Patent · US Expired

Transversal filter useable in echo canceler, decision feedback equalizer applications for minimizing non-linear distortion in signals conveyed over full duplex two-wire communication link

US5526377A · kind A · utility

12Cited by
8References
14Claims
0Family size

Assignee

Inventors

Key dates

Filing dateDec 12, 1994
Grant dateJun 11, 1996
Priority date
Expiry dateDec 12, 2014

Classification

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

Abstract

The need to employ costly precision components to reduce non-linearities in the signal processing path of noise reduction circuitry such as an echo canceler and decision feedback equalizer is successfully addressed by a transversal filter which is capable of effectively tracking for non-linearities in system components that manifest themselves as added noise introduced into the signal propagation path. This non-linear tracking capability is attained by employing cascaded sets of weighting coefficient and scaling factor multiplying stages. The first set of weighting coefficients effectively modifies the contents of each of the transmitted symbol samples in the transversal filter delay line to produce respective sets of `partial sums` associated with the respective data symbols employed in the data modulation scheme. The second, cascaded set of `scaling` coefficients or factors is employed to scale selected ones of the sets of the partial sums.

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