lte tutorial femto_forum_part1

1Marius Pesavento, Willem Mulder, Femto Forum Plenary, June 2010, Reading, UK © mimoOn

LTE Tutorial part 1LTE Basics

Marius Pesavento - [email protected] Mulder - [email protected]


Agenda

Part 1, LTE Basics 9:30 – 10:30 Introduction to LTE FDD/TDD frame structures and reference signals Physical channels, logical channels PHY signal processing architecture H-ARQ processing, H-ARQ timing UE categories

Part 2, Advanced topics in LTE 11:00 – 12:30 The LTE MIMO modes Codebook-based precoding Closed loop operation CQI reporting modes Using antenna port 5 (SDMA) techniques Simulation results Outlook LTE Advanced

Q & A 12:30 – 13:00


3G Evolution

HSPA evolution Gradually improved performance at low additional cost in 5MHz spectrum

allocation Next step: dual carrier allocation (10MHz)

LTE LTE is new Radio Access Network (RAN) significantly improved performance in up to 20MHz allocation Peak data rates up to 300Mbps

LTE-Advanced natural evolution of LTE, next major step toward IMT-Advanced support spectrum aggregation up to 100MHz and data rate up to 1Gbps

SPRING 2011


LTE Targets

Cell-capacity (Control plane): 200 user per cell in 5MHz Peak data rate

DL: 300MBit/s UL: 75 MBit/s

Control plane latency: 50/100ms (idle to active) User Plane Latency: <5ms (unload condition) Interworking with UMTS, WCDMA, GSM/EDGE Access technology:

OFDMA in DL SC-FDMA in UL (reduced PAPR)

Basis antenna configuration: eNB: Tx 1 to 4; Rx ≥ 1 UE: Tx = 1; Rx ≥ 2 (depending on UE category )


E-UTRA frequency bands

TDDN/A2400 MHz-2300 MHz2400 MHz-2300 MHz40

TDDN/A1920 MHz-1880 MHz1920 MHz-1880 MHz39

TDDN/A2620 MHz–2570 MHz2620 MHz–2570 MHz 38




TDDN/A2025 MHz–2010 MHz 2025 MHz –2010 MHz34

TDDN/A1920 MHz–1900 MHz1920 MHz–1900 MHz33

...

FDD20768 MHz–758 MHz798 MHz–788 MHz14

FDD21756 MHz–746 MHz787 MHz–777 MHz13

FDD[TBD][TBD]–[TBD][TBD]–[TBD]12

FDD23 MHz1500.9 MHz–1475.9MHz1452.9 MHz–1427.9MHz

11

FDD340 MHz 2170 MHz–2110 MHz1770 MHz–1710 MHz10

FDD60 MHz1879.9 MHz–1844.9MHz1784.9 MHz–1749.9MHz9

FDD10 MHz960 MHz–925 MHz915 MHz–880 MHz8



FDD20 MHz894MHz–869 MHz849 MHz–824 MHz5

FDD355 MHz2155 MHz–2110 MHz1755 MHz –1710 MHz4

FDD20 MHz1880 MHz–1805 MHz1785 MHz–1710 MHz 3

FDD20 MHz1990 MHz–1930 MHz1910 MHz–1850 MHz 2

FDD130 MHz2170 MHz–2110 MHz 1980 MHz–1920 MHz 1

FDL_low-FUL_highFDL_low – FDL_highFUL_low – FUL_high

Duplex Mode

UL-DL Band separation

Downlink (DL)eNode B transmit

UE receive

Uplink (UL)eNode B receive

UE transmit

E-UTRA Band

UMTS band

extension band


Basic Transmission Schemes

Transmission Bandwidth 1.4 MHz 3 MHz 5 MHz 10 MHz 15 MHz 20 MHz

Sampling Frequency 1.92 MHz 3.84 MHz 7.68 MHz 15.36

MHz23.04 MHz 30.72 MHz

FFT Size 128 256 512 1024 1536 2048

#RBs (12 subcarrier)

