Hi,
On 03/21/2016 10:52 PM, Attila Kinali wrote:
Good evening
On Sun, 20 Mar 2016 22:33:15 +0100
Magnus Danielson <[email protected]> wrote:
As you read the appendixes of ITU-T Rec. G.823, G.824 and G.825 they
will not give very detailed information, but hints. The flicker noise
model comes from Jim Barnes and Chuck Greenhalls PTTI 19 article "Large
Sample Simulation of Flicker Noise".
So far I have seen three approaches to 1/f^a simulation:
* filter in the time domain
* filter in the frequency domain
* simulate a random process with the right properties
Barnes&Greenhall[1], Park&Muhammad&Roy[2] on which Brooker&Inggs[3]
is based on fall into the first category.
Kasdin[4] and Ashby[5] falls into category two (Kasdin also gives a nice
overview of the problem space and the solutions applied there).
From the third category, i've sofar only read Milotti[6].
Chuck Greenhall have a nice overview of methods for flicker noise, and
goes in to some depth on it.
If this simulation approach is sufficient for either of your efforts, or
not, depends on what you try to capture. For instance, the oscillators
performance have been idealized in assuming fully linear EFC, fully
linear integrator of the crystal, assuming noise profile etc. This may
or may not be sufficient. Inherent lowpass filtering may be important or
not.
The modeling of the EFC and temperature dependence is orthogonal to the
noise modeling, AFAIK. And if I understand the physical properties of
a crystal, resp. the oscillator correctly, they can be modeled completely
independent without degrading the accuracy. Of course, noise on the EFC
signal will have an influence on the crystal noise, and this noise can
be of 1/f^a type itself as well.
Depending on the tau of interest, temperature variations may or may not
affect your plots.
Noise on EFC will be filtered, and then integrated.
Cheers,
Magnus
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