4 td lte(á¶ºà¿-) (1)

TD-LTE Overview

November 2012

Bong Youl (Brian) Cho, 조 봉 열

[email protected]

mailto:[email protected]

TTA LTE/MIMO Standards/Technology Training

2 © Nokia Siemens Networks

Contents

• Why TD-LTE?

• NSN with TD-LTE

• TD-LTE technology overview



Why TD-LTE?



Difference b/w 3G-TDD and 4G-TDD

1999 2000 2001 2002 2003 2004 2005

Rel 99

Rel 4

Rel 5

Rel 6

1.28Mcps TDD

HSDPA, IMS

W-CDMA

HSUPA, MBMS, IMS+

2006 2007 2008 2009

Rel 7 HSPA+ (MIMO, HOM etc.)

Rel 8

2010 2011

LTE, SAE

Rel 9

LTE-Advanced Rel 10

GSM/GPRS/EDGE enhancements

Small LTE/SAE enhancements

LTE-Advanced

2012

Rel 11

OFDM기반의 기술 추가 및 MIMO의 본격적인 활용



Global TDD Situation

4+

Frequencies

50+

Countries

60%

World Pops

50%

Land-Mass

2.3 Global

2.6 Global

1.9 Russia, China

2.5 Japan

Informa

Over 50% of operators planning to deploy TD-

LTE



3GPP E-UTRA TDD frequency bands

E-UTRA

Operating

Band

Uplink (UL) operating band

BS receive UE transmit

Downlink (DL) operating band

BS transmit UE receive Duplex

Mode

FUL_low – FUL_high FDL_low – FDL_high

33 1900 MHz – 1920 MHz 1900 MHz – 1920 MHz TDD














LTE-FDD, TD-LTE Integration

Standards Integration

Product Integration

Maximized commonality b/w FDD and TDD for high level of integration/interworking

FDD-LTE

TD-LTE

Glo

bal

Ro

am

ing

FDD-LTE & TD-LTE

TD

-LT

E / F

DD

-LT

E

Tra

nsp

are

nt

han

d o

ver

Fully integrated over time



TD-LTE Capacity Similar spectral efficiency for TD-LTE and LTE-FDD

5

10

15

20

25

30

35

FDD 2 x 10MHz TD-LTE 1 x 20MHz TD-LTE 1x20MHz ( FDD 2 x 20MHz )

Mbps

Downlink

Uplink

TD-LTE config.1

• DL/UL = 4/4 timeslots

• Similar DL and UL capacity as in FDD

TD-LTE config.2

• DL/UL = 6/2 timeslots

• Optimized for very asymmetric traffic

FDD-LTE

• DL = 10MHz

• UL = 10MHz

FDD-LTE

• DL = 20MHz

• UL = 20MHz

• Double spectrum

= double capacity

Similar Spectrum Efficiency

DL/UL Ratio

Flexibility



TD-LTE – a very relevant tool for every operator

TD-LTE Early Market Opportunity

True 4G performance Comparable Performance FDD-LTE

Global & Local Roaming TD-LTE / FDD-LTE / 3GPP / 3GPP2

Affordable Spectrum Sold for 10x less than FDD equivalent

Economy of Scale • LTE Momentum Driving

Common Network Hardware

• Large Operators TD-LTE Opportunities Driving the Device Economy of Scale

Traditional CSP – Augment FDD-LTE

• Increased Capacity (Overlay/Underlay)

• or specific Apps (M2M, Video Broadcast)

Greenfield – TD-LTE main LTE network

Global roaming + potential MVNO capability with other 3GPP/3GPP2 operators for underlay in early deployment stage with transparent

WiMAX CSP – Possible migration path

• Leverage current spectrum asset

• Scope for evolution to TD-LTE when time is right



TD-LTE Applications Leveraging Flexible DL/UL Ratio

Mobile Reporter

- TD-LTE enable report to leverage the power of now in the field and with HD Quality and instantaneity for live studio-like dialog

- Avoid Complex, Slow & Costly deployment of TV vehicles on site UL Bias Use Case

Surveillance & Video based M2M

UL Bias Use Case

• Spot Coverage of Crowd Based Events/Gathering, Public Safety Incidents / Traffic Monitoring, Hazardous places access, Remote People monitoring, ...