6 15 25 50 75100

(110)


Frame Structure Type 1

Frame Structure Type 1

frame structure type 1 is applicable to FDD (frequency division duplex), full-duplex and half-duplex

#0 #1 #2 #3 #18 #19

one slot, Tslot = 15360*TS = 0.5 ms

one radio frame, Tf = 307200*TS = 10 ms

one subframeTransmission Time Interval

(TTI)= 1ms

TS basic time unit corresponding to sampling frequency 30.72MHz


Slot Structure

normal cyclic prefix

extended cyclic prefix, ∆f = 15 KHz

normal cyclic prefix #2normal cyclic prefix #1

2048*TS144*TS 2048*TS2048*TS2048*TS2048*TS2048*TS2048*TS

160*TS 144*TS144*TS144*TS144*TS144*TS

slot

#0 #6

extended cyclic prefix

#0 #5

2048*TS512*TS2048*TS

512*TS2048*TS512*TS2048*TS

512*TS2048*TS512*TS2048*TS

512*TS

slot


subframe 1 ms


Frame Structure Type 2: TDD

DL#0

S#1

UL#2

UL/DL#3

UL/DL#4

S/DL#6

DL#5

UL/DL#7

UL/DL#8

UL/DL#9

Downlinksubframe

Uplinksubframe

Special guardsubframe for

DL to UL switch

Special guardsubframe orDownlink SF

Uplink orDownlinksubframe

special subframe: DL to UL switching

S#1 or #6

DwPTSGP UpPTS

DwPTS: DL pilot time slotshortend DL subframe

(3,8,9,10,11, or 12 OFDM symbols) reference signals, primary sync and control, PDSCH

GP: Guard period(1,2,3,4,7,8,9,10 OFDM symbols)

UpPTS: UL pilot time slot(1 or 2 OFDM symbols)

sounding reference or RACH

SS

SR

S a

ndC

ontro

lP

SS

0 1 2


Frame Structure Type 2: TDD

Tx

Rx

Tx

Rx

DL UL Tx#2

UL Tx#3G

P

UpP

TS

Dw

PTS

DL UL Rx#2

UL Rx#3G

P

UpP

TS

Dw

PTS

DL Tx#0

DL Tx#4

DL Tx#6

DL Tx#5G

P

UpP

TS

Dw

PTS

DL DL Rx#4

DL Rx#6

DL Rx#5G

P

UpP

TS

Dw

PTS

pathdelay

pathdelay

UL/DL switching must be accomplished within the CP length

(e.g. if path delay is zero)


DwPTS, GP, UpPTS length(in OFDM symbols)

FormatNormal CP Extended CP

DwPTS GP UpPTS DwPTS GP UpPTS

0 3 10

1

38

666.7µs 200Km

11 9 4 8 3

2 10 3 9 2

3 11 2 10 1

4 12 1 3 7

25 3 9

2

8 2

6 9 3 9 1

7 10 2 - - -

8 11 1 - - -


Resource Blocks

7 OFDM symbols

12 subcarriers

frame structure 1

normal cyclic prefix

∆f = 15 KHz

DC

1DL

RB −Nresource block

resource block 0

all subframes


Physical ChannelsDownlink (DL)

Physical Broadcast Channel (PBCH) System Information (Master Information Block

MIB) approx. every 40 ms Physical Downlink Control Channel (PDCCH)

DL Control Information Format (DCI-format), DL-grants (current TTI), UL-grants (+4 TTI), uplink power control

Physical DL Shared Channel (PDSCH) DL transport blocks (TBs), DL Control Information,

System Information Block (SIB), Paging Channel (PCH), Multicast Channel (MCH)

Physical Control Format Indicator Channel (PCFICH) location of the PDCCH

Physical Hybrid ARQ Indicator Channel (PHICH) UL ACK/NACK

Physical Multicast Channel (PMCH)


Physical ChannelsUplink (UL)

