Re: [Discuss-gnuradio] OOK reception

[Dan Halperin]

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On Oct 9, 2008, at 8:39 AM, Dan wrote:

> 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.

If you're doing complex_to_mag anyway, why not use that output for  
squelching instead of a pwr_squelch_cc ? The squelch algorithm is  
pretty simple.

Also, complex_to_mag has a sqrt in it which it looks like your flow  
graph doesn't need. All the following blocks would work just as well  
in the mag^2 domain. So maybe you should do that too.

- -Dan
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