lte-advanced enhancements and future radio access toward 2020

NTT DOCOMO, INC., Copyright 2013, All rights reserved. 1

LTE-Advanced Enhancements and

Future Radio Access

Toward 2020 and Beyond

Takehiro Nakamura

NTT DOCOMO, INC.

Broadband World Forum 2013


Release of 3GPP specifications

1999 2000 2001 2002 2003 2004 2005

Release 99

Release 4

Release 5

Release 6

1.28Mcps TDD

HSDPA

W-CDMA

HSUPA, MBMS

2006 2007 2008 2009

Release 7 HSPA+ (MIMO, HOM etc.)

Release 8

2010 2011

LTE

Release 9

Release 10

Minor LTE enhancements

2012 2013

Release 11

ITU-R M.1457 IMT-2000 Recommendation

LTE-Advanced ITU-R M.2012 IMT-Advanced

Recommendation

2014

Release 12

To be

frozen in

June 2014


3GPP LTE Release 12


• Study Item

– Small Cell Enhancement

– 3D-channel model for Elevation Beamforming and Full Dimension-MIMO

– Network-Assisted Interference Cancellation and Suppression

– Device to Device (D2D) Proximity Services

– Coordination Multi-Point (CoMP) with non-ideal backhaul

• Work Item

– Further enhancements to TDD for DL/UL Interference Management and

Traffic Adaptation (eIMTA)

– Further DL MIMO Enhancement

– Low cost & enhanced coverage MTC UE

– TDD-FDD Joint Operation

– Coverage Enhancements

Key Features in Release 12 Physical layer aspects


Small Cell Enhancements (SCE) -PHY aspects-

• Objective – Spectrum efficiency improvements

• Higher order modulation (e.g., 256QAM)

• Overhead reduction, control signaling enhancement

– Efficient small cell operation • Interference avoidance and coordination

• Small cell ON/OFF, load balancing/shifting

• Efficient small cell discovery

• Radio Interface-based sync.

– Physical layer study for higher-layer aspects • Dual connectivity to macro and small cell

layers

• Mobility enhancements

• DOCOMO’s view – Consider dense small cell deployment

with higher frequency band – Propose

• Phantom cell concept (Dual connectivity)

• Efficient discovery mechanism

• etc.

Best effort

services Realtime services

(e.g., VoLTE)

Control functionalities

256QAM

Replace RS by data

RS

Small cell OFF

Efficient discovery

Sync and/or coordination

among small cells


MIMO Enhancements

Rel-10 MIMO

2D MIMO enhancement

Elevation beam forming Full dimension-MIMO

• Max. 8-Tx

Beam gain and interference

reduction using 3D beam

•Max. 8-Tx (Max. 4-Tx for FDD)

•Achieves beamforming in azimuth angle

• More than 8-Tx (e.g., 16, 32, …)

• Higher freq. (e.g., 3.5 GHz-)

Progressive capacity enhancement

• 4-Tx codebook enhancement

• Feedback enhancement for MU-

MIMO

Rel-12 MIMO

3D MIMO using active antenna system

N

M

NxM antennas

(Using higher

freq.)

Study of 3D channel model (3D UE distribution, 3D pathloss, fast fading, etc

Optimization for

realistic environment

Beamforming in

azimuth/elevation angle

Enhancement of the

number of antennas

•DOCOMO’s view – Focus on

• Full dimension MIMO with higher frequency band


NW-Assisted Interference Cancellation and Suppression

• Study on a variety of receiver types and need of interference information – Interference suppression: Enhancement of Rel-11 receiver

– Interference cancellation: Subtraction of interference replica from received signal, e.g., SIC

Rel. 11 Advanced receiver Rel. 12 Advanced receiver

Target for receiver Interference limited areas,

i.e., cell edge

All areas including cell edge

Inter-UE interference for

MU-MIMO

■Target for Advanced receiver

Severer interference

for other scenarios

Inter-cell

interference

at cell edge

•DOCOMO’s view – Propose/Investigate

• NW-assisted signaling

• Receiver performance


TDD-FDD Joint Operation

FDD TDD Freq. UL DL UL/DL

eNB

UL/DL

UL/DL

UL/DL

PCell

SCell

SCell

SCell

SCell

• Objective – TDD-FDD carrier aggregation

• Either TDD or FDD as Pcell

– TDD-FDD joint operation (e.g., multi-stream aggregation, dual mode UE)

• Identify deployment scenarios of joint operation on FDD and TDD spectrum, and network/UE requirement

• DOCOMO’s view – Very interested in TDD-FDD carrier

aggregation

– Consider FDD Pcell (Macro cell) and TDD Scell (many Small cells) with higher frequency band

– Propose • TDD-FDD carrier aggregation

mechanism


Device to Device (D2D) proximity service

• Objective

– Commercial use with NW coverage

– Public safety/critical communication with/without NW coverage

– Two kinds of technical topics

• D2D discovery

• D2D communication

Disaster, Terror

Outside NW Within NW coverage

D2D

Current NW

Internet

Discovery Discovery

+ Communication Streaming, Mail, etc.

Internet

Advertise, ITS, etc.

