On Tue, 2010-09-28 at 15:15 +0200, Patrik Eliardsson wrote: > Dear List, > > We have made a test program using a source and a file sink (see fg.jpg) where > we are receiving a fixed number of samples (with UHD and USRP2 and WBX-card) > from an AWGN-generator (constant power -19dB). If we plot the abs value of > the received signal we always see a "spike" in the 10 first samples (see > fig1) before the abs value settles to a more expected value. Sometimes > (seldom) there is no "spike" but the result is still not as expected, the > received data starts at a higher level and slopes down during a quite long > time before settling to a stable level (see fig 2). > > Have we missed something or why does this "spike" occur? Is there some > initialization time in the hardware that we need to take into consideration > before we start to receive samples (recv) after setting all parameters? > > Br, > Patrik > _______________________________________________ Discuss-gnuradio mailing list > [email protected] > http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
I see also some kind of transient spur the 1000-2000 first samples when using XCVR2450 (I have mentioned this before on the list :-). Next time I have a basic dB connected I will check if this behavior is observed also there. I always discard the 1000-2000 samples to avoid the problem. BR/ Per _______________________________________________ Discuss-gnuradio mailing list [email protected] http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