Physical Random Access Channel (PRACH) UL timing estimation (path delay), UL

scheduling request (SR) Physical Uplink Control Channel (PUCCH) Channel Quality Indicater (CQI),

Precoding Matrix Indicator (PMI), Rank Indicator (RI), ACK/NACK, SR

Physical Uplink Shared Channel (PUSCH) UL TBs, ACK/NACK, CQI, PMI, RI, SR


PHY Signals

Downlink Primary and Secondary Synchronization Signal

cell-search, DL-frame synchronization, time, frequency, drift,

Cell-specific reference signals (antenna port 0 - 3), orthogonal (non-overlapping) in time-frequency-domain MIMO channel estimation, fine frequency estimation, UL-CQI

estimation

UE-specific reference signals implicit signaling of DL-transmit beamforming weights

Uplink Demodulaton Reference Signal Sounding Reference Signal

UL wideband CQI estimation

Random-Access Sequence for UL timing synchronization


one antenna port(frame structure 1,

normal cyclic prefix)

reference signal 0

two antenna ports(frame structure 1,


reference signal 0

reference signal 1

not used for transmissionon this antenna port

slot slot slot

Cell-Specific Reference Signals

carrier frequency: 2.6GHzLTE requirement

max speed: 350km/hmax Doppler frequency: 843Hz

Clarke's modelcoherence time: T > 9/(16π fm)

approx. 3 OFDM symbols

pilot spacing in frequencycoherence bandwidth B ≥ 6x15KHz

B ¼ 1 / (2 π τ) ⇒delay spead τ :

τ ¼ 1 / (2 π B) =1.77µsec (¼ 54 smpls; corresp. to 531 meter )

Port 0 Port 1

Port 0Tx

Tx


reference signal 0

reference signal 1

not used for transmissionon this antenna port

reference signal 2

reference signal 3

four antenna ports(frame structure 1,


slot slot even slot odd slot even slot odd slot

Cell-Specific Reference Signals

Port 3

Port 2

Port 1

Port 0Tx


DL time-frequency structure

•DL payload on DL Shared Channel•Primary synchronization signal •Secondary synchronization signal•Broadcast Channel•DL Control Channel•Reference signal

20MHz 30.72MHz

guard band


UL time-frequency structure

demodulation reference

signal (DRS)

soundingreference

signal (SRS)

PUSCH

PUCCH

time / OFDM symbol number

frequ

ency


MAC PDU

CB

Seg

-m

enta

tion

Mod

ulat

ion

Layer Mapping

MIMO Precoding

P/S Sync Signals

RefSignal

Frame Builder

IFFT CP Adding

Pulse Shape

Cha

nnel

Cod

ing

Turb

o

HARQ Support& Rate Matching

•HARQ hard buffer for S1, P1, P2

• Subblock interleaver•Rate Matcher, RVs Sc

ram

blin

g

to DACs

TB C

RC

CB

CR

C

CB

C

onca

tena

tion

PDSCH Tx

num

bero

fan

tenn

as

number ofTransport Blocks (TBs)

number ofstreams


MAC PDU

frame/RBdemapper

RotatorFreq. Off.

CP Removal FFT

Channel Estimation

Measure-ments

MIMO Detector

FromADCs

Layer Demapper

P/S-Sync Processing

CB

Con

cate

-na

tion

Soft

Dem

odul

ator

8

bit

Turb

oD

ecod

er

HARQ Support & Rate Matching:

•HARQ soft buffer for S1, P1, P2,

•Subblock interleaver•Soft-Combiner 8 bit, RVs D

escr

ambl

ing

TB C

RC

CB

CR

C

CB

sem

enta

tion:

tran

sitio

n fr

om

OFD

M w

ise

to

CB

-wis

e pr

oces

sing

antenna ports

Down-sampling

filter

Fine Frequency estimation

RotatorSamp.D. other CWs

smple drift

PDSCH Rx


Transform Precoding

Mixed-Radix DFT

Demod. Ref.

