Re: GSM spectrum: Invisible 200kHz carriers?

You might also try playing with kalibrate
http://thre.at/kalibrate
it will scan for GSM base stations and use the results to determine
the current local frequency error in your USRP. If you have an
independent means of determining this error frequency, and compare
this with the results of kalibrate, it would pretty much nail the
identification question.

Some tips

  1. The proper USRP / DBSRX gain setting is important
  2. The gain setting and the frequency error may change if you
    move to a different frequency band…
  3. You have to manually specify the proper USRP clock frequency to
    kalibrate (unless you’ve modified the hardware clock)

Max