Digital modem echo canceler enhancement

摘要

A modem-based echo cancellation enhancement for digital communications networks is provided. The effects on echo cancellation of non-linearity in a far end echo path in a digital telephone system are reduced by introduction of non-linearities into the near end signal prior to generation of the echo cancellation signal. Near end signal is sampled after linear to PCM conversion. A PCM to linear conversion is added prior to the echo canceler. The near end delay line can be provided between the converters to delay the signal as PCM samples, thereby reducing delay line memory requirements.