APPARATUS AND METHODS FOR LONG AND SHORT TRAINING SEQUENCES FOR A FAST FOURIER TRANSFORM

• US 20130230120A1
• Filed: 08/28/2012
• Published: 09/05/2013
• Est. Priority Date: 08/29/2011
• Status: Abandoned Application

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Yang, Lin, Van Nee, Didier Johannes Richard, Taghavi Nasrabadi, Mohammad Hossein, Vermani, Sameer, Sampath, Hemanth
• Application Number:
  US13/596,931
• Publication Number:
  US 20130230120A1
• Time in Patent Office: Days
• US Class Current: 375/295
• CPC Class Codes: H04L 1/001 applied to control information
• CPC Class Codes: H04L 27/2613 Structure of the reference signals
• CPC Class Codes: H04L 27/26132 using repetition
• CPC Class Codes: H04L 27/262 Reduction thereof by selection of pilot symbols
• CPC Class Codes: H04L 27/2666 Acquisition of further OFDM parameters, e.g. bandwidth, subcarrier spacing, or guard interval length

Abstract

Apparatus and methods for communicating and applying training sequences are described herein. For example, provided is a method for generating a short training field (STF) sequence comprising thirty two values or less. The STF sequence can include a first subset of values including zero and non-zero values. The non-zero values can be located at indices of the first subset that are at least a multiple of two, and can be a multiple of four. The STF sequence includes a second subset of zero values that can include all values not included within the first subset. The method further includes transmitting a data unit comprising the STF sequence over a wireless channel. In another example, a method is provided that includes generating a long training field (LTF) sequence comprising thirty two values or less, and transmitting a data unit comprising the LTF sequence over a wireless channel.

Claims

1. A method for wireless communication, comprising:

generating one or more short training field (STF) sequences comprising thirty two values or less, wherein the one or more STF sequences comprises a first subset of values comprising values of zero and non-zero values, wherein the non-zero values are located at indices of the first subset that are at least a multiple of two, wherein the one or more STF sequences comprises a second subset of zero values, and wherein the second subset of zero values comprises all values not included within the first subset; and

transmitting a data unit comprising the one or more STF sequences over a wireless channel.

2. The method of claim 1, wherein the non-zero values comprises either a value of one plus the imaginary unit multiplied by the square root of one-half (+√

{square root over (1/2)}(1+j)) or a value of one plus the imaginary unit multiplied by the negative square root of one-half (−

√

{square root over (1/2)}(1+j)).

3. The method of claim 1, wherein the STF sequence is characterized by a peak-to-average power ratio having a value less than 4.5 db.

4. The method of claim 1, wherein the STF sequence is characterized by a peak-to-average power ratio having a value less than 2.25 db.

5. The method of claim 1, wherein the non-zero values are located at indices of the first subset that are a multiple of four.

6. The method of claim 5, wherein the first subset of values corresponds to indices in a range from −

13 to +13, and wherein the first subset of value comprises values of a square root of one half multiplied by 0, 1+j, 0, 0, 0, −

1−

j, 0, 0, 0, 1+j, 0, 0, 0, 0, 0, 0, 0, −

1−

j, 0, 0, 0, −

1−

j, 0, 0, 0, −

1−

j, and 0.

7. The method of claim 6, wherein the values of the STF sequence comprise values corresponding to five guard subcarriers, one DC subcarrier, two pilot subcarriers, and twenty-four data subcarriers, and wherein the first three values of the STF sequence correspond to three guard subcarriers, and the last two values of the STF sequence correspond to two guard subcarriers, and wherein a value corresponding to an index of zero corresponds to the DC subcarrier.

8. The method of claim 5, wherein the first subset of values corresponds to indices in a range from −

12 to +12, and wherein the first subset of value comprises values of a square root of one half multiplied by 1+j, 0, 0, 0, −

1−

j, 0, 0, 0, 1+j, 0, 0, 0, 0, 0, 0, 0, −

1−

j, 0, 0, 0, −

1−

j, 0, 0, 0, and −

1−

j.

9. The method of claim 8, wherein the values of the STF sequence comprise values corresponding to seven guard subcarriers, one DC subcarrier, two pilot subcarriers, and twenty-two data subcarriers, and wherein the first four values of the STF sequence correspond to four guard subcarriers, and the last three values of the STF sequence correspond to two three subcarriers, and wherein a value corresponding to an index of zero corresponds to the DC subcarrier.

10. The method of claim 1, wherein the generating one or more short training field (STF) sequences comprises generating one or more STF sequences for use with an extended range mode.

11. The method of claim 10, wherein the first subset of values corresponds to indices in a range from −

13 to +13, and wherein the first subset of values comprises values of the square root of one half multiplied by 0, 1+j, 0, 1+j, 0, 1+j, 0, −

1−

j, 0, −

1−

j, 0, −

1−

j, 0, 0, 0, −

1−

j, 0, 1+j, 0, −

1−

j, 0, −

1−

j, 0, 1+j, 0, −

1−

j, and 0.

12. The method of claim 11, wherein the values of the STF sequence comprise values corresponding to five guard subcarriers, one DC subcarrier, two pilot subcarriers, and twenty-four data subcarriers, and wherein the first three values of the STF sequence correspond to three guard subcarriers, and the last two values of the STF sequence correspond to two guard subcarriers, and wherein a value corresponding to an index of zero corresponds to the DC subcarrier.

