estimate transfer function from power spectrum density

I have data of PSD with frequesncey and I want to estimate the Transfer function of the system, appreciate any suggestion

Answer 1

[Star Strider]

I would not use the PSD for this, since the Fourier transform (fft or pspectrum) are better.

If the System Identification Toolbox is available, begin with the idfrd function if the frequency response data are the only data available, and go from there. If the time domain data are available, start with iddata and proceed as described in the documentation. When the system is identified, use the compare function to see how well the model matches the data.

If the System Identificiation Toolbox is not available and the Signal Processing Toolbox is, use the invfreqz function to estimate the transfer function.

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