A Proportional Affine Projection Echo Cancellation Method Based on Convex Combination Coefficient Difference

Abstract

A proportional affine projection echo cancellation method of a convex combination coefficient difference, the steps are: A, far-end sampling signal filtering, A1, far-end discrete input signals constitute the input vector X of the convex combination adaptive filtering echo cancellation filter (n); A2, input the filter vector X(n) to obtain the filter value y with a large step size and a small step size 1 (n) and y 2 (n); B, echo cancellation, subtracting the near-end signal d(n) from the combined filter output value y(n) to obtain the total residual signal e(n) after echo cancellation, and send it back to the far-end; C , convex combination, the large and small step size output value y 1 (n) and y 2 (n) Convex combination by weight λ(n) to obtain combined output value y(n), and its tap weight coefficient W 1 (n) and W 2 (n) Carry out convex combination by weight λ(n) to obtain tap filter tap weight coefficient W(n); D, filter tap weight vector update; E, filter weight update; F, filter weight limit G, repeat A , B, C, D, E, F steps, you can achieve echo cancellation. The method has strong identification ability, fast convergence speed, strong tracking ability, low steady-state error, and good echo cancellation effect.

Description

technical field [0001] The invention belongs to the technical field of communication self-adaptive echo cancellation, in particular to the technical field of proportional affine projection echo cancellation. Background technique [0002] With the development of communication technology, more and more communication devices provide hands-free function, which makes communication more convenient, but also produces echo problems, which will seriously affect the quality of voice calls and the stability of the system. For current communication systems (including wired telephones, hands-free telephones, mobile phones and teleconferencing systems, etc.), echo cancellation is one of the key factors that need to be considered in the design of these systems. Echo cancellation is to input the far-end signal with echo into the adaptive filter to realize the system identification of the unknown echo channel, that is, through the adjustment of the adaptive filtering algorithm, the echo path...

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Problems solved by technology

However, when the algorithm increases the step size, more data is lost, resulting in a large steady-state error.

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