13. The method of claim 10, wherein the first subset of values corresponds to indices in a range from −

12 to +12, and wherein the first subset of values comprises values of the square root of one half multiplied by 1+j, 0, 1+j, 0, 1+j, 0, −

1−

j, 0, −

1−

j, 0, −

1−

j, 0, 0, 0, −

1−

j, 0, 1+j, 0, −

1−

j, 0, −

1−

j, 0, 1+j, 0, and −

1−

j.

14. The method of claim 13, wherein the values of the STF sequence comprise values corresponding to seven guard subcarriers, one DC subcarrier, two pilot subcarriers, and twenty-two data subcarriers, and wherein the first three values of the STF sequence correspond to three guard subcarriers, and the last two values of the STF sequence correspond to two guard subcarriers, and wherein a value corresponding to an index of zero corresponds to the DC subcarrier.

15. The method of claim 1, wherein each value in the one or more STF sequences corresponds to one of a guard subcarrier, a direct current subcarrier, a data subcarrier, and a pilot subcarrier of a signal.

16. The method of claim 15, wherein the first subset comprises values corresponding to the direct current subcarrier, the data subcarrier, and the pilot subcarrier, wherein the first subset of values corresponds to indices in a range from a negative number to a positive number, and wherein the direct current subcarrier has an index of zero.

17. The method of claim 1, wherein the second subset comprises a set of guard values each comprising a value of zero.

18. The method of claim 1, wherein the one or more STF sequences are configured to be used with a power boosting scheme.

19. A wireless communication apparatus, comprising:

a processor configured to generate one or more short training field (STF) sequences comprising thirty two values or less, wherein the one or more STF sequences comprises a first subset of values comprising values of zero and non-zero values, wherein the non-zero values are located at indices of the first subset that are at least a multiple of two, wherein the one or more STF sequences comprises a second subset of zero values, and wherein the second subset of zero values comprises all values not included within the first subset; and

a transmitter configured to transmit a data unit comprising the one or more STF sequences over a wireless channel.

20. A wireless communication apparatus, comprising:

means for generating one or more short training field (STF) sequences comprising thirty two values or less, wherein the one or more STF sequences comprises a first subset of values comprising values of zero and non-zero values, wherein the non-zero values are located at indices of the first subset that are at least a multiple of two, wherein the one or more STF sequences comprises a second subset of zero values, and wherein the second subset of zero values comprises all values not included within the first subset; and

means for transmitting a data unit comprising the one or more STF sequences over a wireless channel.

21. A method for wireless communication, comprising:

generating one or more long training field (LTF) sequences comprising thirty two values or less, wherein each of the values of the one or more LTF sequences correspond to one of a guard subcarrier, a direct current subcarrier, a pilot subcarrier, and a data subcarrier, wherein each of the values corresponding to the pilot subcarrier and the data subcarrier comprise a value of either one or negative one, and wherein each of the values corresponding to the guard subcarrier and the direct current subcarrier comprises a value of zero; and

transmitting a data unit comprising the one or more LTF sequences over a wireless channel.

22. The method of claim 21, wherein the LTF sequence is characterized by a peak to average ratio that has a value less than 2 db.

23. The method of claim 21, wherein the values corresponding to the direct current subcarrier, the pilot subcarrier, and the data subcarrier corresponds to indices in a range from −

13 to +13, and wherein the values corresponding to the direct current subcarrier, the pilot subcarrier, and the data subcarrier comprise a subset of values comprising 1, −

1, 1, 1, −

1, 1, 1, −

1, 1, 1, 1, −

1, 1, 0, −

1, −

1, −

1, 1, −

1, −

1, −

1, 1, 1, 1, −

1, −

1, and −

1.

24. The method of claim 23, wherein the values of the LTF sequence values correspond to five guard subcarriers, one DC subcarrier, two pilot subcarriers, and twenty-four data subcarriers, and wherein the first three values of the LTF sequence correspond to three guard subcarriers, and the last two values of the LTF sequence correspond to two guard subcarriers, and wherein a value corresponding to an index of zero corresponds to the DC subcarrier

25. The method of claim 21, wherein the values corresponding to the direct current subcarrier, the pilot subcarrier, and the data subcarrier corresponds to indices in a range from −

12 to +12, and wherein the values corresponding to the direct current subcarrier, the pilot subcarrier, and the data subcarrier comprise a subset of values comprising 1, 1, −

1, −

1, −

1, −

1, 1, 1, −

1, 1, 1, −

1, 0, 1, 1, 1, −

1, 1, 1, −

1, 1, −

1, 1, −

1, and 1.

26. The method of claim 25, wherein the values of the LTF sequence values correspond to seven guard subcarriers, one DC subcarrier, two pilot subcarriers, and twenty-two data subcarriers, and wherein the first four values of the LTF sequence correspond to four guard subcarriers, and the last three values of the LTF sequence correspond to three guard subcarriers, and wherein a value corresponding to an index of zero corresponds to the DC subcarrier

27. The method of claim 21, wherein the generating one or more LTF sequences comprises generating one or more LTF sequences for use with a mode wherein values corresponding to pilot subcarriers are multiplied by a first value, and wherein values corresponding to data subcarriers are multiplied by a second value, the first value being different than the second value.

