外文翻譯-數(shù)字濾波器的仿真與實(shí)現(xiàn)

鄭州輕工業(yè)學(xué)院畢業(yè)設(shè)計(jì)(論文)外文資料翻譯院系電子信息工程專(zhuān)業(yè)班級(jí)電子信息工程學(xué)生姓名靖世敏學(xué)號(hào)540901030111外文出處附件：1.外文資料翻譯譯文〔約3000漢字〕；2.外文資料原文(與課題相關(guān)的1萬(wàn)印刷符號(hào)左右)。指導(dǎo)教師評(píng)語(yǔ)：指導(dǎo)教師簽名：年月日英文原文ThesimulationandtherealizationofthedigitalfilterWiththeinformationageandtheadventofthedigitalworld,digitalsignalprocessinghasbecomeoneoftoday'smostimportantdisciplinesanddoortechnology.Digitalsignalprocessingincommunications,voice,images,automaticcontrol,radar,military,aerospace,medicalandhouseholdappliances,andmanyotherfieldswidelyapplied.Inthedigitalsignalprocessingapplications,thedigitalfilterisimportantandhasbeenwidelyapplied.1、figuresUniton:AnaloganddigitalfiltersInsignalprocessing,thefunctionofafilteristoremoveunwantedpartsofthesignal,suchasrandomnoise,ortoextractusefulpartsofthesignal,suchasthecomponentslyingwithinacertainfrequencyrange.Thefollowingblockdiagramillustratesthebasicidea.Therearetwomainkindsoffilter,analoganddigital.Theyarequitedifferentintheirphysicalmakeupandinhowtheywork.Ananalogfilterusesanalogelectroniccircuitsmadeupfromcomponentssuchasresistors,capacitorsandopampstoproducetherequiredfilteringeffect.Suchfiltercircuitsarewidelyusedinsuchapplicationsasnoisereduction,videosignalenhancement,graphicequilibriuminhi-fisystems,andmanyotherareas.Therearewell-establishedstandardtechniquesfordesigningananalogfiltercircuitforagivenrequirement.Atallstages,thesignalbeingfilteredisanelectricalvoltageorcurrentwhichisthedirectanalogueofthephysicalquantity(e.g.asoundorvideosignalortransduceroutput)involved.Adigitalfilterusesadigitalprocessortoperformnumericalcalculationsonsampledvaluesofthesignal.Theprocessormaybeageneral-purposecomputersuchasaPC,oraspecializedDSP(DigitalSignalProcessor)chip.TheanaloginputsignalmustfirstbesampledanddigitizedusinganADC(analogtodigitalconverter).Theresultingbinarynumbers,representingsuccessivesampledvaluesoftheinputsignal,aretransferredtotheprocessor,whichcarriesoutnumericalcalculationsonthem.Thesecalculationstypicallyinvolvemultiplyingtheinputvaluesbyconstantsandaddingtheproductstogether.Ifnecessary,theresultsofthesecalculations,whichnowrepresentsampledvaluesofthefilteredsignal,areoutputthroughaDAC(digitaltoanalogconverter)toconvertthesignalbacktoanalogform.Notethatinadigitalfilter,thesignalisrepresentedbyasequenceofnumbers,ratherthanavoltageorcurrent.Thefollowingdiagramshowsthebasicsetupofsuchasystem.

