Channel Configuration Configuration and Random Access
Overview
Over Ov ervi view ew - Ch Chan anne nels ls Upper Layers DL
UL
RLC B C C H
P C C H
C C C H
D T C H
D C C H
Logical channels
M C C H
M T C H
C C C H
D T C H
D C C H
MAC B C H
P C H
D L S C H
Transport channels
M C H
U L S C H
R A C H
PHY P B C H
P D S C H
P H I C H
P C F I C H
P D C C H
S y n c h
R S
P M C H
S R S
S R D
P R A C H
P U C C H
P U S C H
DL Physical Channels Allocation • RS/DTX: Reference Signal – Occupies at least 8 RE per RB(84 RE for normal CP ) • • • • •
•
throughout the whole system bandwidth PSS/SSS: Primary/Secondary Synchronisation Signal – Occupies the central 72 subcarriers across 2 symbols PBCH: Physical Broadcast Channel – Occupies the central 72 subcarriers across 4 symbols PCFICH: Physical Control Format Indication Channel – Occupies up to 16 RE per TTI PHICH: Physical HARQ Indication Channel – Occupies Occupies 12 12 RE, RE, and and Tx during during 1st symbol of each TTI or altern alternativ ativ during during symbols symbols 1 to 3 of each each TTI PDCCH: Physical Downlink Control Channel – Occupies the REs not used by PCFICH P CFICH and PHICH and Reference Signals within the first 1, 2 or 3 symbols of each TTI PDSCH: Physical Downlink Shared Channel – Is allocated the RE not used by signals or other
RB
UL Physical Physical Channels and Reference Signals PUSCH:: Physical Uplink Shared Channel • PUSCH – Intended for user data (carries traffic for multiple UEs) and control data – If control data is to be sent when traffic data is being transmitted, UE multiplexes both streams together
CCCH
DCCH
DTCH
Logical
• PUCCH: Physical Uplink Control Channel – Carries Carries H-ARQ Ack/Nack indications, indications, uplink uplink scheduling request, request, CQIs and
RLC
MIMO feedback
– Only control information is sent. The UE uses Resources Element at the edges of the channel
Transport
RACH
• PRACH: Physical Random Access Channel – SIB2 indicates the resource elements for PRACH use – System Information Information contains a list of allowed allowed preambles (64 per cell) and the
UL-SCH
required length of the preamble.
• DRS: Demodulation Reference Signal – For uplink demodulation and channel estimate • SRS: Sounding Reference Signal (not included in RL30) – For uplink channel aware scheduling
MAC
PHYS. PRACH
PUSCH
PUCCH
Overv Ove rview iew – Co Cont ntro roll In Info form rmati ation on CQI, PMI, RI, ACK/NACK
CQI, PMI, RI, ACK/NACK SR
eNode B CQI: Channel Quality Indicator PMI: Precoding Matrix Indicator DL control configuration 1x per cell
RI: Rank Indicator SR: Scheduling Request
RNTI DL scheduling UL Grant UL Power Control n x per cell HARQ Info
ACK: Acknowledgement NACK: Negative Acknowledgement RNTI: Radio Network Temporary Indicator HARQ: Hybrid Automatic Retransmission reQuest
Gene Ge neri ric c - Ba Band ndwi widt dth h • Channel bandwidth: Bandwidths ranging from 1.4 MHz to 20 MHz • Data subcarriers: They vary with the bandwidth – 72 for 1.4MHz to 1200 for 20MHz FDD Carrier Bandwidth [MHz]
Number of PRB
1.4
6
3
15
5
25
10
50
15
75
20
100
ulChBw / dlChBw Defines the UL and DL bandwidth and the number of available Physical Resource Blocks
Nokia MO
Parameter
Huawei MO
Parameter
Ericssons MO
Parameter
Generic Gen eric - Car Carrier rier Freq Frequen uency cy and Bandwi Bandwidth dth (FDD) (FDD) ...
100 kHz
...
FDL = FDL_low + 0.1(NDL – NOffs-DL)
EARFCN
Bandwidth
N UL : earfcnUL
UL: ulChBw
N DL : earfcnDL
DL: dlChBw
FUL = FUL_low + 0.1(NUL – NOffs-UL) earfcnUL/ earfcnDL Absolute Radio Frequency Channel Number LNCEL; 0...65535; 1; Note: Supported bands RL30: Band 1, 3, 4, 5, 6, 7, 9, 10,18, 19, 20, 24
earfcnUL = earfcnDL + 18000
Nokia MO
Parameter
LNCEL earfcnUL
Huawei MO MO
Cell
Parameter UlEarfcn
Ericssons MO
Parameter
EUtranCellFDD earfcnul
EUTRA Channel Numbers FDL = FDL_low + 0.1(NDL – NOffs-DL) FUL = FUL_low + 0.1(NUL – NOffs-UL)
Example TSEL has band3 with eARFCN DL= 1875 F DL = 1805 MHz + 0.1 (1875 – 1200) MHz = 1805 MHz + 0.1 (675) MHz = 1872.5 MHz EARFCN UL = EARFCN DL + 18000 = 19875 F UL = 1710 MHz + 0.1 (19875 (19875 – 19200) MHz
Example (band 12) F UL = 708 708 MHz MHz = 698 698 MHz MHz + 0.1 0.1 (231 (23100 00 – 230 23000 00)) MHz
= 1710 MHz + 0.1 (675) MHz = 1777.5 MHz
Generic Gen eric - Phy Physica sicall Laye Layerr Cell Cell Id • Physical Layer Cell Identity is used to differentiate neighbor cells • It consists of the two parts; Physical layer Cell Identity Group and Physical layer Identity • Physical Layer Cell Identity = 3 x Physical layer Cell Identity Group + Physical layer Identity • Decoded during synchronization synchronization using primary and secondary sync signal • s a result result of cell cell search the UE should ac"uire# ac"uire#
– – – –
PH$ cell %D &'ms and (ms timin) CP len)th Du*le+ mode ,-DD.FDD/
Strongest Signal
Cell ID Group 0 (3 L1 id’s)
phyCellId: 168 Cell ID groups
Physical Cell Id LNCEL; 0..503; 1; (Range; Step; Default)
Cell ID Group i (3 L1 id’s)
Primary Synchronization Signal
L1 id, id, slot slot (0/1 (0/10) 0)
Secondary Synchronisation Signal Group 167
Nokia
MO Parameter MO LNCEL *h0Cell%d Ce Cell
Huawei Parameter Ph0Cell%d
MO
Ericssons Parameter *h0sicalLa0erCell%d1rou* 2 3 4 *h0sicalLa0er5u6Cell%d
Phy L Cell ID Physical Layer Cell ID, Frame Alignment
Generic Gen eric – Time Stru Structu cture re and and CP len length gth • Subframe length is 1 ms for all bandwidths • Slot length is 0.5 ms – 1 Subframe= 2 slots • Slot carries 7 symbols with normal cyclic prefix pr efix or 6 symbols with extended prefix – CP length depends on the symbol position within the slot: ▪ Normal CP: symbol 0 in each slot has CP= 160 x Ts (5.21 μs and remaining symbols CP= 144 x Ts ( 4.7 μs) ▪ Extended CP: CP length for all symbols in the slot is 512 x Ts ( 16.67µs) Short cyclic prefix:
Ts: ‘sampling time’ of the overall channel. Basic Time Unit. Ts =
5.21 µs Long cyclic prefix: = Data
=
16.67 µs
1 sec
Subcarrier spacing X max FFT size 1 sec 15kHz X 2048
Copy
= 32.5nsec
DL Channels and Signals
DL - Cha Channe nnels ls and and Signa Signals ls Overvi Overview ew Upper Layers
RLC B C C H
B C H
P C C H
P C H
C C C H
D C C H
D L - S C H
D T C H
M C C H
M T C H
MAC M C H
H I
C F I
D C I
P H I C H
P C F I C H
P D C C H
PHY P B C H
P D S C H
P M C H
Air interface
S y n c h
R S
Synch Sy nch Sign Signals als – Time and Fre Freque quency ncy Slot id: 0 1 2 . .
..10..
