EXIT chart.rar_Chart ldpc_LDPC_LDPC EXIT_LDPC EXIT chart_LDPC、EX

clc clear all % close all %% %%%%%%%%%%%%%%%%%%%%%%%%%%%%%% Inputs %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% n=1e5; %Code length rate=1/2; %design rate k=rate*n; %message length dv=3; %Variable node degree SNRdB=1.1; %SNR in decibel %% %%%%%%%%%%%%%%%%%%%%% Chennel LLR output (CLO) %%%%%%%%%%%%%%%%%%%%%%%%%%%% % x = 1-2*randint(1,n); SNR=10^(SNRdB/10); sigma2c=1/(2*rate*SNR); %sigma^2 of channel CLO=(2/sigma2c)*(ones(1,n)+sqrt(sigma2c)*randn(1,n)); %Chennel LLR output %% %%%%%%%%%%%%%%%%%%%%% a priori LLRs (APL) %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% %first we should find sigma values that produce I_A various values between %zero and one %I_A=I(X;A)=J(sigma) ==> sigma=J^-1(I_A) I_A=0:0.05:0.99; sigma=Jinv_s(I_A); %Jinv_s function finds the inverse values of J function %% %%%%%%%%%%%%%%%%%%%% Apply decoder (variable node) %%%%%%%%%%%%%%%%%%%%%%%% for ii=1:length(sigma) sigma2a=(sigma(ii))^2; APL=((sigma2a)/2) + sqrt(sigma2a)*randn(n,dv); %we should produce n*dv a priori values Ext=zeros(n,dv); for r=1:n for c=1:dv temp=APL(r,:); Ext(r,c)=CLO(r)+sum(temp)-temp(c); end end E=[]; for cc=1:dv E=[E;Ext(:,cc)]; %Convert the matrix Ext to vector E to apply the function MI end I_E(ii)=MI(E); %Finding Mutual Information end %% %%%%%%%%%%%%%%%%%%%%% Depict the results %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% I_E(end+1)=1;I_A(end+1)=1; plot(I_A,I_E,'LineWidth',1) axis([0 1 0 1]) hold on xlabel('I_A_,_V_N_D') ylabel('I_E_,_V_N_D') % legend(['Variable node EXIT function for d_v= ',num2str(dv)],4) title(['EXIT chart for SNR=',num2str(SNRdB),' dB and R=',num2str(rate)])