PREAMBLE DESIGN FOR TELEVISION WHITE SPACE TRANSMISSIONS

• US 20130128807A1
• Filed: 05/15/2012
• Published: 05/23/2013
• Est. Priority Date: 05/19/2011
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Vermani, Sameer, Abraham, Santosh Paul, Shellhammer, Stephen J., Jones, Vincent Knowles IV, van Zelst, Albert, van Nee, Didier Johannes Richard
• Granted Patent: US 8,830,815 B2
• Time in Patent Office: Days
• US Class Current: 370/328
• CPC Class Codes: H04L 27/2602 Signal structure
• CPC Class Codes: H04L 27/2603 Signal structure ensuring backward compatibility with legacy system
• CPC Class Codes: H04L 5/0053 Allocation of signaling, i.e. of overhead other than pilot signals
• CPC Class Codes: H04L 69/00 Network arrangements, protocols or services independent of the application payload and not provided for in the other groups of this subclass networks security protocols H04L9/40; wireless communication networks H04W
• CPC Class Codes: H04W 4/00 Services specially adapted for wireless communication networks; Facilities therefor

Abstract

A method for generating a Physical Layer Convergence Protocol Packet Data Unit (PPDU) having a preamble and a payload for television white space transmission (TVWS) is provided. The symbols of the PPDU each include 128 total (orthogonal frequency-division multiplexing) OFDM tones or 256 total OFDM tones. The preamble includes a signal (SIG) field symbol having 108 OFDM data tones if the symbols of the PPDU include 128 total OFDM tones or having 234 OFDM data tones if the symbols of the PPDU include 256 total OFDM tones. The SIG field symbol indicates at least one of an amount of data in the payload or a length of time that the PPDU will occupy the television broadcast frequency spectrum. The PPDU is generated by down-clocking an 802.11ac signal by a factor so that the bandwidth of the PPDU decreases down to one appropriate for use in a TVWS channel.

Claims

1. A method for wireless communication in a television broadcast frequency spectrum operational at a transmitter, the method comprising:

generating a Physical Layer Convergence Protocol Packet Data Unit (PPDU) having a preamble and a payload, wherein symbols of the PPDU each include 128 total (orthogonal frequency-division multiplexing) OFDM tones or 256 total OFDM tones, and the preamble includes

a signal (SIG) field symbol having 108 OFDM data tones if the symbols of the PPDU include 128 total OFDM tones or having 234 OFDM data tones if the symbols of the PPDU include 256 total OFDM tones, the SIG field symbol indicating at least one of an amount of data in the payload or a length of time that the PPDU will occupy the television broadcast frequency spectrum; and

transmitting the PPDU in the television broadcast frequency spectrum.

2. The method of claim 1, wherein generating the PPDU includes down-clocking a first signal having a first bandwidth by a factor to generate the PPDU having a second bandwidth, the first signal having a first signal preamble that includes a first short training field (STF) having two or more symbols, the first STF having a first STF time duration, and the preamble further includes:

a second STF having a second STF time duration, wherein the second STF time duration is less than the first STF time duration multiplied by the factor.

3. The method of claim 2, wherein the second STF time duration is equal to half of the first STF time duration multiplied by the factor.

4. The method of claim 2, wherein the second STF includes only one symbol.

5. The method of claim 2, wherein

if the symbols of the PPDU each include 128 total OFDM tones then the first bandwidth is 40 MHz, the second bandwidth is greater than or equal to four (4) MHz and less than or equal to eight (8) MHz, the first STF time duration is equal to eight (8) μ

sec, and the second STF time duration is greater than or equal to 20 μ

sec and less than or equal to 40 μ

sec, and

if the symbols of the PPDU each include 256 total OFDM tones then the first bandwidth is 80 MHz, the second bandwidth is greater than or equal to four (4) MHz and less than or equal to eight (8) MHz, the first STF time duration is eight (8) μ

sec, and the second STF time duration is greater than or equal to 40 μ

sec and less than or equal to 80 μ

sec.

