THUWB系统的多用户检测

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1、华中科技大学博士学位论文TH-UWB系统的多用户检测姓名：鲁放申请学位级别：博士专业：通信与信息系统指导教师：黄载禄200611034、对CDMA系统的并行干扰消除（PIC）和部分并行干扰消除（PPIC）检测方法进行分析，将其应用到TH-UWB系统之中。随后提出了基于Turbo思想的迭代SISO多用户检测算法，并分析了算法的渐进有效性，由于充分利用了TH-UWB的信号结构特点，检测算法的复杂度大大降低。在此基础上，利用检测器的误码特性选择合适的加权因子，设计PPIC的迭代SISO多用户检测器，进一步提高了系统的性能。本文还针对以上提出的TH-UWB多用户检测算法进行了计算机仿真，结果表明提出的

2、算法较大程度地提高了接收机的检测性能，且由于算法具有低复杂度的特点，使其在实际系统的应用成为可能。关键词：超宽带，多用户检测，时间分集，最小均方误差，串行干扰消除，并行干扰消除，软入软出IIAbstractUltrawideBand(UWB)communicationtechniquehasattractedgreatinterestsinbothacademiaandindustryforapplicationsinshort-rangewirelesscommunicationsfromtheearly1990s.Ithasbeenproposedasaviablesolutionforh

3、ighspeedindoorrangewirelesscommunicationsystemsbecauseofitslowpower,highrate,immunitytomultipathpropagation,andlesscomplextransceiverhardware.AsintheCDMAsystems,theMAI(MultipleAccessInterference)isthemaininterferenceintheTH-UWB(Time-HoppingUWB)systems,andMUD(MultiuserDetection)isthekeyanti-MAItechno

4、logy.Byadoptingmultiuserdetectiontechnology,TH-UWBsystemscansolvethenear-farproblemandenhancethecapacityofthesystem.FromtheviewofthesignalstructureofTH-UWB,thedifferentcharacteristicsofMAIbetweentheTH-UWBandCDMAsystemsareresearched,andsomelowcomplexitymultiuserdetectorsareproposed.Themainachievement

5、sinclude:1.Takingadvantageofthetimediversitytheory,somelowcomplexitymultiuserdetectorsareproposed.ThefundamentalofthesedetectorsisdifferentfromthatoftheCDMAsystems,andthecomputationcomplexityisreduced.Firstly,thetimediversitydetectorbasedonpulseconflictioncanmitigatetheMAIentirely;secondly,inorderto

6、beappliedtotheasynchronouschannel,amodifiedtimediversitydetectorispresentedtoenhancetheperformance;finally,adetectoradoptingMaximalRatioCombinedtechnology(MRC)ispresented.2.UsingforreferenceoftheSIC(SuccessiveInterferenceCancellation)inCDMAsystems,theSICdetectorsbasedonpulseconfictionisgiven.Thedete

7、ctorrankstheusersaccordingtotheinterferenceoftheusers’pulses:theonewithminimalinterferenceisthefirsttobedetected.Thetimediversitydetectorbasedonpulseconflictionisusedateachstage.Becauseitincreasesthep