28. The method of claim 27, wherein the values corresponding to the direct current subcarrier, the pilot subcarrier, and the data subcarrier corresponds to indices in a range from −

13 to +13, and wherein the values corresponding to the pilot subcarriers have indices of −

7 and 7, and wherein the values corresponding to the direct current subcarrier, the pilot subcarriers, and the data subcarrier comprise a subset of values comprising 1, 1, −

1, 1, 1, −

1, 1, 1, −

1, −

1, −

1, −

1, −

1, 0, −

1, 1, −

1, 1, −

1, −

1, −

1, 1, 1, −

1, −

1, −

1, and 1.

29. The method of claim 28, wherein the values of the LTF sequence values corresponding to five guard subcarriers, one DC subcarrier, two pilot subcarriers, and twenty-four data subcarriers, and wherein the first three values of the LTF sequence correspond to three guard subcarriers, and the last two values of the LTF sequence correspond to two guard subcarriers, and wherein a value corresponding to an index of zero corresponds to the DC subcarrier.

30. The method of claim 27, wherein the values corresponding to the direct current subcarrier, the pilot subcarrier, and the data subcarrier corresponds to indices in a range from −

12 to +12, and wherein the values corresponding to the pilot subcarriers have indices of −

7 and +7, and wherein the values corresponding to the direct current subcarrier, the pilot subcarriers, and the data subcarrier comprise a subset of values comprising 1, 1, 1, 1, 1, 1, −

1, 1, 1, 1, −

1, −

1, 0, −

1, 1, 1, −

1, 1, 1, −

1, −

1, 1, −

1, 1, and −

1.

31. The method of claim 30, wherein the values of the LTF sequence values corresponding to seven guard subcarriers, one DC subcarrier, two pilot subcarriers, and twenty-two data subcarriers, and wherein the first four values of the LTF sequence correspond to four guard subcarriers, and the last three values of the LTF sequence correspond to three guard subcarriers, and wherein a value corresponding to an index of zero corresponds to the DC subcarrier.

32. The method of claim 21, wherein the one or more LTF sequences are configured to be substantially orthogonal to each halve of an additional LTF sequence comprising sixty four values, wherein the one or more LTF sequences correspond to a first channel and the additional LTF sequence corresponds to a second channel.

33. The method of claim 32, wherein the values corresponding to the direct current subcarrier, the pilot subcarrier, and the data subcarrier corresponds to indices in a range from −

13 to +13, and wherein the values corresponding to the direct current subcarrier, the pilot subcarrier, and the data subcarrier comprise a subset of values comprising 1, −

1, 1, 1, −

1, 1, 1, −

1, 1, 1, 1, −

1, 1, 0, −

1, −

1, −

1, 1, −

1, −

1, −

1, 1, 1, 1, −

1, −

1, and −

1.

34. The method of claim 32, wherein the values corresponding to the direct current subcarrier, the pilot subcarrier, and the data subcarrier corresponds to indices in a range from −

12 to +12, and wherein the values corresponding to the direct current subcarrier, the pilot subcarrier, and the data subcarrier comprise a subset of values comprising 1, 1, −

1, 1, −

1, 1, 1, 1, 1, −

1, −

1, 1, 0, 1, 1, 1, 1, 1, −

1, −

1, 1, −

1, −

1, −

1, and 1.

35. The method of claim 32, wherein the values comprise 0, 0, 0, 1, −

1, −

1, 1, −

1, 1, 1, −

1, 1, −

1, −

1, −

1, −

1, 0, −

1, −

1, −

1, 1, −

1, −

1, −

1, 1, −

1, 1, 1, 1, −

1, 0, and 0.

36. The method of claim 32, wherein the values comprise 0, 0, 0, 1, 1, −

1, −

1, 1, 1, 1, −

1, −

1, 1, 1, −

1, 1, 0, −

1, 1, 1, −

1, 1, −

1, −

1, −

1, 1, 1, 1, 1, 1, 0, and 0.

37. The method of claim 21, wherein a orthogonality metric of one of the one or more LTF sequences and either half of an additional LTF sequence comprising sixty four values is substantially equivalent to zero, wherein the one or more LTF sequences correspond to a first channel and the additional LTF sequence corresponds to a second channel.

38. The method of claim 21, wherein the one or more LTF sequences comprise two LTF sequences forming a part of a preamble of the data unit for use with communicating on a first channel, wherein the two TLF sequences span two symbols of the preamble.

39. The method of claim 38, wherein the two symbols are power boosted by 2 dB to 4 dB.

40. The method of claim 39, wherein the two symbols are power boosted for transmissions where data for the data unit is encoded based on a 2×

repetition of BPSK rate one-half.

41. The method of claim 38 wherein the first channel corresponds to a 1 MHz channel.

64. The method of claim 21, wherein the LTF sequence is characterized by a peak to average ratio that has a value less than 2 db.

