GPS receiver utilizing a communication link
First Claim
1. A method for providing a local oscillator signal in a mobile satellite positioning system (SPS) receiver, said method comprising:
- receiving a signal having a carrier frequency and a data signal modulated on said carrier frequency;
extracting a reference signal from said data signal modulated on said carrier frequency;
using said reference signal to provide a local oscillator signal to acquire SPS signals, wherein said signal is distinct from said SPS signals.
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Abstract
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.
333 Citations
17 Claims
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1. A method for providing a local oscillator signal in a mobile satellite positioning system (SPS) receiver, said method comprising:
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receiving a signal having a carrier frequency and a data signal modulated on said carrier frequency;
extracting a reference signal from said data signal modulated on said carrier frequency;
using said reference signal to provide a local oscillator signal to acquire SPS signals, wherein said signal is distinct from said SPS signals. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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9. A method for providing a satellite information to a satellite positioning system (SPS) receiver, said method comprising:
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determining an approximate location of an SPS receiver from a cell based information source, said approximate location being based on at least one of a location of a cellular service area which includes a wireless cell site and a location of said wireless cell site, and determining a plurality of satellite ephemeris data for a corresponding plurality of satellites, which are in view of said approximate location;
transmitting said plurality of satellite ephemeris data from a wireless cellular transmitter of said wireless cell site to an SPS receiver in a cell serviced by said wireless cell site. - View Dependent Claims (10, 11, 12, 13, 14)
receiving a plurality of pseudorange data from said SPS receiver, said plurality of pseudorange data being determined by said SPS receiver.
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12. A method as in claim 11 further comprising:
computing a position information of said SPS receiver by using SPS signals from a source of SPS signals and said plurality of pseudoranges.
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13. A method as in claim 12 wherein said position information is computed by also using said approximate location.
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14. A method as in claim 12 further comprising:
transmitting a signal having a carrier frequency and a data signal modulated on said carrier frequency, said SPS receiver using one of said carrier frequency and said data signal to provide a local oscillator signal which is used to acquire SPS signals.
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15. A combined mobile satellite positioning system (SPS) receiver and a communication receiver, said SPS receiver and communication receiver comprising:
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a first antenna which receives a communication signal having a data signal modulated on a carrier frequency;
a data signal acquisition and tracking circuit coupled to said first antenna, said acquisition and tracking circuit producing a reference signal from the data signal;
a frequency synthesizer coupled to said acquisition and tracking circuit to receive said reference signal, said frequency synthesizer providing a local oscillator signal to acquire SPS signals in said SPS receiver. - View Dependent Claims (16, 17)
a voltage controlled oscillator (VCO) in said acquisition and tracking circuit, said VCO providing said reference signal; and
whereinsaid data signal comprises a pseudorandom sequence.
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17. A combined SPS receiver and communication receiver as in claim 15 wherein said reference signal is generated by locking to said data signal.
Specification