turbo_ic.m

B3g_phase2_C语言_Matlab程序及说明

function [x_intf,x_sigma,Add_x_mean, Add_x_var]=Turbo_IC(x_rake,Rou,Mask,Noise_variance,x_mean,x_variance,SubslotData_length,Path_number,Det_intl_table,nIter)


% Gray coded 16-QAM mapping vector
MapMatrix16QAM = [-1-j -1-3*j -1+j -1+3*j -3-j -3-3*j -3+j -3+3*j 1-j 1-3*j 1+j 1+3*j 3-j 3-3*j 3+j 3+3*j];
MapMatrix16QAM = MapMatrix16QAM/sqrt(10);

[M,N]=size(Mask); L=N/M;
Mask2=abs(Mask.^2);

 variance=sum(vec2mat(sum(Mask2),M))+Rou*Noise_variance;
[Rou_sorted,Order]=sort((Rou.^2)./(variance+0.001));
Order=Order(end:-1:1);

% [Rou_sorted,Order]=sort(Rou);
% Order=Order(end:-1:1);
x_mean0=x_mean;
x_variance0=x_variance;

for t=1:nIter
    for mm=1:M
        m=Order(mm);
        Mask_m=Mask(:,m:M:end);
        Mask2_m=Mask2(:,m:M:end);

        for n=1:SubslotData_length 
%             n=Det_intl_table(nn);
            x_intf(m,n)=x_rake(m,n)-sum(sum(x_mean0(:,n+(0:L-1)).*Mask_m));

            x_sigma(m,n)=abs(sum(sum(x_variance0(:,n+(0:L-1)).*Mask2_m))+Rou(m)*Noise_variance+0.001);

            P =exp(-abs(x_intf(m,n)-Rou(m)*MapMatrix16QAM).^2/x_sigma(m,n))/abs(sum(exp(-abs(x_intf(m,n)-Rou(m)*MapMatrix16QAM).^2/x_sigma(m,n)))+0.001);

            x_mean0(m,Path_number-1+n)=P*MapMatrix16QAM.';
            x_variance0(m,Path_number-1+n)=P*abs(MapMatrix16QAM.^2)'-abs(x_mean0(m,Path_number-1+n))^2;   
        end
    end
end

Add_x_mean = x_mean0(:,end-2*Path_number+3:end-Path_number+1);
Add_x_var  = x_variance0(:,end-2*Path_number+3:end-Path_number+1);