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1 NOKIA 2002 3GPP2 Wideband Codec Presentation

W-VRM: Wideband Variable-RateMulti-Mode Speech Codec for 3GPP2

Mitch Tseng, Ph.D.Nokia

January 21, 2002

3GPP2 TSG-S (Seoul, Korea) S00-20020121-006

Copyright 3GPP2 2002


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Topics

Wideband Speech Background

Codec Evolution

AMR-WB: Wideband Speech in 3GPP & ITU

W-VRM: Wideband Speech in 3GPP2 Audio Demonstration


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WIDEBAND SPEECH:

BACKGROUND MATERIAL


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WHAT IS WIDEBAND SPEECH?

The status quo narrowband speech codecs including PCMprovide a voice bandwidth of 300 Hz~3.4 kHz.

A wideband codec operates at a 16 kHz sampling rate and

provides a voice bandwidth of 50 Hz~7 kHz.

More bandwidth, both at the upper end and the lower end.

7 kHz3.4 kHz

Status Quo (PCM) Wideband

50 Hz 300 Hz


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WHY WIDEBAND SPEECH?

Current mobile systems and fixed line telephone networks offeronly narrowband speech services (~300-3400 Hz)

Recent advances in speech coding have made wideband codingfeasible in bit-rates applicable to mobile systems

Wideband provides superior quality over narrowband telephony

Increased naturalness (lowend)

Better fricativedifferentiation (high end)-> higher intelligibility

Increased presence-> feeling of transparentcommunication

Increased comfort

Easier speaker recognition

NarrowbandSpeech

300-3400Hz

Wideban

dSpeech

50-70

00Hz


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DEMONSTRATION: NARROWBANDVS WIDEBAND SPEECH

Experiencingthe Paradigm Shift

in End-to-End Voice Quality

300 Hz - 3.4 kHz

50 Hz - 7 kHzVoice Quality

NarrowbandMale

Speech

NarrowbandFemaleSpeech

WidebandFemaleSpeech

WidebandMale

Speech


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WHY WIDEBAND SPEECH NOW? Competitive Issues

A voice quality that is superior to the status quo and will sell in thefuture

All narrowband codecs today provide near-landline quality

(Squeezing the limit of PCM) Wideband codec voice quality far exceeds landline quality Challenge from Voice over IP

Worldwide Wideband Codec Efforts ITU G.722 for Multimedia Applications

3GPP Wideband AMR, multi-rate, each rate fixed with VAD/DTX

ITU-G.722.1: ITU Wideband Codec for Voice and Multimedia 3GPP AMR-WB = ITU-G.722.2

Our Objective To standardize a Multi-mode, Variable Rate Bandwidth-Efficient

Wideband Codec that fits in the CDMA2000 Rate Set 2

environment and can interoperate with other Wideband Codecs

ITU, 3GPP


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WIRELESS SPEECH CODEC

EVOLUTION WITH A LOOK AT THEFUTURE


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EVOLUTION OF WIRELESS SPEECHCODECS

IS-96A

Rate-Set I

1993 FR

13 kbps

1989

3GPP2:Variable RateSpeech Coding

3GPP:Fixed RateSpeech CodingWith VAD/DTX

QCELP13Rate-Set II

1994

EVRC

Rate-Set I

1995

SMVMultimodeRate-Set I

2001

HR

5.6 kbps

1995

EFR

12.2 kbps1996

AMR-NB

Multi-Rate

1999

3GPP/ITUAMR-WBMulti-Rate

2000-2001

W-VMRRate-Set II

Common Mode

Of Operation(Interoperable Mode)


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STATE-OF-THE-ART:VARIABLE RATE MULTI-MODE CODING

Increasing Average Data Rate

IncreasingVoiceQuality

Mode 2

Mode 1

SMV

Mode 0

EVRC

Quality/data rate curves

Narrowband Codecs

Mode 3


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VARIABLE RATE MULTI-MODEWIDEBAND SPEECH CODING

Increasing Average Data Rate

IncreasingVoiceQuality Mode 3

Mode 2

Wideband Codec

Mode 0

Quality/data rate curve

Mode 1

Rate Set 2Upper Limit

QCELP13


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3GPP2 CODECS: QUALITY AND CAPACITY

