02 RA41212EN10GLA1 Channel Config

RA41212EN10GLA1

Channel Configuration

1

1 © Nokia Siemens Networks RA41212EN10GLA1

LTE Radio Parameters RL10


RA41212EN10GLA1


2


Nokia Siemens Networks Academy

Legal notice

Intellectual Property RightsAll copyrights and intellectual property rights for Nokia Siemens Networks training documentation, product documentation and slide presentation material, all of which are forthwith known as Nokia Siemens Networks training material, are the exclusive property of Nokia Siemens Networks. Nokia Siemens Networks owns the rights to copying, modification, translation, adaptation or derivatives including any improvements or developments. Nokia Siemens Networks has the sole right to copy, distribute, amend, modify, develop, license, sublicense, sell, transfer and assign the Nokia Siemens Networks training material. Individuals can use the Nokia Siemens Networks training material for their own personal self-development only, those same individuals cannot subsequently pass on that same Intellectual Property to others without the prior written agreement of Nokia Siemens Networks. The Nokia Siemens Networks training material cannot be used outside of an agreed Nokia Siemens Networks training session for development of groups without the prior written agreement of Nokia Siemens Networks.

RA41212EN10GLA1


3


1. LTE Functionalities and Overview

2. Channel Configuration

3. General parameter DB structure and System Information Broadcast

4. Random Access

5. Radio Admission Control (RAC)

6. Radio Bearer Control & DRX /DTX Management

7. LTE Mobility Management

8. UL/DL Scheduler

9. MIMO Mode Control (MIMO-MC)

10.Power Control

Presentation / Author / Date

Contents

RA41212EN10GLA1


4


Module Contents

• Overview

• DL Channels and Signals

• UL Channels and Signals

RA41212EN10GLA1


5


Overview - ChannelsUpper Layers

RLC

MAC

PHY

Logical channels

Transport channels

BC

CH

CC

CH

PC

CH

MT

CH

MC

CH

BC

H

PC

H

DL

-SC

H

RA

CH

UL

-SC

H

PB

CH

PD

SC

H

PH

ICH

PD

CC

H

PC

FIC

H

PM

CH

PU

CC

H

PR

AC

H

PU

SC

H

MC

H

CC

CH

DC

CH

DT

CH

ULDL

Air interface

DC

CH

DT

CH

RA41212EN10GLA1


6


eNode B

PDCCH

PDSCH

CQI, PMI, RI,

ACK/NACK

SR

RNTI

DL scheduling

UL Grant

UL PWRC

n x per cell

DL controlconfiguration

1x per cell

PCFICH

PHICH

HARQ Info

PUSCHPUCCH

CQI, PMI, RI,

ACK/NACK

Overview – Control Information

*PWRC = Power Control

RA41212EN10GLA1


7


DL Physical Channels Allocation• PBCH:

– Occupies the central 72 subcarriers across 4 symbols

– Transmitted during second slot of each 10 ms frame on all antennas

• PCFICH:

– Transmitted during the first symbol of each TTI

– Occupies up to 16 RE per TTI

• PHICH:

– Tx during 1st symbol of each TTI or alternativ during symbols 1 to 3 of each TTI PhichDur

– Each PHCIH group occupies 12 RE

• PDCCH:

– Occupies the REs not used by PCFICH and PHICH and Reference Signals within the first 1, 2 or 3 symbols of each TTI (case 1.4 MHz: within the first 2, 3 or 4 symbols)

– In RL09/10: configuration static by MaxNbrOfOFDMSymsForPDCCH

• PDSCH:

– Is allocated the RE not used by signals or other physical channels

RB

PhichDur

PHICH on symb. 1 / 1- 3

LNCEL; 0; 1; 0

maxNrSymPdcch

max. # OFDM symbols for PDCCH

LNCEL; 1..3; 1; 3

A PICH is defined by its PHICH group number and an orthogonal sequence number within the group. A PHICH group is a set of PHICH transmitted in the same set of RE. For normal CP, 8 UEs can be addressed with 1 PHICH group

RA41212EN10GLA1


8


UL Physical Channels

• PUSCH: Physical Uplink Shared Channel

– 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

• PUCCH: Physical Uplink Control Channel

– Carries H-ARQ Ack/Nack indications, uplink scheduling request, CQIs and MIMO feedback

– Only control information is sent. The UE uses Resources Element at the edges of the channel

• PRACH: Physical Random Access Channel

– For Random Access attempts. PDCCH indicates the resource elements for PRACH use

– PBCH contains a list of allowed preambles (64 per cell) and the required length of the preamble.

RACH

CCCH DCCH DTCH

UL-SCH

PRACHPUSCH PUCCH

Logical

Transport

PHYS.

RLC

MAC

RA41212EN10GLA1


9


Generic - Bandwidth• 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

• Exercise: Describe bandwidths in terms of RBs

ulChBw / dlChBw

LNCEL; 5; 10; 20; 10 MHz

RA41212EN10GLA1


10


Generic - Carrier Frequency and Bandwidth (FDD)

100 kHz

... ...

FUL = FUL_low + 0.1(NUL – NOffs-UL)

FDL = FDL_low + 0.1(NDL – NOffs-DL)

Example (band 12)

UL: 708 MHz = 698 MHz + 0.1 (23100 – 23000) MHz

DL: 738 MHz = 728 MHz + 0.1 (5100 – 5000) MHz

EARFCN

NUL : earfcnUL

NDL : earfcnDL

Bandwidth

UL: ulChBw

DL: dlChBw

*Noffs-DL & Noffs-UL specified by

TS 36.101 for each band

earfcnUL/ DLLNCEL; 0...65535; 1; -

Note: Supported bandsRL10: Band 1, 4, 7, 10, 20

RA41212EN10GLA1


11


Generic - Physical Layer Cell Id• Physical Layer Cell Identity defines a cell.

• 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 synchronisation using primary and secondary sync signal

Strongest Signal

Primary Synchronization Signal

Secondary Synchronisation Signal

L1 id, slot (0/10)

Physical Layer Cell ID, Frame

Alignment

Cell ID Group 0(3 L1 id’s)

Group 167

Cell ID Group i(3 L1 id’s)168 Cell ID

groups

Phy L Cell ID

• PSS/SSS are used for:– Initial cell search and neighbor cell search

• As a result of cell search the UE should acquire:– PHY cell ID– DL center frequency– 10ms and 5ms timing– CP length– Duplex mode (TDD/FDD)

phyCellId:Physical Cell IdLNCEL; 0..503; 1; -(Range; Step; Default)

Physical layer cell identity defines a cell uniquely. It consists of two parts; physical layer cell identity group and physical layer identity, and is calculated with the following formula:

physical layer cell identity = 3 x physical layer cell identity group + physical layer identity.

