Shrinkage variable step length sub-band echo cancellation method

Abstract

The invention discloses a shrinkage variable step length sub-band echo cancellation method, and the method comprises the steps: A, signal sampling and processing: segmenting an input vector U(n) into I far-end sub-band vectors Ui(n) through a first analysis filter, enabling a near-end signal d(n) picked by a near-end microphone to be segmented into I near-end sub-band signals di(n) through a second analysis filter, carrying out the I extraction of a far-end input sub-band vector Ui(n) through an extractor, obtaining far-end input sub-band extraction vectors Ui(k), and, similarly, carrying out the I extraction of the near-end sub-band signals di(n) through the extractor, and obtaining near-end sub-band extraction signals di(K); B, filter outputting: enabling the far-end input sub-band extraction vectors Ui(k) to pass through a sub-band filter in an adaptive echo cancellation filter, obtaining output sub-band signals yi(k); C, echo cancellation; D, the updating of a weight coefficient vector: obtaining an updating step length [Mu]i(k) of the weight coefficient vector of the sub-band filter based on a denoising near-end signal square estimation quantity; E, the supposing: k is equal to (k+1), and the repeated execution of steps A, B, C and D till the conversation is ended. The method can obtain a higher rate of convergence and a lower stable error.

Description

technical field [0001] The invention belongs to the technical field of adaptive echo cancellation for voice communication. Background technique [0002] At present, the echo canceller estimates the echo through the core component—adaptive filter, and subtracts the estimated value of the echo from the near-end signal to achieve the effect of echo cancellation. Adaptive echo cancellation technology has been unanimously recognized because of its low cost and good effect, and it is also one of the most promising echo cancellation technologies recognized internationally. [0003] From the basic principle of echo cancellation, the use of acoustic echo canceller to achieve echo cancellation, the core part of which is the adaptive filter. The least mean square (LMS) algorithm, which is most commonly used in adaptive systems, often cannot achieve good results in echo cancellation applications. For this reason, in order to solve this difficulty, the method of normalized sub-band ada...

AI Technical Summary

Problems solved by technology

In the current adaptive echo cancellation application, the more mature subband method is the adaptive filtering algorithm of the normalized subband class, such as the literature 1 "Variableregularization parameter sign subband adaptive filter" (J.Ni and F.Li, Electron.Lett., vol.46, no.24, pp.1605–1607, Nov.2010.)'s (SSAF) method, which is to add the symbolic subband (SSAF) algorithm to the variable regularization parameter strategy to reduce the fixed The influence of the step size on the convergence speed and steady-state error, this method is the step size of the skip line, the step size change is only related to time, the longer the time, the smaller the step size; therefore, when the application conditions change or the application In the case of unstable conditions, the performance of the algorithm will decrease

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