Patent ID: 8073133
Filing Date: 2011-12-06
Classification: H04B

Abstract:
1. An echo canceler having an adaptive filter that generates an echo replica signal from filter coefficients and a far-end signal, and a subtractor that subtracts the echo replica signal from a near-end signal to remove an echo of the far-end signal in the near-end signal, leaving a residual error signal, the echo canceler comprising: a background noise estimator for estimating near-end background noise power from the residual error signal; and a step size calculator for using the estimated near-end background noise power to calculate a step size and supplying the step size to the adaptive filter to control adaptive updating of the filter coefficients in the adaptive filter; and wherein the step size calculator calculates the step size by the following formula, in which μ is the step size, n is a discrete time variable, x(n) is the far-end signal, b(n) is the estimated near-end noise power, and α, β, and γ are constants: