High efficiency WLAN preamble structure

• US 9,780,919 B2
• Filed: 07/02/2014
• Issued: 10/03/2017
• Est. Priority Date: 07/05/2013
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Vermani, Sameer, Tian, Bin, Van Zelst, Albert, Van Nee, Didier Johannes Richard, Tandra, Rahul, Doan, Dung Ngoc, Tian, Tao
• Primary Examiner(s): Pham, Chi H
• Assistant Examiner(s): Agureyev, Vladislav
• Application Number:
  US14/322,048
• Publication Number:
  US 20150009894A1
• Time in Patent Office: 1,189 Days
• Field of Search: None
• CPC Class Codes: H04L 1/0007 by modifying the frame length
• CPC Class Codes: H04L 1/0072 Error control for data other than payload data, e.g. control data
• CPC Class Codes: H04L 27/2602 Signal structure
• CPC Class Codes: H04L 27/26025 Numerology, i.e. varying one or more of symbol duration, subcarrier spacing, Fourier transform size, sampling rate or down-clocking allocating sub-channels of the transmission path H04L5/003
• CPC Class Codes: H04L 27/2603 Signal structure ensuring backward compatibility with legacy system
• CPC Class Codes: H04L 27/2657 Carrier synchronisation
• CPC Class Codes: H04L 5/0053 Allocation of signaling, i.e. of overhead other than pilot signals
• CPC Class Codes: H04W 56/0035 detecting errors in frequency or phase
• CPC Class Codes: H04W 74/0808 using carrier sensing, e.g. carrier sense multiple access [CSMA]
• CPC Class Codes: H04W 84/12 WLAN [Wireless Local Area Networks]

Abstract

Aspects of the present disclosure provide example preamble formats with repeated signal (SIG) fields that may help provide backwards compatibility and help address the effects of larger delay spreads in various wireless bands (e.g., WiFi bands).

Claims

1. A method for wireless communications, comprising:

generating a packet having a preamble decodable by a first type of device having a first set of capabilities and a second type of device having a second set of capabilities, wherein the preamble comprises a SIG field decodable by the first type of device and at least one repeated signal (SIG) field, wherein a guard interval is positioned between the SIG field decodable by the first type of device and at least a first portion of the repeated SIG field, wherein the SIG field and the repeated SIG field is repeated in a manner that allow the first type of device to detect a type of the packet, wherein the repeated SIG field that provides delay spread protection to at least one of the first type of device or second type of device, and wherein the repeated SIG field is decodable by the second type of device but not the first type of device; and

transmitting the packet.

2. The method of claim 1, wherein:

an indication of a type of packet is provided to the second type of device via an orthogonal rail of the SIG field decodable by the first type of device.

3. The method of claim 1, wherein an indication of a type of the packet is provided via an orthogonal rail of a SIG field decodable by the first type of device.

4. The method of claim 1, wherein an indication of a type of the packet is provided via a checksum in the repeated SIG field.

6. The method of claim 1, wherein a second portion of the repeated SIG field is also preceded by a guard interval.

7. The method of claim 1, wherein a second portion of the repeated SIG field is truncated relative to a first portion of the repeated SIG field.

8. The method of claim 1, wherein at least a portion of the preamble after the repeated SIG field is transmitted using an increased symbol duration or increased cyclic prefix relative to one or more fields of the preamble to provide delay spread protection.

9. The method of claim 8, wherein an indication of a type of delay spread protection is signaled prior to an end of the repeated SIG field.

10. The method of claim 1, wherein the repeated SIG field is repeated in a manner that allows the first type of device to detect the type of the packet by repeating the at least one repeated SIG field in time.

11. The method of claim 1, wherein the repeated SIG field is repeated in a manner that allows the first type of device to detect the type of the packet by repeating the at least one repeated SIG field in frequency.

12. The method of claim 1, wherein the at least one repeated SIG field comprises:

a first repeated SIG field that is decodable by the second type of device, but not the first type of device; and

a second repeated SIG field that is decodable by at least the first type of device.

