A CELP codebook and search technique using a Hopfield net

A ternary excitation codebook with a special structure for CELP (code-excited linear prediction) coding has been devised in which the main codebook is divided into several sub-codebooks. It is shown how a modified Hopfield neural net is capable of searching such a codebook and selecting a near-optimum code vector. Hence an algorithm is derived which offers considerable computational savings over previously proposed codebook methods. Results are presented demonstrating the performance of the net and the quality of the coded speech. >