最大熵功率谱估计.m

matlab,功率谱估计

clf;
N=1024;
Nfft=256;
Fs=1000;
n=0:N-1;
t=n/Fs;
randn('state',0);
xn=sin(2*pi*50*t)+2*sin(2*pi*120*t)+randn(1,N);
[Pxx1,f]=pmem(xn,14,Nfft,Fs);
subplot(211)
plot(f,10*log10(Pxx1));
xlabel('Frequency (Hz)');ylabel('Power Spectrum (dB)');
title('Maxmum Entropy Method (MEM) Oder=14');
grid

N=1024;
Nfft=256;
Fs=1000;
n=0:N-1;
t=n/Fs;
randn('state',0);
xn=sin(2*pi*50*t)+2*sin(2*pi*120*t)+randn(1,N);
w=hanning(256);
overlap=128;
dflag='none';
[Pxx2,f]=psd(xn,Nfft,Fs,w,overlap,dflag);
subplot(212)
plot(f,10*log10(Pxx2));
xlabel('Frequency (Hz)');ylabel('Power Spectrum (dB)');
title('PSD Method');
grid