초록 ▼

Methods and apparatuses for deriving an approximate Doppler for a satellite positioning system (SPS) receiver from an approximate location which is obtained from a cellular communication system information source. In one embodiment, an approximate location of the SPS receiver is derived from the inf

Methods and apparatuses for deriving an approximate Doppler for a satellite positioning system (SPS) receiver from an approximate location which is obtained from a cellular communication system information source. In one embodiment, an approximate location of the SPS receiver is derived from the information source and this approximation location is used to determine approximate Dopplers to a plurality of SPS satellites at a given time. The approximate Dopplers are then used to reduce processing time in either determining pseudoranges to the SPS satellites or acquiring signals from the SPS satellites. In another aspect of the invention, a reference signal is used to provide a local oscillator signal which is used to acquire SPS signals in an SPS receiver. This reference signal is extracted from a data signal modulated on a carrier frequency. The data signal on the carrier frequency is transmitted from, in one example, a wireless cell site which is communicating with the SPS receiver which has a cellular based communication receiver.

대표청구항 ▼

[What is claimed is:] [1.]determining an approximate location of said SPS receiver from a cell based information source, said approximate location being determined by at least one of a location of a cellular service area which includes a cell site or a location of said cell site;determining an appro

[What is claimed is:] [1.]determining an approximate location of said SPS receiver from a cell based information source, said approximate location being determined by at least one of a location of a cellular service area which includes a cell site or a location of said cell site;determining an approximate Doppler for at least one SPS satellite relative to said SPS receiver, said approximate Doppler being based on said approximate location;using said approximate Doppler in said SPS receiver to reduce processing time in one of either determining at least one pseudorange to said at least one SPS satellite or acquiring signals from said at least one SPS satellite and wherein said at least one SPS satellite transmits ephemeris data for said at least one SPS satellite and wherein said SPS receiver and said cell based communication receiver do not use a common communication link.