通信毕设中英文文献翻译.doc

通信毕设中英文文献翻译.doc

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英文文献

TheApplicationofonepointMultipleAccessSpreadSpectrumCommunicationSystem

LiuJiangang,NanyangCity,HenanProvinceElectricPowerIndustryBureau

【ABSTRACT】SpreadSpectrumDigitalMicrowavecommunicationasacommunication,becausetheirexcellentperformancehavebeenwidelyused.ThearticleinNanyangCityPowerIndustryBureauonepointMultipleAccessSpreadSpectrumCommunicationSystemasanexample.briefedthespreadspectrumcommunications,thebasicconceptandcharacteristicsofthepowersystemcommunicationapplications

.KEYWORDS：

onepointmultipleaccess;Spread-spectrumcommunication;Attenuation

NanyangCityintheoutskirtsofCentralcloth35to11kvsubstationfarmterminals,theiroperationmanagementrightsbelongtotheCouncilEast,RuralPowerCompanywest（theeasternsuburbofagriculturalmanagementcompanies--four,thewesternsuburbsofRuralPowerCompanyManagement7）,SchedulingofthevariousstationsofthemeansofcommunicationtotheoriginalM-150radioandtelephoneposts.2002Withthetransformationofruralnetwork,theremotestationequipmentintooperationandcommunicationchannelstoputahigherdemand.AsPUCDispatchCommunicationBuildingtotheeastandwestoffarmers--thedifferencebetweenacompanylinkedtofiber,Therefore,if11substationsandtheestablishmentofatransferLinkBuildinglinksPointmaybethedataandvoiceweresenttotworuralpowercompaniesdispatchroom,RuralNetworkschedulingfortheimplementationofautomationtocreatethenecessaryconditions.

Giventhestatusandpowergridsubstationlevel,nature,takingintoaccountthecarrierandoptical-fibercommunicationstoconductmultipleforwarding,increasingtheinstabilityfactor,consideringthecostandconditionsoftheurbanconstruction,Finallydecidedtoadoptwirelessspread-spectrumtechnologytoestablishthat11farmterminalsubstationcommunicationsystem.Thispaperdescribesthespreadspectrumtechnologyandthecurrentsystemofthebuilding.

1.Thebasicconceptofspread-spectrumcommunication.

SpreadSpectrumCommunication'sbasiccharacteristics,isusedtotransmitinformationtothesignalbandwidth（W）isfargreaterthanthepracticalinformationrequiredminimum（effective）bandwidth（△F）,astheratioofprocessinggainGP.

GP=W/△F

Asweallknow,theordinaryAM,FM,orpulsecodemodulationcommunications,GPvaluesintheareamorethan10times,collectively,the"narrow-bandcommunication",andspread-spectrumcommunicationsGPvaluesashighashundredsoreventhousandsoftimes,canbecalled"broadbandcommunications."

Duetothespread-spectrumsignal,itisverylowpowertransmitters,transmissionspacemostlydrownedinthenoise,itisdifficulttointerceptedbytheotherreceiver,onlyspreadingcodeswiththesame（orrandomPNcode）receiver,Gaincanbedealtwith,anddispreadingresumetheoriginalsignal.

2.Thetechnologysuperiorityofspread-spectrumcommunication.

Stronganti-interference,biterrorrateislow.Asnotedabove,thespreadspectrumcommunicationsystemduetotheexpansionofthetransmittersignalspectrum,thereceiverdispreadingreductionsignalproducedspreadinggain,therebygreatlyenhancingitsinterferencetolerance.Underthespreadinggain,orevennegativeinthesignal-to-noiseratioconditions,canalsosignalfromthenoisedrownedoutExtraction,inthecurrentbusinesscommunicationssystems,spreadspectrumcommunicationisonlyabletoworkinanegativesignal-to-noiseratioundertheconditionsofcommunication.

Anti-multi-pathinterferencecapability,increasethereliabilityofthesystem.Spread-spectrumsystemsasusedinthePNhasagoodcorrelation,correlationisveryweak.differentpathstothetransmissionsignalcaneasilybeseparatedandmayintimeandre-alignmentphase,formationofseveralsuperimposedsignalpower,therebyimprovingthesystem'sperformancetoreceiveincreasedreliabilityofthesystem.

Easytousethesamefrequency,improvingthewirelessspectrumutilization.Wirelessspectrumisveryvaluable,althoughlong-wavemicrowavehavetobeexploited,andstillcannotmeettheneedsofthecommunity.Tothisend,countriesaroundtheworldaredesignedspectrummanagement,userscanonlyusethefrequencyapplications,relyonthechanneltopreventthedivisionbetweenthechannelinterference.

Duetotheuseofspread-spectrumcommunicationrelatedreceivethishigh-tech,lowsignaloutputpower（"aW,asageneral-100mW）,andwillworkinthechannelnoiseandthermalnoiseinthebackground,easytoduplicateinthesameareausingthesamefrequency,cannowallsharethesamenarrow-bandfrequencycommunicationsresources.

Spreadspectrumcommunicationisdigitalcommunications,particularlyfordigitalvoiceanddatatransmissionwhile,spreadspectrumcommunicationwiththeirow