bertest.m

采用 DVB反向链路（DVB-RCS）标准中的双二元Turbo码matlab仿真程序和仿真结果。支持1/2和1/3码率。支持MAP

%双二元Turbo码的顶层误码测试程序
clear
clc
% snr_db=0:0.2:2;
snr_db=2.0;
snr=10.^(snr_db/10);
N=212;   %帧长,对应于ATM包
IntTimes=8; %迭代次数

for k=1:length(snr)
    InVar=1.0/snr(k);  %方差
%     InVar=1.5/snr(k);  %方差
    ErrorNum=0; %误码个数
    ErrorFrameNum=0;    %误帧个数
    FrameNum=0; %帧数
    if snr_db(k)<=.5
        MaxFrameErrorNum=400;
    elseif snr_db(k)<=1.0
        MaxFrameErrorNum=200;
    elseif snr_db(k)<=1.5
        MaxFrameErrorNum=100;
    elseif snr_db(k)<=1.75
        MaxFrameErrorNum=40;
    else
        MaxFrameErrorNum=15;
    end
    while ErrorFrameNum<MaxFrameErrorNum
        sourse=randint(1,2*N);
        %编码
        [VecOutA,VecOutB,Sc1,Sc2]=DouBinTurboEncode(sourse,N,1/2);
%         [VecOutA,VecOutB,Sc1,Sc2]=DouBinTurboEncode(sourse,N,1/3);
        %通过信道
        Ar=VecOutA(1:N)+sqrt(InVar)*randn(1,N);
        Yr1=VecOutA(N+1:2*N)+sqrt(InVar)*randn(1,N);
        Wr1=zeros(1,N);
%         Wr1=VecOutA(2*N+1:3*N)+sqrt(InVar)*randn(1,N);
        Br=VecOutB(1:N)+sqrt(InVar)*randn(1,N);
        Yr2=VecOutB(N+1:2*N)+sqrt(InVar)*randn(1,N);
        Wr2=zeros(1,N);
%         Wr2=VecOutB(2*N+1:3*N)+sqrt(InVar)*randn(1,N);
        %解码
        decoded=DouBinTurboDecode(Ar,Br,Wr1,Yr1,Wr2,Yr2,N,IntTimes,InVar,Sc1,Sc2);
        %统计误码
        [Num ber0]=biterr(sourse,decoded);
        if Num~=0
            ErrorFrameNum=ErrorFrameNum+1;
        end
        ErrorNum=ErrorNum+Num;
        FrameNum=FrameNum+1;
        if mod(FrameNum,10)==0
            sprintf('snr=%fdB,%d Frames transmitted, %d bit errors,%d frame errors\n',snr_db(k),FrameNum,ErrorNum,ErrorFrameNum)
        end
    end
    ber(k)=ErrorNum/(FrameNum*N*2);
    fer(k)=ErrorFrameNum/FrameNum;
    sprintf('Finally,snr=%fdB,%d Frames transmitted, %d bit errors,%d frame errors,bit error ratio is %f\n',snr_db(k),FrameNum,ErrorNum,ErrorFrameNum,ber(k))
end
% semilogy(snr_db,ber)