Okay, it looks like pll_carriertracking_cc might help me do what I want.
I’ll see if I can get it working.
Thanks for your responses!
— On Fri, 8/7/09, Bob McGwier wrote:
From: Bob McGwier
Subject: Re: [Discuss-gnuradio] Tracking a Carrier Frequency
To: “Don L.”
Date: Friday, August 7, 2009, 1:54 AM
The FFT divides the frequency range into bins.Â While you can do some
computation based on the window function you use and how much power is
in adjacent bins based on this knowledge and get a refined offset,Â from
your proposal that sounds like it might be a step or two down the road
for you rather than your first step.Â The gist of this is that the FFT
will not be any more accurate than the bin width allows.
A better plan is to allow the FFT to “get you close” , and then use the
FFT bin center as the initial condition for a PLL, and then use the
actual phase locked loop based carrier routines with a noise bandwidth
smaller than the bin width in the FFT.Â This will refine the estimate of
the frequency nicely by using phase lock.
Don L. wrote:
seems to me this would be a common problem, and there would already be a
Â Â Â Â
Â Â Â
– (Co)Author: DttSP, Quiktrak, PowerSDR, GnuRadio Member: ARRL, AMSAT,
AMSAT-DL, TAPR, Packrats,
NJQRP, QRP ARCI, QCWA, FRC.
“You don’t need to see the whole staircase, just
take the first step.”, MLK.