US 6,748,202 B2 · Method, apparatus and system for synchronizing a cellular communication system to GPS time

Abstract

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.

Claims17

Dependent claims

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 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;
and
the main module (12) provides the signal indicating the information for relating 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 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.

5 more elements

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 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 time-stamped frame and applies a trigger signal to a connection linking the cellular module (11) to the main module (12), a connection so constructed that any delay between applying a signal and receiving the signal is either negligible or can be determined;
and
b) a step (40) in which the main module (12) sends to the cellular module (11) a time value according to the positioning system for the instant when the main module (12) received the trigger signal, based on performing a navigation solution yielding a time value for an instant of time able to be related to the instant of time when the trigger signal was received using a local clock (20) accessible to the main module (12).

Dependencies are inferred from the claim text.

Method, apparatus and system for synchronizing a cellular communication system to GPS time

Life of this patent

Method, apparatus and system for synchronizing a cellular communication system to GPS time

Life of this patent

Abstract

Claims17