[hpsdr] DSP theory, interpreting IQ streams as audio, and way too much math - is this a good approach?

[Chris Albertson]

On Fri, Jun 22, 2012 at 7:24 PM, Erik Anderson
<erikba at odysseus.anderson.name> wrote:
> ***** High Performance Software Defined Radio Discussion List *****
>
>
> I think I've reached the point in my little programming exercise where I'm getting a really fast IQ stream flying at me that likely contains interesting radio data.  So now I'm trying to figure out what to do with it.  And of course I'm doing the stupid thing and trying to wade out and figure things out on my own and realizing that this isn't as easy as calling up your local FFT library and throwing everything at it to fix for you.

So you have decided NOT to use an FFT?    You can save a lot of CPU
cycles if you do dump the data stream into FFTW.

The reason is because there is this neat trick, if you take the FFT,
multiply that by an implies function and then take the inverse FFT you
have just applied any number of convolutions.  This pays off in a big
way if you want to do more with the data then just detect one USB
signal.

-- 

Chris Albertson
Redondo Beach, California

 1340427693.0