After some thinking: Could this be phase noise? If it is, which oscillator is at fault? The TVRX frontend? The max. phase jitter equals roughly 100 Hz.
On Fri, Mar 31, 2006 at 05:08:54PM +0200, Jens Elsner wrote: > Good morning, > > I sampled a local DAB radio station at 225.648 MHz, decimation factor 32 > with the USRP/tvrx. > > DAB is using COFDM with pi/4-DPSK on 1536 subcarriers (see www.etsi.com, > standard > EN300401 for details). I wrote some Matlab code to demodulate the > signal. The data is resampled from 2 MHz (URSP) to 2.048 MHz (DAB Standard). > A frequency offset is compensated manually. > > It works so far, only one problem arises: The I/Q signal diagram jumps > and jitters randomly by up to pi/8. What could be the problem? I am > absolutely clueless - the frequency offset is compensated perfectly. > > My ultimate goal is to implement OFDM de/modulation and a DAB receiver > in gnuradio. > > Greetings, > Jens > > > > _______________________________________________ > Discuss-gnuradio mailing list > Discuss-gnuradio@gnu.org > http://lists.gnu.org/mailman/listinfo/discuss-gnuradio _______________________________________________ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
