Complexity reduction of CELP speech coders through the use of phase information

An efficient search procedure for CELP coders is described. Based on the phase spectra of the codevectors and the ideal excitation vector, a subset of the codebook is preselected. This subset is then exhaustively searched to find the best, perhaps optimum, codevector. Computational savings of the order of 30-40 are achieved while still maintaining good output speech quality.<
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