dspn第十四次课(7章).ppt

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1、Chapter7DigitalFilterRealizations7.1DirectForm*也称directformΙrealizations(直接I型)*P.269：式(7.1.1)和(7.1.2)，Fig.7.1.1theb-multiplierterms:1)arefeedingforward(前馈)2)correspondtothenumeratorpolynomialofH(z)3)correspondtothex-dependentnon-recursivetermsof(7.1.5)thea-multiplierter

2、ms:1)arefeedingback(反馈)2)correspondtothedenominatorpolynomialofH(z)3)correspondtothey-dependentrecursivetermsof(7.1.5)Themainfeatureofthisrealizationisasingleadderthataccumulatesallthetermsintheright-handsideofEq.(7.1.5)andwhoseoutputisy(n).*sample-processingalgorithm:P

3、.270式(7.1.3)注意：的符号Thea-multiplierintheblockdiagramandinthedifferenceequationarenegativeofthedenominatorpolynomialcoefficients更一般的情况：*P.271：式(7.1.4)和(7.1.5)，Fig.7.1.2*sample-processingalgorithm:P.272式(7.1.8)Example7.1.1:7.2CanonicalForm（正准形式）也称directformIIrealizations(直接

4、II型)*以二阶系统为例：交换两串联系统的顺序，并不改变系统的输入、输出关系。Fig.7.2.2共用延迟器得到Fig.7.2.3sampleprocessingalgorithm:式(7.2.2)*推广到MthorderIIRfilter:Fig.7.2.4,式(7.2.5)7.3CascadeForm（串联形式）*second-ordersection(SOS):1)transferfunction:式(7.1.1)2)canonicalrealization:Fig.7.2.33)I/Odifferenceequations:式(

5、7.2.2)(Bysecond-orderwereallymean“uptosecondorder”)(EachSOSmayberealizedinitscanonical,direct,ortransposedrealizations.However,theconventionistorealizeallofthemintheircanonicalform)*cascaderealizationform:thetransferfunctionistheproductofsuchsecond-ordersection(SOS)*blo

6、ckdiagramrealizationofcascadeform:Fig.7.3.1*sampleprocessingalgorithmofcascadeform:式(7.3.2),式(7.3.3)Example7.3.1:7.4CascadetoCanonicalthedirectorcanonicalrealizationtothecascaderealization步骤1)Topassfromthedirectorcanonicalrealizationtothecascaderealization,requiresfacto

7、ringthenumeratoranddenominatorpolynomialsintotheirsecond-orderfactorsThiscanbedonebyfindingtherootsofthesepolynomialsandthenpairingthemincomplexconjugatepairs.2)Oncethedenominatorandnumeratorpolynomialshavebeenfactoredintotheirquadraticfactors,eachquadraticfactorfromthe

8、numeratormaybepairedwithaquadraticfactorfromthedenominatortoformasecond-ordersection.(Thispairingofnumeratoran