Method and apparatus for acquiring satellite positioning system signals
First Claim
1. A method for reducing search time to acquire satellite positioning system (SPS) signals in a satellite positioning system (SPS) receiver, said method comprising:
- determining a first pseudorange to a first SPS satellite;
determining an approximate location of said SPS receiver;
determining an estimated pseudorange for a second pseudorange to a second SPS satellite, said estimated pseudorange being determined from said approximate location and said first pseudorange;
searching for time of arrival of SPS signals from said second SPS satellite in a range determined by said estimated pseudorange.
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Accused Products
Abstract
A method and an apparatus which acquire satellite positioning system (SPS) signals in an SPS receiver. Information on time of day, approximate receiver location, and satellite positions are used to reduce the time to search and acquire signals from one or more SPS satellites. In an example of a method of the invention, a first pseudorange to a first SPS satellite is determined, and an approximate location of the SPS receiver is determined. An estimated pseudorange for a second pseudorange to a second SPS satellite is determined from the approximate location and a satellite position of the second SPS satellite. The SPS receiver then searches for SPS signals from the second SPS satellite in a range determined by the estimated pseudorange. Typically, this method reduces the search time to initially acquire SPS signals from the second SPS satellite, and the estimated pseudorange is not based on a previously determined pseudorange for said second SPS satellite. In a particular example of the invention, the approximate location is determined from a cell based information source which correlates an identification of each of various wireless cell sites with an approximate location for objects within a cell of a wireless cell based communication system, such as a cellular (or cell based) telephone system. In other examples of the invention, relatively precise time of day information may be used with information indicating satellite positions and information indicating the approximate location to determine an estimated pseudorange for a first SPS satellite to be acquired.
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Citations
114 Claims
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1. A method for reducing search time to acquire satellite positioning system (SPS) signals in a satellite positioning system (SPS) receiver, said method comprising:
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determining a first pseudorange to a first SPS satellite; determining an approximate location of said SPS receiver; determining an estimated pseudorange for a second pseudorange to a second SPS satellite, said estimated pseudorange being determined from said approximate location and said first pseudorange; searching for time of arrival of SPS signals from said second SPS satellite in a range determined by said estimated pseudorange. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48)
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14. A method for initially acquiring satellite positioning system (SPS) signals in a SPS receiver, said method comprising:
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determining a first pseudorange to a first SPS satellite; determining an approximate location of said SPS receiver; determining an estimated pseudorange for a second pseudorange to a second SPS satellite, said estimated pseudorange being determined from said approximate location and said first pseudorange; searching for time of arrival of SPS signals from said second SPS satellite in a range determined by said estimated pseudorange. - View Dependent Claims (15, 16, 17, 18, 19, 20, 21, 22)
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23. A satellite positioning system (SPS) receiver comprising:
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an SPS antenna which is configured to receive SPS signals; a processor coupled to said SPS antenna, said processor determining a first pseudorange to a first SPS satellite and searching for time of arrival of SPS signals from a second SPS satellite in a range determined by an estimated pseudorange to said second SPS satellite, said estimated pseudorange being determined from an approximate location of said SPS receiver and from said first pseudorange. - View Dependent Claims (24, 25, 26, 27, 28, 29)
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30. A digital processing system comprising:
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a communication interface; a storage device; a processor coupled to said storage device and to said communication interface, said processor determining an approximate location of a mobile satellite positioning system (SPS) receiver which is capable of communication with said digital processing system through said communication interface and wherein said processor determines an estimated pseudorange for a first pseudorange to a first SPS satellite, said estimated pseudorange being determined from said approximate location and a satellite position of said first SPS satellite and wherein said estimated pseudorange is transmitted through said communication interface to said mobile SPS receiver. - View Dependent Claims (31, 32, 33, 34, 35)
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36. A computer readable medium containing executable computer program instructions which, when executed by a data processing system, cause said data processing system to perform a method comprising:
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determining an approximate location of a mobile satellite positioning system (SPS) receiver; determining an estimated pseudorange for a first pseudorange to a first SPS satellite, said estimated pseudorange being determined from said approximate location and a satellite position of said first SPS satellite; transmitting said estimated pseudorange to said mobile SPS receiver. - View Dependent Claims (37)
