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Concepts of 3GPP LTE
9 Oct 2007
Page 1© Copyright 2010 Agilent Technologies, Inc.
Introduction to
LTE-Advanced
Concepts of 3GPP LTE
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
Concepts of 3GPP LTE
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
Introduction to LTE-Advanced
Concepts of 3GPP LTE
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!
Introduction to LTE-Advanced
Concepts of 3GPP LTE
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
Multiple Input Multiple Output
DL
MIMO
Multiple Input Multiple Output
DL
MIMO
Multiple Input Multiple Output
DL
MIMO
Multiple Input Multiple Output
DL
MIMO
Multiple Input Multiple Output
UL
MIMO
Multiple Input Multiple Output
UL
MIMO
Uplink MIMO Up to 4x4
LTE-Advanced Release 10 at a glance!
Introduction to LTE-Advanced
1 Carrier Aggregation
2 Enhanced uplink
3 Enhanced MIMO
Simultaneous
PUCCH/PUSCH
Concepts of 3GPP LTE
9 Oct 2007
Page 6Page 6
Additional items being studied for beyond
Release 10
Introduction to LTE-Advanced
4 Coordinated Multipoint
8 HeNB mobility enhancements
5 Relaying &
6 Self Optimizing Networks (SON)
7 Heterogeneous Networks
Concepts of 3GPP LTE
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
Introduction to LTE-Advanced
Concepts of 3GPP LTE
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
Introduction to LTE-Advanced
Concepts of 3GPP LTE
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
Introduction to LTE-Advanced
Concepts of 3GPP LTE
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
Introduction to LTE-Advanced
Concepts of 3GPP LTE
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
Introduction to LTE-Advanced
Concepts of 3GPP LTE
9 Oct 2007
Page 12
Introduction to LTE-Advanced
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
Introduction to LTE-Advanced
Concepts of 3GPP LTE
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
Introduction to LTE-Advanced
Concepts of 3GPP LTE
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
Introduction to LTE-Advanced
Concepts of 3GPP LTE
9 Oct 2007
Page 15
Introduction to LTE-Advanced
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
Introduction to LTE-Advanced
Release 10
Beyond
Release 10
Concepts of 3GPP LTE
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
Introduction to LTE-Advanced
PUSCH
Concepts of 3GPP LTE
9 Oct 2007
Page 17
1. Carrier Aggregation
• 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
Introduction to LTE-Advanced
Concepts of 3GPP LTE
9 Oct 2007
Page 18
1. Carrier Aggregation
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
Introduction to LTE-Advanced
Concepts of 3GPP LTE
9 Oct 2007
Page 19
2. Enhanced Uplink Multiple Access
Clustered SC-FDMA and PUCCH with PUSCH
Partially allocated
PUSCH
Page 19
Introduction to LTE-Advanced
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
Concepts of 3GPP LTE
9 Oct 2007
Page 20
2. Enhanced Uplink Multiple Access
Design and test challenges
• 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
Introduction to LTE-Advanced
Concepts of 3GPP LTE
9 Oct 2007
Page 21
2. Enhanced Uplink Multiple Access
Design and test challenges
Page 21
Source R4-100427 ftp://ftp.3gpp.org/tsg_ran/WG4_Radio/TSGR4_54/Documents/R4-100427.zip
Introduction to LTE-Advanced
-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!
Concepts of 3GPP LTE
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
Introduction to LTE-Advanced
Concepts of 3GPP LTE
9 Oct 2007
Page 23
3. Higher Order MIMO Transmission
Design and test challenges
• 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
Introduction to LTE-Advanced
Concepts of 3GPP LTE
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
Introduction to LTE-Advanced
Concepts of 3GPP LTE
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
Introduction to LTE-Advanced
Concepts of 3GPP LTE
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
Introduction to LTE-Advanced
Concepts of 3GPP LTE
9 Oct 2007
Page 27
5. In-channel relay and backhaul
Design and test challenges
• 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
Introduction to LTE-Advanced
Concepts of 3GPP LTE
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
Introduction to LTE-Advanced
Concepts of 3GPP LTE
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
Introduction to LTE-Advanced
Concepts of 3GPP LTE
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
Introduction to LTE-Advanced
Concepts of 3GPP LTE
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
Introduction to LTE-Advanced
Concepts of 3GPP LTE
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
Introduction to LTE-Advanced
Concepts of 3GPP LTE
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
Introduction to LTE-Advanced