Module 9 : Numerical Relaying II : DSP Perspective

Lecture 35 : Computation of Phasor from Discrete Fourier Transform

35.3

Full Cycle Recursive DFT (contd..)

   
 

The computation for can be visualized from the following pair wise multiplication and add sequence enclosed in red brackets in the fig 35.1.
 
 
Now, to compute , we add one new sample . Computation of from is shown by pairing with in the green boundary. It is now obvious, that
 
. Since, for m - an integer. Thus,
    (12)
  Similarly, for sine component, we have    
 

  (13)
 
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