Follow me on Instagram:
https://instagram.com/shinton_seg?utm...

Follow me on LinkedIn:
  / shinton-george  

How to find Twiddle factor
   • Twiddle factor | Digital signal proce...  

Fast Fourier Transform (FFT)
The FFT may be defined as an algorithm for computing the DFT efficiently with reduced
number of calculations.
FFT are of two types
Decimation in-time (DIT) FFT algorithm and Decimation-in-frequency (DIF) FFT algorithm
The computation of 8-point DFT using radix-2 FFT involves three stages of computation.
Here N = 8 that is = 2 to the power 3 .
So there will be 3 stages
stage 1= four 2-point DFTs
stage 2= two 4-point DFTs
stage 3= 8-point DFT
From the results of four 2-point DFTs, two 4-point DFTs are obtained and from the results of two 4-point DFTs, the 8-point DFT is obtained.
00:00 time domain to frequency domain
00:40 write normal form
01:13 write bit reversed form
03:36 determine the number of stages
07:16 draw four 2 point DFT
07:55 put -1 in the base line
08:12 multiply all base line by twiddle factor
10:30 draw two 4 point DFT
11:04 put -1 in the base lines
11:20 put twiddle factor ahead of cross mark
14:42 draw one 8 point DFT
15:35 put -1 in last four base lines
16:35 multiply twiddle factor ahead of cross mark
20:26 write the sequence X(k)

butterfly diagram in dsp
dit fft 8 point