1.滤波器和输出误差的功率谱.m

自适应线性预测编码问题

clear;
clc;


A=[1:300;linspace(0,0,300)];
A=A';
A1=[1:300;linspace(0,0,300)];
A1=A1';
A2=[1:300;linspace(0,0,300)];
A2=A2';

B=[];
B1=[];
B2=[];
    V=sqrt(0.27)*randn(500,1);          % 产生白噪声序列V(n)
    X=[0+V(1);0+V(2)];
    for n=3:500                         % 产生准信号序列
        x=-0.1*X(n-1)+0.8*X(n-2)+V(n);
        X=[X;x];
    end
    X=X(201:500);                       % 截取信号序列X(n)

    H=[-1; -2];                         % 初始滤波器系数H(0)
    T=H';
    e=0;
    e2=0;
    for n=2:299
        e=X(n+1)-H'*[X(n);X(n-1)];      % 计算每步误差e(n+1)
        A(n+1,:)=A(n+1,:)+e;
        B=[B,e];
        H=H+0.05*e*[X(n);X(n-1)];       % 计算每步滤波器系数H(n+1)
        A1(n+1,:)=A1(n+1,:)-0.1-H(1);
        B1=[B1,-0.1-H(1)];
        A2(n+1,:)=A2(n+1,:)+0.8-H(2);
        B2=[B2,0.8-H(2)];
    end
    
h = spectrum.periodogram; 

A=A';
figure(1)
plot(A(1,:),A(2,:));
figure(11);
psd(h,B);

A1=A1';
figure(2)
plot(A1(1,:),A1(2,:));
figure(21);
psd(h,B1);

A2=A2';
figure(3)
plot(A2(1,:),A2(2,:));
figure(31);
psd(h,B2);