After learning DFT,our next experiment was Fast Fourier Transform(FFT). We were asked to take a N input sequence. I took 8 input sequence on which FFT was performed. The code was written in c++ programming language.FFT performs 12 complex multiplications, 24 complex additions, 48 real multiplications and 72 real additions. After calculating FFT we were asked to calculate inverse FFT(IFFT) to check whether we get the same input sequence again. The speed of operation in FFT increases as compared to that of DFT. The Operations are carried out parallely in FFT.
Number of computations required are less, thus speed increases.
ReplyDeleteIts advantageous using FFT methods for analyzing the signals because it takes less number of steps for execution and hence the simplification rate increases
DeleteIts advantageous using FFT methods for analyzing the signals because it takes less number of steps for execution and hence the simplification rate increases
ReplyDeleteYes what Nikhil has written is right. This is why FFT is preferred over DFT.
ReplyDeletehow we calculate total real multiplication for FFT?
ReplyDeleteWe can calculate it by, Nlog(N)
Deletewhere N is the point of FFT.
DFT results are periodic because twiddle factor is periodic with period = N
ReplyDelete