考試資料考試資料考試資料考試資料MIMO學(xué)習(xí)心得EllenwangLTE的7個(gè)傳輸模武中6個(gè)分別應(yīng)用了呱種MIMO技術(shù)方案：傳輸分集(TD),波東K型(Beamforming),空間夏用(SM),多用戶MIMO(MU-MIM0):為普通單天線傳輸模式。TransmitDiversity模式：分2發(fā)送天線的SFBC,和4發(fā)送天線的SFBC+FSTD兩種方案。2發(fā)送天線的SFBC:SFBC是由STBC(SpaceTimeBlockCode)演變而來，由TOFDM-個(gè)slot的符號(hào)數(shù)為奇數(shù),因此不適于使用STBC,但頒域資源是以RB=12個(gè)子裁波來分配的，因此可以用連續(xù)兩個(gè)子裁波來代替連續(xù)兩個(gè)時(shí)域符號(hào)，從而組成SFBC。而當(dāng)使用4發(fā)送天線時(shí),SFBC+FSTD(FrequencySwitchedTransmitDiversity)被果用。SM-openloop,UE僅僅反債信道的Rl(RankIndicator)o此時(shí)基站會(huì)使用CDD(CycleDelayDiversity)技術(shù)。SM-closeloop,UE根搖信jfi估it的結(jié)果反01合適的PMI(PrecodingMatrixIndicator)o(如利用系境容量最大廿算合適的PMI)MU-MIMO,g方案將相同的時(shí)順資源通過空分,分配給不同的用戶。closelooprankl—SMorBF,UEfi慣信道信息使得基站選擇合適的Precoding0UESpecialRS一一BP,和BeamForming的前一種方式不同，迪種方式無需UE反債信道信息，而是基站通il±h信號(hào)進(jìn)行方向估廿，并在下行信號(hào)中插人UESpecialRSO基站可以讓UE匯報(bào)UESpecialRS估it岀的CQIO空間夏用是為了提高傳輸數(shù)據(jù)數(shù)量，基于多碼字的同時(shí)傳輸，HI多f相互獨(dú)立的數(shù)抵流通過映射到不同的層，再由不同的天線發(fā)送出去。碼字?jǐn)?shù)量與天線數(shù)量未必一致。(當(dāng)然天線數(shù)量＞=碼字?jǐn)?shù)量)。傳輸分集主要用于提高信號(hào)傳輸?shù)目煽啃?，例如采用空旳編碼(STC)、循環(huán)琵時(shí)分集(CDD)K天線切換分集等,LTE中用的比般多的是SFBC編碼。傳輸分集(TM2)用來提高信號(hào)傳輸?shù)目煽啃?，壬要是針?duì)小區(qū)邊緣用戶，TM3,TM4J要是甘對(duì)小區(qū)中央的用戶，提髙曄值速率。MU-MIM0是為了提高吞吐量，用于小區(qū)中的業(yè)務(wù)密集區(qū)。TM6,TM7是用于增強(qiáng)小區(qū)覆蓋，也是用于邊塚用戶。不過6是針對(duì)FDD,7是針對(duì)TDD而已。在學(xué)習(xí)MIMO之前，需要理解幾個(gè)基本做念：codeword:相當(dāng)于TranportBlock,即物理層需要傳輸?shù)脑紨?shù)據(jù)快.LTE可支持在同一抉資源同時(shí)傳輸2個(gè)相對(duì)獨(dú)立的codeword,逆是通過空同復(fù)用(SM)技術(shù)實(shí)現(xiàn)的。layer：數(shù)據(jù)被分為不同layerg行傳t,layer總數(shù)＜=天線個(gè)數(shù)。和信道葩陣的rank是對(duì)應(yīng)的。相當(dāng)于空分的ggorank：相當(dāng)于總的layer數(shù)。atennaport：其實(shí)并不等同于天線個(gè)數(shù),而是相當(dāng)于不同的信道估廿參考信號(hào)patterno對(duì)端口0~3,確實(shí)對(duì)應(yīng)多天線時(shí)，RS的發(fā)送pattern；對(duì)于端口4,対應(yīng)fPMCH,MBSFNffi況的RS；對(duì)于竭口5,對(duì)應(yīng)干UESpecialRS。TDD-LTE中支持的傳輸模式使用的DCIformato在每一種模衣中都可以通il改變DCIformat?換到發(fā)射分集模式(TM2),并且TM3、TM4模式下，也支持在不改變DCIformat的悄猊下從空分復(fù)用切換到發(fā)射"集模式(TM2),這時(shí)需要通U在DCIformat中的precodinginformationfield來荷示所使用的precodingmatrixvectorQFrom36.213Table7.1-5Table7.1-5:PDCCHandPDSCHconfiguredbyC-RNTI

