www.gusucode.com > dsp 案例源码程序 matlab代码 > dsp/DesignOfLowpassDecimatorExample.m
%% Design of Lowpass Decimator % This example requires the DSP System Toolbox product. % % Design a 100-tap FIR lowpass decimator filter that reduces the sample rate % of a signal from 60 kHz to 20 kHz. The passband of the filter extends up to % 6 kHz. Specify a passband ripple of 0.01 dB and a stopband attenuation of 100 % dB. % Copyright 2015 The MathWorks, Inc. Fs = 60e3; N = 99; Fpass = 6e3; Apass = 0.01; Astop = 100; M = Fs/20e3; filtSpecs = fdesign.decimator(M,'lowpass','N,Fp,Ap,Ast',N,Fpass,Apass,Astop,Fs); %% % Design the filter and display information about it. decimFIR = design(filtSpecs,'equiripple','SystemObject',true); info(decimFIR) %% % Visualize the magnitude response of the filter. fvtool(decimFIR,'Fs',Fs) %% %