address exceeds L and the number of data items is less than L, it returns to address 0 and continues reading data sequentially. The read data is in the order of D. S D S+1 D L-1 D L D L+1 D L+2 D L+S-1 ;

[0060] When reading data from RAM, the window function coefficients W0, W1, W2, ..., W are also read from RAM. L-1 The data and coefficients are multiplied by a multiplier and then fed into the FFT to obtain L frames of FFT data.

[0061] (5.3.4) The host computer plots each frame of FFT data into a spectrum diagram, and then displays each spectrum diagram in the frequency domain through the frequency domain display window of the host computer; in addition, the host computer overlays each frame of FFT data in the time axis direction, and after converting the amplitude value into color value, plots a time-frequency diagram and a time / frequency / amplitude three-dimensional stereo diagram, and then displays the time-frequency diagram in the time-frequency domain through the time-frequency domain display window of the host computer, and displays the time / frequency / amplitude three-dimensional stereo diagram in the time / frequency / amplitude three-dimensional stereo diagram through the time-frequency-amplitude three-dimensional display window;

[0062] In this embodiment, all results displayed in real time by the panoramic analysis are as follows: Figure 3 As shown, panoramic analysis can reveal the signal distribution across the entire bandwidth, but the frequency and time-frequency domain information of the signal has low resolution.

[0063] (5.4) Real-time display of detailed analysis;

[0064] (5.4.1) The multi-domain analysis data is split into two paths by the parallel splitter C. One path of multi-domain analysis data is input to mixer I, and the other path of multi-domain analysis data is input to mixer Q.

[0065] (5.4.2) An 80-channel parallel direct frequency synthesizer (DDS) generates 80 parallel sine signals and N parallel cosine signals. The 80 parallel cosine signals are then input to mixer I, and the 80 parallel sine signals are input to mixer Q.

[0066] In this embodiment, real-time mixing technology is required to process the high-speed sampling data from the front end. Figure 4 The structure of the real-time mixing technology is shown in the diagram. The mixing frequency of the frequency domain display window is set to 50MHz, the analysis bandwidth is set to 50MHz, the short-time Fourier transform (FFT) module length is set to 256, and the window function movement step is set to 16. Each channel of the input data is multiplied by the sine and cosine signals output by the DDS to obtain the mixing I and Q results for each channel.

[0067] (5.4.3) Mixer I mixes the multi-domain analysis data and 80 parallel cosine signals to obtain 80 parallel I data; the 80 parallel I data are split into two paths by parallel splitter D. One path is sent to parallel-to-serial conversion module C to be converted into serial I data; the other path is sent to parallel decimation filter structure for parallel decimation filtering to obtain serial decimated I data.

[0068] In this embodiment, in order to perform real-time processing of high-speed sampled data, parallel decimation filtering technology is required. The parallel decimation filtering structure consists of a parallel CIC filter and a parallel half-band filter, wherein, as... Figure 5 As shown, the parallel CIC filter consists of a cascaded parallel integrator, a parallel decimator, and a cascaded parallel comb. The parallel integrator and the parallel comb are cascaded in the same number of stages, which can be determined according to the stopband attenuation requirements of the design. The decimation number R = 40. After 80 parallel I data passes through the parallel CIC filter, 2 parallel I data are obtained.

[0069] like Figure 6 As shown, the structure of the parallel half-band filter includes parallel data splitting, an FIR filter, and delay and shifting. After the two parallel I data passes through the parallel half-band filter, serial I data is obtained.

[0070] Then, the serial I data and the serial decimated I data are selected for output through data selector A, and the output result is input to the serial decimation filter structure for serial decimation filtering to obtain the final serial I data.

[0071] In this embodiment, the serial decimation filter structure consists of a serial CIC filter and a serial half-band filter, such as... Figure 7 As shown, the serial CIC filter consists of a serial integrator, a serial decimator, and a serial comb. The serial integrator and the serial comb are cascaded to the same number of stages, which can be determined according to the stopband attenuation requirements of the design. The serial half-band filter is essentially a serial FIR filter, and the half-band filter coefficients can be determined according to the stopband attenuation requirements of the design.