..19 0 1
DTX Secondary Synchronisation Synchronisation Signal (SSS) Primary Synchronisation Signal (PSS)
180 kHz
PSS Primary Synchronisation Signal
Time slot (0.5 ms) syncronization • PSS placed strategically at the beginning and middle of frame • Estimation is vendor specific (matched filtering) • Frame ambiguity of 0.5 ms
Find physical layer cell ID • 1 out of 3 sequences sent on PSS • 1 to 1 mapping with the physical physical cell ID (table specified by 3GPP*) • The cell ID group not known yet
UE eNodeB
SSS Secondary Synchronisation Signal
Frame (10 ms) synchronization • 2 different sequences depending on the cell group are sent: SSS0 and SSS1 • By observing the combination of pairs SSS0 and SSS1 the UE can identify either the begining or the middle of the frame • Example: the sequence SSS0-PSS is indicating the begining of the frame, SSS1-PSS the middle of the frame
Find physical layer cell ID group • Sequences SSS0 and SSS1 are mapped with the cell id group 1..168 (table specified by 3GPP*) • The combination of SSS0 and SSS1 is giving the cell ID group
Sample PSS & SSS Decoding Result (QXDM) (Q XDM)
P55 7alue # '8 & or 9
Cell %D decoded
555 on Pre and
Reference Signals • Common Reference Signals (CRS): – Cell-specific – FDM/TDMuxed – Defined per antenna port – F-density 6 sub-carriers (or 3 sub-carriers if staggered structure is considered) – BW invariant mapping to REs – Used for: ▪ Channel estimation (in case of CRS-based transmission with known/signaled precoding) ▪ Mobility measurements ▪ Auxiliary UE functions like: • Time tracking • Frequency tracking • Cell ID verification • CP length verification *Staggered structure with multiple antenna ports (see next slide)
How Many Reference Signals? (1) y c n e u q e r F
First slot
Second slot
0 1 2 3 4 5 6 0 1 2 3 4 5 6 In Frequency: 1 reference symbol to every 6th subcarrier In one RB (resource block = 12 subcarriers): every 3rd subcarrier Exact position dependent on cell ID
Reference signal
*Normal CP (cyclic prefix) assumed Time In Time is fixed: 2 reference symbols per Time slot (TS 0 & TS 4) 3GPP TS 36.211 V8.6.0 (2009-03) (2009-03 )
Different Reference Signals Frequency Shift y c n e u q e r F
Shift = 0
Shift = 1
Shift = 5
Time
Reference signal
Cell-specific Reference Signals in Case of Multi-Antenna Transmission
Antenna port 0
Reference signal
Antenna port 1
Unused symbol
Incremental Time-Frequency Structure of Cell-specific Reference Signal t r o p a n n e t n a e n O
R0
R0
R0
R0
R0
R0
R0 l
R0
0
=
l
=
6 l
=
0
l=0 ……...... 6, 0 ………..
l
=
6
6
Resource Element (RE) k, l
Resource element (k,l )
s t r o p a n n e t n a o w T
R0
R0
R0
R0
R0 =
l
=
6
l
=
0
R0
l
=
0
=
6 l
=
R1
l
=
6
l
=
0
Antenna port 0
6
l
=
0
R3
R2
R1
l
=
6 l
=
R3
R2
R1
R1 =
6
6
R1
R1
l
=
R2
R1
0
l
R1
R1
R0
l
Reference symbols symbols (RS) on this antenna port
Reference symbols on this antenna port
l=0 ……...... 6, 0 ………..
R0
R0
0
6
6
R0
R0
=
=
R0
R0
l
l
Not used for transmission on this antenna port (DTX) (DT X)
Not used for transmission on this antenna port
R1
R1
l=0 ……...... 6, 0 ………..
s t r o p a n n e t n a r u o F
R1
R1
R0
0
R1
R1
R0
l
R1
R0
0
Antenna port 1
R3
R2
l
=
6
l
=
0
R3
l
=
6 l
=
0
Antenna port 2
l
=
6
l
=
0
l
=
6 l
=
0
Antenna port 3
l
=
6
Huawei Hua wei - Ref Referen erence ce Signa Signals ls Power Power Sett Setting ing • Cell Reference Signal Signal power value can be tune with parameter PDSCHCf PDSCHCfg.Ref g.Reference erenceSignal SignalPwr Pwr for Huawei. • Reference Reference Signal Signal power for for Nokia and and Ericssons Ericssons EUTRAN EUTRAN calculated calculated from from Total Total Power Power and CRSGain CRSGain Parameter
Parameter C:5 C:5 Power ower
Huawei ;PD5 ;PD5CH CHCf Cf)< )< :eference5i)nalPwr
Value
Nokia
Value
&=>9 dBm for N.> ? 9' watt C:5 *ower @3' ,9' watt/ calculated from &''' ,' dB/ ;LNCEL< *Ma+ and ;LNCEL< dl:sBoost
Ericssons N.>
Value
ZTE
Value
? @''''
;EUtranCellFDD< cell:eference5i)nalPower
&9 dBm
C:5 *ower calculated from ;5ectorE"ui*mentFunction< 3'' ,3 dB/ confi)uredOut*utPower nd ;EUtranCellFDD< crs1ain
PBCH Design Criteria Detectable without the knowledge of system Bandwidth → mapped to the central 72 subcarriers over 4 symbols during second slot of each frame
→ →
Low system overhead & good coverage • Send minimum information only the MIB (Master Information Block) • SIBs (System Information Blocks) are sent on PDSCH →
MIB (Master Information Block) content: – DL system Bandwidth – PHICH configuration (PHICH group number) – System frame number SFN
UE eNodeB
Physical Broadcast Channel • PBCH carriers essential s0stem information like# DL BW confi)uration – DL PH%CH confi)uration – PH%CH 50stem Frame Num6er ,= M5B 6its/ – 50stem • PBCH ena6les 6lind detection of# DL antenna confi)uration A&-8 9-8 @- 7ia C:C maskin)2 – DL – @' ms timin) ,9 L5B 6its of 5FN/ 7ia @'ms scram6lin)
-he M%B is a 9@ 6it information information # • 3 6its for s0stem s0stem 6andwidth • 3 6its for PH%CH information8 information8 • & 6it to indicate normal or e+tended e+tended PH%CH • 9 6it to indicate the PH%CH N) 7alue 7alue • = 6its for s0stem s0stem frame num6er • &' 6its are are reser7ed for future use
* for decoding the CRC (Cyclic Redundancy Check) each MIB is masked with a codeword representing the
Physical Layer Downlink DL-Physical DL-Physi cal Data & Control Channels
PBCH
'ne ()B "information its * s#are its * CRC$
Code and rate!matching "re#etition$ to numer of its availale on PBCH in %& ms
Segmentation into four e0ual sized individually self!decodale units
%& ms transmission time interval of PBCH
h t d i d n a d e s ,
s B R +
'ne radio frame
PBCH B R .
Synchronization signals Reserved for reference singals Remark: PBCH does not use locks reserved for reference signals
PBCH Mapping Slot 0 Slot 1 y c n e u q e r F
SSS PSS Reference signals Unused RE PBCH
z H M ) h t 4 . i 1 d = w d s n r a e i B r r a E c T b L u s m 2 u 7 i m – i n s m B ( R 6
Time
PBCH Repetition Pattern
one radio frame = 10 ms
s r e i r r a c b u s 2 7
Repetition Pattern of PBCH = 40 ms
Cell Search 1. PSS Primary Synchronisation Signal (Time-slot & Frequency synchronisation + Physical cell id (0,1,2) ) 2. SSS Secondary Synchronisation Signal (Frame synchronisation + Physical Cell id group (1..168) ) 3. DL Reference Signals (Channel estimation & measurements)
eNodeB
4. PBCH – Phy Physical sical Broadcast Broadcast Chann Channel el (MIB – DL system system bandwidth, bandwidth, PHICH PHICH configuration)
UE
Physical Layer Downlink DL-Physical DL-Physi cal Data & Control Channels
PCFICH • General – Physical Control Format Indicator Channel (PCFICH) carries the CFI (Control Format Indicator) ▪
(Indicates the number of OFDM symbols used for transmission of control channel information in each subframe)
– Carriers dedicated to MBSFN have no physical control channel and therefore no PCFICH – 4 code words defined ▪
3 CFIs used and one reserved for future f uture use (see table below) CFI
CFI codeword
1
<0,1,1,0,1,1,0,1,1,0,1,1,0,1,1,0,1,1,0,1,1,0,1,1,0,1,1,0,1,1,0,1>
2
<1,0,1,1,0,1,1,0,1,1,0,1,1,0,1,1,0,1,1,0,1,1,0,1,1,0,1,1,0,1,1,0>
3
<1,1,0,1,1,0,1,1,0,1,1,0,1,1,0,1,1,0,1,1,0,1,1,0,1,1,0,1,1,0,1,1,>
4 (reserved)
<0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,>
• Transmitted – – – –
In the first OFDM symbol in a subframe The 32 bits of the CFI are mapped to 16 REs using QPSK modulation PCFICH is transmitted on the same antenna ports as the PBCH P BCH (1Tx, SFBC, SFBC-FSTD) Cell specific offset is added Cell specific scrambling
PCFICH information is 2 bits, with coding rate = 1/16 --> then 2 bit will be transmitted on 2 * 16 = 32 bit = 16 RE (QPSK modulation) = 4 REG
PCFICH Mapping to Resource Elements • • • •
-he ma**in) is done in in terms of "uadru*lets of modulation s0m6ols for each antenna *ort "uadru*let is defined as d,@i/8 d,@i/8 d,@i4&/8 d,@i49/8 d,@i49/8 d,@i43/ :eference s0m6ols :Es are alwa0s reser7ed for at least 9-+ antennas -he four "uadru*lets shall 6e ma**ed to four resource element )rou*s ,:E1/ ,:E1/ ,aka mini?CCE/ mini?CCE/ in the first OFDM OFDM s0m6ol
– E+am*le# 9 su6carriers case ,&>@ MH/# frequency
Ant 0
d0
d1
Ant 1
-d1 * d0*
frequency
Resource element group
d0
2
cell DL ⋅ N ID mod2N RB
d2
Ant 1 Ant 2 DL
N RB 2
⋅
RB
N sc
2
-d3 * d2*
d1
Distance between mini-CCEs RB k = N sc
d3
frequency
Ant 0 Starting position depends on cell id
d2
Ant 3
d3
-d1 * d0* -d3 * d2*
Sample PCFICH Decoding Result (QXDM)
5u6 Frame
CF% 7alue8
Nokia MO
PHICH
Parameter
Huawei MO
Parameter
LNCEL
*h *hichDur
PH%CHCf)
PhichDurat ration
LNCEL
*hi *hich:es
PH%CHCf)
Phich:esource
• For H:G ACK/NACK si)nalin) the PH%CH is de*lo0ed> • PH%CH is defined defined 60 its PH%CH )rou* num6er and an ortho)onal ortho)onal se"uence num6er within the )rou*>
• PH%CH modulation is BPSK> **l0in) I/Q separation and an S!" 0ields # ort$o%onal se&uences for normal CP> 5F 9 is in use in case of e+tended CP8 hence there are @ ortho)onal se"uences> %8e> in total there ma0 6e = >> 99@ PH%CHs in one su6frame>
• E+am*le# BW&( su6carriers su6carriers normal normal CP8 N)&.I8 & PH%CH )rou*> &9 s0m6ols are to 6e transmitted>
• N:B # DL BW . :Bs • N) &.I8 &.98 &.98 2&82 9> 9> settin)# p$ic$'es DL
*Necessary with semi-persistent scheduling
group PHICH
N
DL N g ( N RB 8) = DL 2 ⋅ N g ( N RB 8) Number of RBs
Sequence Index
Orthogonal sequence Normal CP
Extended CP
0
+1 +1 +1 +1
+1 +1
1
+1 -1 +1 -1
+1 -1
2
+1 +1 -1 -1
+j +j
3
+1 -1 -1 +1
+j -j
4
+j +j +j +j
5
+j -j +j -j
6
+j +j -j -j
7
+j -j -j +j
e.g. 20 MHz phichRes
phichRes
1/6
1/2
1
2
#PHICH groups
#PHICH groups
3
7
13
25
LNCEL; 1/6; ½; 1; 2; 1/6
# scheduled UE
24
56
10 4
200
for normal cyclic prefix for extended cyclic prefix
each PHICH group for normal CP has 8 orthogonal sequence that means can support 8 user 3 PHICH groups = 3 * 8 user = 24 user each each PHI PHICH CH grou group p have have 12 symbol symbols s = 3 REG
PHICH Association and Resource Indication PhichDur PHICH PHICH on symb. symb. 1 / 1- 3 LNCEL; Normal (0), Extended (1) ; 1; Normal(0)
• PHICH duration: duration: normal subfram subframes es (indicated (indicated via via PBCH) PBCH) – 1 or 3 OFDM symbols in normal
• PHICH linked to UL PRB grouping - spreads out the PHICH of adjacent adjacent PRBs to different different PHICH groups groups • Scattered grouping • When DM-RS Cyclic Shift index is configured in UL grant, use DM-RS CS index as modifier to adjust PHICH allocation – Avoid PHICH collision e.g. in case of UL MU-MIMO – Balance power among PHICH groups • PHICH indexing: – Both index of the group and within the group depend on first UL PRB index and UL DM-RS Cyclic Shift
PDCCH Overview • -he PDCCH carries t$e () * +) sc$e,ulin% assi%nments • PDCCH is transmitted on an a))re)ation of one &8 98 @ or = control channel elements ,CCE/ ,CCE/>> CCE consists of -. 'Es 0 'E12
• -he a))re)ations of CCEs ha7e a tree structure8 where an a))re)ation consistin) of n CCEs starts on *osition *osition ,i mod n/8 where i is the CCE num6er
• Further restrictions on the a))re)ations are defined with a Hashin) function
pdcchAggDefUE PDCCH LA UE default aggregation; used, when enableAmcPd enableAmcPdcch cch disabled disabled or no valid CQI exists LNCEL; LNCEL; 1(0), 1(0), 2 (1), 4 (2), (2), 8 (3); -; 4 (2)
PDCCH format 0 1 2 3
Number of CCEs 1 2 4 8
Number of resourceelement groups 9 18 36 72
Number of PDCCH bits 72 1 44 2 88 5 76
DL - L1/ L1/L2 L2 contr control ol info: info: PDCC PDCCH H Resourc Resources es • • • • • •
The MaximumNumberOfOFDMSymbolsForPDCCH MaximumNumberOfOFDMSymbolsForPDCCH parameter defines defines how many many OFDM symbols symbols can be used. eNB selects the actual actual value for each TTI, which which is signaled to UE in PCFICH. PCFICH. Range: 1, 2, 3 (BW > 1.4 MHz); maxNrSymPdcch Range: 2, 3, 4 (BW = 1.4 MHz) LNCEL; 1..3; 1; 3 setting: maxNrSymPdcch Example shows shows dynamic dynamic case for MaximumNumberOfOFDMSymbo MaximumNumberOfOFDMSymbolsForPDCCH=3 lsForPDCCH=3 (yellow) (yellow)
Nokia MO
Parameter
Huawei MO
Parameter
Ericssons MO
Parameter
LNCE LNCELL ma+N ma+Nr5 r50m 0mPd Pdcc cch h Cell CellPd Pdcc cch hl) l)o o %nit %nitPd Pdcch cch50 50mN mNum um