Unitreferstotheinputsignalsusedtofilterhardwareorsoftware.Ifthefilterinput,outputsignalsareseparated,theyareboundtorespondtotheimpactoftheUnitisseparated,suchasdigitalfiltersfilterdefinition.Digitalfilterfunction,whichwastoimportsequencesXtransformationintoexportoperationsthroughaseriesY.Accordingtofiguresfilterfunction24-hourliveresponsecharacteristics,digitalfilterscanbedividedintotwo,namely,unlimitedlonglivelonglivethecorrespondingIIRfilterandthelimitedresponsetoFIRfilters.IIRfiltershavetheadvantageofthedigitalfilterdesigncanusesimulationresults,andsimulationfilterdesignofalargenumberoftablesmayfacilitatesimple.Itistheshortcomingsofthenonlinearphase;Linearphaseifrequired,willusetheentirenetworkphase-correction.Imageprocessingandtransmissionofdatacollectionisrequiredwithlinearphasefiltersidentity.AndFIRlinearphasedigitalfiltertoachieve,butanarbitrarymargincharacteristics.Impactfromthedigitalfilterresponseoftheunitscanbedividedintotwobroadcategories:theimpactofthelimitedresponse(FIR)filters,andunlimitednumberofshocksto(IIR)digitalfilters.FIRfilterscanbestrictlylinearphase,butbecausethesystemFIRfilterfunctionextremityfixedattheoriginalpoint,itcanonlyusethehighernumberofbandstoachievetheirhighselectivityforthesamefilterdesignindicatorsFIRfiltercalledbandthanafewhigh-IIR5-10times,thecostishigher,Signaldelayisalsolarger.Butifthesamelinearphase,IIRfiltersmustbenetwork-widecalibrationphase,thesamesectionalsoincreasethenumberoffiltersandnetworkcomplexity.FIRfilterscanbeusedtherecursivemethod,notinalimitedprecisionofashock,andintothehomesandquantitativefactorsofuncertaintyarisingfromtheimpactoferrorsthanIIRfiltersmallnumber,andFIRfiltercanbeusedFFTalgorithms,thecomputationalspeed.ButunlikeIIRfiltercanfilterthroughthesimulationresults,thereisnoready-madeformulaFIRfiltermustusecomputer-aideddesignsoftware(suchasMATLAB)tocalculate.So,abroaderapplicationofFIRfilters,andIIRfiltersarenotverystrictrequirementsonoccasions.Unitfromsub-functionscanbedividedintothefollowingfourcategories:(1)Low-filter(LPF);(2)high-filter(HPF);(3)belt-filter(BPF);(4)topreventfilter(BSF).Thefollowingchartdottedlinefortheidealsofthefilterfrequencycharacteristics:2、MATLABintroducedMATLABisamatrixlaboratory(MatrixLaboratory)isintended.Inadditiontoanexcellentvaluecalculationcapability,italsoprovidesprofessionalsymbolsterms,wordprocessing,visualizationmodeling,simulationandreal-timecontrolfunctions.MATLABastheworld'stopmathematicalsoftwareapplications,withastrongengineeringcomputing,algorithmsresearch,engineeringdrawings,applicationsdevelopment,dataanalysisanddynamicsimulation,andotherfunctions,inaerospace,mechanicalmanufacturingandconstructionfieldsplayinganincreasinglyimportantrole.AndtheClanguagefunctionrich,theuseofflexibility,high-efficiencygoalsprocedures.Highlanguagebothadvantagesaswellaslowlevellanguagefeatures.Therefore,Clanguageisthemostwidelyusedprogramminglanguage.AlthoughMATLABisacomplete,fullyfunctionalprogrammingenvironment,butinsomecases,dataandprocedureswiththeexternalenvironmentoftheworldisverynecessaryanduseful.FilterdesignusingMATLAB,couldbeadjustedwiththedesignrequirementsandfiltercharacteristicsoftheparameters,visualsimple,greatlyreducingtheworkloadforthefilterdesignoptimization.Intheelectricitysystemprotectionandsecondarycomputercontrol,manysignalprocessingandanalysisarebasedonarecertaintypessinusoidalwaveandthesecondharmonicsofthesystemvoltageandcurrentsignals(especiallyatDprocess),aremixedwithavarietyofcomplexcomponents,thefilterhasbeeninstalledpowersystemduringthecriticalcomponents.Currentcomputerprotectionandtheintroductionoftwodigitalsignalprocessingsoftwaremainfilter.Digitalfilterdesignusingtraditionalcumbersomeformula,theneedtochangetheparametersafterrecalculation,especiallyinhighfilters,filterdesignworkload.UsesMATLABsignalprocessingboxescanachieverapidandeffectivedigitalfilterdesignandsimulation.MATLABisthebasicunitofdatamatrix,withitsdirectivesexpressionmathematics,engineering,commonlyusedformisverysimilar,itisusedtosolveaproblemthaninMATLABC,FortranandotherlanguagesEndprecisionmuchthesamething.ThepopularMATLAB5.3/Simulink3.0includinghundredsofinternalfunctionwiththemainpackand30typesoftoolkits(Toolbox).kitscanbedividedintofunctionaltoolkitsanddisciplinestoolkit.MATLABtoolkitusedtoexpandthefunctionalsymbolsterms,visualizationmodelingsimulation,wordprocessingandreal-timecontrolfunctions.professionaldisciplinestoolkitisastrongertoolkits,toolkitscontrol,signalprocessingtoolkit,toolkits,etc.belongingtosuchcommunicationsMATLABuserstoopenwidelywelcomed.Inadditiontotheinternalfunction,allthepackagesMATLABtoolkitsarereadabledocumentandthedocumentcouldbeamended,modifiedorusersthroughoriginalprogramtheconstructionofnewprocedurestopreparethemselvesforkits.3、DigitalfilterdesignDigitalfilterdesignofthebasicrequirementsDigitalfilterdesignmustgothroughthreesteps:(1)Identificationofindicators:Inthedesignofafilter,theremustbesomeindicators.Theseindicatorsshouldbedeterminedonthebasisoftheapplication.Inmanypracticalapplications,digitalfiltersareoftenusedtoachievethefrequencyoperation.Therefore,indicatorsintheformofgeneraljurisdictiongivenfrequencyrangeandphaseresponse.Marginskeyindicatorsgivenintwoways.Thefirstisabsoluteindicators.ItprovidesafunctiontorespondtothedemandsofthegeneralapplicationofFIRfilterdesign.Thesecondindicatoristherelativeindicators.Itsvalueintheformofanswerstodecibels.Inengineeringpractice,themostpopularofsuchindicators.Forphaseresponseindicatorsforms,usuallyinthehopethatthesystemwithalinearphasefrequencybandshuman.Usinglinearphasefilterdesignwiththefollowingresponsetotheindicatorsstrengths：①itonlycontainsafewalgorithms,nopluraloperations；②thereisdelaydistortion,onlyafixedamountofdelay;③thefilterlengthN(numberofbandsforN-1),thevolumecalculationforN/2magnitude.(2)Modelapproach:Onceidentifiedindicatorscanuseapreviousstudyofthebasicprinciplesandrelationships,afiltermodeltobeclosertothetargetsystem.