System for search of a codebook in a speech encoder

Abstract From the Canadian patent

A speech encoder synthesizes an excitation sound source in accordance with the linear coupling of at least two predetermined basis vectors. I n realizing the codebook search by using signal processing LSIs, the ordination of the first cross correlation Rm between an input speech signal p(n) and plural reproduced signals obtained by using plural basis vectors is computed, and the ordination of the second cross correlation Dmj of the plural reproduced signals qm(n) is computed. These ordinations are arranged to be one ordination Rdmj. By using the ordination Rdmj all possible combinations of the third and fourth cross correlation calculations are carried out to provide a most optimum …