EUtra EUtranC nCel ellF lFDD DD nrO nrOf5 f50m 0m6o 6ols lsPd Pdcc cch h
LNCE LNCELL actLd actLdPd Pdcc cch h
EUtr EUtran anCe Cell llFD FDD D *dcc *dcchC hCfi fiMo Mode de
Cell CellPd Pdcc cch hl) l)o o Pdcc Pdcch5 h50m 0mNu Num5 m5wi witc tch h
Downlink Control Information (DCI) • DC% trans*orts control control information for one MC %D8 which is im*licitl0 im*licitl0 si)naled in the C:C> – Format ' ▪
Used for definin) the transmission of P(SCH assi%nments
– Format & ▪
Used for definin) the transmission of P+SCH assi%nments for sin%le co,ewor, ,5CW/ o*eration
– Format & ▪
Com*act form for the transmission of PD5CH assi)nments for 5CW o*eration2> Has same sie as format '
– Format &B ▪
Com*act form like & 6ut su**orts close,3loop rank 4 preco,in%
– Format &C ▪
5i)nalin) for PCH5 'ACH * BCCH on DL 5CH ,aka d0namic BCCH/
– Format &D ▪
Like DC% & 6ut su**orts *ower offsets for DL 6(36I67 and -PM%
– Format 9 ▪ Used for definin) the transmission of DL?5CH assi)nments for Close,3)oop 6I67 o*eration – Format 9 ▪ Used for definin) the transmission of DL?5CH assi)nments for 7pen3)oop 6I67 o*eration – Format 3 ▪ Used for TPC comman,s for PUCCH and PU5CH with 839it power a,:ustments > Has same sie as format ' – Format 3 ▪ Used for TPC comman,s for PUCCH and PU5CH with 439it power a,:ustments > Has same sie as format '
DCI Format 1 (all): PDSCH resource assignment when no Spatial Multiplexing used
DCI formats 2 & 2A: provide PDSCH assignments for closed loop or open loop
spatial multiplexing
Sample PDCCH decoding Result (QXDM)
))re)ation Le7el
DC% format
5tart CCE
Sample PDCCH decoding Result (QXDM)
Physical Layer Downlink Summary DL-Physical Data & Control Channel
SSS
y c n e u q e r F
PSS PBCH PCFICH PHICH PDCCH Reference signals PDSCH UE1 PDSCH UE2
Time
Exercise: PDCCH Resources Task; • Consider cell confi)uration# BW(' P:B8 9 antenna *orts8 normal CP • Ma+imumNum6erOfOFDM50m6olsForPDCCH9 • N) &.I Calculate the num6er of a7aila6le PDCCHs> ssume for fre"uenc0 of occurancies of different a))re)ation le7els ,L/ L@ is 9 times the fre"uenc0 of L= L9 is 9 times the fre"uenc0 of L@ L& is &.9 times the fre"uenc0 of L9
Solution: PDCCH Resources Task; • Consider cell confi)uration# BW(' P:B8 9 antenna *orts8 normal CP • Ma+imumNum6erOfOFDM50m6olsForPDCCH9 • N) &.I Calculate the ma+ num6er of PDCCHs>
Solution; ? &st s0m6ol 0ields 8 'E1s *er P:B + (' P:B &'' :E1s ,6ecause , 6ecause of the reference si)nals/ si)nals / ? 9nd 0ields 3 + (' &(' :E1s> -otal# 9(' :E1s> ,no ,no reference si)nals / :E1s for PCF%CH8 9+3I for PH%CH 9@' :E1s remain for PDCCH ? @ :E1s ? 8"< di7 9I CCEs are a7aila6le ? For & distri6ution distri6ution &+L= 4 9+L@ 9+L@ 4 @+L949+L& @+L949+L& ssum*tion# a))re)ation le7el = &+
? ? ? ?
))re)ation le7el = &+ = CCEs ))re)ation le7el @ 9+ 9 2 @ CCEs = CCEs ))re)ation le7el 9 9 2 ,9+/ @+ @+ @ 2 9 CCEs = CCEs ))re)ation le7el & '>( 2 @+ 9+ 9 2 & CCE 9 CCEs
-otal PDCCH & L= 4 9 L@ 4 @ L9 4 9 L & & 4 9 4 @ 4 9 PDCCH
ULL Channels U Channels and Signals
UL Channel Mapping Upper Layers
RLC H C C C
H C T D
H C C D
MAC H C S L U
U C I
H C A R
PHY H C S U P
H C C U P
H C A R P
Air interface
D R S
S R S
UE Channel state information (CSI) feedback types in LTE purpose o= CSI =ee,9ack is to pro>i,e t$e eNo,eB in=ormation a9out +) • T$e purpose c$annel state to $elp in t$e sc$e,ulin% ,ecision?
• Com*ared to the WCDM.H5P8 the main new feature in the channel feed6ack is the fre"uenc0 selecti7it0 of the re*ort
• C5% is measured measured 60 the UE and si)naled to the eNodeB eNodeB usin) PUCCH or or PU5CH
(1) eNodeB transmission
• Channel state information information in L-E can 6e di7ided into three three cate)ories# CQI ? Channel Gualit0 %ndicator 'I ? :ank %ndicator P6I ? Precodin) Matri+ %ndicator
• %n )eneral the C5% re*orted re*orted 60 the UE is Just a recommendation recommendation -he eNodeB does not need to follow it
• -he corres*ondin) corres*ondin) *rocedure for *ro7idin) *ro7idin) UL channel state information is called Channel 5oundin)K it is done usin) the 5oundin) :eference 50m6ols8 5:5 ,not considered in this *resentation/
(2) UE CSI measurement (3) UE feedback
Channel Quality Indicator (CQI) CQI in index
• -he most im*ortant *art of channel feed6ack is the CG% • -he CG% is defined as a ta6le containin) containin) &I entries with modulation modulation and codin) schemes ,MC5s/
• -he UE shall re*ort 6ack 6ack the hi)hest CG% inde+ corres*ondin) corres*ondin) to the MC5 for which the trans*ort 6lock B)E' s$all not e@cee, 4<
UE reports highest MCS that it can decode with a TB Error rate < 10% ⇒
taking into account UE’s receiver characteristic
modulatio n
0
coding rate x 1024
efficiency
out of range
1
QPSK
78
0 .1 5 2 3
2
QPSK
12 0
0.2344
3
QPSK
19 3
0.3770
4
QPSK
30 8
0.6016
5
QPSK
44 9
0.8770
6
QPSK
60 2
1.1758
7
16QAM
378
1 .4 7 6 6
8
16QAM
490
1 .9 1 4 1
9
16QAM
616
2 .4 0 6 3
10
64QAM
4 66
2 .7 3 0 5
11
64QAM
5 67
3 .3 2 2 3
12
64QAM
6 66
3 .9 0 2 3
13
64QAM
7 72
4 .5 2 3 4
14
64QAM
8 73
5 .1 1 5 2
15
64QAM
9 48
5 .5 5 4 7
* Efficiency is defined as number of bits per resource elements
Rank Indicator (RI)
• 'ank In,icator is onl0 rele7ant when the UE is o*eratin) in M%MO modes with spatial multiple@in% For sin)le antenna o*eration or - di7ersit0 it is not used – For
• :% is the UEs recommendation for the num9er o= laers to 6e used in s*atial multi*le+in) • -he :% can ha7e 7alues A& or 9 with 9?60?9 antenna confi)uration and A&8 98 38 or @ with @?60?60 antenna confi)uration
• -he :% is alwa0s associated to one or more CG% re*orts riEnable Determines whether RI reporting is enabled (true) or not (false) LNCEL; true (1); false(0); false (0)
Nokia MO LNCEL
Parameter ri riEna6le
Huawei MO
CellDlschl)o
Parameter Dl:ankDetect5witch
Precoding Matrix Indicator (PMI) • PM% *ro7ides information a6out the *referred Preco,in% 6atri@ • ust like :%8 also PM% is rele7ant to M%MO o*eration onl0 – M%MO o*eration with PM% feed6ack is called Closed Loop MIMO
* PMI to support CL Spatial Mux MIMO
Example: codebook for 2 TX antennas
Periodic and Aperiodic Reporting • -he channel feed6ack re*ortin) in L-E is di7ided into two main cate)ories# Periodic and *eriodic cqiPerNp CQI periodicity LNCEL; 2; 5; 10; 20; 20 ms
CQIAperEnable enabling / disabling aperiodic CQI /RI/PMI reporting on PUSCH. LNCEL; false/true; true
Periodic reporting
Aperiodic Reporting
• The baseline mode for CQI/PMI/RI
• Aperiodic reports are explicitly triggered by the eNodeB using a specific bit in the PDCCH UL grant
