Linear echo cancellation method and device thereof

Abstract

The invention relates to the field of communications, and discloses a linear echo cancellation method and device thereof, and can be used for improving the linear echo cancellation efficiency. The linear echo cancellation method comprises the following steps: respectively analyzing a reference signal and a near-end signal with a whole band into reference signals and near-end signals with N sub-bands, wherein N is an integer greater than 1; performing adaptive filtering on the reference signals with the N sub-bands to obtain estimated echo signals with the N sub-bands; subtracting the near-end signals with the N sub-bands by the estimated echo signals with the N sub-bands to obtain residual signals with the N sub-bands; and performing integrated filtration on the residual signals with the N sub-bands to obtain a residual signal with the whole band, wherein the residual signal with the whole band is a signal subjected to linear echo cancellation. The linear echo cancellation is used for cancelling echoes.

Description

technical field [0001] The invention relates to the communication field, in particular to a linear echo cancellation method and a device thereof. Background technique [0002] In people's daily life and work, mobile phones have become an indispensable tool. With the development of multimedia audio technology, people have higher and higher requirements on the audio performance of mobile phones. However, the echo and noise received by the microphone of the mobile phone will affect the call quality of the mobile phone. For the echo and noise received by the microphone of the mobile phone in the wireless environment, the echo cancellation technology can be used to eliminate it, thereby providing users with better call quality. [0003] At present, the technology for implementing adaptive linear echo cancellation is mainly based on NLMS (Normalized least mean square, normalized least mean square error). In the existing NLMS, calculating and processing an echo signal requires a...

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Problems solved by technology

[0004] In NLMS, the adaptive filter is updated according to the steepest descent method. Updating the adaptive filter means recalculating the adaptive filter coefficient vector. The change speed of the adaptive filter coefficient vector is affected by the step size factor, and the step size The factor is used to control the changing speed of the adaptive filter coefficients. Theoretically speaking, the step size factor is affected by the instantaneous energy of the near-end speech signal and the near-end noise signal. However, in the time-domain full-band processing, the near-end The near-end speech signal and the near-end noise signal fluctuate rapidly. In the mixed signal of the near-end speech, noise and echo, extracting the near-end speech signal energy and noise energy respectively requires a very complicated algorithm. Therefore, the time-domain full-band processing is used The step factor estimated by the method often deviates greatly from its theoretical value

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