Patent · US Expired

Decision feedback equalizers, methods, and computer program products for detecting severe error events and preserving equalizer filter characteristics in response thereto

US6341360B1 · kind B1 · utility

36Cited by
136References
18Claims
0Family size

Assignee

Inventors

Key dates

Filing dateMar 8, 1999
Grant dateJan 22, 2002
Priority date
Expiry dateMar 8, 2019

Classification

  • Technology area (CPC H)Electricity
  • CPC primaryH04L2025/03694
  • WIPO fieldDigital communication
  • WIPO sectorElectrical engineering

Abstract

Decision feedback equalizers having a stabilization capability, and methods and computer program products for stabilizing a decision feedback equalizer under severe error conditions use output samples from an equalizer to determine whether a severe error event has occurred in accordance with predefined criteria. If a severe error occurs, then a determination is made to evaluate whether the number of severe errors that have occurred has exceeded a threshold. If the threshold has been exceeded, then the coefficients for the filter(s) in the decision feedback equalizer are preserved in their current state. Severe errors can cause the equalizer filter coefficients to be pulled away from their normal operating values, which can result in several modulation cycles passing before the coefficients are restored. By preserving the equalizer filter coefficients under severe error conditions, the present invention prevents sharp or dramatic changes to the coefficient values from their steady state values allowing the decision feedback equalizer to recover more quickly from the errors.

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