hes@ecsvax.UUCP (11/03/85)
FTD%MIT-OZ@MIT-MC.ARPA ("David D. Story") posted:
... If
you have noisy lines (and remember that this is recent history before
all the line conditioning and that's where Bell put the data phones)
the 3400 protocol is much better (cleaner).
Bell works on a feedback filter while Vadic works onharmonics.
The Bell filter had to let some noise in their frequency range pass
while the Vadic doesn't won't and never will.
-------------
Could some explain this further? I didn't think it was possible to
filter out *all* noise from a signal. I know that some
methods of noise eilimination work better than others (does "works
on harmonics" mean some kind of phase locked loop?) but I would be
very surprised if any (analog) method could get rid of all noise.
--henry schaffer n c state univ