Communications system

• US 10,274,601 B2
• Filed: 06/21/2018
• Issued: 04/30/2019
• Est. Priority Date: 07/17/2017
• Status: Active Grant

• Current Assignee: NXP B.V. (NXP Semiconductors NV)
• Original Assignee: NXP B.V. (NXP Semiconductors NV)
• Inventors: Roovers, Raf Lodewijk Jan
• Primary Examiner(s): Miller, Brandon J
• Application Number:
  US16/014,770
• Publication Number:
  US 20190018145A1
• Time in Patent Office: 313 Days
• CPC Class Codes: G01S 19/03 Cooperating elements; Interaction or communication between different cooperating elements or between cooperating elements and receivers
• CPC Class Codes: G01S 19/256 relating to timing, e.g. time of week, code phase, timing offset
• CPC Class Codes: G01S 19/396 Determining accuracy or reliability of position or pseudorange measurements
• CPC Class Codes: G01S 5/02216 Timing or synchronisation of the receivers
• CPC Class Codes: H03L 7/00 Automatic control of frequency or phase; Synchronisation
• CPC Class Codes: H03L 7/06 using a reference signal applied to a frequency- or phase-locked loop
• CPC Class Codes: H04W 56/0015 one node acting as a reference for the others
• CPC Class Codes: H04W 84/20 Master-slave selection or change arrangements

Abstract

A communications system comprising a master-node and a slave-node. The master-node comprising: a GNSS receiver configured to provide a GNSS based time reference signal; a master-timing-reference-calibrator configured to determine a master-timing-reference-calibration-signal, for calibrating the master reference timing circuit, based on the GNSS based time reference signal; and a master-reference-timing-circuit configured to provide a master-clock-signal based on the master-timing-reference-calibration-signal, wherein the master-clock-signal is a clock signal for the master-node; and a master-transmitter configured to determine a master-communications-signal using the master-clock signal. The slave-node comprising: a slave-receiver configured to receive the master-communications-signal from the master-node; a slave-timing-reference-calibrator configured to determine a slave-timing-reference-calibration-signal based on the master-communications-signal; and a slave-timing-reference-circuit configured to provide a slave-clock-signal based on the slave-timing-reference-calibration-signal, wherein the slave-clock-signal is a clock signal for the slave-node.

Claims

1. A communications system comprising:

a master-node comprising;

a GNSS receiver configured to provide a GNSS based time reference signal;

a GNSS-quality-monitor configured to determine a GNSS-timing-indicator that is representative of the quality of the GNSS based time reference signal, wherein a master-timing-reference-calibrator is configured to determine a master-timing-reference-calibration-signal based on the GNSS-timing-indicator;

the master-timing-reference-calibrator configured to determine the master-timing-reference-calibration-signal, for calibrating the master reference timing circuit, based on the GNSS based time reference signal

a master-reference-timing-circuit configured to provide a master-clock-signal based on the master-timing-reference-calibration-signal, wherein the master-clock-signal is a clock signal for the master-node; and

a master-transmitter configured to determine a master-communications-signal using the master-clock-signal;

a slave-node comprising;

a slave-receiver configured to receive the master-communications-signal from the master-node;

a slave-timing-reference-calibrator configured to determine a slave-timing-reference-calibration-signal based on the master-communications-signal; and

a slave-timing-reference-circuit configured to provide a slave-clock-signal based on the slave-timing-reference-calibration-signal, wherein the slave-clock-signal is a clock signal for the slave-node.

2. The communications system of claim 1, wherein:

the master-timing-reference-calibration-signal is representative of a master-timing-parameter for the master-reference-timing-circuit; and

the slave-timing-reference-calibration-signal is representative of a slave-timing-parameter for the slave-reference-timing-circuit.

3. The communications system of claim 1, wherein the master-reference-timing-circuit comprises a master-crystal-oscillator and/or the slave-timing-reference-circuit comprises a slave-crystal-oscillator.

4. The communications system of claim 1, wherein the master-transmitter comprises a master-MB-transmitter, the master-communications-signal comprises an ultra wide band communications signal, and the slave-receiver comprises a slave-UWB-receiver.

