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Measurements >> Phase Noise and Jitter Measurements >> Cyclostationary noise characterisation
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Message started by designer_dude on Jul 27^th, 2016, 5:14pm

Title: Cyclostationary noise characterisation
Post by designer_dude on Jul 27^th, 2016, 5:14pm

Dear all,

I have a basic question on how cyclostationary noise is characterized/plotted. In Ken Kundert's tutorial on cyclostationary noise, we see the following plot attached.

What does the PSD plotted represent? How is it related to the autocorrelation of the cyclostationary noise, which is a function of 2 variables!

Title: Re: Cyclostationary noise characterisation
Post by Ken Kundert on Jul 27^th, 2016, 10:13pm

The yellow curve on the bottom graph represents the time-average noise power. It is the noise power averaged over a cycle.

-Ken

Title: Re: Cyclostationary noise characterisation
Post by designer_dude on Aug 1^st, 2016, 3:24pm

Hi Kent,

Would you be able to point to a proof of the above statement?

In particular, I'm interested in derivations of the following transfer functions from the 2 variable autocorrelation R_yy(t_1, t_2):

1. What is the sampled noise spectrum where sampling is done @ PSS periodicity in terms of R_yy(t_1, t_2)? My hunch is this noise is stationary because sampling removes the cyclostationarity.
2. What is the time-averaged (over PSS period) noise spectrum in terms of R_yy?

I have a hard time finding explicit derivations in the literature for the following, although they should be straightforward. Textbook references are helpful too, thanks!