毕业设计(论文)英文原文

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1、编号：毕业设计(论文)外文翻译（原文）院（系）：应用科技学院专业：电子信息工程学生姓名：农惜童学号：0701130204指导教师单位：应用科技学院姓名：赵响职称：讲师2011年6月12日桂林电子科技大学毕业设计（论文）原文用纸第24页共24页AdaptiveMultiuserChannelEstimationusingReducedAbstractThispaperpresentsanadaptivemultiuserchannelestimatorusingthereduced-Kalmanleast-mean-square(R

2、K-LMS)algorithm.Thefrequency-selectivefadingchannelismodeledasatapped-delay-linefilterwithsmoothlytime-varyingRayleighdistributedtapcoefficients.Themultiuserchannelestimatorbasedonminimum-mean-square-error(MMSE)criterionisusedtopredictthefiltercoefficie-nts.Wealsopresenti

3、tsconvergencecharacteristicsandtrackingperformanceusingtheRK-LMSalgorithm.UnlikethepreviouslyavailableKalmanfilteringalgorithmbasedapproach(Chen,ChenIEEETransSignalProcess49(7):1523–1532,2001)theincorporationofRK-LMSalgorithmreducesthecomputationalcomplexityofmulti-use

4、rchannelestimatorusedinthecodedivisionmultipleaccesswirelesssystems.Thecomputersimulationresultsarepresentedtodemonstratethesubstantialimprovementinitstrackingperformanceunderthesmoothlytime-varyingenvironment.Keywords：Kalmanfilter·LMSalgorithm·MMSE·Estimation·Multipat

5、hfading1IntroductionCode-Division-Multiple-Access(CDMA)systemisaspreadspectrumtechnique,whichisbeingwidelyappliedincellularmobileandotherhighdataratewirelesscommunicationsystemsfortheefficientusageofbandwidth.Duringthelasttwodecades,thecommercialuseofmobilecommunicatio

6、nhasincreasedduetothedemandforlargecapacityintermsofthenumberofusers.However,themajorlimitingfactorsforcapacityintheCDMAsystemsareintersymbol-interference(ISI)duetothemultipathpropagationthroughlineardispersivemedia,multipleaccessinterference(MAI)duetotheusageofnon-or

7、thogonalcodes,andadditivewhiteGaussiannoise(AWGN).Onthereverselinkfrommobiletobasestation,thereceivedcompositesignalalsoincludesISIduetothepastsymbolsofotheractiveusers.TheproblemofMAIcanberesolvedusingtheorthogonalcodesinsynchronoussystem.Howeveritbecomesunavoidablef

8、actorunderthemultipathreceptionconditions,becausethesignature(assignedcodetoeachuser)sequencesfordifferentusersarenon-orthog