Patent ID: 7590527
Filing Date: 2009-09-15
Classification: G10L

Abstract:
1. A speech coder using an orthogonal search, by calculating a term of a search reference value, the speech coder comprising: an adaptive codebook that generates an adaptive codevector representing a pitch component; a random codebook that generates a random codevector representing a random component; a synthesis filter that generates a synthetic speech signal by the synthesis filter being excited by the adaptive codevector and the random codevector; and a distortion calculator that calculates a distortion between an input speech signal and the synthetic speech signal, and selects one random codevector that minimizes the distortion, wherein the distortion calculator calculating the term comprises: a system that computes the power, p a system that calculates a second matrix, M, by providing a time reverse synthesis, r a system that calculates a third matrix, L=N−M, by using the first matrix and the second matrix; and a system that calculates the term with reference to the third matrix, and wherein p is the adaptive codevector, H is the synthesis filter coefficient matrix, and t denotes transpose.