- Leverage HD quality video uplink, responsive service with very long distance remote control capabilities

Transport On-Board Infotainment

DL Bias Use Case

- Layer coverage of transport networks for added capacity and supporting the infotainment nature of the likely applications used during transport

- Leverage Very High Downlink Capacity for fixed line BB like service for supporting more subscribers and high quality and innovative applications



NSN with TD-LTE



Nokia Siemens Networks LTE references 67 commercial LTE customers

61 LTE radio deals (incl. 8 TD-LTE)

32 LTE EPC deals commercially launched networks (incl. 5 TD-LTE)

35

Canada Sweden Sweden Latvia Latvia

Korea

Canada

Russia Denmark Denmark Finland Finland Lithuania

Korea

USA

Poland USA Germany Germany Estonia Estonia South

Korea USA

IMS

France Croatia Austria Slovenia India Singapore Japan

Portugal Italy Azerbaijan Bahrain Australia Japan

UAE Saudi Arabia Saudi Arabia Japan

LTE supplier to the largest operators in Japan and Korea

Brazil

TD-LTE

TD-LTE TD-LTE

TD-LTE



TD-LTE Developments

Award The Economic Figure of the

Year of the China Information Industry

for NSN innovation & leadership in TD-LTE

China Information Industry Economic Conference

Beijing, Dec 1st 2011

1st TD-LTE Femto cell demo

World’s 1st

1st CMCC/ VDF proof of tech.

100% pass MIIT lab test

E2E call with throughput >80Mbps end-to-end

2.3GHz

MIIT field trial test

IOT with UE vendors (incl. Altair, Sequans, HiSilicon, Innofidei, Qualcomm)

1st TD-LTE demo in India & Russia

1st Taiwan-Mainland TD-LTE live HD video

1st TD LTE-TD SCDMA video call controlled by IMS

1st TD-LTE – TD-SCDMA concurrent mode

World’s 1st

1st TD-LTE trial network parallel connecting to CMCC, Shanghai Expo

1st TD-LTE Open Lab

World’s 1st

Simultaneous multiple UE TD-LTE connection

World’s 1st

3GPP R8 TD-LTE E2E L3 call with comm. EPC

3GPP R8 TD-LTE call & HO

World’s 1st

World’s 1st

TD-LTE drive tour at ITU Geneva

World’s 1st

Leading vendor in MIT 2.6 GHz field trial

Successful trials in India and Russia

3 Large scale trials slots in CMCC large field trial

2010 2009 2012

First 1.3Gbps demo for LTE-A with CMCC

First to finish CMCC Ph1 large scale testing (97%)

2011

Progress

• Demos since 2009

• Commercial deals since 2011

• Significant deployments 2012

• 7 commercial deals to date

(leading)

We are here



NSN extends TD-LTE speed record in China



TD-LTE technology overview



Duplexing

• FDD

• TDD



Duplexing – cont’d



LTE FDD vs TD-LTE

Same RF Structure, Same Resource Block => Same RF Power/Time/Bandwidth Density

Same Power Transmitted during the Same amount of time as FDD-LTE

LTE FDD

10MHz

10W

5W

5MHz

5MHz

10ms

10ms

TD-LTE

DL

DL Single UL Frame Resource Block

5ms

Power

Time

Spectrum

1/5 W

UL

UL

1/5 W



3GPP LTE FDD vs. LTE TDD High degree of commonality

Features LTE FDD LTE TDD

Frame structure 1ms sub-frame 1ms sub-frame

Switching points N/A 5ms periodicity and 10 ms periodicity

BS Synchronization Asynchronous/Synchronous Synchronous

DL Control Channel Can schedule 1 DL and 1 UL

sub-frame at a time

Can schedule 1 DL and multiple

UL sub-frame at a time

UL Control Channel Single ACK/NAK corresponding

to 1 DL sub-frame

Multiple ACK/NAK corresponding

to multiple DL sub-frame

PRACH 0,1,2,3 0,1,2,3,4 (Short RACH)

