LTE-Advanced Enhancements and Future Radio Access Toward 2020

1. Broadband World Forum 2013
LTE-Advanced Enhancements and
Future Radio Access
Toward 2020 and Beyond
Takehiro Nakamura
NTT DOCOMO, INC.
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2. Release of 3GPP specifications
1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014
Release 99
W-CDMA
Release 4
1.28Mcps TDD
Release 5
HSDPA
Release 6
HSUPA, MBMS
Release 7
ITU-R M.1457
IMT-2000 Recommendation
ITU-R M.2012
IMT-Advanced
Recommendation
HSPA+ (MIMO, HOM etc.)
Release 8
LTE
Release 9
Minor LTE
enhancements
Release 10
LTE-Advanced
Release 11
Release 12
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To be
frozen in
June 2014 2

3. 3GPP LTE Release 12
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4. Key Features in Release 12
Physical layer aspects
• 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
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5. Small Cell Enhancements (SCE)
-PHY aspects• Objective
– Spectrum efficiency improvements
• Higher order modulation (e.g., 256QAM)
• Overhead reduction, control signaling
enhancement
RS
– Efficient small cell operation
•
•
•
•
Interference avoidance and coordination
Small cell ON/OFF, load balancing/shifting
Efficient small cell discovery
Radio Interface-based sync.
256QAM
Replace RS by data
Efficient discovery
– Physical layer study for higher-layer aspects
• Dual connectivity to macro and small cell
layers
• Mobility enhancements
Small cell OFF Sync and/or coordination
among small cells
• DOCOMO’s view
– Consider dense small cell deployment
with higher frequency band
Control functionalities
– Propose
• Phantom cell concept (Dual connectivity)
• Efficient discovery mechanism
• etc.
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Realtime services
(e.g., VoLTE)
Best effort
services
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6. MIMO Enhancements
Rel-10 MIMO
• Max. 8-Tx (Max. 4-Tx for FDD)
• Achieves beamforming in azimuth angle
Optimization for
realistic environment
Beamforming in
azimuth/elevation angle
Enhancement of the
number of antennas
Rel-12 MIMO
2D MIMO enhancement
3D MIMO using active antenna system
Study of 3D channel model (3D UE distribution, 3D pathloss, fast fading, etc
Elevation beam forming
Full dimension-MIMO
NxM antennas
(Using higher
freq.)
N
M
• 4-Tx codebook enhancement
• Feedback enhancement for MUMIMO
• Max. 8-Tx
 Beam gain and interference
reduction using 3D beam
• More than 8-Tx (e.g., 16, 32, …)
• Higher freq. (e.g., 3.5 GHz-)
Progressive capacity enhancement
•DOCOMO’s view
– Focus on
• Full dimension MIMO with higher frequency band
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7. NW-Assisted Interference
Cancellation and Suppression
Rel. 11 Advanced receiver
Target for receiver
Rel. 12 Advanced receiver
Interference limited areas,
i.e., cell edge
All areas including cell edge
■Target for Advanced receiver
Inter-UE interference for
MU-MIMO
•
Inter-cell
interference
at cell edge
Severer interference
for other scenarios
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
•DOCOMO’s view
– Propose/Investigate
• NW-assisted signaling
• Receiver performance
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8. TDD-FDD Joint Operation
• Objective
– TDD-FDD carrier aggregation
• Either TDD or FDD as Pcell
– TDD-FDD joint operation (e.g., multistream aggregation, dual mode UE)
• Identify deployment scenarios of joint
operation on FDD and TDD
spectrum, and network/UE
requirement
eNB
FDD
UL
DL
• 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
TDD
UL/DL
Freq.
SCell
PCell
UL/DL
SCell
UL/DL
SCell
UL/DL
SCell
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9. Device to Device (D2D) proximity service
• Objective
With NW
coverage
Discovery
Required both
for public
safety & nonpublic safety
Public safety
only
Communication
– Commercial use with NW coverage
– Public safety/critical communication
with/without NW coverage
– Two kinds of technical topics
Without NW
coverage
Required at
least for public
safety
Public safety only
• D2D discovery
• D2D communication
Current NW
Within NW coverage
Internet
Outside NW
Internet
Disaster, Terror
D2D
Streaming,
Mail, etc.
Discovery
Advertise, Discovery
Comm. for
+ Communication public safety
ITS, etc.
