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1、摘要锁相环是一个能够跟踪输入信号相位变化的闭环自动跟踪系统。它广泛应用于无线电的各个领域,并且,现在已成为通信、雷达、导航、电子仪器等设备中不可缺少的一部分。根据虚拟无线电技术的特点和锁相环的基本原理,提出一种适于计算机软件化实现的锁相环数学模型,分析不同参数对锁相环捕获和跟踪性能的影响,得出不同情况下参数设定的基本准则。计算机仿真结果表明,软件锁相环在加性高斯白噪声信道下具有较好的捕获与跟踪性能。最后提出软件锁相环在测控系统中实现信号实时处理的优化方借助于MATLAB中的Simulink仿真软件,在Simulink中
2、利用仿真模块搭建了全数字锁相环的仿真模型。先借助模拟锁相环直观形象、易于理解的特点,通过锁相环在频率合成方面的应用,先对模拟锁相环进行了仿真,对锁相环的工作原理进行了形象的说明。在模拟锁相环的基础上,重新利用仿真模块搭建了全数字锁相环的仿真模型,通过仿真达到了设计的目的,验证了此全数字锁相环完全能达到模拟锁相环的各项功能要求。关键词:锁相环,压控振荡器,锁定,MATLAB,Simulink,频率合成,仿真模块ABSTRACTPhase-lockedloopisaclosedloopfrequencycontrolsys
3、tem,whichfunctioningisbasedonthephasesensitivedetectionofphasedifferencebetweentheinputandoutputsignalsofthecontrolledoscillator.Ithasbeenwidelyusedinallaspectsinradiofieldand,hasbecomedaindispensablepartincommunication、radar、nevigationandelectronicequipments.Bu
4、twiththedisigncomplexityofphase-lockedloopinworks,therewillmeetalotofdatasandalongsimulationtimeifsimulatingthePLLwithSPICE,whatisworse,whichneedtosimulateseveraltimestoextractthedisignparameters,atthatway,thedisigntermwillbeextended.Withthehelpofflexibilityandp
5、alpabilityofMatlab’ssimulink,thebehavioralmodelofDPLLisbuildedusingtheblockinsimulinkbasedonthefrequencysysthesis.ThroughtheDPLLapplicatinginfrequencysysthesis,theprincipleofphase-lockedloopandtheworkprocessissimulated.AccordingtothecharacteristicsoftheVirtualRa
6、diotechnologyandthebasictheoryofthePhaseLookLoop(PLL),thispaperputsforwardthemathematicalmodelofthePLLwhichissuitableforsoftwarerealizationbythecomputer.Inthispaper,theinfluencesoftheparameterstothecaptureperformanceandthetrackingperformanceareanalyzed,andthebas
7、icprincipleoftheparametersettingindifferentconditionsisgiven.TheresultsofthesimulationprovethatthecaptureperformanceandthetrackingperformanceofSoftwarePLLinAdditiveWhiteGaussianNoisearegood.Atthelastofthepaper,theoptimizedmethodofthePLLsignalrealtimeprocessingin
8、theTracking,TelemeteringandControlSystemispresented.KEYWORDS:MATLAB,phase-lockedloop,Voltage-controlledoscillator,locked,simulink,frequencysysthesis,simulationmodel