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1、细说移动通信中的新技术(Anewtechnologyinmobilecommunication)Aspeople'slivingspace,activityspaceandparticipationareascontinuetoexpand,thefunctionalrequirementsofmobilephones,notonlydialogueandcommunication,therearemanyotherfunctions.Moreover,theexistingcommunicationsystemthereexistmanyunsa
2、tisfactoryplaces,suchassystemcapacity,voicedistortion,droppedonline,powerradiationandslowdatatransmission,theexistingcommunicationtechnologyaloneisnotenoughtomeetthenewdemandsofcommunicationpeople.Sointhiscase,wemusthavenewcommunicationtechnologytoensure,sothatavarietyofemergi
3、ngcommunicationtechnologycameintobeing,belowissomeofthe3Gcommunicationsmaybeusedinthenewtechnology.1.ChannelcodinganddecodingtechnologyThistechniquemaybeusedintheDS-CDMAcommunicationstandard,inwhichchannelcodinganddecodingismainlytoreducethesignaltransmissionpowerandsolvethein
4、evitablefadingproblemofthesignalinthewirelesscommunicationenvironment.TheuseofcodectechnologycombinedwithinterleavingcanimprovetheBERperformance,comparedwithnoencoding,convolutionalcodescanimprovethebiterrorrateistwoordersofmagnitudereached10-3~10-4,andtheDS-CDMAcommunications
5、ystemusingTurbocodeerrorratecanbeincreasedto10-6.DS-CDMAcandidatechannelcodingtechniquesincludeReed-SolomonandTurbocodes,andTurbocodescanbeusedas3GdataencodinganddecodingtechnologybecausetheencodinganddecodingperformancecanapproachtheShannonlimit.Convolutionalcodesaremainlyuse
6、dforlowdataratespeechandsignaling.2.SmartantennatechnologyInthedevelopmentofmobilecommunicationtechnology,smartantennahasbecomeoneofthemostactivefields.Inrecentyears,almostalladvancedmobilecommunicationsystemswillusethistechnology.Theadvantageofsmartantennatechnologytomobileco
7、mmunicationsystemisdifficulttoreplacebyanytechnologyatpresent.Smartantennatechnologyhasbecomeoneofthemostattractivetechnologiesinmobilecommunications.Smartantennatechnologyusesadaptivebeamformingtechnologytoimprovetheuser'sdirectionofarrivalgain,whileusingthezeroofthepatternto
8、reducetheinterferenceofhigh-powerusersonthespace.Itsmaindiffi