9 Jan
2007
9 Jan
'07
10:47 p.m.
Frank Brickle wrote:
Phil Karn wrote:
I was going to model phase noise as 1/f^2, but Bob pointed out that the integral of that expression bounded at zero (DC) is undefined. So we need another, more realistic model of oscillator phase noise if we're going to compute its effect on digital demodulation.
Typically you only take a model like this down to about 1Hz. Below 1 Hz it can be considered flat or even zero. We don't much care about the phase noise below 1 Hz since the symbol rates are so much higher than this.
Matt