Re: Software PLL (SPLL)

Ron N. wrote:
> Tim Wescott wrote:
> 
>>Implementing a PLL in software uses the same basic theory as
>>implementing a PLL in hardware -- you compare your synthesized signal to
>>a reference, generate a phase difference, then servo the frequency of
>>your synthesized signal to your reference.
> 
> 
> Why?  Isn't a software PLL just a forward interpolator.  Why not just
> estimate (statistical, FFT, phase vocoder or otherwise) the frequency,
> phase, derivatives of phase, etc.; generate a forward interpolation of
> the input reference using that information, and call that the output of
> the PLL NCO?  Recalculate periodically (every sample if the compute
> power is available).
> 
> 
> rhn A.T nicholson d.0.t C-o-M
> 

yuck!

you would have to work quite very to match, let alone beat, the 
performance you can get from a software PLL, requiring negligible 
computational overhead.

swatting flies with Howitzers often causes more problems than it solves.

Cheers
Terry