On Fri, 14 May 2004, Roman Haefeli wrote:
hi
i had a discussion with a teacher today. the topic was the smallest delay-time possible. in his opinion one sample is the atom of signal and cannot be divided anymore. in my opinion it should be possible to get shorter delays than 1 samples with interpolation. my argument was: it should be possible to set the values of each sample so, that the resulting signal would be similar to a digitized analogue signal with a shorter than 1 sample delay.
It's certainly possible to get bandlimited fractional sample delays, using all pass filters. I don't remember if the minimum possible delay of the filter (if it can give a fractional delay less than one sample). But this is the technique used to tune physical waveguide models.
Try searching the web for "fractional" "waveguide" "allpass" or the like.
Larry Troxler