LTE Basics

1Marius Pesavento, Willem Mulder, Femto Forum Plenary, June 2010, Reading, UK © mimoOn
LTE Tutorial part 1
LTE Basics
Marius Pesavento - marius.pesavento@mimoOn.de
Willem Mulder - willem.mulder@mimoOn.de

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 MHz38
...
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–1427.9MH
z
11
FDD340 MHz2170 MHz–2110 MHz1770 MHz–1710 MHz10
FDD60 MHz1879.9 MHz–1844.9MHz1784.9 MHz–1749.9MHz9
FDD20 MHz894MHz–869 MHz849 MHz–824 MHz5
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
MHz
23.04
MHz
30.72 MHz
FFT Size 128 256 512 1024 1536 2048
#RBs
(12 subcarrier)
6 15 25 50 75
100
(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 subframe
Transmission 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*TS
144*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*TS
512*TS
2048*TS
512*TS
2048*TS
512*TS
2048*TS
512*TS
2048*TS
512*TS
2048*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
Downlink
subframe
Uplink
subframe
Special guard
subframe for
DL to UL switch
Special guard
subframe or
Downlink SF
Uplink or
Downlink
subframe
special subframe:
DL to UL switching
S
#1 or #6
DwPTS
GP UpPTS
DwPTS: DL pilot time slot
shortend 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
SSS
RSand
Control
PSS
0 1 2

Frame Structure Type 2: TDD
Tx
Rx
Tx
Rx
DL
UL Tx
#2
UL Tx
#3
GP
UpPTS
DwPTS
DL
UL Rx
#2
UL Rx
#3
GP
UpPTS
DwPTS
DL Tx
#0
DL Tx
#4
DL Tx
#6
DL Tx
#5
GP
UpPTS
DwPTS
DL
DL Rx
#4
DL Rx
#6
DL Rx
#5
GP
UpPTS
DwPTS
path
delay
path
delay
UL/DL switching
must be accomplished
within the CP length
(e.g. if path delay is zero)

DwPTS, GP, UpPTS length
(in OFDM symbols)
Format
Normal CP Extended CP
DwPTS GP UpPTS DwPTS GP UpPTS
0 3 10
1
3
8
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
1
DL
RB
−N
resource block
resource block 0
all subframes

Physical Channels
Downlink (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 Channels
Uplink (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 transmission
on this antenna port
slot slot slot
Cell-Specific Reference Signals
carrier frequency: 2.6GHz
LTE requirement
max speed: 350km/h
max Doppler frequency: 843Hz
Clarke's model
coherence time: T > 9/(16π fm)
approx. 3 OFDM symbols
pilot spacing in frequency
coherence 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 0
Tx
Tx

reference signal 0
reference signal 1
not used for transmission
on 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 0
Tx

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)
sounding
reference
signal (SRS)
PUSCH
PUCCH
time / OFDM symbol number
frequency

MAC
PDU
CBSeg-
mentation
Modulation
Layer
Mapping
MIMO
Precoding
P/S Sync
Signals
Ref
Signal
Frame
Builder
IFFT
CP
Adding
Pulse
Shape
ChannelCoding
Turbo
HARQ Support
& Rate Matching
•HARQ hard buffer for S1,
P1, P2
• Subblock interleaver
•Rate Matcher, RVs
Scrambling
to
DACs
TBCRC
CBCRC
CB
Concatenation
PDSCH Tx
numberof
antennas
number of
Transport Blocks (TBs)
number of
streams

MAC
PDU
frame/RB
demapper
Rotator
Freq. Off.
CP
Removal
FFT
Channel
Estimation
Measure-
ments
MIMO Detector
From
ADCs
Layer
Demapper
P/S-Sync
Processing
CBConcate-
nation
Soft
Demodulator
8bit
Turbo
Decoder
HARQ Support & Rate
Matching:
•HARQ soft buffer for S1, P1,
P2,
•Subblock interleaver
•Soft-Combiner 8 bit, RVs
Descrambling
TBCRC
CBCRC
CBsementation:
transitionfrom
OFDMwiseto
CB-wise
processing
antenna ports
Down-
sampling
filter
Fine
Frequency
estimation
Rotator
Samp.D. other CWs
smple drift
PDSCH Rx

Transform
Precoding
Mixed-Radix DFT
Demod.
Ref.
Signal
RB
Resource
Mapper
IFFT
CP
Adding
Pulse
Shape DAC
Rotator
Freq.
Cor.
MAC
PDU
CBSeg-
mentation
Modulation
Channel
TurboCoding
Data&Control
Mux
Scrambling
TBCRC
CBCRC
CB
Concatenation
HARQ Support
& Rate Matching
•HARQ hard buffer for S1,
P1, P2
• Subblock interleaver
•Rate Matcher, RVs
Rotator
Samp.
Drift
Sound.
Ref.
Signal
control
TS36.212Figure
5.2.2-1
Channel
Interleaving
ACK RI
Length 32
block code
CQI and/or PMI report
CQI <= 11 bit
CQI and/or
PMI report
CQI > 11 bit
32bit
Channel
Conv.
Coding
CBCRC
Rate Matching
PUSCH Tx
number of Transport Blocks (TBs)
of different users
to reduce PAPR