transmission is periodic reporting on PUCCH • If the UE is scheduled to send UL data in the subframe where it should transmit periodic CQI/PMI/RI, the periodic report is moved to PUSCH and multiplexed with data • The eNodeB configures the periodicity parameters • The size of a single report is limited up to about 11 bits depending on the reporting mode • Limited amount of frequency information
• Aperiodic report can be either piggybacked with data or sent alone on PUSCH • Possibility for large and detailed reports (up to more than 60 bits) The two modes can also be used to complement each other: - The UE can be e.g. configured configured to send send Aperiodic reports only when it is scheduled, while periodic reports can provide coarse channel information on a regular basis
Categorization of CQI/PMI/rank reporting options cqiAperMode Aperiodic CQI feedback mode
The maximum number of feedback bits for each option Assuming 20 MHz BW and 4*4 CL MIMO is listed liste d excluding RI - With Periodic Periodic report reporting ing RI is sent sent in separate subframes with potentially larger periodicity - In Aperiodic Aperiodic reporti reporting ng The RI RI is separately coded with each CQI/PMI report
LNCEL; LNCEL; FBT1(0) FBT1(0) – familly modes modes 2-x, 2-x, FBT2(1)FBT2(1)- familiy modes 3-x (x defined by MIMO algorithm internal in eNodeB); FBT2 (1) Single or Multi-PMI = closed loop MIMO with PMI feedback No PMI = Single antenna, TxDiv or OL MIMO
LTE CQI reporting family tree
Aperiodic
Periodic
Wideband
No PMI
Single PMI
Frequency selective
No PMI
Single PMI
Mode 1-0
Mode 1-1
Mode 2-0
Mode 2-1
4 bits
11 bits
6 bits
11 bits
Single CQI
Best-M Average
Full Feedback
Multi PMI
No PMI
Multi-PMI
No PMI
Single PMI
1-2
Mode 2-0
Mode 2-2
Mode 3-0
Mode 3-1
60 bits
24 bits
38 bits
30 bits
64 bits
*See TS 36.213
CQI Aperiodic Reporting on PUSCH (1/2) • Com*ared to the WCDM.H5P8 the main new feature in the channel feed6ack is the fre"uenc0 selecti7it0 of the re*ort ,FDP5/ – -his is an ena6ler for the Fre"uenc0 Domain *acket 5chedulin) ,FDP5/
• 5ince *ro7idin) a full @?6it CG% for all the P:Bs would mean e+cessi7e UL si)nalin) o7erhead8 some feed6ack com*ression schemes are used 6asis • %n order to reduce feed6ack8 the CG% is re*orted *er subband 6asis – -he sie of the su66ands 7aries de*endin) on the re*ortin) mode and s0stem 6andwidth • -he main com*ression methods are# Wide6and feed6ack – Wide6and called UE selected su66and feed6ack – Best?M a7era)e also called called Hi)her La0er Confi)ured su66and feed6ack – Full Feed6ack also called • dditionall08 Delta com*ression can 6e used si)naled as a 3?6it 3?6it delta relati7e to the CG% of the CG% of – E>)> in M%MO case the CG% for the 9nd Code Word can 6e si)naled the &st CW
CQI Aperiodic Reporting on PUSCH (2/2) • Wide6and feed6ack 7alue is fed 6ack for the whole s0stem 6and – Onl0 a sin)le CG% 7alue – Cannot 6e utilied in FDP5 ,Fre"uenc0 Domain Packet 5cheduler/ • Best?M a7era)e also called UE selected su6?6and feed6ack For the M 6est su6?6and an average CG% 7alue is re*orted – For M = 3 best Subbands are selected and an average CQI value is i s reported
An example of Best-M Average reporting with 3 MHz BW (15 RBs means that the subband size is 2 RBs and the best 3 subbands are reported)
Subband index PRB index
BW / RB
Subband size (RBs)
# best Subbands M
6-7
NA
NA
8-10
2
1
11-26
2
3
27-63
3
5
64-110
4
6
Channel SINR
1 1
2 2
3
3 4
5
4 6
7
8
5 9 10
6 11 12
7 13 14
8 15
• Full Feed6ack also called Hi)her La0er Confi)ured su6?6and feed6ack
CQI Rep CQI Repor orti ting ng Co Conf nfig ig – Sa Samp mple le me mess ssag age e RRCConnectionSetup
TS36.213 (Tables (Tables 7.2.2-1A 7.2 .2-1A and 7.2.2-1B).
CQI Periodic Reporting on PUCCH or PUSCH • Wide6and feed6ack or UE selected su6?6and • Period confi)ura6le cqiPerNp – 98 (8 &'8 &'8 9'8 @'8 @'8 =' ms CQI periodicity a*eriodic re*ortin) • Wide6and feed6ack similar to a*eriodic LNCEL; LNCEL; 2; 5; 10; 10; 20; 40; 80; 20 ms • UE selected su6?6and# – sin)le CG% CG% result *er re*ort – -he total num6er of su6?6ands is di7ided into fractions fractions called 6andwidth *arts – Onl0 the 6est su6?6and *er BW *art is re*orted re*orted – E+am*le# for 3 MH there are @ :Bs *er su6?6and so there are &(.@ @ su6?6ands> -hose @ su6?6ands are di7ided into 9 BW B W *arts which means that there are 9 su6?6ands *er BW *art>2
• Confi)ured 60 hi)her la0er la0er si)nalin) si)nalin) BW / RB
Subband Size k (RBs)
BW Parts (J) Nokia MO
6-7
NA
NA
LNCEL
8-10
4
1
LNCEL
11-26
4
2
27-63
6
3
Parameter c"iPerN* actUL1r*Ho*
Huawei MO
Parameter
C"ida*ti7eCf)
UserC"iPeriodCf)
C"id C"ida*t a*ti7eC i7eCf) f)
PucchP PucchPeri eriod odicC" icC"iO* iO*t5 t5wit witch ch
PU5CHCf)
1rou*Ho**in)Ena6led
PU5CHCf)
1rou*ssi)nPU5CH
LNCEL
deltaPucch5hift
PUCCHCf)
Delta5hift
LNCEL
*ucchnanC5
PU5CHCf)
C0clic5hift
Uplink Control Signaling: PUCCH vs. PUSCH
: Single carrier limitations : Simultaneous transmission of PUCCH and PUSCH is not allowed. Separate control resources for the cases with and without UL data are required
• PUCCH ,Ph0sical U*link Control Channel/ • PUSCH (Physical Uplink Shared Used when the UE is not sen,in% ,ata Channel) – Used simultaneousl – Used when the UE transmits also 5hared fre"uenc0 and time resource – 5hared data reser7ed e+clusi7el0 for the UEs transmittin) onl0 L&.L9 control si)nals O*timied for lar)e num6er of – O*timied simultaneous UEs with relati7el0 small num6er of control si)nalin) 6its *er UE ,&&&/ er0 hi)h multi*le+in) ca*acit08 – er0 s*ectral efficienc0 e>)> ▪ 4# (Es/'B transmittin) C.NC ,PUCCH Format &a.&6/ ▪ . (Es/'B transmittin) &&?6it CG% 4 9? 6it .N ,PUCCH Format 96/
– UE-specific resource that can be used for L1/L2 control signaling (based on scheduling decisions made by Node B) – Capable to transmit control signals with large range of supported control sizes (1… 64 bits) – TDM between control and data (multiplexing is made prior DFT)
*TDM = Time Domain Multiplexing
Zadoff-Chu Sequence • adoff?Chu se"uences are used as – UL demodulation and soundin) :eference 5i)nals – :andom ccess *ream6le se"uence – DL *rimar0 s0nchroniation s0nchroniati on si)nal
• C se"uence are CC ,Constant m*litude m*litude ero uto Correlation/ se"uence – Low cu6ic metric and flat fre"uenc0 res*onse
• -he elements of C se"uences are *oints from unit circle • %t is *ossi6le *ossi6le to create C se"uences of an0 len)th with with relati7el0 sim*le formulas de*endin) on se"uence len)th8 different num6er of 6ase.root se"uences can 6e formed – 5e"uence with *rime num6er of elements is o*timal – :oot se"uence can 6e considered as circular> Different Differe nt c0clic shift of a root se"uence can 6e o6tained 60 chan)in) the startin) element ▪
