Patent · US Expired

Speech coding transmission equipment

US4890325A · kind A · utility

22Cited by
3References
6Claims
0Family size

Assignee

Inventors

Key dates

Filing dateFeb 18, 1988
Grant dateDec 26, 1989
Priority date
Expiry dateFeb 18, 2008

Classification

  • Technology area (CPC H)Electricity
  • CPC primaryH04B1/662
  • WIPO fieldComputer technology
  • WIPO sectorElectrical engineering

Abstract

Speech is data-compressed and coded for transmission using TDHC (Time Domain Harmonic Compression) for the voiced signal, and decimated sampling for the unvoiced signal. Features include voiced/unvoiced detection, pitch period detection, border detection, coding by ADPCM, and optimum quantization coding. Reception involves decoding and data-reconstruction.

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