13. The method of claim 1, wherein at least a portion of the packet is transmitted with a lower rate than at least a portion of the preamble.

14. The method of claim 1, wherein the preamble comprises at least two repeated SIG fields.

15. The method of claim 14, wherein at least one of the repeated SIG field is repeated in time.

16. The method of claim 14, wherein at least one of the repeated SIG field is repeated in frequency.

17. The method of claim 14, wherein the repeated SIG field comprises at least one repeated high efficiency (HE)-SIG0 field and at least one repeated HE-SIG1 field.

18. The method of claim 1, wherein the at least one repeated signal (SIG) field comprises a partially repeated SIG field.

19. The method of claim 18, wherein the partially repeated SIG field is transmitted:

using a set of tones to transmit a first symbol of the at least one repeated SIG field; and

using a limited subset of the set of tones to transmit a second symbol of the at least one repeated SIG field.

5. The method of 1, wherein the repeated SIG field is repeated in a manner that allows the first type of device to detect the type of the packet by rotating at least one symbol of the repeated SIG field relative to the SIG field decodable by the first type of device.

20. A method for wireless communications, comprising:

receiving a packet having a preamble decodable by a first type of device having a first set of capabilities and a second type of device having a second set of capabilities, wherein the preamble comprises a SIG field decodable by the first type of device and at least one repeated signal (SIG) field, wherein a guard interval is positioned between the SIG field decodable by the first type of device and at least a first portion of the repeated SIG field, wherein the SIG field and the repeated SIG field is repeated in a manner that allow the first type of device to detect a type of the packet, wherein the repeated SIG field that provides delay spread protection to at least one of the first type of device or second type of device, and wherein the repeated SIG field is decodable by the second type of device but not the first type of device; and

processing the repeated SIG field.

21. The method of claim 20, wherein:

an indication of a type of packet is provided to the second type of device via an orthogonal rail of the SIG field decodable by the first type of device.

22. The method of claim 20, wherein an indication of a type of the packet is provided via an orthogonal rail of a SIG field decodable by the first type of device.

23. The method of claim 20, wherein an indication of a type of the packet is provided via a checksum in the repeated SIG field.

24. The method of claim 20, wherein the repeated SIG field is repeated in a manner that allows the first type of device to detect the type of the packet by rotating at least one symbol of the repeated SIG field relative to the SIG field decodable by the first type of device.

25. The method of claim 20, further comprising determining a type of the packet via correlation of repeated portions of the repeated SIG field.

26. The method of claim 20, wherein at least a portion of the preamble after the repeated SIG field is transmitted using an increased symbol duration or increased cyclic prefix relative to one or more fields of the preamble to provide delay spread protection.

27. The method of claim 26, wherein at least a portion of the packet after the repeated SIG field in the preamble is transmitted with a larger cyclic prefix relative to one or more fields of the preamble and at least portion after that is transmitted with a longer symbol durations.

28. The method of claim 26, wherein portions of the packet after the at least a portion transmitted with an increased symbol duration or increased cyclic prefix are transmitted with normal symbol duration.

29. The method of claim 26, wherein an indication of a type of delay spread protection is signaled prior to an end of the repeated SIG field.

30. The method of claim 29, wherein the repeated SIG field is repeated in a manner that allows the first type of device to detect the type of the packet by repeating the at least one repeated SIG field in time.

31. The method of claim 29, wherein the repeated SIG field is repeated in a manner that allows the first type of device to detect the type of the packet by repeating the at least one repeated SIG field in frequency.

32. The method of claim 20, wherein the at least one repeated SIG field comprises:

a first repeated SIG field that is decodable by the second type of device, but not the first type of device; and

a second repeated SIG field that is decodable by at least the first type of device.

33. The method of claim 20, wherein at least a portion of the packet is transmitted with a lower rate than at least a portion of the preamble.

34. The method of claim 20, wherein the preamble comprises at least two repeated SIG fields.

35. The method of claim 20, wherein:

a set of tones of a first symbol of the repeated SIG field are used for pilots; and

at least a subset of the same set of tones in a second symbol of the repeated SIG field is used to signal a type of delay spread protection.

