exa5_23.m

matlab应用实例。如：FIR、IIR数字滤波器设计等。

%--------------------------------------------------------------------------
% exa060606_remezord.m,   for example 6.6.6;
% to test remezord and to design lowpass FIR filter;
%-------------------------------------------------------------------------

rp = 3;          % Passband ripple
rs = 40;         % Stopband ripple
fs = 2000;       % Sampling frequency
f = [500 600];   % Cutoff frequencies
a = [1 0];       % Desired amplitudes
% Compute deviations
dev = [(10^(rp/20)-1)/(10^(rp/20)+1)  10^(-rs/20)]; 
[n,fo,ao,w] = remezord(f,a,dev,fs);
b = remez(n,fo,ao,w);
freqz(b,1,1024,fs);
title('幅度与相位响应曲线');