对载波跟踪混合ds跳频扩频测控系统的研究-外文翻译

《对载波跟踪混合ds跳频扩频测控系统的研究-外文翻译》由会员上传分享，免费在线阅读，更多相关内容在工程资料-天天文库。

1、ResearchonCarrierTrackinginHybridDS/FHSpreadSpectrumTT&CSystemAbstractBecauseoftheeffectofcarrierfrequencyhopping,theinputIFsignalofcarriertrackingloopinDS/FHSS(DirectSequence/FrequencyHoppingSpreadSpectrum)TT&C(Telemetry,Tracking&Command)SystemischaracterizedbytheDopplerfrequencyagile・Thetrackin

2、gloopwillshifttothefrequencystepresponsestateceaselesslyandthemeasurementresolutionseverelydecline,eventheloopislikelytobeunlocked.Thispaperpresentsacarriertrackingloopaidedbyfrequencyhoppingpattern.Inordertokeepthestabilityofthetrackingloop,theDopplerfrequencyagilityinthenextfrequencyhoppingdwel

3、lisestimatedandtimelycompensatedtothefrequencyadjustmentofcarrierNCOaccordingtothepresetfrequencyhoppingpatternandcurrentspacecraftvelocity.Simulationresultsshowthatthismethodeffectivelyeliminatestheinstabilityduetocarrierfrequencyhopping,andtheresolutionofloopmeetstherequirementofTT&Csystem.Keyw

4、ords:carriertracking；DS/FHSS；frequencyagility；aided；TT&CI・INTRODUCTIONThemainfunctionofTT&C(Telemetry,TrackingandCommand)systemisrangingandvelocitymeasurement.Presently,themostcommonusedTT&Csystemsareunitcarriersystemandunitspreadspectrumsystem.FortheunitcarrierTT&Csystem,rangingisrealizedbymeasu

5、ringthephasedifferencebetweentransmittedandreceivedtones,andfortheunitspreadspectrumTT&Csystem,accordingtotheautocorrelationpropertiesofPNcode,rangingisrealizedbymeasuringthephasedelaybetweenthereceivedandlocalpseudonoise(PN)code.VelocitymeasurementinbothofTT&Csystemsdependsonextractingthefrequen

6、cydifferenceresultingfromtheDopplerphenomenabetweenthetransmittedandreceivedcarrie匚Whilealltheprocessesmentionedabovearefinishedonthegroundofhighresolutioncarriertracking,andthephaselockloopisthecommonusedmethodtoimplementitinTT&Csystem・Asthespaceelectromagnetismenvironmentbecomemoreandmorecompli

7、cated,thecapabilityofanti-jammingisrequiredbythefutureTT&Csystem[1].SoweconsiderusingthehybridDS/FHSS(DirectSequence/FrequencyHoppingSpreadSpectrum)technologytobuildamorerobustTT&Csystem.FormanyordinaryhybridDS/FHSScom