Method and apparatus for determining absolute time-of-day in a mobile-assisted satellite positioning system
First Claim
1. A method of determining time-of-day in a mobile receiver, comprising:
- receiving at the mobile station, acquisition assistance data from a server, said acquisition assistance data comprising expected pseudoranges to a plurality of satellites, said expected pseudoranges based on an initial position of said mobile receiver and an initial time-of-day;
obtaining expected line-of-sight data to said plurality of satellites;
measuring pseudoranges from said mobile receiver to said plurality of satellites;
computing update data for said initial time-of-day using a mathematical model relating said pseudoranges, said expected pseudoranges, and said expected line-of-sight data;
updating said initial time-of-day using said update data to compute a time-tag; and
transmitting said pseudoranges and said time-tag to a server in wireless communication with said mobile receiver.
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0 Petitions
Accused Products
Abstract
A method and apparatus for determining time-of-day in a mobile receiver is described. In one example, expected pseudoranges to a plurality of satellites are obtained. The expected pseudoranges are based on an initial position of the mobile receiver and an initial time-of-day. Expected line-of-sight data to said plurality of satellites is also obtained. Pseudoranges from said mobile receiver to said plurality of satellites are measured. Update data for the initial time-of-day is computed using a mathematical model relating the pseudoranges, the expected pseudoranges, and the expected line-of-sight data. The expected pseudoranges and the expected line-of-sight data may be obtained from acquisition assistance data transmitted to the mobile receiver by a server. Alternatively, the expected pseudoranges may be obtained from acquisition assistance data, and the expected line-of-sight data may be computed by the mobile receiver using stored satellite trajectory data, such as almanac data.
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Citations
49 Claims
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1. A method of determining time-of-day in a mobile receiver, comprising:
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receiving at the mobile station, acquisition assistance data from a server, said acquisition assistance data comprising expected pseudoranges to a plurality of satellites, said expected pseudoranges based on an initial position of said mobile receiver and an initial time-of-day; obtaining expected line-of-sight data to said plurality of satellites; measuring pseudoranges from said mobile receiver to said plurality of satellites; computing update data for said initial time-of-day using a mathematical model relating said pseudoranges, said expected pseudoranges, and said expected line-of-sight data; updating said initial time-of-day using said update data to compute a time-tag; and transmitting said pseudoranges and said time-tag to a server in wireless communication with said mobile receiver. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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11. Apparatus for determining time-of-day in a mobile receiver, comprising:
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a wireless transceiver for obtaining acquisition assistance data from a server, said acquisition assistance data comprising expected pseudoranges to a plurality of satellites based on an initial position of said mobile receiver and an initial time-of-day; a satellite signal receiver for measuring pseudoranges from said mobile receiver to said plurality of satellites; a processor for obtaining expected line-of-sight data to said plurality of satellites and for computing update data for said initial time-of-day using a mathematical model relating said pseudoranges, said expected pseudoranges, and said expected line-of-sight data; and a memory for storing almanac data associated with a constellation having said plurality of satellites; wherein said satellite signal receiver is further configured to measure pseudorange rates; and wherein said processor is further configured to compute an approximate position of said mobile receiver using said pseudorange rates and said almanac data and to obtain said expected line-of-sight data in response to said approximate position and said almanac data. - View Dependent Claims (12, 13, 14, 15, 16, 17, 18, 19, 20, 21)
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22. A method of determining time-of-day in a mobile receiver, comprising:
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receiving at the mobile station, acquisition assistance data from a server, said acquisition assistance data comprising expected pseudoranges to a plurality of satellites, said expected pseudoranges based on an initial position of said mobile receiver and an initial time-of-day; obtaining expected line-of-sight data to said plurality of satellites; measuring pseudoranges from said mobile receiver to said plurality of satellites; computing update data for said initial time-of-day using a mathematical model relating said pseudoranges, said expected pseudoranges, and said expected line-of-sight data; measuring pseudorange rates at said mobile receiver; obtaining almanac data; and computing an approximate position of said mobile receiver using said pseudorange rates and said almanac data; wherein said expected line-of-sight data is obtained in response to said approximate position and said almanac data. - View Dependent Claims (23, 24, 25, 26, 27, 28, 29, 30, 31)
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32. A method of determining time-of-day in a mobile receiver, comprising:
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receiving at the mobile station, acquisition assistance data from a server, said acquisition assistance data comprising expected pseudoranges to a plurality of satellites, said expected pseudoranges based on an initial position of said mobile receiver and an initial time-of-day; obtaining expected line-of-sight data to said plurality of satellites; measuring pseudoranges from said mobile receiver to said plurality of satellites; computing update data for said initial time-of-day using a mathematical model relating said pseudoranges, said expected pseudoranges, and said expected line-of-sight data; obtaining almanac data; obtaining an estimated position of said mobile receiver; and computing an approximate position of said mobile receiver using said almanac data and said estimated position; wherein said expected line-of-sight data is obtained in response to said approximate position and said almanac data. - View Dependent Claims (33, 34, 35, 36, 37, 38, 39, 40)
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41. Apparatus for determining time-of-day in a mobile receiver, comprising:
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a wireless transceiver for obtaining acquisition assistance data from a server, said acquisition assistance data comprising expected pseudoranges to a plurality of satellites based on an initial position of said mobile receiver and an initial time-of-day; a satellite signal receiver for measuring pseudoranges from said mobile receiver to said plurality of satellites; a processor for obtaining expected line-of-sight data to said plurality of satellites and for computing update data for said initial time-of-day using a mathematical model relating said pseudoranges, said expected pseudoranges, and said expected line-of-sight data; and a memory for storing almanac data associated with a constellation having said plurality of satellites; wherein said processor is further configured to compute an approximate position of said mobile receiver using an estimated position of said mobile receiver and said almanac data and to obtain said expected line-of-sight data in response to said approximate position and said almanac data. - View Dependent Claims (42, 43, 44, 45, 46, 47, 48, 49)
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Specification