Discrete Fourier Transform




 This was the great experience of learning Digital Signal Processing Laboratory, the aim was to perform Discrete Fourier Transform .in this lab session I have developed a function in C program on Linux terminal to perform the DFT of N-point signal where N was taken from the user (4/8). Then I performed the DFT of 4 point signal and 8 point signal and plotted the Magnitude spectrum. DFT gives output in a frequency domain, DFT spectrum is also discrete spectrum and it is approximated.DFT coefficients are defined as W=2*pi*k/N, it gives periodic results.
         Also,  I have done some more operation, I increased the length of the input signal by zero padding and then obtained the DFT of the signal after result analysis I found that as the length of signal increases by zero padding frequency spacing decreases, approximation error decreases and Resolution of the frequency spectrum increases.Also, expansion of the signal in time domain gives compressed frequency spectrum.I did the computation of complex and real multiplications and additions.

Comments

  1. Amol28 April 2017 at 02:38

    Total number of complex multiplication is given by N^2.

    ReplyDelete
    Replies
    1. Unknown28 April 2017 at 09:31

      yes and total number of real multiplication is 4*N^2 because for 1 complex multiplication requires 4 real multiplications

      Delete
  2. Unknown28 April 2017 at 04:48

    DFT is the frequency sampling of DTFT

    ReplyDelete
    Replies
    1. Unknown28 April 2017 at 09:36

      Yes it is sampled with frequency spacing of 2pi/N where N is the number of points

      Delete
  3. Aniket kharche28 April 2017 at 09:41

    expansion in time domain gives compression in DFT.

    ReplyDelete
  4. Aniket kharche28 April 2017 at 09:41

    DFT results are periodic

    ReplyDelete
    Replies
    1. Unknown28 April 2017 at 10:04

      Yes because twiddle factor is periodic with factor N

      Delete
  5. Unknown3 May 2017 at 12:21

    Please read my other blogs also and do comment ,like and share

    ReplyDelete

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