Special slot usage N/A DwPTS: RS, Data and Control

UpPTS: SRS and Short RACH

Numerology, Coding, Multiple

Access, MIMO support, RS

etc.

Same Same

HARQ Timing N=8 stop-and-wait protocol

DL: Async, UL: Sync

TBD

DL: Async, UL: Sync

High Degree of Commonality



LTE FDD vs. TDD performance comparison

FDD-LTE TD-LTE

Negligible advantage (No need of switching) Spectral Efficiency

DL/UL Balancing TD-LTE can adapt to DL/UL traffic ratio

(typical of internet traffic) Fix bandwidth for DL & UL

(typical of voice traffic)

Real Life Performance

Latency Dedicated UL/DL pipes (no need to “wait” for

UL or DL slot)

Comparable Subscriber Experience

Slightly longer latency

Coverage

Spectrum Flexibility

New Spectrum Pricing Because of higher demand FDD has so far

sold for higher $/MHz TDD Spectrum had traditionally auctioned for

lower $/MHz

Coexistence Coexistence requirement for adjacent

frequency in the same geographic area

+

+

+

+

+

Better in big-sized cells + Paired-band is not needed, no duplexing gap +



Frame Structure

#0 #1 #2 #3 #19

One slot, Tslot = 15360Ts = 0.5 ms

One radio frame, Tf = 307200Ts=10 ms

#18

One subframe

Type 2 for TDD

Type 1 for FDD

One slot,

Tslot=15360Ts

GP UpPTSDwPTS

One radio frame, Tf = 307200Ts = 10 ms

One half-frame, 153600Ts = 5 ms

30720Ts

One subframe,

30720Ts

GP UpPTSDwPTS

Subframe #2 Subframe #3 Subframe #4Subframe #0 Subframe #5 Subframe #7 Subframe #8 Subframe #9



Frame Structure: FDD/TDD



TD-LTE: UL/DL configurations

Configuration Switch-point periodicity Subframe number

0 1 2 3 4 5 6 7 8 9

0 5 ms D S U U U D S U U U

1 5 ms D S U U D D S U U D

2 5 ms D S U D D D S U D D

3 10 ms D S U U U D D D D D

4 10 ms D S U U D D D D D D

5 10 ms D S U D D D D D D D

6 5 ms D S U U U D S U U D



TD-LTE: UL/DL configurations



* assuming Normal CP

TD-LTE: Special subframe config for max cell range



Mapping of control channels to TDD config #1

<cf> FDD LTE



Coexistence among neighboring TDD systems



Typical RF interference scenario for a TDD



Coexistence b/w TD-SCDMA and TD-LTE



Coexistence b/w WiMAX (16e) and TD-LTE



System Information

• Master information block (MIB) includes the following information:

– Downlink cell bandwidth [4 bit]

– System Frame Number (SFN) except two LBSs

– Etc…

• LTE defines different SIBs:

– SIB1 includes info mainly related to whether an UE is allowed to camp on the cell. This includes info

about the operator(s) and about the cell (e.g. PLMN identity list, tracking area code, cell identity,

minimum required Rx level in the cell, etc), DL-UL subframe configuration in TDD case, and the

scheduling of the remaining SIBs. SIB1 is transmitted every 80ms.

