gusucode.com > 噪声波形和功率绘图项目matlab源码程序 > li_2.m

    Fs = 1000;                        %取样频率
nfft=1024;                         %1024点DFT
p = 0:round(nfft/2-1);
k =p*Fs/nfft;
t = 0:1/Fs:1;

A = rand(1,1001);
[cor1 lag1] = xcorr(A,'unbiased');   % lag是信号的延时或者超前
figure(1);
subplot(211),plot(lag1/Fs,cor1),title('均匀白噪声自相关函数');
fc1 = fft(cor1,nfft);
cm = abs(fc1);
subplot(212),plot(k,10*log10(cm(p+1))),title('均匀白噪声功率谱密度');

B = randn(1,1001);
[cor2 lag2] = xcorr(B,'unbiased');
figure(2);
subplot(211),plot(lag2/Fs,cor2),title('高斯白噪声自相关函数');
fc2 = fft(cor2,nfft);
cm2 = abs(fc2);
subplot(212),plot(k,10*log10(cm2(p+1))),title('高斯白噪声功率谱密度');