6. The method of claim 1, wherein the preamble further includes:

a short training field (STF) symbol having every eighth tone or sixteenth tone populated if the symbols of the PPDU each include 128 total OFDM tones or having every sixteenth tone populated if the symbols of the PPDU each include 256 total OFDM tones.

7. The method of claim 1, wherein the preamble further includes:

a short training field (STF) symbol having a repetition interval greater than or equal to 2 microseconds (μ

s) and less than or equal to 4 μ

s if the symbols of the PPDU each include 128 total OFDM tones or having a repetition interval greater than or equal to 4 μ

s and less than or equal to 8 μ

s if the symbols of the PPDU each include 256 total OFDM tones.

8. The method of claim 1, wherein generating the PPDU includes down-clocking a first signal having a first bandwidth by a factor to generate the PPDU having a second bandwidth, the first signal having a first signal preamble that includes a first SIG field having at least one symbol, wherein the symbol of the first SIG field is limited to 48 OFDM data tones per 20 MHz sub-band of the first signal.

9. The method of claim 1, wherein generating the PPDU includes down-clocking a first signal having a first bandwidth by a factor to generate the PPDU having a second bandwidth, the first signal having a first signal preamble including at least ten (10) symbols, wherein the preamble of the PPDU has seven (7) symbols.

10. The method of claim 1, wherein generating the PPDU includes down-clocking a first signal having a first bandwidth by a factor to generate the PPDU having a second bandwidth, the first signal having a first signal preamble, the first signal preamble having a first signal preamble time duration, wherein a time duration of the preamble of the PPDU is less than 82% of the first signal preamble time duration multiplied by the factor.

11. The method of claim 1, wherein the SIG field symbol includes 54 bits of data if the symbols of the PPDU each include 128 total OFDM tones or 117 bits of data if the symbols of the PPDU each include 256 total OFDM tones.

12. The method of claim 1, wherein the SIG field symbol further indicates a bandwidth of the payload, a modulation and coding rate scheme of the payload, and a number of spatial streams of the payload.

13. The method of claim 1, wherein the SIG field symbol further indicates whether one or more symbols of the preamble or the payload are beamformed.

14. The method of claim 1, wherein the SIG field symbol is modulated using quadrature binary phase shift keying (QBPSK) to indicate whether one or more symbols of the preamble or the payload are beamformed.

15. The method of claim 1, wherein the SIG field symbol further indicates whether the payload is to be transmitted in a single user mode or a multi-user mode, and if the payload is to be transmitted in the multi-user mode the SIG field symbol further indicates a group identifier (ID) that identifies at least one intended receiver of the payload, and the preamble further includes:

a signal B (SIG-B) field symbol that indicates a modulation and coding rate scheme of the payload.

16. The method of claim 1, wherein the preamble further includes:

a beamformed signal (BF-SIG) field that indicates at least one of a group identifier (ID) that identifies at least one intended receiver of the payload, a number of spatial streams for the payload for each user of a plurality of users, and/or a modulation and coding rate scheme for the payload for each user of the plurality of users.

17. The method of claim 1, wherein the bandwidth of the PPDU is greater than or equal to 5 MHz and less than or equal to 6 MHz if the symbols of the PPDU each include 128 total OFDM tones, or the bandwidth of the PPDU is 8 MHz if the symbols of the PPDU each include 256 total OFDM tones.

18. The method of claim 1, wherein the television broadcast frequency spectrum is less than 1 GHz.

19. The method of claim 1, further comprising:

down-clocking a 40 MHz bandwidth signal by a factor greater than or equal to 5 and less than or equal to 10 to generate the symbols of the PPDU including 128 total OFDM tones; and

down-clocking an 80 MHz bandwidth signal by a factor greater than or equal to 10 and less than or equal to 20 to generate the symbols of the PPDU including 256 total OFDM tones.

