ftf2.m

该程序是用MATLAB编写的自适应信号处理中的FTF算法.该算法用四个 滤波器来实现对权值的更新

clear all
clc
M=100;
N=2; %滤波器阶数
del=0.001;
a1=1.558;
a2=-0.81;
v=randn(1,M);
u(1)=v(1);
for n=2:M-1
    u(2)=a1*u(1)+v(2);
    u(n+1)=a1*u(n)+a2*u(n-1)+v(n+1); 
    d(2)=0.2*u(2)+0.7*u(1);
    d(n+1)=0.2*u(n+1)+0.7*u(n);
end
%初始化
aN=zeros(1,N);bN=zeros(1,N);kN=zeros(1,N);
wN=zeros(M,N);gN=zeros(1,N);k=0;
r=ones(N+1,N);epsf=1;epsb=1;
for n=N+1:100
    x2=u(n:-1:n-1); x3=u(n-1:-1:n-2);     %输入序列赋值 
    ef(n,n-1)=u(n)-x3*aN';
    ef(n,n)=r(N,n-1)*ef(n,n-1); 
    efn1=ef(n,n-1);
    efnn=ef(n,n);
    epsf0=epsf;
    epsf=epsf+efnn*efn1;
    aN=aN+ef(n,n-1)*gN;
    r(N+1,n)=epsf0*r(N,n-1)/epsf;
    kN1=[0 gN]+efnn/epsf*[1 -aN];
   for m=1:N
       kN(m)=kN1(m);
   end
   k=kN1(end);
    eb(n,n-1)=u(n-N)-x2*bN';ebn1=eb(n,n-1);
    r(N,n)=1/(1-k*ebn1)*r(N+1,n);
    eb(n,n)=r(N,n)*ebn1;   
    ebnn=eb(n,n);
    epsb=epsb+ebnn*ebn1;
    gN=(kN+k*bN)*r(N,n)/r(N+1,n);
    bN=bN+gN*ebn1;
    e(n,n-1)=d(n)-x2*wN(n-1,:)';
    en1=e(n,n-1);
    wN(n,:)=wN(n-1,:)+gN*en1;
end 
plot(wN)