%matlab code for digital modulation(ask, fsk and psk)
pi=3.14;
f=5;
f2=10;
phi=pi;

x=[1 0 1 1 0];
nx=size(x,2);

i=1;
while i<nx+1
     t = i:0.001:i+1;
    if x(i)==1
       ask=sin(2*pi*f*t);
       fsk=sin(2*pi*f*t);
       psk=sin(2*pi*f*t);
    else
        ask=0;
        fsk=sin(2*pi*f2*t);
        psk=sin(2*pi*f*t+phi);
    end
    subplot(3,1,1);
    plot(t,ask);
    hold on;
    grid on;
    axis([1 10 -2 2]);
  
    subplot(3,1,2);
    plot(t,fsk);
    hold on;
    grid on;
    axis([1 10 -2 2]);
  
    subplot(3,1,3);
    plot(t,psk);
    hold on;
    grid on;
    axis([1 10 -2 2]);
  
    i=i+1;
end