Infrastructure-aiding for satellite navigation receiver and method
First Claim
1. A satellite-navigation system, comprising,a first satellite-navigation receiver that provides for a first position solution;
- a first wireless communications device collocated with the first satellite-navigation receiver and connected to share at least one of time and frequency measurements with the first satellite-navigation receiver;
a second satellite-navigation receiver for providing an accurate time and frequency estimate;
a second wireless communications device collocated with the second satellite-navigation receiver and able to make radio contact with the first wireless communications device; and
a webserver for post-processing of said first position solution with said accurate time and frequency estimate and for extracting a more accurate second position solution for the first satellite-navigation receiver, and connected by a data network to the second satellite-navigation receiver and second wireless communications device.
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Accused Products
Abstract
A navigation system comprises a cell-phone, a base cellular telephone site, and a webserver. Each is paired with a GPS receiver. The GPS receiver associated with the cell-phone is aided with information received from the cell-site and webserver that help reduce satellite search uncertainty. Time difference and/or frequency difference measurements are taken with data collected from what the cell-phone and its GPS receiver assume to be accurate time and frequency. Correction information is used in post-processing of the velocity solutions computed by the cell-phone to arrive at more precise determinations for the system.
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Citations
16 Claims
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1. A satellite-navigation system, comprising,
a first satellite-navigation receiver that provides for a first position solution; -
a first wireless communications device collocated with the first satellite-navigation receiver and connected to share at least one of time and frequency measurements with the first satellite-navigation receiver;
a second satellite-navigation receiver for providing an accurate time and frequency estimate;
a second wireless communications device collocated with the second satellite-navigation receiver and able to make radio contact with the first wireless communications device; and
a webserver for post-processing of said first position solution with said accurate time and frequency estimate and for extracting a more accurate second position solution for the first satellite-navigation receiver, and connected by a data network to the second satellite-navigation receiver and second wireless communications device. - View Dependent Claims (2, 3, 4, 5, 11, 12, 13, 14)
the webserver provides information to the first satellite-navigation receiver that reduces at least one of local-oscillator frequency uncertainty and time uncertainty, and provides for improved satellite search times and sensitivity.
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4. The system of claim 3, wherein:
the webserver computes time-difference information by comparing time measurements between the first and second satellite-navigation receiver as communicated over a radio contact and said data network.
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5. The system of claim 3, wherein:
the webserver computes frequency-difference information by comparing carrier frequency measurements between the first and second wireless communication devices, and such measurements are communicated over a radio contact and said data network.
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11. The system of claim 3, wherein:
the webserver collects temperature measurement (tempMeas) observables and stores them in a database from which it later builds a temperature-frequency model used to improve receiver sensitivity and acquisition performance in a software-compensated-crystal-oscillator (SCXO).
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12. The system of claim 1, wherein:
a minimum of one GPS satellite and three cell site base stations are used in a dual mode system configuration.
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13. The system of claim 3, wherein:
the webserver includes a global positioning system (GPS) digital signal processor (DSP) application specific integrated circuit (ASIC) that integrates time-difference, frequency-difference, and temperature-measurement infrastructure-information for improved satellite acquisition and receiver sensitivity.
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14. The system of claim 1, wherein:
position-solution calculations are distributed amongst the webserver and the wireless communications devices.
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6. A satellite-navigation system, comprising,
a first satellite-navigation receiver that provides for a user position solution; -
a cell-phone collocated with the first satellite-navigation receiver and connected to share time and frequency measurements with the first satellite-navigation receiver;
a second satellite-navigation receiver for providing an accurate time and frequency estimate;
a base cellular telephone site collocated with the second satellite-navigation receiver and able to make radio contact with the cell-phone; and
a webserver for post-processing of said user position solution with said accurate time and frequency estimate and for extracting a more accurate second position solution for the first satellite-navigation receiver, and connected by a data network to the second satellite-navigation receiver and base cellular telephone site. - View Dependent Claims (7, 8, 9, 10)
the second satellite-navigation receiver and base cellular telephone site are at a fixed location and a local differential correction measurement is obtained and communicated to the webserver for providing increased accuracy position solutions for the first satellite-navigation receiver.
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8. The system of claim 6, wherein:
the webserver provides information to the first satellite-navigation receiver that reduces at least one of local-oscillator frequency uncertainty and time uncertainty, and provides for improved satellite search times and sensitivity.
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9. The system of claim 8, wherein:
the webserver computes time-difference information by comparing time measurements between the first and second satellite-navigation receiver as communicated over a cellular radio contact and said data network.
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10. The system of claim 8, wherein:
the webserver computes frequency-difference information by comparing carrier frequency measurements between cellular telephone devices, and such measurements are communicated over a cellular radio contact and said data network.
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15. A satellite-navigation system, comprising,
a first satellite-navigation receiver that provides for a first position solution; -
a first cell-phone collocated with the first satellite-navigation receiver and connected to make and share at least one of time and frequency measurements made with the aid of the first satellite-navigation receiver;
a second satellite-navigation receiver for providing an accurate time and frequency estimate;
a second cell-phone collocated with the second satellite-navigation receiver and able to make a telephone connection with the first cell-phone through a cellular base station located in the area; and
a webserver with telephone access to each of the cell-phones via the cellular base station, and for post-processing of said first position solution with said accurate time and frequency estimate and for extracting a more accurate second position solution for the first satellite-navigation receiver, and connected by a data network to the second satellite-navigation receiver and second cell-phone;
wherein, the first satellite-navigation receiver and first cell-phone are permanently parked at a stationary location and are continually accessible to the webserver.
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16. A navigation system comprises a cell-phone, a base cellular telephone site, and a webserver, wherein each are paired with a global positioning system (GPS) receiver;
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wherein, a GPS receiver associated with the cell-phone is aided with information received from the cell-site and webserver that help reduce satellite search uncertainty with time-difference and/or frequency-difference measurements taken with data collected using local cell-phone and GPS receiver time and frequency; and
wherein, correction information is used in post-processing of any velocity solutions computed by the cell-phone.
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Specification