C0clic shift must 6e lar)er than time am6i)uit0 of recei7ed se"uence
UL Reference Signal Overview UL DM:5 allocation *er slot for normal c0clic *refi+ -0*e of UL :eference 5i)nals
• Demodulation :eference :eference 5i)nals ,DM :5/ – PU5CH.PUCCH data estimation
• 5oundin) :eference 5i)nals ,5:5/ – Mainl0 UL channel estimation UL
DM:5 is characteried 60 #
• 5e"uence ,adoff Chu codes/ • 5e"uence Len)th# e"ual to the Q of su6carriers use • 5e"uence )rou*# – 3' o*tions – Cell s*ecific *arameter
• C0clic 5hift# 5hift# UE and cell s*ecific *arameter
Group Hopping for UL Reference Signal
-his feature randomies the se"uence used to )enerate the
• Demodulation :eference 5i)nals for the PUCCH • Demodulation :eference 5i)nals for the PU5CH • 5oundin) :eference 5i)nals Hel*s to im*ro7e *erformance when the R PCI mod 30 S rule was not followed durin) PC% *lannin) *rocess cells • :educes risk of *otential issues caused 60 cross?talk 6etween nei)h6orin) cells UE are informed whether )rou* ho**in) is ena6led or disa6led usin) 5%B9 content
actULGrpHop Activation of uplink group hopping LNCEL; 0 (False); 1 (True); 0 False Nokia
Huawei
PUCCH, basics • PUCCH ,from sin)le?UE *ers*ecti7e/ Fre"uenc0 resource of one :B – Fre"uenc0 – -ime -ime resource of one su6?frame ,.N re*etition is also su**orted/
• 5lot 6ased fre"uenc0 ho**in) is alwa0s used %t *ro7ides the sufficient suffic ient de)ree of fre"uenc0 di7ersit0 – %t Ho**in ) takes *lace on the 6and ed)es8 s0mmetricall0 o7er the center – Ho**in) fre"uenc0
• Multi*le+in) 6etween UEs FDM 6tw :Bs – FDM CDM inside the :B – CDM
Resource block
system bandwidth
PUCCH
* FDM = Frequency Division Multiplexing CDM = Code Division Multiplexing A/N = ACK/NACK
slot
PUCCH, UE Multiple Access Within a RB deltaPucchShift • UEs are se*arated usin) of CDM ,within an :B/ delta cyclic shift for f or PUCCH formats 1/1a/1b LNCEL; 1..3; 1; 2 (i.e. 6 cyclic shifts) • -wo ortho)onal CDM techni"ues are a**lied on PUCCH shifts of CC2 se"uence – CDM usin) c0clic shifts with the ortho)onal co7er se"uence – CDM usin) 6lock?wise s*readin) with Nokia
• Multi*le+in) e+am*le# PUCCH Format &.&a.&6 ,e>)>8 .N/ *arallel resources – Both CDM techni"ues are in use ?T &= *arallel
MO
Parameter
LNCEL CEL
deltaPucch5hift
block-wise spreading
SF = 3 for Reference Signals and SF = 4 for ACK/NACK SF = Spreading Factor
Cyclic shift
SF=4 SF=3
RS
RS
slot
*CDM = Code Division Multiplexing
RS
CDM in CS domain
Orthogonal cover code 0 1 0 0 1 6 2 1 3 7 4 2 5 8 6 3 7 9 8 4 9 10 10 5 11 11
2 12 13 14 15 16 17
MO PUCCHCf)
Huawei Parameter Delta5hift
PUCCH Formats
• Format &.&a.&6 Len )th?&9 CC se"uence modulation 4 6lock?wise s*readin) ?T & s0m6ol ,& or 9 6its *er slot/ – Len)th?&9
• Format 9.9a.96 Len )th?&9 CC se"uence modulation , no 6lock?wise s*readin)/ ?T ( s0m6ols *er slot – Len)th?&9
PUCCH formats PUCCH Format 1 PUCCH Format 1a PUCCH Format 1b PUCCH Format 2 PUCCH Format 2a PUCCH Format 2b
Control type Scheduling request 1-bit ACK/NACK 2-bit ACK/NACK CQI CQI + 1-bit ACK/NACK CQI + 2-bit ACK/NACK
Number of Bits ON/OFF keying 1 2 20 21 22
Multiplexing Capacity (UE/RB) 36, *18 *18,, 12 36, *18 *18,, 12 36, *18 *18,, 12 12, *6, 4 12,* 12,* 6, 6, 4 12, *6 *6,, 4
Mapping of logical PUCCH resources into physical PUCCH resources • Periodic CQI is located at the outermost RBs – These resources are allocated explicitly via RRC
• SR and persistent A/N are next to Periodic CQI – These – These resources are allocated explicitly via RRC
• Dynamic A/N is located at the innermost PUCCH RBs – Allocated – Allocated implicitly based on PDCCH allocation m=1 m=3
m = 0 & 1 may contain formats 2/2a or 2b (e.g. CQI) -> fixed allocation m = 2 & 3 may contain formats 1/1a or 1b (e.g. ACK)
m =0 m =2
system bandwidth
PUCCH
-> dynamic allocation
m=2 m=0
m =3 m =1
PUCCH Dimensioning (1/2) • Scope: Dimensioning of the PUCCH region (how many RBs) to avoid excessive overheads • Necessary to calculate how many PUCCH resources (m) are needed for Formats1.x and Formats 2.x
PUCCH Dimensioning (2/2) • Total number of Resources required for PUCCH is the sum of the resources required for scheduling requests, for CQI and for Dynamic ACK/NACK: MaxPucchR MaxPuc chRes esourc ourceSi eSize ze = nCqiR nCqiRb b + roundu roundup p {[((m {[((max axNum NumOfC OfCce ce)) + n1Puc n1PucchA chAn n – puc pucchn chnanC anCS S*3/ deltaPucch delta PucchShift Shift ) * deltaPu deltaPucchSh cchShift] ift] / (3*12 (3*12)} )} + roundup roundup (pucc (pucchnanC hnanCS S / 8) deltaPucchShift nCqiRb reserved RBs per slot for PUCCH formats 2/2a/2b LNCEL; 1..98; 1; 2
pucchnanCS Number of cyclic shifts for PUCCH formats 1/1a/1b in the mixed region LNCEL; 0..7; 1; 0 (0 means no use of mixed formats )
n1PucchAn Offset to calculate ACK/NACK resources from PDCCH CCE LNCEL; 0..2047; 1; 36 Recommended special value: 10 to have a high UL Throughput. With that value only one PUCCH PRB is used for SR and dynamic ACK/NACK. ACK/NACK. That T hat means, the second PRB is for CQI
maxNumOfCce depends on dlChBw parameter: - if dlChBw is is 5MHz then maxNumOfC maxNumOfCce ce is 21
delta cyclic shift for f or PUCCH formats 1/1a/1b LNCEL; 1..3; 1; 2
Samp Sa mple le PUC PUCCH CH Tx Tx Re Repo port rt (QXD (QXDM) M)
PUCCH 5end on :B ' slot ' and :B @ slot &
Sounding Reference Signal UE scheduling & SRS Configuration The SRS configurations provide provide UEs by two SRS classes which are introduced by feature: SRS class … that assigns a multitude of resources for a limited number of UE’s that provides sufficient SRS resources for the proper scheduling of the UEs UE specific channel state information (CSI) is derived from: - PUSCH - sounding reference signals (SRS)
SRS Configuration • The operator can choose an SRS configuration from a given set of predefined configurations tailored for the usable PUSCH spectrum - srsConfiguration • The SRS resources which are selected for the UEs are assigned by means of the RRC Connection Reconfiguration and RRC Connection Reestablishment messages. enabled/disabled by • The usage of measurements from SRS in closed loop uplink power control can be enabled/disabled setting the parameter Include SRS measurements In CL power control (ulpcSrsEn ). ).
……
SRS Bandwidths Wideband SRS Transmission
Narrowband SRS Transmission
(Non Frequency hopping SRS )
(Frequency hopping SRS )
Subframe 1
Subframe 6 Subframe 1
Subframe 2
More
s B R 6 1
System bandwidths 40–60 RBs. SRS BW config.
