Timeline for Linear Phase Filters and FFT

6 events

when toggle format	what		by	license	comment
Jun 21, 2021 at 7:33	comment	added	Dan Boschen		@OverLordGoldDragon A unit sample is a Sinc sampled at all its zero crossings, but that makes for a poor filter (it is an all pass). But yes, not realizable to the same extent that we also cannot realize in practice brick-wall filters with zero delay. The more delay we can tolerate, the closer we can approximate a brick-wall filter, so equally the more we can approximate a Sinc (with tails below our quantization level of concern). Still you have that delay you have to accept to be causal.
Jun 21, 2021 at 3:56	comment	added	OverLordGoldDragon		Not unless the data is convergent at sufficient rate, I figure. But we'd much sooner run out of data before reaching sinc's float epsilon. If we can acceptably zero the missing data, compute would take ages (10^16 or 10^32 long kernel), and even then we trust so many add-multiplies are accurate. (Yet still, what if convergence in L2 sense is acceptable...)
Jun 21, 2021 at 3:43	comment	added	OverLordGoldDragon		Are we sure sinc isn't realizable? I'm not conclusive but seems this logic applies, difference being sinc is L1 divergent from any tail point to infinity. Might make a Q&A sometime.
Jun 21, 2021 at 2:01	history	edited	Dan Boschen	CC BY-SA 4.0	added 1 character in body
Jun 18, 2021 at 3:32	history	edited	Dan Boschen	CC BY-SA 4.0	added 180 characters in body
Jun 18, 2021 at 3:26	history	answered	Dan Boschen	CC BY-SA 4.0