Patent ID: 6199040
Filing Date: 2001-03-06
Classification: G10L

Abstract:
A system for communicating an encoded speech signal comprising:a transmitter for generating a perceptually encoded speech spectrum signal; anda receiver for decoding the perceptually encoded speech spectrum signal;wherein the transmitter further includes:a speech analyzer for generating a parameterized speech signal comprised of a plurality of vectors for a codebook; anda vector quantizer for generating the perceptually encoded speech spectrum signal from the parameterized speech signal, wherein said vector quantizer performs a subtraction operation for first adjacent terms for each of the plurality of vectors for the codebook, compares results for the subtraction operation for the first adjacent terms to determine differences between the first adjacent terms for each of the plurality of vectors, assigns each of the plurality of vectors to at least one of a set of sub-codebooks based on the differences between the first adjacent terms for each of the plurality of vectors, assigns a vector to a sub-codebook based on differences between second adjacent terms for the vector, compares the vector with each of a second plurality of vectors representing the sub-codebook to determine which one of the second plurality of vectors is perceptually closest to the vector, and substitutes the one for the vector.