DSp实验七频率采样法及优化设计法设计FIR滤波器

实验七频率采样法及优化设计法设计FIR滤波器实验一N=40;Hk=[zeros(1,3),0.5,ones(1,5),0.5,zeros(1,1),0.5,ones(1,5),0.5,zeros(1,5),-0.5,-ones(1,5),zeros(1,2),-0.5,-ones(1,5),-0.5,zeros(1,2)];k=0:N-1;hn=real(ifft(Hk.*exp(-j*pi*(N-1)*k/N)));[Hw]=freqz(hn,1);plot(w/pi,20*log10(abs(H)));grid;axis([01-6010]);xlabel('f/Hz');ylabel('幅度');00.10.20.30.40.50.60.70.80.91-60-50-40-30-20-10010f/Hz幅度实验二N=40;M=N-1;f=[0,0.15,0.2,0.4,0.5,0.55,0.6,0.8,0.9,1];a=[0011001100];weight=[21212];h=remez(M,f,a,weight);[Hw]=freqz(h,1);plot(w/pi,20*log10(abs(H)));grid;xlabel('f/Hz');ylabel('幅度');00.10.20.30.40.50.60.70.80.91-80-70-60-50-40-30-20-10010f/Hz幅度实验三f=[500800];fs=5000;a=[01];dev=[0.10870.009];[M,fpts,mag,wt]=remezord(f,a,dev,fs);h=remez(M,fpts,mag,wt);[H,w]=freqz(h,1);plot(w*2000/pi,20*log10(abs(H)));grid;xlabel('f/Hz');ylabel('·ù¶È');0200400600800100012001400160018002000-90-80-70-60-50-40-30-20-10010f/Hz幅度