•DOCOMO’s view
– Interested in commercial discovery
– Propose/Investigate
• D2D discovery mechanism
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10. eIMTA* (Dynamic TDD)
* eIMTA: Further enhancements to LTE TDD
for DL-UL interference management and traffic adaptation
• Objective
DL-to-UL interference
– TDD UL-DL reconfiguration for
traffic adaptation
• Reconfiguration mechanism
• HARQ scheme
Cell 2
Cell 1
UL-to-DL interference
– 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
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 Interference mitigation schemes
Scheme 1
Scheme 2
Cell clustering
Scheduling
enhancement
Scheme 3
Scheme 4
Interference mitigation
based on (F)eICIC
Interference suppressing
and mitigation
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11. Future Radio Access (5G)
- Toward 2020 and Beyond -
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12. Network/Communication Society
in 2020 and Beyond
Extension/enrichment
of wireless services
Everything Connected
by Wireless
Monitor/collect information & control devices
Multiple personal
devices
Transportation
(Car/Bus/Train)
Deliver rich contents in real-time & ensure safety
Video streaming
New types of
terminal/HI
4K
Interaction across
multiple devices
Consumer
electronics
Entertainment, Navigation
Traffic information
Watch/jewelry/cloth
s
4K/8K video resolutions
Video on newspapers
Background video
Healthcare
Human interface
and healtchcare
sensors
Remote operation using
personal terminal
Education
Remote health
check &
counseling
House
Sensors
Cloud computing
Remote control of
facilities
House security
Smart power grid
Agriculture and farming
Factory automation
Weather/Environment
All kinds of services supported
by the mobile personal cloud
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Glasses/Touch internet
Distance (remote) learning
Any lesson anywhere/anytime
Safety and lifeline system
Prevention of accidents
Robustness to disasters
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13. FRA concept and requirements
Various requirements for network/communication
society in 2020 and beyond
Support for traffic
explosion
• 1000x capacity/km2
QoE for various
applications
Future
Radio
Access
Massive device
connectivity
• 100x more connected devices
• Lower overhead incl. reduced control signaling
• Enhanced connectivity, e.g., deep inhouse
• 10-100x data rates
• Reduced latency to < 1ms
• Support of high mobility
• Terminal battery saving
Intelligent network
with low cost & high
robustness
• 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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14. Evolution paths for FRA
• Further LTE enhancements
– Macro-assisted small cell enhancement
(Phantom cell)
– Further general LTE enhancements
• Potential new RAT
Performance
– 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
LTE-Advanced
LTE
Macro-assisted
small cell enhancement
(Phantom cell)
Rel-12/13
Rel-10/11
Rel-8/9
Pico/Femto
CA/eICIC/CoMP
for HetNet
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WRC-15
~2015
Future Radio Access
(= Future IMT = 5G?)
Potential
New RAT
Big gain
Rel-14/15,…
Further LTE
enhancements
WRC-18/19
~2020
Year
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15. Directions of evolution: “The Cube”
A set of radio access technologies is required
to satisfy future requirements
Required performance
Spectrum efficiency
Traffic offloading
TRx
TRx
TRx
WiFi
TRx
TRx
TRx
TRx
TRx
Non-orthogonal multiple access
Controller
3D/Massive MIMO,
Advanced receiver
Network densification
Current
capacity
Hotspot Dense urban
Shopping mall
Study for new interference scenarios
Tx-Rx cooperative access technologies
Spectrum extension
Existing cellular bands
Cellular network assists
local area radio access
Higher/wider frequency bands
Very wide
Super wide
New cellular concept for cost/energyefficient dense deployments
Frequency
Efficient use of higher spectrum bands
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16. FRA technical concept
Combined usage of lower and higher frequency bands
 Higher frequency bands become useful and beneficial!
Existing cellular bands
Higher frequency bands
(high power density for coverage)
(wider bandwidth for high data rate)
Very wide
(e.g. > 3GHz)
Super wide
(e.g. > 10GHz)
 No coverage issue any
more
 Can provide very high
throughput using wider
bandwidth
 Big offloading gain from
existing cellular bands
Frequency
FRA technical concept
Further cellular
enhancements
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Exploitation of higher
frequency bands
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17. 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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18. FRA Real-Time Simulator
Macro @ 2GHz (20MHz) + 12 small cells @ 3.5GHz (100MHz)
w/ Raytracing @ Shinjuku, Tokyo
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19. FRA Real-Time Simulator
Macro @ 2GHz (20MHz) + 12 small cells @ 10 GHz (400MHz)
w/ Raytracing @ Shinjuku, Tokyo
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20. FRA Real-Time Simulator
Macro @ 2GHz (20MHz) + 12 small cells @ 20 GHz (1GHz)
w/ Raytracing @ Shinjuku, Tokyo
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21. FRA Real-Time Simulator
Macro @ 2GHz (20MHz) + 12 small cells @ 20 GHz (1GHz) + Massive MIMO
w/ Raytracing @ Shinjuku, Tokyo
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22. NTT DOCOMO, INC., Copyright 2013, All rights reserved.
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