Method and apparatus for accelerating code correlation searches in initial acquisition and doppler and code phase in re-acquisition of GPS satellite signals
Number of patents in Portfolio can not be more than 2000
United States of America Patent
Stats
-
May 30, 1995
Grant Date -
N/A
app pub date -
Apr 9, 1993
filing date -
Apr 9, 1993
priority date (Note) -
In Force
status (Latency Note)
Importance
Abstract
An embodiment of the present invention is a GPS receiver comprising a GPS downconverter, a fast acquisition unit, a GPS digital signal processor (DSP), a static random access memory (SRAM) and a temperature compensated crystal oscillator (TCXO). The fast acquisition unit samples intermediate frequency signals from the GPS downconverter at 5.17 MHz and writes the samples to the SRAM memory. The memory then supplies the samples back out at a rate of 10.34 MHz. The GPS DSP is such that PRN code and code phase searches are conducted at two times the real-time transmission rate of a GPS satellite. Once a code lock is obtained, Doppler, code, code phase and ephemeris data are stored by a GPS processor. If lock is lost, past code phase and Doppler are projected forward in time using ephemeris and other relevant GPS satellite knowledge to constrain a new search to re-establish lock.
First Claim
Family
International Classification(s)
- [Classification Symbol]
- [Patents Count]
Cited Art Landscape
Patent Citation Ranking
Advertisement
Advertisement
Advertisement
Recipient Email Address
Recipient Email Address
Comment
Recipient Email Address
Add to Portfolio(s)
To add this patent to one, or more, of your portfolios, simply click the add button.
This Patent is in these Portfolios:
Add to additional portfolios:
Last Refreshed On:
Changes done successfully