High temporal resolution in multi-pulse coding

A CELP (code-excited linear predictive) coder using code books populated with pulses generated using a higher time resolution than a classical multi-pulse system is proposed. The pulses in the code book are generated as sampled sinc pulses, which are allowed to attain their corresponding maximum values at positions not necessarily equal to sample positions. The proposed code book performs equally well as CELP coders using multipulse code books in terms of robustness toward corrupted speech. However, the speech obtained is smoother, and the number of pulses required per subblock can be reduced without degrading the speech quality. A preliminary estimation of the bit rate required indicates that a reasonable choice lies in the range 8-9 kb/s.<<ETX>>

[1]  B. Atal,et al.  Strategies for improving the performance of CELP coders at low bit rates (speech analysis) , 1988, ICASSP-88., International Conference on Acoustics, Speech, and Signal Processing.

[2]  Manfred R. Schroeder,et al.  Code-excited linear prediction(CELP): High-quality speech at very low bit rates , 1985, ICASSP '85. IEEE International Conference on Acoustics, Speech, and Signal Processing.

[3]  Per Hedelin.  High quality glottal LPC-vocoding , 1986, ICASSP '86. IEEE International Conference on Acoustics, Speech, and Signal Processing.

[4]  Hiroya Fujisaki,et al.  Proposal and evaluation of models for the glottal source waveform , 1986, ICASSP '86. IEEE International Conference on Acoustics, Speech, and Signal Processing.

[5]  Per Hedelin,et al.  Code-book driven glottal pulse analysis , 1989, International Conference on Acoustics, Speech, and Signal Processing,.

[6]  Ed F. Deprettere,et al.  A class of analysis-by-synthesis predictive coders for high quality speech coding at rates between 4.8 and 16 kbit/s , 1988, IEEE J. Sel. Areas Commun..

[7]  Bishnu S. Atal,et al.  A new model of LPC excitation for producing natural-sounding speech at low bit rates , 1982, ICASSP.

[8]  J.-P. Adoul,et al.  A comparison of some algebraic structures for CELP coding of speech , 1987, ICASSP '87. IEEE International Conference on Acoustics, Speech, and Signal Processing.

[9]  K. Ozawa,et al.  2.4 kbps pitch prediction multi-pulse speech coding , 1988, ICASSP-88., International Conference on Acoustics, Speech, and Signal Processing.

[10]  John E. Markel,et al.  Linear Prediction of Speech , 1976, Communication and Cybernetics.

[11]  M.G. Bellanger,et al.  Digital processing of speech signals , 1980, Proceedings of the IEEE.

[12]  Thomas P. Barnwell,et al.  The self excited vocoder - an alternate approach to toll quality at 4800 bps , 1986, ICASSP '86. IEEE International Conference on Acoustics, Speech, and Signal Processing.