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
May 07, 2015
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
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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
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3GPP LTE Release 12
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• 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
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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
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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
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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
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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
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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
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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
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Future Radio Access (5G)
- Toward 2020 and Beyond -
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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
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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
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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
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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
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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
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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)
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Macro @ 2GHz (20MHz) + 12 small cells @ 3.5GHz (100MHz)
w/ Raytracing @ Shinjuku, Tokyo
FRA Real-Time Simulator
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FRA Real-Time Simulator Macro @ 2GHz (20MHz) + 12 small cells @ 10 GHz (400MHz)
w/ Raytracing @ Shinjuku, Tokyo
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Macro @ 2GHz (20MHz) + 12 small cells @ 20 GHz (1GHz)
w/ Raytracing @ Shinjuku, Tokyo
FRA Real-Time Simulator
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Macro @ 2GHz (20MHz) + 12 small cells @ 20 GHz (1GHz) + Massive MIMO
w/ Raytracing @ Shinjuku, Tokyo
FRA Real-Time Simulator
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