tongyuan.m

实现2ASK

        clear all
        x=[1 0 0 1 0 1 1 0 1 1]
        grid=200;
        t=0:1/grid:length(x);
        for i=1:length(x)       
          if(x(i)==1)             
            for j=1:grid         
               y((i-1)*grid+j)=1;
            end
          else
            for j=1:grid      
               y((i-1)*grid+j)=0;
      end;end;end
     y=[y,x(i)];
     w1=2*pi;w2=4*pi;A=1;
     c1t=A*sin(w1*t);c2t=A*sin(w2*t);
s=menu('通信原理','2ASK','2PSK','2FSK','MSK','GRAY')
switch s
 case 1,scolor='2ASK';
     subplot(3,1,1) 
     plot(t,y),title('01系列码s(t)')
     subplot(3,1,2)
     plot(t,c1t),title('正弦载波信号')
     subplot(3,1,3)
     e1t=c1t.*y;
     plot(t,e1t),title('2ASK输出波形')
 case 2,scolor='2PSK';
     subplot(2,1,1) 
     plot(t,y),title('01系列码s(t)')
     for i=1:length(y);
         if(y(i)==1)
             y(i)=-1;
         else y(i)=1;
      end;end
      subplot(2,1,2) 
      e1t=c1t.*y;
      plot(t,e1t),title('2PSK输出波形')
  case 3,scolor='2FSK';
     subplot(2,2,1)
     plot(t,c1t),title('正弦载波信号1')
     subplot(2,2,3)
     plot(t,c2t),title('正弦载波信号2')
     subplot(2,2,2) 
     plot(t,y),title('01系列码s(t)')
     for i=1:length(y);
         if(y(i)==1)
            e1t(i)=c1t(i);
         else e1t(i)=c2t(i);
      end;end
     subplot(2,2,4)
     plot(t,e1t),title('2FSK输出波形')
  case 4,scolor='MSK';
  case 5,scolor='GRAY';
      M=input('请输入四位二进制数：');
      for i=4:-1:1
          N1(i)=rem(M,10);
          M=fix(M/10);
      end
      for i=4:-1:2
        N2(i)=N1(i-1); 
      end
        N2(1)=0;
        N=xor(N1,N2)
end