inverse fft from pmtm results

hello

I tried inverse fft from pmtm results.

but, time-series obtained from ifft is not same with original signal.

x0; %original time series

pxx; % pmtm results

inverse_signal= ifft(pxx, length(x0))

how i get the time-series from pmtm results?

[Star Strider]

That is not possible.

The pmtm returns the power spectral density of your time-domain signal, so you lose the phase information. Without a way to reconstruct the imaginary component, you cannot do the inversion.