JieYang,CongfengLiu RandomSignalAnalysis Brought to you by | provisional account Unauthenticated Download Date | 1/8/20 9:50 AM Information and Computer Engineering | Volume 2 Alreadypublished intheseries: Volume1 BeijiaNing,AnalogElectronicCircuit, 2018 ISBN978-3-11-059540-6, e-ISBN978-3-11-059386-0, e-ISBN(EPUB)978-3-11-059319-8 Brought to you by | provisional account Unauthenticated Download Date | 1/8/20 9:50 AM Jie Yang, Congfeng Liu Random Signal Analysis | Brought to you by | provisional account Unauthenticated Download Date | 1/8/20 9:50 AM Authors Prof.JieYang Associateprofessor,SchoolofCommunicationandInformation Ai’anUniversityofPost&Telecommunication [email protected] Prof.CongfengLiu Associateprofessor,ResearchInstituteofElectronicCountermeasure XidianUniversity cfl[email protected] ISBN978-3-11-059536-9 e-ISBN(PDF)978-3-11-059380-8 e-ISBN(EPUB)978-3-11-059297-9 ISSN2570-1614 LibraryofCongressCataloging-in-PublicationData Names:Liu,Congfeng,author. Title:Randomsignalanalysis/CongfengLiu. Description:Berlin;Boston:DeGruyter,[2018]|Series:Informationandcomputerengineering| Includesbibliographicalreferencesandindex. Identifiers:LCCN2018026142(print)|LCCN2018029153(ebook)|ISBN9783110593808(electronic PortableDocumentFormatpdf)|ISBN9783110595369(alk.paper)|ISBN9783110593808(e-book pdf)|ISBN9783110592979(e-bookepub) Subjects:LCSH:Signalprocessing. Classification:LCCTK5102.9(ebook)|LCCTK5102.9.L5652018(print)|DDC621.382/2–dc23 LCrecordavailableathttps://lccn.loc.gov/2018026142 BibliographicinformationpublishedbytheDeutscheNationalbibliothek TheDeutscheNationalbibliothekliststhispublicationintheDeutscheNationalbibliografie; detailedbibliographicdataareavailableontheInternetathttp://dnb.dnb.de. ©2018WalterdeGruyterGmbH,Berlin/Boston Coverimage:Prill/iStock/GettyImagesPlus Typesetting:le-texpublishingservicesGmbH,Leipzig Printingandbinding:CPIbooksGmbH,Leck www.degruyter.com Brought to you by | provisional account Unauthenticated Download Date | 1/8/20 9:50 AM Preface Random signals (stochastic signals) arealsoknown asrandomprocesses (stochas- ticprocesses).Itisaquantitativedescriptionofthedynamicrelationshipofaseries ofrandomevents.Randomresearchandotherbranchesofmathematicssuchaspo- tentialtheory,differentialequations,themechanicsandtheoryofcomplexfunctions, andsoon,arecloselylinkedinnaturalscience,engineeringscienceandsocialscience researchineveryfieldofrandomphenomenaisanimportanttool.Randomsignalre- searchhasbeenwidelyusedinareassuchasweatherforecasting,statisticalphysics, astrophysics,managementdecision-making,economicmathematics,safetyscience, populationtheory,reliabilityandmanyfieldssuchascomputerscienceoftenuseran- domprocesstheorytoestablishmathematicalmodels. Inthestudyofrandomprocesses,peopleaccidentlycametodescribetheinher- entlawofnecessityandtodescribetheselawsinprobabilityform,realizingthatthe inevitableisthecharmofthisdiscipline. Thetheoreticalbasisofthewholedisciplineofstochasticprocesseswaslaidby KolmogorovandDub.Thisdisciplinefirstoriginatedfromthestudyofphysics,such asbyGibbs,Boltzmann,Poincareandothersstudyingstatisticalmechanics,andlater Einstein,Wiener,LevyandotherswiththepioneeringworkoftheBrownianmove- ment.Beforeandafter1907,Markovstudiedaseriesofrandomvariableswithspecific dependencies,whichwerelatercalledMarkovchains.In1923,Wienergavethemathe- maticaldefinitionofBrown’smovement,andthisprocessisstillanimportantresearch topictoday. Thegeneraltheoryofstochasticprocessesisgenerallyconsideredtohavebegun inthe1930s.In1931,KolmogorovpublishedtheAnalyticalMethodofProbabilityThe- ory. In 1934,Khintchine published “Thetheory of smooth process,” whichlaidthe theoreticalbasisoftheMarkovprocessandthestationaryprocess.In1953,Dubpub- lishedthefamous“randomprocesstheory,”systematicallyandstrictlydescribingthe basictheoryofrandomprocesses.Atthispoint,thestochasticprocessdevelopedinto asystematicscientifictheory. Inourdailylives,becauseofthepresenceofnoiseandinterference,thesignalswe receiveisnolongeraclearsignal,butarandomprocess;usuallywecallthisarandom signal.Arandomsignalisakindofsignalthatisprevalentintheobjectiveworld.It isvery importantfor college students intheinformationtechnology field to havea deepunderstandingofthestatisticalcharacteristicsandtomasterthecorresponding