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ID:36780283
大小:1.47 MB
页数:51页
时间:2019-05-15
《DS-CDMA系统中多用户检测方法的研究》由会员上传分享,免费在线阅读,更多相关内容在学术论文-天天文库。
1、摘要多用户检测技术是第三代移动通信系统关键技术之一。其主要思想是充分利用所有用户的信息对接收信号做联合检测,抑制多址干扰,缓解“远一近”效应,从而有效地提高系统容量。本文对多用户检测技术进行了初步的研究,并提出了几种新的性能优良的多用户检测器,主要内容如下。提出了一种用于CDMA系统上行链路的自适应检测器,具有了实时性,无需训『练序列,且无需进行大型互相关矩阵的求逆运算,其检测效果与解相关检测器等价。该检测器还可用来进行幅度估计。构造了一种抗“远一近”效应的半盲自适应检测器,其检测性能比非盲的检测器和纯盲的检测器都有所提高。并且提出了一种分组决策反馈半盲检测器,可以降低
2、检测时延。另外,还提出了一种差分编码决策指导(DCDD)盲去相位模糊的方法,并构造了一种新的多径衰落信道下的盲自适应检测器。该检测器无需训练序列,与同类型的基于kalman滤波的去相关自适应RAKE接收机相比,运算量小,检测精度高。本文的工作得到了国家自然科学基金(No.60073053,60133010)的资助。关键词:多用户检测自适应检测幅度估计半盲检测器盲去相位模糊ABSTRACTMutiluserdetectionisoneofthekeytechniquesinthe3Gmobilecommunicationsystems.Themainideabehindi
3、tistomakejointdetectiononthereceivedsignalsbymakingfullUSeoftheinformationofalltheusers’signals,whicheliminatesthemultipleaccessinterference(MAI)andrelaxesthe‘near-far’effect,andconsequentlyincreasesthecapacityofthesystem.Themultiuserdetectionisstudiedinthispaper,andseveralnovelmultiuser
4、detectorswithexcellentperformancearegivenasfollows.AnewadaptivedetectorforuplinkintheCDMAsystemisgiven,withneitherthetrainingsequencesnorthecomputationoftheinvertofcomplexbigco.elationmatrixneeded,andtheperformanceofitisequaltothatofthedecorrelatingdetector.Moreover,itcallbeusedtoestimat
5、etheamplitudesofthesignals.Anovelnear-farresistantsemi-blindadaptivemulfiuserdetectorispresentedandthedetectionperformanceofitisimprovedcomparingwiththeblindandnon·blinddetectors.Meanwhile,agroupdecisionfeedbacksemi-blindadaptivemultiuserdetectorisgivenwhichreducesthedetectiondelays.More
6、over,anovelmethodtoeliminatethephaseillegibility、Ⅳi血differentialcodeddecisiondirectionisprovided,andanewblindadaptivedetectoroverfrequency-selectivefadingchannelsisgiven.ThedetectorCanworkwithouttrainingsequences,anditscomputationalcomplexityisreducedandtheprecisionisimprovedcomparingwit
7、htheblindadaptivedecorrelatingRAKEreceiverbasedontheKalmanfilter.ThispaperissupportedbyTheNationalNaturalScienceFoundationofChina(No.60073053,60133010).Keyword:MultiuserdetectionAdaptivedeteefionAmplitudeestimationSemi-blinddetectorB吐ndphaseillegibilityelimination创新性声明Y58
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