how to find normalized centered instantaneous of amplitude,phase and frequency using matlab code?

I am trying to work on digital modulation classification using ANN the first step is to extract feature i have difficult on finding normalized centered instantaneous amplitude,phase and frequency to find the maximum value of Power Spectral Density (PSD) of normalized-centered instantaneous amplitude,phase and frequency using matlab can any one help me

[Raúl Maldonado]

Hello, how was your search? I have the same problem.

Answer 1

[MULI]

Hi @edu ab,

For digital modulation classification using ANN, you can extract key features like instantaneous amplitude, phase, and frequency by following these steps:

• You can use the "Hilbert transform" to compute the instantaneous amplitude and phase of your signal. You can also use the "instfreq" function to calculate instantaneous frequency directly: https://www.mathworks.com/help/signal/ug/hilbert-transform-and-instantaneous-frequency.html
• Normalize each of the extracted features (amplitude, phase, and frequency) by removing the mean and dividing by the standard deviation.
• Use the "pwelch" function to compute the PSD of each normalized feature. This gives you insight into the spectral distribution of each characteristic: https://www.mathworks.com/help/signal/ref/pwelch.html
• From each PSD curve (amplitude, phase, frequency), extract the maximum value. These values serve as compact features for your ANN model.

You can also refer to the below answer where similar query is addressed:

https://www.mathworks.com/matlabcentral/answers/403856-how-to-find-normalized-centered-instantaneous-of-amplitude-phase-and-frequency-using-matlab-code