20. The method of claim 19, wherein the 40 MHz and 80 MHz bandwidth signals are defined in accordance with the 802.11ac standard of the Institute of Electronics and Electrical Engineers (IEEE).

21. The method of claim 1, wherein each symbol of the preamble has a cyclic prefix duration greater than or equal to 4 μ

sec and less than or equal to 8 μ

sec if the symbols of the PPDU each include 128 total OFDM tones, or greater than or equal to 8 μ

sec and less than or equal to 16 μ

sec if the symbols of the PPDU each include 256 total OFDM tones.

22. The method of claim 1, wherein a symbol duration, including a cyclic prefix duration, of each preamble symbol of the PPDU is greater than or equal to 20 μ

sec and less than or equal to 40 μ

sec if the symbols of the PPDU each include 128 total OFDM tones, or greater than or equal to 40 μ

sec and less than or equal to 80 μ

sec if the symbols of the PPDU each include 256 total OFDM tones.

23. The method of claim 1, wherein generating the PPDU includes down-clocking a first signal having a first bandwidth by a factor to generate the PPDU having a second bandwidth, the first signal having a first signal preamble that includes two legacy short training field (STF) symbols, two legacy long training (LTF) field symbols, one first signal field symbol, two very high throughput (VHT) signal A field symbols, one VHT STF field symbol, at least one VHT LTF field symbol, and one first signal B field symbol, and wherein the preamble further includes:

a short training field (STF) symbol;

two long training field (LTF) symbols;

a beamforming signal (BF-SIG) field symbol for a multi-user, multiple-input multiple-output (MU-MIMO) mode or a single-user beamformed (SU-BF) mode;

a precoded short training (PC-STF) field symbol; and

at least one precoded long training (PC-LTF) field symbol.

24. A wireless transmitter apparatus configured for wireless communication in a television broadcast frequency spectrum, the apparatus comprising:

a processing circuit adapted to generate a Physical Layer Convergence Protocol Packet Data Unit (PPDU) having a preamble and a payload, wherein symbols of the PPDU each include 128 total (orthogonal frequency-division multiplexing) OFDM tones or 256 total OFDM tones, and the preamble includes

a signal (SIG) field symbol having 108 OFDM data tones if the symbols of the PPDU include 128 total OFDM tones or having 234 OFDM data tones if the symbols of the PPDU include 256 total OFDM tones, the SIG field symbol indicating at least one of an amount of data in the payload or a length of time that the PPDU will occupy the television broadcast frequency spectrum; and

a wireless transmitter communicatively coupled to the processing circuit and adapted to transmit the PPDU in the television broadcast frequency spectrum.

25. The wireless transmitter apparatus of claim 24, wherein the processing circuit is further adapted to down-clock a first signal having a first bandwidth by a factor to generate the PPDU having a second bandwidth, the first signal having a first signal preamble that includes a first short training field (STF) having two or more symbols, the first STF having a first STF time duration, and the preamble further includes:

a second STF having a second STF time duration, wherein the second STF time duration is less than the first STF time duration multiplied by the factor.

26. The wireless transmitter apparatus of claim 24, wherein the preamble further includes:

a short training field (STF) symbol having every eighth tone or sixteenth tone populated if the symbols of the PPDU each include 128 total OFDM tones or having every sixteenth tone populated if the symbols of the PPDU each include 256 total OFDM tones.

27. The wireless transmitter apparatus of claim 24, wherein the processing circuit is further adapted to down-clock a first signal having a first bandwidth by a factor to generate the PPDU having a second bandwidth, the first signal having a first signal preamble including at least ten (10) symbols, wherein the preamble of the PPDU has seven (7) symbols.