42. A wireless communication apparatus, comprising:

a processor configured to generate one or more long training field (LTF) sequences comprising thirty two values or less, wherein each of the values of the one or more LTF sequences correspond to one of a guard subcarrier, a direct current subcarrier, a pilot subcarrier, and a data subcarrier, wherein each of the values corresponding to the pilot subcarrier and the data subcarrier comprise a value of either one or negative one, and wherein each of the values corresponding to the guard subcarrier and the direct current subcarrier comprises a value of 0; and

a transmitter configured to transmit a data unit comprising the one or more LTF sequences over a wireless channel.

43. A wireless communication apparatus, comprising:

means for generating one or more long training field (LTF) sequences comprising thirty two values or less, wherein each of the values of the one or more LTF sequences correspond to one of a guard subcarrier, a direct current subcarrier, a pilot subcarrier, and a data subcarrier, wherein each of the values corresponding to the pilot subcarrier and the data subcarrier comprise a value of either one or negative one, and wherein each of the values corresponding to the guard subcarrier and the direct current subcarrier comprises a value of 0; and

means for transmitting a data unit comprising the one or more LTF sequences over a wireless channel.

44. A method for wireless communication, comprising:

receiving a data unit comprising one or more short training field (STF) sequences comprising thirty two values or less, wherein the one or more STF sequences comprises a first subset of values comprising values of zero and non-zero values, wherein the non-zero values are located at indices of the first subset that are at least a multiple of two, wherein the one or more STF sequences comprises a second subset of zero values, and wherein the second subset of zero values comprises all values not included within the first subset; and

decoding one or more data symbols based at least in part on the one or more STF sequences.

45. The method of claim 44, wherein the non-zero values comprises either a value of one plus the imaginary unit multiplied by the square root of one-half (+√

{square root over (1/2)}/(1+j)) or a value of one plus the imaginary unit multiplied by the negative square root of one-half (−

√

{square root over (1/2)}(1+j)).

46. The method of claim 44, wherein the STF sequence is characterized by a peak-to-average power ratio having a value less than 4.5 db.

47. The method of claim 44, wherein the STF sequence is characterized by a peak-to-average power ratio having a value less than 2.25 db.

48. The method of claim 44, wherein the non-zero values are located at indices of the first subset that are a multiple of four.

49. The method of claim 48, wherein the first subset of values corresponds to indices in a range from −

13 to +13, and wherein the first subset of value comprises values of a square root of one half multiplied by 0, 1+j, 0, 0, 0, −

1−

j, 0, 0, 0, 1+j, 0, 0, 0, 0, 0, 0, 0, −

1−

j, 0, 0, 0, −

1−

j, 0, 0, 0, −

1−

j, and 0.

50. The method of claim 49, wherein the values of the STF sequence comprise values corresponding to five guard subcarriers, one DC subcarrier, two pilot subcarriers, and twenty-four data subcarriers, and wherein the first three values of the STF sequence correspond to three guard subcarriers, and the last two values of the STF sequence correspond to two guard subcarriers, and wherein a value corresponding to an index of zero corresponds to the DC subcarrier.

51. The method of claim 48, wherein the first subset of values corresponds to indices in a range from −

12 to +12, and wherein the first subset of value comprises values of a square root of one half multiplied by 1+j, 0, 0, 0, −

1−

j, 0, 0, 0, 1+j, 0, 0, 0, 0, 0, 0, 0, −

1−

j, 0, 0, 0, −

1−

j, 0, 0, 0, and −

1−

j.

52. The method of claim 51, wherein the values of the STF sequence comprise values corresponding to seven guard subcarriers, one DC subcarrier, two pilot subcarriers, and twenty-two data subcarriers, and wherein the first four values of the STF sequence correspond to four guard subcarriers, and the last three values of the STF sequence correspond to two three subcarriers, and wherein a value corresponding to an index of zero corresponds to the DC subcarrier.

53. The method of claim 44, wherein the receiving one or more short training field (STF) sequences comprises receiving one or more STF sequences for use with an extended range mode.

54. The method of claim 53, wherein the first subset of values corresponds to indices in a range from −

13 to +13, and wherein the first subset of values comprises values of the square root of one half multiplied by 0, 1+j, 0, 1+j, 0, 1+j, 0, −

1−

j, 0, −

1−

j, 0, −

1−

j, 0, 0, 0, −

1−

j, 0, 1+j, 0, −

1−

j, 0, −

1−

j, 0, 1+j, 0, −

1−

j, and 0.

55. The method of claim 54, wherein the values of the STF sequence comprise values corresponding to five guard subcarriers, one DC subcarrier, two pilot subcarriers, and twenty-four data subcarriers, and wherein the first three values of the STF sequence correspond to three guard subcarriers, and the last two values of the STF sequence correspond to two guard subcarriers, and wherein a value corresponding to an index of zero corresponds to the DC subcarrier.

56. The method of claim 53, wherein the first subset of values corresponds to indices in a range from −

12 to +12, and wherein the first subset of values comprises values of the square root of one half multiplied by 1+j, 0, 1+j, 0, 1+j, 0, −

1−

j, 0, −

1−

j, 0, −

1−

j, 0, 0, 0, −

1−

j, 0, 1+j, 0, −

1−

j, 0, −

1−

j, 0, 1+j, 0, and −

1−

j.

