SPEECH ENCODING/DECODING METHOD AND APPARATUS USING LPC RESIDUALS

摘要

A speech encoding method and apparatus in which an input speech signal is divided in terms of blocks or frames as encoding units and encoded in terms of the encoding units, in which explosive and fricative consonants can be impeccably reproduced, while there is no risk of foreign sound being generated at a transient portion between voiced (V) and unvoiced (UV) portions, so that the speech with high clarity devoid of "stuffed" feeling may be produced. The encoding apparatus includes a first encoding unit 110 for finding residuals of linear predictive coding (LPC) of an input speech signal for performing harmonic coding and a second encoding unit 120 encoding the input speech signal by waveform coding. The first encoding unit 110 and the second encoding unit 120 are used for encoding a voiced (V) portion and an unvoiced (UV) portion of the input signal, respectively. The constitution of a code excited linear prediction (CELP) encoding employing vector quantization by a closed loop search of an optimum vector using an analysis-by-synthesis method is used for the second encoding unit 120.