On 1/9/08, shyamnath gollakota <[EMAIL PROTECTED]> wrote: > Thanks a ton for the reply. My main concern is not that the frequency > offset is high enough but that it changes pretty often (every time I run > a new run) which makes it difficult for repeatability.
The frequency offset in the USRP is largely due to thermal transients associated with either power cycling the unit, or periods of on-off activity. > So is there a way in software where I can make sure that the frequency > offset is constant either by finely controlling the center frequency at > the tranmitter every time I run or is there some other way around this > problem? Frequency tracking/synchronization is often the most complex (read, fun :) part of receiver design. Depending on your modulation type, there are a variety of phase-locked loop architectures that can fine tune the center frequency of your signal. Simplified, you calculate an error value based on some property of your received signal, then use that to nudge the center frequency up or down until the error value goes to zero. -- Johnathan Corgan Corgan Enterprises LLC http://corganenterprises.com/ _______________________________________________ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
