Introduction to LTE-Advanced - Keysight... Dual Carrier HSDPA Rel-9 Dec 2009 Multi-standard Basestation, ... Link Budget template ... Introduction to LTE-Advanced Radio aspects 1

Concepts of 3GPP LTE

9 Oct 2007

Page 1© Copyright 2010 Agilent Technologies, Inc.

Introduction to

LTE-Advanced


9 Oct 2007

Page 2

Agenda

• LTE and LTE-Advanced at a glance

• Key LTE-Advanced documents

• LTE and LTE-Advanced timelines

•LTE-Advanced requirements

• Introduction to LTE-Advanced and design

challenges

•Agilent 4G/LTE-Advanced research initiatives

Page 2

Introduction to LTE-Advanced


9 Oct 2007

Page 3

UMTS Long Term Evolution

1999

2010

Release Functional

Freeze

Main feature of Release

Rel-99 March 2000 UMTS 3.84 Mcps (W-CDMA FDD & TDD)

Rel-4 March 2001 1.28 Mcps TDD (aka TD-SCDMA)

Rel-5 June 2002 HSDPA

Rel-6 March 2005 HSUPA (E-DCH)

Rel-7 Dec 2007 HSPA+ (64QAM DL, MIMO, 16QAM UL). LTE &

SAE Feasibility Study, Edge Evolution

Rel-8 Dec 2008 LTE Work item – OFDMA air interface

SAE Work item – New IP core network

UMTS Femtocells, Dual Carrier HSDPA

Rel-9 Dec 2009 Multi-standard Basestation, Dual Cell HSUPA

LTE-Advanced feasibility study, SON, LTE Femto

Rel-10 March 2011 LTE-Advanced (4G) work item, CoMP Study

Four carrier HSDPA

Page 3



9 Oct 2007

Page 4Page 4

SPEED!

Nov 2004 LTE/SAE High level

requirements

Reduced cost per bit

More lower cost services

with better user experience

Flexible use of new and

existing frequency bands

Simplified lower cost network with open

interfaces

Reduced terminal complexity and

reasonable power consumption

Spectral Efficiency

3-4x Rel-6 HSDPA (downlink)

2-3x HSUPA (uplink)

Latency

Idle active < 100 ms

Small packets < 5 ms

Downlink peak data rates

(64QAM)

Antenna

configSISO

2x2

MIMO

4x4

MIMO

Peak data

rate Mbps100 172.8 326.4

Uplink peak data rates

(Single antenna)

Modulation QPSK16

QAM

64

QAM

Peak data

rate Mbps50 57.6 86.4

MHz

1.4

3

5

10

15

20

Optimized: 0–15 km/h

High performance: 15-120

km/h

Functional: 120–350 km/h

Under consideration:

350–500 km/h

Mobility

Multiple Input Multiple Output

DL SU-

MIMO

MU-

MIMO

LTE at a glance!



9 Oct 2007

Page 5Page 5

MHz

1.4

3

5

10

15

20

Support for up to 5 Aggregated Carriers

MHz

1.4

3

5

10

15

20

MHz

1.4

3

5

10

15

20

MHz

1.4

3

5

10

15

20

MHz

1.4

3

5

10

15

20

SC-FDMA with

clustering!

Downlink MIMO Up to 8x8


DL

MIMO


DL

MIMO


DL

MIMO


DL

MIMO


UL

MIMO


UL

MIMO

Uplink MIMO Up to 4x4

LTE-Advanced Release 10 at a glance!


1 Carrier Aggregation

2 Enhanced uplink

3 Enhanced MIMO

Simultaneous

PUCCH/PUSCH


9 Oct 2007

Page 6Page 6

Additional items being studied for beyond

Release 10


4 Coordinated Multipoint

8 HeNB mobility enhancements

5 Relaying &

6 Self Optimizing Networks (SON)

7 Heterogeneous Networks


9 Oct 2007

Page 7

Key LTE-Advanced Documents

- and where to find them

Study Item RP-080599ftp://ftp.3gpp.org/tsg_ran/TSG_RAN/TSGR_41/Docs/RP-080599.zip

Requirements TR 36.913 v9.0.0 (2009-12)ftp://ftp.3gpp.org/Specs/html-info/36913.htm

Study Phase Technical Report TR 36.912 v9.3.0 (2010-06)ftp://ftp.3gpp.org/Specs/html-info/36912.htm

Latest study item status report RP-100080ftp://ftp.3gpp.org/tsg_ran/TSG_RAN/TSGR_47/Docs/RP-100080.zip

Physical Layer Aspects TR 36.814 v9.0.0 (2010-03)ftp://ftp.3gpp.org/Specs/html-info/36814.htm

The final specifications will start to show up in the

Release 10 36-series documents from 2010-09.

