Browse > Article

Improved Harmonic-CELP Speech Coder with Dual Bit-Rates(2.4/4.0 kbps)  

김경민 (LG전자 기업통신연구소)
윤성완 (연세대학교 전기전자공학과 미디어통신신호처리 연구실)
최용수 (연세대학교 정보기술학부)
박영철 (연세대학교 전기전자공학과 미디어통신신호처리 연구실)
윤대희 (연세대학교 전기전자공학과 미디어통신신호처리 연구실)
강태익 (연세대학교 정보기술학부)
Publication Information
The Journal of Korean Institute of Communications and Information Sciences / v.28, no.3C, 2003 , pp. 239-247 More about this Journal
Abstract
This paper presents a dual-rate (2.4/4.0 kbps) Improved Harmonic-CELP(IHC) speech coder based on the EHC(Efficient Harmonic-CELP) which was presented by the authors. The proposed IHC employs the harmonic coding for voiced and the CELP for unvoiced segments. In the IHC, an initial voiced/unvoiced estimate is obtained by the pitch gain and energy. Then, the final V/UV mode is decided by using the frame energy contour. A new harmonic estimation combining peak picking and delta adjustment provides a more reliable harmonic estimation than that in the EHC. In addition, a noise mixing scheme in conjunction with an improved band voicing measurement provides the naturalness of the synthesized speech. To demonstrate the performance of the proposed IHC coder, the coder has been implemented and compared with the 2.0/4.0 kbps HVXC(Harmonic excitation Vector Coding) standardized by MPEG-4. Results of subjective evaluation showed that the proposed IHC coder and produce better speech quality than the HVXC, with only 40% complexity of the HVXC.
Keywords
Citations & Related Records
Times Cited By KSCI : 1  (Citation Analysis)
연도 인용수 순위
1 A 4kb/s Hybrid MELP/CELP Coder with Alignment Phase Encoding and Zero Phase Equalization /
[ T.Wang;K.Koishida;V.Cuperman;A.Gersho ] / Proc. of ICASSP 2000
2 /
[ W.B.Kleijin;K.K.Paliwal ] / Speech Coding and Synthesis
3 /
[] / Proposed TIA/EIA/PN-3292 Standard-Enhanced Variable Rate Codec, Speech Service Option 3 for Wideband Spread Spectrum Digital Systems, Official Ballot Version
4 The Spectral Envelope Estimaton Vocoder /
[ Douglas B.Paul ] / IEEE Trans. on Acoust. Speech and Signal Proc.
5 A Mixed Excitation LPC Vocoder Model for Low Bit Rate Speech Coding /
[ A.V.McCree;T.P.Barnwell Ⅲ ] / IEEE Trans on Acoust. Speech and Signal Proc.
6 Fast Vector-Sum Codebook Search Method for Low Bit Rate Speech Coding /
[ Y.S.Choi;S.W.Park;D.H.Youn ] / IEE Electronic Letters
7 효율적인 하모닉-CELP 구조를 갖는 저 전송률 음성부호화기 /
[ 최용수;김경민;윤대희 ] / 한국음향학회지   과학기술학회마을
8 Code-Excited Linear Prediction(CELP): High Quality Speech at Very Low Bit Rates /
[ M.R.Schroeder;B.S.Atal ] / IEEE Proc. ICASS
9 Fast Harmonic Estimation Using a Low Resolution Pitch for Low Bit Rate Harmonic Coding /
[ Y.S.Choi;D.H.Youn ] / Proc. of Euros speech 2001
10 Information Technology Very Low Bit Rate Audio-Visual Coding /
[] / ISO/IEC FCD 0.1 Subpart 2
11 Multi-Band Excitation Vocoder /
[ D.W.Griffin;J.S.Lim ] / IEEE Trans. on Acoust. Speech and Signal Proc.   ScienceOn
12 Efficient Harmonic-CELP Based Hybrid Coding of Speech at Low-Bit Rate /
[ Y.S.Choi;S.K.Ryu;Y.C.Park;D.H.Youn ] / Proc. of ICSLP 2000Ⅱ