exa5_21.m

matlab应用实例。如：FIR、IIR数字滤波器设计等。

%--------------------------------------------------------------------------
% exa060604_firls.m,   for example 6.6.4;
% to test firls and to design bandpass FIR filter;
%-------------------------------------------------------------------------

F = [0 0.3  0.4 0.6  0.7 0.9]; 
A = [0  1   0  0  0.5 0.5];
b = firls(24,F,A,'hilbert');
[H,f] = freqz(b,1,512,2);
plot(f,abs(H),'k.') 
hold on
for i=1:2:6, 
   plot([F(i) F(i+1)],[A(i) A(i+1)],'k-')
   hold on
end
grid on
hold off
legend( '实际滤波器','理想滤波器')