ss_pe95.m

扩频通信中对强窄带干扰进行变换域预测后系统的误码率

function[p]=ss_Pe95(snr_in_dB,Lc,A,w0)
snr=10^(snr_in_dB/10);
sgma=1;
Eb=2*sgma^2*snr;
E_chip=Eb/Lc;
N=10000;
num_of_err=0;
for i=1:N,
    temp=rand;
    if (temp<0.5),
        data=-1;
    else
        data=1;
    end;
    for j=1:Lc,
        repeated_data(j)=data;
    end;
    for j=1:Lc,
        temp=rand;
        if (temp<0.5),
            pn_seq(j)=-1;
        else
            pn_seq(j)=1;
        end;
    end;
    trans_sig=sqrt(E_chip)*repeated_data.*pn_seq;
    noise=sgma*randn(1,Lc);
    n=(i-1)*Lc+1:i*Lc;
    interference=A*sin(w0*n);
    rec_sig=trans_sig+noise+interference;
    Y=fft(rec_sig);%进行FFT变换
    for i=1:length(Y),
        if abs(Y(i))>45
            Z(i)=0;
        else
            Z(i)=Y(i);
        end;
    end;
    Z_sig=ifft(Z);
    temp=Z_sig.*pn_seq;
    decision_variable=sum(temp);
    if (decision_variable<0),
       decision =-1;
    else
        decision=1;
    end;
    if (decision~=data),
        num_of_err=num_of_err+1;
    end;
end;
p=num_of_err/N;