Method and device for acquiring weak global navigation satellite system (GNSS) signals
US7522100B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jul 1, 2005 |
| Grant date | Apr 21, 2009 |
| Priority date | — |
| Expiry date | Oct 21, 2025 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01S19/37
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A Global Navigation Satellite System (GNSS) receiver and associated method capable of acquiring weak GNSS signals from a plurality of GNSS satellites produces a GNSS signal's code time, carrier frequency, and data bit transition parameters for subsequent signal tracking and position fixing. The GNSS receiver includes a baseband signal processor with special functionalities for acquiring weak signals. In a preferred embodiment, the time and frequency uncertainty space is reduced using available information and then special techniques are used to rapidly search the remaining uncertainty space. Successive reversal of short-length correlations within a data bit interval (a block) enables data bit transition detection and data bit sign correction prior to coherent integration. Fast Fourier Transform (FFT) is applied as a bank of bandpass filters to coherently accumulate blocks of short-length correlations over extended coherent integration intervals to boost the signal power while averaging noise out despite unknown data bit transitions.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.