Patent ID: 6950842

Claim:
An echo canceller adapted for use in a communication system that includes a hybrid circuit, said echo canceller comprising: an adaptive digital filter that generates an estimated echo signal {circumflex over (z)}[k] in response to (i) a sampled input data sequence x[k] and (ii) an error signal sequence e[k] indicative of the difference between a near end signal sequence y[k] and the estimated echo signal {circumflex over (z)}[k], wherein said adaptive digital filter computes filter coefficients based upon said error signal sequence e[k] using a stochastic quadratic descent estimator that employs a dynamically adjustable step size vector μ [k] and said adaptive digital filter comprises means for computing said dynamically adjustable step size vector μ [k] of the form μ _ ⁡ [ k + 1 ] = μ _ ⁡ [ k ] + α ⁢ ⁢ ϕ _ ⁡ [ k ] · x _ ⁡ [ k ] ⁢ e ⁡ [ k ] ⁢ | μ min μ max , where φ [k+1]= φ [k]•( 1 − μ [k]• x 2 [k])+e[k] x [k] and α is a scalar.