Guidance for configuration:

Neighbor cells should have different values, and in a three cell eNB all cells should have phyCellId which belongs to same physical layer cell identity group. For example, in a three cell eNB, good PhyCellIds values are 0, 1, 2

RA41212EN10GLA1


12


Generic - Time Structure (Frame Type 1)

19

144 Ts = 4.69 µs

160 Ts

CP Symbol CP Symbol CP Symbol CP Symbol CP Symbol CP Symbol CP Symbol

CP Symbol

512 Ts = 16.7 µs

CP Symbol CP Symbol CP Symbol CP Symbol CP Symbol

CP Symbol

1024 Ts = 33.3 µs

CP Symbol CP Symbol

0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 0

Radio frame = 10 ms

subframe = 1 ms

Cyclic Prefixx2047-Ncp, … x2047

Cyclic Prefixx2047-Ncp, … x2047

OFDM Symbol (Time Domain Samples)x0, x1, …, x2047

OFDM Symbol (Time Domain Samples)x0, x1, …, x2047

Symbol Tsym = 2048 Ts = 66.67 µsTcp = Ncp Ts

Δf = 15 kHz, UL/DL - Extended Prefix

Δf = 7.5 kHz, UL/DL - Extended Prefix

Δf = 15 kHz, UL/DL - Normal Prefix

Slot = 15360 Ts = 500µs

CycPrefix

UL/DL CP config/length

LNCEL; 0 (Normal); 0

RA41212EN10GLA1


13


Generic – Time Structure and CP length

Short cyclic prefix:

Long cyclic prefix:

Copy= Cyclic prefix

= Data

5.21 μs

16.67 μs

• 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 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 (5.21μs and remaining symbols CP= 144 x Ts ( 4.7μs)

▪ Extended CP: CP length for all symbols in the slot is 512 x Ts ( 16.67µs)

Ts: ‘sampling time’ of the overall channel. Basic Time Unit.

Ts =1 sec

Subcarrier spacing X max FFT size

Ts = 32.5nsec

Subcarrier spacing= 15kHz; max. FFT size= 2048

RA41212EN10GLA1


14


Module Contents

• Overview



RA41212EN10GLA1


15


DL - Channels and Signals Overview

Upper Layers

RLC

MAC

BC

CH

CC

CH

PC

CH

MT

CH

MC

CH

BC

H

PC

H

DL

-SC

H

PB

CH

PD

SC

H

PH

ICH

PD

CC

H

PC

FIC

H

PM

CH

MC

H

Air interface

DC

CH

DT

CH

Syn

ch

RS

PHY

HI

CF

I

DC

I

RA41212EN10GLA1


16


180 kHz

0.5 ms

Secondary Synchronisation Signal (SSS)

Primary Synchronisation Signal (PSS)

DTX

Slot id: 0 1 2 . . ..10.. ..19 0 1

Synch Signals – Time and Frequency

Cell ID:

One of 504 IDs detected from the index of PSS and the combination of two SSS segments

CP length:

Detected from the relative PSS-to-SSS time distance

TDD/FDD:

Detected from the relative PSS-to-SSS time distance

5ms timing:

Detected from PSS time position

10ms timing:

Detected from the interlaced SSS segments swapping:

RA41212EN10GLA1


17


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)

RA41212EN10GLA1


18


Incremental Time-Frequency Structure of Cell-specific Reference Signal

0=l0R

0R

0R

0R

6=l 0=l0R

0R

0R

0R

6=l

Resource element (k,l)

Not used for transmission on this antenna port

Reference symbols on this antenna port

0=l0R

0R

0R

0R

6=l 0=l0R

0R

0R

0R

6=l 0=l

1R

1R

1R

1R

6=l 0=l

1R

1R

1R

1R

6=l

0=l0R

0R

0R

0R

6=l 0=l0R

0R

0R

0R

6=l 0=l

1R

1R

1R

1R

6=l 0=l

1R

1R

1R

1R

6=l 0=l 6=l 0=l

2R

6=l 0=l 6=l 0=l 6=l2R

2R

2R

3R

3R

3R

3R

even-numbered slots odd-numbered slots

Antenna port 0


Antenna port 1


Antenna port 2


Antenna port 3

Resource Element (RE) k, l

Not used for transmission on this antenna port (DTX)

Reference symbols (RS) on this antenna port

l=0 ……...... 6, 0 ……….. 6l=0 ……...... 6, 0 ……….. 6

l=0 ……...... 6, 0 ……….. 6

Antenna port 0 Antenna port 1 Antenna port 2 Antenna port 3

Fo

ur

an

ten

na

po

rts

Tw

oa

nte

nn

ap

ort

sO

ne

an

ten

na

po

rt

RA41212EN10GLA1


19


Physical Broadcast Channel

• PBCH carriers essential system information like:– DL BW configuration

– PHICH configuration

– System Frame Number (8 MBS bits)

• PBCH enables blind detection of:– DL antenna configuration {1TX, 2TX, 4TX} via CRC masking*

– 40 ms timing (2 LSB bits of SFN) via 40ms scrambling

* for decoding the CRC (Cyclic Redundancy Check) each MIB is masked with a codeword representing the number of transmit antenna ports.

Frequency:

Occupies central 72 sub-carriers (excluding the DC)

Time:

TTI/scrambling period: 40ms

Duration: first 4 OFDM symbols in slot #1

TBS:

Fixed TB size of 40 bits (including 16 bit CRC)

Transmission Scheme:

QPSK, Tail Biting Convolutional Coding

TX diversity: none, SFBC, SFBC-FSTD depending on the number of cell-specific antenna ports

The System Frame Number is provided to synchronize the UE with eUTRAN

total SFN is 10 bit long

• eNodeB dynamically broadcast the 8 MSB of SFN to UE (i.e. inside MIB)• UE implicitly can decode the 2 least significant bits from SFN to identify

the TTI for MIB de-interleaving

00 first radio frame

01 second radio frame

10 third radio frame

11 last (fourth) radio frame

RA41212EN10GLA1


20


Physical Layer Downlink DL-Physical Data & Control Channels

PBCHPBCH

PBCH

Synchronization signals

Reserved for reference singals

Remark: PBCH does not use blocks reserved for reference signals

Code and rate-matching (repetition) to number of bits available on PBCH in 40 ms

One MIB (information bits + spare bits + CRC)

40 ms transmission time interval of PBCH

One radio frame

6 R

Bs

Use

d ba

ndw

idth

1 R

B

One subframe (2 slots) 1 ms

Segmentation into four equal sized individually self-decodable units

PBCH Structure:

Frequency:

- Occupies central 72 subcarriers (excluding DC)

Time:

- TTI / scrambling period: 40ms

- Duration: first OFDM symbols in slot #1

TBS:

- Fixed TB size of 40 bits (including 16 bit CRC)(MIB = 14 Bits / Spare Bits = 10 / CRC 16 Bits)

(Available bits in 40ms = 1920 in case of normal cyclic prefix)

Transmission Scheme:

- QPSK, Tail Biting Convolution Coding

- Tx diversity: none, SFBC (Space-Frequency Block code), SFBC-FSTD (Frequency Switched Transmit Diversity-SFBC) depending on the number of cell-specific antenna ports. In addition for decoding the CRC (CyclicRedundancy Check) on each MIB is masked with a codeword representing the number of transmit antenna ports.

RA41212EN10GLA1


21


Physical Layer Downlink DL-Physical Data & Control Channels

PCFICHPCFICH

• 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 use (see table below)

CFI CFI codeword <b0, b1, b2,……b31>

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 (1Tx, SFBC, SFBC-FSTD)

– Cell specific offset is added

– Cell specific scrambling

RA41212EN10GLA1


22


PCFICH Mapping to Resource Elements

• The mapping is done in terms of quadruplets of modulation symbols for each antenna port

• A quadruplet is defined as d(4i), d(4i+1), d(4i+2), d(4i+3)

• Reference symbols REs are always reserved for at least 2Tx antennas

• The four quadruplets shall be mapped to four resource element groups (REG) (aka mini-CCE) in the first OFDM symbol

– Example: 72 subcarriers case (1.4 MHz):

( ) ( )DLRB

cellID

RBsc 2mod2 NNNk ⋅=

Starting position depends on cell id

Distance between mini-CCEs

Ant 0

Ant 1

frequency

d0 d1 d2 d3

-d1 d0 -d3 d2* * * *

22 RBsc

DLRB NN ⋅

Ant 0

Ant 1

frequency

d0 d1

d2 d3

-d1 d0

-d3 d2

* *

* *

Ant 2

Ant 3

frequency

Resource element group

Start position depends on cell id

Distance between mini-CCE = 18 for 72 RB case

Nsc(rb) is the number of subcarriers in frequency domain for one resource block

See TS 36.211 for details

RA41212EN10GLA1


23


PHICH• For HARQ ACK/NACK signaling the PHICH is deployed. • A PHICH is defined by its PHICH group number and an

orthogonal sequence number within the group.• PHICH modulation is BPSK. Applying I/Q separation

and an SF=4 yields 8 orthogonal sequences for normal CP. SF 2 is in use in case of extended CP, hence there are 4 orthogonal sequences. I,e. in total there may be 8 .. 224 PHICHs in one subframe.

• Example:, BW=15 subcarriers normal CP, Ng=1/6, 1 PHICH group. 12 symbols are to be transmitted.

• NRBDL : DL BW / RBs

• Ng = 1/6, 1/2, *1,* 2. setting: phichRes

( ) ( )

⋅=

prefix cyclic extendedfor 82

prefix cyclic normalfor 8DLRBg

DLRBggroup

PHICHNN

NNN

+j -j -j +j7

+j +j -j -j6

+j -j +j -j5

+j +j +j +j 4

+j -j+1 -1 -1 +13

+j +j+1 +1 -1 -12

+1 -1+1 -1 +1 -11

+1 +1+1 +1 +1 +1 0

Extended CPNormal CP

Orthogonal sequenceSequence Index

+j -j -j +j7

+j +j -j -j6

+j -j +j -j5

+j +j +j +j 4

+j -j+1 -1 -1 +13

+j +j+1 +1 -1 -12

+1 -1+1 -1 +1 -11

+1 +1+1 +1 +1 +1 0

Extended CPNormal CP

Orthogonal sequenceSequence Index

Number of RBs

phichRes

#PHICH groups

LNCEL; 1/6; ½; 1; 2; 1/6

phichRes 1/6 1/2 1 2

#PHICH groups 2 4 7 13

# scheduled UE 16 32 56 104

e.g. 10 MHz*Necessary with semi-persistent scheduling

RA41212EN10GLA1


24


PHICH Association and Resource Indication

• PHICH duration:– 1 or 3 OFDM symbols in normal subframes (indicated via PBCH)

– 1 or 2 OFDM symbols in MBSFN subframes and in DwPTS (Downlink Pilot Time Slot)

• PHICH linked to UL PRB

• Scattered grouping - spreads out the PHICH of adjacent PRBs to different PHICH groups

• 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

PhichDurPHICH on symb. 1 / 1- 3

LNCEL; 0; 1; 0

DM-RS CS: Demodulation Reference Signal Cyclic Shift

RA41212EN10GLA1


25


PDCCH Overview

• The PDCCH carries the UL & DL scheduling assignments

• A PDCCH is transmitted on an aggregation of one 1, 2, 4 or 8 control channel elements (CCE). A CCE consists of 36 REs

• The aggregations of CCEs have a tree structure, where an aggregation consisting of n CCEs starts on position (i mod n), where i is the CCE number

• Further restrictions on the aggregations are defined with a Hashing function

Aggregation of 1 CCE

Aggregation of 2 CCEs



0 1 102 3 4 5 6 7 8 9 11 12 13 14 15 16 17 18 19 20 21 22 23CCE number

pdcchAggDefUE

PDCCH LA UE default aggregation; used, when enableAmcPdcch disabled or no valid CQI exists

LNCEL; 1, 2, 4, 8; 4

Note:

Not necessary for semi-persistent users

enableAmcPdcch

Enable AMC for PDCCH Link Adaptation

LNCEL; true/false; true

The target error probability for a missed detection of a PDCCH is 10-2

RA41212EN10GLA1


26


DL - L1/L2 control info: PDCCH Resources• The MaximumNumberOfOFDMSymbolsForPDCCH parameter defines how many OFDM

symbols can be used. • eNB selects the actual value for each TTI, which is signalled to UE in PCFICH. (Note, RL09

and RL10 uses fix allocation)• Range: 1, 2, 3 (BW > 1.4 MHz); • Range: 2, 3, 4 (BW = 1.4 MHz)• setting: maxNrSymPdcch• Example shows dynamic case for MaximumNumberOfOFDMSymbolsForPDCCH=3

(yellow)

maxNrSymPdcch

LNCEL; 1..3; 1; 3

RA41212EN10GLA1


27


Physical Layer Downlink SummaryDL-Physical Data & Control Channel

DLDL--Channel Channel OverviewOverview

Cen

tral

72

subc

arrie

rs (

6 R

Bs)

Tot

al S

yste

m B

andw

idth

e.g

. 10

MH

z (5

0 R

Bs)