processingandanalysismethods.Therefore,randomsignalanalysisisanimportant basiccourseinthefieldofelectronicinformation.Throughthestudyofthecourse, studentsaretaughttounderstandthebasicconceptsofrandomsignals,tomasterthe basictheoryofrandomsignals,statisticalcharacteristicsandanalyticalmethods,to learn“statisticalsignalprocessing”or“signaldetectionandvaluation,”withother follow-upcoursesandfuturedevelopmentslayingasolidfoundation. https://doi.org/10.1515/9783110593808-201 Brought to you by | provisional account Unauthenticated Download Date | 1/8/20 9:50 AM VI | Preface ThebookwaswrittenonthebasisofthetextbookRandomSignalAnalysiscom- piledbyProfessorZhangQianwufromXidianUniversity,whichabsorbedtheexpe- riencesofsimilarteachingmaterialsinbrothercollegesanduniversities,andwhich wasfinalizedafteranumberofdiscussionsintheprojectgroup.Thetextbookcharac- teristicscanbesummarizedas: (1)Focusontheconstructionofthewholeknowledgesysteminthefieldofsignal processing. Fromthepointofviewoftheknowledgesystem,themathematicalbasisofrandom signalanalysisis“highermathematics,”“probabilitytheory,”and“linearalgebra,” andaprofessionalbackgroundfrom“signalsandsystems,”thefollowingcoursesare “statisticalsignalprocessing,”or“signaldetectionandestimation.”Therefore,itcon- tinuestostrengthen students’foundationofmathematicalanalysisandtheknown basicconceptofsignalanalysis,basicprinciplesandbasicanalysisandprocessing methods,andatthesametimehelpsstudentstounderstandtheapplicationofran- domsignalanalysismethodstosignaldetectionandparameterestimationwithnoise inthebackground.Thetextbookemphasizestheknowledgesystemandthestructure ofsignalprocessinginitsentirety,soastoavoidstudentslearningandunderstanding randomsignalprocessinginisolation. (2)Continuousrandomsignalanddiscreterandomsequenceanalysis. Traditionalrandomsignalanalysismaterialsmostly focusonthedescription,char- acterizationandanalysisofcontinuousstochasticprocess,oftenignoringtheintro- ductionofdiscreterandomsequences,sothatthestudentsdoingthiscoursecanonly carryouttheoreticalanalysisandderivationandcannotusecomputersforsimulation andemulation.However,makingfulluseofcomputerstoprocessandanalyzerandom signals,ontheonehand,isbeneficialforstudentstoobtainanintuitiveunderstand- ing, and, on the other hand is helpful for students to apply their knowledge, truly combiningtheoreticalresearchandpracticalapplications.Therefore,inthecourseof compilingthetextbook,theanalysisofthediscreterandomsequencewasalsotaken intoconsiderationindetailwhilethecontinuousrandomprocessisanalyzed. (3)Thecombinationoftheoreticalanalysisandexperimentalpractice. Randomsignalanalysisisapracticalcourse,andmostcurrenttextbooksonlyfocus on theoretical teaching instead of experimental practice. This textbook will design thecorrespondingexperimentalcontentforeachchapter,sothatstudentscanunder- standandgraspbasicconcepts,basicprinciplesandbasicmethodsthroughcomputer simulationexperiments. (4)Introductionofthelatestresearchresults. Randomsignalanalysisofexistingteachingmaterialismainlylimitedtothecharac- terizationandanalysisofstationaryrandomprocesseslackadescriptionofnonsta- Brought to you by | provisional account Unauthenticated Download Date | 1/8/20 9:50 AM Preface | VII tionaryrandomprocessesandrelatedanalysisofrandomprocessesafterpassingnon- linear systems. With the advancement of modern signalprocessing, nonstationary, aperiodic,non-Gaussianand nonlinear stochastic signalprocessing problemshave ledtoalotofresearchresults;theseresultsshouldbethebasisofapreliminaryunder- standingoftoday’sundergraduates.Therefore,thistextbookwilldevoteachapterto theintroductionoftime-frequencyanalysisandbasicknowledgeofwaveletanalysis. Thebookisdividedintosixchapters:Chapter0isanintroduction,whichreviews and summarizesthe basicknowledge ofprobability theory and introduces random variables and their related digital features and characteristic functions, as well as otherknowledgepoints.Chapter1introducesthebasicconceptofrandomsignals.It discussestheirbasiccharacteristicsandmethodstodescribethem,complexstochas- tic process. The discrete-time stochastic process are also detailed, and the normal stochastic processand itsspectralanalysisand white noiseprocessareintroduced as well. Chapter 2 introduces the linear transformationof the stationary