57. The method of claim 56, wherein the values of the STF sequence comprise values corresponding to seven guard subcarriers, one DC subcarrier, two pilot subcarriers, and twenty-two data subcarriers, and wherein the first three values of the STF sequence correspond to three guard subcarriers, and the last two values of the STF sequence correspond to two guard subcarriers, and wherein a value corresponding to an index of zero corresponds to the DC subcarrier.

58. The method of claim 44, wherein each value in the one or more STF sequences corresponds to one of a guard subcarrier, a direct current subcarrier, a data subcarrier, and a pilot subcarrier of a signal.

59. The method of claim 58, wherein the first subset comprises values corresponding to the direct current subcarrier, the data subcarrier, and the pilot subcarrier, wherein the first subset of values corresponds to indices in a range from a negative number to a positive number, and wherein the direct current subcarrier has an index of zero.

60. The method of claim 44, wherein the second subset comprises a set of guard values each comprising a value of zero.

61. The method of claim 44, wherein the one or more STF sequences are configured to be used with a power boosting scheme

62. A wireless communication apparatus, comprising:

a receiver configured to receive a data unit comprising one or more short training field (STF) sequences comprising thirty two values or less, wherein the one or more STF sequences comprises a first subset of values comprising values of zero and non-zero values, wherein the non-zero values are located at indices of the first subset that are at least a multiple of two, wherein the one or more STF sequences comprises a second subset of zero values, and wherein the second subset of zero values comprises all values not included within the first subset; and

a processor configured to decode one or more data symbols based at least in part on the one or more STF sequences.

63. A wireless communication apparatus, comprising:

means for receiving a data unit comprising one or more short training field (STF) sequences comprising thirty two values or less, wherein the one or more STF sequences comprises a first subset of values comprising values of zero and non-zero values, wherein the non-zero values are located at indices of the first subset that are at least a multiple of two, wherein the one or more STF sequences comprises a second subset of zero values, and wherein the second subset of zero values comprises all values not included within the first subset; and

means for decoding one or more data symbols based at least in part on the one or more STF sequences.

65. A method for wireless communication, comprising:

receiving one or more long training field (LTF) sequences comprising thirty two values or less, wherein each of the values of the one or more LTF sequences correspond to one of a guard subcarrier, a direct current subcarrier, a pilot subcarrier, and a data subcarrier, wherein each of the values corresponding to the pilot subcarrier and the data subcarrier comprise a value of either one or negative one, and wherein each of the values corresponding to the guard subcarrier and the direct current subcarrier comprises a value of zero; and

decoding one or more data symbols based at least in part on the one or more LTF sequences.

66. The method of claim 65, wherein the LTF sequence is characterized by a peak to average ratio that has a value less than 2 db.

67. The method of claim 65, wherein the values corresponding to the direct current subcarrier, the pilot subcarrier, and the data subcarrier corresponds to indices in a range from −

13 to +13, and wherein the values corresponding to the direct current subcarrier, the pilot subcarrier, and the data subcarrier comprise a subset of values comprising 1, −

1, 1, 1, −

1, 1, 1, −

1, 1, 1, 1, −

1, 1, 0, −

1, −

1, −

1, 1, −

1, −

1, −

1, 1, 1, 1, −

1, −

1, and −

1.

68. The method of claim 67, wherein the values of the LTF sequence values correspond to five guard subcarriers, one DC subcarrier, two pilot subcarriers, and twenty-four data subcarriers, and wherein the first three values of the LTF sequence correspond to three guard subcarriers, and the last two values of the LTF sequence correspond to two guard subcarriers, and wherein a value corresponding to an index of zero corresponds to the DC subcarrier

69. The method of claim 65, wherein the values corresponding to the direct current subcarrier, the pilot subcarrier, and the data subcarrier corresponds to indices in a range from −

12 to +12, and wherein the values corresponding to the direct current subcarrier, the pilot subcarrier, and the data subcarrier comprise a subset of values comprising 1, 1, −

1, −

1, −

1, −

1, 1, 1, −

1, 1, 1, −

1, 0, 1, 1, 1, −

1, 1, 1, −

1, 1, −

1, 1, −

1, and 1.

70. The method of claim 69, wherein the values of the LTF sequence values correspond to seven guard subcarriers, one DC subcarrier, two pilot subcarriers, and twenty-two data subcarriers, and wherein the first four values of the LTF sequence correspond to four guard subcarriers, and the last three values of the LTF sequence correspond to three guard subcarriers, and wherein a value corresponding to an index of zero corresponds to the DC subcarrier

71. The method of claim 65, wherein generating one or more LTF sequences comprises generating one or more LTF sequences for use with a mode wherein values corresponding to pilot subcarriers are multiplied by a first value, and wherein values corresponding to data subcarriers are multiplied by a second value, the first value being different than the second value.

72. The method of claim 71, wherein the values corresponding to the direct current subcarrier, the pilot subcarrier, and the data subcarrier corresponds to indices in a range from −

13 to +13, and wherein the values corresponding to the pilot subcarriers have indices of −

7 and 7, and wherein the values corresponding to the direct current subcarrier, the pilot subcarriers, and the data subcarrier comprise a subset of values comprising 1, 1, −

1, 1, 1, −

1, 1, 1, −

1, −

1, −

1, −

1, −

1, 0, −

1, 1, −

1, 1, −

1, −

1, −

1, 1, 1, −

1, −

1, −

1, and 1.

