%對輸入隨機序列進行16QAM調制
function [y1,y2]=sixteenQam_modulation(x)
%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;
z1=x(a);
z2=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
b=1:2:N/2;
temp1=z1(b);
temp2=z1(b+1);
y11=temp1*2+temp2;

temp1=z2(b);
temp2=z2(b+1);
y22=temp1*2+temp2;

%按照格雷碼的規則進行映射
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;