利用蒙特卡算法仿真二进制双极性基带通信系统

主程序：SNRindB1=0:1:12
SNRindB2=0:0.01:12;
for i=1:length(SNRindB1) 

 smld_err_prb(i)=exa038_Fun_doublePe(SNRindB1(i));
end
semilogy(SNRindB1,smld_err_prb,'r*');
for i=1:length(SNRindB2)
    SNR=10^(SNRindB2(i)/10);
    theo_err_prb(i)=(1/2)*erfc(sqrt(SNR/2));
end
hold on
semilogy(SNRindB2,theo_err_prb);
grid on

子程序：

function [p]=exa038_Fun_doublePe(snr_in_dB)
E=1;
SNR=10^(snr_in_dB/10);
sgma=E/sqrt(SNR);
N=10000;
disource=(sign(rand(1,N)-0.5)+1)/2;
numoferr=0;
for i=1:length(disource)
    if disource(i)==1
        r=E+randn*sgma;
    else
        r=-E+randn*sgma;
    end
    if(r>0)
        decis=1;
    else
        decis=0;
    end
    if(decis~=disource(i))
        numoferr=numoferr+1;
    end
end
p=numoferr/N;