学习笔记之MIB相关
CORESET0时频域资源位置
SSB块与CORESET0的时频域资源都有很大的灵活性，使用MIB中有限的bit位数"pdcch-ConfigSIB1"（4MSB+4LSB）来表示两者的关系，必须对两者的映射关系做一定约束，也就是协议38.213的table 13-1~13-10与table 13-11~13-15。
MIB ::= SEQUENCE {
systemFrameNumber BIT STRING (SIZE (6)),
subCarrierSpacingCommon ENUMERATED {
scs15or60, scs30or120},
ssb-SubcarrierOffset INTEGER (0..15),
dmrs-TypeA-Position ENUMERATED {
pos2, pos3},
pdcch-ConfigSIB1 PDCCH-ConfigSIB1,
cellBarred ENUMERATED {
barred, notBarred},
intraFreqReselection ENUMERATED {
allowed, notAllowed},
spare BIT STRING (SIZE (1))
}
PDCCH-ConfigSIB1 ::= SEQUENCE {
controlResourceSetZero ControlResourceSetZero,
searchSpaceZero SearchSpaceZero
}
ControlResourceSetZero ::= INTEGER (0..15)
SearchSpaceZero ::= INTEGER (0..15)
ControlResourceSetZero即为4bit MSB，index取值0-15，查38213表table 13-1~13-10可确定符号数、PRB offset等配置；
SearchSpaceZero即为4bit LSB,index取值0-15，查表table 13-11~13-15，可确定SFN、时隙索引、时域相关配置；
以{ssb,pdcch}scs is {30,30}kHZ为例
- For operation without shared spectrum channel access, a UE assumes that the
offsetin Tables 13-1 through 13-10 is defined with respect to the SCS of the CORESET for Type0-PDCCH CSS set, provided by subCarrierSpacingCommon, from the smallest RB index of the CORESET for Type0-PDCCH CSS set to the smallest RB index of the common RB overlapping with the first RB of the corresponding SS/PBCH block. In Tables 13-7, 13-8, and 13-10 Kssb is defined in [4, TS 38.211]. - For operation with shared spectrum channel access, a UE determines an
offsetfrom a smallest RB index of the CORESET for Type0-PDCCH CSS set to a smallest RB index of the common RB overlapping with a first RB of the corresponding SS/PBCH block.
通过Pdcch-configSIB1查表可确定CORESET0与searchspacezero的时频域位置，终端“盲检”PDCCH，接收RMSI（SIB1）
SIB1 ::= SEQUENCE {
cellSelectionInfo SEQUENCE {
q-RxLevMin Q-RxLevMin,
q-RxLevMinOffset INTEGER (1..8) OPTIONAL, -- Need S
q-RxLevMinSUL Q-RxLevMin OPTIONAL, -- Need R
q-QualMin Q-QualMin OPTIONAL, -- Need S
q-QualMinOffset INTEGER (1..8) OPTIONAL -- Need S
} OPTIONAL, -- Cond Standalone
cellAccessRelatedInfo CellAccessRelatedInfo,
connEstFailureControl ConnEstFailureControl OPTIONAL, -- Need R
si-SchedulingInfo SI-SchedulingInfo OPTIONAL, -- Need R
servingCellConfigCommon ServingCellConfigCommonSIB OPTIONAL, -- Need R
ims-EmergencySupport ENUMERATED {
true} OPTIONAL, -- Need R
eCallOverIMS-Support ENUMERATED {
true} OPTIONAL, -- Need R
ue-TimersAndConstants UE-TimersAndConstants OPTIONAL, -- Need R
uac-BarringInfo SEQUENCE {
uac-BarringForCommon UAC-BarringPerCatList OPTIONAL, -- Need S
uac-BarringPerPLMN-List UAC-BarringPerPLMN-List OPTIONAL, -- Need S
uac-BarringInfoSetList UAC-BarringInfoSetList,
uac-AccessCategory1-SelectionAssistanceInfo CHOICE {
plmnCommon UAC-AccessCategory1-SelectionAssistanceInfo,
individualPLMNList SEQUENCE (SIZE (2..maxPLMN)) OF UAC-AccessCategory1-SelectionAssistanceInfo
} OPTIONAL -- Need S
} OPTIONAL, -- Need R
useFullResumeID ENUMERATED {
true} OPTIONAL, -- Need R
lateNonCriticalExtension OCTET STRING OPTIONAL,
nonCriticalExtension SIB1-v1610-IEs OPTIONAL
}
SIB1-v1610-IEs ::= SEQUENCE {
idleModeMeasurementsEUTRA-r16 ENUMERATED{
true} OPTIONAL, -- Need R
idleModeMeasurementsNR-r16 ENUMERATED{
true} OPTIONAL, -- Need R
posSI-SchedulingInfo-r16 PosSI-SchedulingInfo-r16 OPTIONAL, -- Need R
nonCriticalExtension SEQUENCE {
} OPTIONAL
}
UAC-AccessCategory1-SelectionAssistanceInfo ::= ENUMERATED {
a, b, c}
ServingCellConfigCommonSIB ::= SEQUENCE {
downlinkConfigCommon DownlinkConfigCommonSIB,
uplinkConfigCommon UplinkConfigCommonSIB OPTIONAL, -- Need R
supplementaryUplink UplinkConfigCommonSIB OPTIONAL, -- Need R
n-TimingAdvanceOffset ENUMERATED {
n0, n25600, n39936 } OPTIONAL, -- Need S
ssb-PositionsInBurst SEQUENCE {
inOneGroup BIT STRING (SIZE (8)),
groupPresence BIT STRING (SIZE (8)) OPTIONAL -- Cond FR2-Only
},
ssb-PeriodicityServingCell ENUMERATED {
ms5, ms10, ms20, ms40, ms80, ms160},
tdd-UL-DL-ConfigurationCommon TDD-UL-DL-ConfigCommon OPTIONAL, -- Cond TDD
ss-PBCH-BlockPower INTEGER (-60..50),
...,
[[
channelAccessMode-r16 CHOICE {
dynamic NULL,
semiStatic SemiStaticChannelAccessConfig
} OPTIONAL, -- Cond SharedSpectrum
discoveryBurstWindowLength-r16 ENUMERATED {
ms0dot5, ms1, ms2, ms3, ms4, ms5} OPTIONAL, -- Need R
highSpeedConfig-r16 HighSpeedConfig-r16 OPTIONAL -- Need R
]]
}
DownlinkConfigCommonSIB ::= SEQUENCE {
frequencyInfoDL FrequencyInfoDL-SIB,
initialDownlinkBWP BWP-DownlinkCommon,
bcch-Config BCCH-Config,
pcch-Config PCCH-Config,
...
