OFDMA and 4G Technologies - ABES Engineering...
Transcript of OFDMA and 4G Technologies - ABES Engineering...
OFDMA and 4G Technologies Long Term Evoloution-Advanced
February, 2013
Presentation
By
Asit Kadayan, Director, National Telecom Institute (DoT)
For Conference at BABES, Ghaziabad
OFDMA and 4G
Fixed subscribers - 30.79 Million
Mobile - 864.72 Million
Gross - 895.51 Million (Wireless+Wireline)
Total Tele density - 70.82%
Rural Tele density - 39.04%
Urban Tele density - 143.48%
Broadband Subscription – 14.98 Million
Growth Rate /Month - 0.1 Million
Phenomenal Growth: Indian Scenario: Dec 2012
-0.27% per month
-2.79% per month
Applications & Services
OFDMA and 4G
Education •Virtual School
•On-line Laboratories
•On-line Library
•On-line Training
•Remote Consultation
Telemetric Services •Machine-Machine
Services
•Location Based Tracking
•Navigation Assistance
•Travel Information
•Fleet Management
•Remote Diagnostics
Public Services •Public Elections/Voting
•Public Information
•Help
•Broadcast Services
•Yellow Pages
Financial Services •On-line banking
•Universal SIM & Credit Card
•Home Shopping
•Stock Quotes Communications •Video Telephony
•Video Conferencing
•Speech
•Announcing Services
•SMS
•Electronic Postcards
Information
•Intelligent Search and Filtering
agents
•Internet Surfing
•On-line media
•On-line translation
•Local information
•Booking & Reservation
•News
Office Information •Virtual Working Groups
•Tele-working
•Schedule Synchronisation
Special Services •Security Service
•Hotline
•Tele-medecine
Leisure •Virtual Book Store
•Music on Demand
•Games on Demand
•Video-clips
•Virtual Sight Seeing
•Lottery Services
Mobile global data traffic
The growing adoption of
data services has become
the major source of
traffic since 2010
On the Analysis Masson
forecasts , mobile traffic
is expected to grow at a
CAGR (Compound
annual growth rate) of
42% to reach 28 000 PB
per year in 2015.
Source: ITU-R M.2243 Report
Estimates data traffic based on multiple sources
OFDMA and 4G
Mobile global data traffic
The ITU-R M. 2243 Report concludes
“The data traffic (in year 2010) was more than 5 times greater than some of the estimates for Report ITU-R M. 2072. “
“Actual traffic being experienced by some operators in year 2011 was even greater than some of the 2020 forecasts given in Report ITU-R M.2072.[…].” Source: ITU-R M. 2243 Report
Comparison of ITU-R M.2072 with Current Data
OFDMA and 4G
Factors impacting traffic forecast
Diversity of devices
Tablet generates 500 times as
much data traffic as a basic mobile
phone
Smartphones generate, on
average, around 50 times more
data per month than a basic phone
Average modem/dongle use,
with laptop users generating as
much as 1300 times that of a
“standard” 3G phone
0
5,000
10,000
15,000
20,000
25,000
30,000
2008 2009 2010 2011 2012 2013 2014 2015T
raff
ic (
Pe
tab
yte
s p
er
ye
ar)
Smartphone Voicephone
Tablet, eReader, Gaming console Laptop
M2M ITU-R M.2072 forecast
Mobile traffic (PB per year) by device type
Source: ITU, Analysys Mason
Mobile data usage is heavily device-dependent
OFDMA and 4G
Factors impacting traffic forecast
Number of devices
2020
12 Billion Mobile Connected
Devices
2011
6 Billion Mobile Connected Devices
Source: Machina
Mobile world has reached another milestone with Internet becoming
increasingly mobile. Based on industry information, estimates that the
number of mobile subscription will reach 9 billion end of 2017
Spectrum is a key resource/element for Mobile Broadband development
OFDMA and 4G
OFDMA and 4G
Wireless Access Evolution
Broadband
New Services
Efficiency
Broadband
Subscribers
Voice
Coverage
Mobility
Voice Quality
Portability
Capacity
Broadband
Network
Simplification
Cost of
Ownership
OFDMA and 4G
Evolution of Wireless Mobile Communication
AMPS
(America)
TACS, NMT
(Europe)
IS-54
GSM
IS-95A CDMA200095B
EVDO
EVDV
EVDO
RevA
EVDO
RevBUMB
WCDMA HSDPA HSPA+ LTE
CT-2
pager
GPRS
EDGE
WiMAX
wave 1
WiMAX
wave 2
TD-SCDMA
(China)
4G
1990 1995 2000 2005
1G (analog)2G (digital)
3G~3.9G (high speed data)
4G (very high speed data)
voice
voice
Voice, 14.4k
Voice, 14.4k
voice
Voice, 14.4k
Data, 56k
한 한 한 한 한 한 한 한 (2007한 한 한 )
Voice, 384k
Data only, 2.4M/150k
Voice, 153k
Voice, 3.2M/1.8M
3.2M/1.8M
14.4M/5M
14.7M/5.4M ~200M
~200M
Voice, 384k
20M/5M 40M/10M100M~1G
56k
384k
number
High Data Rates in Mobile Networks
Fundamental Constraints
– Shanon’s Limit C=BW log2 (1+S/N).