Signal

RBResource Mapper

IFFT CPAdding

Pulse Shape DAC

RotatorFreq. Cor.

MAC PDU

CB

Seg

-m

enta

tion

Mod

ulat

ion

Cha

nnel

Turb

o C

odin

g

Dat

a &

Con

trol

M

ux

Scra

mbl

ing

TB C

RC

CB

CR

C

CB

C

onca

tena

tionHARQ Support

& Rate Matching•HARQ hard buffer for S1,

P1, P2• Subblock interleaver

•Rate Matcher, RVs

RotatorSamp.

Drift

Sound. Ref.

Signal

controlTS36.212Figure

5.2.2-1

Cha

nnel

Inte

rleav

ing

ACK RI

Length 32 block code

CQI and/or PMI reportCQI <= 11 bit

CQI and/or PMI report

CQI > 11 bit

32bit

Cha

nnel

Con

v.

Cod

ing

CB

CR

CRate Matching

PUSCH Tx

number of Transport Blocks (TBs) of different users

to reduce PAPR


controlTS36.212Figure

5.2.2-1

MAC PDU

CB

Con

cate

-na

tion

Soft

dem

odul

ator

8.bi

t

Turb

oD

ecod

er

Des

cram

blin

g

TB C

RC

CB

CR

C

CB

Seg

men

tatio

n:Tr

ansi

tion

from

O

FDM

-to

CB

-wis

e pr

oces

sing

Tranform (De)Precoding(mixed-Radix

DFT)

frame/RB Demapper

CP Removal FFT

Demod. Ref.Channel Estimation

Measure-ments

Multi-AntennaReceiver

Sounding Ref.Processing

Dat

a &

Con

trol

D

emux

Frame timing

HARQ Support & Rate Matching:

•HARQ soft buffer for S1, P1, P2,

•Subblock interleaver•Soft-Combiner 8 bit, RVs

FromADCs

Cha

nnel

de

inte

rleav

er

ACK RIBlock decoder(32,11)

Rate DeMatching:•Subblock interleaver

•Soft-Combiner 8 bit, RVsViterbiCB CRC

PUSCH Rx


Downlink Control Indicator Format (DCI format)

DCI format 0 is used for the transmission of UL-SCH assignments DCI format 1 is used for the transmission of DL-SCH assignments

for single antenna operation DCI format 1A is used for a compact transmission of DL-SCH

assignments for single antenna operation DCI format 1B is used to support closed-loop single-rank

transmission with possibly contiguous resource allocation DCI format 1C is for downlink transmission of paging, RACH

response and dynamic BCCH scheduling DCI format 2 is used for the transmission of DL-SCH assignments

for MIMO operation DCI format 3 is used for the transmission of TPC commands for

PUCCH and PUSCH with 2-bit power adjustments DCI format 3A is used for the transmission of TPC commands for

PUCCH and PUSCH with single bit power adjustments


CRC scramblingwith RNTI /(UE Tx port)

specific

CRCgeneration

L=16

DCI tail bit convolutional

encoder, rate 1/3

interleaver,rate-matching

PDCCHmultiplexing <NIL>element

insertion

cell-specificscrambling

other DCIs

QPSKmodulation

sub-block interleaver(on quadruples of modulated symbols), remove <NULL>

elements

Resource Mapper,(mapping to RE groups)

time first – then frequency

layer mapping,pre-coding:

single antenna port or transmit

diversity

antenna ports 0,...,3

other DL channels

IFFT andCP attachment

MIMOchannel

FFT andCP removal,

frequency and timing correction

Resource demapper(1-3 OFDM symbols,

according to CFI)

sub-block de-inter-leaver

equalizer, MIMO detector,

(requires channel estimation)

soft-demodulator

rate-dematching,

deinterleaving

Viterbi decoder

cell specific de-

scrambling

44 blind decoding attempts (common-

and UE-specific-search-space),

44 PDCCHcandidates

code bit extractionCRC calculation

XOR

CRC extraction

RNTIskip some decodes if RNTI is found

PDCCH processing chain

RNTI: radio network temporary identifier

DCI

User specific search space

(aggregation level)1-CCE (2x6attempts)2-CCE (2x6attempts)4-CCE (2x2attempts),8-CCE (2x2attempts)

