한국산학기술학회논문지 (Journal of the Korea Academia-Industrial cooperation Society)

  • 제12권9호
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  • Pages.4119-4124
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  • 2011
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  • 1975-4701(pISSN)
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  • 2288-4688(eISSN)
한국산학기술학회 (The Korea Academia-Industrial cooperation Society)
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멀티펄스의 진폭보정에 관한 연구

A Study on Compensation of Amplitude in Multi Pulse

  • 이시우 (상명대학교 정보통신공학과)
  • Lee, See-Woo (Dept. of Information and Telecommunication Engineering, Sangmyung University)
  • 투고 : 2011.05.31
  • 심사 : 2011.09.08
  • 발행 : 2011.09.30
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⟨ 이전 논문 다음 논문 ⟩

초록

유성음원과 무성음원을 사용하는 멀티펄스 음성부호화 방식에 있어서, 음성신호의 진폭이 증가하거나 감소하는 경우에 음성 파형에 일그러짐이 나타난다. 이것은 대표구간의 멀티펄스를 피치구간마다 복원하는 과정에서 재생 음성신호가 정규화되는 것이 원인으로 작용한다. 이것을 해결하기위하여 본 논문에서는 피치구간마다 멀티펄스의 진폭을 보정하는 방법(AC-MPC)을 제시하였으며, 기존의 MPC와 멀티펄스 진폭을 보정한 AC-MPC의 SNRseg를 평가한 결과, AC-MPC의 남자음성에서 0.7dB, 여자음성에서 0.7dB 개선된 것을 확인할 수 있었다. 결국, MPC에 비해 AC-MPC의 SNRseg가 개선되어 음성파형의 일그러짐을 제어할 수 있었으며, 본 방법은 셀룰러폰이나 스마트폰과 같이 Low Bit Rate의 음원을 사용하여 음성신호를 부호화하는 방식에 활용할 수 있을 것으로 기대된다.

In a MPC coding using excitation source of voiced and unvoiced, it would be a distortion of speech waveform in case of increasing or decreasing of speech signal amplitude in a frame. This is caused by normalization of synthesis speech signal in the process of restoration the multi-pulses of representation section. To solve this problem, this paper present a method of amplitude compensation(AC-MPC) in a multi-pulses each pitch interval in order to reduce distortion of speech waveform. I was confirmed that the method can be synthesized close to the original speech waveform. And I evaluate the MPC and AC-MPC using amplitude compensation method. As a result, SNRseg of AC-MPC was improved 0.7dB for female voice and 0.7dB for male voice respectively. Compared to the MPC, SNRseg of AC-MPC has been improved that I was able to control the distortion of the speech waveform finally. And so, I expect to be able to this method for cellular phone and smart phone using excitation source of low bit rate.

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참고문헌

  1. Ghaemmaghami,S.,Sridharan,S.:"Very low rate speech coding using temporal decomposition".IEE Electron. Lett.35(6), p456-457.1999 https://doi.org/10.1049/el:19990316
  2. LeBlanc,W.P., Bhattacharya,B.,Mahmoud, S.A.:"Efficient search and design procedures for robust multi stage vector quantization of LPC parameters for 4kbps speech coding". IEEE Trans. Speech Audio Process. p373-385. 1993 https://doi.org/10.1109/89.242483
  3. McCree, A.V., Barnwell, T.P.,: "A mixed excitation LPC vocoder model for low bit rate speech coding", IEEE Trans. Speech Audio Process, p242-250,1995 https://doi.org/10.1109/89.397089
  4. B.S.Atal and J.R.Remdo: "A New Medel of LPC Excitation for Producing Natural Sounding Speech at Low Bit Rates", IEEE, ICASSP, p614-617, 1982 https://doi.org/10.1109/ICASSP.1982.1171649
  5. Campbell, J.P., Tremain, T.E.: "Voiced/unvoiced classification of speech with applications to the U.S. Government LPC-10e algorithm", Proc.IEEE Int.Conf. on Acoustics, Speech, Sinal Processing, p473-476.1986 https://doi.org/10.1109/ICASSP.1986.1169060
  6. Kazunori OZAWA, Takashi ARASEKI: "Multi-Pulse Excited Speech Coding Utilizing Pitch Information at Rates Between 9.6 and 4.8 kbit/s", IEICE, Vol.J72-D-2, No.8, 1989
  7. Selma Ozaydm, Buyurman Baykal: "Matrix quantization and mixed excitation based linear predictive speech coding at very low bit ates", Speech Communication 41, p381-392, 2003 https://doi.org/10.1016/S0167-6393(03)00009-8
  8. K.Krishna, V.L.N.Murty, .R.Ramakrishnan: "Vector quantization of excitation gains in speech ding", Signal Processing 81, p203-209, 2001 https://doi.org/10.1016/S0165-1684(00)00200-0
  9. Nobuhiko KITAWAKI, Fumitada ITAKURA and Shuzo SAITO: "Optimum Coding of Transmission Parameters in PARCOR Speech Analysis Synthesis System", IEICE, Vol. J61-A No.2, 1978