Min {Eb/No}=(2γ-1)/γ where γ=R/BW
– Power Limited Region
– Bandwidth Limited Region
High Data Rates in noise-limited Region
High Data Rates in Interference-limited region
Higher Order Modulation (HOM)
HOM with Channel Coding
– Variations in Instantaneous TX Power
OFDMA and 4G
5 MHz carrier
4x4 MIMO
Downlink
3.6 Mbps
14 Mbps
21 Mbps 28 Mbps
42 Mbps
15 codes
2x2 MIMO 64QAM
Both
5 MHz carrier 4x4 MIMO
2007
2008
2009
eHSPA
158 Mbps
Uplink
0.384 Mbps
1.4 Mbps
5.8 Mbps
12 Mbps
HSPA
on the uplink
2 ms TTI
16QAM
52 Mbps 20 MHz carrier
2x2 MIMO
20 MHz carrier
1x2 MIMO
80 Mbps
LTE
(Q3 2009)
23 Mbps LTE
(Q3 2009)
eHSPA
HSPA
Evolution to even higher speeds and lower latency
2006
OFDMA and 4G
Adaptive Modulation and Coding (AMC)
Adaptive Modulation
Throughput
Received SINR
64-QAM
16-QAM
8-PSK
QPSK
QPSK 8-PSK 16-QAM 64-QAM
Adaptively select the modulation type depending on the received SINR
OFDMA and 4G
Adaptive Modulation and Coding (AMC)
Adaptive Modulation and Coding Throughput
Received SINR
64-QAM
16-QAM
8-PSK
QPSK/R=1/5
QPSK 8-PSK 16-QAM 64-QAM
Adaptively select the modulation type and coding rate depending on the received SINR
QPSK/R=2/5
OFDMA and 4G
Wide Bandwidth including Multi-Carrier
Complexity of equipment at BS and UE
– Sampling rate, A2D, D2A, DSP
Coherent BW
– Time dispersion
Coherent Time
– Doppler Effect
Receiver-side Equalization
OFDMA PAPR
SC-OFDM
OFDMA and 4G
OFDM- High Data Rate vs. Lower Symbol Rate
Data rate = 54 Mbits/sec
@ ¾ coding = 72 Mbits/sec
@ 64QAM = 12 MSym/sec
SCM: OFDM:
Data rate = 54 Mbits/sec
@ ¾ coding = 72 Mbits/sec
@ 48 carriers= 1.5 Mbits/sec
@ 64QAM = 250 kSym/sec
1 Sym = .083 usec
1 Sym = 4.0 usec
This is a sample;
FFT(64 samples) gives
64 freq bins (48 carriers
+ 4 pilots + 12 zeros)
This is a
symbol
= 6 bits
OFDM – Orthogonals Signals
Signal structure: Many closely spaced individual carriers
Carrier spacing insures orthogonality, i.e.
