An adaptive echo cancellation method against shock interference

Abstract

A M estimation decorrelation proportional adaptive echo cancellation method for resisting impulse noise interference is disclosed, which comprises the following steps: A, collecting far-end signals, sampling far-end signals transmitted from far-end, and obtaining the discrete value x (n) of far-end input signals at the current time n, the filter input signal vector being x (n) = [x (n), x (n); 1),..., x (n- L+1)]T; B, estimating an echo signal, passing an input signal vector x (n) at a time n through an adaptive filt, and outputting a value y (n) thereof, that is, an estimated value of the echo signal; C, performing decorrelation operation of input signal, calculating correlation coefficient a (n), obtaining update vector z (n) of tap weight vector w (n) of adaptive filter; D, cancelling echo, wherein that near-end signal d (n) at the current time n of the echo return is sampled by a near-end microphone and the estimate value y (n) of the echo signal is subtracted; E, updating the tapweight coefficient of the filter, calculating an evaluation function psi (e (n)) updated by the tap weight vector w (n) of the filter at the current time n and updating a step size matrix G (n); F, setting n=n+1, repeating the proces of A, B, C, D, E until the end of the call.

Description

technical field [0001] The invention belongs to the technical field of echo cancellation in communication systems. technical background [0002] Adaptive signal processing technology has a wide range of applications in the field of communication. The signals in the communication system are mainly voice signals, however, when a call is in progress, the echo will seriously affect the quality of the voice call. The echo phenomenon refers to the sound or signal being reflected back to the signal source after delay or deformation. This phenomenon widely exists in communication systems such as voice communication, data communication, satellite communication, hands-free phone, and teleconferencing system. For example, when making a phone call, because the speaker and the microphone are placed in the same space, the local near-end microphone will receive the far-end voice from the local speaker and send it back to the far end, which will cause the far-end speaker to hear his own v...

AI Technical Summary

Problems solved by technology

Among the product influence factors considered when the tap weight vector is updated in this algorithm, the influence factor related to the residual is directly the residual signal at the current moment. When there is impact interference, the "residual signal" is huge, resulting in the wrong tap weight vector. Huge update, reduced convergence speed, increased steady-state error, and still can't achieve good results when it resists impact interference

Images