文档介绍：NB--IOT基本概念?Improvedindoorcoverage,supportformassivenumberoflowthroughputdevices,lowdelaysensitivity,ultralowdevicecast,lowdevicepowerconsumption?NB-IOTshouldsupport3differentmodesofoperation:?‘Stand-aloneoperation’utilizingforexamplethespectrumcurrentlybeingusedbyGERANsystemsasareplacementofoneormoreGSMcarriers,aswellasscatteredspectrumforpotentialIoTdeployment.?‘Guardbandoperation’utilizingtheunusedresourceblockswithinaLTEcarrier’sguard-band?‘In-bandoperation’utilizingresourceblockswithinanormalLTEcarrier?180kHzUERFbandwidthforbothdownlinkanduplink?;下行仅支持15kHz的sub-carrierspacing?-Tone;可以提供更大的覆盖,CP较长,对timing要求放松了;?更小的功耗?仅支持type-Bhalf-duplexFDDoperation(type-)?NB-IOTvseMTCvslegacyLTELTER9NB--duplexFDD最大传输速率DL:150Mbps;UL50MbpsDL/UL:<200kbps频带部署方式LTE授权频段带内,带外,保护带三种部署方式覆盖范围(MCL)~145dB164dB子载波间隔DL/UL:15kHzDL:15kHz,UL:-TM9TM1/TM2(单天线或双天线发送分集)同步信号PSS/SSSNPSS/NSSS,构造以及相对间隔都与R9PSS/SSS不同随机接入Preamble/RAR/MSG3/MSG4NPRACH/NPDSCH解调信号DL:CRSUL:DMRSDL:NRSUL:NDMRS上下行信道探测下行CSI,上行SRS没有CSI,没有SRS下行数据信道PDSCHNPDSCHQPSK,16QAM,64QAMPQPSK1/3turbocoding1/H和PDSCH在同一个子帧,占用前几个OS占用单独的下行子帧,HDCIFormat0/1/1A/2/2A/3/3A…DCIFormatN0/N1/N2上行数据信道PUSCHNPUSCH15kHzsub--carrierspacing1/3turbocoding1/3turbocoding单子帧传输一个传输块以ResourceUnit(可以跨多个子帧)作为传输块的传输单位UL-SCH和UCI在同一个子帧发送UL-SCH和UCI在不同子帧发送省电技术DRXPSM,eDRX   ?anonlybedeployedwithinLTEsystem,whileNB-IoThasmoreflexibilityasitcanbedeployedin-band,guardbandandstandalone.?NB-IoTcansupportupto200kdevicespercellper200kHz?TheNB-IoTuplinktransmission(,15kHz)ismuchmoreefficientthaneMTCwidebanduplinktransmission?NB--Band操作的一些特殊处理????SymbolsandabbreviationsNumberofconsecutiveslotsinanULresourceunitforNB--()()Thefollowingnarrowbandphysicalchan