NB-IOT原理及测试

NB-IOT原理及测试李强[e-mail]内容ıNB-IOT技术背景ıNB-IOT标准化过程ıNB-IOT布网模式及双工方式ıNB-IOT无线帧结构和下行物理信道ıNB-IOT无线帧结构和上行物理信道ıNB-IOT上下行调度及深度覆盖ıNB-IOT应对物联网海量接入和低功耗机制ıNB-IOT测试内容ıNB-IOT技术背景ıNB-IOT标准化过程ıNB-IOT布网模式及双工方式ıNB-IOT无线帧结构和下行物理信道ıNB-IOT无线帧结构和上行物理信道ıNB-IOT上下行调度及深度覆盖ıNB-IOT应对物联网海量接入和低功耗机制ıNB-IOT测试IOT市场趋势IOT主要无线技术IOT产品要求IOT产品成本NB-IOT需求背景NarrowbandInternetofThingCIOT市场NB-IOT技术优势NB-IOT技术优点内容ıNB-IOT技术背景ıNB-IOT标准化过程ıNB-IOT布网模式及双工方式ıNB-IOT无线帧结构和下行物理信道ıNB-IOT无线帧结构和上行物理信道ıNB-IOT上下行调度及深度覆盖ıNB-IOT应对物联网海量接入和低功耗机制ıNB-IOT测试NB-IOT标准化过程eMTC3GPP主要IOT技术参数对比3GPP主要IOT技术参数对比NB-IOTvs.eMTCıeMTCcanonlybedeployedwithinLTEsystem,whileNB-IoThasmoreflexibilityasitcanbedeployedin-band,guardbandandstandalone.ıNB-IoTcansupportupto200kdevicespercellper200kHzıNB-IoTuplinktransmission(3.75kHz,15kHz)ismuchmoreefficientthaneMTCwidebanduplinktransmissionıNB-IoThasabout6.3dBbettercoveragethaneMTCıNB-IoTisthefoundationforNarrowband5G;continuingtoevolveinRelease14+ResourceThepathto5GThepathto5G内容ıNB-IOT技术背景ıNB-IOT标准化过程ıNB-IOT布网模式及双工方式ıNB-IOT无线帧结构和下行物理信道ıNB-IOT无线帧结构和上行物理信道ıNB-IOT上下行调度及深度覆盖ıNB-IOT应对物联网海量接入和低功耗机制ıNB-IOT测试NB-IOT系统带宽NB-IOT部署模式NB-IOT多载波模式ıAnchorcarrierwithNB-PSS/SSS,NB-PBCHNB-IOT100kHzrasteroffsetforin-band例如对于10MHz带宽的LTE，NB-IOT既不能占用同步和广播信道所在的PRB，又要满足100kHzraster要求，因此其带内NB-IOT只能位于4,9,14,19,30,35,40,45号PRB，而且要做2.5kHzoffsetNB-IOTrasteroffsetindicatedbyNB-MIBPRBindexingforNB-IoTin-bandoperationıPRBindexingoffsetisfromthemiddleoftheLTEsystemı5bitsareusedtoindicatetheindexasgiveninthetableNB-IoT:Channelraster-rasteroffset-guardbandNB-IOT双工模式ı只支持half-duplexFDDtypeBNB-IOT双工方式的优点ı降低了终端成本和功耗内容ıNB-IOT技术背景ıNB-IOT标准化过程ıNB-IOT布网模式及双工方式ıNB-IOT无线帧结构和下行物理信道ıNB-IOT无线帧结构和上行物理信道ıNB-IOT上下行调度及深度覆盖ıNB-IOT应对物联网海量接入和低功耗机制ıNB-IOT测试NB-IOTDownlinkOFDM参数ı下行基于OFDMA,FF点数=128,基带采样速率1.92MHz,子载波间距15kHz,有效带宽180kHz=1PRBıCPlength=10/9samplesNB-IOT时隙结构和RE资源ı只支持kHz15fNB-IOTDownlink基带信号12/2/)2/1(2)(,)(RBscRBscs,CP)(NNkTNtfkjplkplleats2/12)(,12/2)(,)(RBscDLRBs,CP)(RBscDLRBs,CP)(NNkTNtfkjplkNNkTNtfkjplkpllleaeatsNB-IOTDownlink基带信号：LTEDownlink基带信号：NB-IOT和LTE基带信号差别：NB-IOT下行基带使用了DC载波并且具有频域具有半载波频移以降低射频链路直流泄露的影响，与LTE的上行基带处理方式类似NB-IOT物理信道NB-IOT下行物理信道和物理信号NB-IoT:NPSS与传统LTEPSS不同，NPSS不携带任何小区信息NB-IoT:NSSSSynchronizationsignalsNRSıTherearetwoNB-IoTdownlinktransmissionschemesdefinedinalloperationmodes:•Singleantennaport(port0)•Twoantennaports(ports0and1),usingtransmitdiversity,i.e.SFBCıSametransmissionschemeisappliedtoNPDCCH,NPBCH,andNPDSCHNB-IoT:BroadcastingofSystemInformationıMasterinformationbroadcastandsysteminformationbroadcastaresupportedforNB-IoTNB-IoT:NB-MIBNB-IoT:NB-MIBInnormalLTE,MIBcarriesverysimplesetofinformation.However,inLTE-NBMIBcarriesrelativelylargesetofinformation.Itcarriesfollowinghighlevelinformation:ı4bitsindicatingthemostsignificantbits(MSBs)oftheSystemFrameNumber(SFN),10bitsisneededtoindicate1024frames,others6bits?