Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Homework Help: MATLAB Plotting DTFT

  1. Dec 9, 2012 #1
    1. The problem statement, all variables and given/known data
    x[n] = Ʃ ck * δ(n-k), from k = -N to N. Plot the DTFT as a function of the number of terms N. This is a finite sum.


    2. Relevant equations

    The equation for the DTFT of a signal, which is Ʃ x[n] * e-j*2∏*∅*n, from n = -∞ to +∞

    3. The attempt at a solution
    I have nothing.... something like
    N = 50;
    ck = 1;


    X = [];
    phi = 1/(2*pi);

    for n = -1000:1:1000
    sum = 0;
    for k = -N:1:N
    sum = sum + dirac(n-k);
    end
    X = [X sum*exp(-1i*2*phi*n)];
    end


    n = -1000:1:1000;
    plot(n, X);

    But this is obviously wrong. I don't know how to compute the DTFT for a signal of a finite length like that, much less plot it using MATLAB!
     
  2. jcsd
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook

Can you offer guidance or do you also need help?
Draft saved Draft deleted