Echo canceller with interference-level controlled step size
AssigneeST-Ericsson SA
InventorWolfgang Brox
Life of this patent
Estimating the term…
Abstract
Echo canceling method comprising the steps: a) receiving a first signal and a second signal, said second signal comprising an echo of the first signal, b) generating an echo replica signal by filtering the first signal with a finite impulse response filter, said finite impulse filter using a filter coefficient vector for generating the echo replica signal, generating an echo cancelled signal by subtracting the echo replica signal from the second signal, d) determining a measure of interference within the second signal, e) determining a step vector depending on said measure of interference, wherein increasing the measure of interference continuously reduces a size of the step vector, and f) updating the filter coefficient vector by the step vector.
Claims9
Echo canceling method comprising the steps:
- a) receiving a first signal and a second signal, said second signal comprising an echo of the first signal,
- b) generating an echo replica signal by filtering the first signal with a finite impulse response filter, said finite impulse filter using a filter coefficient vector for generating the echo replica signal,
- c) generating an echo cancelled signal by subtracting the echo replica signal from the second signal,
- d) determining a measure of interference within the second signal,
- e) determining a step vector depending on said measure of interference, wherein increasing the measure of interference continuously reduces a size of the step vector, and
- f) updating the filter coefficient vector by the step vector.
Echo canceling device comprising:
- a finite impulse response filter adapted to receive a first signal and to output an echo replica signal, said finite impulse response filter using a filter coefficient vector for generating the echo replica signal,
- a subtraction circuit for subtracting the echo replica signal from a second signal comprising an echo of the first signal,
- a coefficient update circuit for iteratively updating the filter coefficient vector by a step vector,
- a means for determining a measure of interference within the second signal,
- a means for determining the step vector depending on the measure of interference, wherein increasing the measure of interference continuously reduces a size of the step vector.
Dependencies are inferred from the claim text.