가변 대역폭 필터를 이용한 음성신호의 AM-FM 성분 분리에 관한 연구

Decomposition of Speech Signal into AM-FM Components Using Varialle Bandwidth Filter

  • 송민 (전남대학교 공과대학 전자공학과) ;
  • 이희영 (전남대학교 공과대학 정보통신공학부)
  • 발행 : 2001.12.01

초록

Modulated components of a speech signal are frequently used for speech coding, speech recognition, and speech synthesis. Time-frequency representation (TFR) reveals some information about instantaneous frequency, instantaneous bandwidth and boundary of each component of the considering speech signal. In many cases, the extraction of AM-FM components corresponding to instantaneous frequencies is difficult since the Fourier spectra of the components with time-varying instantaneous frequency are overlapped each other in Fourier frequency domain. In this paper, an efficient method decomposing speech signal into AM-FM components is proposed. A variable bandwidth filter is developed for the decomposition of speech signals with time-varying instantaneous frequencies. The variable bandwidth filter can extract AM-FM components of a speech signal whose TFRs are not overlapped in timefrequency domain. Also, amplitude and instantaneous frequency of the decomposed components are estimated by using Hilbert transform.

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