Table 2 Signal values of the bottom half in Fig. 17
From: Canonic FFT flow graphs for real-valued even/odd symmetric inputs
Position | Input | After 1st stage | After 2nd stage | Before 3rd stage |
|---|---|---|---|---|
9th | x[1] | x[1]+x[7] | x[1]+x[7]+x[5]+x[3] | x[1]+x[7]+x[5]+x[3] |
10th | x[7] | x[1]−x[7] | x[1]−x[7] | x[1]−x[7] |
11th | x[5] | x[5]+x[3] | x[1]+x[7]−x[5]−x[3] | x[1]+x[7]−x[5]−x[3] |
12th | x[3] | x[5]−x[3] | (x[5]−x[3])(−j) | (x[5]−x[3])(−j) |
13th | x[3] | x[3]+x[5] | x[1]+x[7]+x[5]+x[3] | x[1]+x[7]+x[5]+x[3] |
14th | x[5] | x[3]−x[5] | x[3]−x[5] | \(\frac {\sqrt {2}}{2}(x[3]-x[5]-x[7]+x[1])\) |
15th | x[7] | x[7]+x[1] | x[3]+x[5]−x[1]−x[7] | (x[3]+x[5]−x[1]−x[7])(−j) |
16th | x[1] | x[7]−x[1] | (x[7]−x[1])(−j) | \(\frac {\sqrt {2}}{2}(-x[3]+x[5]-x[7]+x[1])j\) |