rev-080019 consideration on technical candidates for imt-advanced date: april 7 th ~8 th, 2008...

REV-080019

Consideration on Technical Candidates for IMT-Advanced

Date: April 7th~8th, 2008

Agenda Item: 3

Source: LG Electronics, Inc.

3GPP RAN IMT-advanced Workshop

2Great Company Great People

Outline

◙ Overview of Target Features in IMT-advanced ◙ Approach toward LTE-advanced from 3GPP LTE ◙ Technical View for Enabling Technologies and System

Design of LTE-advanced Multi-hop relaying Bandwidth Assignment Enhanced MIMO LTE technical items to be enhanced


Main Features in IMT-advanced

◙ Service Perspective High quality mobile services Enhanced peak data rate to support advanced services and application Worldwide roaming capability Compatibility of services within IMT and with fixed networks Capability of interworking with other radio access systems

◙ Implementation Perspective A high degree of commonality of functionality worldwide while retaining the fl

exibility to support a wide range of services and applications in a cost efficient manner

User-friendly applications, services and equipment User equipment suitable for worldwide use

Source: Attachment 7.1 to Document 5D/97


Provisional View for IMT-advanced Requirement in ITU-R WP5D

Deployment environment

Requirement ParametersIndoor Microcellular

Base Coverage Urban

High Speed

Cell Spectral Efficiency

(bps/Hz/cell)

DL (4x2) 3 2.6 2.1 1

UL (2x4/1x4) 2.5/1.5 2/1.3 1.7/1.2 0.7/0.6

Peak Spectral Efficiency

(bps/Hz/cell)

DL (4x4/4x2) 10/7

UL (2x4/1x4) 5/2.5

Bandwidth (MHz) 20 or 40

Cell Edge Throughput

(bps/Hz)

DL 0.1 0.075 0.08 0.05

UL 0.08 0.05 0.03 0.02

Latency (ms)C-plane 100

U-plane 10

Handover Latency (ms)

Intra-freq. [25/30]

Inter-freq. N/A

Inter-sys. N/A

Mobility classStationary

Pedestrian

Stationary

Pedestrian

Stationary

Pedestrian

Vehicular

Vehicular

High Speed

Source: ITU-R WP5D IMT.TECH document, Feb. ’08 .


Overall Company Views on 3GPP RAN Specification of IMT-advanced

◙ Evolutionary Approach from 3GPP LTE Specification Very close potential of 3GPP LTE with target requirements of IMT-advanced Fast and efficient correspondence against the timeline of WP5D’s

specification and commercialization for IMT-advanced

◙ Careful Verification for Various Emerging Technology Candidates Feasibility at the commercial implementation time Accurate clarification for the trade-off between benefits and

overhead/complexity

◙ Efficient System Design for a New Value-added Service Creation Provisioning a technical background for development of killer applications in

IMT-advanced


System Comparison between 3GPP LTE and IMT-advanced (1/2)

◙ Peak Spectral Efficiency

Almost equal or better peak data rate potential of E-UTRAN compared with the related requirements of IMT-advanced

◙ Cell Spectral Efficiency

Higher cell spectral efficiency requirement of IMT-advanced than performance of E-UTRAN in

both uplink and downlink

System

Requirement Parameters3GPP LTE IMT-advanced

Peak Spectral Efficiency

(bps/Hz/cell)

DL 16.32 (4x4) / 8.64 (2x2) 10 (4x4) / 7 (4x2)

UL 4.32 (64QAM, 1x2) / 2.88 (16QAM, 1x2) 5 (2x4) / 2.5 (1x2)

System

Requirement Parameters

3GPP LTE IMT-advanced

ISD = 500m ISD = 1732m MicrocellularBase Coverage

Urban

Cell Spectral Efficiency

(bps/Hz/cell)

DL 2.67 (4x4)/1.87 (4x2)2.41 (4x4)/1.85

(4x2)2.6 (4x2) 2.1 (4x2)

UL0.776 (2x2)

/0.735(1x2) /1.103 (1x4)0.681(1x2) /1.038

(1x4)2 (2x4)/1.3 (1x4) 1.7 (2x4)/1.2 (1x4)

Source:

• ITU-R WP5D IMT.TECH document, Feb. ’08

• 3GPP RAN1 R1-072580, May ’07


System Comparison between 3GPP LTE and IMT-advanced (2/2)

◙ Cell Edge User Throughput

Higher cell edge throughput requirement of IMT-advanced than performance of E-UTRAN in both uplink and downlink

◙ Latency

Equal or better requirement of E-UTRAN than that of IMT-advanced including handover latency