control
TS36.212Figure
5.2.2-1
MAC
PDU
CBConcate-
nation
Soft
demodulator
8.bit
Turbo
Decoder
Descrambling
TBCRC
CBCRC
CBSegmentation:
Transitionfrom
OFDM-toCB-wise
processing
Tranform
(De)Precoding
(mixed-Radix
DFT)
frame/RB
Demapper
CP
Removal
FFT
Demod. Ref.
Channel Estimation
Measure-
ments
Multi-
Antenna
Receiver
Sounding Ref.
Processing
Data&Control
Demux
Frame
timing
HARQ Support & Rate
Matching:
•HARQ soft buffer for S1, P1,
P2,
From
ADCs
Channel
deinterleaver
ACK RI
Block decoder
(32,11)
Rate DeMatching:
ViterbiCB 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 scrambling
with RNTI /
(UE Tx port)
specific
CRC
generation
L=16
DCI tail bit
convolutional
encoder, rate 1/3
interleaver,
rate-matching
PDCCH
multiplexing <NIL>element
insertion
cell-specific
scrambling
other DCIs
QPSK
modulation
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 and
CP attachment
MIMO
channel
FFT and
CP 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 PDCCH
candidates
code bit extraction
CRC calculation
XOR
CRC extraction
RNTI
skip 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
Scheduling
request (SR)
(presence/absence)
Block code
Length 20
never simultaneously with PUSCH
CQI, PMI,
RI report (2)
<= 4bit
ACK/NACK (1a,1b)
1 or 2 bit
to map on CQI resource
concatenation:
•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/NACK
d(0) = 1,-1
d(0) = 1,j,-1,-j
to map on ACK/NACK resource
ACK/NACK w/o CQI or SR,
1a: d(0)= 1,-1
1b: d(0)= 1,j,-1,-j
20bit
for
mapping
to outer
RBs
for
mapping
to in
RBs
Pseudo-Random
sequence generator
cell
IDinit Nc =
(2)
RBN
(1)
csN
),(cell
cs lnn s
)()(
, nr vu
α
12PUCCH
seq =N
spreading
with
orthogonal
sequence
12symbols
)(oc
iwn
4PUCCH
SF =N
UE specific
cell specific
scrambling
spreading
with
sequence
)()(
, nr vu
α
12PUCCH
seq =N
modulation:
d(0),…d(19)
on QPSK
(BPSK)
36.211, 7.1
d(20), d(21)
according to
36.211, Table
5.4.2-1
resource index (2)
PUCCHn
determines cyclic shiftα
Resourcem
apper
(k,l,slot#)
IFFT
CP attach
include demodulation
reference signals for
format 1 (see below)
(1)
PUCCHnresource index
determines cyclic shift
and orthogonal sequence
12symbols
include demodulation
reference signals for
format 2 (see below)
“d”
“z”
PUCCH processing chain Tx
all formats

Resource
de-mapper
(k,l,slot#)
format2,2a,2b
(CQI,PMI,RI)
CP
removal
FFT (2048)
format 1,1a,1b
ACK/NCK w or w/o SR
(see next page)
multiplication
with
conjugate of
)()(
, nr vu
α
12PUCCH
seq =N
resource index (2)
PUCCHn
IDFTlength12
separate
users
according
to cyclic
shift in
time-
domain
multiplication
with
conjugate of
)()(
, nr vu
α
12PUCCH
seq =N
resource index (2)
PUCCHn
IDFTlength12 channel estimation
separate users according
to cyclic shift in time-
domain
tap M(<12) channel
coefficient vector
M depends on number
of shifts in use
matched
filtering
with
tap M
coef.
vector
user m
user m
harddemodulator
UE specific
cell specific
descrambling
segmentation
SR
•w/o ACK/NACK (1);d(0)=1
•w ACK/NACK
d(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 Rx
format 2, 2a, 2b

Resource
de-mapper
(k,l,slot#)
on SR
resource
format1,1a,1b
(SRandACK/NACK)
CP
removal
FFT (2048)
format 2,2a,2b
(CQI,PMI,RI)
multiplication
with
conjugate of
)()(
, nr vu
α
12PUCCH
seq =N
resource index (2)
PUCCHn
IDFTlength12
separate
users
according
to cyclic
shift in
time-
domain
multiplication
with
conjugate of
)()(
, nr vu
α
12PUCCH
seq =N
resource index (2)
PUCCHn
IDFTlength12
channel
estimation 1
separate users
according to
cyclic shift in
time-domain
tap M(<12)
channel
coefficient vector
M depends on
number of
shifts in use
matched
filtering
with
tap M
coef.
vector
user m
user m
harddemodulator
UE specific
cell specific
descrambling
ACK/NACK
channelestimation2
separateusersaccordingtoorthogonal
coversequence(despreading)
despreading
separateusereaccordingto
orthogonalsequence
SR
PUCCH processing Rx
format 1

