Amplitude and Frequency Shift Keying Modulation simulation using MatLab

afk_modulation.m

%% Variables Definition
fps  = 400;
data = [1 0 0 1 1 0 1 0 1 1];
A    = 4;
f    = 8;
f0   = 2;

%% Create the signal of "Information"
info_signal = gen_INFO(data, fps);

%% Create the time array of time
time = gen_TIME(fps, length(info_signal)/fps);

%% Create the signal of "Carrier"
carrier_signal = gen_CARRIER(f, A, fps, length(data));
carrier_signal_0 = gen_CARRIER(f0, A, fps, length(data));

%% Create ASK modulated signal
ask_signal = gen_ASK(info_signal, carrier_signal);

%% Create FSK modulated signal
fsk_signal = gen_FSK(info_signal, carrier_signal, carrier_signal_0);

%% Plotting to graph
subplot(5,1,1); plot(time, info_signal); title('Information');
subplot(5,1,2); plot(time, carrier_signal); title('Carrier');
subplot(5,1,3); plot(time, carrier_signal_0); title('Carrier 0 in FSK');
subplot(5,1,4); plot(time, ask_signal); title('ASK modulation');
subplot(5,1,5); plot(time, fsk_signal); title('FSK modulation');

%% Function: create time
function time = gen_TIME(fps, max_time)
    N = fps * max_time;
    for i = 1:N
        time(i) = i/fps;
    end
end

%% Function: create information signal
function signal = gen_INFO(data, fps)
    N = length(data);
    for i = 1:N
        for j = 1:fps
            signal((i-1) * fps + j) = data(i);
        end
    end
end

%% Function: create carrier signal
function signal = gen_CARRIER(f, A, fps, time_max)
    N = fps * time_max;
    for i = 1:N
        signal(i) = A * sin(2 * pi * f * i/fps);
    end
end

%% Function: create ASK modulated signal
function signal = gen_ASK(info_signal, carrier_signal)
    N = length(info_signal);
    for i = 1:N
        if info_signal(i) == 1
            signal(i) = info_signal(i) * carrier_signal(i);
        else
            signal(i) = 0;
        end
    end
end

%% Function: create FSK modulated signal
function signal = gen_FSK(info_signal, carrier_signal_1, carrier_signal_0)
    N = length(info_signal);
    for i = 1:N
        if info_signal(i) == 1
            signal(i) = carrier_signal_1(i);
        else
            signal(i) = carrier_signal_0(i);
        end
    end
end