TTA_Workshop_B4G_ETRI-2010

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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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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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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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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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



Multi-point transmission

Further enhancement of 3GPP CoMP

Enhancement of downlink CoMPUplink CoMP

Multi-cell joint detection



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



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



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



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



Massive MIMO

Cons

Requires to use TDDHow to put ~ 100 Tx antennas at the cell site?

Cost, space



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



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.



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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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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Documents

TTA_Workshop_B4G_ETRI-2010