73. The method of claim 72, wherein the values of the LTF sequence values corresponding to five guard subcarriers, one DC subcarrier, two pilot subcarriers, and twenty-four data subcarriers, and wherein the first three values of the LTF sequence correspond to three guard subcarriers, and the last two values of the LTF sequence correspond to two guard subcarriers, and wherein a value corresponding to an index of zero corresponds to the DC subcarrier.

74. The method of claim 71, wherein the values corresponding to the direct current subcarrier, the pilot subcarrier, and the data subcarrier corresponds to indices in a range from −

12 to +12, and wherein the values corresponding to the pilot subcarriers have indices of −

7 and +7, and wherein the values corresponding to the direct current subcarrier, the pilot subcarriers, and the data subcarrier comprise a subset of values comprising 1, 1, 1, 1, 1, 1, −

1, 1, 1, 1, −

1, −

1, 0, −

1, 1, 1, −

1, 1, 1, −

1, −

1, 1, −

1, 1, and −

1.

75. The method of claim 74, wherein the values of the LTF sequence values corresponding to seven guard subcarriers, one DC subcarrier, two pilot subcarriers, and twenty-two data subcarriers, and wherein the first four values of the LTF sequence correspond to four guard subcarriers, and the last three values of the LTF sequence correspond to three guard subcarriers, and wherein a value corresponding to an index of zero corresponds to the DC subcarrier.

76. The method of claim 65, wherein the one or more LTF sequences are configured to be substantially orthogonal to each halve of an additional LTF sequence comprising sixty four values, wherein the one or more LTF sequences correspond to a first channel and the additional LTF sequence corresponds to a second channel.

77. The method of claim 76, wherein the values corresponding to the direct current subcarrier, the pilot subcarrier, and the data subcarrier corresponds to indices in a range from −

13 to +13, and wherein the values corresponding to the direct current subcarrier, the pilot subcarrier, and the data subcarrier comprise a subset of values comprising 1, −

1, 1, 1, −

1, 1, 1, −

1, 1, 1, 1, −

1, 1, 0, −

1, −

1, −

1, 1, −

1, −

1, −

1, 1, 1, 1, −

1, −

1, and −

1.

78. The method of claim 76, wherein the values corresponding to the direct current subcarrier, the pilot subcarrier, and the data subcarrier corresponds to indices in a range from −

12 to +12, and wherein the values corresponding to the direct current subcarrier, the pilot subcarrier, and the data subcarrier comprise a subset of values comprising 1, 1, −

1, 1, −

1, 1, 1, 1, 1, −

1, −

1, 1, 0, 1, 1, 1, 1, 1, −

1, −

1, 1, −

1, −

1, −

1, and 1.

79. The method of claim 76, wherein the values comprise 0, 0, 0, 1, −

1, −

1, 1, −

1, 1, 1, −

1, 1, −

1, −

1, −

1, −

1, 0, −

1, −

1, −

1, 1, −

1, −

1, −

1, 1, −

1, 1, 1, 1, −

1, 0, and 0.

80. The method of claim 76, wherein the values comprise 0, 0, 0, 1, 1, −

1, −

1, 1, 1, 1, −

1, −

1, 1, 1, −

1, 1, 0, −

1, 1, 1, −

1, 1, −

1, −

1, −

1, 1, 1, 1, 1, 1, 0, and 0.

81. The method of claim 65, wherein a orthogonality metric of one of the one or more LTF sequences and either half of an additional LTF sequence comprising sixty four values is substantially equivalent to zero, wherein the one or more LTF sequences correspond to a first channel and the additional LTF sequence corresponds to a second channel.

82. The method of claim 65, wherein the one or more LTF sequences comprise two LTF sequences forming a part of a preamble of the data unit for use with communicating on a first channel, wherein the two TLF sequences span two symbols of the preamble.

83. The method of claim 82, wherein the two symbols are power boosted by 2 dB to 4 dB.

84. The method of claim 83, wherein the two symbols are power boosted for transmissions only where data for the data unit is encoded based on a 2×

repetition of BPSK rate one-half.

85. The method of claim 82 wherein the first channel corresponds to a 1 MHz channel.

86. A wireless communication apparatus, comprising:

a receiver configured to receive one or more long training field (LTF) sequences comprising thirty two values or less, wherein each of the values of the one or more LTF sequences correspond to one of a guard subcarrier, a direct current subcarrier, a pilot subcarrier, and a data subcarrier, wherein each of the values corresponding to the pilot subcarrier and the data subcarrier comprise a value of either one or negative one, and wherein each of the values corresponding to the guard subcarrier and the direct current subcarrier comprises a value of zero; and

a processor configured to decode one or more data symbols based at least in part on the one or more LTF sequences.

87. A wireless communication apparatus, comprising:

means for receiving one or more long training field (LTF) sequences comprising thirty two values or less, wherein each of the values of the one or more LTF sequences correspond to one of a guard subcarrier, a direct current subcarrier, a pilot subcarrier, and a data subcarrier, wherein each of the values corresponding to the pilot subcarrier and the data subcarrier comprise a value of either one or negative one, and wherein each of the values corresponding to the guard subcarrier and the direct current subcarrier comprises a value of zero; and

means for decoding one or more data symbols based at least in part on the one or more LTF sequences.

