GSM 测试技术培训

GSMAgenda„„„MeShare„„GSM„SeparateBandsforUplinkandDownlink„TDMAandFDMAMultiplex„124FrequencyChannels(ARFCN)forGSM900„DLfrequency=ULfrequency+45MHzforGSM900„200kHzChannels„8MobilesshareARFCNbyTDMA„0.3GMSKModulation„270.833kbits/sec.rate123456ARFCN#FrequencyAmplitudeTime01234567Timeslot#FrequencyAmplitudeTimeOvershootLobesduetomodulationRaisedlobesduetorampup„-„„„„•RFCalibrationTest•APC,AGCandAFCcalibration•I/Qtuningcalibration•FinalTest•Call/DataConnectionSetup•TransmitterandReceiverTests•GeneralTests•Batterytests•SIM•Visualcheck(LCD/Keypad)•MicrophoneandEarpieceGSM/GPRSTestPlanTypicalProductionTestsItems„CallProcessing„Call/DataConnectionSetup„Handovers„Call/DataConnectionTermination„GSM/GPRSTransmitterTests„TXPower(CarrierPower)„Powervs.TimePvT(TimeMask)„PhaseFrequencyErrorPFER„OutputRFSpectrumORFS(ModulationandSwitchingTransients)„GSM/GPRSReceiverTests„FastBitErrorRateFBER„OrBitErrorRateBER„BlockErrorRateBLERAgenda„„„„RF„„„TestMode„TypeApprovalLimitsGSM11.10GSM11.10ManufacturersTestModeTerminalapplicationtestRFInterfaceTerminalapplication(PCforexample)communicatestothedeviceviamanufacturersproprietaryconnectionandnon-RFprotocol.Thedeviceisinstructedtotransmitorloop-backinfo.Testsetisthenusedtomakemeasurements.„„„„„„//„RF„TDMAGSM„„„„„„SpectrumduetomodulationandwidebandnoiseSpectrumduetoswitching„„„„„„GSMQIIQ„„„„„„„„PathLossPathLoss„EnoughPowertoOvercomePathLoss„TooMuchPowerDrainsBattery„IncreasedInterference„EnlargedCellSize.Agenda„„„„RF„„„„„--„„„„--GSM„„„TxRx„--GSM„„GSM„„GMSK„/rmsGSMfrequencyerrorphaseerror„frequencyerror0.1ppm„RMSphaseerror=5degrees„Peakphaseerror=20degreesfrequencyerrorphaseerror„I/Q„/„GSMMS„GSMTDMAMSBTSbitTimingAdvanceTDMAapproachrequiressignalstoarriveatBTSatthecorrecttime.Theymustnotoverlap.BTSCellradius≤35kmSignaltravelortime117usec„GSMGSM„GSMGSM„2dB„„21.5dB,1900303111dB„01bitOutputpower()„„TDMATDMA„„Powervs.TimeFrequencyAmplitudeTimePowervs.Timebursttime„„RF(PA)„„“”„ORFSduetoModulationFrequencyAmplitudeTimeOvershootLobesduetomodulationRaisedlobesduetorampupburstfrequency„„„„„dBc„1800kHz„1800kHz6MkHz„I/Q„GSM“RF”„„RFORFSduetoswitchFrequencyAmplitudeTimeOvershootLobesduetomodulationRaisedlobesduetorampupburstfrequency„„„„„„„„„RXLEV„BERRXQUAL„BER„FER„RBERBERRBERBER„„„PRBSPNxxPN9=2^9-1511bits„GSMIIIa3bitsCRCIb3bitsCRC„-102dBm„FERRBER„MS„MS„—„—„SACCH„RXLEVCC+I+N6460~63-110dBm1i-110+idBm„RXQUAL82^3RXLEV&RXQUAL„RXLEV„RXQUALReceiverPerformancewithInterference„BER„GSMGMSK20dB20dBGMSKBER„„„„LO„„RFMeShare„„„GSMMS„„TxRx„„GSMTxRx„TxTx(GSM:925-960MHzDCS:1805-1880MHZPCS:1930-1990)„RxRx(GSM:880-915MHzDCS:1710-1785MHZPCS:1805-1880)Tx“”1„RxTxGSM900CS1800„GSMDCS1800DCS1800GSM„100KHz12.75GHz„