– SIB2 includes info that UEs need in order to be able to access the cell. This includes info about the UL

cell BW, random access parameters, and UL power control parameters. SIBs also includes radio

resource configuration of common channels (RACH, BCCH, PCCH, PRACH, PDSCH, PUSCH,

PUCCH, and SRS).

– SIB3-4 mainly includes info related to cell-reselection.

– SIB5-8 include neighbor-cell-related info. (E-UTRAN, UTRAN, GERAN, cdma2000)

– SIB9 contains a home eNB identifier

– SIB10/11 contains ETWS (Earthquake and Tsunami Warning System) notification

– SIB12: CMAS

– SIB13: eMBMS

– More to be added

• MIB mapped to PBCH, Other SIBs mapped to PDSCH



Coexistence b/w TDD and FDD



MIMO Spatial Multiplexing (SM)

Multiple Input Multiple Output (MIMO)

Multiple antennas at both transmitter and receiver

MIMO uses multipath to advantage to “multiply data rate” • Transmits different data along different paths (simplified view)

• MxN MIMO can multiply data rate by M or N (whichever is less) if there is enough multipath. – Best in urban high-multipath environment (and indoors)

– Less effective in suburban and rural low-multipath environments



How can we get multiplexing?

Simple concept

(1) Transmit “one” data in one link (1 Tx & 1 Rx antenna)

(2) Transmit “two” data in two links far away from each other (1 Tx & 1 Rx antenna, respectively)

(3) Transmit “two” data in one link (1 Tx & 1 Rx antenna) ??

(4) Transmit “two” data in one link (2 Tx & 2 Rx antenna) ??

(4) is just the special case of (2)!!

Simple linear algebra – Matrix (행렬)

– Rank

Favorable channel condition for MIMO SM? – Rich scattering (i.e. multipath) for high rank

– High SINR for reliable decoding



SVD MIMO as a closed-loop MIMO

?

• In CL-SU-MIMO, SVD-MIMO is the optimum



MIMO Channel Decomposition



x~x

V VH U UH

y

minn

1 1~w

min

~nw

Pre-processing Post-processing Channel

),0(~,, 0 r

rt

n

nnNΝCC Iwyx

wHxy

y~

With number of transmitting antenna=nt and receiving antenna=nr,

MIMO Channel Decomposition



wxDy ~~~

wUxD

wxVUDVU

wxUDVU

wHxU

yUy

H

HH

HH

H

H

~

)~(

)(

)(

~

Channel Diagonalization



Codebook for Precoding – 2 ports

• For transmission on two antenna ports, , the precoding matrix shall be selected from Table 6.3.4.2.3-1 or a subset thereof.

1,0p )(iW



Codebook for Precoding – 4 ports

• The quantity denotes the matrix defined by the columns given by the set from the expression where I is the 4x4 identity matrix and the vector is given by Table 6.3.4.2.3-2.

}{snW }{s

nHn

Hnnn uuuuIW 2

nu



3GPP Release 8 DL transmission modes Two approaches to multi-antenna transmission

MCS

CQI

PMI

Rank CQI

MCS

PMI

Rank

PDSCH Channel estimation based on common reference signal (CRS)

MIMO Beamforming

PDSCH Channel estimation based on dedicated reference signal (DRS)

CRS DRS

SRS

Closed loop, codebook precoding (TM4) Open loop, non-codebook precoding (TM7)

If UE uses multiple receive antennas, it also has to transmit SRS on multiple antennas in order for UL measurements to fully reflect DL channel state



• Diversity

– Same data on all the pipes (mode 2)

Increased coverage and link quality

– But, the all pipes can be combined to make a kind-of beamforming

• MIMO

– Different data streams on different pipes (mode 4)

Increased spectral efficiency (increased overall throughput)

Power is split among the data streams

• Beamforming

– Data stream on only the strongest pipe (mode 7)

Utilize different amplitude/phase at all pipes to optimally match per-UE radio condition

Increased coverage and signal SNR

Multi-Antenna Technology Summary



3GPP Release 9/10 DL transmission modes Enhanced beamforming: dual-layer beamforming (TM8) Multi-layer (TM9)

With cross polar antennas in mind TDD operators have been eager to extend Rel8 Beamforming to support two streams.

