It’s Time for TD-LTE - Keysight€™s Time for TD-LTE Presented by: Bai Ying, ... • Technical differences between FDD and TDD • Hot topics in TD-LTE • Agilent solutions for

© 2012 Agilent Technologies

Wireless Communications

Greater insight. Greater confidence. Accelerate next-generation wireless.

It’s Time for TD-LTE

Presented by: Bai Ying, Agilent Technologies



Greater insight. Greater confidence.

Accelerate next-generation wireless.

Agenda Today

• TD-LTE background

• Worldwide rollouts for TD-LTE

• Key players for TD-LTE industry

• Technical differences between FDD and TDD

• Hot topics in TD-LTE

• Agilent solutions for TD-LTE and TD-LTE-A

• Wrap up





China Mobile and TD-LTE

China MobileGSM

subscribersTD-SCDMA subscribers

TD-LTE subscribers

No.of users 600M 54M Opportunity

Market Share 73.9% 43% Opportunity

For 2G, China Mobile was dominant, but is facing strong

competition in 3G

China Mobile’s Key Contributions for TD-LTE industry

• In 2007, merged two TDD frame types into a unique one.

• In 2010, put dual layer beamforming in LTE release 9 standards

• In 2011, began “6+1” mode trial network, cover 83M population, 10

infrastructure vendors and 6 chipset vendors.

• In 2012, will begin per-commercial service





TDD Attracts Worldwide Attention TDD spectrum has been cheaper than FDD

Source: Ovum

India’s BWA auction boosted the industry’s interest in LTE TDD• Operators from Asia, Europe, North America, South America

and Oceania have built up to 32 trial networks so far.





TD-LTE vs WiMAX

Change

direction??

TD-LTE is from the 3GPP family

WiMAX is TDD technology, it competes with TD-LTE directly

WiMAX operators are switching to TD-LTE





Agenda Today







• Wrap up





TD-LTE worldwide rollouts

7 cities trial

network in China

Commercial

Launch in

Softbank

Commercial

launch in Mobily

and STC

(Saudi Arabia)

NBN in

Australia,

biggest TD-

LTE contract

so far

Swedish carrier Hi3G has announced that the

world's first commercial LTE FDD/TDD dual-mode

network has gone live in Stockholm, Gothenburg

and Malmo. Later, Hi3G is planning to extend the

network to whole of Sweden.

Areo2 in

Poland

33 trial networks

3 commercial network

6 commercial contracts

10+ planned operators





Agenda Today







• Wrap up





TD-LTE Ecosystem





Agenda Today







• Wrap up





Technical differences between FDD and TDD

- Downlink

ScramblingModulation

mapper

Layer

mapperPrecoding

ScramblingModulation

mapper

layerscode words

CRC Channel Coding

CRC Channel Coding

Rate Matching

Rate Matching

code words

Resource element

mapperIDFT

Resource element

mapperIDFT

antenna ports

CP Insertion Shaping

CP Insertion Shaping

antenna ports

LTE downlink signal generation process

TDD and FDD

differences

Can you

tell who is

who?





Frame Structure for LTE FDD FDD: Uplink and downlink are transmitted

separately

#0 #2 #3 #18#1 ………. #19

One subframe

One slot, Tslot = 15360 x Ts = 0.5 ms

One radio frame, Tf = 307200 x Ts = 10 ms

Subframe 0 Subframe 1 Subframe 9

Frame Structure for TD-LTE

#0 #1 ……….

