高通RF-Calibration-介绍ppt课件.ppt

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1、RFCalibrationIntroduction.AgendaWhatisRFcalibration.Whycalibration.NVitemsofRFcalibration.RxCalibration.TxCalibration..WhatisRFcalibration•RFcalibrationistheprocessofmeasuringdatatobeusedinthesystemforthepurposeofcompensationofnon-linearcharacteristicsandfrequencyvariation

2、s,andtoprovideabsolutepowerreferenceandtemperaturecompensationtoensureperformanceoftheTxandRxpathsofasubscriberunit.•Outputfromthecalibrationprocessisstoredinnon-volatile(NV)memoryitemsinAMSS.•AMSSusescalibrationvaluesduringnormaloperationtoensuresystemperformanceismet..Se

3、tup:WhatisRFcalibration.WhycalibrationSubscriberunitshavedifferingRFcharacteristicsDifferencesindesignPart-to-partvariationsofcomponentsofthesamedesign.IndividualphonesalsochangetheirownRFcharacteristics:overfrequencychannelovertemperatureWhycalibration.WhycalibrationThesu

4、bscriberunitmustestimatetheRxpowerproperlytomaximizesignal-to-noiseratiosandtoprovideabasisforTxpoweroutput.ThesubscriberunitmusttransmitatcorrectTxpowerleveloveritslargedynamicrange.TheMobileStationModem™(MSM™)deviceandsystemsoftwarecombinationmustknowtheRFandanalogcharac

5、teristicsoftheparticularunit.FailuretocompensatefordifferingRF/analogcharacteristicsmaycausetheunittofailminimumperformancespecifications.Thecompensationvaluesareclassified:StaticRFNVitems:Measuredonceperdesign.CalculatedRFNVitems:RFNVitemsthatarecalculatedbasedonotherpara

6、metersofthedesignconfigurations.MeasuredRFNVitems:IsdeterminedbytheRFcalibrationprocess.NVitemsofRFcalibration.RxcalibrationPhilosophyofRxAGC(AutomaticGaincontrol)loop.DVGA(DigitalVGA)offsetcalibration.LNA(LowNoiseAmplifier)offsetcalibration..Rxcalibration(RxAGCloop)EachRx

7、chainhasitsownreceiver.•ReceivercalibrationprimarilyconsistsofmeasuringtheDVGAoffset(alsocalledVGAgainoffset)andmultipleLNAoffsets,allateachchosenfrequencyindex.•Softwareloadsthefrequency-compensatedDVGAandLNAoffsetvaluesintothehardwareregistersshownabove..PhilosophyofRxDV

8、GAoffsetcalibration:Rxcalibration(DVGAoffset).Rxcalibration(LNAoffset)PhilosophyofRxLNAof