Spatial multiplexing supported

- Up to 2 layers per user (SU-MIMO)

- Up to 4 layer in total (MU-MIMO)

CRS based PMI and rank reporting supported for beamforming

- Similar feedback schemes as for Rel-8 SU-MIMO (tx-mode 4)

- TxD CQI also supported

- One CRS per polarization via sector beam virtualization (as in Rel-9)

CQI

PMI

Rank

MCS

Rank

PDSCH Channel estimation based on DRS

DRS

SRS



PDSCH Transmission Modes

Mode Details

1 Single-antenna transmission

2 Transmit diversity

3 Open-loop codebook-based precoding in the case of more than one layer, transmit diversity in the case of rank-one transmission

4 Closed-loop codebook-based precoding

5 Multi-user-MIMO version of transmission mode 4

6 Special case of closed-loop codebook-based precoding limited to single-layer transmission

7 Release-8 non-codebook-based precoding supporting only single-layer transmission

8 Release-9 non-codebook-based precoding supporting up to two layers

9 Release-10 non-codebook-based precoding supporting up to eight layers



Cell-Specific RS Mapping

Normal CP Extended CP

1 Tx ant 4.76% 5.56%

2 Tx ant 9.52% 11.11%

4 Tx ant 14.29% 15.87% 0l

0R

0R

0R

0R

6l 0l

0R

0R

0R

0R

6l

On

e an

ten

na

po

rtT

wo

an

ten

na

po

rts

Resource element (k,l)

Not used for transmission on this antenna port

Reference symbols on this antenna port

0l

0R

0R

0R

0R

6l 0l

0R

0R

0R

0R

6l 0l

1R

1R

1R

1R

6l 0l

1R

1R

1R

1R

6l

0l

0R

0R

0R

0R

6l 0l

0R

0R

0R

0R

6l 0l

1R

1R

1R

1R

6l 0l

1R

1R

1R

1R

6l

Fo

ur

ante

nn

a p

ort

s

0l 6l 0l

2R

6l 0l 6l 0l 6l

2R

2R

2R

3R

3R

3R

3R

even-numbered slots odd-numbered slots

Antenna port 0


Antenna port 1


Antenna port 2


Antenna port 3

RS Overhead



UE-specific RS (R5) on top of CRS

• UE-specific RS (antenna port 5)

– 12 symbols per RB pair

• DL CQI estimation is always based on cell-specific RS (common RS)



New DM-RS for scalability



• Diversity

– Same data on all the pipes (mode 2)

Increased coverage and link quality

– But, the all pipes can be combined to make a kind-of beamforming

• MIMO

– Different data streams on different pipes (mode 4)

Increased spectral efficiency (increased overall throughput)

Power is split among the data streams

• Beamforming

– Data stream on only the strongest pipe (mode 7)

Utilize different amplitude/phase at all pipes to optimally match per-UE radio condition

Increased coverage and signal SNR

– Not any more focusing on the strongest pipe in transmission mode 8 in R9 and mode 9 in R10

Multi-Antenna Technology Summary



LTE FDD vs TD-LTE link budget comparison (700MHz example)



3GPP Defined LTE CA Band Combinations

Release 10 • Band1 + Band5 LG U+

Release 11 Work Items • LTE_CA_B1_B7: LTE Advanced Carrier Aggregation of Band 1 and Band 7

• LTE_CA_B1_B18: LTE Advanced Carrier Aggregation of Band 1 and Band 18




• LTE_CA_B3_B5: LTE Advanced Carrier Aggregation of Band 3 and Band 5 SK Telecom

• LTE_CA_B3_B7: LTE-Advanced Carrier Aggregation of Band 3 and Band 7

• LTE_CA_B3_B8: LTE-Advanced Carrier Aggregation of Band 3 and Band 8 KT












• LTE_CA_B7: LTE Advanced Carrier Aggregation in Band 7

• LTE_CA_B25: LTE Advanced Carrier Aggregation Intra-Band, Non-Contiguous in Band 25



* CA Band Combination은 사업자의 요구에 따라 지속적으로 늘어남

CA for TD-LTE

Carrier aggregation is supported for both FDD and TDD, although all component carriers need to have the same duplex scheme.

