window2=blackman(100); %blackman窗 Nfft=N*T*Rb;
noverlap=0; %数据无重叠
range='onesided'; %频率间隔为[0 Fs/2]，只计算一半的频率 [Pxx,f]=pwelch(mod,window,noverlap,Nfft,fs,range); [Pxx1,f]=pwelch(mod,window1,noverlap,Nfft,fs,range); [Pxx2,f]=pwelch(mod,window2,noverlap,Nfft,fs,range);
figure(3) subplot(311)
plot(f,Pxx);axis([0 5000 0 0.001]); title('rectangular window PSD');
subplot(312)
plot(f,Pxx1);axis([0 5000 0 0.0007]); title('Hamming PSD');
subplot(313)
plot(f,Pxx2);axis([0 5000 0 0.0007]); title('Blackman PSD');
21