Re: [Discuss-gnuradio] Weird behavior of the correlate_and_sync block

[Andy Walls]

On Mon, 2015-03-30 at 09:03 -0700, Richard Bell wrote:

>  The github block you linked is in working order then?

It works for me.

But of course, per the GPL,
"[...] is distributed in the hope that it will be useful,
 but WITHOUT ANY WARRANTY; without even the implied warranty of
 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE [...]"

:)

>  Is there an example or documentation or can you explain how the
> matched filter should be implemented on yours?

"If you rebuild GNURadio with these patches, you can look at the example
test_corr_and_sync.grc file, that is in that pull request, for
guidance."

Specifically pay attention to the 'Modulate Vector' block; which lets
you specify a GNURadio modulator to run, a preamble to feed the
modulator, and a post filter; used to build the sample sequence which is
the matched filter sample sequence.  The new correlate and sync block
handles time reversal of the sample sequence you give to it. 
(Although it doesn't if you update the matched filter sometime later
while the block is running - sorry 1 bug that was not critical enough
for me to fix).

The 'Modulate Vector' block might not be in mainline GNURadio, so you'll
have to pick that up from that pull request too.  You could always
"manually" build the sample sequence for the matched filter in MatLab or
Python and paste it into GNURadio as well.

-Andy

> 
> Thanks,
> 
> Rich