28. The wireless transmitter apparatus of claim 24, wherein the processing circuit is further adapted to down-clock a first signal having a first bandwidth by a factor to generate the PPDU having a second bandwidth, the first signal having a first signal preamble that includes two legacy short training field (STF) symbols, two legacy long training (LTF) field symbols, one first signal field symbol, two very high throughput (VHT) signal A field symbols, one VHT STF field symbol, at least one VHT LTF field symbol, and one first signal B field symbol, and wherein the preamble further includes:

a short training field (STF) symbol;

two long training field (LTF) symbols;

a beamforming signal (BF-SIG) field symbol for a multi-user, multiple-input multiple-output (MU-MIMO) mode or a single-user beamformed (SU-BF) mode;

a precoded short training (PC-STF) field symbol; and

at least one precoded long training (PC-LTF) field symbol.

29. A wireless transmitter apparatus configured for wireless communication in a television broadcast frequency spectrum, the apparatus comprising:

means for generating a Physical Layer Convergence Protocol Packet Data Unit (PPDU) having a preamble and a payload, wherein symbols of the PPDU each include 128 total (orthogonal frequency-division multiplexing) OFDM tones or 256 total OFDM tones, and the preamble includes

a signal (SIG) field symbol having 108 OFDM data tones if the symbols of the PPDU include 128 total OFDM tones or having 234 OFDM data tones if the symbols of the PPDU include 256 total OFDM tones, the SIG field symbol indicating at least one of an amount of data in the payload or a length of time that the PPDU will occupy the television broadcast frequency spectrum; and

means for transmitting the PPDU in the television broadcast frequency spectrum.

30. A non-transitory processor-readable medium having one or more instructions stored thereon for wireless communication in a television broadcast frequency spectrum, which when executed by at least one processor causes the processor to:

generate a Physical Layer Convergence Protocol Packet Data Unit (PPDU) having a preamble and a payload, wherein symbols of the PPDU each include 128 total (orthogonal frequency-division multiplexing) OFDM tones or 256 total OFDM tones, and the preamble includes

a signal (SIG) field symbol having 108 OFDM data tones if the symbols of the PPDU include 128 total OFDM tones or having 234 OFDM data tones if the symbols of the PPDU include 256 total OFDM tones, the SIG field symbol indicating at least one of an amount of data in the payload or a length of time that the PPDU will occupy the television broadcast frequency spectrum; and

transmit the PPDU in the television broadcast frequency spectrum.

31. A method for wireless communication in a television broadcast frequency spectrum operational at a receiver, the method comprising:

receiving in the television broadcast frequency spectrum a Physical Layer Convergence Protocol Packet Data Unit (PPDU) having a preamble and a payload, wherein symbols of the PPDU each include 128 total (orthogonal frequency-division multiplexing) OFDM tones or 256 total OFDM tones, and the preamble includes

a signal (SIG) field symbol having 108 OFDM data tones if the symbols of the PPDU include 128 total OFDM tones or having 234 OFDM data tones if the symbols of the PPDU include 256 total OFDM tones, the SIG field symbol indicating at least one of an amount of data in the payload or a length of time that the PPDU will occupy the television broadcast frequency spectrum.

32. The method of claim 31, wherein the preamble further includes:

a short training field (STF) symbol having every eighth tone populated if the symbols of the PPDU each include 128 total OFDM tones or having every sixteenth tone populated if the symbols of the PPDU each include 256 total OFDM tones.

33. The method of claim 31, wherein the preamble further includes:

a short training field (STF) symbol having a repetition interval greater than or equal to 2 microseconds (μ

s) and less than or equal to 4 μ

s if the symbols of the PPDU each include 128 total OFDM tones or having a repetition interval greater than or equal to 4 μ

s and less than or equal to 8 μ

s if the symbols of the PPDU each include 256 total OFDM tones.

34. The method of claim 31, wherein the SIG field symbol includes 54 bits of data if the symbols of the PPDU each include 128 total OFDM tones or 117 bits of data if the symbols of the PPDU each include 256 total OFDM tones.

35. The method of claim 31, wherein the SIG field symbol further indicates a bandwidth of the payload, a modulation and coding rate scheme of the payload, and a number of spatial streams of the payload.

