MATLAB Code
clc;
clear all;
close all;
amplitude = 1; % Amplitude of the sine wave
frequency = 10; % Frequency of the sine wave in Hertz
duration = 1; % Duration of the signal in seconds
Fs = 10000; % Sampling frequency
% Time vector
t = 0:1/Fs:duration;
% Generate the sine wave signal
sinusoidal_signal = amplitude * sin(2*pi*frequency*t) + amplitude*2 * cos(2*pi*500*t);
% Plot the sine wave signal
figure;
plot(t, sinusoidal_signal, 'b-', 'LineWidth', 2);
title('Sinusoidal Signal');
xlabel('Time (seconds)');
ylabel('Amplitude');
grid on;
figure()
%demdulated
d=sinusoidal_signal;
filter=fir1(200, 10/(Fs/2), 'low');
original_t_signal=conv(filter,d);
t1=0:1/(length(original_t_signal)-1):1;
plot(t1,original_t_signal);
title('demodulated signal');
clear all;
close all;
amplitude = 1; % Amplitude of the sine wave
frequency = 10; % Frequency of the sine wave in Hertz
duration = 1; % Duration of the signal in seconds
Fs = 10000; % Sampling frequency
% Time vector
t = 0:1/Fs:duration;
% Generate the sine wave signal
sinusoidal_signal = amplitude * sin(2*pi*frequency*t) + amplitude*2 * cos(2*pi*500*t);
% Plot the sine wave signal
figure;
plot(t, sinusoidal_signal, 'b-', 'LineWidth', 2);
title('Sinusoidal Signal');
xlabel('Time (seconds)');
ylabel('Amplitude');
grid on;
figure()
%demdulated
d=sinusoidal_signal;
filter=fir1(200, 10/(Fs/2), 'low');
original_t_signal=conv(filter,d);
t1=0:1/(length(original_t_signal)-1):1;
plot(t1,original_t_signal);
title('demodulated signal');
Output
Fig: sin(2*pi*10*t) + 2cos(2*pi*500*t)
After Applying a Low-Pass filter which cut-off frequency is 10Hz,
we get this
MATLAB Code for High-Pass Filter
% Define or generate a sample signal
Fs = 1000; % Sampling frequency
t = 0:1/Fs:1; % Time vector
f_signal = 50; % Frequency of the signal
signal = sin(2*pi*f_signal*t);
% Design a high-pass filter
cutoff_frequency = 10; % Cutoff frequency in Hz
filter_order = 200; % Filter order
highpass_filter = fir1(filter_order, cutoff_frequency/(Fs/2), 'high');
% Apply the high-pass filter to the signal
filtered_signal = filter(highpass_filter, 1, signal);
% Plot the original and filtered signals
figure;
subplot(2,1,1);
plot(t, signal);
title('Original Signal');
xlabel('Time');
ylabel('Amplitude');
subplot(2,1,2);
plot(t, filtered_signal);
title('High-pass Filtered Signal');
xlabel('Time');
ylabel('Amplitude');
% Add a legend
legend('Original Signal', 'Filtered Signal');
% Show the plot
grid on;
Fs = 1000; % Sampling frequency
t = 0:1/Fs:1; % Time vector
f_signal = 50; % Frequency of the signal
signal = sin(2*pi*f_signal*t);
% Design a high-pass filter
cutoff_frequency = 10; % Cutoff frequency in Hz
filter_order = 200; % Filter order
highpass_filter = fir1(filter_order, cutoff_frequency/(Fs/2), 'high');
% Apply the high-pass filter to the signal
filtered_signal = filter(highpass_filter, 1, signal);
% Plot the original and filtered signals
figure;
subplot(2,1,1);
plot(t, signal);
title('Original Signal');
xlabel('Time');
ylabel('Amplitude');
subplot(2,1,2);
plot(t, filtered_signal);
title('High-pass Filtered Signal');
xlabel('Time');
ylabel('Amplitude');
% Add a legend
legend('Original Signal', 'Filtered Signal');
% Show the plot
grid on;
Output (when cut-off frequency is 10 Hz and original signal is set to 50 Hz)
Output (when cut-off frequency is 60 Hz and original signal is set to 50 Hz)
Copy the MATLAB Code from here
For Low-pass filter