Fre

quen

cy

RA41212EN10GLA1


28


PDCCH Rsvd Rsvd PBCHPBCHPBCHPBCH PDCCH PDCCH PDCCH PDCCH PDCCH Rsvd Rsvd PDCCH PDCCH PDCCH PDCCHPDCCH Rsvd Rsvd PBCHPBCHPBCHPBCH PDCCH PDCCH PDCCH PDCCH PDCCH Rsvd Rsvd PDCCH PDCCH PDCCH PDCCHRef. Ref. Rsvd Rsvd Ref. Rsvd PBCHPBCHRef. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Rsvd Rsvd Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref.PDCCH Rsvd Rsvd PBCHPBCHPBCHPBCH PDCCH PDCCH PDCCH PDCCH PDCCH Rsvd Rsvd PDCCH PDCCH PDCCH PDCCHPDCCH Rsvd Rsvd PBCHPBCHPBCHPBCH PDCCH PDCCH PDCCH PDCCH PDCCH Rsvd Rsvd PDCCH PDCCH PDCCH PDCCHRef. Ref. S-SynP-SynRef. Rsvd PBCHPBCHRef. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. S-SynP-SynRef. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref.PDCCH S-SynP-SynPBCHPBCHPBCHPBCH PDCCH PDCCH PDCCH PDCCH PDCCH S-SynP-Syn PDCCH PDCCH PDCCH PDCCHPDCCH S-SynP-SynPBCHPBCHPBCHPBCH PDCCH PDCCH PDCCH PDCCH PDCCH S-SynP-Syn PDCCH PDCCH PDCCH PDCCHRef. Ref. S-SynP-SynRef. Rsvd PBCHPBCHRef. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. S-SynP-SynRef. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref.PDCCH S-SynP-SynPBCHPBCHPBCHPBCH PDCCH PDCCH PDCCH PDCCH PDCCH S-SynP-Syn PDCCH PDCCH PDCCH PDCCHPDCCH S-SynP-SynPBCHPBCHPBCHPBCH PDCCH PDCCH PDCCH PDCCH PDCCH S-SynP-Syn PDCCH PDCCH PDCCH PDCCHRef. Ref. S-SynP-SynRef. Rsvd PBCHPBCHRef. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. S-SynP-SynRef. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref.PDCCH S-SynP-SynPBCHPBCHPBCHPBCH PDCCH PDCCH PDCCH PDCCH PDCCH S-SynP-Syn PDCCH PDCCH PDCCH PDCCHPDCCH S-SynP-SynPBCHPBCHPBCHPBCH PDCCH PDCCH PDCCH PDCCH PDCCH S-SynP-Syn PDCCH PDCCH PDCCH PDCCHRef. Ref. S-SynP-SynRef. Rsvd PBCHPBCHRef. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. S-SynP-SynRef. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref.PDCCH S-SynP-SynPBCHPBCHPBCHPBCH PDCCH PDCCH PDCCH PDCCH PDCCH S-SynP-Syn PDCCH PDCCH PDCCH PDCCHPDCCH S-SynP-SynPBCHPBCHPBCHPBCH PDCCH PDCCH PDCCH PDCCH PDCCH S-SynP-Syn PDCCH PDCCH PDCCH PDCCHRef. Ref. S-SynP-SynRef. Rsvd PBCHPBCHRef. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. S-SynP-SynRef. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref.PDCCH S-SynP-SynPBCHPBCHPBCHPBCH PDCCH PDCCH PDCCH PDCCH PDCCH S-SynP-Syn PDCCH PDCCH PDCCH PDCCHPDCCH S-SynP-SynPBCHPBCHPBCHPBCH PDCCH PDCCH PDCCH PDCCH PDCCH S-SynP-Syn PDCCH PDCCH PDCCH PDCCHRef. Ref. S-SynP-SynRef. Rsvd PBCHPBCHRef. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. S-SynP-SynRef. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref.PDCCH S-SynP-SynPBCHPBCHPBCHPBCH PDCCH PDCCH PDCCH PDCCH PDCCH S-SynP-Syn PDCCH PDCCH PDCCH PDCCHPDCCH S-SynP-SynPBCHPBCHPBCHPBCH PDCCH PDCCH PDCCH PDCCH PDCCH S-SynP-Syn PDCCH PDCCH PDCCH PDCCHRef. Ref. S-SynP-SynRef. Rsvd PBCHPBCHRef. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. S-SynP-SynRef. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref.PDCCH S-SynP-SynPBCHPBCHPBCHPBCH PDCCH PDCCH PDCCH PDCCH PDCCH S-SynP-Syn PDCCH PDCCH PDCCH PDCCHPDCCH S-SynP-SynPBCHPBCHPBCHPBCH PDCCH PDCCH PDCCH PDCCH PDCCH S-SynP-Syn PDCCH PDCCH PDCCH PDCCHRef. Ref. S-SynP-SynRef. Rsvd PBCHPBCHRef. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. S-SynP-SynRef. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref.PDCCH S-SynP-SynPBCHPBCHPBCHPBCH PDCCH PDCCH PDCCH PDCCH PDCCH S-SynP-Syn PDCCH PDCCH PDCCH PDCCHPDCCH S-SynP-SynPBCHPBCHPBCHPBCH PDCCH PDCCH PDCCH PDCCH PDCCH S-SynP-Syn PDCCH PDCCH PDCCH PDCCHRef. Ref. S-SynP-SynRef. Rsvd PBCHPBCHRef. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. S-SynP-SynRef. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref.PDCCH S-SynP-SynPBCHPBCHPBCHPBCH PDCCH PDCCH PDCCH PDCCH PDCCH S-SynP-Syn PDCCH PDCCH PDCCH PDCCHPDCCH S-SynP-SynPBCHPBCHPBCHPBCH PDCCH PDCCH PDCCH PDCCH PDCCH S-SynP-Syn PDCCH PDCCH PDCCH PDCCHRef. Ref. S-SynP-SynRef. Rsvd PBCHPBCHRef. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. S-SynP-SynRef. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref.PDCCH S-SynP-SynPBCHPBCHPBCHPBCH PDCCH PDCCH PDCCH PDCCH PDCCH S-SynP-Syn PDCCH PDCCH PDCCH PDCCHPDCCH S-SynP-SynPBCHPBCHPBCHPBCH PDCCH PDCCH PDCCH PDCCH PDCCH S-SynP-Syn PDCCH PDCCH PDCCH PDCCHRef. Ref. S-SynP-SynRef. Rsvd PBCHPBCHRef. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. S-SynP-SynRef. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref.PCFICH S-SynP-SynPBCHPBCHPBCHPBCH PCFICH PCFICH PCFICH PCFICH PCFICH S-SynP-Syn PCFICH PCFICH PCFICH PCFICHPCFICH S-SynP-SynPBCHPBCHPBCHPBCH PCFICH PCFICH PCFICH PCFICH PCFICH S-SynP-Syn PCFICH PCFICH PCFICH PCFICHRef. Ref. S-SynP-SynRef. Rsvd PBCHPBCHRef. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. S-SynP-SynRef. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref.PCFICH S-SynP-SynPBCHPBCHPBCHPBCH PCFICH PCFICH PCFICH PCFICH PCFICH S-SynP-Syn PCFICH PCFICH PCFICH PCFICHPCFICH S-SynP-SynPBCHPBCHPBCHPBCH PCFICH PCFICH PCFICH PCFICH PCFICH S-SynP-Syn PCFICH PCFICH PCFICH PCFICHRef. Ref. S-SynP-SynRef. Rsvd PBCHPBCHRef. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. S-SynP-SynRef. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref.PDCCH S-SynP-SynPBCHPBCHPBCHPBCH PDCCH PDCCH PDCCH PDCCH PDCCH S-SynP-Syn PDCCH PDCCH PDCCH PDCCHPDCCH S-SynP-SynPBCHPBCHPBCHPBCH PDCCH PDCCH PDCCH PDCCH PDCCH S-SynP-Syn PDCCH PDCCH PDCCH PDCCHRef. Ref. S-SynP-SynRef. Rsvd PBCHPBCHRef. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. S-SynP-SynRef. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref.PDCCH S-SynP-SynPBCHPBCHPBCHPBCH PDCCH PDCCH PDCCH PDCCH PDCCH S-SynP-Syn PDCCH PDCCH PDCCH PDCCHPDCCH S-SynP-SynPBCHPBCHPBCHPBCH PDCCH PDCCH PDCCH PDCCH PDCCH S-SynP-Syn PDCCH PDCCH PDCCH PDCCHRef. Ref. S-SynP-SynRef. Rsvd PBCHPBCHRef. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. S-SynP-SynRef. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref.PDCCH S-SynP-SynPBCHPBCHPBCHPBCH PDCCH PDCCH PDCCH PDCCH PDCCH S-SynP-Syn PDCCH PDCCH PDCCH PDCCHPDCCH S-SynP-SynPBCHPBCHPBCHPBCH PDCCH PDCCH PDCCH PDCCH PDCCH S-SynP-Syn PDCCH PDCCH PDCCH PDCCHRef. Ref. S-SynP-SynRef. Rsvd PBCHPBCHRef. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. S-SynP-SynRef. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref.PDCCH S-SynP-SynPBCHPBCHPBCHPBCH PDCCH PDCCH PDCCH PDCCH PDCCH S-SynP-Syn PDCCH PDCCH PDCCH PDCCHPDCCH S-SynP-SynPBCHPBCHPBCHPBCH PDCCH PDCCH PDCCH PDCCH PDCCH S-SynP-Syn PDCCH PDCCH PDCCH PDCCHRef. Ref. S-SynP-SynRef. Rsvd PBCHPBCHRef. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. S-SynP-SynRef. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref.PDCCH S-SynP-SynPBCHPBCHPBCHPBCH PDCCH PDCCH PDCCH PDCCH PDCCH S-SynP-Syn PDCCH PDCCH PDCCH PDCCHPDCCH S-SynP-SynPBCHPBCHPBCHPBCH PDCCH PDCCH PDCCH PDCCH PDCCH S-SynP-Syn PDCCH PDCCH PDCCH PDCCHRef. Ref. S-SynP-SynRef. Rsvd PBCHPBCHRef. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. S-SynP-SynRef. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref.PDCCH S-SynP-SynPBCHPBCHPBCHPBCH PDCCH PDCCH PDCCH PDCCH PDCCH S-SynP-Syn PDCCH PDCCH PDCCH PDCCHPDCCH S-SynP-SynPBCHPBCHPBCHPBCH PDCCH PDCCH PDCCH PDCCH PDCCH S-SynP-Syn PDCCH PDCCH PDCCH PDCCHRef. Ref. S-SynP-SynRef. Rsvd PBCHPBCHRef. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. S-SynP-SynRef. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref.PDCCH S-SynP-SynPBCHPBCHPBCHPBCH PDCCH PDCCH PDCCH PDCCH PDCCH S-SynP-Syn PDCCH PDCCH PDCCH PDCCHPDCCH S-SynP-SynPBCHPBCHPBCHPBCH PDCCH PDCCH PDCCH PDCCH PDCCH S-SynP-Syn PDCCH PDCCH PDCCH PDCCHRef. Ref. S-SynP-SynRef. Rsvd PBCHPBCHRef. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. S-SynP-SynRef. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref.PDCCH S-SynP-SynPBCHPBCHPBCHPBCH PDCCH PDCCH PDCCH PDCCH PDCCH S-SynP-Syn PDCCH PDCCH PDCCH PDCCHPDCCH S-SynP-SynPBCHPBCHPBCHPBCH PDCCH PDCCH PDCCH PDCCH PDCCH S-SynP-Syn PDCCH PDCCH PDCCH PDCCHRef. Ref. S-SynP-SynRef. Rsvd PBCHPBCHRef. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. S-SynP-SynRef. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref.PDCCH S-SynP-SynPBCHPBCHPBCHPBCH PDCCH PDCCH PDCCH PDCCH PDCCH S-SynP-Syn PDCCH PDCCH PDCCH PDCCHPDCCH Rsvd Rsvd PBCHPBCHPBCHPBCH PDCCH PDCCH PDCCH PDCCH PDCCH Rsvd Rsvd PDCCH PDCCH PDCCH PDCCHRef. Ref. Rsvd Rsvd Ref. Rsvd PBCHPBCHRef. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Rsvd Rsvd Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref.PDCCH Rsvd Rsvd PBCHPBCHPBCHPBCH PDCCH PDCCH PDCCH PDCCH PDCCH Rsvd Rsvd PDCCH PDCCH PDCCH PDCCHPDCCH Rsvd Rsvd PBCHPBCHPBCHPBCH PDCCH PDCCH PDCCH PDCCH PDCCH Rsvd Rsvd PDCCH PDCCH PDCCH PDCCHRef. Ref. Rsvd Rsvd Ref. Rsvd PBCHPBCHRef. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Rsvd Rsvd Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref. Ref.