Carrier spectrum = Sin (x)/X shape
Carrier placement = Sin (x)/X nulls
BW = #sub-Carriers x
Spacing
Advantages of OFDM: Excellent immunity to multi-path distortion
Excellent tolerance of single frequency
interferer
64QAM 16QAM QPSK
LTE-Downlink mapping
P-SCH - Primary Synchronization Channel S-SCH - Secondary Synchronization Channel
PBCH - Physical Broadcast Channel
PDCCH -Physical Downlink Control Channel
PDSCH - Physical Downlink Shared Channel
Reference Signal – (Pilot)
LTE-Resource grid
6 or 7 OFDM symbols in 1 slot
Subcarrier spacing = 15 kHz
Block of 12 SCs in 1 slot = 1 RB – 0.5 ms x 180 kHz
– Smallest unit of allocation
6 or 7 OFDM symbols
One downlink slot, Tslot
:
:
Transmission BW
Resource block
Resource element
l=0 l=6
12 subcarriers
OFDM symbols (= 7 OFDM symbols @ Normal CP)
The Cyclic Prefix is created by
prepending each symbol with a
copy of the end of the symbol
160 2048 144 2048 144 2048 144 2048 144 2048 144 2048 144 2048 (x Ts)
1 frame = 10 sub-frames
= 10 ms
1 sub-frame = 2 slots
= 1 ms
1 slot = 15360 Ts
= 0.5 ms
0 1 2 3 4 5 6 et
c.
CP CP CP CP CP CP CP
P-SCH - Primary Synchronization Channel S-SCH - Secondary Synchronization Channel
PBCH - Physical Broadcast Channel
PDCCH -Physical Downlink Control Channel
PDSCH - Physical Downlink Shared Channel
Reference Signal – (Pilot)
DL
symbN
#0 #1 #8 #2 #3 #4 #5 #6 #7 #9 #10 #11 #12 #19 #13 #14 #15 #16 #17 #18
LTE-Downlink frame structure
1 0 2 3 4 5 6 1 0 2 3 4 5 6
OFDMA and 4G
100 MHz BW
8x MIMO
20+20 MHz
64 QAM UL
MU-MIMO (DL)
4xMIMO
MU-MIMO (UL)
OFDM
64/16 QAM DL/UL
2x MIMO
Capacity and Performance roadmap
20+20 MHz BW
64 QAM UL
MU-MIMO (DL)
4xMIMO
MU-MIMO (UL)
OFDM
64/16 QAM DL/UL
2x MIMO
4x MIMO
MU-MIMO (UL)
OFDM
64/16 QAM DL/UL
2x MIMO
OFDM
64/16 QAM DL/UL
2x MIMO
300 Mbps
75 Mbps
150 Mbps
50 Mbps
600 Mbps
150 Mbps
1000 Mbps
500 Mbps
Terminal capabilites
LTE brings excellent user and network experience
Spectral efficiency
Global trend towards IMT
systems
IMT / IMT-Advanced family
Provides a global ecosystem
with inherent mobility
Dramatically improves speed
and latency
OFDMA and 4G
Multiple Antenna Features
Generalized spatial multiplexing
– With M base station antennas, it is
possible to transmit up to M spatial
streams.
– Generalized spatial multiplexing
distributes M streams optimally on a
frame-by-frame basis.
Performance will be better than
SU-MIMO or MU-MIMO alone
Adapts transmission strategy for
each mobile individually based on
the number of antennas
OFDMA and 4G
OFDMA and 4G
Key LTE radio access features
LTE radio access
– Downlink: OFDM
– Uplink: SC-FDMA
Advanced antenna solutions
– Diversity
– Beam-forming
– Multi-layer transmission (MIMO)
Spectrum flexibility
– Flexible bandwidth
– New and existing bands
– Duplex flexibility: FDD and TDD 20 MHz 1.4 MHz
SC-FDMA
OFDMA
TX TX
LTE-Advanced Technologies
LTE-Advanced Key Technologies
New
technologies
CoMP (Coordinated Multipoint
Transmission/Reception)
-Cell edge throughput improvement
-High data rate coverage extension
Relay -Coverage hole elimination
-High data rate coverage extension
-Replacement of wire backhaul
Bandwidth Extension -Up-to 100MHz transmission bandwidth
-Utilization of noncontiguous spectrum segments
LTE
enhancement
technologies
MIMO -Increase of Peak data rate and cell throughput
-DL : 8x8 MIMO
-UL : 4x4 MIMO
UL SC-FDMA
enhancement
-Allocation of non-contiguous frequency blocks
:Increase of cell throughput
-Transmission on separate carriers for control and data channels
OFDMA and 4G
CoMP (COordinated MultiPoint Transmission/Reception)
Coordinated multipoint Tx/Rx(COMP)
– Coordinate the transmission and reception of signal from/to one UE in several geographically separated points.
