[PD] Combat aliasing!

[Matteo Sisti Sette]

Matteo Sisti Sette escribió:
> Charles Henry escribió:
>>> The interpolation, since it cannot be an ideal interpolation, may 
>>> introduce
>>> other noises or artifacts, not aliasing as far as I can see.
>>
>> There's two parts to it, aliasing (stopband) and non-flat frequency
>> response (passband). 
> 
> Well this seems o be a matter of terminology. I think you call 
> "aliasing" a wider class of artifacts than I was taught to call "aliasing".

Oh no, maybe not.
I read your explanation more carefully and of course, the 
non-perfectness of the interpolation process (i.e. its non-zero 
frequency response in the stop band) is responsible for the persistence 
of attenuated copies of the original spectrum at multiples of the 
original sampling rate, which then appear aliased into the passband when 
the signal is sampled again at a different rate.


This is what's going on when discontinuities in the interpolated signal 
cause noise at high frequencies, isn't it?

-- 
Matteo Sisti Sette
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