Wp=0.4*pi;%(‘请输入通带截止频率:’)
Ws=0.6*pi;%(‘请输入阻带截止频率:’)
delta1=0.01;%(‘请输入通带容许偏芹手差:’)
delta2=0.001;%(‘请输入阻带容许偏差:’)
Ap=20*log10(2/(1-delta1)-1)%设计要求的通带最大衰减(db)
As=-20*log10(delta2/(delta1+1))%设计要求的阻带最小衰减(db)
delta_w=2*pi/1000;
Wsi=Ws/delta_w+1;Wpi=Wp/delta_w;
f=[Wp/pi,Ws/pi];m=[1,0];dev=[delta1,delta2];
[n,fo,ao,weights]=remezord(f,m,dev);
h=remez(n,fo,ao,weights);
[H,w]=freqz(h,1,1000,'whole');
H=(H(1:1:501));w=(w(1:1:501));
mag=abs(H);
db=20*log10((mag+eps)/max(mag));
Asd=-max(db(Wsi:1:501));
while Asd n=n+1; h=remez(n,fo,ao,weights); [H,w]=freqz(h,1,1000,'whole'); H=(H(1:1:501))'; w=(w(1:1:501))';mag=abs(H); db=20*log10((mag+eps)/max(mag)); Asd=-max(db(Wsi:1:501)); end M=n h=remez(M,fo,ao,weights); [H,w]=freqz(h,1,1000,'whole'); H=(H(1:1:501))';w=(w(1:1:501))';mag=abs(H); db=20*log10((mag+eps)/max(mag)); Apd=-(min(db(1:1:Wp/delta_w+1)))%实际得到的最大通带衰减 Asd=-round(max(db(Wsi:1:501)))%实陪手际得到的最小阻带衰减 subplot(2,1,1); stem([0:1:M],h); title('实际的脉冲响应','fontsize',8) axis([0,M,-0.1,0.5]); xlabel('n','fontsize',8) ylabel('h(n)','fontsize',8) set(gca,'XTickMode','manual','XTick',[0,M]) set(gca,'YTickMode','manual','YTick',[-0.1:0.1:0.5]) subplot(2,1,2); plot(w/pi,db) title('以分贝形式表示的幅度响应','芦首嫌fontsize',8); axis([0,1,-100,10]); xlabel('frequency(*pi)','fontsize',8); ylabel('db','fontsize',8); set(gca,'XTickMode','manual','XTick',[0,0.4,0.6,1]) set(gca,'YTickMode','manual','YTick',[-600]) set(gca,'YTickLableMode','manual','YTickLa-bel',{'60','0'}) grid
儿童
二十世纪