US 2011/0085540 A1 · TIME SYNCHRONIZER

Abstract

An object of this invention is to realize stable control in a time synchronizer utilizing GPS satellites so that a long operational time is ensured for the system even if any of the GPS satellites becomes unable to be captured. When a base station becomes unable to capture any of the GPS satellites and if there is a mobile station which is in a relationship capable of performing handover from the base station to another base station, a radio wave input/output unit receives a frame transmitted by the other base station being able to normally receive the GPS satellite via the mobile station, and a frame timing detection unit estimates a deviation from the UTC. A 1 PPS correction circuit unit transmits a signal to correct the deviation, and a control unit causes a GPS receiver to change and adjust the frame timing. A frame generation unit generates a frame based on the corrected 1 PPS signal.

Claims12

Dependent claims

A time synchronizer for use in a base station relaying communication between mobile stations under clock synchronization based on a time signal received from any of GPS communication satellites, wherein the time synchronizer comprises:

a circuit which, when a base station becomes unable to capture any of the GPS communication satellites, acquires from another base station which is in a handover state, via a mobile station, time information of a time signal which the other base station receives from any of the GPS communication satellites;
and
a circuit performing its own clock synchronization based on the acquired time information.

a frame timing detection unit detecting timing information of a communication frame received by the communication;
a GPS receiver which normally outputs a 1 PPS signal and a clock synchronized with the time signal, whereas outputs alarm information when it becomes unable to receive the time signal;
a CPU circuit unit which, if there is another base station to which handover is possible when the alarm information is output, computes the timing of the 1 PPS signal in the other base station based on the timing information from the other base station, and obtains a phase difference based on a comparison result;
a 1 PPS correction circuit unit computing a phase correction amount based on the phase difference;
a control unit which normally outputs the 1 PPS signal from the GPS receiver, whereas when the alarm information is output, compares the computed 1 PPS signal timing with the timing of the 1 PPS signal from the GPS receiver, and outputs a comparison result to the CPU circuit unit and also outputs a 1 PPS signal phase-corrected by the GPS receiver based on the phase correction amount;
and
a frame generation unit generating a frame for the communication based on the 1 PPS signal from the control unit.

4 more elements

Dependencies are inferred from the claim text.

Time synchronizer

Life of this patent

Time synchronizer

Life of this patent

Abstract

Claims12