(3)Achieved:theresultsoftheabovetwofilters,usuallybydifferentialequations,systemfunctionorpulseresponsetodescribe.Accordingtothisdescriptionofhardwareorsoftwareusedtoachieveit.4、IntroductionofDSPToday,DSPiswidelyusedinthemoderntechnologyandithasbeenthekeypartofmanyproductsandplayedmoreandmoreimportantroleinourdailylifeRecently,NorthwesternPolytechnicalUniversityAviationMicroelectronicCenterhascompletedthedesignofdigitalsignalprocessorcoreNDSP25,whichisaimingatTMS320C25digitalsignalprocessorofTexasInstrumentTMS320series.Byusingtop2downdesignflowNDSP25iscompatiblewithinstructionandinterfacetimingofTMS320C25.Digitalsignalprocessors(DSP)isafitforreal-timedigitalsignalprocessingforhigh-speeddedicatedprocessors,themainvarietyusedforreal-timedigitalsignalprocessingtoachieverapidalgorithms.Intoday'sdigitalagebackground,theDSPhasbecomethecommunications,computer,andconsumerelectronicsproducts,andotherfieldsbaseddevice.Digitalsignalprocessorsanddigitalsignalprocessingisinseparably,weusuallysay"DSP"canalsomeanthedigitalsignalprocessing(DigitalSignalProcessing),isthatinthisdigitalsignalprocessorsLane.Digitalsignalprocessingisacovermanydisciplinesappliedtomanyareasanddisciplines,referstotheuseofcomputersorspecializedprocessingequipment,thesignalsindigitalformforthecollection,conversion,recovery,valuation,enhancement,compression,identification,processing,thesignalsarecompliantform.Digitalsignalprocessorsfordigitalsignalprocessingdevices,itisaccompaniedbyadigitalsignalprocessingtoproduce.DSPdevelopmentprocessisbroadlydividedintothreephases:the20thcenturytothe1970stheorythatthe1980sand1990sforthedevelopmentofproducts.BeforetheemergenceofthedigitalsignalprocessingintheDSPcanonlyrelyonmicroprocessors(MPU)tocomplete.However,theadvantageoflowerhigh-speedreal-timeprocessingcannotmeettherequirements.Therefore,untilthe1970s,atalentmadebasedDSPtheoryandalgorithms.WithLSItechnologydevelopmentin1982wasthefirstrecipientoftheworldgavebirthtotheDSPchip.Yearslater,thesecondgenerationbasedonCMOS工藝DSPchipshaveemerged.Thelate1980s,theadventofthethirdgenerationofDSPchips.DSPisthefastest-growing1990s,therehavebeenfoursuccessivefive-generationandthegenerationDSPdevices.After20yearsofdevelopment,theapplicationofDSPproductshasbeenextendedtopeople'slearning,workandallaspectsoflifeandgraduallybecomeelectronicsproductsdeterminants.中文翻譯數(shù)字濾波器的仿真與實(shí)現(xiàn)隨著信息時(shí)代和數(shù)字世界的到來(lái)，數(shù)字信號(hào)處理已成為當(dāng)今一門(mén)極其重要的學(xué)科和技術(shù)領(lǐng)域。數(shù)字信號(hào)處理在通信、語(yǔ)音、圖像、自動(dòng)控制、雷達(dá)、軍事、航空航天、醫(yī)療和家用電器等眾多領(lǐng)域得到了廣泛的應(yīng)用。在數(shù)字信號(hào)處理應(yīng)用中，數(shù)字濾波器十分重要并已獲得廣泛應(yīng)用。1、數(shù)字濾波器介紹：模擬和數(shù)字濾波器在信號(hào)處理、過(guò)濾功能是一個(gè)不排除局部信息,如隨機(jī)噪音、提取有用的信號(hào)局部,如局部地勢(shì)在一定的頻率范圍.以下方框圖說(shuō)明根本思路.有兩大類(lèi)型的過(guò)濾,模擬以及數(shù)字.他們是完全不同的物理結(jié)構(gòu),如何工作.類(lèi)比電子電路模擬用的過(guò)濾局部組成,例如由電阻、電容、放大器和生產(chǎn)所需的過(guò)濾效果.這種過(guò)濾器被廣泛使用的電路減少噪音等方面的應(yīng)用,提高視頻信號(hào)、圖像均衡的高科技系統(tǒng)等眾多領(lǐng)域.有完善的技術(shù)標(biāo)準(zhǔn)設(shè)計(jì)的模擬電路進(jìn)行過(guò)濾特定要求.在各個(gè)階段,是一個(gè)信號(hào),是電機(jī)電壓和過(guò)濾,目前直接的物理模擬量(例如聲音或視頻信號(hào)和變頻器生產(chǎn))處理.數(shù)碼過(guò)濾用數(shù)字進(jìn)行數(shù)值計(jì)算處理器的信號(hào)抽樣值.處理器的可能通用計(jì)算機(jī)等PC或?qū)I(yè)開(kāi)展方案圖(數(shù)字信號(hào)處理器)芯片.模擬信號(hào)必須先投入使用的取樣和數(shù)碼藝術(shù)開(kāi)展局(模擬到數(shù)字轉(zhuǎn)換器).由此二元多,占抽樣連續(xù)輸入信號(hào)的價(jià)值,轉(zhuǎn)移到處理器,進(jìn)行數(shù)字計(jì)算.這些計(jì)算通常涉及多方面的投入和增加產(chǎn)品價(jià)值的共同因素.如有必要,這些計(jì)算結(jié)果,現(xiàn)在是抽樣信號(hào)值的過(guò)濾,產(chǎn)出通過(guò)開(kāi)展援助委員會(huì)(類(lèi)比數(shù)位轉(zhuǎn)換器來(lái))信號(hào)轉(zhuǎn)換回模擬形式.看到一個(gè)數(shù)字過(guò)濾,信號(hào)是由一系列數(shù)字,而不是電壓或逆流.以下列圖表顯示了這種制度的根本格局：濾波器是指用來(lái)對(duì)輸入信號(hào)進(jìn)行濾波的硬件或軟件。如果濾波器的輸入、輸出都是離散信號(hào)，那么該濾波器的沖擊響應(yīng)也必然是離散的，這樣的濾波器定義為數(shù)字濾波器。數(shù)字濾波器的功能，就是把輸入序列X通過(guò)一定的運(yùn)算變換成輸出序列Y。根據(jù)數(shù)字濾波器沖激響應(yīng)函數(shù)的時(shí)域特性，可將數(shù)字濾波器分為兩種，即無(wú)限長(zhǎng)沖激相應(yīng)IIR濾波器和有限長(zhǎng)沖激響應(yīng)FIR濾波器。IIR數(shù)字濾波器的優(yōu)點(diǎn)是可以利用模擬濾波器設(shè)計(jì)的結(jié)果，而模擬濾波器的設(shè)計(jì)有大量圖表可查，方便簡(jiǎn)單。它的缺點(diǎn)是相位的非線性；假設(shè)需要線性相位，那么要采用全通網(wǎng)絡(luò)進(jìn)行相位校正。圖象處理以及數(shù)據(jù)采集傳輸都要求濾波器具有線性相位特性。而FIR數(shù)字濾波器可以實(shí)現(xiàn)線性相位，又可具有任意幅度特性。從數(shù)字濾波器的單位沖擊響應(yīng)來(lái)看，可分為兩大類(lèi)：有限沖擊響應(yīng)〔FIR〕數(shù)字濾波器和無(wú)限沖擊響應(yīng)〔IIR〕數(shù)字濾波器。FIR濾波器卻可以得到嚴(yán)格的線性相位，然而由于FIR濾波器的系統(tǒng)函數(shù)的極點(diǎn)固定在原點(diǎn)，所以只能用較高的階數(shù)來(lái)實(shí)現(xiàn)其高選擇性，對(duì)于同樣的濾波器設(shè)計(jì)指標(biāo)，F(xiàn)IR濾波器所要求的階數(shù)要比IIR高5至10倍，所以本錢(qián)較高，信號(hào)延遲也較大。但是如果要求相同的線性相位，那么IIR濾波器就必須加全通網(wǎng)絡(luò)進(jìn)行相位校正，同樣也要增加濾波器網(wǎng)絡(luò)的節(jié)數(shù)和復(fù)雜性。FIR濾波器可以用非遞歸的方法實(shí)現(xiàn)，在有限精度下不會(huì)產(chǎn)生振蕩，同時(shí)由于量化舍入以及系數(shù)的不確定性所引起的誤差的影響要比IIR濾波器小的多，并且FIR濾波器可以采用FFT算法，運(yùn)算速度快。但是不象IIR濾波器可以借助模擬濾波器的成果，F(xiàn)IR濾波器沒(méi)有現(xiàn)成的計(jì)算公式，必須要用計(jì)算機(jī)輔助設(shè)計(jì)軟件〔如MATLAB〕來(lái)計(jì)算。由此可知，F(xiàn)IR濾波器應(yīng)用比擬廣，而IIR濾波器那么用在相位要求不是很?chē)?yán)格的場(chǎng)合。濾波器從功能上分又可分為如下4類(lèi):(1)低通濾波器(LPF)；(2)高通濾波器(HPF)；(3)帶通濾波器(BPF)；(4)帶阻濾波器(BSF)。理想濾波器的幅頻特性下列圖虛線為：2、MATLAB介紹：MATLAB是矩陣實(shí)驗(yàn)室〔MatrixLaboratory〕之意。除具備卓越的數(shù)值計(jì)算能力外，它還提供了專(zhuān)業(yè)水平的符號(hào)計(jì)算，文字處理，可視化建模仿真和實(shí)時(shí)控制等功能。MATLAB作為世界頂尖的數(shù)學(xué)應(yīng)用軟件，以其強(qiáng)大的工程計(jì)算、算法研究、工程繪圖、應(yīng)用程序開(kāi)發(fā)、數(shù)據(jù)分析和動(dòng)態(tài)仿真等功能，在航空航天、機(jī)械制造和工程建筑等領(lǐng)域發(fā)揮著越來(lái)越重要的作用。而C語(yǔ)言功能豐富，使用靈活方便，目標(biāo)程序效率高。既有高級(jí)語(yǔ)言的優(yōu)點(diǎn)，又有低級(jí)語(yǔ)言的特點(diǎn)。因此，C語(yǔ)言是目前應(yīng)用最廣的編程語(yǔ)言。雖然MATLAB是一個(gè)完整的、功能齊全的編程環(huán)境，但在某些情況下，與外部環(huán)境的數(shù)據(jù)和程序的交互是非常必須而且有益的。利用MATLAB設(shè)計(jì)濾波器，可以隨時(shí)比照設(shè)計(jì)要求和濾波器特性調(diào)整參數(shù)，直觀簡(jiǎn)便，極大的減輕了工作量，有利于濾波器設(shè)計(jì)的最優(yōu)化。在電力系統(tǒng)微機(jī)保護(hù)和二次控制中，很多信號(hào)的處理與分析都是基于正旋基波和某些整次諧波而進(jìn)行的，而系統(tǒng)電壓電流信號(hào)〔尤其是故障瞬變過(guò)程〕中混有各種復(fù)雜成分，所以濾波器一直是電力系統(tǒng)二次裝置的關(guān)鍵部件。目前微機(jī)保護(hù)和二次信號(hào)處理軟件主要采用數(shù)字濾波器。傳統(tǒng)的數(shù)字濾波器設(shè)計(jì)使用繁瑣的公式計(jì)算，改變參數(shù)后需要重新計(jì)算，在設(shè)計(jì)濾波器尤其是高階濾波器時(shí)工作量很大。利用MATLAB信號(hào)處理箱可以快速有效地實(shí)現(xiàn)數(shù)字濾波器的設(shè)計(jì)與仿真。MATLAB的根本數(shù)據(jù)單位是矩陣，它的指令表達(dá)式與數(shù)學(xué),工程中常用的形式十分相似,故用MATLAB來(lái)解算問(wèn)題要比用C,FO