自适应滤波器毕业设计论文

N=500; M=20; n=1; a1=-0.8; h=zeros(M,n+1,3); e=zeros(M,n,3); for d=1:3 if d==1 delta=0.01; else delta=0.05*(d-1); end; for k=1:M b=0.2*randn(1,N); y(1)=1; for i=2:N y(i)=-a1*y(i-1)+b(i); end for i=n+1:N e(k,i,d)=y(i)-h(k,i,d)*y(i-1); h(k,i+1,d)=h(k,i,d)+delta*y(i-1)*e(k,i,d); end end end for d=1:3 for i=1:N em(i,d)=0; hm(i,d)=0; for j=1:M em(i,d)=em(i,d)+e(j,i,d)^2; hm(i,d)=hm(i,d)+h(j,i,d); end end end figure(1) semilogy(1:150,em(1:150,1)),hold on semilogy(1:150,em(1:150,2),'r'),hold on semilogy(1:150,em(1:150,3),'g'),hold off axis([0 150 0.01 1]),grid title('Mean square error ') xlabel('Samples') gtext('\leftarrowd=0.01'); gtext('\leftarrowd=0.05'); gtext('\leftarrowd=0.1'); figure(2),plot(1:N,hm(1:N,1)),hold on plot(1:N,hm(1:N,2),'r'),hold on plot(1:N,hm(1:N,3),'g'),hold off,grid title('Filter coeffcient evalution') xlabel('Samples'), gtext('d=0.01'), gtext('d=0.05'), gtext('d=0.1') （2）从噪声中提取信号的程序如下： N=1000; n=200; k=12; Ts=1e-1 b=0.8*randn(1,N); for i=1:N xr(1,i)=sin(k*2*pi*i/N); x(1,i)=xr(1,i)+b(i); end Cxx=10000*eye(n); g=zeros(N,n); h=zeros(N,n); e=zeros(1,N); y=zeros(1,N); tr=zeros(1,N); for i=n+1:N g(i,:)=(Cxx*x(i-n+1:i)'./(1+x(i-n+1:i)*Cxx*x(i-n+1:i)'))'; e(1,i)=xr(i)-h(i-1,:)*x(i-n+1:i)'; h(i,:)=h(i-1,:)+e(1,i)*g(i,:); Cxx=Cxx-g(i,:)'*x(i-n+1:i)*Cxx; y(1,i)=h(i,:)*x(i-n+1:i)'; tr(1,i)=trace(Cxx); end figure(1) plot(0:N-n,x(1,n:N)),grid title('x(k) input singnal in V') xlabel('Samples') figure(2) plot(0:N-n,xr(1,n:N),'r'),grid axis([0 800 -1.2 1.2]) title('xr(k) reference singnal in V') xlabel('Samples') figure(3) plot(0:N-n,e(1,n:N)),hold on plot(0:N-n,y(1,n:N),'r'),hold on grid title('e(k) error and y(k) output in V') xlabel('Samples') gtext('e(k)'),gtext('y(k)') figure(4) plot(0:N-n,h(n:N,1)),hold on plot(0:N-n,h(n:N,2),'r'),hold off grid title('a(n-1) and a(n-2) coeffcients evolution') xlabel('Samples') figure(5) num1=fliplr(h(N,:)); sys1=tf(num1,1,Ts); bode(sys1),hold off title('Synthesized filter') xlabel('Frequency in rad/s') ylabel('Phase in degree;Module in dB') figure(6) semilogy(0:N-n,tr(n:N)),grid title('Cxx matrix trace') xlabel('Samples')