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8/3/2019 TTA_Workshop_B4G_ETRI-2010
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IT R&D Global Leader
Mobile Research Activites of ETRI otential Technologies for Beyond
IMT-Advanced
September 10, 2010Young-Jo Ko
Next Generation Mobile CommunicationResearch Team
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Outline
Market demands and solutions
Potential technologies for Beyond IMT-AdvancedMulti-point transmission/reception
DAS, 3GPP CoMP
Heterogeneous networkPico, femto cells, interference coordination
Large-scale (or massive) MIMOMachine-type communicationsDevice to device communicationsOthers
Energy-savingPositioning
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Market demands and solutions
Recent developments in the marketExplosive growth of wireless traffic
Large screen mobile devices e.g. smartphones, laptopsMultimedia applications66x traffic growth between 2008 and 2013 (Cisco)
Increase of machine-type data traffic
Data traffic not involving humansNew applications and services
Location based servicesApplications based on peer-to-peer cooperation/communication
Environment-friendly green radios
Low-power consumptionReduction of greenhouse gas emission
Demand for low cost per bitReduced OPEX
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Market demands and solutions
Technological solutions to the demandsHigher spectral efficiency per area
Multi-point transmission/reception: DAS or CoMPHeterogeneous networksDevice-to-Device communicationsLarge-scale MIMO
Support for new applications and servicesAccurate positioningMachine-type communicationDevice-to-Device communication
Green radios
Network/UE power saving
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Multi-point transmission/reception
Distributed Antenna System (DAS)Joint transmission and reception across distributed antenna sitesTypes of DAS
Type 1: Antenna units are located in different geographic positions within the cell.Type 2: Antenna units are located over multiple cell sites.
Deployment scenarioseNB with remote radio heads (RRH)
Connection via Radio over Fiber (RoF)One large aggregated cell with antennas distributed over RRHs ->Type 1 DASMulti-cells with each RRH acting as a single cell -> Type 2 DAS
Cooperative eNBs with fast connection to each otherConnection via RoF or over-the-air (OTA) relayingIn addition to eNBs managing their own cell, inter-eNB cooperation is required for multi-cell transmission -> Type 2 DAS
Centralized antenna system DAS with RRHs
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Multi-point transmission/reception
Benefits of DAS
Joint transmission and reception across distributed antenna sitesImproves the coverage of high data rates, the cell-edge throughput and/or toincrease system throughput
Increased capability of distributed MIMOIndependent fading between different antenna units
Larger capacity expected than in the traditional collocated MIMO
DAS with cooperative multi-eNBs
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Multi-point transmission/reception
3GPP CoMP
Coordinated multiple point transmission and receptionLTE-Advanced Study Item (~ June 2011)CoMP categories:
Joint Processing (JP): data is available at each point in CoMP cooperating setJoint Transmission: PDSCH transmission from multiple points (part of orentire CoMP cooperating set) at a time
Dynamic cell selection: PDSCH transmission from one point at a time (withinCoMP cooperating set)Coordinated Scheduling/Beamforming (CS/CB): data is only available at servingcell (data transmission from that point) but user scheduling/beamforming decisionsare made with coordination among cells corresponding to the CoMP cooperatingset.
Cell A
UE
Cell B
HA
HB
Cell C
HC
Cell A
Cell A
UE
Cell B
HA
HBInterference
Signal
HC
Interference
Cell A
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Multi-point transmission
Further enhancement of 3GPP CoMP
Enhancement of downlink CoMPUplink CoMP
Multi-cell joint detection
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Heterogeneous networks
Heterogeneous deployment
Overlay of higher powered and low powered cellsLow power nodes are placed throughout a macro-cell layoutIncrease spectral efficiency per area
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Low power nodesPico, Femto, Remote Radio Head (RRH), Relay nodes
Hotzone cell (pico cell): typically planned deployments and open to all UEsHeNB (femto cell): consumer deployed and Closed Subscribed Group (CSG)
Interference problems in heterogeneous networksLarge interference due to restricted access
Femto (with CSG) – Macro interferenceFemto – Femto interference
Large interference due to range expansionPico – Macro interference
Heterogeneous networks
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Massive MIMO
Large-scale or massive MIMO
“Beyond LTE: Hundreds of Base Station Antennas! “, T. L. Marzetta etal (Bell Labs, Alcatel-Lucent)Extra base station antennas always help
+ eventually produce inter-cellular interference-limited operation+ eliminates effects of uncorrelated noise and fast fading+ compensate for poor-quality channel-state information
Multiuser MIMO, Perfect CSI at the transmitter
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Massive MIMO
Summary of limit analysisMulti-cellular TDD scenario, 42 terminals served per cell 500 μseccoherence interval (7 OFDM symbols): 3 reverse-link pilots, 1 idle, 3data
OFDM: 20 MHz bandwidth, cyclic prefix 4.76 μsecFading: Fast + log-normal shadow (8 dB) + geometric (3.8 power)
No inter-cell cooperation
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Massive MIMO
Cons
Requires to use TDDHow to put ~ 100 Tx antennas at the cell site?
Cost, space
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Machine-type Communication
Machine-Type Communication (MTC or M2M)
Data communication between devices or device(s) and server(s)that does not necessarily require human interactionM2M characteristics
a massive number of devicesdata communications
to a large extent, little traffic per device
infrequent communicationdiversified QoS requirement
low mobilitydevices that do not move, move only within a certain region
low power consumptiongroup based device management & communication
M2M applicationsSmart metering: power, gas, water, etcE-health: remote monitoring and diagnosticsConsumer electronicsTracking & tracing
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Machine-type Communication
3GPP MTC
System Improvements for MTCSystem architectural enhancements and the related optimizations for 3GPP Core NetworkKey aspects
Addressing and identifiersSignaling overhead and congestionGroup management
Radio Access Network Improvement for MTCImprovements for the efficient use of RAN resources while keeping the complexity due to M2M optimizations at a minimum levelKey aspects
RAN overload control: mass concurrent data and signaling transmission may cause intolerable delays, packet loss or even service unavailability. RAN level mechanisms to protect the overload, especially for RACH overload, are needed.
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Device-to-Device communications
Device-to-Device communications (D2D)
As an underlay to a cellular networkMulti-hop relaying to/from the eNBDirect peer-to-peer communications
ApplicationsLocal ad hoc networking
New types of short range servicesData intensive short range peer-to peercommunications
D2D communications share the sameresources with the cellular communication ->Increases the spectral efficiency
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Device-to-Device communications
Device-to-Device communications
Required functionsUE paring or clustering mechanism/procedureeNB – UE control procedure for D2DNew frame structure for D2D transmissionInterference management
Depending on resource allocation: dedicated or cellular resourcesPower control of D2D links
Link adaptationCSI estimationH-ARQ process
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