stochastic process,reviewsthelineartransformationandlinearsystem.Moreover,theprocess ofdifferentialandintegralofrandomprocessisalsointroducedtherein.Thestochas- ticprocessisanalyzedbycontinuousanddiscrete-timesystems.Whitenoiseisana- lyzedbyalinearsystemandthemethodofsolvingtheprobabilitydensityafterthe lineartransformationoftherandomprocess.InChapter3,wediscussthestationary narrowbandstochasticprocessandfirstintroducetheanalyticalprocessandHilbert transform,narrowbandstochasticrepresentation,andtheanalyticcomplexstochas- ticprocess.Wethendiscusstheprobabilitydensityoftheenvelopeandphaseofthe narrowbandnormalprocessandtheprobabilitydensityofthesquareofitsenvelope. Chapter4discussesthenonlineartransformationmethodofstationaryrandompro- cess,includingthedirectmethod,transformationandtheanalysisofthestochastic process through limiters and the method of calculating the signal-to-noise ratio at the outputofthenonlinear system arealsodetailed.Thecharacteristicdescription and analysis method of the nonstationary stochastic process is given in Chapter 5. First, the definition and description of the nonstationary stochastic process are in- troduced,andthecorrelationfunctionandpowerspectraldensityarediscussed.Fi- nally,theanalysismethodofthenonstationarystochasticprocessinmodernsignal processing, such as Wigner–Ville distribution and wavelet analysis are introduced. Thebookincorporatesalargenumberofexamplesandillustrations,andattheend ofeachchapterthereareenoughexercisesforpractice.Italsoprovidessomerefer- enceanswersattheendoftheChinesebook.Thebookalsoprovidesthederivation andproofofsomeimportantformulas,theEnglish–Chineseterminology,andother appendices. The book was completed by associate Professor Yang Jie and Liu Congfeng. OngbwaOllomoArmelonas,aninternationalstudentofXidianUniversity,hasmade great efforts in the translation process of this book. The authors express their ap- preciationtoFuPanlong,YinChenyang,YunJinwei,LiuChenchong,ShaZhaoqun, SuJuan,HouJunrongfortranslatingandcorrectingChapters0,1,2,3,4,5andthe Brought to you by | provisional account Unauthenticated Download Date | 1/8/20 9:50 AM VIII | Preface Appendix,respectively.Thepreparationprocessofthisbookwasencouraged,helped andsupportedbytheXi’anUniversityofPost&TelecommunicationandXidianUni- versitycolleagues.Thesciencepublisherswerestrongsupportinthepublicationof thisbook; PanSisiand other editors dedicated alot ofenergy to the bookand the authorswishtoexpresstheirheartfeltappreciationofthis. Limited to the knowledge of editors, the book fallacies and omissions are in- evitable.Readersareencouragedtooffercriticismandsuggestcorrections. TheEditors 2017.08 Brought to you by | provisional account Unauthenticated Download Date | 1/8/20 9:50 AM Contents 0 Introduction|1 0.1 Probabilityspace|1 0.1.1 Randomizedtrials|1 0.1.2 Samplespace|2 0.1.3 Probabilityspace|2 0.2 Conditionalprobabilityspace|3 0.2.1 Conditionalprobability|3 0.2.2 Multiplicationformula|4 0.2.3 Totalprobabilityformula|4 0.2.4 TheBayesianformula|5 0.3 Randomvariables|6 0.3.1 Theconceptofrandomvariables|6 0.3.2 Discreterandomvariables|7 0.3.3 Continuousrandomvariables|7 0.3.4 Multidimensionalrandomvariables|9 0.4 Distributionofrandomvariablefunctions|13 0.4.1 Distributionofdiscreterandomvariablefunctions|14 0.4.2 Distributionofcontinuousrandomvariablefunctions|14 0.5 Numericalcharacteristicsofrandomvariables|15 0.5.1 Mathematicalexpectations|16 0.5.2 Varianceandstandarddeviation|17 0.5.3 Covarianceandcorrelationcoefficients|18 0.5.4 Themomentofrandomvariables|18 0.6 Characteristicfunctionsofrandomvariables|22 0.6.1 Complexrandomvariables|22 0.6.2 Characteristicfunctionsofrandomvariables|23 0.6.3 Propertiesofcharacteristicfunctions|24 0.6.4 Relationshipbetweencharacteristicfunctionsandmoments|25 0.6.5 Characteristicfunctionsofmultidimensionalrandomvariables|26 0.7 Chebyshevinequalityandthelimittheorem|28 0.7.1 Chebyshevinequality|28 0.7.2 Centrallimittheorem|28 1 Randomprocesses|33 1.1 Basicconceptsofrandomprocesses|33 1.1.1 Definitionofrandomprocesses|33 1.1.2 Probabilitydistributionofrandomprocesses|36 1.1.3 Themomentfunctionofrandomprocesses|40 1.1.4 Characteristicfunctionsofrandomprocesses|43 Brought to you by | provisional account Unauthenticated Download Date | 1/8/20 9:51 AM