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49. A method for reducing search time to acquire satellite positioning system (SPS) signals in a satellite positioning system (SPS) receiver, said method comprising:
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determining a time of day at said SPS receiver to an accuracy of better than a framing period of said SPS signals; determining an approximate location of said SPS receiver; determining an estimated pseudorange for at least one SPS satellite, said estimated pseudorange being determined from said approximate location and from a satellite position data and from said time of day; searching for time of arrival of SPS signals from said SPS satellite in a range determined by said estimated pseudorange. - View Dependent Claims (50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 78, 79, 80, 81, 82, 83)
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62. A method for initially acquiring satellite positioning system (SPS) signals in a SPS receiver, said method comprising:
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determining a time of day at said SPS receiver to an accuracy of better than a framing period of said SPS signals; determining an approximate location of said SPS receiver; determining an estimated pseudorange for at least one SPS satellite, said estimated pseudorange being determined from said approximate location and from a satellite position data and from said time of day; searching for time of arrival of SPS signals from said SPS satellite in a range determined by said estimated pseudorange. - View Dependent Claims (63, 64, 65, 66, 67, 68, 69, 70)
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71. A satellite positioning system (SPS) receiver comprising:
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an SPS antenna which is configured to receive SPS signals; a processor coupled to said SPS antenna, said processor determining a time of day at said SPS receiver to an accuracy of better than a framing period of said SPS signals and searching for a time of arrival of SPS signals from an SPS satellite in a range determined by an estimated pseudorange to said SPS satellite, said estimated pseudorange being determined from an approximate location of said SPS receiver and from a satellite position data and from said time of day. - View Dependent Claims (72, 73, 74, 75, 76, 77)
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84. A method for reducing search time to acquire satellite positioning system (SPS) signals in a satellite positioning system (SPS) receiver, said method comprising:
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determining a time of day at said SPS receiver; obtaining a set of mathematical descriptions of estimated ranges versus time, said estimated ranges being from said SPS receiver to said SPS satellites viewable by said SPS receiver; determining an estimated pseudorange for at least one SPS satellite, said estimated pseudorange being determined from said time of day and from said set of mathematical descriptions; searching for time of arrival of SPS signals from said SPS satellite in a range determined by said estimated pseudorange. - View Dependent Claims (85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 110, 111, 112, 113, 114)
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97. A satellite positioning system (SPS) receiver comprising:
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an SPS antenna which is configured to receive SPS signals; a processor coupled to said SPS antenna, said processor determining a time of day at said SPS receiver and searching for time of arrival of SPS signals from an SPS satellite in a range determined by an estimated pseudorange to said SPS satellite, said estimated pseudorange being determined from said time of day and from a set of mathematical descriptions of estimated ranges versus time, said estimated ranges being from said SPS receiver to said SPS satellites viewable by said SPS receiver. - View Dependent Claims (98, 99, 100, 101, 102)
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103. A digital processing system comprising:
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a communication interface; a storage device; a processor coupled to said storage device and to said communication interface, said processor determining an approximate location of a mobile satellite positioning system (SPS) receiver which is capable of communication with said digital processing system through said communication interface and wherein said processor determines a set of mathematical descriptions of estimated ranges versus time, said estimated ranges being from said SPS receiver to said SPS satellites viewable by said SPS receiver, said set of mathematical expressions being determined from said approximate location and wherein said set of mathematical expressions is transmitted through said communication interface to said mobile SPS receiver. - View Dependent Claims (104, 105, 106, 107, 108)
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109. A computer readable medium containing executable computer program instructions which, when executed by a data processing system, cause said data processing system to perform a method comprising:
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determining an approximate location of a mobile satellite positioning system (SPS) receiver; determining a set of mathematical descriptions of estimated ranges versus time, said estimated ranges being from said SPS receiver to SPS satellites viewable by said SPS receiver, said set of mathematical descriptions being determined from said approximate location; transmitting said set of mathematical descriptions to said mobile SPS receiver.
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Specification