– What to achieve?
Reduced/controlled inter-cell interference
Improved signal strength in donwlink and uplink
BS
BS
MS
MS
Network backhaul
w11S1+w12S2
h11h12
h21
h22
CoMP operation
Precoding
Channel info
feedback
Data
S1, S2
w21S1+w22S2
BS
BS
MS
MS
Network backhaul
w11S1 w2S1
h11h12
h21
h22
Single-cell operation
Enhanced service provisioning, especially for cell-edge users
OFDMA and 4G
CoMP (COordinated MultiPoint Transmission/Reception)
Coordinated multipoint Tx/Rx(COMP)
Goal of COMP
SINR improvement : larger signal energy and less interference
Better cell edge performance and larger cell throughput
High Performance Potential
– Straightforward in uplink
– Feedback of channel status information challenging
Required operations
Increased uplink feedback from UEs
Synchronization between the transmission point (cells)
Practical challenges remain
Downlink reference signal design and multi-cell channel estimation support
Uplink terminal feedback and required reporting schemes
Definition, configuration and coordination of the cell sets
MS
BS
BS
BS
BS
BS
BSBS
BS
Central Unit
OFDMA and 4G
Relay for Coverage Extension
Definition of Relay
– A new way of communication for user terminals or dedicated relay nodes to share their antennas providing the multiple signal routes(virtual multiple-antenna system)
Direct communication
Simple Relaying
Multi-hop Relaying
S
S
S
S
R
R R
D
D
D D D
DSource Relay Destination
Virtual MIMOCooperative Relaying
S
S
S
S
S
R
R
R
R
R
D
D
D
D
S R D
OFDMA and 4G
Relay for Coverage Extension
L0 relay(=Repeater)
– Amplify and forward(analog
amplifier),not seen by terminal
L1 relay
– Digital buffering and forward
– Added delay compared to L0 relay
L2 relay (Type II)
– Decode and forward
– Possibly scheduling functionality
L3 relay (Type I)
– Same as base station from terminal
perspective
– Wireless backhauling
Reason for Relay
– Coverage Extension
– Throughput/capacity gain
Benefits of Relay vs. Pico net
– Lower cost : no fiber backhaul
– Flexibility Main focus is on L3 relay
and stationary, single-hop relay
BS RS
MS
MS
MS
MS
MS
BS coverage
area
RS coverage
area
OFDMA and 4G
Bandwidth Extension
Motivations
– LTE-A peak rate of 1Gbps in DL(support≥40MHz)
– Operations need a technology to make best use of spectrum
How?
– Carrier Aggregation : Aggregation of multiple LTE carriers
Issues
– Aggregation of contiguous spectrum vs. non-contiguous spectrum
– Backward compatibility : LTE terminal able to access LTE-Advanced network
20 MHz 20 MHz 20 MHz
<60 MHz bandwidth by carrier aggregation>
OFDMA and 4G
Multiple Antenna Features
Extended multi-antenna transmission
– Spatial multiplexing in uplink
Up to 4x4 MIMO
– Increased spatial multiplexing in downlink
Up to 8x8 MIMO
– Enhanced downlink multi-user MIMO
– Non codebook based beamformed spatial multiplexing in downlink
Classical beamforming via dedicated reference signals
BSMS
BSMS
BSMS
Higher data rates and improved system efficiency
OFDMA and 4G
UL SC-FDMA Enhancement
Enhancement on SC-FDMA Uplink Waveform
– LTE-A UE adopts “N x DFTS-OFDM” across component carriers
Single-carrier transmission is not met in case of N x DFTS-OFDM
Possible to re-use the LTE transmitter/receiver implementations
Enables HARQ and MCS to be component-carrier specific
Same implementation for both contiguous and non-contiguous carriers
20MHz 20MHz 20MHz
IDFT IDFT IDFT
DF
T
DF
T
DF
T
OFDMA and 4G
Building on Releases
Release 10 LTE-Advanced
meeting the requirements set by
ITU’s IMT-Advanced project.