Cell specific search space

(aggregation level)4-CCE (2x4attempts)8-CCE (2x2attempts)


spreading with

sequence

Schedulingrequest (SR)(presence/absence)

Block codeLength 20

never simultaneously with PUSCH

CQI, PMI,RI report (2)<= 4bit

ACK/NACK (1a,1b)1 or 2 bit

to map on CQI resourceconcatenation:

•only CQI (2: 20 bit)•CQI + ACK/NACK

(2a: 21 bit, 2b: 22bit)

to map on SR resource•w/o ACK/NACK (1);d(0)=1

•w ACK/NACKd(0) = 1,-1d(0) = 1,j,-1,-j

to map on ACK/NACK resourceACK/NACK w/o CQI or SR, 1a: d(0)= 1,-11b: d(0)= 1,j,-1,-j

20bit

formapping to outerRBs

formapping to inRBs

Pseudo-Randomsequence generator

cellIDinit Nc =

(2)RBN

(1)csN

),(cellcs lnn s

)()(, nr vuα

12PUCCHseq =N

spreading with

orthogonalsequence

12 s

ymbol

s

)(oc

iwn

4PUCCHSF =N

UE specificcell specific

scrambling

spreading with

sequence

)()(, nr vuα

12PUCCHseq =N

modulation:d(0),…d(19)

on QPSK (BPSK)

36.211, 7.1d(20), d(21)according to

36.211, Table 5.4.2-1

resource index (2)PUCCHn

determines cyclic shift α

Resourcemapper

(k,l,slot#)

IFFT

CP attach

include demodulationreference signals for format 1 (see below)

(1)PUCCHnresource index

determines cyclic shiftand orthogonal sequence

12 s

ymbol

s

include demodulationreference signals for format 2 (see below)

“d”

“z”

PUCCH processing chain Txall formats


Resource de-mapper(k,l,slot#)

form

at 2

,2a,

2b

(CQ

I,PM

I,RI)

CP removal

FFT (2048)

format 1,1a,1bACK/NCK w or w/o SR(see next page)

multiplication with

conjugate of

)()(, nr vuα

12PUCCHseq =N



IDFT

leng

th 1

2 separateusers

accordingto cyclic shift in time-

domain

multiplication with

conjugate of

)()(, nr vuα

12PUCCHseq =N



IDFT

leng

th 1

2 channel estimation

separate users accordingto cyclic shift in time-

domain

tap M(<12) channelcoefficient vector

M depends on numberof shifts in use

matched filtering

withtap Mcoef.

vector

user m

user m

hard

dem

odul

ator


descrambling

segmentation

SR•w/o ACK/NACK (1);d(0)=1

•w ACK/NACKd(0) = 1,-1

d(0) = 1,j,-1,-j

ACK/NACK(1a,1b)

Block decoding(bit-level matched

filter)

CQI, PMI,RI report (2)

QPSK

PUCCH processing Rxformat 2, 2a, 2b



on SRresource

form

at 1

,1a,

1b

(SR a

nd A

CK/N

ACK)

CP removal

FFT (2048)

format 2,2a,2b(CQI,PMI,RI)

multiplication with

conjugate of

)()(, nr vuα

12PUCCHseq =N



IDFT

leng

th 1

2 separateusers


domain

multiplication with

conjugate of

)()(, nr vuα

12PUCCHseq =N



IDFT

leng

th 1

2channel

estimation 1

separate users according to cyclic shift in time-domain

tap M(<12) channel

coefficient vector

M depends onnumber of

shifts in use

matched filtering

withtap Mcoef.

