FOSP Tutorial - 1
Yash Jadhav - 2020400012
Durga Warrier - 2020400069
Topic : Derivation for DIT-FFT Flowgraph for N = 4.
We divide the DFT equation into two parts based on n where the first part is for
even and second is for odd.
Forming the equation of X[k] as a combination of the odd and even
sequences.
Substituting x(2r) = a(r) and x(2r+1) = b(r)
Two blocks of N/2 point DFT - One for even and One for odd.
Replace the 2 pt. DFT blocks by FFT Flowgraph for N=2
Finally we get the flowgraph to find DFT of x[n] i.e X[k] using DIT-FFT
Flowgraph for N = 4.
Solved Example:
Let x[n] = {1,2,3,4}
To find: X[k] i.e DFT of x[n] using the FFT Flowgraph method.
Solution:
X[k] = {10, -2+2j, -2, -2-2j }
Thus we find the DFT of a signal using the DIT-FFT Flowgraph for
N=4.