Data Acquisition And Processing Based On Digital Storage Oscilloscope

Virtual instruments are the product of the penetration of computer hardware, software and bus technology to other areas, full use of the computer unique intelligent features such as computing, storage, playback, call,display and document management, also making the specialized functions of traditional instruments and panel control software-based, and it has been widely used in the test and measurement technology and automation field.In this paper, the completed virtual oscilloscope can analysis on the time domain and frequency domain on the basis of waveform generated.Also studied the data acquisition through USB interface, realizing a lot of subtle signal analysis and processing of signals collected, greatly improved the traditional digital storage oscilloscopes.This Paper firstly designed a complete data acquisition program in accordance with protocol process according to the communication protocol of the target device, to achieve the correct communication between the computer and storage devices. Then transfer data to a computer through the USB interface. This paper designed a virtual oscilloscope panel on Lab Windows platform, after the classified and analysis on the various types of data information includes device model, the control word size, resolution size, etc.to plot and observe which part of the data on a virtual oscilloscope, carried out analysis of time domain and frequency domain. Which focuses on the process of various communication signals including a phase-modulated signal QPSK, amplitude-modulated signal QAM and frequency- modulated signal MSK. Respectively, analysis from the time domain and frequency domain, the time domain analysis mainly in terms of the autocorrelation function, constellation diagrams and eye diagrams conducted. Frequency domain analysis mainly in terms of the spectrum transformed, spectrum refinement, power spectral density other aspects of the analysis and processing. Meanwhile, the designed virtual oscilloscope can also perform basic functions of storage oscilloscope, such as producing a baseband signal, shaping filter, through a unified approach quadrature modulation and demodulation of the modulation process to common communication signals orthogonal processing, ultimately demodulation, also research on adaptive demodulation. Finally, give a study and summary of the navigation signals ILS signal,and combined with Matlab for the main indicators of ILS signal, heading angle detection, Slip angle detection.In this paper the storage oscilloscope data acquisition by C language, in the data processing part after the design of the virtual oscilloscope, it is on Lab Windows platform. For which individual situation algorithm is very complex, calling Matlab to draw the waveform. Finally fully realized the function of the digital memory oscilloscope.