Birla Institute of Technology Mesra
Jaipur
Digital Signal Processing
Kushagra gupta
BTECH/25164/19
EEE 5th sem
Q: Object: Compute N point DFT & IDFT of the length N sequence using MATLAB
2.a DFT
2.b IDFT
Solution:
Code of Matlab:%DFT and IDFT
clc;
clear;
close;
x=input('Enter the Input Seq');
N=length(x);
disp(N);
y=zeros(1,N);
for k=0:N-1
for n=0:N-1
y(k+1)=y(k+1)+x(n+1)*exp((-2*i*pi*k*n)/N);
end
end
magnitude=abs(y);
subplot(3,2,1);
stem(magnitude);
xlabel('frequency');
ylabel('Magnitude');
title('magnitude part ');
z=phase(y);
subplot(3,2,2);
stem(z);
xlabel('Frequency');
ylabel('Phase');
title('Phase part');
N=length(y);
m=zeros(1,N);
for n=0:N-1
for k=0:N-1
m(n+1)=m(n+1)+((1/N)*(y(k+1)*exp(((i)*2*pi*k*n)/N)));
end
end
% IDFT
disp('m=')
disp(m)
subplot(3,2,3);
stem(m);
xlabel('frequency');
ylabel('Magnitude');
title('magnitude part of IDFT');
n=phase(m);
subplot(3,2,4);
stem(n);
xlabel('Frequency');
ylabel('Phase');
title('Phase part of IDFT');