ı2bitsindicatingthetwoLSBsofthehyperframenumberı4bitsfortheSIB1-NBschedulingandsize,(InlegacyLTE,SIB1decodinginformationisconfiguredbyDCI1A,notbyMIB)ı5bitsindicatingthesysteminformationvaluetagı1bitindicatingwhetheraccessclassbarringisappliedı7bitsindicatingtheoperationmodewiththemodespecificvaluesincludingrateroffsetı11sparebitsforfutureextensionsNB-IOTNPBCHLTEPBCHTTI为40ms，频域占用中心72个子载波，时域为Slot1的前4个符号NB-IOTNPBCHı和LTE一样，NB-PBCH端口数通过CRCmask识别，区别是只支持1和2端口。NB-IOT在解调MIB信息过程中确定了小区天线端口数ı在三种operationmode下，NB-PBCH均不使用前3个OFDM符号。In-band模式下NB-PBCH假定存在4个LTECRS端口，2个NB-RS端口进行速率匹配。NB-IoT:SystemInformationBlockType1ıSIB1-NBwithafixedperiodicityof2560ms(256RadioFrames)Cellaccess/selection,otherSIBschedulingControlregionsize(noPCFICH)forin-bandcase(guardbandandstandalone=0)NB-IoT:SystemInformationBlockType1NPDCCHıNPDCCH的符号起始位置：对于in-band，起始位置包含在SIB2-NB中；对于stand-alone和Guardband，起始位置统一为0ıNCCE：narrowbandcontrolchannelelementsNPDSCHıNPDSCH的符号起始位置：对于in-band，如果是SIB子帧，起始位置为3，非SIB子帧，起始位置包含在SIB2-NB中；对于stand-alone和Guardband，起始位置统一为0NB-IOTDLsignalNB-IOT下行信号处理流程NPSSTimingandinitialCFONSSSGetNB-PCIDandNRSstructureNPBCHSFN,antennaportsnumber,SIB1-NB,operationmodeNPDCCHNPDSCHNB-IOTDLsignal内容ıNB-IOT技术背景ıNB-IOT标准化过程ıNB-IOT布网模式及双工方式ıNB-IOT无线帧结构和下行物理信道ıNB-IOT无线帧结构和上行物理信道ıNB-IOT上下行调度及深度覆盖ıNB-IOT应对物联网海量接入和低功耗机制ıNB-IOT测试NB-IOTSingle-ToneWithinSTFlexiblebandwidthof3.75kHzand15kHzadaptivetodifferentscenariosı3.75kHz:•providesbettercoveragewithrelaxedtimingrequirementsduetolongerCPlength•bettercapacityforlargecellPRACHandPUSCHlinks•lowerpowerconsumptionı15kHz:•bettercoexistwithlegacyLTElinksNB-IOTUplinkNB-IOTuplinksupportSingle-ToneandMulti-ToneandUEmustreportitsabilityıSingle-Tone•Include3.75kHzand15kHzbandwidth•Acyclicprefixisinserted•FrequencydomainSincpulseshapinginthephysicallayerdescription•Bettercoverageandpowerconsumption•EnablesextremelowcostIoTterminalstocompetewithnon-cellulardevices•Enablefastertimetomarket.•Notonlycellularindustry,lowcostchipvendorsareinterestedinbuildingSTonlychips.ıMulti-Tone•SC-FDMA•Higherpeakrate•AdditionalmechanismsforPAPRreductionFFS•BasedonSC-FDMAwiththesame15kHzsubcarrierspacing,0.5msslot,and1mssubframeasLTENB-IOTupl