通信毕设中英文文献翻译文档格式.doc
《通信毕设中英文文献翻译文档格式.doc》由会员分享,可在线阅读,更多相关《通信毕设中英文文献翻译文档格式.doc(10页珍藏版)》请在冰豆网上搜索。
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