In the case of TDD, the uplink–downlink configuration should be the same across component carriers.

The special subframe configuration can be different for the different components carriers though, as long as the resulting downlink–uplink switch time is sufficiently large.



HARQ Retransmission Timing

• Acknowledgement of a transport block in subframe n is transmitted in subframe n + k , where k ≧ 4 and is selected such that n + k is an uplink subframe



HARQ Acknowledgement Bundling

• For DL transmissions, there are some configurations where DL-SCH receipt in multiple DL subframes needs to be acknowledged in a single UL subframe

– Multiplexing

Independent acknowledgements for each of the received transport blocks are fed back to the eNodeB. This allows independent retransmission of erroneous transport blocks. However, it also implies that multiple bits need to be transmitted from the terminal.

– Bundling of acknowledgements

The outcome of the decoding of DL transport blocks from multiple DL subframes can be combined into a single hybrid-ARQ acknowledgement transmitted in UL. Only if both of the DL transmissions in subframes 0 and 3 in the example below are correctly decoded will a positive acknowledgement be transmitted in UL subframe 7.

The downlink assignment index in the scheduling assignment on the PDCCH is used to avoid confusion



UL Grant Timing

• For TDD configurations 1–6, the uplink transmission occurs in subframe n + k , where k is the smallest value larger than or equal to 4 such that subframe n + k is an uplink subframe.

• For TDD configuration 0 there are more UL subframes than DL subframes, which calls for the possibility to schedule transmissions in multiple UL subframes from a single DL subframe. For DL-UL configuration 0, the index field specifies which UL subframe(s) a grant received in a DL subframe applies to.



Random Access

• Short PRACH preamble (format 4) only for TD-LTE (to utilize UpPTS in small cells)

• For TDD, multiple random-access regions can be configured in a single subframe.

The reason is the smaller number of uplink subframes per radio frame in TDD. To

maintain the same random-access capacity as in FDD, frequency-domain

multiplexing is sometimes necessary.



Better Utilization of SRS

• SRS (Sounding Reference Signal)

– SRS can be used for both DL beamforming and UL CAS

• Calibration needed for channel reciprocity

Model to illustrate the impact from RF units to channel reciprocity (capital letters indentify matrixes)



FDD-TDD Handover

FDD - TDD mobility

• Network controlled

• Event triggered based on DL measurement RSRP and RSRQ

• Inter frequency measurements triggered by events A1/A2

• Configurable thresholds for

coverage based (A5),

best cell based (A3) handover

MME S-GW



TD-LTE is IMT-Advanced approved too!



TD-LTE Summary

• Market potential

• High level of commonality b/w FDD LTE and TD-LTE

• Slight difference in frame structure (FDD vs. TDD)

• Time synchronized network

• Need to ensure coexistence b/w neighboring TDD systems

• Better beamforming performance with channel reciprocity

• Smaller link budget which fits to capacity networks

• Flexible DL/UL capacity for various applications



Thank you !

www.nokiasiemensnetworks.com

Nokia Siemens Networks

20F, Meritz Tower, 825-2

Yeoksam-Dong, Kangnam-Gu

Seoul 135-080, Korea

Bong Youl (Brian) Cho Lead Product Manager Korea, Ph.D.

LTE Business Line, MBB

[email protected]

Mobile 010-4309-4129

mailto:[email protected]

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