[0072] (5.4.4) After mixing the multi-domain analysis data and 80 parallel sinusoidal signals, the mixer Q obtains 80 parallel Q data. The 80 parallel Q data are split into two paths by the parallel splitter E. One path is sent to the parallel-to-serial conversion module D to be converted into serial Q data. The other path is sent to the parallel decimation filter structure for parallel decimation filtering to obtain serial decimated Q data. Then, the serial Q data and the serial decimated Q data are selected by the data selector B, and the output result is input to the serial decimation filter structure for serial decimation filtering to obtain the final serial Q data.

[0073] (5.4.5) When the display mode of the digital oscilloscope is set to real-time display for detailed analysis, the data selector C selects serial data I and Q and stores them in the data buffer;

[0074] (5.4.6) Following steps (5.3.3) to (5.3.4), the short-time Fourier transform module reads serial I and Q data from the data buffer, processes and displays them; at the same time, the amplitude / phase / frequency calculation module reads serial I and Q data from the data buffer, calculates the amplitude / phase / frequency discrete sequence, plots the discrete sequence as amplitude-time curve, phase-time curve, and frequency-time curve, and then displays the modulation domain through the modulation domain display window of the host computer;

[0075] In this embodiment, all results of the detailed analysis are displayed in real time, such as Figure 8 As shown, detailed analysis reveals the signal distribution within a specific frequency band. The frequency domain display window allows observation of the range of signal frequency changes with high frequency resolution. The time-frequency domain display window reveals the pattern of frequency changes over time. The time / frequency / amplitude three-dimensional display window reveals the overall detailed changes in signal time, frequency, and amplitude. The modulation domain display window reveals the changes in amplitude and phase of the modulation signal over time, providing richer signal observation information.

[0076] Finally, after the rising edge of the next cycle of the trigger signal, return to step (4) to continue extracting the next set of multi-domain analysis data for processing and display.

[0077] Although the illustrative specific embodiments of the present invention have been described above to enable those skilled in the art to understand the invention, it should be understood that the invention is not limited to the scope of the specific embodiments. For those skilled in the art, various changes are obvious as long as they are within the spirit and scope of the invention as defined and determined by the appended claims, and all inventions utilizing the concept of the present invention are protected.

