Patent · US Expired

Obtaining pilot phase offset time delay parameter for a wireless terminal of an integrated wireless-global positioning system

US6636744B1 · kind B1 · utility

36Cited by
8References
18Claims
0Family size

Assignee

Inventor

Key dates

Filing dateApr 20, 2000
Grant dateOct 21, 2003
Priority date
Expiry dateApr 20, 2020

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG01S19/46
  • WIPO fieldMeasurement
  • WIPO sectorInstruments

Abstract

An integrated wireless-global positioning system determines the location of a wireless terminal from satellite measurements and wireless network measurements. The accuracy of the location identified is dependent upon the quality of the measurement from the wireless network which, unfortunately, can contain measurement errors such as biases. Biases are caused by time delays which occur during the processing and transmission of signals. The time delays vary for each sector/base station and for each type of wireless terminal model being used. Calibration of these biases is important for the success of the integrated wireless global positioning system. For a small network system which has only a handful of base stations/wireless terminals, a specific system to calibrate the time delays for each base station and/or wireless terminal can be set up. The approach is, however, costly, time consuming, and subject to many errors. It is not feasible for a large scale, commercial system where hundreds of base stations and dozens of different types of wireless terminals are involved. This invention is a method of using an integrated wireless global positioning system to obtain pilot phase offset…

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