Cell Acquisition - Camping On LTE

Now to initiate a registration UE do need to aquire MIB and SIB1 and SIB2, which in technical term we say as Initial Acquisition - in order to do so UE need to sync it self with NW by synchronizing FRAME and SLOT wise by reading PSS and SSS.

During Initial Acquisitaion , we often say PLMN selection and Cell serach and some time confused between this two.
Just to clear the confusiion if we remeber that SIB1 carried PLMN and to read or acquire PLMN e actually need SIB1 and to get SIB1 we need to perform cell search.



PSS-> Synchronization Signals
Use fullness-
1. Sub Frame
2. Slot
3. Symbol Synchronization
Above 3 in the time domain,
4. Identify center of the channel bandwidth
Above in the frequency domain.
5. Deduce Physical Cell ID (PCI) 1 of 3

Location-
FDD- Central 62 sub-carrier , last symbol of sub-frame 0(sub-frame 0) and 10(sub-frame 5)
TDD- Central 62 sub-carrier , 3rd symbol of time slot 2(sub-frame 1) and time slot 12 (sub-frame 6)


SSS->
Usefullness-
1. Deduce Physical Cell ID Group (PCI Group) 1 of 168
So combined with PSS this helps to determine the PCI.
Location-
FDD- Central 62 sub-carrier , Second last symbol of sub-frame 0(sub-frame 0) and 10(sub-frame 5)
TDD- Central 62 sub-carrier , last symbol of time slot 1(sub-frame 0) and time slot 11 (sub-frame 5)

PSS/SSS in FDD

PSS/SSS in TDD

PSS/SSS Overhead as signalling in FDD

C-RS-> Cell Specific RS
1. Channel Estimation

for correct demodulation of down-link channel , UE required channel estimation. For which we need C-RS. This are known cell-specific reference symbols.

MIB-> Master Information Block

MasterInformationBlock ::= SEQUENCE {
dl-Bandwidth ENUMERATED {
n6, n15, n25, n50, n75, n100},
phich-Config PHICH-Config,
systemFrameNumber BIT STRING (SIZE (8)),
spare BIT STRING (SIZE (10))
}

SIB1-> System information Block 1


SystemInformationBlockType1 ::= SEQUENCE {
cellAccessRelatedInfo SEQUENCE {
plmn-IdentityList PLMN-IdentityList,
trackingAreaCode TrackingAreaCode,
cellIdentity CellIdentity,
cellBarred ENUMERATED {barred, notBarred},
intraFreqReselection ENUMERATED {allowed, notAllowed},
csg-Indication BOOLEAN,
csg-Identity CSG-Identity OPTIONAL -- Need OR
},
cellSelectionInfo SEQUENCE {
q-RxLevMin Q-RxLevMin,
q-RxLevMinOffset INTEGER (1..8) OPTIONAL -- Need OP
},
p-Max P-Max OPTIONAL, -- Need OP
freqBandIndicator FreqBandIndicator,
schedulingInfoList SchedulingInfoList,
tdd-Config TDD-Config OPTIONAL, -- Cond TDD
si-WindowLength ENUMERATED {
ms1, ms2, ms5, ms10, ms15, ms20,
ms40},
systemInfoValueTag INTEGER (0..31),
nonCriticalExtension SystemInformationBlockType1-v890-IEs OPTIONAL
}

PLMN-IdentityInfo ::= SEQUENCE {
plmn-Identity PLMN-Identity,
cellReservedForOperatorUse ENUMERATED {reserved, notReserved}
}

SchedulingInfoList ::= SEQUENCE (SIZE (1..maxSI-Message)) OF SchedulingInfo
SchedulingInfo ::= SEQUENCE {
si-Periodicity ENUMERATED {
rf8, rf16, rf32, rf64, rf128, rf256, rf512},
sib-MappingInfo SIB-MappingInfo
}
SIB-MappingInfo ::= SEQUENCE (SIZE (0..maxSIB-1)) OF SIB-Type
SIB-Type ::= ENUMERATED {
sibType3, sibType4, sibType5, sibType6,
sibType7, sibType8, sibType9, sibType10,
sibType11, sibType12-v920, sibType13-v920, spare5,
spare4, spare3, spare2, spare1, ...}
CellSelectionInfo-v920 ::= SEQUENCE {
q-QualMin-r9 Q-QualMin-r9,
q-QualMinOffset-r9 INTEGER (1..8) OPTIONAL -- Need OP
}


SIB2-> System Information Block 2