RISS 검색 - 국내학술지논문 상세보기

다국어 초록 (Multilingual Abstract)

This paper proposes an algorithm to improve the compression performance of the adaptive multi-rate (AMR) speech coding using the context tree weighting (CTW) method. AMR is the voice encoding standard adopted by IMT-2000, and supports 8 transmission rates from 4.75 kbit/s to 12.2 kbit/s to cope with changes in the channel condition. CTW as a kind of the arithmetic coding, uses a variable-order Markov model. Considering that CTW operates bit by bit, we propose an algorithm that re-orders AMR data and compresses them with CTW. To verify the validity of the proposed algorithm, an experiment is conducted to compare the proposed algorithm with existing compression methods including ZIP in terms of compression ratio. Experimental results indicate that the average additional compression rate in AMR data is about 3.21% with ZIP and about 9.10% with the proposed algorithm. Thus our algorithm improves the compression performance of AMR data by about 5.89%.

국문 초록 (Abstract)

본 논문은 Context Tree Weighting (CTW) 를 이용하여 Adaptive Multi-Rate (AMR) 데이터의 압축 성능을 개선하는 알고리즘을 제안한다. AMR은 IMT-2000에서 채택된 음성부호화 표준안으로써, 무선채널의 환경...

본 논문은 Context Tree Weighting (CTW) 를 이용하여 Adaptive Multi-Rate (AMR) 데이터의 압축 성능을 개선하는 알고리즘을 제안한다. AMR은 IMT-2000에서 채택된 음성부호화 표준안으로써, 무선채널의 환경변화에 대처할 수 있도록 4.75 kbit/s 에서 12.2 kbit/s 까지 8가지의 전송률을 지원한다. CTW는 산술부호화기의 일종으로, 가변 차수 마르코프 모델을 사용하는 압축기이다. 우리는 CTW가비트단위로 수행한다는 점을 고려하여 AMR 데이터를 변환한 후 CTW로 압축하는 알고리즘을 제안한다. 제안하는 알고리즘의 유효성을 검증하기 위하여 ZIP을 포함한 기존 압축방식과 제안된 알고리즘의 압축률을 비교하는 실험을 하였다. 실험 결과, AMR 데이터의평균 추가 압축률이 ZIP의 경우 약 3.21%, 제안된 알고리즘의 경우 약 9.10%로 나타났다. 따라서 본 논문에서 제안한 알고리즘이 AMR 데이터의 압축 성능을 약 5.89% 개선하였다.

참고문헌 (Reference)

1 P. Buhlmann, "Variable length Markov chains" 27 (27): 480-513, 1999

2 F.M.J. Willems, "The context-tree weighting method: extensions" Institute of Electrical and Electronics Engineers (IEEE) 44 (44): 792-798, 1998

3 F.M.J. Willems, "The context-tree weighting method: basic properties" Institute of Electrical and Electronics Engineers (IEEE) 41 (41): 653-664, 1995

4 B. Bessette, "The adaptive multirate wideband speech codec (AMR-WB)" Institute of Electrical and Electronics Engineers (IEEE) 10 (10): 620-636, 2002

5 B. Bessette, "The adaptive multirate wideband speech codec (AMR-WB)" Institute of Electrical and Electronics Engineers (IEEE) 10 (10): 620-636, 2002

6 Alberto Apostolico, "Optimal Amnesic Probabilistic Automata or How to Learn and Classify Proteins in Linear Time and Space" Mary Ann Liebert Inc 7 (7): 381-393, 2000

7 "Mandatory Speech Codec speech precessing functions :AMR Speech Codec; Source Controlled Rate operation, 3GPP, 3G TS 26.093"

8 "ETSI Draft EN 301 708, Digital cellular telecommunication system(Phase 2+); Voice Activity Detector(VAD) for adaptive Multi-Rate(AMR) speech traffic channels"

9 "ETSI Draft EN 301 704, Digital cellular telecommunication system(Phase 2+); Adaptive Multi-Rate(AMR) speech transcoding"

10 "Digital cellular telecommunication system(Phase 2+);Substitution and mting of lost frames for Adaptive Multi-Rate(AMR) speech traffic channels, ETSI Draft EN 301 705"