GNURadio/USRP stream tag execution not as expected

[Nicolas Buhr]

Hi everyone,

I already posted this to stackoverflow, but maybe somebody here can help me as well.

I’m working with a USRP B210/X310 and I’m trying to send a frame with containing some payload, with synchronization sequences before and after the payload. For interesting measurements bit error rate measurements, I want to get a low SNR for the payload. Since I need a much better SNR for more synchronization, I’m trying to send the synchronization sequence with a high gain, while sending the payload with a much lower gain.

Trying to implement this I encountered some unexpected behavior while using the tagged stream commands for the GNURadio block. So I went back and made the most simple setup, I could imagine.

The results and the actual problem can be seen in the screenshots in my stackoverflow post:

https://stackoverflow.com/questions/75869595/gnuradio-usrp-stream-tag-execution-not-as-expected

Any ideas, where to look for/how to remove the error?

Thanks in advance,

Nicolas Buhr