plot.asv

AWGN信道下高斯噪声干扰下GALILEO编码译码系统性能仿真

clc 
clear all
tic
SNR_in_DB=-4:0.5:10;
snr_in_DB=-4:0.5:2.5



for i=1:length(SNR_in_DB),
   snr=10^(SNR_in_DB(i)/10);%计算理想误码率
   x=sqrt(2*snr);
   y(i)=(1/2)*erfc(x/sqrt(2));
   
   E=1;
   sgma=sqrt((E/snr)/2);%噪声方差
   N=1;
   input=round(rand(1,N*102));%信息序列
   u1=2*input-1;
   u1=sign(u1+sgma*randn(size(u1))+eps);
   u1=(u1+1)/2;
   p1(i)=(length(find(input~=u1)))/length(input);%没有经过信道编译码的误码率

end; 

for i=1:length(snr_in_DB)   
    pb(i)=main(snr_in_DB(i));%py为没有经过信道编码的误码率，pb为经过信道编码的误码率
end;

echo on;
% semilogy(SNR_in_DB,y);%误码率理想特性曲线
% hold on
% semilogy(snr_in_DB,py,'b');
% semilogy(snr_in_DB,pb,'r');
semilogy(SNR_in_DB,y,'-o',snr_in_DB,p1,'-+'');
xlabel('SNR');
ylabel('BER(db)');
% set(gca,'Ytick',[1*10^(-5)]);
legend('theory','noencoding','encoding');
grid on;
% py
% pb
toc
%  plot(SNR_in_DB,log10(y));%误码率理想特性曲线
% plot(SNR_in_DB,y);