qpsk_fading.m

关于通信基本原理的仿真

%%%%% QPSK 衰落信道仿真实例 %%%%%%%%%%%%
clc;
clear all;
EbN0dB=0:5:35;%设定信噪比
errLimit=50;
N=100;
M=10;
Mc=2;
Es=2;
for ii=1:length(EbN0dB)
    errCount=0;
    totalN=0;
    N0=Es/(Mc*(10^(EbN0dB(ii)/10)));
    while errCount<errLimit
        source=randint(M*Mc,N);
        trans=qpsk_mod(source);
        transtochan=reshape(trans,1,M*N);
        h=sqrt(1/2)*(randn(1,M*N)+j*randn(1,M*N));
        receiver=transtochan.*h+sqrt(N0/2)*(randn(1,length(transtochan))+j*randn(1,length(transtochan)));
        data1=receiver.*conj(h)./(abs(h).^2);
        chantodemod=reshape(data1,M,N);
        demodata=qpsk_demod(chantodemod);
        temp=sum(sum(abs(source-demodata)));
        errCount=errCount+temp;
        totalN=totalN+M*N*Mc;
    end
    ber(ii)=errCount/totalN;
end
ber
semilogy(EbN0dB,ber,'-o');
hold on;
grid on;
berth=berfading(EbN0dB,'psk',4,1);
semilogy(EbN0dB,berth,'-*');