PDCCH S-Syn P-Syn PBCH PBCH PBCH PBCH


Ref. Ref. S-Syn P-Syn Ref. Rsvd PBCH PBCH Ref.










1 ms subframe

1 resource block = 12 subcarriers = 180 kHz

=PDSCH

=PBCH

=Reference

=P-Synchronization

=PCFICH

=PDCCH

=PHICH

=Reserved for 4x4 MIMO

1.4 MHz =S-Synchronization

Physical Channel Resource AllocationOne Example Resource Block, subframe 0

RA41212EN10GLA1


29


Exercise: PDCCH Resources

Task:• Consider cell configuration: BW=50 PRB, 2 antenna ports, normal CP

• MaximumNumberOfOFDMSymbolsForPDCCH=2

• Ng = 1/6

Calculate the number of available PDCCHs.

Assume for frequency of occurancies of different aggregation levels (AL)

AL4 is 2 times the frequency of AL8

AL2 is 2 times the frequency of AL4

AL1 is 1/2 times the frequency of AL2

RA41212EN10GLA1


30


Solution: PDCCH ResourcesTask:• Consider cell configuration: BW=50 PRB, 2 antenna ports, normal CP • MaximumNumberOfOFDMSymbolsForPDCCH=3• Ng = 1/6

Calculate the max number of PDCCHs.

Solution:- 1st symbol yields 2 REGs per PRB x 50 PRB = 100 REGs (because of the reference signals)- 2nd yields each 3 x 50 = 150 REGs. Total: 250 REGs. (no reference signals )- 4 REGs for PCFICH, 2x3=6 for PHICH 240 REGs remain for PDCCH- 240 div 9 = 26 CCEs are available- For 1 distribution 1xAL8 + 2xAL4 + 4xAL2+2xAL1

- Aggregation level 8 1x = 8 CCEs- Aggregation level 4 2x = 8 CCEs- Aggregation level 2 4x = 8 CCEs- Aggregation level 1 2x = 2 CCEs26 CCEs are consumed for 9 PDCCH.Note: due to allocation constraints some might be blocked

RA41212EN10GLA1


31


Downlink Control Information (DCI)

• A DCI transports control information for one MAC ID, which is implicitly signaled in the CRC.

– Format 0▪ Used for defining the transmission of PUSCH assignments

– Format 1▪ Used for defining the transmission of PDSCH assignments for single codeword (SCW) operation

– Format 1A▪ Compact form for the transmission of PDSCH assignments for SCW operation*. Has same size as format 0

– Format 1B▪ Compact form like 1A but supports closed-loop rank 1 precoding

– Format 1C▪ Signaling for PCH, RACH & BCCH on DL SCH (aka dynamic BCCH)

– Format 1D▪ Like DCI 1A but supports power offsets for DL MU-MIMO and TPMI

– Format 2▪ Used for defining the transmission of DL-SCH assignments for Closed-Loop MIMO operation

– Format 2A▪ Used for defining the transmission of DL-SCH assignments for Open-Loop MIMO operation

– Format 3▪ Used for TPC commands for PUCCH and PUSCH with 2-bit power adjustments. Has same size as format 0

– Format 3A▪ Used for TPC commands for PUCCH and PUSCH with 1-bit power adjustments. Has same size as format 0

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

* allocating a dedicated preamble signature to a UE for contention-free random access

The information fields are multiplexed according to the order they are listed in each DCI format. The first bit of each information field corresponds to MSB.

RA41212EN10GLA1


32


Module Contents

• Overview



RA41212EN10GLA1


33


UL Channel Mapping

Upper Layers

RLC

MAC

PHY

RA

CH

CC

CH

DC

CH

DT

CH

Air interface

PR

AC

H

PU

SC

HU

L-S

CH

PU

CC

H

UC

I

DR

S

SR

S

RA41212EN10GLA1


34


UE Channel state information (CSI) feedback types in LTE

The purpose of CSI feedback is to provide the eNodeB information about DL channel state to help in the scheduling decision.

Compared to the WCDMA/HSPA, the main new feature in the channel feedback is the frequency selectivity of the report

CSI is measured by the UE and signaled to the eNodeB using PUCCH or PUSCH

Channel state information in LTE can be divided into three categories:

– CQI - Channel Quality Indicator

– RI - Rank Indicator

– PMI - Precoding Matrix Indicator

In general the CSI reported by the UE is just a recommendation

– The eNodeB does not need to follow it

The corresponding procedure for providing UL channel state information is called Channel Sounding; it is done using the Sounding Reference Symbols, SRS (not considered in this presentation)

(1) eNodeB transmission

(3) UE feedback

(2) UE CSI measurement

RA41212EN10GLA1


35


Channel Quality Indicator (CQI)

• The most important part of channel feedback is the CQI

• The CQI is defined as a table containing 16 entries with modulation and coding schemes (MCSs)

• The UE shall report back the highest CQI index corresponding to the MCS for which the transport block BLER shall not exceed 10%

CQI index modulation

coding rate x 1024

efficiency

0 out of range

1 QPSK 78 0.1523

2 QPSK 120 0.2344

3 QPSK 193 0.3770

4 QPSK 308 0.6016

5 QPSK 449 0.8770

6 QPSK 602 1.1758

7 16QAM 378 1.4766

8 16QAM 490 1.9141

9 16QAM 616 2.4063

10 64QAM 466 2.7305

11 64QAM 567 3.3223

12 64QAM 666 3.9023

13 64QAM 772 4.5234

14 64QAM 873 5.1152

15 64QAM 948 5.5547

UE reports highest MCS that it can decode with a TB Error rate < 10%

taking into account UE’s receiver characteristic

* Efficiency is defined as number of bits per resource elements

RA41212EN10GLA1


36


Rank Indicator (RI)

• Rank Indicator is only relevant when the UE is operating in MIMO modes with spatial multiplexing

– For single antenna operation or TX diversity it is not used

• RI is the UEs recommendation for the number of layers to be used in spatial multiplexing

• The RI can have values {1 or 2} with 2-by-2 antenna configuration and {1, 2, 3, or 4} with 4-by-by antenna configuration

• The RI is always associated to one or more CQI reports

RA41212EN10GLA1


37


Precoding Matrix Indicator (PMI)

• PMI provides information about the preferred Precoding Matrix

• Just like RI, also PMI is relevant to MIMO operation only– MIMO operation with PMI feedback is called Closed Loop MIMO

Example: codebook for 2 TX antennas

Codebook Number of layers υ

1 2

0

11

21

1

− 11

21

− 1111

21

2

j1

21

− jj11

21

3

− j1

21

* PMI NOT used in RL10

RA41212EN10GLA1


38


Periodic and Aperiodic Reporting

• The channel feedback reporting in LTE is divided into two main categories: Periodic and Aperiodic

Periodic reporting

• The baseline mode for CQI/PMI/RI 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 Reporting

• Aperiodic reports are explicitly triggered by the eNodeB using a specific bit in the PDCCH UL grant

• 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 to send Aperiodic reports only when it is scheduled, while periodic reports can provide coarse channel information on a regular basis

CQIAperEnable

enabling / disabling aperiodic CQI /RI/PMI reporting on PUSCH. LNCEL; false/true; true

cqiPerNp

CQI periodicity

LNCEL; 2; 5; 10; 20; 20 ms

RA41212EN10GLA1


39


CQI Aperiodic Reporting on PUSCH (1/2)

