From DTFT to FTD

  • The FT operates on a discrete-time signal. However, when we use a continuous frequency, we lose the digital advantage.

If we want to calculate the DTFT using a calculator, we encounter difficulties :

  • Calculating the TF requires an infinite number of measurement points x(n) (not always possible).

  • The calculator cannot calculate a DTFT (since f varies continuously) ⇒ a finite number of frequency points, The solution is the Discrete Fourier Transform (DFT).