36. The method of claim 20, wherein a type of delay spread protection is signaled using an orthogonal rail of a repeated SIG field across at least 2 symbols.

37. The method of claim 20, wherein a type of delay spread protection is signaled using non-pilot tones of a repeated SIG field.

38. The method of claim 20, wherein:

a set of tones of a first symbol of the repeated SIG field are used for pilots; and

at least a subset of the same set of tones in a second symbol of the repeated SIG field is used to signal a type of delay spread protection.

39. The method of claim 20, wherein a type of delay spread protection is signaled using an orthogonal rail of a repeated SIG field across at least 2 symbols.

40. The method of claim 20, further comprising detecting a type of delay spread protection by calculating the auto-correlation of 2 symbols after a first repeated SIG field.

41. The method of claim 20, wherein a high efficiency WLAN type of packet is signaled using non-pilot tones of a repeated SIG field.

42. The method of claim 20, wherein the at least one repeated signal (SIG) field comprises a partially repeated SIG field.

43. The method of claim 42, wherein the partially repeated SIG field is received:

using a set of tones to receive a first symbol of the at least one repeated SIG field; and

using a limited subset of the set of tones to receive a second symbol of the at least one repeated SIG field.

44. An apparatus for wireless communications, comprising:

means for generating a packet having a preamble decodable by a first type of device having a first set of capabilities and a second type of device having a second set of capabilities, wherein the preamble comprises a SIG field decodable by the first type of device and at least one repeated signal (SIG) field, wherein a guard interval is positioned between the SIG field decodable by the first type of device and at least a first portion of the repeated SIG field, wherein the SIG field and the repeated SIG field is repeated in a manner that allow the first type of device to detect a type of the packet, wherein the repeated SIG field that provides delay spread protection to at least one of the first type of device or second type of device, and wherein the repeated SIG field is decodable by the second type of device but not the first type of device; and

means for transmitting the packet.

45. An apparatus for wireless communications, comprising:

means for receiving a packet having a preamble decodable by a first type of device having a first set of capabilities and a second type of device having a second set of capabilities, wherein the preamble comprises a SIG field decodable by the first type of device and at least one repeated signal (SIG) field, and wherein a guard interval is present between the SIG field decodable by the first type of device and the at least one repeated SIG field, wherein the SIG field and the repeated SIG field is repeated in a manner that allow the first type of device to detect a type of the packet, wherein the repeated SIG field that provides delay spread protection to at least one of the first type of device or second type of device, and wherein the repeated SIG field is decodable by the second type of device but not the first type of device; and

means for processing the repeated SIG field.

46. An apparatus for wireless communications, comprising:

a processing system configured to generate a packet having a preamble decodable by a first type of device having a first set of capabilities and a second type of device having a second set of capabilities, wherein the preamble comprises a SIG field decodable by the first type of device and at least one repeated signal (SIG) field, wherein a guard interval is positioned between the SIG field decodable by the first type of device and at least a first portion of the repeated SIG field, wherein the SIG field and the repeated SIG field is repeated in a manner that allow the first type of device to detect a type of the packet, wherein the repeated SIG field that provides delay spread protection to at least one of the first type of device or second type of device, and wherein the repeated SIG field is decodable by the second type of device but not the first type of device; and

a transmitter configured to transmit the packet.

47. An apparatus for wireless communications, comprising:

a receiver configured to receive a packet having a preamble decodable by a first type of device having a first set of capabilities and a second type of device having a second set of capabilities, wherein the preamble comprises a SIG field decodable by the first type of device and at least one repeated signal (SIG) field, and wherein a guard interval is present between the SIG field decodable by the first type of device and the at least one repeated SIG field, wherein the SIG field and the repeated SIG field is repeated in a manner that allow the first type of device to detect a type of the packet, wherein the repeated SIG field that provides delay spread protection to at least one of the first type of device or second type of device, and wherein the repeated SIG field is decodable by the second type of device but not the first type of device; and

a processing system configured to process the repeated SIG field.