vector

user m

user m

hard

dem

odul

ator


descrambling

ACK/NACK

chan

nel e

stim

atio

n2se

para

te u

sers

acc

ordi

ng to

orth

ogon

al

cove

r seq

uenc

e (d

espr

eadi

ng)

desp

read

ing

sepa

rate

use

re a

ccor

ding

to

orth

ogon

al s

eque

nce

SR

PUCCH processing Rxformat 1



on ACK/NACK

resource

form

at 1

,1a,

1b

(SR a

nd A

CK/N

ACK)

CP removal

FFT (2048)

format 2,2a,2b(CQI,PMI,RI)

multiplication with

conjugate of

)()(, nr vuα

12PUCCHseq =N



IDFT

leng

th 1

2 separateusers


domain

multiplication with

conjugate of

)()(, nr vuα

12PUCCHseq =N



IDFT

leng

th 1

2channel

estimation 1

separate users according to cyclic shift in time-domain

tap M(<12) channel

coefficient vector

M depends onnumber of

shifts in use

matched filtering

withtap Mcoef.

vector

user m

user m

hard

dem

odul

ator


descrambling

ACK/NACK

chan

nel e

stim

atio

n2se

para

te u

sers

acc

ordi

ng to

orth

ogon

al

cove

r seq

uenc

e (d

espr

eadi

ng)

desp

read

ing

sepa

rate

use

re a

ccor

ding

to

orth

ogon

al s

eque

nce

PUCCH processing Rxformat 1a, 1b


spreading with

sequence

formapping to outerRBs

formapping to inRBs

Pseudo-Randomsequence generator

cellIDinit Nc =

(2)RBN

(1)csN

),(cellcs lnn s

)()(, nr vuα

12PUCCHseq =N

spreading with

orthogonalsequence

12 s

ymbol

s

)(oc

iwn

4PUCCHSF =N


scrambling

spreading with

sequence

)()(, nr vuα

12PUCCHseq =N

modulation:d(0),…d(19)

on QPSK36.211, 7.1d(20), d(21)according to

36.211, Table 5.4.2-1



Resourcemapper

(k,l,slot#)

IFFT

CP attach

(1)PUCCHnresource index

determines cyclic shiftand orthogonal sequence

12 s

ymbol

s

input sequence for format 1

input sequence for format 2

Demodulation reference signals for PUCCH format 2


3 xrepetition

ACK/NACK1 bit

BPSK(I or Q)

symbol levelSpreading,

length 4 orthogonal sequence

3bit

super-positionof different

ACK/NACKS

3 symbols 12 symbols

resource mapper,PHICH group is

mapped to 3 groups of 4 REs

scrambling

12 s

ymbol

s

layer mapperSISO or MIMO TD

FFT / CP insertion

MIMOchannel

CP removal/IFFT

resource demapperMIMO detectordescrambling

matched filterlength(12)

ACK/NACK1 bit

other ACK/NACK1 bit

other ACK/NACK1 bit

Location depends on the index of the first RB of the corresponding PUSCH transmission

PHICH(DL HARQ)

Max. 8 different sequences

Selection depends on the index of the first RB of the corresponding PUSCH transmission


MIB

cell specificscrambling scrambling

tail bit convolutional

encoder, rate 1/3

QPSK modulation

layer mapping forsingle antenna or transmit diversity

precodingSFD

resourcemapping

IFFTCP inclusion

MIMOchannel

CP removelFFT

Equalization(SISO, MISO, or TD)

soft demodulator

(QPSK)

channel estimates

Viterbi decoder

interleaver,rate-matching

rate matching buffer

CRC attachCRC mask

code bit extraction, CRC

computationantenna config

CRC extaction

XOR

antenna config

frame no 0,1,2,3

PBCH

PBCH carries important PHY information:system bandwidth, number of transmit antennas, PHICH configuration and system frame number,…

maskedCRC

mask

MIB

After successful reception of PBCH, UE can read D-BCH in

PDSCH (including PCFICH and PDCCH) which carries system

information not including in PBCH


possible cell specificroot-sequences,(conjugate)