Mode2DCIformat1ACommonandUEspecificbyC-RNTITransmitdiversity(seesubclause7.1.2)DCIformat1UEspecificbyC-RNTITransmitdiversity(seesubclause7.1.2)Mode3DCIformat1ACommonandUEspecificbyC-RNTITransmitdiversity(seesubclause7.1.2)DCIformat2AUEspecificbyC-RNTILargedelayCDD(seesubclause7.1.3)orTransmitdiversity(seesubclause7.1.2)Mode4DCIformat1ACommonandUEspecificbyC-RNTITransmitdiversity(seesubclause7.1.2)DCIformat2UEspecificbyC-RNTIClosed-loopspatialmultiplexing(seesubclause7.1.4)orTransmitdiversity(seesubclause7.1.2)Mode7DCIformat1ACommonandUEspecificbyC-RNTIIfthenumberofPBCHantennaportsisone,Single-antennaport,port0isused(seesubclause7.1.1),otherwiseTransmitdiversity(seesubclause7.1.2)DCIformat1UEspecificbyC-RNTISingle-antennaport;port5(seesubclause7.1.1)PDSCHprocessflow:codeword:codeword:資源塊映射天線映射資源塊映射天線映射4-LayermappingNowcodeword-to-layermappingsupport3types:Layermappingfortransmissiononasingleantennaportcodeword-to-1layerLayermappingforspatialmultiplexingantennaports:1codeword-to-1layer2codewords-to-2layers4antennaports:1codeword-to-1layer1codeword-to-2layers2codewo「ds-to-2layers2codewords-to-3layers2codewords-to-4layersTable6.3.3.3-1Table6.3.3.3-1:Codeword-to-layermappingfortransmitdiversity.考試資料考試資料Table6.3.3.3-1Table6.3.3.3-1:Codeword-to-layermappingfortransmitdiversity.考試資料考試資料Table6.3.3.2-1:Codeword-to-layermappingforspatialmultiplexing.Table6.3.3.2-1:Codeword-to-layermappingforspatialmultiplexing.考試資料考試資料NumberoflayersNumberofcodewordsCodeword-to-layermapping11Z(i)=d叫) 臥M%x<0)(0=^(0)(022X⑴⑴=〃⑴⑴21嚴(yán)⑵) 喚 (0>hf0)(221)他沁—Mg"32x⑹⑴=d⑹⑴x⑴(i)=〃山⑵) M霽="黑廠MSLb/2X⑵(i)■〃⑴⑵+1)42』％?)=嚴(yán)⑵)』)(,)=〃他⑵+1)兀⑵(0—⑴⑵)X⑶(0=J(,>(2/+1)Layermappingfortransmitdiversity1codeword-to-2layers(2antennaports)1codeword-to-4layers(4antennaports)

NumberoflayersNumberofcodewordsCodeword-to-layermappingi= ??…咖-I21少⑴=d⑹⑵)曲(i)=護(hù)⑵+1) M器卜嘩J241?0>(°=川:⑷) ⑷映I 器b/4 ifM%od4“f“a)=d3(4j+l)'和廠(M黠匕+2)/4if^bmod4^0,2)(j)=d⑹⑷+2)x⑶⑴=』0)(4曲3) IfM“Lbmod4h0twonullsymbolsshallbeappendedtorf(0)(A/^b-l)4-PrecondingNowprecodingsupport3types:1?Precodingfortransmissiononasingleantennaport2.3.4.Precodingfortransmitdiversity2.3.4.'y(0)(2i)'"10jo'Re(?0>(/))'y⑴⑵)10 -1 0 jRep⑴("嚴(yán)⑵+1)=7T0107Imk<0)(0)V⑴⑵+1)■?■1 0-y0皿⑴(i)iPrecodingwithoutCDD Closed-loopspatialmultiplexingschemeCTM4)?嚴(yán)(曠■?o)(/)'=W(i)嚴(yán))(0PrecodingforlargedelayCDD LargedelayCDDscheme(TM3)?y(o)(/)'?.￥<o>(O"??一嚴(yán)％)_uandd(z)cangetfrombelowtableaccordingtodifferentlayeruTable6.3.4.2.2-1:Large-delaycyclicdelaydiversity.Table6.3.4.2.2-1:Large-delaycyclicdelaydiversity.