binary phase shift keying the sussex county amateur radio …二进制相移键控苏塞克斯县业余无线电….ppt

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1、Write-Log,BinaryPhaseShiftKeying(PSK31),DigitalPanoramicTuning(DigiPan)andRadioSet-Up.Write-LogClickhertoopenthisbox.Setthefrequencyandmodebeforeoperating.ClickFSKforPSK-31Contacts.Pleasetrynottoforgettoavoidunnecessaryediting.Write-LogSuperCheckPartialEnterCall,OperatingClassa

2、ndSection.TaboverbyusingSpaceBarClickContestthenMultipliersClickWindowthenSuperCheckPartial“AltW”Clearsthisentirerow.Left,RightArrowsandBackspaceallowsforediting.ClickWindowthenBandSummary.NetworkingwilldisplayallStations.LoggedStationsWhatisPSK31?PSK31wasdevelopedbyPeterMartin

3、ez(G3PLX)andintroducedtotheamateurcommunityinDecember1998.PSK31wasalsoknownasVaricodeMode(VariableNumberofBits)Fromtheperspectiveofthetransmitter,thisamountstolittlemorethansomebodywhistlingintothemicrophone.PSK31rapidlyshiftsthephaseoftheaudiosignalbetweentwostates.Theseshifts

4、servethesamefunctionastwoFSKtonestraditionallyusedbyRTTY.Insteadofshiftingfrequencywe’reshiftingphase.PSK31'sbandwidthof31.25 Hzwaschosenbecauseanormaltypingspeedofabout50wordsperminuterequiresabitrateofabout32bitspersecond(1Bit/Hz).PSK31’s31.25 Hzcanbederivedfromthe8 KHzsample

5、rateusedbytheDSPchipsincomputersoundcardsWhatisPSK31?BITValueAmountofShiftDegreesofShift0None0011/21800FrequencyDomainTimeDomainPSK31vs.RTTYThechartattherightshowstheBITErrorRate(BER)asafunctionofSignal-to-Noiseratioinanoiselessenvironment.Note:BERisthenumberofBIT’sreceivediner

6、ror.Forexample,aBERof10-5is1erroneousBITreceivedinerroroutof100,000.ForSignal-to-Noise(S/N)ratiosgreaterthan10dB,PSK-31isvirtuallyerrorfree.S/N=10Log(PoweroftheSignal÷PoweroftheNoise).Inotherterms,ifthenoiselevelis1uVthenyouneed3.16uVfor10dBS/NAtpoorS/NratiostheBERofPSK-31isfiv

7、etimesbetterthanRTTYNotethecurvethatrepresentsQPSK-31.Signal-to-NoiseRatio(dB)BitErrorRatePSK-31RTTYQPSK-31PSK-31PSK31-RealWorldPerformanceThepowerinaPSK-31signalisconcentratedina31.25Hzbandwidthversus250Hz(BWnotfrequencyshift)forRTTYand3300HzforSSB.Assuming100wattsoftransmitpo

8、wer,thePSK-31signalhas3.2watts/Hzvs.30mW/HzforSSB.Ifas