RACH sequence extends over several slots

CP inclusion(3168, 21024,

6240)

add to OFDM frame in time

domain

UL Tx signal in time domain:PUSCH, PUCCH,DRS,SRS,including CP

Channelphase rotation,

(mixing,frequency shift to DC)

decimation1/24

LP filter1/24DFT 1024Multiplication

IDFT 1024(results in change of

sampling rate)

Peak dection,path delay estimation

RACH sequence, associated timing-advance

RACH sequence, associated timing-advance

Zadoff-Chu sequence (L=839), selectec from set of 64 sequences),different root-sequences or different cyclic shifts, Create in 839 sequence in frequency domain

Zero padding to 1024

IDFT of length 1024

Upsampling by 24,

LP filtering

Rotator, frequency

shift

PRACH

correlation (convolution) in time domainreplaced by multiplication in frequency domain


PCFICHDL Control Format

block codeL=16

2 bits scamblingcell and

subframe dependent

modulatorQPSK

layer mapping

FFT / CP insertion

power boosting

power control

MIMOchannel

resourcemapper

(4 blocks of 4REs = 1RE

group)

cell ID

precodingSISO or

Tx diversity

CP removalII

FFT

resource demap

MIMO detectiondemodulatordescramblingblock

detection

number ofOFDM symbolsreserve for control1,2,3


Rate matching and HARQ processing

systematicparity 1parity 2

sub-blockinterleaver

column permutation

write-in row-wise

read-out column-wise S1

P1P2

MUX

S1

P1/P2

RV0

RV2

RV3

RV1


HARQ timing


UE Categories synchronous HARQ in UL, ACK/NACK in 4 TTI after UL reception,

re-transmission (UL) in 8 TTI after initial transmission, total of 8 HARQ processes asynchronous HARQ in DL, ACK/NACK in 4 TTI after DL reception, retransmission

with DL scheduling grant, total number of 8 HARQ processes

Downlink physical layer parameter values set by UE Category

UE CategoryMaximum number of DL-SCH transport block bits received

within a TTI

Maximum number of bits of a DL-SCH transport

block received within a TTI

Total number of soft

channel bits

Maximum number of supported layers for

spatial multiplexing in DL

Category 1 10296 10296 250368 1

Category 2 51024 51024 1237248 2

Category 3 102048 75376 1237248 2

Category 4 150752 75376 1827072 2

Category 5 302752 151376 3667200 4

Uplink physical layer parameter values set by UE Category

UE Category

Maximum number of bits of an UL-SCH transport block transmitted within a TTI

Support for 64QAM in UL

Category 1 5160 No

Category 2 25456 No

Category 3 51024 No

Category 4 51024 No

Category 5 75376 Yes

≈ 8HARQ bufferx(3(S1,P1,P2)x10296+

12(termination))


UE Categories


TDD: DL grants and ACK/NACK reporting

FDD: only one DL (and one UL) grant per TTI. Corresponding DL TBs need to be ACK/NACK 4 TTIs after reception (1 or 2 bits).

TDD: ACK/NACK required for detected PDSCH and for DL SPS release on PDCCH.

TDD: usually one DL grant (but up to 2 DL grants, in special case of UL-DL config. 0) can be received within one TTI.


subframe 1 ms


TDD ACK/NACKRecall: Frame Structure Type 2: TDD

DL#0

S#1

UL#2

UL/DL#3

UL/DL#4

S/DL#6

DL#5

UL/DL#7

UL/DL#8

UL/DL#9

Downlinksubframe

Uplinksubframe

Special guardsubframe for

DL to UL switch

Special guardsubframe orDownlink SF

Uplink orDownlinksubframe

special subframe: DL to UL switching

S#1 or #6

DwPTSGP UpPTS

DwPTS: DL pilot time slotshortend DL subframe

(3,8,9,10,11, or 12 OFDM symbols) reference signals, primary sync and control, PDSCH

GP: Guard period(1,2,3,4,7,8,9,10 OFDM symbols)