88. A method for wireless communication, comprising:

generating a training field sequence comprising thirty two values, wherein each value corresponds to a wireless subcarrier, the training field sequence comprising values corresponding to;

seven guard subcarriers;

one DC subcarrier;

twenty two data subcarriers; and

two pilot subcarriers; and

transmitting the training field sequence over a wireless subcarrier.

89. The method of claim 88, wherein the thirty values corresponds to indices in a range from −

16 to +15, and wherein a first pilot of the two pilot values has an index of −

7 and a second pilot of the two pilot values has an index of +7.

90. The method of claim 88, wherein the thirty values corresponds to indices in a range from −

16 to +15, and wherein a first pilot of the two pilot values has an index of −

9 and a second pilot of the two pilot values has an index of 5.

91. A method for wireless communication, comprising:

generating one or more short training field (STF) sequences comprising thirty two values or less, wherein the STF sequence comprises values of 0, 0, 0, 0, 1+j, 0, 0, 0, −

1−

j, 0, 0, 0, 1+j, 0, 0, 0, 0, 0, 0, 0, −

1−

j, 0, 0, 0, −

1−

j, 0, 0, 0, −

1−

j, 0, 0, and 0; and

transmitting a data unit comprising the one or more STF sequences over a wireless channel.

92. A method for wireless communication, comprising:

generating one or more short training field (STF) sequences comprising thirty two values or less, wherein a peak-to-average power ratio of a time domain signal generated from the one or more STF sequences has value that is less than 3 dB; and

transmitting a data unit comprising the one or more STF sequences over a wireless channel.

93. A method for wireless communication, comprising:

receiving one or more short training field (STF) sequences comprising thirty two values or less, wherein the STF sequence comprises values of 0, 0, 0, 0, 1+j, 0, 0, 0, −

1−

j, 0, 0, 0, 1+j, 0, 0, 0, 0, 0, 0, 0, −

1−

j, 0, 0, 0, −

1−

j, 0, 0, 0, −

1−

j, 0, 0, and 0; and

decoding one or more data symbols based at least in part on the one or more STF sequences.

94. A method for wireless communication, comprising:

receiving one or more short training field (STF) sequences comprising thirty two values or less, wherein a peak-to-average power ratio of a time domain signal generated from the one or more STF sequences has value that is less than 3 dB; and

decoding one or more data symbols based at least in part on the one or more STF sequences.

95. A method for wireless communication, comprising:

generating one or more short training field (STF) sequences comprising thirty two values or less, wherein the one or more STF sequences comprises a subset of values comprising non-zero values, and wherein at least one of the non-zero values has a different assigned value than at least one other of the non-zero values; and

transmitting a data unit comprising the one or more STF sequences over a wireless channel.

96. The method of claim 95, wherein a first subset of non-zero tones of the one or more STF sequences at the beginning of the one or more STF sequences and a second subset of non-zero tones at the end of the one or more STF sequences comprise values that are less than the values assigned to a third subset of non-zero tones between the first subset and the second subset.

97. The method of claim 95, wherein there is a 3 db reduction in power on the beginning and ending non-zero tones of the one or more STF sequences.

98. The method of claim 95, wherein the one or more STF sequences comprises values of 0, 0, 0, 0, √

{square root over (1/2)}(1+j), 0, 0, 0, −

1−

j, 0, 0, 0, 1+j, 0, 0, 0, 0, 0, 0, 0, −

1−

j, 0, 0, 0, −

1−

j, 0, 0, 0, −

√

{square root over (1/2)}(1+j), 0, 0, and 0.

99. A method for wireless communication, comprising:

receiving one or more short training field (STF) sequences comprising thirty two values or less, wherein the one or more STF sequences comprises a subset of values comprising non-zero values, and wherein at least one of the non-zero values has a different assigned value than at least one other of the non-zero values; and

decoding one or more data symbols based at least in part on the one or more STF sequences.

100. The method of claim 99, wherein a first subset of non-zero tones of the one or more STF sequences at the beginning of the one or more STF sequences and a second subset of non-zero tones at the end of the one or more STF sequences comprise values that are less than the values assigned to a third subset of non-zero tones between the first subset and the second subset.

101. The method of claim 99, wherein there is a 3 db reduction in power on the beginning and ending non-zero tones of the one or more STF sequences.

102. The method of claim 99, wherein the one or more STF sequences comprises values of 0, 0, 0, 0, √

{square root over (1/2)}(1+j), 0, 0, 0, −

1−

j, 0, 0, 0, 1+j, 0, 0, 0, 0, 0, 0, 0, −

1−

j, 0, 0, 0, −

1−

j, 0, 0, 0, −

√

{square root over (1/2)}(1+j), 0, 0, and 0.

103. A physical layer device configured to generate one or more short training field (STF) sequences comprising thirty two values or less, wherein:

the one or more STF sequences comprises a first subset of values comprising values of zero and non-zero values,

the non-zero values are located at indices of the first subset that are at least a multiple of two, wherein the one or more STF sequences comprises a second subset of zero values, and

the second subset of zero values comprises all values not included within the first subset.

