[Top][All Lists]

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: FFT time-shift/interpolation

From: Steve Thompson
Subject: Re: FFT time-shift/interpolation
Date: Thu, 16 Apr 2009 07:13:59 -0700


In the past, I've had luck with a so-called continuously variable digital
delay (CVDD) algorithm by Farrow:

  C. W. Farrow, ``A Continuously Variable Digital Delay Element,'' in
  Proceedings for the IEEE International Symposium on Circuits and Systems,
  pp. 2641--2645, 1988.

You can see how I use it here:
and more specifically, here:

I just did a search for "farrow matlab" and see this Farrow technique is
used quite a bit.

Good luck.


On Thu, Apr 16, 2009 at 5:13 AM, shivan <address@hidden> wrote:

Hi everybody, I trying to shift (circular) a real signal by delta, so I do :

a = [1:10] %as a test
b = ifft( fft(a) .* exp(-2*i*pi*[0:9]*delta/10))

so, yeah, that's cool. but I'd like to use a non-integer delta, like 0.2.
But of course I'll end up with b being an array with imaginary number.
I could interpolate to get more samples and only pick the on I need, but
it's unpractical for values like 0.3452.

would someone please have an idea?

View this message in context:
Sent from the Octave - General mailing list archive at

Help-octave mailing list

reply via email to

[Prev in Thread] Current Thread [Next in Thread]