Method, apparatus and system for synchronizing a cellular communication system to GPS time
View Patent ↗A ranging receiver ( 10 ) including a cellular module ( 11 ), for providing time according to a positioning system to enable synchronizing a wireless system to the positioning system. The ranging receiver ( 10 ) includes both the cellular module ( 11 ) and a main module ( 12 ) that provides ranging receiver functionality. When the cellular module ( 11 ) receives a time-stamped frame from the wireless system, it sends a trigger signal over a special hardware path to the main module ( 12 ), which then relates the time of trigger receipt to time according to the positioning system by calculating a position-velocity-time (PVT) solution, using a local clock ( 18 ) to get the difference in time between receipt of the trigger and the instant to which the PVT solution applies, and then communicates to the cellular module ( 11 ) when it received the trigger, according to positioning system time.
1. An apparatus ( 10 ), comprising:
a) a cellular module ( 11 ), responsive to a portion of a downlink frame signal conveying a cellular frame provided by a cellular communication system; and
b) a main module ( 12 ), responsive to ranging signals from beacons ( 27 ) of a positioning system in which time is kept according to a predetermined time reference;
the apparatus ( 10 ) characterized in that:
the cellular module ( 11 ) provides a trigger signal indicating the arrival of the portion of the downlink frame signal, and is further responsive to a signal indicating information for relating the instant at which the trigger signal is provided to a time value according to the predetermined time reference;
the apparatus ( 10 ) relates the instant at which the trigger signal is provided by the cellular module ( 11 ) to a time value according to the predetermined time reference; and
the main module ( 12 ) uses the time value for synchronizing into ranging signals from beacons ( 27 ) of the positioning system;
wherein the trigger signal is provided over a connection ( 29 ) between the cellular module ( 11 ) and the main module ( 12 ) so constructed that any delay between sending and receiving the trigger signal is either negligible or can be determined.
2. The apparatus of claim 1 , further characterized in that the cellular module ( 11 ) provides to a base station of the cellular communication system the information for relating to a time value, according to the predetermined time reference, the instant at which the trigger signal is provided by the cellular module ( 11 ) to the main module ( 12 ).
3. The apparatus of claim 2 , further characterized in that the main module ( 12 ) provides a position for the instant when the trigger signal is received by the main module ( 12 ), and the cellular module ( 11 ) is responsive to the position, and provides the position to the base station.
4. A system, comprising an apparatus according to claim 2 , and further comprising the beacons ( 27 ) of the positioning system that provide the ranging signals and also comprising the base station receiving the information for relating to a time value, according to the predetermined time reference, the instant at which the trigger signal is provided.
5. A system, comprising an apparatus according to claim 1 , and further comprising a cellular base station ( 24 ), for providing the cellular frame.
6. A system, comprising an apparatus according to claim 1 , and further comprising the beacons ( 27 ) of the positioning system that provide the ranging signals.
7. A method for having a ranging receiver ( 10 ), operative in communication with a positioning system and also operative in communication with a cellular communication system, provide information to a base station of the cellular communication system of use in enabling the base station to synchronize to time according to the positioning system, the ranging receiver ( 10 ) including a cellular module ( 12 ) adapted for communication with the cellular communication system and also including a main module ( 12 ) adapted for communication with the positioning system, the method characterized by:
a) a step ( 32 ) in which the cellular module ( 11 ) detects a portion of a downlink frame signal and provides a trigger signal to the main module ( 12 ) via a connection so constructed that any delay between applying a signal and receiving the signal is either negligible or can be determined;
b) a step ( 40 ) in which the cellular module ( 11 ) receives a signal indicating information for relating the instant at which the trigger signal is provided to a time value according to the predetermined time reference; and
c) a step ( 40 ) in which the apparatus ( 10 ) relates the instant at which the trigger signal is provided by the cellular module ( 11 ) to a time value according to the predetermined time reference.
8. The method of claim 7 , further characterized by a step ( 40 ) in which the cellular module ( 11 ) provides to the base station the information for relating to a time value according to the positioning system, the instant at which the trigger signal is provided.
9. The method of claim 8 , further characterized by a step ( 38 40 ) in which the main module ( 12 ) also provides a position for the instant when the trigger signal was received by the main module ( 12 ), and the cellular module ( 11 ) is responsive to the position, and provides the position to the base station.
10. An apparatus ( 10 ), comprising:
a) a cellular module ( 11 ), responsive to a portion of a downlink frame signal conveying a cellular frame provided by a cellular communication system; and
b) a main module ( 12 ), responsive to ranging signals from beacons ( 27 ) of a positioning system in which time is kept according to a predetermined time reference;
the apparatus ( 10 ) characterized in that:
the cellular module ( 11 ) provides a trigger signal indicating the arrival of the portion of the downlink frame signal; and
the apparatus ( 10 ) relates the instant at which the trigger signal is provided by the cellular module ( 11 ) to a time value according to the predetermined time reference;
wherein the cellular module ( 11 ) provides to the cellular communication system information about the relationship of the downlink frame signal to a time value according to the predetermined time reference.
11. The apparatus of claim 10 , further characterized in that the cellular module ( 11 ) provides to a base station of the cellular communication system the information for relating to a time value, according to the predetermined time reference, the instant at which the trigger signal is provided by the cellular module ( 11 ) to the main module ( 12 ).
12. The apparatus of claim 11 , further characterized in that the main module ( 12 ) provides a position for the instant when the trigger signal is received by the main module ( 12 ), and the cellular module ( 11 ) is responsive to the position, and provides the position to the base station.
13. A system, comprising an apparatus according to claim 11 , and further comprising the beacons ( 27 ) of the positioning system that provide the ranging signals and also comprising the base station receiving the information for relating to a time value, according to the predetermined time reference, the instant at which the trigger signal is provided.
14. A system, comprising an apparatus according to claim 10 , and further comprising a cellular base station ( 24 ), for providing the cellular frame.
15. A system, comprising an apparatus according to claim 10 , and further comprising the beacons ( 27 ) of the positioning system that provide the ranging signals.
16. A method for having a ranging receiver ( 10 ), operative in communication with a positioning system and also operative in communication with a cellular communication system, provide information to a base station of the cellular communication system of use in enabling the base station to synchronize to time according to the positioning system, the ranging receiver ( 10 ) including a cellular module ( 12 ) adapted for communication with the cellular communication system and also including a main module ( 12 ) adapted for communication with the positioning system, the method characterized by:
a) a step ( 32 ) in which the cellular module ( 11 ) detects a portion of a downlink frame signal and provides a corresponding trigger signal to the main module ( 12 ) via a connection so constructed that any delay between applying a signal and receiving the signal is either negligible or can be determined;
b) a step ( 40 ) in which the apparatus ( 10 ) relates the instant at which the trigger signal is provided by the cellular module ( 11 ) to a time value according to the predetermined time reference; and
c) a step ( 40 ) in which the cellular module provides to the cellular communication system information about the relationship of the downlink frame signal to a time value according to the predetermined time reference.
17. The method of claim 16 , further characterized by a step ( 38 40 ) in which the main module ( 12 ) provides a position for the instant when the trigger signal is received by the main module ( 12 ), and the cellular module ( 11 ) is responsive to the position, and provides the position to the base station.