Fast Fourier Transform matlab code

AIM:

To verify Fast Fourier Transform.

EQUIPMENTS:

Operating System         – Windows XP

Constructor                  - Simulator

Software                      - CCStudio 3 & MATLAB 7.5

THEORY:

The Fast Fourier Transform is useful to map the time-domain sequence into a continuous function of a frequency variable. The FFT of a sequence {x(n)} of length N is given by a complex-valued sequence X(k).

PROGRAM:

%fast fourier transform

clc;

clear all;

close all;

tic;

x=input('enter the sequence');

n=input('enter the length of fft');

%compute fft

disp('fourier transformed signal');

X=fft(x,n)

subplot(1,2,1);stem(x);

title('i/p signal');

xlabel('n --->');

ylabel('x(n) -->');grid;

subplot(1,2,2);stem(X);

title('fft of i/p x(n) is:');

xlabel('Real axis --->');

ylabel('Imaginary axis -->');grid;

RESULT: