Frame sync across multiple channels

• US 9,088,406 B2
• Filed: 07/29/2012
• Issued: 07/21/2015
• Est. Priority Date: 07/29/2012
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Newham, Adam E., Linsky, Joel Benjamin, Sauhta, Rohit, Miller, Brian F., Bartig, Kevin Wayne
• Primary Examiner(s): SMITH, CREIGHTON H
• Application Number:
  US13/561,077
• Publication Number:
  US 20140029701A1
• Time in Patent Office: 1,087 Days
• Field of Search: 700/94, 711/216
• US Class Current: 1/1
• CPC Class Codes: H04J 3/0652 Synchronisation among time division multiple access [TDMA] nodes, e.g. time triggered protocol [TTP] bus network with centralized control in which slots are of a TDMA packet structure H04L12/4035
• CPC Class Codes: H04L 7/041 using special codes as synchronising signal
• CPC Class Codes: H04R 2420/07 Applications of wireless loudspeakers or wireless microphones
• CPC Class Codes: H04S 1/005 For headphones
• CPC Class Codes: H04W 56/0015 one node acting as a reference for the others

Abstract

Systems, methods, and devices synchronize data streams by hashing received data frames to generate a sequence of hash values, comparing the generated hash value sequence to a hash value sequence received in a control stream, and processing data frames when the hash value sequences match. A source device and multiple receiver devices may synchronize audio data encoded in data frames, applying a hash function to each data frame to generate a first sequence of hash values, transmitting the data frames on a first channel and the first sequence of hash values on a control channel, receiving the data frames and the first sequence of hash values in the receiver devices, applying the hash algorithm to received data frames to generate a second sequence of hash values, comparing the first and second sequences of hash values, and processing data frames when the first and second sequences of hash values match.

Claims

1. A method of processing a data stream within a receiver device, comprising:

receiving a sequence of data frames in the receiver device via a first wireless communication link;

applying a hash algorithm to the received data frames to generate a first sequence of hash values;

receiving a control stream comprising a second sequence of hash values;

comparing the first and second sequences of hash values; and

determining when to begin processing received data frames based upon when the first and second sequences of hash values match.

2. The method of claim 1, wherein determining when to begin processing received data frames based upon when the first and second sequences of hash values match comprises beginning to process audio data frames in order to generate sound, and wherein the receiver device is one of a plurality of wireless speaker devices.

3. The method of claim 1, wherein:

the sequence of data frames comprises an audio data stream;

receiving the control stream comprising the second sequence of hash values comprises receiving a control stream that includes timestamp information; and

determining when to begin processing received data frames based upon when the first and second sequences of hash values match comprises determining when to begin decoding the audio data stream when the timestamp information matches a network clock signal.

4. The method of claim 1, wherein:

the sequence of data frames comprises an audio data stream;

receiving the control stream comprising the second sequence of hash values comprises receiving a control stream that includes clock information; and

determining when to begin processing received data frames based upon when the first and second sequences of hash values match comprises determining when to begin decoding the audio data stream based upon received clock information and a network clock.

5. The method of claim 1, further comprising:

storing the received data frames in a buffer; and

generating a new second sequence of hashes based on most recently received data frames stored in the buffer when the first and second sequences of hash values do not match.

6. The method of claim 1, wherein applying the hash algorithm to the received data frames comprises applying a cyclic redundancy check to the received data frames.

7. The method of claim 1, wherein applying a hash algorithm to the received data frames comprises applying a forward error correction algorithm to the received data frames.

8. The method of claim 1, wherein comparing the first and second sequences of hash values comprises comparing a hash value for each received data frame to determine when there is a match.

9. The method of claim 1, wherein comparing the first and second sequences of hash values comprises comparing a sequence of hash values spanning a plurality of data frames to determine when a pattern of hash values match.

10. The method of claim 1, wherein the control stream is transmitted as part of the first wireless communication link, and receiving the control stream comprising the second sequence of hash values comprises receiving the control stream from the first wireless communication link.

11. The method of claim 1, wherein the control stream is transmitted via a second wireless communication link different from the first wireless communication link, and receiving the control stream comprising the second sequence of hash values comprises receiving the control stream from the second wireless communication link.

12. A wireless communication device, comprising:

a wireless receiver circuit configured to receive data frames and a control stream over a wireless communication link; and

a processor coupled to the wireless receiver circuit and configured with processor-executable instructions to perform operations comprising;

receiving a sequence of data frames in a receiver device via a first wireless communication link;

applying a hash algorithm to the received data frames to generate a first sequence of hash values;

receiving a control stream comprising a second sequence of hash values;

comparing the first and second sequences of hash values; and

determining when to begin processing received data frames based upon when the first and second sequences of hash values match.

13. The wireless communication device of claim 12, wherein the processor is configured with processor-executable instructions to perform operations such that determining when to begin processing received data frames based upon when the first and second sequences of hash values match comprises beginning to process audio data frames in order to generate sound, and wherein the wireless communication device is one of a plurality of wireless communication devices.

14. The wireless communication device of claim 12, wherein the processor is configured with processor-executable instructions to perform operations such that:

the received sequence of data frames comprises an audio data stream;

receiving the control stream comprising the second sequence of hash values comprises receiving a control stream that includes timestamp information; and

determining when to begin processing received data frames based upon when the first and second sequences of hash values match comprises determining when to begin decoding the audio data stream when the timestamp information matches a network clock signal.

15. The wireless communication device of claim 12, wherein the processor is configured with processor-executable instructions to perform operations such that:

the sequence of data frames comprises an audio data stream;

receiving the control stream comprising the second sequence of hash values comprises receiving a control stream that includes clock information; and

determining when to begin processing received data frames based upon when the first and second sequences of hash values match comprises determining when to begin decoding the audio data stream based upon received clock information and a network clock.

16. The wireless communication device of claim 12, wherein the processor is configured with processor-executable instructions to perform operations further comprising:

storing the received data frames in a buffer; and

generating a new second sequence of hashes based on most recently received data frames stored in the buffer when the first and second sequences of hash values do not match.

17. The wireless communication device of claim 12, wherein the processor is configured with processor-executable instructions to perform operations such that applying the hash algorithm to the received data frames comprises applying a cyclic redundancy check to the received data frames.

18. The wireless communication device of claim 12, wherein the processor is configured with processor-executable instructions to perform operations such that applying the hash algorithm to the received data frames comprises applying a forward error correction algorithm to the received data frames.

19. The wireless communication device of claim 12, wherein the processor is configured with processor-executable instructions to perform operations such that comparing the first and second sequences of hash values comprises comparing a hash value for each received data frame to determine when there is a match.

20. The wireless communication device of claim 12, wherein the processor is configured with processor-executable instructions to perform operations such that comparing the first and second sequences of hash values comprises comparing a sequence of hash values spanning a plurality of data frames to determine when a pattern of hash values match.

21. The wireless communication device of claim 12, wherein the processor is configured with processor-executable instructions to perform operations such that receiving the control stream comprising the second sequence of hash values comprises receiving the control stream as part of the first wireless communication link.

22. The wireless communication device of claim 12, wherein the processor is configured with processor-executable instructions to perform operations such that receiving the control stream comprising the second sequence of hash values comprises receiving the control stream via a second wireless communication link different from the first wireless communication link.

33. The wireless communication device of claim 12, further comprising means for receiving the control stream via a second wireless communication link different from the first wireless communication link.

23. A wireless communication device, comprising:

means for receiving a sequence of data frames in a receiver device via a first wireless communication link;

means for applying a hash algorithm to the received data frames to generate a first sequence of hash values;

means for receiving a control stream comprising a second sequence of hash values;

means for comparing the first and second sequences of hash values; and

means for determining when to begin processing received data frames based upon when the first and second sequences of hash values match.

24. The wireless communication device of claim 23, wherein means for determining when to begin processing received data frames based upon when the first and second sequences of hash values match comprises means for beginning to process audio data frames in order to generate sound, and wherein the wireless communication device is one of a plurality of wireless communication devices.

25. The wireless communication device of claim 23, wherein:

the sequence of data frames comprises an audio data stream;

means for receiving the control stream comprising the second sequence of hash values comprises means for receiving a control stream that includes timestamp information; and

means for determining when to begin processing received data frames based upon when the first and second sequences of hash values match comprises means for determining when to begin decoding the audio data stream when the timestamp information matches a network clock signal.

26. The wireless communication device of claim 23, wherein:

the sequence of data frames comprises an audio data stream;

means for receiving the control stream comprising the second sequence of hash values comprises means for receiving a control stream that includes clock information; and

means for determining when to begin processing received data frames based upon when the first and second sequences of hash values match comprises means for determining when to begin decoding the audio data stream based upon received clock information and a network clock.

27. The wireless communication device of claim 23, further comprising:

means for storing the received data frames in a buffer; and

means for generating a new second sequence of hashes based on most recently received data frames stored in the buffer when the first and second sequences of hash values do not match.

28. The wireless communication device of claim 23, wherein means for applying the hash algorithm to the received data frames comprises means for applying a cyclic redundancy check to the received data frames.

29. The wireless communication device of claim 23, wherein means for applying the hash algorithm to the received data frames comprises means for applying a forward error correction algorithm to the received data frames.

30. The wireless communication device of claim 23, wherein means for comparing the first and second sequences of hash values comprises means for comparing a hash value for each received data frame to determine when there is a match.

31. The wireless communication device of claim 23, wherein means for comparing the first and second sequences of hash values comprises means for comparing a sequence of hash values spanning a plurality of data frames to determine when a pattern of hash values match.

32. The wireless communication device of claim 23, further comprising means for receiving the control stream as part of the first wireless communication link.

34. A non-transitory processor-readable storage medium having stored thereon processor-executable instructions configured to cause a communication device processor to perform operations comprising:

receiving a sequence of data frames in a receiver device via a first wireless communication link;

applying a hash algorithm to the received data frames to generate a first sequence of hash values;

receiving a control stream comprising a second sequence of hash values;

comparing the first and second sequences of hash values; and

determining when to begin processing received data frames based upon when the first and second sequences of hash values match.

35. The non-transitory processor-readable storage medium of claim 34, wherein the stored processor-executable instructions are configured to cause a communication device processor to perform operations such that determining when to begin processing received data frames based upon when the first and second sequences of hash values match comprises beginning to process audio data frames in order to generate sound, and wherein the communication device is one of a plurality of wireless communication devices.

36. The non-transitory processor-readable storage medium of claim 34, wherein the stored processor-executable instructions are configured to cause a communication device processor to perform operations such that:

the sequence of data frames comprises an audio data stream;

receiving the control stream comprising the second sequence of hash values comprises receiving a control stream that includes timestamp information; and

determining when to begin processing received data frames based upon when the first and second sequences of hash values match comprises determining when to begin decoding the audio data stream when the timestamp information matches a network clock signal.

37. The non-transitory processor-readable storage medium of claim 34, wherein the stored processor-executable instructions are configured to cause a communication device processor to perform operations such that:

the sequence of data frames comprises an audio data stream;

receiving the control stream comprising the second sequence of hash values comprises receiving a control stream that includes clock information; and

determining when to begin processing received data frames based upon when the first and second sequences of hash values match comprises determining when to begin decoding the audio data stream based upon received clock information and a network clock.

38. The non-transitory processor-readable storage medium of claim 34, wherein the stored processor-executable instructions are configured to cause a communication device processor to perform operations further comprising:

storing the received data frames in a buffer; and

generating a new second sequence of hashes based on most recently received data frames stored in the buffer when the first and second sequences of hash values do not match.

39. The non-transitory processor-readable storage medium of claim 34, wherein the stored processor-executable instructions are configured to cause a communication device processor to perform operations such that applying the hash algorithm to the received data frames comprises applying a cyclic redundancy check to the received data frames.

40. The non-transitory processor-readable storage medium of claim 34, wherein the stored processor-executable instructions are configured to cause a communication device processor to perform operations such that applying the hash algorithm to the received data frames comprises applying a forward error correction algorithm to the received data frames.

41. The non-transitory processor-readable storage medium of claim 34, wherein the stored processor-executable instructions are configured to cause a communication device processor to perform operations such that comparing the first and second sequences of hash values comprises comparing a hash value for each received data frame to determine when there is a match.

42. The non-transitory processor-readable storage medium of claim 34, wherein the stored processor-executable instructions are configured to cause a communication device processor to perform operations such that comparing the first and second sequences of hash values comprises comparing a sequence of hash values spanning a plurality of data frames to determine when a pattern of hash values match.

43. The non-transitory processor-readable storage medium of claim 34, wherein the stored processor-executable instructions are configured to cause a communication device processor to perform operations such that receiving the control stream comprising the second sequence of hash values comprises receiving the control stream as part of the first wireless communication link.

44. The non-transitory processor-readable storage medium of claim 34, wherein the stored processor-executable instructions are configured to cause a communication device processor to perform operations such that receiving the control stream comprising the second sequence of hash values comprises receiving the control stream via a second wireless communication link different from the first wireless communication link.

45. A method of synchronizing audio data transmitted by a source device to multiple receiver devices, comprising:

encoding audio data into a sequence of data frames;

applying a hash algorithm to each of the data frames to generate a first sequence of hash values;

transmitting the data frames on a first channel;

transmitting the first sequence of hash values on a control channel;

receiving the data frames and the first sequence of hash values in each of the multiple receiver devices;

applying the hash algorithm in each of the multiple receiver devices to the received data frames to generate a second sequence of hash values;

comparing the first and second sequences of hash values in each of the multiple receiver devices; and

beginning to process received data frames in each of the multiple receiver devices when the first and second sequences of hash values match.

46. The method of claim 45, wherein:

the multiple receiver devices comprise first and second speaker devices; and

beginning to process received data frames in each of the multiple receiver devices when the first and second sequences of hash values match comprises beginning to decode the data frames in each of the first and second speaker devices so that audio is generated by the first and second speaker devices that is synchronized within a single 48 KHz sample.

47. The method of claim 45, wherein transmitting the first sequence of hash values on the control channel comprises transmitting the first sequence of hash values on a control channel as part of a wireless communication link that also transmits the first channel.

48. The method of claim 45, wherein transmitting the first sequence of hash values on the control channel comprises transmitting the first sequence of hash values on a control channel via a wireless communication link that is different from the first channel.

49. A communication system, comprising:

a wireless data source device; and

a plurality of receiver devices,

wherein the wireless data source device comprises;

a wireless transceiver; and

a source device processor coupled to the wireless transceiver and configured with processor-executable instructions to perform operations comprising;

encoding audio data into a sequence of data frames;

applying a hash algorithm to each of the data frames to generate a first sequence of hash values;

transmitting the data frames on a first channel, and

transmitting the first sequence of hash values on a control channel;

wherein each of the plurality of receiver devices comprises;

a wireless receiver circuit; and

a receiver device processor coupled to the wireless receiver circuit and configured with processor-executable instructions to perform operations comprising;

receiving the data frames and the first sequence of hash values;

applying the hash algorithm to the received data frames to generate a second sequence of hash values;

comparing the first and second sequences of hash values; and

beginning to process received data frames when the first and second sequences of hash values match.

50. The communication system of claim 49, wherein:

the plurality of receiver devices comprise first and second speaker devices; and

the receiver device processor is configured with processor-executable instructions to perform operations such that beginning to process received data frames in each of the plurality of receiver devices when the first and second sequences of hash values match comprises beginning to decode the data frames in each of the first and second speaker devices so that audio is generated by the first and second speaker devices that is synchronized within a single 48 KHz sample.

51. The communication system of claim 49, wherein the source device processor is configured with processor-executable instructions to perform operations such that transmitting the first sequence of hash values on the control channel comprises transmitting the first sequence of hash values on a control channel as part of a wireless communication link that also transmits the first channel.

52. The communication system of claim 49, wherein the source device processor is configured with processor-executable instructions to perform operations such that transmitting the first sequence of hash values on the control channel comprises transmitting the first sequence of hash values on a control channel via a wireless communication link that is different from the first channel.

53. A communication system, comprising:

a wireless data source device comprising;

means for encoding audio data into a sequence of data frames;

means for applying a hash algorithm to each of the data frames to generate a first sequence of hash values;

means for transmitting the data frames on a first channel, and

means for transmitting the first sequence of hash values on a control channel; and

a plurality of receiver devices, each of the plurality of receiver devices comprising;

means for receiving the data frames and the first sequence of hash values;

means for applying the hash algorithm to the received data frames to generate a second sequence of hash values;

means for comparing the first and second sequences of hash values; and

means for beginning to process received data frames when the first and second sequences of hash values match.

54. The communication system of claim 53, wherein:

the plurality of receiver devices further comprise first and second speaker devices; and

means for beginning to process received data frames in each of the plurality of receiver devices when the first and second sequences of hash values match comprises means for beginning to decode the data frames in each of the first and second speaker devices so that audio is generated by the first and second speaker devices that is synchronized within a single 48 KHz sample.

55. The communication system of claim 53, wherein means for transmitting the first sequence of hash values on a control channel comprises means for transmitting the first sequence of hash values on a control channel as part of a wireless communication link that also transmits the first channel.

56. The communication system of claim 53, wherein means for transmitting the first sequence of hash values on the control channel comprises means for transmitting the first sequence of hash values on a control channel via a wireless communication link that is different from the first channel.

57. A non-transitory processor-readable storage medium having stored thereon processor-executable instructions configured to be executed by a wireless data source device processor and processors of a plurality of wireless receiver devices,

wherein the stored processor-executable instructions configured to be executed by processor of a wireless data source device are configured to cause the processor to perform operations comprising:

encoding audio data into a sequence of data frames;

applying a hash algorithm to each of the data frames to generate a first sequence of hash values;

transmitting the data frames on a first channel, and

transmitting the first sequence of hash values on a control channel, and

wherein the stored processor-executable instructions configured to be executed by processors of the plurality of wireless receiver devices are configured to cause the processor to perform operations comprising;

receiving the data frames and the first sequence of hash values;

applying the hash algorithm to the received data frames to generate a second sequence of hash values;

comparing the first and second sequences of hash values; and

beginning to process received data frames when the first and second sequences of hash values match.

58. The non-transitory processor-readable storage medium of claim 57, wherein the stored processor-executable instructions configured to be executed by processors of the plurality of wireless receiver devices are configured to cause the processor to perform operations such that beginning to process received data frames when the first and second sequences of hash values match comprises beginning to decode the data frames in each of the first and second speaker devices so that audio is generated by the first and second speaker devices that is synchronized within a single 48 KHz sample.

59. The non-transitory processor-readable storage medium of claim 57, wherein the stored processor-executable instructions configured to be executed by a wireless data source device processor are configured to cause the processor to perform operations such that transmitting the first sequence of hash values on the control channel comprises transmitting the first sequence of hash values on a control channel as part of a wireless communication link that also transmits the first channel.

60. The non-transitory processor-readable storage medium of claim 57, wherein the stored processor-executable instructions configured to be executed by a wireless data source device processor are configured to cause the processor to perform operations such that transmitting the first sequence of hash values on the control channel comprises transmitting the first sequence of hash values on a control channel via a wireless communication link that is different from the first channel.