考試資料考試資料Table6.3.4.2.2-1:Large-delaycyclicdelaydiversity.Table6.3.4.2.2-1:Large-delaycyclicdelaydiversity.考試資料考試資料NumberoflayersuUD(i)11同J 一[:幾31「1111 0-/2刃3幺-川耐3[e"卩g-阿3'1000宀2砂 00 0 小4朋412"11111丁左町4嚴(yán)耐4礦處耐4! €-砂沙屮1嚴(yán)陽丁川刃4e-j網(wǎng)4'10 0 00廠曲4 0 00 0 尹郵 0.0 0 0 嚴(yán)郵.Forw(i)canselectedfromcodebookdefinedin36.211Table6.3.4.2.3-1.Table6.3.4.2.3-1:Codebookfortransmissiononantennaports{oj}.CodebookindexNumberofk1lyersv201'Io'112'11■1-12習(xí);]12_11■J-丿」3一“Ml考試資料考試資料考試資料考試資料110.01J110.01Jmeans1layer codebookindex0 meanstransmitdiversityUEwillreportthesuggestedcodebookindexbyPMIandeNBwillsendthecodebookinfowhicheNBwilluseforPDSCHbyDCI.Fordifferenttransmissionmode,thePMIwillusedifferentnumberofbits.Table7.2-1b:Numberofbitsincodebooksubsetrestrictionbitmapforapplicabletransmissionmodes.Numberofbits2antennaports4antennaportsTransmissionmode324Transmissionmode4664Transmissionmode5416Transmissionmode6416Transmissionmode8632>Transmissionmode3:PMIwilluse2bits—血①For2antennaports:a{means2layers codebookindex0>Transmissionmode4:PMIWillUSe6bits a0a}a2a3a4a5For2antennaports,definedin36.211Table7.2-1c:a0means1layer codebookindex0 means1layer codebookindex1

a2means1layer codebookindex2a.means1layer codebookindex3a4means2layers codebookindex112h-d1'11'212h-d1'11'2L；-丿」Table7.2-1c:AssociationofbitsincodebookSubSetRestrictionbitmaptoprecodersinthe2antennaportcodebookofTable6.3.4.2.3-1in[3].CodebookIndexLNumberoflayersu|20一1AA24?3-4-PrecodinginfoinDCIeNBwillsendtheprecodinginfoinDCIformat2/2A.>Transmissionmode3:DCIformat2A:Precodinginformation-numberofbitsasspecifiedinTable5.3.3.1.5A-1Forantennaports2,theprecodinginformationfieldisnotpresent.Table5.3.3.1.5A-1:Numberofbitsforprecodinginformation.NumberofantennaportsateNodeBNumberofbitsforprecodinginformation2042Thenumberoftransmissionlayersisequalto2ifbothcodewordsareenabled;transmitdiversityisusedifcodeword0isenabledwhilecodeword1isdisabled.ButthePDCCHformatwilluseDCIformat2Anomatterspatialmultiplexingortransmitdiversity.>Transmissionmode4:DCIformat2:Precodinginformation?numberofbitsasspecifiedinTable5.3.3.1.5-3(36.212)Table5.3.3.1.5-3:Numberofbitsforprecodinginformation.NumberofantennaportsateNodeBNumberofbitsforprecodingInformation2346Forantennaports2,thereare3bitsforprecodinginformation,detailinfoseebelowtable:Precodinginfobitfieldmappedtoindex:For2layers:Precodinginfocodebookindex0 0 means2layers-precodingmatrix-1 