May I know how to find Time frequency power spectrogram of a signal?

1. What is time-frequency spectrogram?
2. How do you find the frequency spectrum of a signal?
3. How do you find the power spectrum of a signal in Matlab?

What is time-frequency spectrogram?

A spectrogram is a visual way of representing the signal strength, or “loudness”, of a signal over time at various frequencies present in a particular waveform. Not only can one see whether there is more or less energy at, for example, 2 Hz vs 10 Hz, but one can also see how energy levels vary over time.

How do you find the frequency spectrum of a signal?

Frequency spectra of PPG signals are commonly calculated using the Fourier transform. The Fourier transform uses sinusoidal waves to map the contents of the signal to the frequency domain (Semmlow and Griffel, 2014). Sine waves can be expressed in terms of their amplitude, frequency, and phase.

How do you find the power spectrum of a signal in Matlab?

p = pspectrum( x , fs ) returns the power spectrum of a vector or matrix signal sampled at a rate fs . p = pspectrum( x , t ) returns the power spectrum of a vector or matrix signal sampled at the time instants specified in t .