Page 7


ftp://ftp.3gpp.org/tsg_ran/TSG_RAN/TSGR_41/Docs/RP-080599.zip



ftp://ftp.3gpp.org/Specs/html-info/36913.htm













9 Oct 2007

Page 8

2005 2006 2007 2008 2009 2010

First GCF UE

certification

Rel-7 Feasibility study

Rel-8 Test development

2011 2012

Rel-8 Specification development

GCF Test validation

First Trial

Networks

First

Commercial

NetworksFurther

Commercial

Networks

LSTI Proof of Concept

LSTI IODT

LSTI IOT

LSTI Friendly

Customer Trials

LSTI = LTE/SAE Trial Initiative GCF = Global Certification Forum

LTE timeline

Page 8



9 Oct 2007

Page 9

LTE-Advanced timeline

Page 9

ITU-R Submission Sept 2009

TR36.912 v 2.2.0

R1-093731, Characteristic template

R1-093682, Compliance template

R1-093741, Link Budget template



9 Oct 2007

Page 10

LTE-Advanced Requirements & proposals

• LTE-A requirements are documented in TR 36.913, V9.0.0 (2009-03)

(Requirements for Further Advancements of E-UTRA (LTE-Advanced)

• 3GPP stated intention is to meet or exceed IMT-Advanced requirements

• LTE-A must support IMT-A requirements with same or better

performance than LTE

• LTE-A solution proposals can be found in TR 36.814 – “Further

Advancements for E-UTRA Physical Layer Aspects”

• Specific targets exist for average and cell-edge spectral efficiency (see

next slide)

• Similar requirements as LTE for synchronization, latency, coverage,

mobility…

• LTE-A candidate was submitted to ITU September 2009

Page 10



9 Oct 2007

Page 11

LTE-Advanced spectral efficiency requirements

Page 11

Item Sub-

category

LTE (3.9G)

target

LTE-Advanced

(4G) target

IMT-Advanced

(4G) target

Peak Spectral

Efficiency

(b/s/Hz)

Downlink 16.3 (4x4 MIMO) 30

(up to 8x8 MIMO)

15 (4x4 MIMO)

Uplink 4.32

(64QAM SISO)

15

(up to 4x4 MIMO)

6.75

(2x4 MIMO)

Downlink cell

spectral efficiency

b/s/Hz 3km/h

500m ISD

2x2 MIMO 1.69 2.4

4x2 MIMO 1.87 2.6 2.6

4x4 MIMO 2.67 3.7

Downlink cell-edge

user spectral

efficiency b/s/Hz 5

percentile 10 users

500m ISD

2x2 MIMO 0.05 0.07

4x2 MIMO 0.06 0.09 0.075

4x4 MIMO 0.08 0.12

ISD is Inter Site Distance 2x to 4x efficiency of Rel-6 HSPA



9 Oct 2007

Page 12


Overall aspects

• A comprehensive summary of the entire LTE-Advanced proposals including radio, network and system can be found in the 3GPP submissions to the first IMT-Advanced evaluation workshop.

http://www.3gpp.org/ftp/workshop/2009-12-17_ITU-R_IMT-Adv_eval/docs/

Page 12












9 Oct 2007

Page 13

New LTE-A UE Categories

To accommodate the higher data rates of LTE-A, three new

UE categories have been defined

Page 13

UE category

Max. Data

rate

(DL / UL)

(Mbps)

Downlink Uplink

Max. # DL-

SCH TB bits /

TTI

Max. # DL-

SCH bits

/ TB / TTI

Total. soft

channel

bits

Max. #.

spatial

layers

Max.# UL-

SCH TB bits /

TTI

Max. # UL-

SCH bits

/ TB / TTI

Support

for

64QAM

Category 1 10 / 5 10296 10296 250368 1 5160 5160 No

Category 2 50 / 25 51024 51024 1237248 2 25456 25456 No

Category 3 100 / 50 102048 75376 1237248 2 51024 51024 No

Category 4 150 / 50 150752 75376 1827072 2 51024 51024 No

Category 5 300 / 75 299552 149776 3667200 4 75376 75376 Yes

Category 6 300 / 50 [299552] [TBD] [3667200] [51024 ] [TBD] No

Category 7 300 / 150 [299552] [TBD] [TBD]

