qdpskcd.m

对ASK调制解调进行了仿真,包括程序仿真和模型仿真

function y=qdpskcd(x,Kmod);
if nargin<2; Kmod=1; end;
if nargin<1; x=str2cod('MATKAB'); end;
T=[0 3; 1 2];
n=length(x); y(1:2)=x(1:2);a=T(y(1)+1,y(2)+1);
for i=3:2:n-1;
    xn=x(i:i+1)+1; b=T(xn(1),x(2));
    if Kmod ==1;
        [y(i),y(i+1)]=find(T ==rem(b+a,4));
        a=T(y(i), y(i+1));
    elseif Kmod ==2;
        if b<a; b=b+4; end;
        [y(i),y(i+1)]=find(T ==rem(b-a,4));
        a=rem(b,4); a=a+(a ==0) *4;
    end;
    y(i:i+1) =y(i: i+1);
end;