> -----Original Message----- > From: Bob McGwier [mailto:[EMAIL PROTECTED] > Sent: den 6 juni 2008 09:23 > To: Per Zetterberg > Cc: discuss-gnuradio@gnu.org; 'Per Zetterberg' > Subject: Re: [Discuss-gnuradio] OFDM results. > > In your sixteen QAM and other figures I see two effects. > > Notice just the slightest hint that arcs through the top four > constellation points in the 16 QAM is not straight. This > curvature is caused by nonlinearity. > > Your result almost surely can NOT be clock jitter. If you > had a lot of clock jitter, the pictures would look much > worse. Notice the dispersion gets larger as your proceed > away from the origin. This is almost surely phase noise in > some oscillator. > > Bob >
Thanks! New question: Would the phase noise get smaller in USRP2 where we can use an external reference, given that we use a high precision external reference ? _______________________________________________ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
