Dual Frequency global positioning system
US5736961A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 6, 1995 |
| Grant date | Apr 7, 1998 |
| Priority date | — |
| Expiry date | Oct 6, 2015 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01S19/29
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A global position system receiver recovers the L1 and L2 carriers, the C/A-code measurements and the L1 and L2 P-code measurements by (a) producing an estimate of the L1 carrier phase angle and synchronizing a locally generated C/A-code with the L1 signal using an L1 delay lock loop and controlling, based on the locally generated C/A code, an L1 P-code generator that produces a synchronized version of the P-code; (b) initializing an L2 P-code generator based on the phase of the P-code generated by the L1 P-code generator; (c) determining, for the L2 signal, an estimate of signal power that is adjusted to compensate for noise; (d) determining an L2 carrier phase angle; (e) tracking the L2 P-code by adjusting an L2 P-code generator until the estimate of signal power is maximized. The GPS receiver also resolves a 1/2 cycle ambiguity in tracking the L2 P-code by comparing demodulated L1 P-code bits and L2 P-code bits. If the bits do not match in the majority of instances, the receiver determines that it is tracking the L2 P-code with 1/2 cycle error and adjusts its estimate of the P-code phase accordingly. The receiver may determine the reliability of the independently tracked L2 signa…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.