數(shù)字信號(hào)處理實(shí)驗(yàn)三

5IIR一、實(shí)驗(yàn)?zāi)慷?shí)驗(yàn)計(jì)算機(jī)、軟件環(huán)境三、實(shí)驗(yàn)基礎(chǔ)理1原應(yīng)h??(??)，h(n)等于h??(??)的取樣值。2方a 思路H(s變換h(t采樣h(nTh(n換a 將H??(??)??(??)=

對(duì)H??(??)

??=1???(??)= ??????????對(duì)h??(??)h(n)=

????????????????(????)=

H(z)=

3、設(shè)計(jì)步

??=1確定數(shù)字濾波器性能指標(biāo)pstRpAs

根據(jù)指標(biāo)pstRp和AsHaHa(sNNHa(s)k

A spkkp轉(zhuǎn)換成數(shù)字極點(diǎn)epkTkNH(z) N可見H??(??)H(z)

k11epkT1

在中有兩種方法可以實(shí)現(xiàn)上述變換1residueresiduez函數(shù)實(shí)現(xiàn)脈沖響應(yīng)不變法，這兩個(gè)函數(shù)的使用方法如[b,a]=[b,a]=方法2：提供了impinvar函數(shù)采用脈沖響應(yīng)不變法實(shí)現(xiàn)模擬濾波器到數(shù)字濾波器babzaz，fs（1[bz,az]=impinvar(b,a)1四、實(shí)驗(yàn)內(nèi)實(shí)驗(yàn)過程與實(shí)驗(yàn)結(jié)果調(diào)用impinvar函數(shù)采用脈沖響應(yīng)不變法實(shí)現(xiàn)模擬濾波器到數(shù)字濾波器的變換，并利用freqz函數(shù)來計(jì)算數(shù)字濾波器的頻率響應(yīng)，同時(shí)利用grpdelay函數(shù)計(jì)算群延時(shí)響應(yīng)：a=[12*wc2*wc^2wc^3];gridon;xlabel('\omega(\pi)');ylabel('|H(e^j^\omega)|');gridon;xlabel('\omega(\pi)');ylabel('|H(e^j^\omega)|');gridon;xlabel('\omega(\pi)'),ylabel('Groupdelay');bz az G4.547e-16+0.5813z^-1+0.2114z^-1-0.3984z^-1+0.2475z^-2-0.04321z^-Sampletime:0.1secondsDiscrete-timetransferfunction.1

1PhasePhaseof0

Group1Group0 要求分別采用、切比I型、切比II型和橢圓模擬原型濾波器及脈沖響應(yīng)不IIR數(shù)字濾波器的優(yōu)缺點(diǎn)及適用范圍。實(shí)驗(yàn)過程與實(shí)驗(yàn)結(jié)果①grpdelay函數(shù)計(jì)算群延時(shí)響應(yīng)：gridon;xlabel('\omega(\pi)');ylabel('|H(e^j^\omega)|');gridon;xlabel('\omega(\pi)');ylabel('|H(e^j^\omega)|');gridon;xlabel('\omega(\pi)'),ylabel('PhaseofH(e^j^\omega)');gridon;xlabel('\omega(\pi)'),ylabel('Groupdelay');bz az G0.000631z^-1+0.0101z^-2+0.01614z^-3+0.004101z^-4+ z^-1-3.364z^-1+5.068z^-2-4.276z^-3+2.107z^-4-0.5706z^-5+0.06607z^-Sampletime:0.1secondsDiscrete-timetransferfunction.Phase0Phase0②切比Ⅰ型濾波器的頻率響應(yīng)，同時(shí)利用grpdelay函數(shù)計(jì)算群延時(shí)響應(yīng)：gridon;xlabel('\omega(\pi)');ylabel('|H(e^j^\omega)|');gridon;xlabel('\omega(\pi)');ylabel('|H(e^j^\omega)|');gridon;xlabel('\omega(\pi)'),ylabel('PhaseofH(e^j^\omega)');gridon;xlabel('\omega(\pi)'),ylabel('Groupdelay');bz az G0.005373z^-1+0.0181z^-2+0.003985z^-1-3.059z^-1+3.832z^-2-2.292z^-3+0.5495z^-Sampletime:0.1secondsDiscrete-timetransferfunction.0

1PhasePhaseof0

GroupGroup50 ③切比Ⅱ型濾波器的頻率響應(yīng)，同時(shí)利用grpdelay函數(shù)計(jì)算群延時(shí)響應(yīng)：gridon;xlabel('\omega(\pi)');ylabel('|H(e^j^\omega)|');gridon;xlabel('\omega(\pi)');ylabel('|H(e^j^\omega)|');gridon;xlabel('\omega(\pi)'),ylabel('Phaseofgridon;xlabel('\omega(\pi)'),ylabel('Groupdelay');bz az G-0.4214+0.9724z^-1-0.8119z^-2+0.4205z^-3+1.663e-06z^-1-1.666z^-1+1.429z^-2-0.5193z^-3+0.09352z^-Sampletime:0.1secondsDiscrete-timetransferfunction.0

1PhasePhaseof0

Group0Group ④波器的頻率響應(yīng)，同時(shí)利用grpdelay函數(shù)計(jì)算群延時(shí)響應(yīng)：gridon;xlabel('\omega(\pi)');ylabel('|H(e^j^\omega)|');gridon;xlabel('\omega(\pi)');ylabel('|H(e^j^\omega)|');gridon;xlabel('\omega(\pi)'),ylabel('PhaseofH(e^j^\omega)');gridon;xlabel('\omega(\pi)'),ylabel('Groupdelay');bz az G0.1855+0.04956z^-1+0.04956z^-2+0.1855z^-1-1.411z^-1+1.236z^-2-0.3549z^-Sampletime:0.1secondsDiscrete-timetransferfunction.10

1PhasePhaseof0

GroupGroup50 freqz函數(shù)來計(jì)算數(shù)字濾波器的頻率響應(yīng)，同時(shí)利用grpdelay函數(shù)a=[12*wc2*wc^2wc^3];gridon;xlabel('\omega(\pi)');ylabel('|H(e^j^\omega)|');gridon;xlabel('\omega(\pi)');ylabel('|H(e^j^\omega)|');gridon;xlabel('\omega(\pi)'),ylabel('PhaseofH(e^j^\omega)');gridon;xlabel('\omega(\pi)'),ylabel('Groupdelay');bz az G0.1057z^-1+0.06633z^-1-1.649z^-1+1.066z^-2-0.245z^-Sampletime:0.1secondsDiscrete-timetransferfunction.10

1PhasePhaseo