104. A station, comprising:

a physical layer device configured to generate one or more short training field (STF) sequences comprising thirty two values or less, wherein;

the one or more STF sequences comprises a first subset of values comprising values of zero and non-zero values,

the non-zero values are located at indices of the first subset that are at least a multiple of two, wherein the one or more STF sequences comprises a second subset of zero values, and

the second subset of zero values comprises all values not included within the first subset.

105. An access point, comprising:

a physical layer device configured to generate one or more short training field (STF) sequences comprising thirty two values or less, wherein;

the one or more STF sequences comprises a first subset of values comprising values of zero and non-zero values,

the non-zero values are located at indices of the first subset that are at least a multiple of two, wherein the one or more STF sequences comprises a second subset of zero values, and

the second subset of zero values comprises all values not included within the first subset.

106. A physical layer device configured to generate one or more long training field (LTF) sequences comprising thirty two values or less, wherein:

each of the values of the one or more LTF sequences correspond to one of a guard subcarrier, a direct current subcarrier, a pilot subcarrier, and a data subcarrier,

each of the values corresponding to the pilot subcarrier and the data subcarrier comprise a value of either one or negative one, and

each of the values corresponding to the guard subcarrier and the direct current subcarrier comprises a value of zero.

107. A station, comprising a physical layer device configured to generate one or more long training field (LTF) sequences comprising thirty two values or less, wherein:

each of the values of the one or more LTF sequences correspond to one of a guard subcarrier, a direct current subcarrier, a pilot subcarrier, and a data subcarrier,

each of the values corresponding to the pilot subcarrier and the data subcarrier comprise a value of either one or negative one, and

each of the values corresponding to the guard subcarrier and the direct current subcarrier comprises a value of zero.

108. An access point, comprising a physical layer device configured to generate one or more long training field (LTF) sequences comprising thirty two values or less, wherein:

each of the values of the one or more LTF sequences correspond to one of a guard subcarrier, a direct current subcarrier, a pilot subcarrier, and a data subcarrier,

each of the values corresponding to the pilot subcarrier and the data subcarrier comprise a value of either one or negative one, and

each of the values corresponding to the guard subcarrier and the direct current subcarrier comprises a value of zero.

109. A physical layer device, comprising a circuit configured:

to receive a data unit comprising one or more short training field (STF) sequences comprising thirty two values or less, wherein;

the one or more STF sequences comprises a first subset of values comprising values of zero and non-zero values, wherein the non-zero values are located at indices of the first subset that are at least a multiple of two,

the one or more STF sequences comprises a second subset of zero values, and

the second subset of zero values comprises all values not included within the first subset; and

to decode one or more data symbols based at least in part on the one or more STF sequences.

110. A station, comprising a physical layer device configured:

to receive a data unit comprising one or more short training field (STF) sequences comprising thirty two values or less, wherein;

the one or more STF sequences comprises a first subset of values comprising values of zero and non-zero values, wherein the non-zero values are located at indices of the first subset that are at least a multiple of two,

the one or more STF sequences comprises a second subset of zero values, and

the second subset of zero values comprises all values not included within the first subset; and

to decode one or more data symbols based at least in part on the one or more STF sequences.

111. An access point, comprising a physical layer device configured:

to receive a data unit comprising one or more short training field (STF) sequences comprising thirty two values or less, wherein;

the one or more STF sequences comprises a first subset of values comprising values of zero and non-zero values, wherein the non-zero values are located at indices of the first subset that are at least a multiple of two,

the one or more STF sequences comprises a second subset of zero values, and

the second subset of zero values comprises all values not included within the first subset; and

to decode one or more data symbols based at least in part on the one or more STF sequences.

112. A physical layer device, comprising a circuit configured:

to receive one or more long training field (LTF) sequences comprising thirty two values or less, wherein;

each of the values of the one or more LTF sequences correspond to one of a guard subcarrier, a direct current subcarrier, a pilot subcarrier, and a data subcarrier,

each of the values corresponding to the pilot subcarrier and the data subcarrier comprise a value of either one or negative one, and

each of the values corresponding to the guard subcarrier and the direct current subcarrier comprises a value of zero; and

to decode one or more data symbols based at least in part on the one or more LTF sequences.

113. A station, comprising a physical layer device configured:

to receive one or more long training field (LTF) sequences comprising thirty two values or less, wherein;

each of the values of the one or more LTF sequences correspond to one of a guard subcarrier, a direct current subcarrier, a pilot subcarrier, and a data subcarrier,

each of the values corresponding to the pilot subcarrier and the data subcarrier comprise a value of either one or negative one, and

each of the values corresponding to the guard subcarrier and the direct current subcarrier comprises a value of zero; and

to decode one or more data symbols based at least in part on the one or more LTF sequences.

114. An access point, comprising a physical layer device configured:

to receive one or more long training field (LTF) sequences comprising thirty two values or less, wherein;

each of the values of the one or more LTF sequences correspond to one of a guard subcarrier, a direct current subcarrier, a pilot subcarrier, and a data subcarrier,

each of the values corresponding to the pilot subcarrier and the data subcarrier comprise a value of either one or negative one, and

each of the values corresponding to the guard subcarrier and the direct current subcarrier comprises a value of zero; and

to decode one or more data symbols based at least in part on the one or more LTF sequences.