Patent · US Expired

Echo canceller with adaptive and non-adaptive filters

US5664011A · kind A · utility

52Cited by
9References
27Claims
0Family size

Assignee

Inventors

Key dates

Filing dateAug 25, 1995
Grant dateSep 2, 1997
Priority date
Expiry dateAug 25, 2015

Classification

  • Technology area (CPC H)Electricity
  • CPC primaryH04B3/23
  • WIPO fieldTelecommunications
  • WIPO sectorElectrical engineering

Abstract

An echo canceller includes receive and send paths each having an input and output port, a first non-adaptive filter with first filter coefficients for generating a first replica signal in response to a receive input signal, a second adaptive filter with second filter coefficients for generating a second replica signal in response to the receive input signal, a first subtracter for generating a send output signal representing a difference between a send input signal and the first replica signal, a second subtracter for generating an error signal representing a difference between the send output signal and the second replica signal, and a controller for replacing the first filter coefficients by the sum of the first and second filter coefficients and for resetting the second filter coefficients in response to a calculation that includes a first quantity associated with the send output signal and a second quantity associated with the error signal.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.