[150752/

102048 (Up-

to RAN4)]

[TBD]

Yes/No

(Up-to

RAN4)

Category 8 1200 / 600 [1200000] [TBD] [TBD] [600000] [TBD] Yes



9 Oct 2007

Page 14

Combinations of carrier aggregation and layers

There are multiple combinations of CA and layers that can

meet the data rates defined for the new and existing UE

categories

The following tables define the most probable cases for which

performance requirements will be developed

Page 14

UE categorycapability

[#CCs/BW(MHz)]

DL layers

[max #layers]

Category 6

1 / 20MHz 4

2 / 10+10MHz 4

2 / 20+20MHz 2

2 / 10+20MHz4 (10MHz)

2(20MHz)

Category 7

1 / 20MHz 4

2 / 10+10MHz 4

2 / 20+20MHz 2

2 / 10+20MHz4 (10MHz)

2(20MHz)

Category 8 [2 / 20+20MHz] [8]

UE categorycapability

[#CCs/BW(MHz)]

UL layers

[max #layers]

Category 6

1 / 20MHz 1

2 / 10+10MHz 1

1 / 10MHz 2

Category 7

2 / 20+20MHz 1

1 / 20MHz 2

2 / 10+20MHz2 (10MHz)

1 ( 20MHz)

Category 8 [2 / 20+20MHz] [4]

Downlink Uplink



9 Oct 2007

Page 15


Radio aspects

1. Carrier aggregation

2. Enhanced uplink multiple access

a) Clustered SC-FDMA

b) Simultaneous Control and Data

3. Higher order MIMO

a) Downlink 8x8

b) Uplink 4x4

4. Coordinated Multipoint (CoMP)

5. Relaying

6. Heterogeneous network support

7. Self Optimizing networks (SON)

8. Home eNB mobility enhancements

Page 15


Release 10

Beyond

Release 10


9 Oct 2007

Page 16

1. Carrier Aggregation

• Lack of sufficient contiguous spectrum up to 100 MHz forces

use of carrier aggregation to meet peak data rate targets

• Able to be implemented with a mix of terminals

• Backward compatibility with legacy system (LTE)

• System scheduler operating across multiple bands

• Component carriers (CC) - Max 110 RB (TBD)

• May be able to mix different CC types

• Contiguous and non-contiguous CC is allowed

Page 16

Contiguous aggregation of two

uplink component carriers

PUCCH

PUSCH


PUSCH


9 Oct 2007

Page 17


• IMT-Advanced requires at least 40 MHz, 100 MHz is a want

• Initially 12 scenarios were being studied, many more were proposed

• Due to complexity and limited time the study for Rel-10 is now limited

to just three scenarios:

• CA_40: Intra-band contiguous TDD

• CA_1-5: Inter-band non-contiguous FDD

• CA_3-7 Inter-band non-contiguous FDD

Page 17

Band

E-UTRA

operating

Band

Uplink (UL) band Downlink (DL) band

Duple

x

mode

UE transmit / BS receive Channel

BW

MHz

UE receive / BS

transmitChannel

BW

MHzFUL_low (MHz) – FUL_high

(MHz)

FDL_low (MHz) – FDL_high

(MHz)

CA_40 40 2300 – 2400 [TBD] 2300 – 2400 [TBD] TDD

CA_1-51 1920 – 1980 [TBD] 2110 – 2170 [TBD]

FDD5 824 – 849 [TBD] 869 – 894 [TBD]

CA_3-73 1710 – 1788 20 1805 – 1880 20

FDD7 2500 – 2570 20 2620 – 2690 20



9 Oct 2007

Page 18


Design and test challenges

• Not such an issue for the eNB

• Major challenge for the UE

• Multiple simultaneous receive chains

• Multiple simultaneous transmit chains

• Simultaneous non-contiguous transmitters creates a very

challenging radio environment in terms of spur management

and self-blocking

• Simultaneous transmit or receive with mandatory MIMO

support add significantly to the challenge of antenna design

Page 18



9 Oct 2007

Page 19

2. Enhanced Uplink Multiple Access

Clustered SC-FDMA and PUCCH with PUSCH

Partially allocated

PUSCH

Page 19


Release 8: SC-FDMA with

alternating PUSCH/PUCCH

(Inherently single carrier)

