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LTE-Advanced系统下行MU-MIMO增强技术的研究

STUDYOFENHANCEDⅣrU.MIMOSCHEⅣ匝S

INIJE—AD、厂ANCEDDOWNLINK

ABSTRACT

TocompetewithWiⅣL埙inFourthGenerationofcellularwirelessnetworks.mhasevolvedintoLfE.Advancedtoachievehighertransmissionrates,lowererrorrates,lOWlatencyandbetter

QualityofService.111eprecodingtechnologyprecodesthetransmissionsignalsaccordingtochannelinformationtodolinkadaptationsandachievebettersystemperformance.Ⅳ【U.MIMO(Multi.UserMIMO)iSoneofthekeytechnologiesinm.Advanced.M[1U.MIMOi11I.TE.Advanceddownlinkdenotesthe

MIMOtechnologybywhichmultipleusersreceivemultipledata

streamsfrombasestationswiththesametime—frequencyresources.If

it’scombinedwithbeamformingtechnology,thentheinterferenceamongpaireduserscanbeeffectivelyreducedandspectralefficiencyCanbeincreased,andcorrespondinglyhigherthroughputcanbeachieved.ThispaperstatestheprinciplesofMMOandOFDM,depictsthecharacteristicsandconfigurationsof

m.Advancedand

itschannelmodel.Threeschemesarefurtherproposedinm.Advanceddownlink:thebaselinescheme.Codebook.based

PrecodingSU-M即ⅥO,the

twoenhancedscheme,e.g.,

MU.MIM0.basedMU-CoMP(CoordinateMultiplePoint)andnon.cooperativeMU-Beamformingschemes.Thelatertwoschemes

dependondownlinkchannelinformationto

getjointprecoding

matrix.InTDDsystemthebasestationCangetdownlinkchannelinformationbyuplinkrefe:rencesignalsfrommobilestationdueto

channelreciprocitybetweenuplinkanddownlinkchannels,whileinFDDsystemthereisnosuchchannelreciprocity,thusthedownlinkchannelinformationCanonlybeachievedbythedownlinkaveragecovariancechannelmatrixinthewideband.Accordinglytheir

schedulingand1inkadaptationsareintroducedandtheirperformances

●,

目录

第一章绪论【11…………………………………………………………………………………….11.1MIMo系统增益……………………………………………………………………………l1.1.1SISO,MISO和SIMO系统特点………………………………………………….1

1.1.2MIMO系统的分集增益和复用增益…………………………………………….2

1.1.3MIMO系统波束成形带来的分集增益和阵列增益…………………………….31.2MIMO信道容量…………………………………………………………………………。41.2.1发送端已知信道信息情况下MIMO信道容量…………………………………4

1.2.2发送端未知信道信息情况下MIMO信道容量………………………………….51.3BLAST结构……………………………………………………………………………………………………….61.3.1串行编码的空分复用……………………………………………………………。6

1.3.2V-BLAST(VerticalBellLabsLayeredSpaceTime)…………………………………………7

113.3D-BLAST(DiagonalBellLabsLayeredSpaceTime)………………………………………81.4空时分组编码……………………………………………………………………………81.4.1两根发送天线的空时分组编码…………………………………………………8

1.4.2多根发送天线的空时分组编码【71……………………………………………….91.5解决MIMO信道频率选择性衰落的方法——oFDM[10l……………………………141.5.1OFDM基本原理及其正交性优势………………………………………………14

1.5.2OFDM技术其它优势……………………………………………………………16第二章LTEoAdvanced简介…………………………………………………………………….192.1LTEj亏LTE.Advanced…………………………………………………………………………………………192.1.1LTE简介…………………………………………………………………………………………………19

2.1.1LTE-Advanced简介………………………………………………………………………………….232.2LTE-Advanced场景参数配置及信道模型【12l…………………………………………272.2.1LTE-Advanced仿真场景网络规划及相应大尺度衰落………………………..27

2.2.2LTE-Advanced小尺度衰落MIMO信道模型13】………………………………32第三章LTE-Advanced下行SU.MIMO与MU.MIMO增强技术原理……………………….403.1基于码本的预编码SU-MIMO………………………………………………………。413.1.1基于码本的预编码实现………………………………………………………..42

3.1.2基于码本的预编码最小均方误差(MinimumMeanSquareError)解调………443.2多用户协作多点传输………………………………………………………………….453.2.1多用户协作多点传输概述……………………………………………………一45

3.2.2下行MU-CoMP发送端天线波速成形基本原理……………………………一47

3.2.3下行MU-CoMP调度算法………………………………………………………50

3.2.4外环链路补偿……………………………………………………………………一54

3.2.5单双流自适应……………………………………………………………………。55

3.2.6MUCoMPMMSE检测算法……………………………………………………573.3非协作双流多用户波束成形…………………………………………………………583.3.1非协作双流多用户波束成形概述………………………………………………58

3.3.2非协作双流MU-BeamformingMMSE检测算法……………………………。59第四章LTE-Advanced下行SU.MIMO与MU-MIMO增强技术仿真结果…………………6l4.1L1’E-Advanced下行系统配置…………………………………………………………。614.1.1LTE-Advanced系统帧结构12¨…………………………………………………。6l一一●◆

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