Adaptive bit allocation scheme in predictive coding of speech

Masaaki Honda, Nobuhiko Kitawaki, Fumitada Itakura

研究成果: Conference article査読

11 被引用数 (Scopus)


An adaptive predictive coding with adaptive bit allocation (APC-AB) is presented for speech encoding at low to medium bit rates (6.4kb/s-24kb/s). In this system, a split-band predictive coding scheme and a bit allocation scheme are employed in order to remove the redundancies due to a periodic concentration of the prediction residual energy as well as nonuniform nature of the speech spectrum. Quantization bits are dynamically allocated both over the sub-bands(frequency domain) and over the subintervals(time domain) in accordance with the distribution of the residual energies in the time-frequency domain. Optimum bit allocation is derived based on the mean square error criterion on the speech waveform, and the SNR gain is presented in relation to the prediction gain of the full-band signal. This system is evaluated in terms of the segmental SNR and speech quality. The result shows that the APC-AB system has advantage over the conventional full-band APC system in the segmental SNR and the stability of the prediction loop. It was also shown that this system can provide speech quality subjectively equivalent to 7 bit Log-PCM at 16 kb/s, and to 6 bit Log-PCM at 9.6 kb/s.

ジャーナルICASSP, IEEE International Conference on Acoustics, Speech and Signal Processing - Proceedings
出版ステータスPublished - 1982 1月 1
イベント1982 IEEE International Conference on Acoustics, Speech, and Signal Processing, ICASSP 1982 - Paris, France
継続期間: 1982 5月 31982 5月 5

ASJC Scopus subject areas

  • ソフトウェア
  • 信号処理
  • 電子工学および電気工学


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