dspex2.m

滤波器阶数固定时,代价函数和信噪比之间的关系 信噪比固定时,代价函数和滤波器长度之间的关系

% DSP Experiment 3.2.1 Varying Step-Size Parameter
a1=-1.5955
a2=0.95
r1=1.818
r2=0.182
x=10
Jmin=0.0322
u=[0.3,1.0]
v1=zeros(200,2)
v2=zeros(200,2)
w1=zeros(200,2)
w2=zeros(200,2)
J=zeros(200,2)
v1(1,:)=[-0.7072*(a1+a2),-0.7072*(a1+a2)]
v2(1,:)=[-0.7072*(a1-a2),-0.7072*(a1-a2)]
w1(1,:)=-0
w2(1,:)=-0
J(1,:)=r1*v1(1,:).^2+r2*v2(1,:).^2+Jmin
for k=2:200
        v1(k,:)=((1-u*r1).^k).*(v1(1,:))
        v2(k,:)=((1-u*r2).^k).*(v2(1,:))
        w1(k,:)=-a1-0.7072*(v1(k,:)+v2(k,:))
        w2(k,:)=-a2-0.7072*(v1(k,:)-v2(k,:))
        J(k,:)=r1.*v1(k,:).^2+r2.*v2(k,:).^2+Jmin
end
for k=1:2
    figure(1)
    subplot(2,1,k)
    plot(v1(:,k),v2(:,k),':b.')
   % axis([-6,6,-6,6])
    axis equal
    grid on
    hold on
    figure(2)
    subplot(2,1,k)
    plot(w1(:,k),w2(:,k),':b.')
   % axis([-6,6,-6,6])
    axis equal
    grid on
    hold on  
end
theta=0:0.01:2*pi
for m=1:5
    for k=1:2
        figure(1)
        subplot(2,1,k)
        x1=((J(m,k)-Jmin)/r1)^0.5*cos(theta)
        y1=((J(m,k)-Jmin)/r2)^0.5*sin(theta)
        plot(x1,y1,'-r')
        figure(2)
        subplot(2,1,k)
        x2=-a1-0.7072*(x1+y1)
        y2=-a2-0.7072*(x1-y1)
        plot(x2,y2,'-r')
    end    
end