The frequency-domain representation of a signal reveals important signal characteristics that are difficult to analyze in the time domain. Spectral analysis lets you characterize the frequency content of a signal. Perform real-time spectral analysis of a dynamic signal using thespectrumAnalyzerobject in MATLAB^®and theSpectrum Analyzerblock in Simulink^®。频谱分析仪使用过滤器银行卫理公会教徒d or the Welch's method of averaging modified periodogram to compute the spectral data. Both these methods are FFT-based spectral estimation methods that make no assumptions about the input data and can be used with any kind of signal. For more information on the algorithm the spectrum analyzer uses, seeSpectral Analysis。In addition to viewing the spectrum, you can also view the spectrogram of the signal in the spectrum analyzer. For an example, seeView the Spectrogram Using Spectrum Analyzer。

If you want to acquire this data for post processing in MATLAB, callisNewDataReadyandgetSpectrumDataobject functions on the spectrum analyzer object. By calling these functions in the streaming loop, you can acquire the entire spectral data. In Simulink, to acquire the spectral data, create aSpectrumAnalyzerConfigurationobject and run thegetSpectrumDatafunction on this object. Note that in Simulink, you can acquire only the last frame of the spectral data shown on the spectrum analyzer.

Alternately, you can use thedsp.SpectrumEstimatorSystem object™ andSpectrum Estimatorblock to compute the power spectrum and acquire the spectral data for further processing. To view the spectral data computed by the spectrum estimator, use an array plot. For examples, seeEstimate the Power Spectrum in MATLABandEstimate the Power Spectrum in Simulink。