22
TM Freescale Semiconductor Proprietary Information. Freescale™ and the Freescale logo are trademarks of Freescale Semiconductor, Inc. All other product or service names are the property of their respective owners. © Freescale Semiconductor, Inc. 2008. LTE: MIMO Techniques in 3GPP-LTE Nov 5, 2008 Dr. Jayesh Kotecha Jason Wong R&D, Cellular Products Group GSM PM101

AM105 LTE: MIMO Techniques in 3GPP-LTE - 3g4g.co.uk · LTE: MIMO Techniques in 3GPP-LTE Nov 5, 2008 Dr. Jayesh Kotecha Jason Wong R&D, Cellular Products Group GSM PM101. …

  • Upload
    doquynh

  • View
    242

  • Download
    3

Embed Size (px)

Citation preview

Page 1: AM105 LTE: MIMO Techniques in 3GPP-LTE - 3g4g.co.uk · LTE: MIMO Techniques in 3GPP-LTE Nov 5, 2008 Dr. Jayesh Kotecha Jason Wong R&D, Cellular Products Group GSM PM101. …

TM

Freescale Semiconductor Proprietary Information. Freescale™ and the Freescale logo are trademarksof Freescale Semiconductor, Inc. All other product or service names are the property of their respective owners. © Freescale Semiconductor, Inc. 2008.

LTE: MIMO Techniques in 3GPP-LTE

Nov 5, 2008

Dr. Jayesh Kotecha Jason WongR&D, Cellular Products Group GSM

PM101

Page 2: AM105 LTE: MIMO Techniques in 3GPP-LTE - 3g4g.co.uk · LTE: MIMO Techniques in 3GPP-LTE Nov 5, 2008 Dr. Jayesh Kotecha Jason Wong R&D, Cellular Products Group GSM PM101. …

TMFreescale Semiconductor Proprietary Information. Freescale™ and the Freescale logo are trademarksof Freescale Semiconductor, Inc. All other product or service names are the property of their respective owners. © Freescale Semiconductor, Inc. 2008. 2

Goals of LTE

► Higher system throughput► Increasing coverage ► Higher peak data rates► MIMO critical to achieving targets!

BS

Handset

PDA

User Terminal

Page 3: AM105 LTE: MIMO Techniques in 3GPP-LTE - 3g4g.co.uk · LTE: MIMO Techniques in 3GPP-LTE Nov 5, 2008 Dr. Jayesh Kotecha Jason Wong R&D, Cellular Products Group GSM PM101. …

TMFreescale Semiconductor Proprietary Information. Freescale™ and the Freescale logo are trademarksof Freescale Semiconductor, Inc. All other product or service names are the property of their respective owners. © Freescale Semiconductor, Inc. 2008. 3

LTE Target Review

►OFDMA in Downlink (Unicast and Broadcast)►SC-FDMA in Uplink

►System performance targets and comparisons of LTE (2x2 and 1x2 baseline in DL and UL) with HSDPA (1x2 and 1x2 in DL and UL)

• User spectral efficiency: 3 to 4x in DL & 2 to 3x in UL• Average spectral efficiency: 3 to 4x in DL & 2 to 3x in UL• Cell Edge SE (5% cdf): 2 to 3x in DL & 2 to 3x in UL• Mobility: 0-15km(optimized), 15-120km(high), 120-350[500]km

(workable)• Coverage: 5km, 30km(slight degradation), 100km (not precluded)• E-MBMS (broadcast mode): better than HSPA MBMS • Feedback overhead (DL is 20-30%) – minimize• Minimize the number of modes• Minimize complexity

Page 4: AM105 LTE: MIMO Techniques in 3GPP-LTE - 3g4g.co.uk · LTE: MIMO Techniques in 3GPP-LTE Nov 5, 2008 Dr. Jayesh Kotecha Jason Wong R&D, Cellular Products Group GSM PM101. …

TMFreescale Semiconductor Proprietary Information. Freescale™ and the Freescale logo are trademarksof Freescale Semiconductor, Inc. All other product or service names are the property of their respective owners. © Freescale Semiconductor, Inc. 2008. 4

►14 OFDM symbol sub-frame►Control bits in a max of first

three OFDM symbols►Reference symbols and

control bits used for channel estimation, CQI measurement and cell search & initial acquisition.

