I can control the signal transmitted in the ISM channel; so, I know
the time when there is a signal to be detected in the channel. During
first hours the USRP detects the signal giving me a value of around 40
but after some hours such a detected signal decreases up to roughly 10
and it does not change anymore regardless of the signal transmitted in
ISM channel. Only if I kill the process running the
script and execute it again, the USRP starts to detect again the 40 db
value. The signal to be detected in the ISM channel is always the same.
anyone tell me which is the problem?
Oh, you were talking about the daughterboard itself. No guarantees
but the schematics are all available. I think there was a recent
discussion about this on the list. What I was saying specifically, was
that there is no AGC in the USRP motherboards/FPGA. Daughterboards are
separate, but in general, I don;t think they have AGC. The WBX and some
others, for instance, use fixed gain amplifiers with a variable
to control power.
Try to print the samples received. Check if after some moment the
start to repeat.
I had some problems with that when I implemented my energy and waveform
detection blocks (based on the title you used in the post, probably you
what they are). After some debugging, I figured that that problem was
the value I was returning in the work function.