[Top][All Lists]
[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: [Discuss-gnuradio] strange receiver behaviour with UHD
From: |
Per Zetterberg |
Subject: |
Re: [Discuss-gnuradio] strange receiver behaviour with UHD |
Date: |
Tue, 28 Sep 2010 15:53:00 +0200 |
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
> address@hidden 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