Patent US 5,699,482

A method of encoding a speech signal is provided. This method improves the excitation codebook and search procedure of the conventional Code-Excited Linear Prediction (CELP) speech encoders. This code is based on a sparse algebraic code consisting in particular, but not exclusively, of interleaving N single-pulse permutation codes. The search complexity in finding the best codeword is greatly reduced by bringing the search back to the algebraic code domain thereby allowing the sparsity of the algebraic code to speed up the necessary computations. More precisely, the sparsity of the code enable the use of a very fast procedure based on N-embedded computation loops.