Comm. for public safety

Required both

for public

safety & non-

public safety

With NW

coverage

Without NW

coverage

Discovery

Commu-

nication

Public safety

only

Required at

least for public

safety

Public safety only

•DOCOMO’s view – Interested in commercial discovery

– Propose/Investigate • D2D discovery mechanism


eIMTA* (Dynamic TDD)

• Objective

– TDD UL-DL reconfiguration for traffic adaptation

• Reconfiguration mechanism

• HARQ scheme

– Interference mitigation with TDD

UL-DL reconfiguration

• UL power control

• DOCOMO’s view – Interested in this topic with

higher frequency band – Propose/Investigate

• Interference mitigatation scheme

• HARQ mechanism

Cell 1

Cell 2

Scheme 1

Scheme 2

Scheme 3

Scheme 4

Interference mitigation schemes

Cell clustering Scheduling

enhancement

Interference mitigation

based on (F)eICIC Interference suppressing

and mitigation

* eIMTA: Further enhancements to LTE TDD

for DL-UL interference management and traffic adaptation

DL-to-UL interference

UL-to-DL interference


Future Radio Access (5G)

- Toward 2020 and Beyond -


Network/Communication Society

in 2020 and Beyond Everything Connected

by Wireless

Extension/enrichment

of wireless services Deliver rich contents in real-time & ensure safety Monitor/collect information & control devices

Multiple personal

devices

Interaction across

multiple devices

Transportation

(Car/Bus/Train)

Consumer

electronics Watch/jewelry/cloth

s

House Sensors Cloud computing

Video streaming New types of

terminal/HI

Healthcare Education

Safety and lifeline system

Smart power grid

Agriculture and farming

Factory automation

Weather/Environment

Remote operation using

personal terminal

Entertainment, Navigation

Traffic information

All kinds of services supported

by the mobile personal cloud

Remote control of

facilities

House security

4K/8K video resolutions

Video on newspapers

Background video

4K

Glasses/Touch internet

Human interface

and healtchcare

sensors

Remote health

check &

counseling

Distance (remote) learning

Any lesson anywhere/anytime

Prevention of accidents

Robustness to disasters


FRA concept and requirements

Various requirements for network/communication

society in 2020 and beyond

Future

Radio

Access

Support for traffic

explosion

QoE for various

applications

Massive device

connectivity

Intelligent network

with low cost & high

robustness

• 1000x capacity/km2 • 10-100x data rates

• Reduced latency to < 1ms • Support of high mobility

• Terminal battery saving

• 100x more connected devices • Lower overhead incl. reduced control signaling

• Enhanced connectivity, e.g., deep inhouse

• Very small/light BS with energy saving

• Reduced network cost incl. backhaul

• Efficient support for diverse environments

incl. emergency cases

FRA will provide a total solution to satisfy the requirements


Evolution paths for FRA P

erf

orm

ance

~2015

Rel-10/11

Rel-8/9 Pico/Femto

LTE

LTE-Advanced

Rel-12/13

Potential

New RAT

Big gain

~2020 Year

Future Radio Access

(= Future IMT = 5G?)

Rel-14/15,…

• Further LTE enhancements – Macro-assisted small cell enhancement

(Phantom cell) – Further general LTE enhancements

• Potential new RAT – Should prioritize the achievement of more

big gains over backward compatibility – Consider new spectrum allocations of

WRC-15 and beyond – Some technical components may be

applied to further LTE enhancements

Macro-assisted small cell enhancement

(Phantom cell)

Further LTE

enhancements

CA/eICIC/CoMP

for HetNet WRC-15 WRC-18/19


Directions of evolution: “The Cube”

Spectrum extension

Network densification

Required performance

Spectrum efficiency

Current capacity

New cellular concept for cost/energy-

efficient dense deployments

Non-orthogonal multiple access

Study for new interference scenarios

Dense urban

Shopping mall

Hotspot

Cellular network assists

local area radio access

Efficient use of higher spectrum bands

Tx-Rx cooperative access technologies

A set of radio access technologies is required

to satisfy future requirements

Existing cellular bands Higher/wider frequency bands

Frequency

Very wide Super wide

Controller

TRx

TRx

TRx

TRx

TRx

TRx

TRx

TRx

3D/Massive MIMO,

Advanced receiver

WiFi

Traffic offloading


Combined usage of lower and higher frequency bands Higher frequency bands become useful and beneficial!

FRA technical concept

Existing cellular bands (high power density for coverage)

Higher frequency bands (wider bandwidth for high data rate)

Frequency

Very wide

(e.g. > 3GHz)

Super wide

(e.g. > 10GHz)

FRA technical concept Further cellular

enhancements

No coverage issue any

more

Can provide very high

throughput using wider

bandwidth

Big offloading gain from

existing cellular bands

Exploitation of higher

frequency bands


FRA Real-time Simulator

The potential performance gains of applying key FRA

technologies are demonstrated using FRA real-time simulator.

Demo Scenario

Spectrum extension x NW densification

• Efficient exploitation of higher frequency bands using small cells

Key technology for small cells

• Massive MIMO

Key technology for macro cells

• Non-orthogonal Multiple Access (NOMA)


Macro @ 2GHz (20MHz) + 12 small cells @ 3.5GHz (100MHz)

w/ Raytracing @ Shinjuku, Tokyo

FRA Real-Time Simulator


FRA Real-Time Simulator Macro @ 2GHz (20MHz) + 12 small cells @ 10 GHz (400MHz)



Macro @ 2GHz (20MHz) + 12 small cells @ 20 GHz (1GHz)




Macro @ 2GHz (20MHz) + 12 small cells @ 20 GHz (1GHz) + Massive MIMO



lte-advanced enhancements and future radio access toward 2020

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cell interference

cell edgeseverer interference

lte tdd

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tdd scell

interference reduction

cell edgetarget

tdd spectrum