SRS BW0
SRS BW1
SRS BW2
SRS BW3
0
48
24
12
4
1
48
16
8
4
2
40
20
4
4
3
36
12
4
4
4
32
16
8
4
5
24
4
4
4
6
20
4
4
4
7
16
4
4
4
wideband SRS bandwidth = 4 RBs � 3 = 12 RBs
Minimum Narow SRS bandwidth
Random Access
Overview Random access procedure is performed for the follo following wing events: •
Initial access from RRC_IDLE
•
RRC Connection Re-establishment procedure
•
Handover
•
DL data arrival during RRC_CONNECTED RRC_CONNECTED requiring random access procedure
•
UL data arrival during RRC_CONNECTED RRC_CONNECTED requiring random access procedure •
E.g. whe when n UL synchronisation synchronisation status is "non-synchronised "non-synchronised"" or there are no PUCCH resources for SR available
It takes two distinct forms: • Contention based (applicable to all five events); •
Non-contention Non-contention based (applicable to only handover and DL data arrival)
Normal DL/UL transmission can take place after the random access procedure In total there are 64 preambles per cell (pooled into 2 groups) Preambles are grouped to indicate the length of the needed resource. A number of preambles are reserved for contention-free access
Multiplexing of PRACH with PUSCH and PUCCH PRACH slot Duration( e.g. 1ms)
PUCCH h t d i w d n a B L U l a t o T
PRACH
PRACH
PRACH bandwidth (1.08MHz)
PUSCH PRACH slot period
PUCCH
Time
PRACH Subcarriers
• UE sends the preamble to the network on PRACH P RACH • PRACH occup occupies ies 6 RBs in a sub frame frame (or set set of consecutive consecutive subfram subframes) es) reserverd reserverd for sending sending random access preamble to the network • The The leng length th of TCP (Cyclic Prefix), TPRE (Peamble) and TGT (Guard Time) depends on the preamble form
• PRACH reserved reserved PRBs PRBs cannot cannot be u used sed by by PUSCH. PUSCH. i.e they are are out of scope scope for schedul scheduling ing for data transmission
PRACH Types PRACH PRA CH configuration index
( → see next slides)
parameter selects one of the 4 types Example timing for type 0:
DL timing (eNB) 1 ms 0.1 ms
0.8 ms
UE Tx CP
Preamble
GT eNB Rx
PRACH Types PRACH types: • Type 0: 1 ms duration • Type 1: 2 ms • Type 2: 2 ms • Type 3: 3 ms
Format type 0 & type 1 supported in RL30
PRACH Configuration Type, time and frequency resources are defined by: prachFreqOff
prachConfIndex PRACH configuration index:
LNCEL; 3..24;1; 3 Range is restricted to two different ranges: 3-8 and 19-24 (internal)
PRACH frequency offset:
First PRB available for PRACH in UL LNCEL; 0...94;1; 3
n RA PRB
=
n RA PRB offset
Max. value value is ulChBw( ulChBw(in in PRB) - 6
• PRACH can be placed either on lower or upper edge of the bandwidth • Therefore Therefore the possib possible le range for prachFr prachFreqOff eqOffset set is UL 0 ≤ n RA PRBoffset ≤ N RB − 6
.
• If PRACH area is placed at the lower border of UL frequency band then: • If PRACH area is placed at the lower border of UL frequency band then:
PRACH Configuration Parameter
Nokia Parameter MO MO Parameter P:CH Confi)uration LNCEL *rachConf%nde+ LNCEL LNCEL LNCEL NCEL : Power :am*in) LNCE LNCEL LNCEL LNCEL LNCEL Pream6le 1eneration LNCEL LNCEL LNCE LNCELL LNCEL LNCEL LNCEL LNCEL LNCEL : Procedure
*rachFre"Off raCont:esora5mallolUl ul* ul*ciniP iniPrrePwr Pwr *rachPwr:am* *ream6-+Ma+ delta deltaPr PreMs eMs)3 )3 rootse"%nde+ *rachC5 *rac *rachH hHsF sFla la) ) raNondedPream6 raPre1r5ie ra5mallolUl raMs)P raMs)Poff1r off1rB B
Huawei MO Parameter MO :CHCf) PrachConfi)%nde+Cf)%nd :CHCf) PrachConfi)%nde+ :CHCf) PrachFre"Offset :CHCf) Contention:esolution-imer :CHCf) Messa)e5ie1rou* :C :CHCf) Pream6% m6%nit:c it:c77-ar ar) )etPwr EUtranC anCellFD llFDD D :CHCf) Pwr:am*in)5te* :CHCf) Pream6le-ransMa+ CellU CellUl*c l*cCom Comm m Delt DeltaP aPre ream am6le 6leMs) Ms)3 3 Cell :oot5e"uence%d+ EUtranCellFDD Cell Cell:adius EUtranCellFDD ENod ENodeB eBl l) )o5wi o5wittch Hi)h Hi)h5* 5*ee eed: d:oo oot5 t5e" e"C5 C55w 5wit itch ch :CHCf) :andomPream6le:atio EUtranCellFDD :CHCf) :aPream6le1r*:atio :CHCf) Messa)e5ie1rou*
Ericssons Parameter
*ream6le% le%nit nitial: ial:e ecei7e i7ed-ar)etPow tPowe er
rach:oot5e"uence cell:an)e cfraEna6le
Random Access Access Procedure Procedure
RA Procedure • Random access procedure handled by MAC and PHY Layer through PRACH (in UL) and PDCCH ( in DL) and occupies 6 resource blocks blocks in a subframe • RACH only carries the preambles and Process: • UEs selects randomly a preamble from the list of preambles broadcasted in the BCCH calculates s OLPC parameter parameters s ( Initial Tx Power) Power) • UE calculate • Checks contention parameters (i.e. max. number of retries) • UE transmits initial RACH and waits for a response before retry. Open loop PC ensures that each retry will be at a higher power level. power adjustment and timing advance advance • Upon receipt of successful UL RACH preamble, eNB calculates power parameters together with an UL capacity grant ( so UE can send more info )
Not detected DL Next PRACH resource
PRACH response On the resources indicated by PDCCH
RA Procedure The contention based random access procedure follows these steps:
raRespWinSize Window size for RA response (in TTI) LNCEL; 2 (0), 3 (1), 4 (2), 5 (3), 6 (4), 7 (5), 8 (6), 10 (7); 10 TTIs (7)
(1) A preamble will be selected by UE and transmitted in the available subframe. Based on correlati correlation on the eNB may detect the access access and furthermore furthermore can measure the timing of the UE transmission. (2) The eNB answers answers using the same preamble preamble and at this point a timing timing advance will be fixed. Information on the scheduled resource will be exchanged and a temporary C-RNTI will be assigned. (3) The UE sends its id. The type of id depends on the state. In case of idle state NAS info has to be provided (IMSI, TMSI) else the C-RNTI is used. contention resolution resolution is performed performed,, i.e. the eNB addresses addresses the UE using (4) The contention the C-RNTI.
,1
.
raContResoT TPC command indicated in message 2 related to message 3 power p ower LNCEL; -6...8dB;2dB; 0dB
Max. Time for cont. resol. LNCEL; 8ms (0), 16ms (1), 24ms (2), 32ms (3), 40ms (4), 48ms (5), 56ms (6), 64ms (7); 32ms (3)
Random 3ccess Preamle
Random 3ccess Res#onse
5
ulpcRarespTpc
e2B
/
Scheduled 4ransmission
Contention Resolution
%
RA Procedure The contention free random access procedure • E.g. during handover a temporary valid preamble will be issued. • It is (temporarily) dedicated to this UE. • No contention resolution is needed as the preamble shall not be used by other UEs.
