Virtual real-time clock based on time information from multiple communication systems
First Claim
1. A method for implementing a virtual real-time clock based on time information from a plurality of communication systems, comprising:
- receiving absolute time information from a first communication system;
receiving relative time information from a second communication system; and
providing an estimate of absolute time at a designated time instant based on the absolute time information from the first communication system and the relative time information from the second communication system.
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Accused Products
Abstract
Method and apparatus to implement a “virtual” real-time clock at a terminal based on time information from multiple communication systems. At least one system (e.g., GPS) provides “absolute” time information for the virtual real-time clock, and at least one other system (e.g., a cellular system) provides “relative” time information. The virtual real-time clock is “time-stamped” with absolute time as it becomes available from the first system. Relative time (which may be received from multiple asynchronous transmitters) is mapped to the timeline of the virtual real-time clock as it is received from the second system. Absolute time at any arbitrary time instant on the timeline may then be estimated based on the absolute time from the first system and the relative time from the second system. Absolute times from the first system for two or more time instants may also be used to calibrate the relative time from the second system.
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Citations
38 Claims
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1. A method for implementing a virtual real-time clock based on time information from a plurality of communication systems, comprising:
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receiving absolute time information from a first communication system;
receiving relative time information from a second communication system; and
providing an estimate of absolute time at a designated time instant based on the absolute time information from the first communication system and the relative time information from the second communication system. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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8. A method for providing an estimate of absolute time based on time information from a plurality of communication systems, comprising:
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obtaining absolute time from a first communication system for a first time instant;
receiving a first signaling message from a second communication system at a second time instant;
determining a time offset between the first and second time instants;
receiving a second signaling message from the second communication system at a third time instant;
determining an elapsed time between the second and third time instants;
determining a time difference between the third time instant and a fourth time instant; and
providing an estimate of absolute time at the fourth time instant based on the absolute time for the first time instant, the time offset, the elapsed time, and the time difference. - View Dependent Claims (9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19)
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20. A method for providing an estimate of absolute time based on time information from a plurality of communication systems, comprising:
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receiving absolute time information from a first communication system;
receiving relative time information from a first transmitter in a second communication system;
receiving relative time information from a second transmitter in the second communication system; and
providing an estimate of absolute time at a designated time instant based on the absolute time information from the first communication system and the relative time information from the first and second transmitters in the second communication system. - View Dependent Claims (21, 22)
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23. A method for providing an estimate of absolute time based on time information from a plurality of communication systems, comprising:
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obtaining absolute time from a first communication system for a first time instant;
receiving a first signaling message from a first transmitter in a second communication system at a second time instant;
determining a first time offset between the first and second time instants;
receiving a second signaling message from a second transmitter in the second communication system at a third time instant;
determining a second time offset between the first and third time instants; and
providing an estimate of absolute time at a designated time instant based at least in part on the absolute time for the first time instant and the second time offset. - View Dependent Claims (24, 25)
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26. A method for determining a position of a receiver unit in a wireless communication system, comprising:
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obtaining absolute time from a first communication system for a first time instant;
receiving relative time information from a second communication system;
estimating absolute time at a second time instant based on the absolute time for the first time instant and the relative time information from the second communication system; and
determining the position of the receiver unit based at least in part on the absolute time estimate for the second time instant. - View Dependent Claims (27, 28)
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29. A memory communicatively coupled to a digital signal processing device (DSPD) capable of interpreting digital information to:
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receive absolute time information from a first communication system;
receive relative time information from a second communication system; and
provide an estimate of absolute time at a designated time instant based on the absolute time information from the first communication system and the relative time information from the second communication system.
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30. A computer program product for providing an estimate of absolute time based on time information from a plurality of communication systems, comprising:
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code for receiving absolute time from a first communication system for a first time instant;
code for receiving relative time information from a second communication system;
code for providing an estimate of absolute time at a designated time instant based on the absolute time for the first time instant and the relative time information from the second communication system; and
a computer-usable medium for storing the codes.
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31. An apparatus for implementing a virtual real-time clock based on time information from a plurality of communication systems, comprising:
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means for receiving a representation of a timeline;
means for receiving absolute time information from a first communication system;
means for associating the absolute time information with the timeline;
means for receiving relative time information from a second communication system;
means for mapping the relative time information to the timeline; and
means for providing an estimate of absolute time at a designated time instant on the timeline based on the associated absolute time information and the mapped relative time information. - View Dependent Claims (32)
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33. A receiver unit in a wireless communication system, comprising:
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a first receiver operative to process signals from a first communication system to provide absolute time information;
a second receiver operative to process signals from a second communication system to provide relative time information; and
a processing unit operative to provide an estimate of absolute time at a designated time instant based on the absolute time information from the first communication system and the relative time information from the second communication system. - View Dependent Claims (34, 35, 36, 37)
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38. A receiver apparatus in a wireless communication system, comprising:
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means for processing signals from a first communication system to provide absolute time information;
means for processing signals from a second communication system to provide relative time information; and
means for providing an estimate of absolute time at a designated time instant based on the absolute time information from the first communication system and the relative time information from the second communication system.
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Specification