Lab7 (Signal & System) Instructor: Anan Osothsilp Date: 20 Feb 07 Due Date 03 April 07

Anan OsothsilpPage 1 Lab7 Date: 03 April 07 Objective: Learn how to use for create GUI for fourier transform technique

Anan OsothsilpPage 2 Lab7 Instruction: Step 1: Review Lab5 Fourier series Step 2: Review Lab6 For GUI creation Step 3: create GUI program for Fourier transform in Exercise 1 Date: 03 April 07

Anan OsothsilpPage 3 Lab7 Exercise 1: Create GUI for interactive Fourier series (vary frequency & N) Frequency N points Magnitude Spectrum Phase Spectrum f(t) = 5*sin(2*pi*f*t) Date: 03 April 07

Anan OsothsilpPage 4 Lab7 Exercise 1: Create GUI for interactive Fourier series (vary frequency & N) In your Lab report also make conclusion about the effect of 1. Frequency parameter for actual waveform and frequency spectrum 2. N point parameter for actual waveform and frequency spectrum Date: 03 April 07

Anan OsothsilpPage 5 Lab7 Fourier series code Date: 03 April 07 for n = [1 3 5 ]; %alternative for n = 1:2:N sum =sum+ (-2/(n*pi))*(5*sin(2*pi*n*t)); end

Anan OsothsilpPage 6 Lab7 Frequency Spectrum of Fourier series Matlab code x = [ ]; y = 2*x; stem(x,y); N = 10; Wo = f*pi; for n = [-N:-1,1:N], Dn = 2/(j*n*Wo); stem(n*Wo,abs(Dn)) hold on; pause(1); end Generate magnitude spectrum of signal Date: 03 April 07

Anan OsothsilpPage 7 Lab7 N = 10; Wo = f*pi; for n = [-N:-1, 1:N], Dn = 2/(j*n*Wo); stem(n*Wo,angle(Dn)*180/pi) hold on; end Generate phase spectrum of signal Date: 03 April 07