Image Number 6 for United States Patent #6856282.
In general, the invention is directed to techniques for directly acquiring P-codes without first acquiring C/A-codes. For example, in one embodiment, a system comprises an assist server to track a P-code signal from a Global Positioning System (GPS) satellite and generate acquisition assistance information from the signal. The system further comprises a mobile unit to receive the acquisition assistance data from the assist server, and to acquire the P-code signal from the satellite based on the acquisition assistance data. The acquisition assistance data may include time-of-week data indicating an initial time offset into a P-code pseudorandom code sequence for the satellite. The mobile unit may include a reference generator to locally generate a reference pseudorandom code sequence based on the time-of-week data.