Fast Discrete Fourier Transform (FFT)

Not a new transform.  Only an alternative algorithm to compute the DFT.  Time relationship:

Figure20.gif (1206 bytes)

FFT performs computation "in place" -> requires less temporary storage.

 

FFT routines usually require data sequence lengths that are a power of 2 (64, 256, 512, 1024, etc...)

- need to apply "Zero padding"

 

Figure21.gif (3680 bytes)

 

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