Patent · US Expired

System for cancelling echo signals

US4937813A · kind A · utility

9Cited by
3References
11Claims
0Family size

Assignee

Inventor

Key dates

Filing dateFeb 16, 1988
Grant dateJun 26, 1990
Priority date
Expiry dateFeb 16, 2008

Classification

  • Technology area (CPC H)Electricity
  • CPC primaryH04B3/231
  • WIPO fieldTelecommunications
  • WIPO sectorElectrical engineering

Abstract

An adaptive compensator circuit is provided which includes a first echo compensator, responsive to data signals from the transmitter, for providing a first compensation signal for compensating an echo signal component which is linearly related to the digital signals to be transmitted. A second echo compensator, responsive to both the first compensation signal and the corrected received signal provides a second compensation signal for compensating the nonlinear echo signal component. An adder, responsive to the first and second echo compensation signals, provides a summed compensation signal. The data signals from the receiver are corrected by means of the summed compensation signal. In another embodiment, the second echo compensator is responsive to both the corrected received signal and the current symbol being transmitted by the transmitter and the (N-1) preceding symbols.

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