Spectral widening of the excitation signal for telephone-band speech enhancement

In current telephone systems the speech to be transmitted is band-limited. The resulting speech quality degradation can be reduced by supplementing the missing spectral components of an enlarged frequency band in an artificial way. One important component of an enhancement system is the wide-band synthesis-filter that has to be driven with a wide-band excitation signal. The focus of this paper is to propose different methods to generate this wide-band excitation signal from a telephone-band limited version.

[1]  Peter Jax,et al.  Wideband extension of telephone speech using a hidden Markov model , 2000, 2000 IEEE Workshop on Speech Coding. Proceedings. Meeting the Challenges of the New Millennium (Cat. No.00EX421).

[2]  Julien Epps,et al.  A new technique for wideband enhancement of coded narrowband speech , 1999, 1999 IEEE Workshop on Speech Coding Proceedings. Model, Coders, and Error Criteria (Cat. No.99EX351).

[3]  John Makhoul,et al.  High-frequency regeneration in speech coding systems , 1979, ICASSP.

[4]  Cheung-Fat Chan,et al.  Quality enhancement of narrowband CELP-coded speech via wideband harmonic re-synthesis , 1997, 1997 IEEE International Conference on Acoustics, Speech, and Signal Processing.

[5]  Willem Bastiaan Kleijn,et al.  Bandwidth expansion of speech based on vector quantization of the mel frequency cepstral coefficients , 1999, 1999 IEEE Workshop on Speech Coding Proceedings. Model, Coders, and Error Criteria (Cat. No.99EX351).