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+====== 完全重建QMF滤波器组的设计 ======
+推导  https://www.cnblogs.com/welen/p/6143810.html
+https://blog.csdn.net/wzz4420381/article/details/48676921?utm_source=blogxgwz4
+https://blog.csdn.net/jobfind/article/details/89308673
+<code>
+N=41;
+w=0.43;
+[h0,h1,g0,g1]=firpr2chfb(N,w);
+[H1z,w]=freqz(h0,1,512);
+H1_abs=abs(H1z);H1_db=20*log10(H1_abs);
+[H2z,w]=freqz(h1,1,512);
+H2_abs=abs(H2z);H2_db=20*log10(H2_abs);
+%%%%%%%%%%滤波器h0和h1的幅度响应%%%%%%%%%%
+figure(1);
+plot(w/pi,H1_db,'-',w/pi,H2_db,'--');
+axis([0,1,-100,10]);
+grid
+xlabel('\omega/\pi');ylabel('幅度,dB');
+sum1=H1_abs.*H1_abs+H2_abs.*H2_abs;
+d=10*log10(sum1);
+%%%%%%%%%%%%幅度响应关系误差%%%%%%%%%%%%%
+figure(2)
+plot(w/pi,d);grid;
+xlabel('\omega/\pi');ylabel('误差,dB');
+axis([0,1,-0.04,0.04]);
+%%%%%%%%%%%%%x1(n)%%%%%%%%%%%%%%%%%%%%%
+x=zeros(1,500);
+x(2)=1;x(3)=1;
+x(6)=2;x(7)=2;x(8)=2;
+x(17)=1.5;x(18)=1.5;x(19)=1.5;
+x(24)=1;x(25)=1;
+x(33)=3;x(34)=3;x(35)=3;
+%%%%%%%%%%%%%%x2(n)%%%%%%%%%%%%%%%%%%%%
+x=zeros(1,500);
+x(1)=1;x(2)=1;x(3)=1;
+x(9)=2;x(10)=2;x(11)=2;
+x(16)=3;x(17)=3;x(18)=3;
+x(24)=4;x(25)=4;x(26)=4;
+x(33)=3;x(34)=3;x(35)=3;
+x(41)=2;x(42)=2;x(43)=2;
+x(49)=1;x(50)=1;x(51)=1;
+%%%%%%%%%%%%%%x3(n)%%%%%%%%%%%%%%%%%%%%
+n=1:500;
+T=0.2;
+x=sin(n*T);
+hlp=mfilt.firdecim(2,h0);
+hhp=mfilt.firdecim(2,h1);
+glp=mfilt.firinterp(2,g0);
+ghp=mfilt.firinterp(2,g1);
+x0=filter(hlp,x);
+x0=filter(glp,x0);
+x1=filter(hhp,x);
+x1=filter(ghp,x1);
+xidle=x0+x1;
+xshift=[zeros(1,N) x(1:end-N)];
+e=xidle-xshift;
+mes=sum(abs(e).^2)/length(e)
+fvtool(h0)
+%%%%%%%%%%%%输入信号%%%%%%%%%%%%%%%%%%
+figure(4);
+plot(x);
+%%%%%%%%%%理想输出信号与重建输出信号%%%%%%%
+figure(5);
+axis([0,500,-1,1]);
+plot(xshift,'r');hold on;
+plot(xidle,'-');
+axis([0,600,-1.1,1.1]);
+%%%%%%%理想输出信号与重建输出信号的偏差%%%%%%
+figure(6);
+plot(xshift-xidle);
+</code>

GuangZhou Xinsi Technology Co. Ltd.

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