Module 9 :
Numerical Relaying II : DSP Perspective
Lecture 33 :
Discrete Fourier Transform
33.1
Motivation (contd..)
Now,
where
AS is integer, then
Note that we have used the following geometric series expression
Thus, RHS in (6) is equal to
We see that equation (6) defines the inverse transformation if we choose ;
Thus, N-point DFT and IDFT for samples are defined as follows.
is integer, then 
;
are defined as follows. 
where m = 0, ........., N - 1 