►Localized and distributed RBs

DL Sub-frame Structure

R1

: First reference symbol

D D D D D D D D D D D D D D D D D D D

D D D D D D D D D D D D D D D D D D D

D D D D D D D D D D D D D D D D D D D

D D D D R2 D D D D D R2 D D D D D R2 D D

D D D D D D D D D D D D D D D D D D

D D D D D D D D D D D D D D D D D D D

0.5 ms

Frequency Domain

R2

: Second reference symbol D : Data

D R1 D D D D D R1 D D D D D R1 D D D D D

D

Physical resource block bandwidth and number of physical

resource blocks dependent on bandwidth.

Bandwidth (MHz) 1.4 3.0 5.0 10.0 15.0 20.0

Physical resource block bandwidth (kHz) 180 180 180 180 180 180

Number of available physical resource blocks

6 15 25 50 75 100

Page 5: AM105 LTE: MIMO Techniques in 3GPP-LTE - 3g4g.co.uk · LTE: MIMO Techniques in 3GPP-LTE Nov 5, 2008 Dr. Jayesh Kotecha Jason Wong R&D, Cellular Products Group GSM PM101. …

TMFreescale Semiconductor Proprietary Information. Freescale™ and the Freescale logo are trademarksof Freescale Semiconductor, Inc. All other product or service names are the property of their respective owners. © Freescale Semiconductor, Inc. 2008. 5

LTE Technologies Overview

►Multiple access in the frequency domain – localized and distributed resource blocks – scheduling gains

►Link adaptation – adaptive modulation and coding

►Hybrid ARQ

►MIMO

►Interference management

►Power control

Sometimes competing technologies for the same gain pool – study of interaction of these is critical to optimize the system

Page 6: AM105 LTE: MIMO Techniques in 3GPP-LTE - 3g4g.co.uk · LTE: MIMO Techniques in 3GPP-LTE Nov 5, 2008 Dr. Jayesh Kotecha Jason Wong R&D, Cellular Products Group GSM PM101. …

TMFreescale Semiconductor Proprietary Information. Freescale™ and the Freescale logo are trademarksof Freescale Semiconductor, Inc. All other product or service names are the property of their respective owners. © Freescale Semiconductor, Inc. 2008. 6

Interplay of Technologies – Examples

►Multi-antenna diversity vs. scheduling

►Frequency selectivity (LRB or DRB) vs. scheduling

►Interplay of different diversity (time-freq-space) gains due to HARQ, scheduling, channel coding, transmit diversity and space-time coding

Page 7: AM105 LTE: MIMO Techniques in 3GPP-LTE - 3g4g.co.uk · LTE: MIMO Techniques in 3GPP-LTE Nov 5, 2008 Dr. Jayesh Kotecha Jason Wong R&D, Cellular Products Group GSM PM101. …

TMFreescale Semiconductor Proprietary Information. Freescale™ and the Freescale logo are trademarksof Freescale Semiconductor, Inc. All other product or service names are the property of their respective owners. © Freescale Semiconductor, Inc. 2008. 7

Multiple Antenna Schemes in LTE

►Open loop – for control and data channels (higher Doppler)• Spatial multiplexing• Space-time codes / transmit diversity • Cyclic delay diversity

►Closed loop – for data channels, low Doppler• Linear pre-coding• Rank adaptation

►Multi-user MIMO – SDMA – closely spaced antennas

►Virtual MIMO - uplink

►MIMO in E-MBMS

Page 8: AM105 LTE: MIMO Techniques in 3GPP-LTE - 3g4g.co.uk · LTE: MIMO Techniques in 3GPP-LTE Nov 5, 2008 Dr. Jayesh Kotecha Jason Wong R&D, Cellular Products Group GSM PM101. …

TMFreescale Semiconductor Proprietary Information. Freescale™ and the Freescale logo are trademarksof Freescale Semiconductor, Inc. All other product or service names are the property of their respective owners. © Freescale Semiconductor, Inc. 2008. 8

