| 摘要 |
PURPOSE: A method and a device for canceling an echo of a telephone system are provided to detect near-end voice signals by the frame and to detect the near-end voice signals in every sample within a frame inside an echo canceller. So that a matter of misjudgement that near-end voice signals do not exist in some section where the near-end voice signals are started, can be solved and the echo canceller can be stably operated. CONSTITUTION: A near-end voice signal detector buffers near-end voice signals during one frame, and buffers far-end voice signals during one frame and adaptive filer coefficient. The near-end voice signal detector detects near-end voice signals every sample of the buffered near-end voice signals. The near-end voice signal detector decides whether a sample of a near-end voice signal exists. If the sample does not exist, the near-end voice signal detector decides that the frame does not have near-end voice signals. The near-end voice signal detector performs a coefficient updating operation of an adaptive filter and turns off a switch, to prevent an echo component from being delivered to an encoder. If the sample of the near-end voice signal exists, the near-end voice signal detector decides that the frame has near-end voice signals. The near-end voice signal detector performs a filtering operation of the adaptive filter and turns on the switch, to make the near-end voice signal delivered to the encoder.
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