中财网kiss设计原则:fir1的用法
来源：百度文库 编辑：中财网 时间：2024/04/27 09:06:01
fir1的用法
调用MATLAB窗函数fir1设计实现带通滤波器。b=fir1(n,Wn)，n表示滤波器的阶数。 %generate a compound signal s=s1+s2+s3 t=-1:.01:1; s1=sin(2*pi*5*t); s2=sinc(2*pi*25*t); s3=cos(2*pi*40*t); s=s1+s2+s3; %The compound signal 's' consists of three signal 's1','s2',s3'. subplot(311); plot(t,s); grid; axis([-1 1 -2 2]); xlabel('time/second'); ylabel('time wave'); %generate a 100_order FIR bandpass filter,band width is 20Hz-30Hz. b=fir1(100,[0.20 0.30]); %Use 'fir1' function for the bandpass filter designing. [H,F]=freqz(b,1,512); %Compute the frequency response of discrete-time bandpass filters. subplot(312); plot(F*100/pi,20*log10(abs(H))); grid; axis([0 50 -100 0]); xlabel('freqency/Hz'); ylabel('magnitude'); SF=filter(b,1,s); %Filter the desired signal 's2' from 's' with the finite impulse response (FIR) bandpass filter. subplot(313); plot(t,SF); grid; xlabel('time/Second'); ylabel('time wave');
调用MATLAB窗函数fir1设计实现带通滤波器。b=fir1(n,Wn)，n表示滤波器的阶数。 %generate a compound signal s=s1+s2+s3 t=-1:.01:1; s1=sin(2*pi*5*t); s2=sinc(2*pi*25*t); s3=cos(2*pi*40*t); s=s1+s2+s3; %The compound signal 's' consists of three signal 's1','s2',s3'. subplot(311); plot(t,s); grid; axis([-1 1 -2 2]); xlabel('time/second'); ylabel('time wave'); %generate a 100_order FIR bandpass filter,band width is 20Hz-30Hz. b=fir1(100,[0.20 0.30]); %Use 'fir1' function for the bandpass filter designing. [H,F]=freqz(b,1,512); %Compute the frequency response of discrete-time bandpass filters. subplot(312); plot(F*100/pi,20*log10(abs(H))); grid; axis([0 50 -100 0]); xlabel('freqency/Hz'); ylabel('magnitude'); SF=filter(b,1,s); %Filter the desired signal 's2' from 's' with the finite impulse response (FIR) bandpass filter. subplot(313); plot(t,SF); grid; xlabel('time/Second'); ylabel('time wave');