EE342: MATLAB M-FILE DEMONSTRATING EFFECTS OF DISCRETE-TIME TRUNCATION ON DISCRETE-FOURIER TRANSFORM

%
% Filename: example16.m
%
% Description: M-file for investigating the effect of discrete-time
%              signal truncation on the DFT.
%

N = [8 11 14 16];           % number of data points in truncated DT
                            % signal
                            
for m = 1:4,                % compute DFT of four truncated signals
  n  = 0:N(m)-1;            % DT values for truncated signal
  x  = cos(pi*n/2);         % truncated DT signal
  Xk = dft(x);              % compute DFT of truncated DT signal
  subplot(2,2,m);           % plot magnitude spectrum
  stem(n*2*pi/N(m),abs(Xk),'filled');
  xlabel('\Omega '); ylabel('|X_k|');
  ttl = ['DFT of cos(\pin/2) for n=0,..,',num2str(N(m)-1)];
  title(ttl);
end;