Increasing ADR

IncreasingVoice

Quality

QCELP13

SMVMode 0

EVRCSMV

Mode 3

SMVMode 2

SMVMode 1

Rate-Set IIRate-Set I

W-VRM

Mode 2W-VRMMode 3

W-VRMMode 1

W-VRMMode 0


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AMR-WB: WIDEBAND SPEECH

FOR 3GPP AND ITU


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THE AMR WIDEBAND CODECSTANDARD

3GPP approved the Adaptive Multi Rate WideBand(AMR-WB) codec standard in March 2001

In July 2001 AMR-WB was adopted as the new ITU-Twideband standard

First codec to be used both for wireless and wirelineservices: No transcoding between wireless and wirelinesystems

-> no loss of quality in the interconnection Simplifies the implementation of global wideband

speech services


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W-VRM: WIDEBAND VARIABLE-RATEMULTI-MODE SPEECH CODEC FOR

3GPP2


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W-VRM FOR 3GPP2: OVERVIEW

Proposed Codec is Ideal for 3GPP2 Applications: Less Complex than SMV (Lower Complexity and Lower Memory)

Same Algorithmic Delay as SMV with 20ms frame structure

Multi-mode, Variable Rate Codec functionally similar to SMV

Variable Rate to Provide Better Bandwidth Efficiency

Comparable Voice Quality with ITU/3GPP Wideband Codec

Provides Superb End-to-End Voice Quality at Rate Set2 and at QCELP13 Capacity

Suitable for 3GPP2 TFO and VoIP Applications

Interoperable with new ITU/3GPP Wideband Codec A Multi-mode Codec Functionally Similar to SMV


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W-VRM: PROPOSED REQUIREMENTS

Input sampling rate @ 16 kHz and audio bandwidth 50-7000 Hz

Frame size 20 ms

Multi-mode and variable-rate wideband coding system

Full compliance with IS-95/cdma2000 rate-set II in allmodes

No physical layer changes required.

Four modes of operation Mode 0: Worldwide Interoperable Mode Mode 1: Premium mode (Quality)

Mode 2: Standard mode (IS-733 ADR equivalence) Mode 3: Economy mode (Capacity)

Algorithmic delay less than 35 ms

Computational complexity less than SMV


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W-VRM Interoperable Mode

Mode 0(12.65kbps) Mode 0(12.65kbps)

[email protected]

[email protected]

OthersOthers

OtherModes

OtherModes

WB-VRMWB-VRM

WB-AMRWB-AMR

WCDMA

CDMA2000

Interoperable


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W-VRM Standardization


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W-VRM: APPLICATIONS

Tandem-Free Mobile-to-Mobile callsWideband speech codec can be used for transparent-networkmobile-to-mobile calls.

Wideband telephony over packet networks (Mobile-to-IP)The intrinsic bandlimited nature of the current PSTN and wireless

systems can be overcome through the use of IP networks. Teleconferencing

Wideband coding can further improve the quality of service forwireless/wireline teleconferencing systems beyond of what can be

achieved through the use of narrowband codecs.

Wireless MultimediaThere are a multitude of wireless multimedia applications such asstreaming and broadcasting that can benefit from the advantagesoffered by wideband speech coding.

Rate Set 2, Tandem Free and IP are the Keys


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W-VRM: STANDARDIZATION ASPECTSProposed Schedule

1Q 2002: Approval of the work item. Definition of thehigh-level requirements.

2Q 2002: Final definition of the requirements and

approval of the test plan for the wideband speech codec. 3Q 2002: Characterization and standardization of the

wideband codec and completion of the baselinespecifications.

Recommend TSG-S to approve the work item and Stage 1so that the Voice Services group (TSG-C WG1 SWG1) canstart the work ASAP.


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SUMMARY 3GPP and ITU Have Standardized a Common

Wideband Speech Codec wireless and wireline applications easily the best as the competition proved

3GPP2 Has the Opportunity to Harmonize Via

Our Own Wideband Speech Codec with aCommon Mode of Operation AMR-WB 12.65 mode = W-VRM Mode 0 other modes use variable-rate coding to furtherenhance system capacity

Work Item Initially Supported by Bell Mobility,Sprint PCS, SK Telecom, KT Freetel, ALLTELand Nokia.

wideband codec

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