One subframe

One slot, Tslot = 15360 x Ts = 0.5 ms

One radio frame, Tf = 307200 x Ts = 10 ms

Subframe 0

DL subframe

Subframe 1

Special subframe

Subframe 9 DL/UL subframe

TDD: Uplink and downlink are transmitted in the same

spectrum

DwPTS GP UpPTS

#18 #19


- Downlink





TDD Downlink and Uplink Allocation

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

• 5ms switch-point periodicity

Subframe 0, 5 and DwPTS for downlink, Subframe 2, 7 and UpPTS for uplink

• 10ms switch-point periodicity

Subframe 0, 5,7-9 and DwPTS for downlink,Subframe 2 and UpPTS for Uplink

D: downlink; U: uplink; S: special





Special Subframe

Special

subframe

configuration

Normal cyclic prefix in downlink Extended cyclic prefix in downlink

DwPTS UpPTS DwPTS UpPTS

Normal

cyclic

prefix

in uplink

Extended

cyclic

prefix

in uplink

Normal

cyclic

prefix in

uplink

Extended

cyclic

prefix in

uplink

0

1

2

3

4

5

6

7 - - -

8 - - -

s6592 T

s2192 Ts2560 T

s7680 T

s2192 T s2560 T

s19760 T

s20480 T

s21952 T

s23040 T

s24144 Ts25600 T

s26336 T s7680 T

s4384 T s5120 Ts6592 T

s4384 T s5120 T

s20480 T

s19760 T

s23040 T

s21952 T

s24144 T

Golden Rule: the total length for DwPTS+GP+UpPTS = 1ms

DwPTS: Downlink Pilot Signal

GP: Guard Period

UpPTS: Uplink Pilot Signal





NsymbDL OFDM symbols (=7 OFDM symbols @ Normal CP)

Cyclic Prefix

160 2048 144 2048 144 2048 144 2048 144 2048 144 2048 144 2048 (x Ts)

1slot = 15360

0 1 2 3 4 5 6

Ts = 1 / (15000x2048)=32.552nsec1 slot

Subframe 0

P-SCH

S-SCH

PBCH

PDCCH

PDSCH

Reference Signal

Downlink FDD Resource Mapping

( Single Antenna Port )

10 2 3 4 5 6 10 2 3 4 5 6 10 2 3 4 5 6 10 2 3 4 5 6

1 frame





#0 #1 #8#2 #3 #4 #5 #6 #7 #9

10 2 3 4 5 6 10 2 3 4 5 6 10 2 3 4 5 6 10 2 3 4 5 6 10 2 3 4 5 6 10 2 3 4 5 6

NsymbDL OFDM symbols (=7 OFDM symbols @ Normal CP)

Cyclic Prefix

160 2048 144 2048 144 2048 144 2048 144 2048 144 2048 144 2048 (x Ts)

1slot = 15360

0 1 2 3 4 5 6

Ts = 1 / (15000x2048)=32.552nsec1 slot

Subframe 0Downlink

P-SCH

S-SCH

PBCH

PDCCH

PDSCH

Reference Signal

Uplink

Reference Signal

(Demodulation)

PUSCH

UpPTS

Downlink TDD Resource Mapping

( Single Antenna Port )

10 2 3 4 5 6 10 2 3 4 5 6

Subframe 1

(Special Field)

Subframe 2 Subframe 3





Format4 is only used in TD-LTE, and only when special subframe

configurations with UpPTS lengths 4384 .Ts and 5120.Ts only.


- PRACH

PRACH format4

TDD only!






- Sounding RS

In FDD, Sounding RS always transmitted in the first or last OFDMA

symbol

In TDD, Sounding RS always transmitted in UpPTS of special subframe

Special

Subframe

Downlink

Subframe

Uplink

SubframeSounding RS is very

important in TDD,

especially for

beamforming





Agenda Today







• Wrap up





TD-LTE Hot Topic

-Same Frequency Networking

Challenges for TD-LTE networking:• Limited frequency bands.

• Unlike FDD, TD-LTE usually works at 2.3G and 2.6GHz, not ideal for

signal propagation.

• Same frequency interference, especially at the cell edge where the

transmitting power is very high.

Uplink Downlink Mode

33 1900MHz-1920MHz 1900MHz-1920MHz TDD


……




LTE TDD frequency bands





FFR (Fractional Frequency Reuse ) concept

Basic idea is to adopt frequency multiplexing in the cell edge to avoid inter-cell inference.

• Full bandwidth usage around the center of eNB

• Fractional frequency reuse at the cell edge

• Significantly improve the cell edge UE coverage

and user experience

• Other technology is also used, such as

beamforming

TD-LTE Hot Topic

-Same Frequency Networking





What is Beamforming ?

• Used in radar, sonar, seismology, wireless communications, radio

astronomy, acoustics

• Takes advantage of multi-antenna interference to control directionality of

array transmission power

• Multi-antenna signals are weighted relatively in both magnitude and phase

to produce spatial selectivity

– Constructive (in-phase) interference power gain in desired directions

– Destructive (out-of-phase) interference power nulling in other directions

TD-LTE Hot Topic-Beamforming

-90 deg

-60 deg

-30 deg

0 deg

+30

deg

+60

deg

+90

deg| | | |

N Antenna Elements

Correlated co-polarized 0.5 wavelength

separation

Direction of

Constructive

Interference

Gain

Direction of

Destructive

Interference

Nulling

Antenna array geometry along with

relative per antenna element

mag/phase weightings determine

constructive/destructive interference pattern





Beamforming Advantages

• Beamforming Gain (dB) improvement compared toomnidirectional or broadcast transmission/reception.