• Compared to the WCDMA/HSPA, the main new feature in the channel feedback is the frequency selectivity of the report

– This is an enabler for the Frequency Domain packet Scheduling (FDPS)

• Since providing a full 4-bit CQI for all the PRBs would mean excessive UL signaling overhead, some feedback compression schemes are used

• In order to reduce feedback, the CQI is reported per subband basis– The size of the subbands varies depending on the reporting mode and system

bandwidth

• The main compression methods are:– Wideband feedback

– Best-M average also called UE selected subband feedback

– Full Feedback also called Higher Layer Configured subband feedback

• Additionally, Delta compression can be used – E.g. in MIMO case the CQI for the 2nd Code Word can be signaled as a 3-bit

delta relative to the CQI of the CQI of the 1st CW

RA41212EN10GLA1


40


CQI Aperiodic Reporting on PUSCH (2/2)• Wideband feedback

– Only a single CQI value is fed back for the whole system band

– Cannot be utilized in FDPS

• Best-M average also called UE selected sub-band feedback– For the M best sub-band an average CQI value is reported

• Full Feedback also called Higher Layer Configured sub-band feedback– A separate CQI is reported for each sub-band using Delta compression

An example of Best-M Average reporting with 3 MHz BW (15 RBs means that the sub-band size is 2 RBs and the best 3 sub-bands are reported)

M = 3 best Subbands are selected and an average CQI value is reported

Channel SINR

Subband index 1 2 3 4 5 6 7 8PRB index 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15

BW / RB

Sub-band size

(RBs)

# best Sub-

bandsM

6-7 NA NA

8-10 2 1

11-26 2 3

27-63 3 5

64-110 4 6

RA41212EN10GLA1


41


CQI Periodic Reporting on PUCCH or PUSCH (1/2)

• Wideband feedback or UE selected sub-band

• Period configurable– 2, 5, 10, 16, 32, 40, 64, 80, 160 ms, off

• Wideband feedback similar to aperiodic reporting

• UE selected sub-band:– A single CQI result per report

– The total number of sub-bands is divided into J fractions called bandwidth parts

– Only the best sub-band per BW part is reported

– Example: for 3 MHz there are 4 RBs per sub-band so there are 15/4 = 4 sub-bands. Those 4 sub-bands are divided into 2 BW parts which means that there are 2 RBs per BW part.

• Configured by higher layer signaling BW / RB Subband Size k (RBs)

BW Parts (J)

6-7 NA NA

8-10 4 1

11-26 4 2

27-63 6 3

64-110 8 4

cqiPerMode

LNCEL; widebandCqiOnly (0), widebandAndSubbandCqi (1); 0

cqiPerNp

CQI periodicity

LNCEL; 2; 5; 10; 20; 20 ms

RA41212EN10GLA1


42


• cqiPerSimulAck controls whether UE need to report CQI simulatneous with HARQ ACK-NACK info

• For combined wideband and sub-band reporting operator can instruct UE how many sub-band reports of a the bandwidth parts should be included between 2 consecutive wideband CQI reports: cqiPerSbCycK

• For transmission modes 3 and 4 UE needs to know where is the position to send Rank Indicator realtive to CQI report LNCEL: riPerM defines multiplier for LNCEL: riPerOffset

– Current default is „Rank Indicator shall be sent exactely 1 TTI before CQI is sent“

– If, for example, subframe 5 is chosen for CQI reporting and riPerOffset is -1, then subframe 4 is chosen for the RI report.

CQI Periodic Reporting on PUCCH or PUSCH (2/2)cqiPerSimulAck

O&M switch for enabling / disabling simultaneous transmission of periodic CQI / RI / PMI feedback and HARQ ACK/NACK on PUCCH

LNCEL; true; true

cqiPerSbCyck

It is required only for configuring a periodic wideband + subband reporting.

LNCEL; 1…4; 1; 1

riPerM

offset for the periodic Rank Indicator reporting instance in relation to the CQI reporting subframe.

LNCEL; 1, 2; 1

riPerOffset

The offset tells the time shift for the periodic CQI/PMI reporting instance. LNCEL; -1…0; 1; -1

RA41212EN10GLA1


43


Categorization of CQI/PMI/rank reporting options

LTE CQI reporting family

tree

Periodic

Frequency selective

Aperiodic

Single CQI Full FeedbackBest-M Average

No PMI

Mode 2-0

24 bits

No PMI

Mode 3-0

30 bits

Multi PMI

1-2

60 bits

Single PMI

Mode 3-1

64 bits

Multi-PMI

Mode 2-2

38 bits

Wideband

No PMI

Mode 2-0

6 bits

Single PMI

Mode 2-1

11 bits

No PMI

Mode 1-0

4 bits

Single PMI

Mode 1-1

11 bits

Single or Multi-PMI = closed loop MIMO with PMI feedback

No PMI = Single antenna, TxDiv or OL MIMO

The maximum number of feedback bits for each option Assuming 20 MHz BW and 4*4 CL MIMO is listed excluding RI

- With Periodic reporting RI is sent in separate subframes with potentially larger periodicity

- In Aperiodic reporting The RI is separately coded with each CQI/PMI report

*See TS 36.213

cqiAperMode

Aperiodic CQI feedback mode

LNCEL; FBT1(0) – familly modes 2-x, FBT2(1)- familiy modes 3-x(x defined by MIMO algorithm internal in eNodeB); FBT2 (1)

RA41212EN10GLA1


44


Zadoff-Chu sequences• Zadoff-Chu sequences are used as

– UL demodulation and sounding reference signals– random access preamble sequence– DL primary synchronization signal

• ZC sequences are CAZAC (constant amplitude zero autocorrelation) sequences

– Low cubic metric and flat frequency response

• The elements of ZC sequence are points from unit circle• It is possible to create ZC sequences of any length with

relatively simple formulas• Depending on sequence length different number of base/root

sequences can be formed – Sequence with prime number of elements is optimal– Root sequence can be considered as circular. Different cyclic shifts of

a root sequence can be obtained by changing the starting element▪ Cyclic shift must be larger than time ambiguity of received sequence

RA41212EN10GLA1


45


UL DM RSCell A Cell B Cell C

freq

UE 1 UE 2

UE 3

Orthogonal DM RS

High cross-correlation

grpAssigPUSCHdefines the assigned PUSCH groupLNCEL; 0..29; 1; 0

ulRsCsDefines cyclic shift of UL RSLNCEL; 0..7; 1; 0

• The good cross correlation properties of ZC sequences are only applicable between sequences of the same length

– Cells of the same eNB may have coordination in scheduling but generally it can not be assumed that UL allocations in the neighboring cells are the same

• When UL allocations are not coordinated high cross correlations are possible between UEs in neighboring cells