5. The communications system of claim 1, further comprising:

a master-calibrator-processor configured to determine a master-clock-reliability-indicator that is representative of the quality of the master-clock-signal; and

wherein the master-timing-reference-calibrator is configured to determine the master-timing-reference-calibration-signal based on the master-clock-reliability-indicator.

6. The communications system of claim 1, wherein:

the master-timing-reference-calibrator is configured to determine the master-timing-reference-calibration-signal based on a communications-quality-indicator;

the slave-timing-reference-calibrator is configured to determine the slave-timing-reference-calibration-signal based on the communications-quality-indicator; and

the communications-quality-indicator is representative of the quality of the communications link between the master-node and the slave-node.

7. The communications system of claim 1, further comprising:

a slave-calibrator-processor configured to determine a slave-clock-reliability-indicator that is representative of the quality of the slave-clock-signal; and

wherein the slave-timing-reference-calibrator is configured to determine the slave-timing-reference-calibration-signal based on the slave-clock-reliability-indicator.

8. The communications system of claim 1, further comprising:

a master-calibrator-processor configured to determine a master-clock-reliability-indicator that is representative of the quality of the master-clock-signal; and

wherein

the master-transmitter is configured to provide the master-clock-reliability-indicator to the slave-node;

the slave-receiver is configured to receive the master-clock-reliability-indicator from the master-node; and

the slave-timing-reference-calibrator is configured to determine the slave-timing-reference-calibration-signal based on the master-clock-reliability-indicator.

9. The communications system of claim 1, wherein the master-timing-reference-calibrator is configured to:

periodically determine the master-timing-reference-calibration-signal;

or

determine the master-timing-reference-calibration-signal in response to a master-calibration-trigger-signal.

10. The communications system of claim 9, further comprising a master-calibrator-processor configured to set the master-calibration-trigger-signal based on one or more of:

a master-temperature-value associated with the master-node; and

a master-clock-reliability-indicator that is representative of the quality of the master-clock-signal.

11. The communications system of claim 1, wherein the slave-timing-reference-calibrator is configured to determine the slave-timing-reference-calibration-signal in response to a slave-calibration-trigger-signal.

12. The communications system of claim 11, further comprising a slave-calibrator-processor configured to set the slave-calibration-trigger-signal based on one or more of:

a slave-temperature-value associated with the slave-node;

a communication-quality-indicator that is representative of the communications link between the master-node and the slave-node; and

a slave-clock-reliability-indicator that is representative of the quality of the slave-clock-signal.

13. The communications system of claim 1, further comprising:

a slave-calibrator-processor configured to determine a slave-timing-indicator that is representative of the quality of the slave-clock-signal; and

a master-calibrator-processor configured to determine a master-timing-indicator that is representative of the quality of the master-clock-signal; and

wherein

the slave-timing-reference-calibrator is configured to determine the slave-timing-reference-calibration-signal based on the master-timing-indicator and the slave-timing-indicator.

14. The communications system of claim 1, wherein the GNSS receiver is hard-wired to the master-timing-reference-calibrator.

15. A communications system comprising:

a master-node comprising;

a GNSS receiver configured to provide a GNSS based time reference signal;

a master-calibrator-processor configured to determine a master-clock-reliability-indicator that is representative of the quality of the master-clock-signal, wherein a master-timing-reference-calibrator is configured to determine a master-timing-reference-calibration-signal based on the master-clock-reliability-indicator;

the master-timing-reference-calibrator configured to determine the master-timing-reference-calibration-signal, for calibrating the master reference timing circuit, based on the GNSS based time reference signal; and

a master-reference-timing-circuit configured to provide a master-clock-signal based on the master-timing-reference-calibration-signal, wherein the master-clock-signal is a clock signal for the master-node; and

a master-transmitter configured to determine a master-communications-signal using the master-clock-signal;

a slave-node comprising;

a slave-receiver configured to receive the master-communications-signal from the master-node;

a slave-timing-reference-calibrator configured to determine a slave-timing-reference-calibration-signal based on the master-communications-signal; and

a slave-timing-reference-circuit configured to provide a slave-clock-signal based on the slave-timing-reference-calibration-signal, wherein the slave-clock-signal is a clock signal for the slave-node.