Digital adaptive filter and acoustic echo canceller using the same

Digital adaptive filter and acoustic echo canceller using the same

  • CN 100,531,274 C
  • Filed: 07/01/1999
  • Issued: 08/19/2009
  • Est. Priority Date: 07/13/1998
  • Status: Active Grant
First Claim
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1. digital adaptive filter, it is used for simulating the signal path between hands-free type communication equipment loud speaker and the microphone, and this filter comprises:

  • The filter coefficient update device, in order to by the estimative power of input signal, this input signal and in this digital adaptive filter filtered input signal and bring in constant renewal in filter coefficient along the error signal between the input signal of propagating by the external path of this digital adaptive filter simulation;

    WithThe input signal power estimation unit, be used for by the input signal power level of the input signal power level that increases and minimizing is come that with different weighting factors the input power of the input power that increases and/or minimizing is carried out asymmetric recursion smoothly, wherein to press following formula level and smooth to input power implementation recursion for this input signal power estimation unit;

    PI| t

    β

    ·

    Pin| t+(1-β



    PI| t-1

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