Research On Time-Frequency Analysis Of Digital Signals And Design Of The Software Applied To Analyze

As a powerful tool for analyzing non-stationary signals, Time-Frequency Analysis(TFA) has been a hot spot of modern signal research in recent years and got more and more attentions. Time-frequency analysis method provides the joint distribution of a time domain and frequency domain. It clearly describes that how the frequency of signal varies with time.In this paper, the theories of three time-frequency algorithms have been analyzed and researched. The features of three algorithms and differences between them have been obtained by Matlab software, and C code of three algorithms developed.Based on time-frequency algorithms, we have designed software of analyzing digital signal spectrum with Visual Studio 2005 as a development tool.The software processes the signal through the mode of Digital Data Converter and of extracting and then analyzes the signal in time domain, frequency domain and modulation domain; the results are displayed by graphical style.The software realizes the spectrum measurement and analysis of digital signal.Compared with the Scanning Spectrum Analyzer(SPA), the software can get signals seamlessly in block mode. Signals are got and stored in memory, and then processed. It overcomes the problem that the high-frequency signal may be missed in SPA when the signals have a section of rapid changes.The tests in the data acquisition system show that precision and data analysis capabilities of the software have reached the project's design requirements, with a high practical value.