Impulse response function for non-stationary time domain signal

how to find the Impulse response function for non-stationary time domain signal?

I first wanted to find a frequncy response and then inverse fourier transform. I found freqz function and invfreqz but its for system.

I want for data.

[Nikhil Sonavane]

Impulse response is the output of a system when the input of the system is impulse signal. Hence, impulse response is defined for a system and not a signal. Can you rephrase your question and let me know what exactly you are looking for?

[Ramya Raman]

I have a output signal from an experiment. I understand if we have the input and output we can get the frequncy response and taking the IFFT will give us the impluse reponse of the system. However, I have the inputs only in statistical form.

Is there a way to get the frequncy response only with the output signal?

Answer 1

[Nikhil Sonavane]

The concept of frequency response from input and output by using convolution in time domain and multiplication in frequency domain is valid only in the case of LTI systems.