System and method for fast code phase and carrier frequency acquisition in GPS receiver
US7505508B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Sep 3, 2007 |
| Grant date | Mar 17, 2009 |
| Priority date | — |
| Expiry date | Sep 3, 2027 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04B2201/70715
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A GPS receiver acquires carrier frequency and Gold code phase using short segments of a received GPS signal. In one embodiment, a 1-ms segment of the GPS signal is transformed to the frequency domain. This is multiplied by a frequency representation of the Gold code. The resulting product is converted to the time domain, and a peak is detected. The location of the peak corresponds to the code phase. If no peak is located, the carrier frequency is changed. Full- and half-bin steps in carrier frequency are considered. Processing gain is achieved by using longer segments of the input signal, for example 4 or 16 ms and integrating 1-ms segments. Considerations are provided for compensating for the effects of a transition, should it occur in the short segment of the GPS signal being processed. Integrations can be performed using non-coherent and coherent techniques. Adjustments are made for non-integral millisecond segment lengths.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.