Hi, I am working on an OOK receiver but am having some problems with the squelch.
I wrote a script with the following flow graph:
USRP.source_c -> complex_to_mag -> add_const_ff( -const ) -> binary_slicer_fb -> file_sink
This works fine, but I would like to have some sort of discrimination for when there is no signal. I looked into adding a pwr_squelch_cc block after the source but this led to a lot of buffer overruns as the processing increased. I am attempting to receive a bandwidth of 16 MHz using 8-bit samples so any more processing I add can make a difference. The bandwidth is important as I am trying to maximize the data rates it can handle.
There is also the option of checking after the fact and counting the number of samples that are zero. i.e. if there are x number of 0's then stop writing to file and wait for another 1 to come through. Is there anything implemented for this or would I have to write my own block?
If you have any ideas or suggestions of what I should take into account (i.e. alpha and ramp for squelch) then please let me know. My goal is to basically have a variable dwell time after a valid signal that will turn off after a certain delay.
Thanks,
Dan