On the behaviour of reduced complexity code-excited linear prediction (CELP)

In this paper, we propose a simplification of the model introduced by B.S. Atal and M.R. Schroeder for a code-excited linear predictor. Our scheme is based on a two-step search of the optimum code-word. In the first step, a sub-set in the code-book is selected by using a simple distance measure and taking into account the selections already made for the previous frames of speech. In the second step, the original model of Atal and Schroeder, including perceptual weighting, is applied to the sub-set in order to make the final selection of the optimum code-word. The proposed scheme reduces the computational load involved in the original one, and our preliminar results indicate that the quality of the synthetic speech is fairly good.