dsss擴(kuò)頻接收機(jī)的載波跟蹤技術(shù)研究

1、AbstractSpreadspectrumcommunicationsystemhastheadvantageofthesafetyofcommunicationconcealmentofinfmationantiinterferencesoon.Therefethefieldofdigitalcommunicationbecomespopularintheenvironmentofsecrecycommunicationbadele

2、ctromagismbecomeshotspotofwirelesscommunicationgradually.Therefepeoplepaymemeattentiontotheresearchofthehighpoweredspreadspectrumreceiver.BecauseoftheeffectofDopplerthefrequencyshiftbetweenthelocalcarrierreceivingcarrier

3、fluctuatesheavilywhichhavebroughtgreatdifficultyoftrackingsynchronizationofcarrier.Thepaperhasresearchedinallusiontothetheeticalpracticalproblemwhichcomesacrossintheprocessofresearchingdirectsequencespreadspectrumreceive

4、ranalyzedtheinfluencewhichisbroughtalongthatDopplertothetrackingsynchronizationtrackingaccuracyoflocalcarrierdiscussedthedigitalrealizationofphaselockedloop.Thepaperhasexpoundedtherationaleofcarrierresumingofspreadspectr

5、umreceiverintheaspectofcompositionofcarrierresumingsystemmathematicmodelprimecapabilityindextrackingschemefrequencylockedloopphaselockedloopsoonemphasizetheeticalanalysissimulatedstudyofAFCCostastwoloopsswitch.Thepaperha

6、sanalyzedthetrackingschemeofFLLPLLdesignstheloopfilterfphaselockedloopmeanwhileexplainsitsdigitalrealizedmethod.IntheendwehavebuiltthemodelofspreadspectrumcommunicationsystemfsimulationthroughSPWsimulationsoftwaredesigne

7、dcarriertrackingmodelofdirectsequencespreadspectrumreceivergotthestatisticalerrofcarrierwavetrackinginthesituationofdifferentDopplerfrequencyshiftDopplerchangeratesvalidatedtheabovetheeticalanalysisdesign.Resulthasindica

8、tedthatthisdesignschemesolvedthisproblemwell，whichisbroughtbyeffectofDopplerisabletofulfilltherequestoftrackingaccuracy.目錄摘要................................................................................................

9、................IAbstract............................................................................................................II1緒論1.1課題背景及來(lái)源........................................................................

10、..............(1)1.2國(guó)內(nèi)外研究現(xiàn)狀及分析..........................................................................(1)1.3本文結(jié)構(gòu)..................................................................................................(4)2擴(kuò)頻通信

11、介紹2.1擴(kuò)展頻譜技術(shù)原理..................................................................................(5)2.2直接序列擴(kuò)頻系統(tǒng)..................................................................................(7)2.3擴(kuò)頻信號(hào)的同步捕獲與跟蹤技術(shù).........

12、.................................................(9)2.4動(dòng)態(tài)環(huán)境給擴(kuò)頻系統(tǒng)帶來(lái)的問(wèn)題........................................................(17)3載波捕獲及跟蹤設(shè)計(jì)3.1載波跟蹤方案設(shè)計(jì)......................................................................

13、..........(18)3.2叉積自動(dòng)頻率控制CPAFC...................................................................(19)3.3雙環(huán)切換方案.........................................................................................(26)4PLL鎖相環(huán)設(shè)計(jì)4.1鎖相環(huán)工作

14、原理....................................................................................(29)4.2鎖相環(huán)數(shù)學(xué)模型分析............................................................................(33)4.3環(huán)路濾波器設(shè)計(jì)............................