ly2.m

MATLAB的程序最大熵谱法,Brug法和Levinson法MATLAB procedures maximum entropy spectrum, Brug law and the law Levin

clear;
clc;
N=1024;
Nfft=128;
n=[0:N-1];
randn('state',0);
wn=randn(1,N);
xn=sqrt(20)*sin(2*pi*0.2*n)+sqrt(20)*sin(2*pi*0.3*n)+wn;
[Pxx1,f]=pburg(xn,15,Nfft,1);                                 %用Brug法进行功率谱估计，阶数为15，点数为1024
Pxx1=10*log10(Pxx1);
hold on;
subplot(2,2,1);plot(f,Pxx1,'g');
xlabel('Frequency');
ylabel('Power Spectrum (dB)');
title('Burg法  order=15,N=1024');
grid on;

[Pxx2,f]=pburg(xn,20,Nfft,1);                                 %用Brug法进行功率谱估计，阶数为20，点数为1024
Pxx2=10*log10(Pxx2);
hold on
subplot(2,2,2);plot(f,Pxx2,'g');
xlabel('Frequency');
ylabel('Power Spectrum (dB)');
title('Burg法  order=20,N=1024');
grid on;

N=512;
Nfft=128;
n=[0:N-1];
randn('state',0);
wn=randn(1,N);
xn=sqrt(20)*sin(2*pi*0.2*n)+sqrt(20)*sin(2*pi*0.3*n)+wn;
[Pxx3,f]=pburg(xn,15,Nfft,1);                                 %用Brug法进行功率谱估计，阶数为15，点数为512
Pxx3=10*log10(Pxx3);
hold on
subplot(2,2,3);plot(f,Pxx3,'g');
xlabel('Frequency');
ylabel('Power Spectrum (dB)');
title('Burg法  order=15,N=512');
grid on;

[Pxx4,f]=pburg(xn,10,Nfft,1);                                %用Brug法进行功率谱估计，阶数为10，点数为256
Pxx4=10*log10(Pxx4);
hold on
subplot(2,2,4);plot(f,Pxx4,'g');
xlabel('Frequency');
ylabel('Power Spectrum (dB)');
title('Burg法  order=10,N=256');
grid on;