Resource
de-mapper
(k,l,slot#)
on
ACK/NACK
resource
format1,1a,1b
(SRandACK/NACK)
CP
removal
FFT (2048)
format 2,2a,2b
(CQI,PMI,RI)
multiplication
with
conjugate of
)()(
, nr vu
α
12PUCCH
seq =N
resource index (2)
PUCCHn
IDFTlength12
separate
users
according
to cyclic
shift in
time-
domain
multiplication
with
conjugate of
)()(
, nr vu
α
12PUCCH
seq =N
resource index (2)
PUCCHn
IDFTlength12 channel
estimation 1
separate users
according to
cyclic shift in
time-domain
tap M(<12)
channel
coefficient vector
M depends on
number of
shifts in use
matched
filtering
with
tap M
coef.
vector
user m
user m
harddemodulator
UE specific
cell specific
descrambling
ACK/NACK
channelestimation2
separateusersaccordingtoorthogonal
coversequence(despreading)
despreading
separateusereaccordingto
orthogonalsequence
PUCCH processing Rx
format 1a, 1b

spreading
with
sequence
for
mapping
to outer
RBs
for
mapping
to in
RBs
Pseudo-Random
sequence generator
cell
IDinit Nc =
(2)
RBN
(1)
csN
),(cell
cs lnn s
)()(
, nr vu
α
12PUCCH
seq =N
spreading
with
orthogonal
sequence
12symbols
)(oc
iwn
4PUCCH
SF =N
UE specific
cell specific
scrambling
spreading
with
sequence
)()(
, nr vu
α
12PUCCH
seq =N
modulation:
d(0),…d(19)
on QPSK
36.211, 7.1
d(20), d(21)
according to
36.211, Table
5.4.2-1
resource index (2)
PUCCHn
Resourcem
apper
(k,l,slot#)
IFFT
CP attach
(1)
PUCCHnresource index
determines cyclic shift
and orthogonal sequence
12symbols
input sequence for format 1
input sequence for format 2
Demodulation reference signals
for PUCCH format 2

3 x
repetition
ACK/NACK
1 bit
BPSK
(I or Q)
symbol level
Spreading,
length 4
orthogonal
sequence
3bit
super-position
of different
ACK/NACKS
3 symbols 12 symbols
resource mapper,
PHICH group is
mapped to 3 groups
of 4 REs
scrambling
12symbols
layer mapper
SISO or MIMO TD
FFT / CP
insertion
MIMO
channel
CP
removal/IFFT
resource
demapper
MIMO detectordescrambling
matched filter
length(12)
ACK/NACK
1 bit
other
ACK/NACK
1 bit
other
ACK/NACK
1 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 specific
scrambling
scrambling
tail bit
convolutional
encoder, rate 1/3
QPSK
modulation
layer mapping for
single antenna or
transmit diversity
precoding
SFD
resource
mapping
IFFT
CP inclusion
MIMO
channel
CP removel
FFT
Equalization
(SISO, MISO, or TD)
soft
demodulator
(QPSK)
channel estimates
Viterbi decoder
interleaver,
rate-matching
rate matching
buffer
CRC attach
CRC mask
code bit
extraction, CRC
computation
antenna
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,…
masked
CRC
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 specific
root-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
Channel
phase rotation,
(mixing,frequency
shift to DC)
decimation
1/24
LP filter
1/24
DFT 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 domain
replaced by multiplication in frequency domain

PCFICH
DL Control Format
block code
L=16
2 bits scambling
cell and
subframe
dependent
modulator
QPSK
layer
mapping
FFT / CP
insertion
power
boosting
power control
MIMO
channel
resource
mapper
(4 blocks of
4REs = 1RE
group)
cell ID
precoding
SISO or
Tx diversity
CP
removalII
FFT
resource
demap
MIMO
detection
demodulatordescrambling
block
detection
number of
OFDM symbols
reserve for control
1,2,3

Rate matching and HARQ processing
systematic
parity 1
parity 2
sub-block
interleaver
column permutation
write-in row-wise
read-out column-wise S1
P1
P2
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 Category
Maximum 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 buffer
x(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/NACK
Recall: 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
Downlink
subframe
Uplink
subframe
Special guard
subframe for
DL to UL switch
Special guard
subframe or
Downlink SF
Uplink or
Downlink
subframe
special subframe:
DL to UL switching
S
#1 or #6
DwPTS
GP UpPTS
DwPTS: DL pilot time slot
shortend 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
SSS
RSand
Control
PSS
0 1 2

TDD: UE ACK/NACK procedure
(PUSCH transmission and PHICH reception)
TDD UL/DL
Configuration
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 PHICH
in subframe i
•for UL transmission in subframe i - k,
where the values for k are given in
the table.
k for TDD configurartion 0-6
TDD UL/DL
Configuration
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 in
the table.
UE Tx Perspective

DL control issues in TDD DL HARQ
TDD
UL/DL
Config.
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/DL
Config.
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 DAI
to 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/DL
Config.
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/DL
Config.
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
DAI
MSB,
LSB
UL
DAIV DL
DAIVor

End of Part 1
Thank you!!!

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