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From: "Frank " <allinone_2003@yahoo.com.hk>
Newsgroups: comp.soft-sys.matlab
Subject: Re: IDTFT
Date: Mon, 21 Jun 2010 16:25:09 +0000 (UTC)
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Hi Wayne,

Thanks for your advice. In fact, I want to ask a conceptual question.

DTFT:
X(e^(j w/K)) = sum_{n=0}^{N-1}x(n) e^{-jwn/K}......................(1)

IDTFT:
x(p) = integrate_{- pi}^{pi} X(e^(j w/K)) e^{jwp}dw/2/pi
       = sum_{n=0}^{N-1}x(n) sinc(p-n/K);......................................(2)

However, when I compute the FFT of (2), it is different from (1).

Can you solve this problem?

Thanks a lot.

Frank