www.gusucode.com > dsp 案例源码程序 matlab代码 > dsp/FrequencyResponseOfHalfbandDecimatorExample.m
%% Impulse and Frequency Response of Half-band Decimation Filter % Create a lowpass half-band decimation filter for data sampled at 44.1 % kHz. The output data rate is 1/2 the input sampling rate, or 22.05 kHz. % Specify the filter order to be 52 with a transition width of 4.1 kHz. % Copyright 2015 The MathWorks, Inc. Fs = 44.1e3; filterspec = 'Filter order and transition width'; Order = 52; TW = 4.1e3; firhalfbanddecim =dsp.FIRHalfbandDecimator('Specification',filterspec,... 'FilterOrder',Order,... 'TransitionWidth',TW,... 'SampleRate',Fs); %% % Plot the impulse response. The zero-th order coefficient is delayed 26 % samples, which is equal to the group delay of the filter. This yields a % causal half-band filter. fvtool(firhalfbanddecim,'Analysis','impulse') %% % Plot the magnitude and phase response. fvtool(firhalfbanddecim,'Analysis','freq')