• In order to average the cross correlations, DM RS sequences change between slots. Both root sequence and cyclic shift can change when group hopping/sequence hopping and cyclic shift hopping are used

RA41212EN10GLA1


46


Uplink Control Signaling: PUCCH vs. PUSCH

• PUCCH (Physical Uplink Control Channel)

– Used when the UE is not sending data simultaneously

– Shared frequency and time resource reserved exclusively for the UEs transmitting only L1/L2 control signals

– Optimized for large number of simultaneous UEs with relatively small number of control signaling bits per UE (1…11)

– Very high multiplexing capacity, spectral efficiency e.g.▪ 18 UEs/RB transmitting

ACK/NACK (PUCCH Format 1a/1b)

▪ 6 UEs/RB transmitting 11-bit CQI + 2-bit A/N (PUCCH Format 2b)

• PUSCH (Physical Uplink Shared Channel)

– Used when the UE transmits also data

– 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)

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

*TDM = Time Domain Multiplexing

RA41212EN10GLA1


47


PUCCH, basics

• PUCCH (from single-UE perspective)– Frequency resource of one RB

– Time resource of one sub-frame (A/N repetition is also supported)

• Slot based frequency hopping is always used– It provides the sufficient degree of frequency diversity

– Hopping takes place on the band edges, symmetrically over the center frequency

• Multiplexing between UEs– FDM btw RBs

– CDM inside the RB

slot

systembandwidth

Resource block

PUCCH

* FDM = Frequency Division Multiplexing

CDM = Code Division Multiplexing

A/N = ACK/NACK

RA41212EN10GLA1


48


PUCCH, UE Multiple Access Within a RB

• UEs are separated using of CDM (within an RB)

• Two orthogonal CDM techniques are applied on PUCCH – CDM using cyclic shifts of CAZAC* sequence

– CDM using block-wise spreading with the orthogonal cover sequence

• Multiplexing example: PUCCH Format 1/1a/1b (e.g., A/N)– Both CDM techniques are in use -> 18 parallel resources

*) The applied sequences are not true CAZAC but computer searched Zero-Autocorrelation (ZAC) sequences

RS RS RS

slot

SF=3

SF=4 Cyclic Orthogonal cover codeshift 0 1 2

0 0 121 62 1 133 74 2 145 86 3 157 98 4 169 10

10 5 1711 11

block-wise spreading

CDM inCS

domain

SF = 3 for Reference Signals and SF = 4 for ACK/NACKSF = Spreading Factor

deltaPucchShiftdelta cyclic shift for PUCCH formats 1/1a/1b LNCEL; 1..3; 1; 2 (i.e. 6 cyclic shifts)

*CDM = Code Division Multiplexing

RA41212EN10GLA1


49


PUCCH Formats

• Format 1/1a/1b– Length-12 CAZAC sequence modulation + block-wise

spreading -> 1 symbol (1 or 2 bits per slot)

• Format 2/2a/2b– Length-12 CAZAC sequence modulation (& no block-wise

spreading) -> 5 symbols per slot

PUCCH formats Control typePUCCH Format 1 Scheduling requestPUCCH Format 1a 1-bit ACK/NACKPUCCH Format 1b 2-bit ACK/NACKPUCCH Format 2 CQIPUCCH Format 2a CQI + 1-bit ACK/NACKPUCCH Format 2b CQI + 2-bit ACK/NACK

Number of Bits Multiplexing Capacity (UE/RB)ON/OFF keying 36, *18, 12

1 36, *18, 12 2 36, *18, 12

20 12, *6, 42122

12,* 6, 412, *6, 4

*typical value

RA41212EN10GLA1


50


Mapping of logical PUCCH resources into physical PUCCH resources

m=1 m=0m=3 m=2

m=2 m=3m=0 m=1

slot

systembandwidth PUCCH

• 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 resources are allocated explicitly via RRC

• Dynamic A/N is located at the innermost PUCCH RBs– Allocated implicitly based on PDCCH allocation

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)

-> dynamic allocation

nCqiRbreserved RBs for 2/2a/2bLNCEL; 1..98; 1; 2

RA41212EN10GLA1


51


Capacity of PUCCH resources

6 CS 6 UEs (12 CS 12 UEs) 10 msec period, 2 RB total 120 UEs (240)

6 CS & 3 cover codes 18 UEs 5 msec period, 2 RB total 180 UEs

Configuration example:

6 CS & 3 cover codes 18 Ues per subframe

Frame (10 msec)

RB (180 kHz)

PUSCH

1 UE – 1 RB per TTI

RA41212EN10GLA1


52


Control signaling on PUSCH (1/2)

• TDM multiplexing between control and data– Data and the different control fields (ACK/NAK, CQI/PMI) are mapped to

separate modulation symbols▪ Separate coding btw data and control▪ Separate coding btw different control fields

• Same gain factor for control and data

• Control modulation– CQI utilizes the same modulation as data– ACK/NACK is transmitted always using QPSK constellation

▪ Outermost constellation points are selected in the case of 16QAM/64QAM

MUX DFT IFFTCP

Data symbols

CQI symbols

ACK/NACK symbols

RA41212EN10GLA1


53


Control signaling on PUSCH (2/2)

• Time-first mapping for CQI▪ CQI resources are placed at the

beginning of the SC-FDMA Symbols

• ACK/NACK is placed at the end of the SC-FDMA symbols

RI+data AN+data DM RS AN+data RI+data RI+data AN+data DM RS AN+data RI+data

slot #1 slot #2

• Control and data multiplexing is performed in such that control is present on both slots of the subframe ( FH gain when available)

– ACK/NACK is placed next to RS (at maximum 2 blocks/slot for A/N)

– Rank indicator is placed next to the A/N (at maximum 2 blocks/slot for RI)

RS = Reference Signals

A/N = ACK/NACK

RA41212EN10GLA1


54


Sounding reference signalPRB sub-

framei i +11

1 13

5

7

9

11

13

15

17

19

21

23

25

27

29

31

33

35

37

39

41

43

45

47

49

PUSCH (scheduled) PUSCH (persistent)DM RSPUCCH

SRS

Cell specific SRS bandwidth

Transmission from one UE (example)

• SRS is used to assist frequency dependent scheduling

• Wide BW signal or frequency hopping/scanning can be used to obtain info about channel characteristics outside current PUSCH frequencies

• Zadoff-Chu sequences are used. UEs can be multiplexed to same resources by

– Interleaved FDMA (every other subcarrier is used by one UE)

– Different cyclic shifts

• SRS can also be used as reference for timing advance measurements. Low periodicity is sufficient in this case

NOT IN RL10

02 RA41212EN10GLA1 Channel Config

Documents

Transcript of 02 RA41212EN10GLA1 Channel Config