psk_30.m

给出 了进行相位调制的仿真程序

%+,-15度调相基本平台
clc
clear all
N=10000;%仿真数据量
data=randint(1,N);%随机数生成
data_I=[];
data_Q=[];
rec_data_I=[];
rec_data_Q=[];
rec_data=[];
data_err_rate=[];
%相位映射
for i=1:N
    if data(i)==0
        data_I(i)=cos(pi/12);
        data_Q(i)=sin(pi/12);
    else
        data_I(i)=cos(pi/12);
        data_Q(i)=-sin(pi/12);
    end
end
data_module=data_I+sqrt(-1)*data_Q;
t1=(1:length(data_module))/1e6;
data_module1=data_module.*exp(j*2*pi*(1.37*t1+0));
% scatterplot(data_module);grid;
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% a=fft(data_module);
% b=fft(data_module1);
% c=ifft(a.*conj(b));
% [cmax,nmax]=max(abs(c));
% theta=angle(c(nmax));
% data_module2=data_module1.*exp(j*theta);
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
snr_start=1;
snr_end=30;
snr_in_dB=1:2:30;
%Monte karlo 仿真
for i=1:length(snr_in_dB)
    snr=sqrt(1/2*10^(-1*(snr_in_dB(i)/10)));
    n_I=snr*randn(1,N);
    n_Q=snr*randn(1,N);
    %通过高斯信道的情况
%     sig_I=data_I+n_I;
%     sig_Q=data_Q+n_Q;
    sig_I=real(data_module1)+n_I;
    sig_Q=imag(data_module1)+n_Q;
    for j=1:N
        rec=[sig_I(j) sig_Q(j)];
        %correlation demodulation
        rec1=dot(rec,[cos(pi/12) sin(pi/12)]);
        rec2=dot(rec,[cos(pi/12) -sin(pi/12)]);
        %deciding
        if rec1>rec2
           rec_data_I(j)=cos(pi/12);
           rec_data_Q(j)=sin(pi/12);
           rec_data(j)=0;
        else
           rec_data_I(j)=cos(pi/12);
           rec_data_Q(j)=-sin(pi/12);
           rec_data(j)=1;
        end
    end
    data_err_rate(i)=sum(data~=rec_data)/N;
end
%drawing
semilogy(snr_in_dB,data_err_rate);grid on;
% grid on