Claims

1. A method for multi-domain synchronous real-time analysis and display of complex signals in a digital oscilloscope, characterized in that, Includes the following steps: (1) Power on the digital oscilloscope, connect the signal to be measured, enable the write enable of the memory in the digital oscilloscope, and set the display mode of the digital oscilloscope: panoramic analysis real-time display or detailed analysis real-time display. (2) The measured signal is acquired through the acquisition system of the digital oscilloscope to obtain N parallel sampling data. Then, the N parallel sampling data is divided into two paths, one path is sent to the memory and the other path is sent to the trigger module. (3) In the trigger module, the parallel N-channel sampled data are processed by a parallel data comparator to obtain N-channel trigger comparison signals. Then, the N-channel trigger comparison signals are monitored. If any one of the trigger comparison signals is high, a trigger signal is generated and fed back to the memory. (4) When the memory detects the rising edge of the trigger signal, it records the location of the currently sampled data in the memory and uses it as a timestamp P. trig Then the memory uses timestamp P trig The calculation starts from the starting address, and the sampled data of length D is recorded as multi-domain analysis data, where D is the length of the time domain display window of the host computer; (5) Real-time synchronous display of multi-domain analysis data; (5.1) The host computer reads the multi-domain analysis data from the memory, and then splits it into two paths through the parallel splitter A. One path of multi-domain analysis data is processed by parallel-to-serial conversion, decimation, correction and interpolation, and then displayed in the time domain through the time domain display window of the host computer; the other path of multi-domain analysis data is sent to the multi-domain analysis module. (5.2) The multi-domain analysis data is split into two paths by the parallel splitter B. One path of multi-domain analysis data is sent to the panoramic analysis module and proceeds to step (5.3); the other path of multi-domain analysis data is sent to the detailed analysis module and proceeds to step (5.4). (5.3) Real-time display of panoramic analysis; (5.3.1) Multi-domain analysis data is converted into serial data by parallel-to-serial converter B; (5.3.2) When the display mode of the digital oscilloscope is set to panoramic analysis real-time display, the data selector C selects serial data to be stored in the data buffer; (5.3.3) The short-time Fourier transform module reads serial data from the data buffer and performs short-time Fourier transform to obtain multi-frame FFT data; (5.3.4) The host computer plots each frame of FFT data into a spectrum diagram, and then displays each spectrum diagram in the frequency domain through the frequency domain display window of the host computer; in addition, the host computer overlays each frame of FFT data in the time axis direction, and after converting the amplitude value into color value, plots a time-frequency diagram and a time / frequency / amplitude three-dimensional stereo diagram, and then displays the time-frequency diagram in the time-frequency domain through the time-frequency domain display window of the host computer, and displays the time / frequency / amplitude three-dimensional stereo diagram in the time / frequency / amplitude three-dimensional stereo diagram through the time-frequency-amplitude three-dimensional display window; (5.4) Real-time display of detailed analysis; (5.4.1) The multi-domain analysis data is split into two paths by the parallel splitter C. One path of multi-domain analysis data is input to mixer I, and the other path of multi-domain analysis data is input to mixer Q. (5.4.2) The N-channel parallel direct frequency synthesizer (DDS) generates N parallel sine signals and N parallel cosine signals. Then, the N parallel cosine signals are input to mixer I, and the N parallel sine signals are input to mixer Q. (5.4.3) Mixer I mixes the multi-domain analysis data and N parallel cosine signals to obtain N parallel I data; the N parallel I data are split into two paths by parallel splitter D. One path is sent to parallel-to-serial conversion module C to be converted into serial I data; the other path is sent to parallel decimation filter structure for parallel decimation filtering to obtain serial decimated I data; then the serial I data and serial decimated I data are selected by data selector A, and the output result is input to serial decimation filter structure for serial decimation filtering to obtain the final serial I data. (5.4.4) The mixer Q mixes the multi-domain analysis data and N parallel sinusoidal signals to obtain N parallel Q data. The N parallel Q data are split into two paths by the parallel splitter E. One path is sent to the parallel-to-serial conversion module D to be converted into serial Q data. The other path is sent to the parallel decimation filter structure for parallel decimation filtering to obtain serial decimated Q data. Then, the serial Q data and the serial decimated Q data are selected by the data selector B, and the output result is input to the serial decimation filter structure for serial decimation filtering to obtain the final serial Q data. (5.4.5) When the display mode of the digital oscilloscope is set to real-time display for detailed analysis, the data selector C selects serial I and Q data and stores them in the data buffer; (5.4.6) Following steps (5.3.3) to (5.3.4), the short-time Fourier transform module reads serial I and Q data from the data buffer, processes and displays them; at the same time, the amplitude / phase / frequency calculation module reads serial I and Q data from the data buffer, calculates the amplitude / phase / frequency discrete sequence, plots the discrete sequence as amplitude-time curve, phase-time curve, and frequency-time curve, and then displays the modulation domain through the modulation domain display window of the host computer.

2. The method for multi-domain synchronous real-time analysis and display of complex signals in a digital oscilloscope according to claim 1, characterized in that, The parallel decimation filter structure consists of a parallel CIC filter and a parallel half-band filter.

3. The method for multi-domain synchronous real-time analysis and display of complex signals in a digital oscilloscope according to claim 1, characterized in that, The serial decimation filter structure consists of a serial CIC filter and a serial half-band filter.

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