Patent ID: 6961718

Claim:
A system for processing a sequence of input vectors, said input vectors each comprising a plurality of elements, and said system comprising: a digital filter with a filter vector input for receiving said sequence of input vectors obtained from a digitized speech signal and a predictor gain input for controlling characteristics of said filter, said digital filter also having both a current slowly evolving filter estimate output and a previous slowly evolving filter estimate output, said current slowly evolving filter estimate output providing a current filtered estimate value of a slowly evolving component of said sequence of input vectors and said previous slowly evolving filter estimate output providing a previous filtered estimate value of said slowly evolving component of said sequence of input vectors; a parameter estimator having an estimator vector input for receiving said sequence of input vectors and a previous slowly evolving filter estimate input coupled to said previous slowly evolving filter estimate output, said parameter estimator further includes a predictor gain output coupled to said predictor gain input; a smoother module having inputs coupled respectively to at least two outputs of said digital filter, said smoother module having a smoothed estimate output providing a smoothed estimate value of a said previous slowly evolving component; and a slowly evolving component encoder with an input coupled to said smoothed estimate output, wherein when said system receives a current input vector that is one of said sequence of said input vectors, said parameter estimator provides a current predictor gain value at said predictor gain output thereby modifying both paid current filtered estimate value at said current slowly evolving filter estimate output and said smoothed estimate value, said current predictor gain value being dependent upon both said previous filtered estimate value received at said slowly evolving filter estimate input and said current input vector received at said estimator vector input, and wherein the slowly evolving component encoder processes said smoothed estimate value to provide a digitized encoded slowly evolving component of the speech signal.