A Modified CELP Model with Computationally Search Efficient Adaptive Codebook
Lficio Martins da Silva, Abraham Alcaim · 1995
In this letter, we propose a CELP algorithm in which the complexity of the search procedure in the adaptive codebook is greatly reduced. This is achieved by means of a modified model of the CELP synthesizer, while keeping the usual perceptual weighting of the synthesis error in the analysis procedure. Simulation results show that the proposed algorithm can provide speech quality comparable to the one obtained with the conventional CELP codec. G2 HE adaptive codebook (CB) search ( 11 is responsible for T a significant quota of the complexity of conventional CELP techniques (2). In this paper, we propose a CELP algorithm with a modified synthesis model, for which the analysis-by-synthesis procedure does not require filtering the candidate excitation sequences of the adaptive CB. The pro- posed CELP scheme considerably reduces the computational effort of the search procedure in the adaptive CB, while providing a reconstructed speech quality that is comparable to the one obtained with conventional CELP.