function [y1,y2]=Qam_modulation(x)
%QAM_modulation
%對產生的二進制序列進行QAM調制
    %=====首先進行串并轉換，將原二進制序列轉換成兩路信號
N=length(x);
a=1:2:N;
y1=x(a);
y2=x(a+1);
    %=====分別對兩路信號進行QPSK調制
          %======對兩路信號分別進行2－4電平變換
a=1:2:N/2;
temp1=y1(a);
temp2=y1(a+1);
y11=temp1*2+temp2;
temp1=y2(a);
temp2=y2(a+1);
y22=temp1*2+temp2;
          %=======對兩路信號分別進行相位調制
a=1:N/4;
y1=(y11*2-1-4)*1.*cos(2*pi*a);
y2=(y22*2-1-4)*1.*cos(2*pi*a);
y1(find(y11==0))=-3;
y1(find(y11==1))=-1;
y1(find(y11==3))=1;
y1(find(y11==2))=3;
y2(find(y22==0))=-3;
y2(find(y22==1))=-1;
y2(find(y22==3))=1;
y2(find(y22==2))=3;