Systems and methods for adaptive frequency synchronization

• US 9,660,744 B1
• Filed: 01/13/2015
• Issued: 05/23/2017
• Est. Priority Date: 01/13/2015
• Status: Active Grant

• Current Assignee: Watchguard Video Incorporated (Motorola Solutions, Inc.)
• Original Assignee: Enforcement Video Incorporated (Enforcement Technology Group Incorporated)
• Inventors: Emberson, A. Thomas
• Primary Examiner(s): Rivero, Alejandro
• Application Number:
  US14/595,978
• Time in Patent Office: 861 Days
• Field of Search: None
• CPC Class Codes: H04B 1/713 using frequency hopping
• CPC Class Codes: H04B 1/715 Interference-related aspects
• CPC Class Codes: H04H 20/423 Transmitter side
• CPC Class Codes: H04H 20/71 Wireless systems
• CPC Class Codes: H04R 2420/07 Applications of wireless loudspeakers or wireless microphones
• CPC Class Codes: H04S 2400/15 Aspects of sound capture and related signal processing for recording or reproduction

Abstract

In one embodiment, a method includes receiving transmission segments from at least one device over a plurality of channels pursuant to a channel-switching schedule, the channel-switching schedule comprising an iteratively-repeated channel sequence. The iteratively-repeated channel sequence comprises a plurality of channels, the channel-switching schedule specifying an assigned transmission duration for each channel. In addition, the method includes, for at least one channel of the plurality of channels, detecting interference during a time segment of the assigned transmission duration, the time segment comprising at least one of a beginning portion and an ending portion of the assigned transmission duration. Further, the method includes responsive to the detected interference, determining to shift, by a specified quantity of time, a future channel switch indicated by the iteratively-repeated channel sequence.

Claims

1. A method comprising:

receiving transmission segments from at least one device pursuant to a channel-switching schedule, the channel-switching schedule comprising an iteratively-repeated channel sequence;

wherein the iteratively-repeated channel sequence comprises a plurality of channels, the channel-switching schedule specifying an assigned transmission duration for each channel, the assigned transmission duration for each channel comprising a plurality of time segments;

for at least one channel of the plurality of channels, detecting a pattern of interference during at least one of a first time segment and a last time segment of the plurality of time segments of the assigned transmission duration; and

responsive to the detected pattern of interference, automatically shifting, by a specified quantity of time that is less than the assigned transmission duration of the at least one channel, a future channel switch indicated by the iteratively-repeated channel sequence, such that the at least one of the first time segment and the last time segment is added to the assigned transmission duration of a neighboring channel in the iteratively-repeated channel sequence.

2. The method of claim 1, wherein the automatically shifting comprises delaying the future channel switch by the specified quantity of time.

3. The method of claim 1, wherein the automatically shifting comprises accelerating the future channel switch by the specified quantity of time.

4. The method of claim 1, wherein the automatically shifting comprises shifting an entirety of the channel-switching schedule by the specified quantity of time.

5. The method of claim 1, wherein the automatically shifting comprises synchronizing with the at least one device.

6. The method of claim 1, wherein the detecting comprises identifying an interference pattern in the plurality of channels.

7. The method of claim 1, wherein:

the detecting comprises determining interference during a same relative time period of the assigned transmission duration of multiple channels of the plurality of channels; and

the time segment corresponds to the same relative time period.

8. The method of claim 1, comprising,

for each channel of the plurality of channels, during each iteration of the channel, evaluating a reception quality related to the at least one device'"'"'s transmissions during each of a plurality of segments of the assigned transmission duration;

wherein the time segment comprises one or more contiguous segments of the plurality of segments of the assigned transmission duration for the at least one channel; and

wherein the detecting comprises determining that the reception quality during the time segment fails to satisfy at least one quality-related criterion.

9. The method of claim 8, wherein the evaluating comprises performing a data-integrity check.

10. The method of claim 1, wherein a plurality of receiver devices each independently perform the method such that the at least one device is distinct for each receiver device.

11. The method of claim 10, wherein each receiver device initially generates a same pseudorandom sequence, the pseudorandom sequence being used as the iteratively-repeated channel sequence.

12. The method claim 1, wherein the at least one device comprises a plurality of devices.

13. The method of claim 1, wherein the at least one device comprises a wireless microphone.

14. A system comprising:

at least one processor, wherein the at least one processor is operable to implement a method comprising;

receiving transmission segments from at least one device pursuant to a channel-switching schedule, the channel-switching schedule comprising an iteratively-repeated channel sequence;

wherein the iteratively-repeated channel sequence comprises a plurality of channels, the channel-switching schedule specifying an assigned transmission duration for each channel, the assigned transmission duration for each channel comprising a plurality of time segments;

for at least one channel of the plurality of channels, detecting a pattern of interference during at least one of a first time segment and a last time segment of the plurality of time segments of the assigned transmission duration; and

responsive to the detected pattern of interference, automatically shifting, by a specified quantity of time that is less than the assigned transmission duration of the at least one channel, a future channel switch indicated by the iteratively-repeated channel sequence, such that the at least one of the first time segment and the last time segment is added to the assigned transmission duration of a neighboring channel in the iteratively-repeated channel sequence.

15. The system of claim 14, wherein the automatically shifting comprises delaying the future channel switch by the specified quantity of time.

16. The system of claim 14, wherein the automatically shifting comprises accelerating the future channel switch by the specified quantity of time.

17. The system of claim 14, wherein the automatically shifting comprises shifting an entirety of the channel-switching schedule by the specified quantity of time.

18. The system of claim 14, wherein the automatically shifting comprises synchronizing with the at least one device.

19. The system of claim 14, wherein the detecting comprises identifying an interference pattern in the plurality of channels.

20. A computer-program product comprising a non-transitory computer-usable medium having computer-readable program code embodied therein, the computer-readable program code adapted to be executed to implement a method comprising:

receiving transmission segments from at least one device over a plurality of channels pursuant to a channel-switching schedule, the channel-switching schedule comprising an iteratively-repeated channel sequence;

wherein the iteratively-repeated channel sequence comprises a plurality of channels, the channel-switching schedule specifying an assigned transmission duration for each channel the assigned transmission duration for each channel comprising a plurality of time segments;

for at least one channel of the plurality of channels, detecting a pattern of interference during at least one of a first time segment and a last time segment of the plurality of time segments of the assigned transmission duration; and

responsive to the detected pattern of interference, automatically shifting, by a specified quantity of time that is less than the assigned transmission duration of the at least one channel, a future channel switch indicated by the iteratively-repeated channel sequence, such that the at least one of the first time segment and the last time segment is added to the assigned transmission duration of a neighboring channel in the iteratively-repeated channel sequence.