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

The Korea Academia-Industrial cooperation Society (한국산학기술학회)
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A Study on Compensation of Amplitude in Multi Pulse

멀티펄스의 진폭보정에 관한 연구

  • Lee, See-Woo (Dept. of Information and Telecommunication Engineering, Sangmyung University)
  • 이시우 (상명대학교 정보통신공학과)
  • Received : 2011.05.31
  • Accepted : 2011.09.08
  • Published : 2011.09.30
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Abstract

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.

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.

Keywords

References

  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