jietiaoheyantu.m

文件中包含了详细的8PSK调制解调的原理和代码

clear;
close all;
Fd=1;                           %消息序列的采样速率
Fs=4*Fd;                          %已调信号的采样速率
M=8;
SNR_db=0:12                 %仿真信噪比范围
SNR1_db=0:0.1:12                   %理论计算信噪比范围
%误码情况仿真
for n=1:length(SNR_db)
    Eb_N0=10^(SNR_db(n)/10);
    sgma=sqrt(1/(8*Eb_N0));           %nc,ns的均方差
    x=randint(50,1,8);              %产生二进制随机序列
    %x1=bin2dec('x')
   %x2=dec2base(x1,8)
    subplot(2,2,4)
    plot(x),title('二进制序列')
    y=dmodce(x,Fd,Fs,'psk',M);           %psk调制
    yzaosheng=y+sqrt(Fs/Fd)*sgma*(randn(length(y),1)+j*randn(length(y),1)); %加噪
    subplot(2,2,1)
   plot(y,'*'),title('8psk调制图形')
    z=ddemodce(yzaosheng,Fd,Fs,'psk',M); %解调
    subplot(2,2,2)
    plot(z),title('解调图形')
    [numbers,pm(n)]=symerr(x,z); %计算误符号率
end;
st=z;
ts=1;
n=20;
n_sample=8;
eye_num=10;
dt=ts/n_sample;
t=0:dt:(n*n_sample-1)*dt;
ht1=sinc((t-5)/ts);
rt1=conv(st,ht1);
ht2=sinc((t-5)/ts);
rt2=conv(st,ht2);
ss=zeros(1,eye_num*n_sample);
ttt=0:dt:eye_num*n_sample*dt-dt;
for k=3:50
    ss=rt2(k*n_sample+1:(k+eye_num)*n_sample);
    drawnow;
    subplot(223)
    plot(ttt,ss);
    axis([0,10,-1,1])
    hold on;
end
xlabel('t''ts');
ylabel('基带信号眼图');