System

Requirement Parameters3GPP LTE IMT-advanced

Latency (ms)C-plane 100 100

U-plane 5 10

System

Requirement Parameters

3GPP LTE IMT-advanced

ISD = 500m ISD = 1732m MicrocellularBase Coverage

Urban

Cell Edge User Throughput

(bps/Hz/user)

DL0.08 (4x4)/0.06

(4x2)0.08 (4x4)/0.05

(4x2)0.075 (4x2) 0.06 (4x2)

UL (2x4/1x2)0.01 (2x2)

/0.024(1x2) /0.052 (1x4)

0.0044(1x2) /0.0094 (1x4)

0.05 (1x4) 0.03 (1x4)

Source:

• ITU-R WP5D IMT.TECH document, Feb. ’08

• 3GPP RAN1 R1-072580, May ’07

• 3GPP TS25.912


Main Enhancement Factors of 3GPP LTE for Evolving toward LTE-advanced

◙ Quantitative Enhancement Factors Uplink and downlink cell spectral efficiency Uplink and downlink cell edge user throughput Peak data rate and system latency

• Under the condition of a 3GPP’s decision regarding the superiority of a 3GPP LTE-advanced to IMT-advanced requirement

◙ Non-quantitative Enhancement Factors Network scalability System inter-operability Enhanced mobility support Etc.


Multi-hop Relaying (1/2)

UE Peer-to-Peer Tx/RxUE Peer-to-Peer Tx/Rx

• Direct inter-UE connectivity • Autonomous ad-hoc network configuration and management

• Direct inter-UE connectivity • Autonomous ad-hoc network configuration and management

Relay Node Tx/RxRelay Node Tx/Rx

• Remote relay node Tx/Rx• L1 baseband processing and RRM• Coverage extension and throughput enhancement

• Remote relay node Tx/Rx• L1 baseband processing and RRM• Coverage extension and throughput enhancement

Conventional UE-eNodeB Tx/RxConventional UE-eNodeB Tx/Rx

• Conventional single-hop Tx/Rx between UE and eNodeB as a basic connection scheme• Conventional single-hop Tx/Rx between UE and eNodeB as a basic connection scheme

Wireless link connectioneNodeB

Relay Node

Relay Node


Multi-hop Relaying (2/2)

◙ Expected Trade-off

◙ Consideration Points Things to be further investigated

• Verification for practical benefits against system overhand & complexity• Smooth migration toward multi-hop relaying in addition to single-hop UE-eNB tra

nsmission & reception

Early-stage features of multi-hop relaying• Max. 2 hop relaying, i.e. single relay node between UE and eNodeB• Minimized impact on UE spec. • No support of UE peer-to-peer ad hoc transmission & reception

BenefitsBenefits DrawbacksDrawbacks

• Coverage extension• Throughput/capacity improvement• New killer application/service

• Coverage extension• Throughput/capacity improvement• New killer application/service

• System complication• Enlarged control/signaling overhead• Large change factors from the current 3GPP LTE spec

• System complication• Enlarged control/signaling overhead• Large change factors from the current 3GPP LTE spec

vs.


Bandwidth Assignment

◙ Consideration Points Backward compatible co-existence with LTE and LTE-advanced in IMT

carrier bands• SI or WI creation in 3GPP RAN for most carrier BW candidates given by WRC’07• Support of smooth migration from LTE toward LTE-advanced

Support of wider system bandwidth in LTE-advanced for higher data rate transmission

• Issue of the system BW of 20 or 40MHz on the system requirement documentation of IMT-advanced in ITU-R WP5D

• Probable situation of using a more extended system BW for higher data rate support

◙ Technical check points on implementation feasibility Potential of commercial-level RF filter

• Effective bandwidth range Potential of commercial-level ADC

• Sampling rate and quantization resolution Decoding complexity

• Channel decoding speed and required soft buffer size


Backward Compatible Co-existence of LTE and LTE-advanced

◙ Smooth Migration toward LTE-advanced on LTE Carriers

Further investigation for other possibilities including spectrum sharing

◙ Co-existence of LTE in Wider Carrier Bandwidth of LTE-advanced Baseline: FDM-based legacy zone support Technical consideration points

• Bandwidth camping of LTE system according to the bandwidth size of LTE-advanced

• Bandwidth aggregation capability of LTE-advanced

TDM-based allocation conceptTDM-based allocation concept

• Full transparency for UE Tx/Rx operation• Full bandwidth utilization • Large flexibility in new system design• Relatively weak power utilization on uplink cell-edge UE transmission