Also includes quad-carrier
operation for HSPA+.
Release 99: Enhancements to
GSM data (EDGE). Majority of
deployments today are based on
Release 99. Provides support for
GSM/EDGE/GPRS/WCDMA
radio-access networks.
Release 4: Multimedia
messaging support. First steps
toward using IP transport in the
core network.
Release 5: HSDPA. First phase
of Internet Protocol Multimedia
Subsystem (IMS). Full ability to
use IP-based transport instead of
just Asynchronous Transfer
Mode (ATM) in the core
network.
Release 6: HSUPA. Enhanced
multimedia support through
Multimedia Broadcast/Multicast
Services (MBMS). Performance
specifications for advanced
receivers. Wireless Local Area
Network (WLAN) integration
option. IMS enhancements. Initial
VoIP capability.
Release 7: Evolved EDGE. Specifies HSPA+, higher order modulation and MIMO. Performance enhancements, improved
spectral efficiency, increased capacity, and better resistance to interference. Continuous Packet Connectivity (CPC) enables
efficient “always-on” service and enhanced uplink UL VoIP capacity, as well as reductions in call set-up delay for Push-to-Talk
Over Cellular (PoC). Radio enhancements to HSPA include 64 Quadrature Amplitude Modulation (QAM) in the downlink DL
and 16 QAM in the uplink. Also includes optimization of MBMS capabilities through the multicast/broadcast, single-frequency
network (MBSFN) function.
Release 8: HSPA Evolution,
simultaneous use of MIMO and
64 QAM. Includes dual-carrier
HSPA (DC-HSPA) wherein two
WCDMA radio channels can be
combined for a doubling of
throughput performance.
Specifies OFDMA-based 3GPP
LTE.
Defines EPC.
Release 9: HSPA and LTE
enhancements including HSPA
dual-carrier operation in
combination with MIMO, EPC
enhancements, femtocell
support, support for regulatory
features such as emergency
user-equipment positioning and
Commercial Mobile Alert
System (CMAS), and evolution
of IMS architecture.
Text adapted from 3G Americas White Paper, September 2010
OFDMA and 4G
OFDMA and 4G
Peak data rate
Goal: significantly increased peak data rates, scaled linearly according to spectrum allocation
Targets:
– Instantaneous downlink peak data rate of 100Mbit/s in a 20MHz downlink spectrum (i.e. 5 bit/s/Hz)
– Instantaneous uplink peak data rate of 50Mbit/s in a 20MHz uplink spectrum (i.e. 2.5 bit/s/Hz)
The Enhanced UTRAN (E-UTRAN) will:
– be optimised for mobile speeds 0 to 15 km/h
– support, with high performance, speeds between 15 and 120 km/h
– maintain mobility at speeds between 120 and 350 km/h
and even up to 500 km/h depending on frequency band
– support voice and real-time services over entire speed range
with quality at least as good as UTRAN
OFDMA and 4G
Radio interface: Overall architecture
eNB
MME/SAE Gateway MME/SAE Gateway
eNB
eNB
S1
S1
S1
S1
X2
X2X
2
E-UTRAN
eNodeB
Functions for Radio Resource Management:
–Radio Bearer Control,
–Radio Admission Control,
–Connection Mobility Control,
–Dynamic allocation of resources to UEs in both
uplink and downlink (scheduling);
IP header compression and encryption of user data
stream;
Selection of an MME at UE attachment;
Two interfaces:
–S1 for the Control plane
–X1 for the User plane (new)
Additional interface in between eNode Bs: X2
–Including both Control and User plane
OFDMA and 4G
LTE TDD & FDD share common N/w Ecosystem
S1-U
S1-MME
S11
S6a
SGi
S5
HSS
MME
S-GW
Gx Gxc eN
B
Applications Step 2
2. MMTel
3. IPTV VoD
PDN-GW
PCRF
Rx
OSS
IMS Core
Internet
Applications Step 1
Web, FTP, Video Streaming
FTP Server
Video Server
Web Server
MMTel Application
Server
IPTV Application
Server
SGi
Common to FDD
and TDD
Parts of L1
L2, L3
Different between
FDD and TDD
High Degree of commonality between TDD and FDD on network side *Minimum changes in HW and SW
Enabling Technologies for LTE-Advanced
Peak Data Rate improvement
– DL 4x4 : LTE baseline 2x2
– UL 2x4 : LTE baseline 1x2
– 8 Tx antennas at eNode-B including 8x8 MIMO spatial multiplexing is also considered
Sector/cell throughput improvement
– Advanced Downlink MU-MIMO: 8 Tx beam-forming
– Uplink SU-MIMO
– Hybrid OFDMA and SC-FDMA in uplink
– Multi-stream MIMO SFN broadcast
– Superposition of unicast and broadcast traffic
Cell edge performance improvement
– Multi-hop relay – coverage extension
– Multi-cell MIMO (Network MIMO) – toward a cell without cell edge?
OFDMA and 4G
Advanced MU-MIMO: 8Tx Beam-forming
0 2 4 6 8 10 120.05
0.1
0.15
0.2
0.25
0.3
0.35
0.4
0.45
0.5
5%
User
Thro
ughput
(bps/H
z)
# of UEs
Baseline-1x2
MUBF2x2
MUBF4x2
MUBF8x2
0 2 4 6 8 10 121
2
3
4
5
6
7
8
9
Syste
m T
hro
ughput
(bps/H
z)
# of UEs
Baseline-1x2
MUBF2x2
MUBF4x2
MUBF8x2
5%-tile UE throughput Sector throughput
• 8Tx beam-forming provides
– Higher beam resolution, increased
coverage, larger beam forming gain and
larger number of simultaneous beams in
one sector
– Both throughput and coverage gain
• Cell edge performance gain of up to150% against 4x2 case
with 12 UEs/cell
• Issue: pilot provisioning
Multi-cell Network MIMO
Network backhaul
Less co-channel interference, more signal
Better cell edge performance
Requirements:
– Increased uplink feedback overhead
– Synchronization to more than one cell
11h 12h
21h
22h
11 1 12 2w S w S 21 1 22 2w S w S
Precoding
Data
S1,S2
Channel Info
feedback
Zero forcing example:
1
11 12 11 12
21 22 21 22
w w h h
w w h h
OFDMA and 4G
MBSFN Spatial Multiplexing
MBSFN system is bandwidth limited particularly in smaller cells
MBSFN signals received from multiple antennas from multiple cells are decorrelated – Potential for performance improvement using MIMO spatial multiplexing
Base layer is carried with more robustness (better coding, modulation and/or higher power).
UEs with good channel conditions can also decode the enhanced layer by canceling the base layer signal
– Allows differentiated QoS
Broadcast/
Multicast
Controller
Broadcast/
Multicast
Content
Server
eNB
N
eNB1
eNB2
Same Broadcast
Multicast
Information
DMUXANT1
ANT2
S1
S2
Base
Enhanced
DMUXANT1
ANT2
S1
S2
Base
Enhanced
DMUXANT1
ANT2
S1
S2
Base
Enhanced
OFDMA and 4G
MBSFN/Unicast Superposition
Free MBMS Capacity
Unused Node-B Power
Unicast
SFN MBMS
Unicast Unicast
Cancelled MBMS signal
Total Node-B Power
• Unicast traffic is (often)
interference limited; broadcast is
not.