LTE MIMO PHY DL Architecture

Deinterleaver/Channel decoder

Soft bitGenerator

Informationbits

Channel coding/interleaving

QAMModulation IFFT

Soft bitGenerator

Deinterleaver/Channel decoder

FFT

FFT

FFT

FFT

Informationbits

Channel coding/interleaving

QAMModulation IFFT

MIMO Receiver

CodewordTo LayerMapping

IFFT

IFFT

► Multiple transmit antennas at BS/eNodeB – 1,2 or 4► Multiple receive antennas at user end – 2

eNodeB User End

Feedback

Page 9: AM105 LTE: MIMO Techniques in 3GPP-LTE - 3g4g.co.uk · LTE: MIMO Techniques in 3GPP-LTE Nov 5, 2008 Dr. Jayesh Kotecha Jason Wong R&D, Cellular Products Group GSM PM101. …

TMFreescale Semiconductor Proprietary Information. Freescale™ and the Freescale logo are trademarksof Freescale Semiconductor, Inc. All other product or service names are the property of their respective owners. © Freescale Semiconductor, Inc. 2008. 9

Pre-coding

Informationbits

Channel coding/Interleaving/

HARQ

SpatialMulti-

plexing

FFT

FFT

MIMO Receiver

Soft bitGenerator

Deint/Channeldecoder

FFT

FFT

QAMModulatio

n

QAMModulatio

n

Pre-coding

2 x 2 Pre-coded MIMO Simplified System Block Diagram

Page 10: AM105 LTE: MIMO Techniques in 3GPP-LTE - 3g4g.co.uk · LTE: MIMO Techniques in 3GPP-LTE Nov 5, 2008 Dr. Jayesh Kotecha Jason Wong R&D, Cellular Products Group GSM PM101. …

TMFreescale Semiconductor Proprietary Information. Freescale™ and the Freescale logo are trademarksof Freescale Semiconductor, Inc. All other product or service names are the property of their respective owners. © Freescale Semiconductor, Inc. 2008. 10

Rank Adaptation

► Adapt number of streams to SNR and spatial scattering

►Higher SNR – more streams possible

► Cell edge – single stream pre-coding (transmit beamforming gain)

BS

Handset

PDA

User Terminal

Page 11: AM105 LTE: MIMO Techniques in 3GPP-LTE - 3g4g.co.uk · LTE: MIMO Techniques in 3GPP-LTE Nov 5, 2008 Dr. Jayesh Kotecha Jason Wong R&D, Cellular Products Group GSM PM101. …

TMFreescale Semiconductor Proprietary Information. Freescale™ and the Freescale logo are trademarksof Freescale Semiconductor, Inc. All other product or service names are the property of their respective owners. © Freescale Semiconductor, Inc. 2008. 11

CQI Feedback

► UE feeds back • Channel quality information (CQI) => preferred modulation and coding

rate• Preferred Rank • Preferred precoding matrix index (PMI)• Groups of resource blocks = subbands => CQI/PMI feedback is on a per

subband basis (not per RB basis) due to overhead constraints.Example - 20 MHz has 100 RBs – overhead is prohibitive on per RB basis

►CQI/PMI feedback types – configurable by Node B• Wideband – One CQI/PMI value for entire band• Best-M – One CQI/PMI value for best M subbands• Per Subband – One CQI/PMI value for each subband• Rank – One value for any CQI/PMI feedback type

Page 12: AM105 LTE: MIMO Techniques in 3GPP-LTE - 3g4g.co.uk · LTE: MIMO Techniques in 3GPP-LTE Nov 5, 2008 Dr. Jayesh Kotecha Jason Wong R&D, Cellular Products Group GSM PM101. …

TMFreescale Semiconductor Proprietary Information. Freescale™ and the Freescale logo are trademarksof Freescale Semiconductor, Inc. All other product or service names are the property of their respective owners. © Freescale Semiconductor, Inc. 2008. 12

Transmit diversity

Informationbits

Channel coding/interleaving

QAMModulation

Soft bitGenerator

Deinterleaver/Channel decoder

FFT

FFT

FFT

FFT

STDecoder

STEncoder

IFFT

IFFT

IFFT

IFFT

4 x 2 MIMO Simplified System Block Diagram

Page 13: AM105 LTE: MIMO Techniques in 3GPP-LTE - 3g4g.co.uk · LTE: MIMO Techniques in 3GPP-LTE Nov 5, 2008 Dr. Jayesh Kotecha Jason Wong R&D, Cellular Products Group GSM PM101. …

TMFreescale Semiconductor Proprietary Information. Freescale™ and the Freescale logo are trademarksof Freescale Semiconductor, Inc. All other product or service names are the property of their respective owners. © Freescale Semiconductor, Inc. 2008. 13

Multi-user MIMO - SDMA

H1

H2

Hm

.

