Wednesday, 15 March 2017

Discrete Fourier Transform

Discrete Fourier Transform is the frequency sampled version of DTFT. To calculate DFT, the input sequence was assumed to be periodic. DFT for input length N=4 and N=8 was calculated. Output of DFT is periodic and it repeats after N values.Using Inverse DFT the input sequence was verified. Magnitude spectrum for N=4 and N=8 was plotted. It was found that increasing the number of inputs through zero padding increases the resolution of the magnitude spectrum.

7 comments:

  1. How is Dft the frequeny sampled version of DTFT?

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    1. DTFT is a continuous signal and sampling this signal gives us DFT. X(k) is obtained by replacing w with 2*pi*k/N in X(w).

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  2. Is DFT computationally very efficient?

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    Replies
    1. DFT is not computationally efficient and so we use Fast Fourier Transform for signal processing which has higher computational efficiency

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