基于MATLAB的IIR数字滤波器的设计

MATLABIIR,X(,411101):DSP,MATLAB,.MATLAB,,.IIRMATLAB.:IIR;(DSP);MATLAB;:TN911.72:A:1671-119X(2004)03-0008-030,,.,,;,.,01,..,.,.IIRMATLAB.1IIR,,(IIR)(FIR).IIR,,,:y(n)=Mi=0bix(n-i)-Nk=1aky(n-k):H(z)=Mi=0biz-11+Nk=1akz-kIIRH(z),H(ej),.2IIRIIR,,,;,.MATLABMATLAB,,.IIR:(1),:,::p,s,c;sp;(2).Wp1,Ws,:=2Ttan214320049JournalofHunanInstituteofEngineeringVo1.14.No.3Sept.2004X:2003-12-19:(1964-),,,:.(3)Ha(s);(Butterworth)(Chebyshev)(Cauer)(Bessel),.(4):Ha(s)H(z).(5)H(z).(.)(6).:.DF:,.,,;,,..,,.IIR,MATLAB,;,.3IIRMATLAB3.1MATLABMATLAB,,MATLAB.,,,.MATLAB,,.,MATLAB.3.2IIRMATLABIIRIIRMATLAB.IIR:p0=0.5;p1=0.4,p2=0.6;p=3dB;s=15dB;s2=0.7;T=510-6s.MATLAB:%wp0=0.53pi;wp1=0.43pi;wp2=0.63pi;Ap=3;ws2=0.73pi;As=15;T=53pi310^(-6);%%ws1=wp0-(ws2-wp0);wc1=(2/T)3tan(wp1/2);wc2=(2/T)3tan(wp2/2);wr1=(2/T)3tan(ws1/2);wr2=(2/T)3tan(ws2/2);w0=(2/T)3tan(wp0/2);B=wc2-wc1;%normwr1=(((wr1^2)-(w0^2))/(B3wr1));normwr2=(((wr2^2)-(w0^2))/(B3wr2));normwc1=(((wc1^2)-(w0^2))/(B3wc1));normwc2=(((wc2^2)-(w0^2))/(B3wc2));%if(abs(norm-wr1)-abs(normwr2))0normwr=abs(normwr2);elsenormwr=abs(normwr1);endnormwc=1;N=buttord(normwc,normwr,Ap,As,s);[bLP,aLP]=butter(N,normwc,s);[bBP,aBP]=lp2bp(bLP,aLP,w0,B);%Fs=1/T;[b,a]=bilinear(bBP,aBP,Fs);w=linspace(0,23pi,500);h=freqz(b,a,w);plot(w,203log10(abs(h)));axis([0,23pi,-120,20]);gridxlabel(frequency(rad));ylabel(gain(db));sys=tf(b,a,T)93:MATLABIIR1IIRIIR1.4:(PC)(CFORTRAN);DSP.DSP,;,,;;DSP.,,DSP,,,,,;;,DSP;FPGAASIC.FPGA,AlteraXilinxVHDL,.5,MATLAB,IIR.IIR,,.,,IIR;IIR,z,.,.,.,IIR,,.FIR,.[1].DSP[M].,2002.[2],.MATLAB[M].,2001.[3],,.MATLAB6.x[M].,2002.[4].MATLABDSP[J].,2003,(9).DesignofIIRDigitalFilterBasedonMATLABCHENAi-ping,HUXiao-dong(Dept.ofElect.andInformationEng.,HunanInstituteofEngineering,Xiangtan411101,China)Abstract:WhenDSPsystemisdesigned,algorithmsmustbesimalatdbyMATLABsothatbestalgorithmsandparameterscanbedetemined.BysignalprocessingtoolboxofMATLAB,thedigitalfiltercanbedesignedandtheanalogfiltermodelcanbebuilt.Thispaperintroducesdesignprincipleofdigitalfilter,proceduresandreal2izationwithMATLAB.Keywords:IIRdigitalfilter;digitalsignalprocessing(DSP);MATLAB;simulation012004