On 22 Sep., 18:22, robert bristow-johnson <r...@audioimagination.com>
wrote:
> On Sep 22, 12:21 pm, robert bristow-johnson
>
>
>
>
>
> <r...@audioimagination.com> wrote:
> > On Sep 22, 9:32 am, Ikaro <ikarosi...@hotmail.com> wrote:
>
> > > > 1) Where should I set frequency offset and phase noise value in the code?
> > > > Because I found that the above filter code doesn't contain that
> > > > information.
>
> > > There should not be any frequency offset. The noise spectra should
> > > cover all the sampled spectrum (0-fs/2).
>
> > or, as much of that spectrum as possible/practical/necessary.  you can
> > filter white noise into pink with a 3-pole, 3-zero filter over 10
> > octaves from 0.0009*Nyquist to 0.9*Nyquist within +/- 0.3 dB error.
>
> > > The noise phase value is random, uniformly distributed betwee -pi/2
> > > and pi/2.
> > > You should filter the white noise signal using the FILTFILT so that
> > > the IIR filter so that the filtered signal will have zero phase delay.
>
> > not true at all.  since the phase of the white noise signal going in
> > is totally random, whatever phase that the filter adds to it does not
> > matter.
>
> > r b-j
>
> forgot to add:  this pagehttp://www.firstpr.com.au/dsp/pink-noise/is
> a good one to look at.

Additionally, here is a nice bibliography on the subject:

http://www.nslij-genetics.org/wli/1fnoise/