Patent · US Expired

Method and apparatus for acquiring a ranging signal of a positioning system

US7120191B2 · kind B2 · utility

3Cited by
5References
10Claims
0Family size

Assignee

Inventor

Key dates

Filing dateDec 12, 2001
Grant dateOct 10, 2006
Priority date—
Expiry dateDec 11, 2023

Classification

  • Technology area (CPC H)Electricity
  • CPC primaryH04L2027/0065
  • WIPO fieldMeasurement
  • WIPO sectorInstruments

Abstract

A method and corresponding apparatus for accurately determining the offset of the carrier frequency of a received signal from a nominal frequency (the offset due to for example Doppler shifting), such as is done in a ranging receiver when acquiring or tracking a signal transmitted by a beacon (such as a satellite) of a positioning system. The method amplifies a conventional correlation by performing a special noncoherent integration of the real and imaginary components of the output of a conventional (coherent) correlation calculation, resulting in a complex phasor having a phase that bears information about the offset of the carrier frequency from the nominal carrier frequency.

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