Motorola Corporation

Ernest Pei-Ching Chen

James Brian Piket

William Chunhung Yip

James A Stephens

Christopher W Springfield

The step sizes for tap positions of an adaptive filter ( ) in an echo canceller ( ) for canceling an echo signal are individually selected based upon a profile of the echo environment. A training signal ( ) is injected into the echo canceller and to the echo path during a training interval, or period. The adaptive filter profiles the echo path during the training interval. Respective step sizes &agr;&lsqb;k&rsqb; for the tap positions are generated as a function of the echo profile so generated.

Method and apparatus for setting a step size for an adaptive filter coefficient of an echo canceller

A communications transmitter which operates as a mobile telephone incorporates a noise suppressor ( FIG. ) which reduces the background noise in the transmitted voice signal. An external voice activity detector ( ), which operates in conjunction with a noise suppressor ( ) estimates the signal power of the incoming voice signal and compares this to an estimated noise floor. As a result of this comparison, a voice activity factor is applied to an updated noise floor estimate to create a voice activity threshold estimate. The voice activity threshold estimate is then used to decide whether or not to the force noise suppressor ( ) to perform an update of a noise content estimate of the incoming voice signal.

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Gilbert, AZ, United States of America

Ernest Pei-Ching Chen