Patent · US Expired

Coherent phase shift keyed demodulator

US4871974A · kind A · utility

43Cited by
20References
22Claims
0Family size

Assignee

Inventors

Key dates

Filing dateDec 23, 1988
Grant dateOct 3, 1989
Priority date
Expiry dateDec 23, 2008

Classification

  • Technology area (CPC H)Electricity
  • CPC primaryH04L27/2275
  • WIPO fieldDigital communication
  • WIPO sectorElectrical engineering

Abstract

A demodulator mechanism which uses estimates of the in-phase and quadrature-phase components of differential phase modulated carrier signals for performing a coherent demodulation of these signals is described. The instantaneous estimates, obtained from an estimator circuit, are fed into a differential carrier recovery circuit, which provides for a feedback of ideal sine and cosine components, and combined with the instantaneous estimates for incrementally decreasing a phase error signal generated in a computational circuit. By thus incrementally decreasing the phase error signal, an ideal phase angle is eventually obtained, thereby providing for coherent demodulated output components of the input carrier signals.

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