Proposed Release 10: Clustered SC-FDMA

with simultaneous PUSCH/PUCCH

(Potentially multi-carrier)

Partially allocated

PUSCH

Upper PUCCH

Fully allocated

PUSCH

Lower PUCCH

Partially allocated

PUSCH + PUCCH

Partially allocated

PUSCH + PUCCH

Partially allocated

PUSCH + 2 PUCCH

Partially allocated

PUSCH only

Fully allocated

PUSCH + PUCCH


9 Oct 2007

Page 20



• Clustered SC-FDMA increases PAR by a few dB adding to

transmitter linearity challenges

• Simultaneous PUCCH and PUSCH also increases PAR

• Both features create multi-carrier signals within the channel

bandwidth

• High power narrow PUCCH plus single or clustered SC-

FDMA creates large opportunity for in-channel and adjacent

channel spur generation

• May require 3 to 4 dB power amp backoff for Rel-8 PA

• Some scenarios may require 10 dB backoff.

• Due to the spur issues the status of the enhanced uplink is

still to be decided for Release 10

Page 20



9 Oct 2007

Page 21



Page 21

Source R4-100427 ftp://ftp.3gpp.org/tsg_ran/WG4_Radio/TSGR4_54/Documents/R4-100427.zip


-3 -2 -1 0 1 2 3

x 107

-90

-80

-70

-60

-50

-40

-30

-20

-10

0

10

20

30

Freq (Hz)

Mag (

dB

m)

Spectrum RBW=100kHz

The red trace is

the spectrum of

simultaneous

PUCCH at both

sides of the

channel

The blue trace

is the spectrum

of two adjacent

RB at the

channel edge

The existence of multiple carriers creates 40 to 50 dB higher spurs!

ftp://ftp.3gpp.org/tsg_ran/WG4_Radio/TSGR4_54/Documents/R4-100427.zip





9 Oct 2007

Page 22

3. Higher Order MIMO Transmission

• Up to 8x8 Downlink (from 4x2 for Rel-8)• Baseline being 4x4 with 4 UE Receive Antennae

• Peak data rate reached with 8x8 SU-MIMO

• Up to 4x4 Uplink (from 1x2 for Rel-8)• Baseline being 2x2 with 2 UE Transmit Antennae

• Peak data rate reached with 4x4 SU-MIMO

• Use of beamforming with spatial multiplexing

to increase data rate, coverage and capacity

• Challenges of higher order MIMO• Need for tower-mounted radio heads

• Increased power consumption

• Increased product costs

• Physical space for the antennae at both eNB and UE

Page 22

Max 4 layers

Max 1 layer

Max 8 layers

Max 4 layers

Rel-8 LTE

LTE-Advanced



9 Oct 2007

Page 23

3. Higher Order MIMO Transmission


• Higher order MIMO has a similar impact on the need for

simultaneous transceivers as does carrier aggregation

• However, there is an additional challenge in that the

antennas also have to multiply in number

• MIMO antennas also require to be de-correlated

• It is very hard to design a multi-band, MIMO antenna in a

small space with good de-correlation

• This makes conducted testing of higher order MIMO

terminals largely irrelevant in predicting the actual radiated

performance in an operational network

• There is a study item in Rel-10 looking at MIMO Over the Air

(OTA) testing which will address antenna performance

Page 23



9 Oct 2007

Page 24

4. Coordinated Multi-Point – (CoMP)

Downlink

• Coordinated scheduling / beamforming

• Payload Data is required only at the serving cell

• Coherent combining (also known as cooperative MIMO) / fast switching

• Payload data is required at all transmitting eNB

• Requires high speed symbol-level backhaul between eNB

Uplink

• Simultaneous reception requires coordinated scheduling

Page 24

Traditional MIMO – co-located transmission Coordinated Multipoint

eNB eNB 2

eNB 1

UE UE



9 Oct 2007

Page 25

4. CoMP status

• Recent simulation by RAN WG1 has shown initial CoMP

performance improvement to be in the 5% to 15% range.