}
BCCH-Config ::= SEQUENCE {
modificationPeriodCoeff ENUMERATED {
n2, n4, n8, n16},
...
}
PCCH-Config ::= SEQUENCE {
defaultPagingCycle PagingCycle,
nAndPagingFrameOffset CHOICE {
oneT NULL,
halfT INTEGER (0..1),
quarterT INTEGER (0..3),
oneEighthT INTEGER (0..7),
oneSixteenthT INTEGER (0..15)
},
ns ENUMERATED {
four, two, one},
firstPDCCH-MonitoringOccasionOfPO CHOICE {
sCS15KHZoneT SEQUENCE (SIZE (1..maxPO-perPF)) OF INTEGER (0..139),
sCS30KHZoneT-SCS15KHZhalfT SEQUENCE (SIZE (1..maxPO-perPF)) OF INTEGER (0..279),
sCS60KHZoneT-SCS30KHZhalfT-SCS15KHZquarterT SEQUENCE (SIZE (1..maxPO-perPF)) OF INTEGER (0..559),
sCS120KHZoneT-SCS60KHZhalfT-SCS30KHZquarterT-SCS15KHZoneEighthT SEQUENCE (SIZE (1..maxPO-perPF)) OF INTEGER (0..1119),
sCS120KHZhalfT-SCS60KHZquarterT-SCS30KHZoneEighthT-SCS15KHZoneSixteenthT SEQUENCE (SIZE (1..maxPO-perPF)) OF INTEGER (0..2239),
sCS120KHZquarterT-SCS60KHZoneEighthT-SCS30KHZoneSixteenthT SEQUENCE (SIZE (1..maxPO-perPF)) OF INTEGER (0..4479),
sCS120KHZoneEighthT-SCS60KHZoneSixteenthT SEQUENCE (SIZE (1..maxPO-perPF)) OF INTEGER (0..8959),
sCS120KHZoneSixteenthT SEQUENCE (SIZE (1..maxPO-perPF)) OF INTEGER (0..17919)
} OPTIONAL, -- Need R
...,
[[
nrofPDCCH-MonitoringOccasionPerSSB-InPO-r16 INTEGER (2..4) OPTIONAL -- Cond SharedSpectrum2
]]
}
FrequencyInfoDL-SIB ::= SEQUENCE {
frequencyBandList MultiFrequencyBandListNR-SIB,
offsetToPointA INTEGER (0..2199),
scs-SpecificCarrierList SEQUENCE (SIZE (1..maxSCSs)) OF SCS-SpecificCarrier
}
通过SIB1可知offsetToPointA的值，计算可知PointA的值。拿大神图镇楼，侵删。
摘自自由之路66
添加链接描述
- offset查表可得，from the smallest RB index of the CORESET0 to the smallest RB index of the common RB overlapping with the first RB of the corresponding SS/PBCH block.
- OffsetToPointA,由基站侧SIB1配置，represents the frequency offset between point A and the lowest subcarrier of the lowest resource block，which has the subcarrier spacing provided by the higher-layer parameter subCarrierSpacingCommon and overlaps with the SS/PBCH block used by the UE for initial cell selection
- Kssb，MIB配置
FR1, kSSB的范围{0，1，2…,23} , 需要5个bit来表示—MIB指示了4bit，剩余1bit在PBCH payload（共8bit）中，详见38.212 clause 7.1.1
FR2, kSSB的范围{0，1，2…,11}， 4bit 足以表示这个范围
NR PBCH内容
NR PBCH的载荷为56bit，24bit高层配置+32bit物理层提供的PBCH，详见下图
总结：
- SSB盲检得到，初始小区接入，UE按20ms的周期检测；
- PointA在SIB1中指示，解析流程为，SSB→PBCH→MIB→Kssb,Offset→Type0-PDCCH→SIB1；
- MIB中的SFN与Kssb会出现结合PBCH附加比特计算的情况；
部分引自
5G NR SSB和CORESET0复用模式
NR PointA