[snr2,snr22,snr23,snr24,snr25];РZ=fft(sn);РZ=abs(Z(1:length(Z)/2+1));РfrqZ=[0:length(Z)-1]*Fs/length(Z)/2; %无噪声解调信号频谱РZ1=fft(sn1);РZ1=abs(Z1(1:length(Z1)/2+1));РfrqZ1=[0:length(Z1)-1]*Fs/length(Z1)/2; %加噪声解调信号频谱Рfigure(1);Рsubplot(1,2,1)Рplot(t,m); title('调制信号')Рsubplot(1,2,2)Рplot(frqX,X);title('调制信号频谱')Рaxis([0 3000 0 max(X)]);РfigureРsubplot(2,2,1)Рplot(t,sm);title('已调信号')Рsubplot(2,2,2)Рplot(frqY,Y); title('无噪声已调信号频谱')Рsubplot(2,2,3)Рplot(frqY1,Y1);title('加噪声已调信号频谱')РfigureРsubplot(1,2,1)Рplot(t,sn);title('无噪声解调信号波形')Рsubplot(1,2,2)Рplot(frqZ,Z); title('无噪声解调信号频谱')Рaxis([0 3000 0 max(Z)])РfigureРsubplot(1,2,1)Рplot(t,sn1);title('加噪声解调信号波形')Рsubplot(1,2,2)Рplot(frqZ1,Z1); title('加噪声解调信号频谱')Рaxis([0 3000 0 max(Z)]);РfigureРplot(in,out)Рxlable('输入信噪比')Рylable('输出信噪比')Р 图3-1(a) 调制信号时域图及频谱图
全文预览