Method and apparatus for speech compression using multi-mode code excited linear predictive coding

Abstract

An apparatus and method of coding speech. The apparatus includes a first circuit being coupled to receive a first signal, the first signal corresponds to the speech signal. The first circuit is for generating a first set of parameters corresponding to the first frame. The apparatus includes a second circuit, being coupled to receive a second signal and the first set of parameters, the second signal corresponding to the speech signal, and the second circuit is for generating a third signal. The apparatus further includes a pulse train analyzer, being coupled to the second circuit, for generating a third match value, a third set of parameters, and a third excitation value. The apparatus further including a fourth circuit, being coupled to the second circuit, for generating a fourth match value, a fourth set of parameters, and a fourth excitation value. The apparatus further including a fifth circuit, being coupled to the third circuit and the fourth circuit, for selecting a mode corresponding to a match value. The apparatus further including a sixth circuit, being coupled to the fifth circuit, for selecting a selected set of parameters and a selected excitation corresponding to the mode. The apparatus further including a seventh circuit, being coupled to the first circuit and the sixth circuit, for generating an encoded signal responsive to the selected set of parameters and the mode.