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3GPP2 TSG-C LTE Activities

Byung K. YiTSG-C Chair

©2005 LG Electronics, Inc.LG Electronics, Inc. grants a free, irrevocable license to 3GPP2 and its Organizational Partners to incorporate text or other copyrightable material contained in the contribution and any modifications thereof in the creation of 3GPP2 publications; to copyright and sell in Organizational Partner's name any Organizational Partner's standards publication even though it may include all or portions of this contribution; and at the Organizational Partner's sole discretion to permit others to reproduce in whole or in part such contribution or the resulting Organizational Partner's standards publication. LG Electronics, Inc. is also willing to grant licenses under such contributor copyrights to third parties on reasonable, non-discriminatory terms and conditions for purpose of practicing an Organizational Partner’s standard which incorporates this contribution. This document has been prepared by LG Electronics, Inc. to assist the development of specifications by 3GPP2. It is proposed to the Committee as a basis for discussion and is not to be construed as a binding proposal on LG Electronics, Inc.. LG Electronics, Inc. specifically reserves the right to amend or modify the material contained herein and nothing herein shall be construed as conferring or offering licenses or rights with respect to any intellectual property of LG Electronics, Inc. other than provided in the copyright statement above.

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• Kickoff Date of Evolution Ad Hoc– 3GPP2 Beijing meeting, October 2005

• Contributions: Four (4) in total– Two (2) Visionary Presentations– Two (2) Technical Presentations

Introduction

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• Presented by TSG-C Chair

• New direction or reinventing the wheels by reflecting the telecommunications’ history

• Suggest measuring spectral efficiency in terms of “b/s/Hz/m2” instead of “b/s/Hz”

Chronicles of Important Events in Telecomm’s History

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• Presented by Lucent.• Phased approaches on cdma2000 evolution• Possible Approaches for Phase 2

– Backward compatible OFDMA for forward link (FL)– Coexistence of OFDMA and CDMA for reverse link

(RL)– TDD enhancements to FDD– Addition of secondary pilots to support SDMA/MIMO– Enhancements for VoIP

Future of cdma2000®

cdma2000® is the trademark for the technical nomenclature for certain specifications and standards of the Organizational Partners (OPs) of 3GPP2. Geographically (and as of the date of publication), cdma2000® is a registered trademark of the Telecommunications Industry Association (TIA-USA) in the United States.

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• Presented by LGE• Supports flexible operation by changing the

interleaver size• Gives the same performance with powerful

generalized repeat accumulator low density parity check code (GRA-LDPC)

• Supports low density parity check code with reduced complexity and memory requirements

Flexible LDPC

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J bits in to 1 bit out

• Encoder and Decoder Structures for F-LDPC. Code rate is J/(J+2)

Flexible LDPC (Cont’d)

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Flexible LDPC (Cont’d)

0.001

0.01

0.1

1

0 5 10 15 20 25 30

PE

R

SNR (dB)

Rate 1/2 BPSK – 32/33 256QAM

~0.25 dB

• Packet error rate (PER)

performance

of

F-LDPC in terms

of

modulation

and code rates

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• Presented by LGE• Proposed reduced complexity blind

multiuser detection scheme for forward link (FL) based on blind multiuser signal model

• Only spreading sequence(s) for user(s) of interest is required

• Gives a comparable performance with the decorrelating detector using all information on users

Blind Multiuser Detection (BMUD)

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Blind Multiuser Detection (BMUD) (Cont’d)

• Proposed

Blind

MUD

Structure

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Blind Multiuser Detection (BMUD) (Cont’d)

• Group size G=3, total users K=10, blind spreading matrix size M=40, spreading gain N=64

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• Presented by Nokia• Key Concepts

– Bandwidth support up to 20 MHz with 1.25 MHz as the basic frequency unit

– FDD mode of operation– Slot duration of 468.75 microsec as basic unit for

scheduling– Peak data rate of 210 Mbps @ 20 MHz with 4 transmit

x 4 receive antenna configuration– Flexible multiple access in frequency, and time and

spatial dimensions– Integrated approach to multi-user, multi-stream MIMO

Proposal for 3GPP2 Air Interface Evolution Phase 2

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– OFDM-based Air Interface

• FFT size varies with deployed BW• 4 OFDM symbols per slot

Proposal for 3GPP2 Air Interface Evolution Phase 2 (Cont’d)

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– Rate compatible punctured Turbo Codes are considered for FEC of the packet data transmission

– Other coding schemes are possible– Two multiplexing modes

• Frequency Block Multiplexing Mode (FBMM)– Basic unit BW for scheduling is 1.25 MHz– Contiguous tones for each user envisioned in this mode

• Frequency Diversity Multiplexing Mode (FDMM)– Interlace patterns are used as the mechanism for frequency

diversity multiplexing

Proposal for 3GPP2 Air Interface Evolution Phase 2 (Cont’d)

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– Closed loop MIMO for low mobility• Transmission over beams Beam-weights

estimated using feedback– Open loop MIMO for high mobility– Hybrid ARQ

• H-ARQ channels are synchronous• Time interval between different H-ARQ channels

can be different– Additional flexibility in accommodating delay and

throughput requirements

Proposal for 3GPP2 Air Interface Evolution Phase 2 (Cont’d)

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• Prepared by Lucent, Nortel and Samsung• Design Goals

– Flexibility• Anywhere: Macro, micro, pico cells and their

combinations• Anyhow: 1.25 MHz up to 20 MHz Fourier

bandwidth with TDD or FDD– Graceful evolution path from Rev. A– Spectral efficiency boost relative to Rev. A/B

• Via SDMA and MIMO

LNS Proposal for Air Interface Evolution Phase 2

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– Lower latencies relative to Rev. A/B• Higher VoIP capacity

– Complexity reduction at the PHY and MAC layer and allow refocus on support for richer application set

• Key Concepts– Two approaches of operation for FL and RL

• Loosely Backwards Compatible Mode– Legacy AT and new AT in separate carriers on both FL

and RL– FL: OFDMA– RL: Hybrid OFDMA and CDMA

LNS Proposal for Air Interface Evolution Phase 2 (Cont’d)

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• Strictly Backwards Compatible Mode– Co-existing Legacy AT & new AT on the same carrier– FL: OFDMA and CDMA multiplexed in frequency and

time slots– RL: CDMA on legacy carriers with Hybrid OFDMA-

CDMA on new carriers

– Multi-carrier transmission capability on FL and RL

– Support flexible and dynamic bandwidth scalability

LNS Proposal for Air Interface Evolution Phase 2 (Cont’d)

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– Key technologies to improve peak data rates, latencies and spectral efficiency

• OFDMA• MIMO• SDMA• Interference Cancellation

– New physical and MAC layer subtypes to support new features

LNS Proposal for Air Interface Evolution Phase 2 (Cont’d)