Design And Implementation For Time-frequency Analysis Function In Digital Oscilloscope

For a long time,the oscilloscope has been well known to many researchers for its special time-domain observation function.With the rapid development of electronic information industry,the development of analog oscilloscope to digital oscilloscope has not only brought about the improvement of measurement accuracy,waveform capture rate and other indicators,but also provided a variety of possibilities for the oscilloscope to integrate various advanced functions.On the platform of digital storage oscilloscope,the function of time-frequency analysis is added,which transforms the oscilloscope from a single time-domain observation instrument to an integrated multi-dimensional observation instrument in time-domain,frequency-domain and time-frequency joint domain.Because the acquisition module of the oscilloscope in front of the hardware still only has the ability to collect data in time domain,the analysis function in frequency domain and time-frequency domain can only be realized by processing the sampling data in time domain and then converting it into data in frequency domain and time-frequency domain.Based on the software and hardware platform of 20GSa/s sampling rate digital storage oscilloscope,this paper designs and implements the function of time-frequency analysis.The details are as follows:1.Frequency domain analysis: The sampling data in time domain are converted to the analysis data in frequency domain by using fast Fourier transform algorithm.Based on digital down-conversion technology,the fast Fourier transform algorithm is optimized to improve the frequency resolution.The realization of frequency cursor function.Realization of logarithmic and linear coordinate axes.2.Realization of Time-Frequency Analysis Algorithms: Analysis of Time-Frequency Resolution by Short-Time Fourier Transform and Wavelet Transform.Multithreading technology is used to design and optimize software functions.The algorithm of shorttime Fourier transform and wavelet transform is realized by Mixed programming based on MATLAB and C#.According to the digital characteristics of short-time Fourier transform,wavelet transform and time-domain sampling,frequency shift and time-base shift are set.3.Interface display and control function: function design and implementation of waterfall map and three-dimensional probability map,including management and mapping of color library,cursor function of waterfall map and three-dimensional probability map respectively,and efficiency optimization of drawing graphics.The optimization of software response mechanism.This topic uses the idea of object-oriented to program and debug the above functional modules on the.NET platform,realizes the time-frequency analysis function of digital oscilloscope,and tests and verifies the above functions.In the final test,the power of each module can run correctly and steadily.