36. The method of claim 31, wherein the SIG field symbol further indicates whether one or more symbols of the preamble or the payload are beamformed.

37. The method of claim 31, wherein the SIG field symbol is modulated using quadrature binary phase shift keying (QBPSK) to indicate whether one or more symbols of the preamble or the payload are beamformed.

38. The method of claim 31, wherein the SIG field symbol further indicates whether the PPDU is a single user PPDU or a multi-user PPDU, and if the PPDU is a multi-user PPDU the SIG field symbol further indicates a group identifier (ID) that identifies at least one intended receiver of the payload, and the preamble further includes:

a signal B (SIG-B) field symbol that indicates a modulation and coding rate scheme of the payload.

39. The method of claim 31, wherein the preamble further includes:

a beamformed signal (BF-SIG) field that indicates at least one of a group identifier (ID) that identifies at least one intended receiver of the payload, a number of spatial streams for the payload for each user of a plurality of users, and/or a modulation and coding rate scheme for the payload for each user of the plurality of users.

40. The method of claim 31, wherein the bandwidth of the PPDU is greater than or equal to 5 MHz and less than or equal to 6 MHz if the symbols of the PPDU each include 128 total OFDM tones, or the bandwidth of the PPDU is 8 MHz if the symbols of the PPDU each include 256 total OFDM tones.

41. The method of claim 31, wherein the television broadcast frequency spectrum is less than 1 GHz.

42. The method of claim 31, wherein each symbol of the preamble has a cyclic prefix duration greater than or equal to 4 μ

sec and less than or equal to 8 μ

sec if the symbols of the PPDU each include 128 total OFDM tones, or greater than or equal to 8 μ

sec and less than or equal to 16 μ

sec if the symbols of the PPDU each include 256 total OFDM tones.

43. The method of claim 31, wherein a symbol duration, including a cyclic prefix duration, of each preamble symbol of the PPDU is greater than or equal to 20 μ

sec and less than or equal to 40 μ

sec if the symbols of the PPDU each include 128 total OFDM tones, or greater than or equal to 40 μ

sec and less than or equal to 80 μ

sec if the symbols of the PPDU each include 256 total OFDM tones.

44. The method of claim 31, wherein the preamble further includes:

a short training field (STF) symbol;

two long training field (LTF) symbols;

a beamforming signal (BF-SIG) field symbol for a multi-user, multiple-input multiple-output (MU-MIMO) mode or a single-user beamformed (SU-BF) mode;

a precoded short training (PC-STF) field symbol; and

at least one precoded long training (PC-LTF) field symbol.

45. The method of claim 31, wherein receiving the PPDU includes:

applying a down-clocking factor to a clock of the receiver, the down-clocking factor associated with a bandwidth of the received PPDU.

46. A wireless receiver apparatus for wireless communication in a television broadcast frequency spectrum, the apparatus comprising:

a wireless receiver adapted to receive in the television broadcast frequency spectrum a Physical Layer Convergence Protocol Packet Data Unit (PPDU) having a preamble and a payload, wherein symbols of the PPDU each include 128 total (orthogonal frequency-division multiplexing) OFDM tones or 256 total OFDM tones, and the preamble includes

a signal (SIG) field symbol having 108 OFDM data tones if the symbols of the PPDU include 128 total OFDM tones or having 234 OFDM data tones if the symbols of the PPDU include 256 total OFDM tones, the SIG field symbol indicating at least one of an amount of data in the payload or a length of time that the PPDU will occupy the television broadcast frequency spectrum; and

a processing circuit communicatively coupled to the wireless receiver and adapted to process the PPDU received.

47. The wireless receiver apparatus of claim 46, wherein the processing circuit is further adapted to apply a down-clocking factor to a clock of the wireless receiver apparatus, the down-clocking factor associated with a bandwidth of the received PPDU.

48. The wireless receiver apparatus of claim 46, wherein the preamble further includes:

a short training field (STF) symbol having every eighth tone populated if the symbols of the PPDU each include 128 total OFDM tones or having every sixteenth tone populated if the symbols of the PPDU each include 256 total OFDM tones.

49. The wireless receiver apparatus of claim 46, wherein the SIG field symbol includes 54 bits of data if the symbols of the PPDU each include 128 total OFDM tones or 117 bits of data if the symbols of the PPDU each include 256 total OFDM tones.

50. The wireless receiver apparatus of claim 46, wherein the SIG field symbol further indicates whether the PPDU is a single user PPDU or a multi-user PPDU, and if the PPDU is a multi-user PPDU the SIG field symbol further indicates a group identifier (ID) that identifies at least one intended receiver of the payload, and the preamble further includes:

a signal B (SIG-B) field symbol that indicates a modulation and coding rate scheme of the payload.

51. The wireless receiver apparatus of claim 46, wherein the preamble further includes:

a beamformed signal (BF-SIG) field that indicates at least one of a group identifier (ID) that identifies at least one intended receiver of the payload, a number of spatial streams for the payload for each user of a plurality of users, and/or a modulation and coding rate scheme for the payload for each user of the plurality of users.

52. The wireless receiver apparatus of claim 46, wherein the bandwidth of the PPDU is greater than or equal to 5 MHz and less than or equal to 6 MHz if the symbols of the PPDU each include 128 total OFDM tones, or the bandwidth of the PPDU is 8 MHz if the symbols of the PPDU each include 256 total OFDM tones.

53. The wireless receiver apparatus of claim 46, wherein each symbol of the preamble has a cyclic prefix duration greater than or equal to 4 μ

sec and less than or equal to 8 μ

sec if the symbols of the PPDU each include 128 total OFDM tones, or greater than or equal to 8 μ

sec and less than or equal to 16 μ

sec if the symbols of the PPDU each include 256 total OFDM tones.

54. The wireless receiver apparatus of claim 46, wherein the preamble further includes:

a short training field (STF) symbol;

two long training field (LTF) symbols;

a beamforming signal (BF-SIG) field symbol for a multi-user, multiple-input multiple-output (MU-MIMO) mode or a single-user beamformed (SU-BF) mode;

a precoded short training (PC-STF) field symbol; and

at least one precoded long training (PC-LTF) field symbol.

55. A wireless receiver apparatus for wireless communication in a television broadcast frequency spectrum, the apparatus comprising:

means for receiving in the television broadcast frequency spectrum a Physical Layer Convergence Protocol Packet Data Unit (PPDU) having a preamble and a payload, wherein symbols of the PPDU each include 128 total (orthogonal frequency-division multiplexing) OFDM tones or 256 total OFDM tones, and the preamble includes

a signal (SIG) field symbol having 108 OFDM data tones if the symbols of the PPDU include 128 total OFDM tones or having 234 OFDM data tones if the symbols of the PPDU include 256 total OFDM tones, the SIG field symbol indicating at least one of an amount of data in the payload or a length of time that the PPDU will occupy the television broadcast frequency spectrum.

56. A non-transitory processor-readable medium having one or more instructions stored thereon for wireless communication in a television broadcast frequency spectrum, which when executed by at least one processor causes the processor to:

receive in the television broadcast frequency spectrum a Physical Layer Convergence Protocol Packet Data Unit (PPDU) having a preamble and a payload, wherein symbols of the PPDU each include 128 total (orthogonal frequency-division multiplexing) OFDM tones or 256 total OFDM tones, and the preamble includes

a signal (SIG) field symbol having 108 OFDM data tones if the symbols of the PPDU include 128 total OFDM tones or having 234 OFDM data tones if the symbols of the PPDU include 256 total OFDM tones, the SIG field symbol indicating at least one of an amount of data in the payload or a length of time that the PPDU will occupy the television broadcast frequency spectrum.