12[1-I.1 means2layers-precodingmatrix-1 1X means2layers?precodingmatrixusedthelatestPMIreportonPUSCH,usingtheprecoder(s)indicatedbythereportedPMI(s)For1layer:Precodinginfocodebookindex0 0 means 2 layers:Transmitdiversity1 means 1 layer叩recodingmatrix[1 l]7/VI2 means1layer-precodingmatrix[1-1]Z/413 means 1 layer-precodingmatrix[1 j]/414 means1layer叩recodingmatrix[1一/血

means1layer-precodingmatrixwillusethelatestPMIreportonPUSCH.usingtheprecoder(s)indicatedbythereportedPMI(s).ifRl=2wasreported,usingrcolumnmultipliedbyy/2ofallprecodersimpliedbythereportedPMI⑸6latest means1layer-precodingmatrixwillusethe6latestPMIreportonPUSCH?usingtheprecoder(s)indicatedbythereportedPMI(s),ifRl=2wasreported,using2ndcolumnmultipliedbyy2ofallprecodersimpliedbythereportedPMI(s)36.212Table5.3.3.1.5-4:Contentofprecodinginformationfieldfor2antennaports.36.212Table5.3.3.1.5-4:Contentofprecodinginformationfieldfor2antennaports.考試資料考試資料36.212Table5.3.3.1.5-4:Contentofprecodinginformationfieldfor2antennaports.36.212Table5.3.3.1.5-4:Contentofprecodinginformationfieldfor2antennaports.考試資料考試資料Onecodeword:Codeword0enabled,Codeword1disabledTwocodewords:Codeword0enabled,Codeword1enabledBitfieldmappedtoindexMessageBitfieldmappedtoindexMessage02layers:Transmitdiversity02lay?corrpre(12)rs:Precodesponding:odermatri「11'I—1.ngtoX11layer:Precodingcorrespondingtoprecodingvector[1 1]Z/V212lay?corrpre(12)rs:Precodesponding:odermatri1 1■??J一J.ngtoX21layer:Precodingcorrespondingtoprecodervector[1 —l]7/yf222layers:PrecodingaccordingtothelatestPMIreportonPUSCH,usingtheprecoder(s)indicatedbythereportedPMI(s)31layer:Precodingcorrespondingtoprecodervector[1 j]7/V23reserved41layer:Precodingcorrespondingtoprecodervector[1一j]'/a/24reserved51layer:PrecodingaccordingtothelatestPMIreportonPUSCH,usingtheprecoder(s)indicatedbythereportedPMI(s),ifRl=2wasreported,using5reserved1stcolumnmultipliedbyy/2ofallprecodersimpliedbythereportedPMI(s)f-TM7modeFo二「ansmissionmode7-cansupportoneportand?0ports?NumAniennaPortN一iansmissionModenTM7Dc-l—->port5 beamfonningCe-IRS sl/portOD—RS 4/port5BTS三三三三=三三三三三三三三三三三三三三三三三三三三三三三三三三三三三三一NumAniennaPortH2srnsmissionModenTM7Dc-l—VIZport5 Beamolmmg考試資料考試資料槪孩槪孩￥1命/////////////////////////////////////////////////////////////////////////////////////////////////////////LIAIl鋼!|isnfsiapoiusiqiouod~——sa-iRO0pod屮odeuu9|ue-9|0uis o VLIOOZ|/\|l=9pO|/\|UO