Method of deriving phase of pseudo-random code signal in global positioning system receiver
US5081462A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 16, 1991 |
| Grant date | Jan 14, 1992 |
| Priority date | — |
| Expiry date | May 16, 2011 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01S19/30
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A method, for use in a receiver for the NAVSTAR global positioning system (GPS), of deriving successive values of phase of a received pseudo-random code signal following a momentary interruption of satellite signal reception, with the effects of signal noise eliminated by averaging processing, by first setting a replica pseudo-random code signal to an initial phase value which provides high correlation with the received code signal, and thereafter periodically executing phase derivation operations to obtain the phase of the received code signal, by obtaining the phase difference between the received and replica code signals, obtaining the average value of all of such phase differences obtained up to that point since the initial phase derivation operation, and adding that average value to the sum of a phase value obtained in the first phase derivation operation and a total estimated amount of change of phase of the received code since that first operation. The estimated phase change is obtained based on a corresponding amount of frequency change that has occurred in the carrier of the received signal.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.