• Full transparency for UE Tx/Rx operation• Full bandwidth utilization • Large flexibility in new system design• Relatively weak power utilization on uplink cell-edge UE transmission

FDM-based allocation conceptFDM-based allocation concept

• Improved uplink cell-edge performance and/or coverage extension• Flexibility restriction in new system design• More guard band overhead and limited bandwidth utilization

• Improved uplink cell-edge performance and/or coverage extension• Flexibility restriction in new system design• More guard band overhead and limited bandwidth utilization

Time

Freq

LTELTE LTE-advancedLTE-advancedLTE Carrier LTELTE LTE-advancedLTE-advanced

Time

Freq

LTELTE

LTE-advancedLTE-advancedLTE

Carrier


Bandwidth Aggregation

◙ Motivation Higher data rate support Co-existence of LTE in wider carrier bandwidth of LTE-advanced

◙ Basic cases

◙ Consideration Points to Be Further Investigated Feasibility of simultaneous multiple Tx/Rx RF processes Maximum commercial-level RF BW capability Implementation cost and complexity for multiple physical layer processing Baseband decoding processing power

Case 1: Contiguous BW aggregation• Single or multiple Tx/Rx RF operation• Single or multiple physical layer processing

under the single MAC/RRC

Case 2: Separate BW aggregation• Multiple (or single) Tx/Rx RF operation• Multiple (or single) physical layer processing under

the single MAC/RRC


Enhanced MIMO (1/2)

◙ Main Motivation Improvement of DL/UL peak & cell spectral efficiency Improvement of DL/UL cell edge user throughput by applying an enhanced MIMO

transmission considering multi-cell situation

◙ Technology Candidates

eNodeB eNodeB

Relay Node Relay Node

UL SU-MIMO & TxD using mUL SU-MIMO & TxD using multiple RF chainsultiple RF chains

UL Cooperative MIMOUL Cooperative MIMO

Multi-cell MIMO: Type 1 Multi-cell MIMO: Type 1 (DL/UL Cooperative MIMO)(DL/UL Cooperative MIMO)

Multi-cell MIMO: Type 2Multi-cell MIMO: Type 2

(Adaptive Precoding/Beamforming)(Adaptive Precoding/Beamforming)

Wireless single-/multi-antenna transmission

Interfernece

Enhanced DL/UL MU-MIMOEnhanced DL/UL MU-MIMO


Enhanced MIMO (2/2)

Number of antennas in an eNodeB and a UE• Improvement of overall spectral efficiency• Careful consideration of the required target performance and the feasible UE cap

ability for LTE-advanced

Uplink single-user MIMO and transmit diversity• Improvement of UL peak & cell spectral efficiency• Issue points of UL SU-MIMO transmission scheme

– Antenna power balancing– Low and uniform per-antenna PAPR

• Cost effective design for DL/UL control signaling

Multi-cell MIMO• Improvement of DL/UL cell edge user throughput as well as cell spectral efficienc

y• Downlink/uplink cooperative MIMO (Type1): Multi-cell/site MIMO transmission an

d reception– Precoding based dual-cell unicast transmission – Enhanced MBMS transmission

• Adaptive precoding/beamformaing (Type 2): Evolved DL/UL MIMO transmission scheme for inter-cell interference mitigation

– Enhanced DL/UL single-user MIMO– Enhanced DL/UL multi-user MIMO


LTE Technical Items to Be Enhanced (1/2)

◙ Downlink/uplink Inter-cell Interference Management Motivation

• Significant improvement in downlink & uplink cell-edge user throughput and cell spectral efficiency

Related LTE items• DL/UL inter-cell interference coordination• DL/UL inter-cell power control mechanism

Consideration of relevant technologies• Multi-cell MIMO technologies• Dual-cell unicast transmission and fast cell-switching• Multi-hop relaying, etc.

◙ Self-organizing & -optimizing Network Motivation

• Largely probable situation of using small remote eNodeBs for coverage extension and throughput enhancement

• Mitigation of enlarged complexity/cost in deployment and network optimization for large number of eNodeBs

Consideration points• Rel.8 work item initiation coming along with home eNodeB• TBD whether further enhancement is necessary after investigating the specification results o

f current Rel.8 work item


LTE Technical Items to Be Enhanced (2/2)

◙ Multi-RAT Seamless Handover Motivation

• Enhanced requirement of inter-system interworking and its related mobility support

Consideration points• Extension level of inter-system interworking in addition to related Rel.8 work items

• Minimized impact on LTE-advanced specification


Thank you !!!

rev-080019 consideration on technical candidates for imt-advanced date: april 7 th ~8 th, 2008...

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