UpPTS: UL pilot time slot(1 or 2 OFDM symbols)

sounding reference or RACH

SS

SR

S a

ndC

ontro

lP

SS

0 1 2


TDD: UE ACK/NACK procedure(PUSCH transmission and PHICH reception)

TDD UL/DLConfiguration

subframe number i

0 1 2 3 4 5 6 7 8 9

0 6,7 4 6,7 4

1 4 6 4 6

2 6 6

3 6 6 6

4 6 6

5 6

6 6 4 7 4 6

•ACK/NACK received on PHICHin subframe i•for UL transmission in subframe i - k,where the values for k are given inthe table.

k for TDD configurartion 0-6

TDD UL/DLConfiguration

subframe number i

0 1 2 3 4 5 6 7 8 9

0 4 7 6 4 7 6

1 4 6 4 6

2 6 6

3 6 6 6

4 6 6

5 6

6 4 6 6 4 7

UE Rx Perspective•for UL transmission in subframe i,•ACK/NACK received on PHICH in subframe i + k, where the values for k are given inthe table.


UE Tx Perspective


DL control issues in TDD DL HARQ

TDD UL/DLConfig.

DL subframe number n

0 1 2 3 4 5 6 7 8 9

0 4 6 4 6

1 7 6 4 7 6 4

2 7 6 4 8 7 6 4 8

3 4 11 7 6 6 5 5

4 12 11 8 7 7 6 5 4

5 12 11 9 8 7 6 5 4 13

6 7 7 7 7 5

•reception of PDSCH in subframe n•ACK/NACK on PUSCH or PUCCH in subframe n + k


TDD UL/DLConfig.


0 1 2 3 4 5 6 7 8 9

0 6 4 6 4

1 7,6 4 7,6 4

2 8,7,4,6 8,7,4,6

3 7,6,11 6,5 5,4

4 12,8,7,11 6,5,4,7

5 13,12,9,8,7,5,4,11

6 7 7 5 7 7

•ACK/NACK on PUSCH or PUCCH in subframe n•for reception of PDSCH insubframe n - k


UE Rx Perspective UE Tx Perspective

Multiple ACK/NACK in one subframe:Requieres ACK/NACK bundling (logical AND of codewords) or ACK/NACK multiplexing.


TDD: Downlink Assignment Index DAIto prevent ACK/NACK errors due to bundling

k‘ for TDD configurartion 0-6 and DAI in DCI format 0 (UL assignments)

•DAI indicates the number of subframes with PDSCH receptions and SPS releases detected within n-k and n (k 2 K) that need to be bundeled in the UL ACK/NACK signaling.•DAI is used only for TDD

TDD UL/DLConfig.


0 1 2 3 4 5 6 7 8 9

0 DAI 6 4 DAI 6 4

1 DAI 6 4 DAI DAI 6 4 DAI

2 4 DAI 4 DAI

3 DAI 4 4 4 DAI DAI

4 4 4 DAI DAI

5 4 DAI

6 DAI DAI 7 7 5 DAI DAI 7 7 DAI

TDD UL/DLConfig.


0 1 2 3 4 5 6 7 8 9

0 DAI DAI 6 4 DAI DAI 6 4

1 DAI 7,6 4 DAI DAI 7,6 4 DAI

2 8,7,4,6 DAI 8,7,4,6 DAI

3 DAI 7,6,11 6,5 5,4 DAI DAI

4 12,8,7,11 6,5,4,7 DAI DAI

5 13,12,9,8,7,5,4,11 DAI

6 DAI DAI 7 7 5 DAI DAI 7 7 DAI

k for TDD configurartion 0-6 and DAI in DCI formats 1/1A/1B/1D/2/2A (DL)

0 or 4 or 841,1

3 or 731,0

2 or 620,1

1 or 5 or 910,0

Number of subframes with PDSCH transmission

DAIMSB, LSB

ULDAIV DL

DAIVor


End of Part 1

Thank you!!!


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lte tutorial femto_forum_part1

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