Random Access Power Ramping
RA Power Ramping PPRACH = min{ Pmax, PREAMBLE_RECEIVED_TARGET_POWER PREAMBLE_RECEIVED_TARGET_POWER + PATHLOSS} prachPwrRamp Power increment step LNCEL; 0dB (0), 2dB (1), 4dB (2), 6dB (3); 2dB (1)
BCH information UE sets the initial transmission power of RACH and send preamble signal
preambTxMax Max. RA transmissions LNCEL; 3 (0), 4 (1), 5 (2), 6 (3), 7 (4), 8 (5), 10 (6), 20 (7); 8 (5)
Preamble (RACH)
Values 50 (8), 100 (9), 200 (10) also defined but should not be used
Preamble (RACH)
Preamble (RACH) (RACH) PDCCH
Random access message (UL-SCH)
ulpcIniPrePwr Initial received target power LNCEL; -120 dBm (0), -118 dBm (1), -116 dBm (2), -114 dBm (3), 112 dBm (4), -110 dBm (5), -108 dBm (6), -106 dBm (7), -104 dBm (8), -102 dBm (9), -100 dBm (10), -98 dBm (11), -96 dBm (12), -94 dBm (13), -92 dBm (14), -90 dBm (15); -104 dBm (8)
Preamble Genera Preamble Generation tion
Preamble Generation 64 preambles made of Zadoff-Chu sequences with zero correlation zone: • given by the logical index RACH_ROOT_SEQUENCE • Zadoff Chu sequence u is given by
xu (n ) = e
− j
un ( n+1)
π
N ZC
,
0 ≤ n ≤ N ZC − 1
xu ,v (n) = xu ((n + C v ) mod N ZC )
• ZC sequence of length 839 (prime number) is used • 838 different root sequences available. (PRACH Root Sequence). Also different cyclic shifts can be used depending on cell size • Sub-carrier spacing is 1.25 kHz
rootSeqIndex LNCEL;0…837;1; 0
Preamble Generation Root Zadoff-Chu sequence order for prea preambl mble e format formats s 0 – 3.:
First: take all available cyclic shifts of one root Zadoff-Chu sequence: If not enough: take next logical index and so on prachCS Preamble cyclic shift (Ncs configuration) LNCEL;0…15;1; 0 Restricted set (high speed) in RL40
prachHSFlag Unrestricted or restricted (high speed) set selection LNCEL; true, false; false Only unrestricted set could be selected in RL30
• Cyclic shift given by
C v
=
v = 0 ,1 ,..., N ZC N C S − 1, N C S vN CS N CS = 0 0 d v n RA v RA RA RA RA RA + ( m o d nsh ift ) N C S v = 0, 1, ... , nsh ift ng ro u p + nshift − 1 s h i ft start
≠
0
f o r u n r e s t ri c t e d s e t s for unrestricted sets for restricted sets
Preamble generation
-Exercise Consider a cell of 37 km radius. Provide a sensitive setting for the cell size dependent parameter p arameters s
Support of high speed users •
If prachHsFlag = true the following rootSeqIndex values can be selected depending on prachCS (restricted set) Celll range Cel range
Requir Required ed amoun amountt of root sequences
prachCS
Possible range for rootSeqIndex
< 1 .0 k m
4
0
24...816
< 1 .4 k m
6
1
3 0 …8 1 0
< 2 .0 k m
6
2
3 6 …8 0 4
< 2 .6 k m
8
3
4 2 …7 9 6
< 3 .4 k m
9
4
5 2 …7 8 7
< 4 .3 k m
11
5
64…779
< 5 .4 k m
14
6
76…764
< 6 .7 k m
17
7
90…749
< 8 .6 k m
20
8
116…732
< 10 .6 k m
26
9
136…704
< 13 .2 k m
32
11
1 6 8 …6 7 6
< 17 .2 k m
44
11
2 0 4 …5 2 6
< 21 .5 k m
64
12
2 6 4 …5 6 6
< 27 .7 k m
64
13
3 2 8 …4 9 8
< 32 .8 k m
64
14
3 8 4 …4 5 0
Preamb Pre amble le gen generat eration ion – Hig High h Spe Speed ed Cas Case e highspeed set no delay spread
With preamble delay spread = 5,2 µs guard
NCs Configuration NCS
sign. per root seq.
#root seq. µs
km
µs
km
Guard
NCS
µs
km
µs
km
0 1 2 3
15 18 22
18 15 12
4 6 6
14.3 17.2 21.0
2.15 2.57 3.15
9.1 12.0 15.8
1.37 1.79 2.37
2.25 2.25 2.25
12.75 15.75 19.75
12.2 15.0 18.8
1.82 2.25 2.82
7.0 9.8 13.6
1.04 1.47 2.04
4 5 6
26 32 38 46
10 8 7 6
8 9 11 14
24.8 30.5 36.2 43.9
3.72 4.58 5.44 6.58
19.6 25.3 31.0 38.7
2.94 3.80 4.66 5.80
2.25 2.25 2.25 2.25
23.75 29.75 35.75 43.75
22.6 28.4 34.1 41.7
3.40 4.26 5.11 6.26
17.4 23.2 28.9 36.5
2.62 3.48 4.33 5.48
7 8 9 10
55 68 82 100
4 4 3 2
17 20 26 32
52.4 64.8 78.2 95.4
7.87 9.73 11.73 14.30
47.2 59.6 73.0 90.2
7.09 8.95 10.95 13.52
2.25 2.25 2.25 2.25
52.75 65.75 79.75 97.75
50.3 62.7 76.0 93.2
7.54 9.40 11.41 13.98
45.1 57.5 70.8 88.0
6.76 8.62 10.63 13.20
11 12 13
128 158 202
2 1 1
44 64 64
122.1 150.7 192.6
18.31 22.60 28.89
116.9 145.5 187.4
17.53 21.82 28.11
2.25 2.25 2.25
125.75 155.75 199.75
119.9 148.5 190.5
17.99 22.28 28.57
114.7 143.3 185.3
17.21 21.50 27.79
14
237
1
64
226.0
33.90
220.8
33.12
2.25
234.75
223.8
33.58
218.6
32.80
Support of high speed users
If prachHsFlag = true = true then hsScenario must be configured
hsScenario: defines highspeed scenario for a cell. Scenario 1 (open space scenario) and scenario 3 (tunnel scenario). Scenarios are described in 36.141 Annex B.3
Preamb Pre ambles les - Con Conten tentio tion n and Non-Co Non-Conte ntenti ntion on
64 preambles per cell raNondedPreamb Total number of non dedicated RA preambles LNCEL; 4 (0), 8 (1), 12 (2), 16 (3), 20 (4), 24 (5), 28 (6), 32 (7), 36 (8), 40 (9), 44 (10), 48 (11), 52 (12), 56 (13), 60 (14), 64 (15); 1 ; 40 (9)
Remaining are Non Contention Based Contention Based
Non Contention Based
Non-Dedicated preambles
Dedicated preambles
Type A and B Grouping of Preambles The contention based Random Access preambles are grouped into: requesting sting a normal normal UL resourc resource. e. • Type A - for reque • Type B - for requesti requesting ng a larger larger resource resource due due to Message Size AND Pathloss (PL) criteria having been met. raNondedPreamb
raPreGrASize
?
64 preambles per cell
?
raPreGrASize Random Access Preambles Group A Size LNCEL; 4 (0), 8 (1), 12 (2), 16 (3), 20 (4), 24 (5), 28 (6), 32 (7), 36 (8), 40 (9), 44 (10), 48 (11), 52 (12), 56 (13), 60 (14) ; 1 ; 32 (7)
raNondedPreamb Contention Based Remaining are Type B raPreGrASize Type A Preambles
Type B Preambles
Type B Criteria The Type B Random Access preambles are used if: • The message size is greater than raSmallVolUl.
Small Size Random Access Data Volume In Uplink LNCEL; 56 bits (0), 144 bits (1), 208 bits (2), 256 bits (3) ;1 ; 144 bits (1)
AND
•
raSmallVolUl
the pathloss is less than:
PCMAX – preambleInitialReceivedTarget preambleInitialReceivedTargetPower Power - deltaPreambleMsg3 - messagePowerOffsetGroupB Where: PCMAX is the UE maximum output power. ulpcIniPrePwr
deltaPreMsg3
Preamble Initial Received Target Power LNCEL; LNC EL; -120 -120 dBm dBm (0), (0), -118 dBm dBm (1), (1), 116 d dBm Bm (2), (2), -114 -114 dBm dBm (3), (3), -112 -112 dBm (4), (4), -110 dBm dBm (5), (5), -108 dBm dBm (6), (6), -106 dBm (7), (7), -104 -104 dBm dBm (8), (8), -10 -102 2 dBm dBm (9), (9), -100 -100 dBm (10), (10), -98 -98 dBm (11), (11), -96 -96 dBm (12), (12), -94 -94 dBm (13), (13), -92 -92 dBm (14), (14), -90 -90 dBm (15) (15);1 ;1 ; -1 -104 04 dB dBm m (8 (8))
Delta Preamble Random Access Message 3 LNCEL; -1...6 ;1 ; 0
raMsgPoffGrB RA Message Power Offset For Group B Selection Sele ction LNCEL; -infinity (0), 0 dB (1), 5 dB (2), 8 dB (3), 10 dB (4), 12 dB (5), 15 dB (6), 18 dB (7) ;1 ; 10 dB (4)
!A"# $OU
