DoCoMo Beyond Release 12 LTEWS 250613.Php4

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

RAN Evolution

Beyond Release 12

Takehiro Nakamura

NTT DOCOMO, INC.

LTE World Summit 2013


FRA concept

Future Radio

Access

Massive device

connectivity

Support for traffic

explosion

QoE for various

applications

Intelligent network with

low cost & high robustness

Future Radio Access (FRA) will provide a total solution

to satisfy the requirements by future drivers

Beyond 500x in 10 years Gbps-experience data rate,

Reduced latency,

Battery saving

Reduced control signaling,

More simultaneous pipes

Support of diverse environments

(small cells & higher frequency bands),

Energy saving


Capacity

Higher system capacity:

Report ITU-R M.2243 (IMT.UPDATE): 1530 times traffic growth is envisioned between 2010 and 2015

Mobile data traffic is continuously growing over DOCOMO network

Approx. 1.6 times per year (2004 2009)

Approx. 2 times per year (2010 2011)

Approx. 12 times traffic growth is envisioned between 2011 and 2015

Mobile data traffic is

expected to grow to

x500~x1000 in 10 years

(2010 2020)

Traffic growth forecast

Tra

ffic

volu

me

2010 2011 2015

~ 2x

Fiscal Year

~ 12x

The main drivers are smartphones, video services and high-speed data access


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


Evolution paths for FRA P

erf

orm

ance

~2015

Rel-10/11

Rel-8/9 Pico/Femto

LTE

LTE-Advanced

LTE-B

Rel-12/13

WRC-15

Potential

New RAT

Big gain

~2020 Year

Future Radio Access

LTE-C

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


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)


Future cellular

enhancements

New RAT for

higher frequencies

No coverage issue any more

Can provide very high throughput using wider

bandwidth

Big offloading gain from existing cellular bands


Phantom cell concept

Proposed macro-assisted small cell Phantom cell

Split of C-plane and U-plane between macro & small cells in different bands

Existing

cellular bands

Higher

frequency bands

Macro cell

Phantom cell

C-plane: Macro cell maintains

good connectivity and mobility

using lower frequency bands

U-plane: Small cell provides higher

throughput and more flexible/cost-

energy efficient operations using

higher/wider frequency bands (RRC: Radio Resource Control)


Massive MIMO BF gain

Beamforming (BF) gain with massive antenna elements

Massive MIMO

Massive MIMO in higher frequency bands Compensation of increased path loss & Improved spectrum efficiency

Improved coverage and spectrum

efficiency for super dense small cells

in higher freqeuncy bands

2GHz

min

L

G

Increasing number of antenna elements by X

1) Increase of BF gain by X

2) Decrease of BF width by 1/X

4GHz

min /2

2G

L

(/2)/2 /2

Distance between antenna

elements /2 reduced by half doubles the number of antenna

elements


NOMA utilizes path loss difference

for efficient user multiplexing

Non-orthogonal multiple access (NOMA) More efficient multiple access scheme

Non-Orthogonal Multiple Access (NOMA)

Why NOMA? Multiple access using interference cancellation itself is very old technology (for uplink in particular)

Evolution of device processing capabilities for interference cancellation

Moores law: 100x processing power after 10 years

In OFDMA, frequency-domain signal processing becomes possible

Exploitation of path loss difference among users

Multi-path fading was exploited by OFDMA,

but path loss still needs to be further exploited

W-CDMA LTE FRA

Radio resource

allocation

Non-orthogonal

(CDMA)

Orthogonal

(OFDMA)

Orthogonal (OFDMA)

+ Superposition/Cancellation

(NOMA)

Link adaptation Fast TPC (TPC: Transmission Power Control)

AMC (AMC: Adaptive Modulation & Coding)

MUPA/AMC (MUPA: Multi-User Power Allocation)

Multiple access

image

f f f

Orthogonal between users Non-orthogonal assisted

by power control

Superposition & interference cancellation

More details on NOMA concept and initial results are presented in this WS.


FRA real-time simulator

The potential perfomance 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 Cell Only Macro + 12 small Cells, 100 MHz [email protected] GHz



100 MHz [email protected] GHz 200 MHz BW@5 GHz 400 MHz BW@10 GHz



400 MHz BW@10 GHz 600 MHz BW@20 GHz With Massive MIMO


Summary

We presented our views on requirements and potential key techologies for Future Radio Access (FRA):

Macro-assisted small cell, i.e., Phantom cell, and Massive MIMO are promising approaches for higher/wider frequency

bands towards the long-term future

Non-orthogonal multiple access (NOMA) is a promising technology for future cellular enhancements


Future cellular

enhancements

New RAT for

higher frequencies

Documents

DoCoMo Beyond Release 12 LTEWS 250613.Php4