.

.

.

.

.

.

.

.

w1

w2

wm

s1

s2

sm

.

.

.

.

.

.

.

.

.

1

2

N

v1

v2

vm

.

.

.

z1

z2

zm

UEm

y1

y2

ym

.

.

.

.

.

.

.

.

.

1

k►Multiple users

share same time-frequency resources

►Users separated in spatial domain

BS

UE1

UE2BS

Handset

Same time frequency resources

Page 14: AM105 LTE: MIMO Techniques in 3GPP-LTE - 3g4g.co.uk · LTE: MIMO Techniques in 3GPP-LTE Nov 5, 2008 Dr. Jayesh Kotecha Jason Wong R&D, Cellular Products Group GSM PM101. …

TMFreescale Semiconductor Proprietary Information. Freescale™ and the Freescale logo are trademarksof Freescale Semiconductor, Inc. All other product or service names are the property of their respective owners. © Freescale Semiconductor, Inc. 2008. 14

Downlink Beamforming

►Transmit beamformingweights to antennas

►Increases coverage – higher received SNR during focused beam transmission

►User end unaware of number of transmit antennas used for DL beamforming – appears as single antenna transmission

►Targeted for rural deployments – larger cells

HandsetBS

Handset

Page 15: AM105 LTE: MIMO Techniques in 3GPP-LTE - 3g4g.co.uk · LTE: MIMO Techniques in 3GPP-LTE Nov 5, 2008 Dr. Jayesh Kotecha Jason Wong R&D, Cellular Products Group GSM PM101. …

TMFreescale Semiconductor Proprietary Information. Freescale™ and the Freescale logo are trademarksof Freescale Semiconductor, Inc. All other product or service names are the property of their respective owners. © Freescale Semiconductor, Inc. 2008. 15

Multi-antenna Channels in LTE

►PDCCH – Transmit diversity

►PBCH - Transmit diversity (Blind Antenna detection)

►PDSCH – Closed loop pre-coding, open loop spatial multiplexing, transmit diversity

Page 16: AM105 LTE: MIMO Techniques in 3GPP-LTE - 3g4g.co.uk · LTE: MIMO Techniques in 3GPP-LTE Nov 5, 2008 Dr. Jayesh Kotecha Jason Wong R&D, Cellular Products Group GSM PM101. …

TMFreescale Semiconductor Proprietary Information. Freescale™ and the Freescale logo are trademarksof Freescale Semiconductor, Inc. All other product or service names are the property of their respective owners. © Freescale Semiconductor, Inc. 2008. 16

Receiver Design

► MMSE Receiver• Low complexity• Good performance• Interference rejection capabilities

► Maximum Likelihood Detectors• Highest complexity• Optimal performance

► Near ML Detectors• QR-MLD• Higher complexity• Performance closest to MLD

► Successive Interference Cancellation Receivers• High complexity • Performance between MMSE and ML detectors

Page 17: AM105 LTE: MIMO Techniques in 3GPP-LTE - 3g4g.co.uk · LTE: MIMO Techniques in 3GPP-LTE Nov 5, 2008 Dr. Jayesh Kotecha Jason Wong R&D, Cellular Products Group GSM PM101. …

TMFreescale Semiconductor Proprietary Information. Freescale™ and the Freescale logo are trademarksof Freescale Semiconductor, Inc. All other product or service names are the property of their respective owners. © Freescale Semiconductor, Inc. 2008. 17

Uplink Multi-Antenna Techniques

► No uplink single user MIMO• Lack of time to finish spec – but does not lack motivation

► Antenna selection• Selects “best antenna” for transmit • Needs only one RF chain• Needs extra duplexer – cost prohibitive

Page 18: AM105 LTE: MIMO Techniques in 3GPP-LTE - 3g4g.co.uk · LTE: MIMO Techniques in 3GPP-LTE Nov 5, 2008 Dr. Jayesh Kotecha Jason Wong R&D, Cellular Products Group GSM PM101. …

