Super-resolution technique for time-of-arrival estimation

• US 10,327,221 B1
• Filed: 05/25/2018
• Issued: 06/18/2019
• Est. Priority Date: 05/25/2018
• Status: Active Grant

• Current Assignee: Apple Inc.
• Original Assignee: Apple Inc.
• Inventors: Sarrigeorgidis, Konstantinos
• Primary Examiner(s): Malek, Leila
• Application Number:
  US15/989,266
• Time in Patent Office: 389 Days
• Field of Search: 375149
• CPC Class Codes: G01S 11/02 using radio waves G01S19/00 takes precedence
• CPC Class Codes: G01S 11/04 using angle measurements
• CPC Class Codes: G01S 11/08 using synchronised clocks
• CPC Class Codes: G01S 3/8006 Multi-channel systems specially adapted for direction-finding, i.e. having a single aerial system capable of giving simultaneous indications of the directions of different signals
• CPC Class Codes: H04B 1/7073 Synchronisation aspects
• CPC Class Codes: H04B 1/711 the interference being multi-path interference
• CPC Class Codes: H04B 2201/7073 Direct sequence modulation synchronisation
• CPC Class Codes: H04J 11/0026 of multi-user interference
• CPC Class Codes: H04L 25/0204 of multiple channels
• CPC Class Codes: H04L 25/0212 of impulse response
• CPC Class Codes: H04W 56/006 using known positions of transmitter and receiver
• CPC Class Codes: H04W 64/006 with additional information processing, e.g. for direction or speed determination

Abstract

An interface circuit in an electronic device may receive samples of wireless signals in one or more time intervals, where the wireless signals are associated with the second electronic device. For example, the samples of the wireless signals may include one or more of: time samples, spatial samples and/or frequency samples. Then, the interface circuit may split the samples of the wireless signals into parallel channels for sub-band processing that improves a resolution and/or a signal-to-noise ratio of the samples of the wireless signals. The sub-band processing may include filtering and decimation. Moreover, the sub-band processing may include a super-resolution technique, such as a multiple signal classification (MUSIC) technique and/or a linear-prediction super-resolution technique. Next, the interface circuit may combine outputs from the parallel channels to estimate a time of arrival of the wireless signals and/or a distance between the electronic device and the second electronic device.

Claims

1. An electronic device, comprising:

multiple nodes configured to communicatively couple to multiple antennas; and

an interface circuit, communicatively coupled to the multiple nodes, configured to communicate with a second electronic device, and configured to;

receive samples of wireless signals in a time interval, wherein the wireless signals are associated with the second electronic device and the wireless signals have a fixed bandwidth;

split the samples of the wireless signals into a plurality of parallel channels;

perform sub-band processing on the samples of the plurality of parallel channels to improve a resolution of the samples, wherein the sub-band processing comprises filtering and decimation of at least a subset of the samples, and wherein the sub-band processing further comprises performing a super-resolution technique; and

combine outputs from the parallel channels to estimate a time of arrival of the wireless signals.

2. The electronic device of claim 1, wherein the samples of the wireless signals correspond to single instances of one or more multipath signals associated with a number of paths in a wireless environment of the electronic device.

3. The electronic device of claim 1, wherein the sub-band processing is configured to increase a signal-to-noise ratio of one or more of the samples of the wireless signals.

4. The electronic device of claim 1, wherein the interface circuit is configured to estimate a distance between the electronic device and the second electronic device based at least in part on the samples of the wireless signals and the estimated time of arrival.

5. The electronic device of claim 1, wherein the super-resolution technique comprises one of:

a multiple signal classification (MUSIC) technique or a linear-prediction super-resolution technique.

6. The electronic device of claim 1, wherein the samples of the wireless signals comprise one or more of:

time samples, spatial samples or frequency samples.

7. The electronic device of claim 1, wherein the communication with the second electronic device comprises ultra-wide-band communication.

8. An electronic device, comprising:

multiple nodes configured to communicatively couple to multiple antennas; and

an interface circuit, communicatively coupled to the multiple nodes, configured to communicate with a second electronic device, and configured to;

receive samples of wireless signals in a time interval, wherein the wireless signals are associated with the second electronic device and the wireless signals have a fixed bandwidth;

split the samples of the wireless signals into a plurality of parallel channels;

perform sub-band processing on the samples of the plurality of parallel channels to improve a resolution of the samples of the wireless signals, wherein the sub-band processing comprises filtering and decimation of at least a subset of the samples, and wherein the sub-band processing comprises a super-resolution technique; and

combine outputs from the parallel channels to determine a distance between the electronic device and the second electronic device.

9. The electronic device of claim 8, wherein the samples of the wireless signals correspond to single instances of one or more multipath signals associated with a number of paths in a wireless environment of the electronic device.

10. The electronic device of claim 8, wherein the sub-band processing is configured to increase a signal-to-noise ratio of one or more of the samples of the wireless signals.

11. The electronic device of claim 8, wherein the interface circuit is configured to determine a time of arrival of the wireless signals, and the determining of the distance is based at least in part on the outputs and the estimated time of arrival.

12. The electronic device of claim 8, wherein the super-resolution technique comprises one of:

a multiple signal classification (MUSIC) technique or a linear-prediction super-resolution technique.

13. The electronic device of claim 8, wherein the samples of the wireless signals comprise one or more of:

time samples, spatial samples or frequency samples.

14. The electronic device of claim 8, wherein the communication with the second electronic device comprises ultra-wide-band communication.

15. An electronic device, comprising:

a node configured to communicatively couple to an antenna; and

an interface circuit, communicatively coupled to the node, configured to communicate with a second electronic device, and configured to;

receive samples of wireless signals in multiple instances of a time interval, wherein the wireless signals are associated with the second electronic device and the wireless signals have a fixed bandwidth;

split the samples of the wireless signals into a plurality of parallel channels;

perform sub-band processing on the samples of the plurality of parallel channels to improve a resolution of the samples of the wireless signals, wherein the sub-band processing comprises filtering and decimation of at least a subset of the samples, and wherein the sub-band processing comprises a super-resolution technique; and

combine outputs from the parallel channels to estimate a time of arrival of the wireless signals.

16. The electronic device of claim 15, wherein the samples of the wireless signals in a given instance of the time interval correspond to single instances of one or more multipath signals associated with a number of paths in a wireless environment of the electronic device.

17. The electronic device of claim 15, wherein the sub-band processing is configured to increase a signal-to-noise ratio of one or more of the samples of the wireless signals.

18. The electronic device of claim 15, wherein the interface circuit is configured to determine a distance between the electronic device and the second electronic device based at least in part on the samples of the wireless signals and the estimated time of arrival.

19. The electronic device of claim 15, wherein the super-resolution technique comprises one of:

a multiple signal classification (MUSIC) technique or a linear-prediction super-resolution technique.

20. The electronic device of claim 15, wherein the samples of the wireless signals comprise one or more of:

time samples, or frequency samples.