Self-adaptive echo eliminator and echo eliminating method thereof

Abstract

The invention provides an adaptive echo eliminator and the echo eliminating method thereof; wherein the device consists essentially of a voice state detector, an NLMS (energy normalized least mean square error) controller and a sliding window FIR filter. The method mainly includes the following steps: sampling both a far-end voice signal and a near-end voice signal, and confirming the speaking status information of the current network according to the estimated values of the short-time energy of the sampled far-end speech signal sample and the near-end speech signal sample. Then, the coefficient of a sliding window FIR filter is configured according to the speaking status information of the current network, and the sliding window FIR filter step-by-step filters the near-end speech signal and the far-end speech signal filled into the buffer area according to the mobile length set by the configured coefficient. Utilizing the invention, the echo of the digital hands-free speaking system can be effectively eliminated, thereby effectively eliminating the echo of the digital communication system based on the embedded system.

Description

technical field [0001] The invention relates to the communication field, in particular to an adaptive echo canceller and an echo canceling method thereof. Background technique [0002] Delay and echo are the main factors affecting the quality of communication. Excessive delay can make the echo problem more prominent, which will eventually lead to the failure of normal communication. Therefore, in the communication link, as long as the delay of one-way voice transmission reaches more than 10ms, echo cancellation is required. At present, the end-to-end delay of digital voice communication systems using compression algorithms based on packet transmission exceeds the threshold of 10 ms, and the above-mentioned digital voice systems all need to use echo cancellers for echo cancellation. [0003] At present, the International Telecommunications Union has released a series of international standards on echo cancellation technology, such as: G.165, G.167, G.168 and so on. However,...

AI Technical Summary

Problems solved by technology

In an embedded system, such large-scale shift operations are time-consuming

[0038] 4. When the echo delay is large, the order N of the adaptive filter will increase accordingly, and the convergence speed will decrease, which will cause the convergence time to fail to meet real-time requirements and increase the amount of computation

[0039] 5. The operation of generating comfort noise in NLP also increases the amount of calculation and complexity to a certain extent

[0040] In view of the above problems, although the above-mentioned existing echo cancellation processing system is theoretically feasible, it cannot meet the real-time requirements of the embedded system, nor can it adapt to the limitation of the limited system resources of the embedded system, and cannot be truly commercialized.

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