Re: Symbol timing estimator block and CPM modulations

[Andy Walls]

On Sun, 2020-06-28 at 16:31 -0500, Alex Roberts wrote:
> Andy, 
> 
> I had a copy of an old flowgraph that you posted on the mailing list
> a long while back (
> https://lists.gnu.org/archive/html/discuss-gnuradio/2016-03/msg00735.html
> ). This is what initially confused me on what to pass in as gmsk
> symbols to corr_est block as it has strictly real values.
> 
> I modified it to mux in the preamble that's in the octave code with a
> random source. I also modified the octave code to match the samples
> per symbol of the flowgraph (10) and generated the modulated symbols
> for the corr_est block. The corr_est block does indeed
> perform conjugation and reversal of the symbols, so I used the "h_iq"
> value from the octave code as the modulated symbols since it has not
> been conjugated or reversed. I'm not getting corr_est tags. 

On that flowgraph, set your threshold on the corr_est block to 0.23.

BTW, that preamble has horrible correlation properties.


> Thanks,Alex.

-Andy