Monday, 13 March 2017

LAB2:-Discrete Fourier Transform

The aim of this experiment was to perform Discrete Fourier Transform(DFT) of a DT signal. We executed a function in C to perform DFT of an N point signal by providing length of the input signal as one of its arguments. Multiplications and additions of complex terms were done separately by considering only their coefficients. The results obtained were plotted in the form of a magnitude spectrum(Magnitude vs frequency).It was observed that DFT results are periodic,inverse-DFT converges and DFT of an expanded signal results on compression of magnitude spectrum.     

6 comments:

  1. As the value of N increases the resolution of the spectrum increases.

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  2. Yes compression would result in increase of resolution

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  3. Separate multiplication and addition of complex terms. Could you elaborate that?

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    Replies
    1. If (A+iB)(C+iD) is to be performed,then the real part would be
      (AC-BD) and imaginary part would be (AD+BC).In this way only coefficients are multiplied and added.

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  4. DFT is computationally slow method

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    Replies
    1. Yes the number of real and complex multiplications and additions for the samed order is higher when compared to FFT.

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