flâneur

FFT: An 8 Input Butterfly

alwayslearn.com · 125 words · saved by 1 readers

N Log N = 8 Log (8) = 24. A straight DFT has N*N multiplies, or 8*8 = 64 multiplies. That's a pretty good savings for a small sample. The savings are over 100 times for N = 1024, and this increases as the number of samples increases.

A DFT and FFT TUTORIAL A DFT is a "Discrete Fourier Transform". An FFT is a "Fast Fourier Transform". An FFT is a DFT, but is much faster for calculations. The whole point of the FFT is speed in calculating a DFT. Here is an example of an 8 input butterfly: An The 8 input butterfly diagram has 12 2-input butterflies and thus 12*2 = 24 multiplies. N Log N = 8 Log (8) = 24. A straight DFT has N*N multiplies, or 8*8 = 64 multiplies. That's a pretty good savings for a small sample. The savings are over 100 times for N = 1024, and this increases as the number of samples increases. You can…

saved by

related reading