TMFreescale Semiconductor Proprietary Information. Freescale™ and the Freescale logo are trademarksof Freescale Semiconductor, Inc. All other product or service names are the property of their respective owners. © Freescale Semiconductor, Inc. 2008. 18

Virtual MIMO

►Virtual MIMO• Two users form a “virtual” multi-antenna transmission• BS separates the transmitted user streams

►Increased uplink spectral throughput

BS

Handset

Handset

Same time-frequencyresources

Page 19: AM105 LTE: MIMO Techniques in 3GPP-LTE - 3g4g.co.uk · LTE: MIMO Techniques in 3GPP-LTE Nov 5, 2008 Dr. Jayesh Kotecha Jason Wong R&D, Cellular Products Group GSM PM101. …

TMFreescale Semiconductor Proprietary Information. Freescale™ and the Freescale logo are trademarksof Freescale Semiconductor, Inc. All other product or service names are the property of their respective owners. © Freescale Semiconductor, Inc. 2008. 19

Proposed LTE-Advanced MIMO Enhancements

►Improvement of DL/UL peak & cell spectral efficiency ►Improvement of DL/UL cell edge user throughput by applying an

enhanced MIMO transmission considering multi-cell situation

eNodeB eNodeB

Relay Node Relay Node

UL SU-MIMO & TxD using multiple RF chains

UL Cooperative MIMOUL Cooperative MIMO

Multi-cell MIMO: Type 1 (DL/UL Cooperative MIMO)

MultiMulti--cell MIMO: Type 2cell MIMO: Type 2

(Adaptive Pre(Adaptive Pre--coding/coding/BeamformingBeamforming))

Wireless single-/multi-antenna transmission

Interference

Enhanced DL/UL MUEnhanced DL/UL MU--MIMOMIMO

Page 20: AM105 LTE: MIMO Techniques in 3GPP-LTE - 3g4g.co.uk · LTE: MIMO Techniques in 3GPP-LTE Nov 5, 2008 Dr. Jayesh Kotecha Jason Wong R&D, Cellular Products Group GSM PM101. …

TMFreescale Semiconductor Proprietary Information. Freescale™ and the Freescale logo are trademarksof Freescale Semiconductor, Inc. All other product or service names are the property of their respective owners. © Freescale Semiconductor, Inc. 2008. 20

LTE Advanced: MIMO Everywhere

►More complex antennas configurations8x8 MIMO DL; 4x8 UL MIMO - spectral efficiency gainsImprovement of UL peak & cell spectral efficiency

– Antenna power balancing– Low and uniform per-antenna PAPR

►Network MIMOMulti-cell/site MIMO transmission and reception

– Downlink/uplink cooperative MIMO – Pre-coding based dual-cell unicast transmission

Evolved DL/UL MIMO for inter-cell interference mitigation– Network Coordinated Interference Allocation and pre-coding– Enhanced DL/UL single-user MIMO– Enhanced DL/UL multi-user MIMO

Improvement of DL/UL cell edge user throughput as well as cell spectral efficiency

►Cost effective design for DL/UL control signaling

Page 21: AM105 LTE: MIMO Techniques in 3GPP-LTE - 3g4g.co.uk · LTE: MIMO Techniques in 3GPP-LTE Nov 5, 2008 Dr. Jayesh Kotecha Jason Wong R&D, Cellular Products Group GSM PM101. …

TMFreescale Semiconductor Proprietary Information. Freescale™ and the Freescale logo are trademarksof Freescale Semiconductor, Inc. All other product or service names are the property of their respective owners. © Freescale Semiconductor, Inc. 2008. 21

Related Session Resources

SessionsSession ID

DemosPedestal ID

PM104 LTE: Downlink Physical-Layer Overview and Throughput Simulation Results

Title

Demo Title

Session Location – Online Literature Libraryhttp://www.freescale.com/webapp/sps/site/homepage.jsp?nodeId=052577903644CB

Page 22: AM105 LTE: MIMO Techniques in 3GPP-LTE - 3g4g.co.uk · LTE: MIMO Techniques in 3GPP-LTE Nov 5, 2008 Dr. Jayesh Kotecha Jason Wong R&D, Cellular Products Group GSM PM101. …

TM