Chapter 12

The Discrete Fourier Transform and Fast Fourier Transform Algorithms

In This Chapter

arrow Looking at the DFT as uniformly spaced samples of the DTFT

arrow Working with the DFT/IDFT pair

arrow Exploring DFT theorems

arrow Implementing the fast Fourier transform algorithm

arrow Checking out an application example of transform domain filtering

Fourier’s name is associated with four different chapters of this book — nearly all the chapters in Part III. So what’s special about the discrete Fourier transform (DFT)? Computer computation! Under the right conditions the DFT returns a sample version of the discrete-time Fourier transform (DTFT) but using a systematic computer computation.

That’s right; the DFT allows you to move to and from the spectral representation of a signal with fast and efficient computation algorithms. You won’t find any integrals here! Complex number multiplication and addition is all there is to the mathematical definition of the DFT.

In this chapter, I introduce efficient methods ...

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