US 2011/0033059 A1 · METHOD AND SYSTEM FOR REDUCING ECHO AND NOISE IN A VEHICLE PASSENGER COMPARTMENT ENVIRONMENT

Abstract

An echo cancelling algorithm in a communication device initializes a step size value used in an adaptive echo filter based on a background noise signal power level relative to a power level of a received signal and a power level of an echo estimate relative to an output of an echo canceller. The algorithm then adjusts the step size value. One aspect adjusts the step size based on the detection of large fast fourier transform values at one, or more, disturbing-signal frequencies. Another aspect estimates residual echo energy to adjust an estimated echo energy, which then is used to set a double talk flag if a transmit signal has much more power than the estimated echo signal. Another aspect compares transmit signal power to a decimated version of the transmit signal power and sets the double talk flag if the former exceeds the latter by a predetermined amount.

Claims13

Dependent claims

A method for performing adaptive signal conditioning, comprising:

determining an initial value for a step size used in an adaptive filter algorithm based on:
a background noise signal power level relative to a power level of a received signal;
and
a power level of an echo estimate relative to an output of an echo canceller;
and
adjusting the step size value based on the detection of large fast fourier transform values at one, or more, disturbing-signal frequencies.

3 more elements

Dependencies are inferred from the claim text.

Method and system for reducing echo and noise in a vehicle passenger compartment environment

Life of this patent

Method and system for reducing echo and noise in a vehicle passenger compartment environment

Life of this patent

Abstract

Claims13