Patent ID: 6510225
Filing Date: 2003-01-21
Classification: H04B,H04M

Abstract:
A fast-start adaptive echo canceller for a wireless system comprising:at least one speaker for converting an input signal to audible sound; at least one microphone for picking up desired voice signal, placed such that said at least one microphone also picks up an echo of said input signal resulting in a combined signal; an echo cancelling synthesizer, operating to synthesize a replica of an echo of said input signal based on echo-cancelling coefficients indicative of an environment and to cancel at least a part of said echo of said input signal; at least one ultrasonic transceiver for transmitting an ultrasound signal and receiving an echo of said ultrasound signal; a nonvolatile memory, storing previously-obtained ultrasonic echoes correlated with echo-cancelling coefficients used; and a selection element, said selection element including a controller and a memory, selecting a previously-used set of coefficients based on said ultrasonic echo.