Hi, all!
I am working on a proof of concept of a radar system for my doctoral
thesis. I recently installed the great gr-pdu and gr-timing utilities
from Sandia Labs and I am trying to develop a little application with
GNURadio Companion (GRC), based on a USRP N200 system.
I essentially want to use the rising edges of a pulsed signal to
generate another signal. For this purpose, first the trigger signal is
sampled with a USRP-Source block, then is threshold detected by means
of a "Threshold trigger" block and finally, a message with a "Tag
message trigger" block is generated. The output of this last block
feeds a "PDU to Bursts" block which enters a USRP-Sink.
I have checked with a "Tag Debug" that the threshold detection and
message generation are both working fine. At the output of the "PDU to
Bursts" block, each burst is tagged with the "tx_sob" and "tx_eob"
tags. The problem arises when those burts enter the USRP-Sink. As far
as I've read, this blocks transmits all burts sequentially ignoring
the time separation that should be between them. Please, take into
account that the trigger pulses are not equally separated in time, so
I must transmit one burst with each received pulse.
I think the issue is that no "tx_time" tags are being generated and
added to each burst. I wonder if anyone have the same explanation for
this issue, and hopefully, if anyone can guide me on how can I inject
those "tx_time" tags properly in my stream with GRC.
Any help will be appreciated!
Regards,
José