• This is not considered sufficient to progress this aspect of the

proposals within the Rel-10 timeframe

• Recent results from the EASY-C testbed also show limited

performance gains in lightly loaded networks with minimal or

no interference

• CoMP will be studied further for Release 11

• It remains unclear what eNB testing of CoMP might entail

since it is very much a system level performance gain and

very difficult to emulate

Page 25



9 Oct 2007

Page 26

5. In-channel relay and backhaul

• Basic in-channel relaying uses a relay node (RN) that receives, amplifies

and then retransmits DL and UL signals to improve coverage

• Advanced relaying performs L2 or L3 decoding of transmissions before

transmitting only what is required for the local UE

Cell Edge

Area of poor coverage with

no cabled backhaul

Multi-hop relaying

Over The Air

backhaul

• OFDMA makes it possible to

split a channel into UE and

backhaul traffic

• The link budget between the

eNB and relay station can

be engineered to be good

enough to allow MBSFN

subframes to be used for

backhaul of the relay traffic

• Main use cases:

• Urban/indoor for

throughput or dead zone

• Rural for coverage

Page 26

eNB

eNB

RN

RN

RN



9 Oct 2007

Page 27

5. In-channel relay and backhaul


• From the UE perspective, relaying is completely transparent

• The challenge is all on the network side

• For the system to work, the link budget from the relay node

to the macro eNB must be good• This implies line of sight positioning

• The main operational challenge with getting relaying to work

will be in the management of the UE• The UE has to hand over to the relay node when in range

• It must release the relay node when out of range

• If this process is not well-managed, the performance of the

cell could go down not up

• Multi-hop relaying for coverage should be easier • e.g. a valley with no cabled backhaul

Page 27



9 Oct 2007

Page 28

6. Heterogeneous Network Support

• LTE-Advanced intends to address the support needs of

heterogeneous networks that combine low power nodes

(such as picocells, femtocells, repeaters, and relay nodes)

within a macrocell.

• Deployment scenarios under evaluation are detailed in TR

36.814 Annex A.

Page 28



9 Oct 2007

Page 29

7. Self Optimizing networks (SON)

• Today’s cellular systems are very much centrally planned,

and the addition of new nodes to the network involves

expensive and time-consuming work, site visits for

optimization, and other deployment challenges.

• One of the enhancements being considered for LTE-

Advanced is the self-optimizing network (SON).

• The intent is to substantially reduce the effort required to

introduce new nodes to the network. There are implications

for radio planning as well as for the operations and

maintenance (O&M) interface to the base station.

• Some limited SON capability was introduced in Release 8

and is being further elaborated in Release 9 and Release 10.

Page 29



9 Oct 2007

Page 30

• The concept of Home eNB (femtocells) is not new to LTE-A

• In Release 8 femtocells were

introduced for UMTS

• In Release 9 they were

introduced for LTE (HeNB)

• In Release 9 only inbound mobility

(macro to HeNB) was fully specified

• In Release 10 there will be further

enhancements to enable

HeNB to HeNB mobility

• This is very important for

enterprise deployments

8. Home eNB mobility enhancements

Page 30



9 Oct 2007

Page 31

Looking at the cost/benefits of LTE-Advanced

Radio aspects

Page 31

Carrier

AggregationEnhanced Uplink Higher order MIMO

CoMP

(Rel-11)

Relaying

(Rel-11)

Peak data

rates

Cell spectral

efficiency

(Downlink)

(Uplink)

Cell edge

performance

Coverage

UE cost

Network cost

UE Complexity

Network

Complexity



9 Oct 2007

Page 32

LTE-Advanced summary

• LTE-A is 3GPP’s submission to ITU-R IMT-Advanced “4G” program

• LTE-A is an evolution of LTE and is about two years behind LTE in

standards

• Rel-8 LTE almost meets the IMT-Advanced requirements except for

UL spectral efficiency and peak rates requiring wider bandwidths.

• Bandwidth up to 100MHz through aggregation of 20 MHz carriers

• Up to 1 Gbps (low mobility) with 8x8 MIMO

• Key new technologies include : carrier aggregation, enhanced uplink

and advanced MIMO

• Spectral efficiency performance targets are a step up from the

already very challenging Rel-8 LTE targets

• LTE-A Deployment timing is hard to predict and will depend heavily

on the rollout of LTE

Page 32



9 Oct 2007

Page 33

Agilent 4G/LTE-Advanced research initiatives

Continued long-term participation in 3GPP RAN committees

European projects:

• COST2100 (MIMO research)

• 4GMCT (4G Mobile Communication and Test)

• Agilent, Infineon, Aalborg University

• SAMURAI Spectrum Aggregation and Multi-User MIMO: ReAl-World Impact

• Agilent , Infineon, NSN, SEQUANS, Institut Eurecom, Budapesti

Műszaki és Gazdaságtudomány Egyetem

Page 33



9 Oct 2007

Page 34

Questions?

Page 34