– Important metric to TD-LTE eNB customers

– Increase cell-edge throughputs

– Increase cell coverage

• Spatial Selectivity improvement

– Mitigate inter-cell interferences

– Mitigate inter-user interferences

– Improve spectrum efficiency (SDMA, Space Division Multiple Access)

eNB

1

eNB

2

UE1

UE2

eNB

1

UE1

UE2

Null

Null






Trans

Mode

Transmission

scheme

Per User

Max

Layer

Description DCI

format

Release 8

TM1 SA Port 0 SISO/SIMO 1 SIMO for receive diversity case 1

TM2 Tx Div 1 Robust reception in low SINR

Alamouti SFBC for 2 ant ports, SBFC / FSTD for 4 ant ports

(NOTE: Also applied to all common control channels)

1

TM3 OL SU-MIMO 1-4 Maximise UE throughput in fast changing channel

Pre-defined Codebook based precoding selection

Fixed for 2Tx Ant, Cyclic for 4Tx Ant

Large-delay CDD

2A

TM4 CL SU-MIMO 1-4 Maximise UE throughput in slow changing channel

Dynamic Codebook based precoding selection

2

TM5 CL MU-MIMO 1 Maximise Cell Capacity (not a priority for initial deployments)

Space Division Multiple Access (SDMA)

Targeted for Linear Antenna Array

Allocate one layer per user, power offset indicated by PDCCH

1D

TM6 CL Rank=1 SM (BF) 1 Maximise SINR at UE (for low speed UE case)

Dynamic Single Layer Codebook based precoding selection

1B

TM7 Single Layer BF Port 5 1 Robust reception in low SINR, +interference null steering

Single Layer Beamforming using antenna array

Dynamic Non-codebook based precoding

1

Release 9

TM8 Single Layer BF Port 7 or 8

Dual Layer BF Port 7 and 8

(SU-MIMO or MU-MIMO)

1-2 for

SU-MIMO

1 for

MU-MIMO

Maximise UE throughput / Cell Capacity, + interference null steering

Single or Dual Layer Beamforming using antenna array

Dynamic Non-codebook based precoding

Eigen-beamforming

2B

TM7 & TM8

Beamforming

is current

TD-LTE

market focus


3GPP LTE transmission modes





Agilent TD-LTE beamforming measurement solution

Provide 8-channel phase coherent measurement solution to enable

verification and visualization of TD-LTE base station RF antenna

beamforming signals.






CAL

Coupler

eNB

RRHUE1

8-Ch TD-LTE MIMO / Beamforming

– Test Setup

eNB

BB

RF Splitter

Uplink feedback

(SRS, CQI, PMI, RI)

UE1 UL

Channel

Emulator

2x8

RF Circulator

RF Atten

UE1 DL

Channel

Emulator

8x2

~10dB

+45 degree polarization = A1, A2, A3, A4

-45 degree polarization = A5, A6, A7, A8

~0.5*lambda spacing

(e.g. ~65mm)

A1 A2 A3 A4

A5 A6 A7 A8

CAL

Ant 1Ant 2

Ant 3

Ant 4

Ant 5

Ant 6Ant 7

Ant 8





CAL

Coupler

eNB

RRH

UE1 DL

Channel

Emulator

8x2

UE1

Uplink feedback

(SRS, CQI, PMI, RI)

UE1 UL

Channel

Emulator

2x8

eNB

BB

RF Splitter

RF Circulator

RF Atten

~10dB

Customer problem, need to verify

eNB RF Antenna calibration performance

+

BB encoded beamforming weightings

+

Demodulate MIMO dual layer EVM



~0.5*lambda spacing

(e.g. ~65mm)

A1 A2 A3 A4

A5 A6 A7 A8

CAL

Ant 1Ant 2

Ant 3

Ant 4

Ant 5

Ant 6Ant 7

Ant 8


– Test Setup





CAL

Coupler

eNB

RRHUE1

eNB

BB

RF Splitter

Uplink feedback

(SRS, CQI, PMI, RI)