• Borrow some unicast power
without affecting unicast
performance and use this power for
MBSFN superposition
• Greater than 2b/s/Hz MBSFN
(20Mb/s in 10MHZ bandwidth)
throughput without degrading
unicast performance
– System simulations
according to case-1 in
LTE TR 25.814.
+ =
- =
Transmitter
Receiver
Composite MBSFN Unicast
Unicast MBSFN Composite
OFDMA and 4G
Dense Urban Urban Sub-Urban Sub-Urban Urban
Traffic Density Variations across City Relative density
R SU
Traffic Distribution
OFDMA and 4G
IMT-Advanced Technologies
Key Feature of IMT Advanced Standards (1)
Technology Description IEEE 802.16m 3GPP LTE-Adv
Multi-cell
Cooperative
Transmission
-Cell edge throughput improvement
-High data rate coverage extension
Support
(Multi-cell MIMO) Support(CoMP)
Relay
-Coverage hole elimination
-High data rate coverage extension
-Replacement of wire backhaul
Support Support
Wider Bandwidth -Utilization of contiguous/noncontiguous
spectrum segments
Support
(Multi-carrier)
Support
(Carrier Aggregation)
Enhanced MIMO
-Increase of Peak data rate and cell
throughput
-DL : 8x8 MIMO
-UL : 4x4 MIMO
Support Support
OFDMA and 4G
IMT-Advanced Technologies
Key Feature of IMT Advanced Standards (2)
Technology Description IEEE
802.16m
3GPP
LTE-Adv
UL SC-FDMA
Enhancement
-Allocation of non-contiguous frequency blocks :
Increase cell throughput
-Transmission on separate carriers for control and data
channels
Not applicable
(UL : OFDMA) Support
Femto
-Low Tx power BS typically for home/SOHO
applications
-Extend coverage(connected via DSL or Cable network)
-Enhance service quality for user perspective
Support Support
SON -Limit the human intervention to install BSs Support Support
Multi-Radio
Coexistence in
One Device
-For interference management with other radio
technologies such as Wifi, Bluetooth, etc. Support Not Support
OFDMA and 4G
IMT-Advanced Technologies
Minimum requirements of IMT Advanced
– Cell spectral efficiency
– Peak Spectral Efficiency
– Bandwidth
– Normalized Cell edge user throughput
– Latency
– VoIP Capacity
– Mobility
– Handover
OFDMA and 4G
IMT-Advanced Technologies
Cell spectral efficiency
Peak Spectral Efficiency
– Downlink peak spectral efficiency is 15 b/s/Hz
– Uplink peak spectral efficiency is 6.75 b/s/Hz
– assumptions on antenna configuration (Downlink – 4x4, Uplink – 2x4)
Bandwidth
– The RIT shall support a scalable bandwidth up to and including 40 MHz
Test environment Downlink (b/s/Hz/cell)
Antenna config. - 4x2
Uplink (b/s/Hz/cell)
Antenna config. - 2x4
Indoor 3 2.25
Microcellular 2.6 1.8
Base coverage urban 2.2 1.4
High speed 1.1 0.7
OFDMA and 4G
IMT-Advanced Technologies
Normalized Cell edge user throughput
Latency – Control plane latency : 100 ms, User plane latency : 10 ms
VoIP Capacity
Test environment Downlink (b/s/Hz) Uplink (b/s/Hz)
Indoor 0.1 0.07
Microcellular 0.075 0.05
Base coverage urban 0.06 0.03
High speed 0.04 0.015
Test environment Min VoIP capacity (Active users/sector/MHz)
Indoor 50
Microcellular 40
Base coverage urban 40
High speed 30
OFDMA and 4G
IMT-Advanced Technologies
Mobility
Handover
Item Requirement value
Environment Indoor Micro cell Macro cell High speed
Frequency efficiency
(bps/Hz)
1.0
(3km/h)
0.75
(30km/h)
0.55
(120km/h)
0.25
(350km/h)
Handover Type Interruption Time (ms)
Intra-Frequency 27.5
Inter-Frequency
– within a spectrum band
– between spectrum bands
40
60
OFDMA and 4G
Questions?
Questions? OFDMA and 4G
OFDMA and 4G 49
Thank You