Patent · US Expired

Adaptive IF equalizer for digital transmission

US4430744A · kind A · utility

8Cited by
6References
8Claims
0Family size

Assignee

Inventor

Key dates

Filing dateDec 18, 1981
Grant dateFeb 7, 1984
Priority date
Expiry dateDec 18, 2001

Classification

  • Technology area (CPC H)Electricity
  • CPC primaryH04B3/141
  • WIPO fieldTelecommunications
  • WIPO sectorElectrical engineering

Abstract

A radio signal will often suffer from amplitude and group delay distortion caused by multipath fading. An adaptive equalizer, which effectively cancels the amplitude distortion effects, is based upon the use of control voltages derived from selected portions of the IF band; the control voltages being selectively applied to bump and slope equalizer sections to cancel the effects of amplitude distortion. Cancellation of group delay distortion is predicated upon its being proportional to amplitude of the slope correction required. Thus, group delay correction is introduced in relation to the slope correction introduced to compensate for distortion introduced during normal multipath propagation conditions.

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