dapskmap_frequency_long.m

通信系统中的最新的分块差分调制技术的源码

function [z]=dapskmap_frequency_long(sequence,a,ncon,long);
% dpskmap16 将输入比特流映射到DAPSK的星座 16
% sequence输入比特流
% enc_comp 星座点坐标
maping8=[0 pi/4 pi*3/4 pi*2/4 pi*7/4 pi*6/4  pi pi*5/4];
maping16=[0 pi/8 3*pi/8 pi/4 7*pi/8 3*pi/4 pi/2 5*pi/8 15*pi/8 7*pi/4 3*pi/2 13*pi/8 pi 9*pi/8 11*pi/8  5*pi/4];
if ncon>16
    maping=maping16;
else
    maping=maping8;
end
    k=log2(ncon);
    
t=1;    
r=ones(1,long);
theta=zeros(1,long);
N=length(sequence);
% ****************************
 for i=1:k:N,
    index=0;
    for p=i:i+k-2
        index=2*index+sequence(p);
    end;
index=index+1;
theta1=mod(maping(index)+theta(t),2*pi);
                       if sequence(i+k-1)==0&r(t)==1;
                                r1=1;
                       elseif   sequence(i+k-1)==1&r(t)==1
                                 r1=a;
                       elseif   sequence(i+k-1)==0&r(t)==a
                                r1=a;
                       else
                                r1=1;
                       end
I_comp((i+k-1)/k,1)=r1*cos(theta1);
Q_comp((i+k-1)/k,2)=r1*sin(theta1);
theta(t)=theta1;
r(t)=r1;
t=t+1;
if  t>long
    t=t-long;
else
    t=t;
end

end
z=I_comp(:,1)+j*Q_comp(:,2);
%z=reshape(z1,1,Nu);