I have a funny issue with PFB clock sync tag propagation.
I'm using the corr_est block to detect the start of a burst. It works fine (at least when I have a decent-enough frequency lock). However, the PFB clock sync block shifts the tags to way before the burst, causing the following Costas loop to go off lock.
The first picture shows the tags as they're supposed to be:
Second shows how they are after PFB and Costas (and yes, I checked that it's the PFB which introduces the lag).
Scanning the mailing list shows that there were issues (supposedly fixed) with tags getting lost due to rate changes. I do not have that issue, all tags come through fine.
Has anyone encountered this before and is there a workaround?
Thanks in advance