dsss擴頻接收機的載波跟蹤技術研究

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課題背景及來源........................................................................

10、..............(1)1.2國內(nèi)外研究現(xiàn)狀及分析..........................................................................(1)1.3本文結(jié)構..................................................................................................(4)2擴頻通信

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

12、.................................................(9)2.4動態(tài)環(huán)境給擴頻系統(tǒng)帶來的問題........................................................(17)3載波捕獲及跟蹤設計3.1載波跟蹤方案設計......................................................................

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

14、原理....................................................................................(29)4.2鎖相環(huán)數(shù)學模型分析............................................................................(33)4.3環(huán)路濾波器設計............................