www.gusucode.com > dsp 案例源码程序 matlab代码 > dsp/StopbandConstraintsExample.m
%% Stopband Constraints % You can specify the shape of the stopband and the rate at which the % stopband decays. % % Create two FIR equiripple filters with different linear stopband slopes. % Specify the passband frequency to be 0.3π rad/sample and the stopband % frequency to be 0.35π rad/sample. Specify 1 dB of allowable passband % ripple and a stopband attenuation of 60 dB. Design one filter with a 20 % dB/(rad/sample) stopband slope and another filter with a slope of 40 % dB/(rad/sample). D = fdesign.highpass('Fst,Fp,Ast,Ap',0.3,0.35,60,1); Hd1 = design(D,'equiripple','StopBandShape','linear','StopBandDecay',20); Hd2 = design(D,'equiripple','StopBandShape','linear','StopBandDecay',40); %% % Visualize the magnitude responses of the filters. hfvt = fvtool([Hd1 Hd2]); legend(hfvt,'20 dB/rad/sample','40 dB/rad/sample')