Re: [Discuss-gnuradio] Parallel Port Interface - why quadrature samples?

[Chris Albertson]

Someone who knows more please add to this....

Practically, I think what you gain is two independent samples
of the signal.  In theory this will boost your S/N by a factor
of 1.41 or sqrt(2).  

Matmatically you are sampling the data as complex numbers.
complex FFTs are Matmatically "nicer" in that they are
symetric and so forth.  But what do engineers care bout
"matmatically nicer"?


--- Stephan Olbrich <address@hidden> wrote:
> Hi,
> 
> > Going back to my soundcard suggestion, you could buy a 96ks/s
> stereo soundcard
> > for less than $100 these days.  Take your input signal, mix it
> (multiply) by a
> > 48 kHz sine and cosine wave, lowpass filter those 2 outputs, and
> feed to the
> > soundcard stereo inputs.  You'll have sampled the spectrum from 0
> to 96kHz at 24
> > bits per sample.
> Can someone give me a hint what's the point in mixing with a sine and
> cosine and sample both signals? 
> 
> Stephan
> 
> 
> 
> 
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=====
Chris Albertson
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