UE1 UL

Channel

Emulator

2x8

RF Circulator

RF Atten

UE1 DL

Channel

Emulator

8x2

~10dB

MXG (with Dig Mod Option)

or ESG-C Custom Real Time

CAL REF SIGNALINJECT POINT

Agilent

N7100

8-Chan

Analyzer

Agilent 89600B VSA

~20dB



~0.5*lambda spacing

(e.g. ~65mm)

A1 A2 A3 A4

A5 A6 A7 A8

CAL

Ant 1Ant 2

Ant 3

Ant 4

Ant 5

Ant 6Ant 7

Ant 8


– Test Setup





IQ Constelation per

layer

8 Channel

UE-specific Weights

per layer / RB

Cell-RS

Impairments/weights

per antenna

UE-specific & broadcast

antenna patterns

per layer / RB / ant group

EVM

per layer


– Result Demo





Ant Group 0

pattern

Ant Group 1

pattern

8 Channel

UE-specific RS

Mag/Phase

Weights

per layer / RB


– Result Demo





Cell-RS raw data used to derive Common Broadcast pattern

Cell-RS

Broadcast

Pattern

8 Channel

Cell-RS

MIMO

Impairments


– Result Demo





Beamforming Gain trace

displays dB difference

between

UE-specific pattern and

Cell-RS broadcast pattern

New

Beamforming Gain

trace

Antenna Pattern

Format = IQ Polar

Can view Antenna Patterns in

either IQ Polar to LogMag(dB)

format

Antenna Pattern

Format = LogMag

(dB)


– Result Demo





Agenda Today







• Wrap up





Agilent Solutions for TD-LTE

ADS and

SystemVue

LTE VSA SWFor SAs, Scopes, LA,

SystemVue and ADS

Spectrum Analyzerswith LTE MsmtApps

Signal

Studio

Signal

Generators

PXB BB

Tester

N9912A

RF

Analyzer

RDX for

DigRF

v4

E6621A PXT

Communications Test

Set

N6070A LTE

signaling

conformance

test solutions

Cable antenna tester

& Spectrum analyzer

Battery

Drain Test

Systems for

RF and

Protocol

Conformanc

e

Scopes and

Logic

Analyzers

RF Module Development

RF Proto RF Chip/module

Design

Simulation

BTS and Mobile

BB Chipset Development

L1/PHYFPGA and ASIC

Conformance

RF and BB

Design

Integration

L1/PHY System

Design

Validation

System Level

RF TestingBTS

or

MobileProtocol Development

L2/L3

DigRF v4

Pre-Conformance

Network Deployment

Manufacturing

8-ch

N7109A

http://www.google.com/imgres?imgurl=http://magento.siteground.com/media/catalog/product/cache/17/image/5e06319eda06f020e43594a9c230972d/a/c/acer-ferrari-3200-notebook-computer-pc.jpg&imgrefurl=http://magento.siteground.com/index.php/theme6/acer-ferrari-3200-notebook-computer-pc.html&usg=__ZvOarwMeNYSA0pegKKs0nsUhoHo=&h=1100&w=1100&sz=47&hl=en&start=5&zoom=1&itbs=1&tbnid=DDvKfT1J2qggpM:&tbnh=150&tbnw=150&prev=/images?q=pc&hl=en&gbv=2&tbs=isch:1





LTE-Advanced timeline

ITU-R Submission Sept 2009Agilent Introduces first LTE Design Tools

First LTE Signal Generator

Demonstrates first LTE signal analysis

Agilent Introduces first LTE-Advanced

Design Tools, Signal Generation and

Analysis capabilities





Agilent Solutions for TD-LTE-Advanced

ADS

and

SystemVue

LTE VSA SWFor SAs, Scopes, LA,

SystemVue and ADS

Spectrum Analyzers

Signal

Studio

Signal

Generators

PXB BB

Tester

RF Module Development

RF Proto RF Chip/module

Design

Simulation

BTS and Mobile

BB Chipset Development

L1/PHY

FPGA and ASIC

Conformance

RF and BB

Design

Integration

L1/PHY System

Design

Validation

System Level

RF TestingBTS

or

MobileProtocol Development

L2/L3

DigRF v4

Pre-Conformance

Network Deployment

Manufacturing


Now in LTE-Advanced

8-ch

N7109A





Thanks!

Documents

It’s Time for TD-LTE - Keysight€™s Time for TD-LTE Presented by: Bai Ying, ... • Technical differences between FDD and TDD • Hot topics in TD-LTE • Agilent solutions for