Benghazi University
Faculty of Engineering
Electrical and Electronics Engineering Department
Digital signal process
)EE414(
Report
Students Name: ‫ساجدة علي محمد ارعيض‬
Students Number: 30088
Date : [5/5/2025]
Experiment 1
Analog Signal:
x(t)=3cos⁡(2000πt)+5sin⁡(6000πt)+10cos⁡(12000πt)
Sampling Frequencies:
• Case 1: fs=12000Hz
• Case 2: fs=5000Hz
Code:
t = 0:1e-6:0.005;
x_t = 3*cos(2000*pi*t)
+ 5*sin(6000*pi*t)
+ 10*cos(12000*pi*t);
% Sampling at Fs = 12000 Hz
Fs1 = 12000;
n1 = 0:1/Fs1:0.005;
x_n1 = 3*cos(2000*pi*n1)
+ 5*sin(6000*pi*n1)
+ 10*cos(12000*pi*n1);
% Sampling at Fs = 5000 Hz
Fs2 = 5000;
n2 = 0:1/Fs2:0.005;
x_n2 = 3*cos(2000*pi*n2)
+ 5*sin(6000*pi*n2)
+ 10*cos(12000*pi*n2);
figure;
% Sampling with Fs = 12000 Hz (Discrete Time)
subplot(2,1,1);
plot(t, x_t, 'k:', 'LineWidth', 1); % Original signal (dotted)
hold on;
stem(n1, x_n1, 'b', 'filled', 'LineWidth', 1.5, 'MarkerSize', 4);
title('Discrete Time Signal (Fs = 12000 Hz)');
xlabel('Time (s)');
ylabel('Amplitude');
grid on;
legend('Analog Signal (x(t))', 'Sampled Signal (x[n])');
hold off;
% Sampling with Fs = 5000 Hz (Discrete Time)
subplot(2,1,2);
plot(t, x_t, 'k:', 'LineWidth', 1); % Original signal (dotted)
hold on;
stem(n2, x_n2, 'r', 'filled', 'LineWidth', 1.5, 'MarkerSize', 4);
title('Discrete Time Signal (Fs = 5000 Hz)');
xlabel('Time (s)');
ylabel('Amplitude');
grid on;
legend('Analog Signal (x(t))', 'Sampled Signal (x[n])');
hold off;
set(gcf, 'Position', [100, 100, 800, 600]); % [left, bottom, width, height]
Experiment 2
Analog Signal:
x(t)=8cos⁡(200πt)
Sampling Frequencies:
• Case 1: fs=400Hz
• Case 2: fs=150Hz
Code:
% Define the analog signal
t = 0:1e-5:0.05;
x_t = 8 * cos(200 * pi * t);
% Sampling at Fs = 400 Hz
Fs1 = 400;
n1 = 0:1/Fs1:0.05;
x_n1 = 8 * cos(200 * pi * n1);
% Sampling at Fs = 150 Hz
Fs2 = 150;
n2 = 0:1/Fs2:0.05;
x_n2 = 8 * cos(200 * pi * n2);
% Plotting the signals
figure;
% Sampling with Fs = 400 Hz
subplot(2,1,1);
plot(t, x_t, 'k:', 'LineWidth', 1); % Original signal as dotted line
hold on;
stem(n1, x_n1, 'b', 'filled', 'MarkerSize', 4);
title('x[n] with Fs = 400 Hz (Original signal as dotted line)');
xlabel('Time (s)');
ylabel('Amplitude');
grid on;
legend('Analog signal x(t)', 'Sampled signal x[n]');
hold off;
% Sampling with Fs = 150 Hz
subplot(2,1,2);
plot(t, x_t, 'k:', 'LineWidth', 1); % Original signal as dotted line
hold on;
stem(n2, x_n2, 'r', 'filled', 'MarkerSize', 4);
title('x[n] with Fs = 150 Hz (Original signal as dotted line)');
xlabel('Time (s)');
ylabel('Amplitude');
grid on;
legend('Analog signal x(t)', 'Sampled signal x[n]');
hold off;
% Adjust figure size for better visualization
set(gcf, 'Position', [100, 100, 800, 600]);