An Affine Projection Maximum Entropy Subband Adaptive Echo Cancellation Method

Abstract

A kind of affine projection maximum entropy sub-band adaptive echo cancellation method, its steps are: A, far-end signal segmentation, the far-end signal vector U (n) is divided into 1 far-end sub-band vector U through analysis filter i (n), at the same time, the near-end signal d(n) picked up by the near-end microphone is divided into 1 near-terminal band signals d through the analysis filter i (n); B, signal extraction, the remote terminal with vector U i (n) carry out I extraction through extractor; Obtain far-end input sub-band extraction vector U i (k); also for near terminal with signal d i (n) I extraction is performed by the extractor to obtain the near-terminal strip extraction signal d i (k); C, affine projection, D, filter output, the far-end input subband affine projection matrix X(k) is filtered by a filter to obtain an output vector Y(k); E, echo cancellation, F, The tap weight vector is updated, based on the maximum entropy V(k) update of the current net signal vector to determine the weight vector at the next extraction moment, G, iteration, let k=k+1, repeat A, B, C, D, E, Step F, until the end of the call. It has good echo cancellation effect and strong anti-interference ability.

Description

technical field [0001] The invention belongs to the technical field of adaptive echo cancellation for voice communication. Background technique [0002] In order to solve the problem of system echo interference during communication, various echo cancellation methods have been proposed. At present, echo cancellation methods mainly include frequency shift technology, sub-band center clipping technology, voice control switch technology, comb filter technology, microphone array technology, and adaptive echo cancellation technology. The first five methods have disadvantages such as high cost and difficult design. The adaptive echo cancellation method is not only low in cost, but also can obtain good performance. Therefore, the adaptive echo cancellation method is currently the mainstream echo cancellation technology. [0003] In the adaptive echo cancellation technology, the adaptive filter is a digital filter that can automatically adjust the performance according to the input...

AI Technical Summary

Problems solved by technology

However, when the algorithm converges, the algorithm weight vector is updated only through the sign of the error signal (positive or negative), regardless of the size of the error signal, so that although it has good anti-impulse interference ability, its convergence speed needs improvement

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