Patent · US Expired

Digital signal processing method and apparatus

US4306249A · kind A · utility

23Cited by
2References
24Claims
0Family size

Assignee

Inventor

Key dates

Filing dateDec 18, 1979
Grant dateDec 15, 1981
Priority date
Expiry dateDec 18, 1999

Classification

  • Technology area (CPC H)Electricity
  • CPC primaryH04N19/59
  • WIPO fieldAudio-visual technology
  • WIPO sectorElectrical engineering

Abstract

Encoded digital television signals having a defined bandwidth are transmitted at reduced bandwidth by regularly omitting (18) one in every n of the signal samples, where n is greater than two and is preferably three or four. At a receiver the omitted samples are regenerated by estimating (26) their values from the samples of the reduced-rate transmitted signal by making use of frequency components outside the normal defined bandwidth of the original signal. The estimation can be achieved by a symmetrical digital transversal filter of which one in every n coefficients is zero, the amplitude/frequency characteristics of the filter being unity throughout the defined bandwidth of the TV signal and antisymmetric about half the mean lower sample rate.

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