# How to simulate (in matlab or c) power spectrum of random brownian noise signal?

I have a semi random noise signal, it does have some periodicity however.

I can estimate the power spectrum (of the blue signal, I thought that it would be more clear, because white noise is flat, but I digress)

How could I generate a noise signal from a power spectrum?

Brownian noise estimation is not the same as estimating from a power spectrum because of the 'sine wave' noise in the spectra, I would like to capture that.

• – MBaz
Commented Feb 29, 2020 at 0:03
• Yeah, I guess my problem is how do I get from a PSD (which I have) to FIR or IIR Commented Feb 29, 2020 at 5:33
• I am trying to find a way to do this, but it would help to have some details. Making $1/f^2$ noise is no problem, but what exactly are the top two figures showing? The upper one seems to have a red trace under the blue trace. And what is the noisy sine wave? Is it supposed to be there or is it an an interference of some sort? Is the PSD for the third figure, with that little hump corresponding to the sine wave?
– Ed V
Commented Feb 29, 2020 at 14:54
• @VoltageSpike Shouldn't you mention that in your question? Also, what is is Brownian noise related to your question? I'd like to ask you to edit your question to add more clarity.
– MBaz
Commented Feb 29, 2020 at 15:43
• I would like to reproduce the blue signal Commented Mar 1, 2020 at 6:54