Pilot transmission and reception for orthogonal frequency division multiple access

Patent metadata

Field	Value
Publication number	US-2016330000-A1
Application number	US-201615150127-A
Country	US
Kind code	A1
Filing date	May 9, 2016
Priority date	May 8, 2015
Publication date	Nov 10, 2016
Grant date	—

Abstract

A wireless device transmits a frame by determining a plurality of Resource Units (RUs) of the frame, providing pilots in a first RU of the frame at a first set of positions, providing pilots in a second RU of the frame at a second set of positions, and transmitting the frame. The first set of positions is different from the second set of positions. A wireless device receives a frame including an RU including pilots and processes the pilots. When an RU for the data symbol includes an odd-numbered lowest subcarrier, the pilots are included at a first set of positions in the resource unit. When the RU includes an even-numbered lowest subcarrier, the pilots are included at a second set of positions in the resource unit. The second set of positions is different from the first set of positions.

First claim

What is claimed is:

1 . A method of a wireless device for transmitting a frame, the method comprising:
determining, by the wireless device, a plurality of Resource Units (RUs) of the frame; providing a first plurality of pilots in a first RU of the frame at a first set of positions, respectively; providing a second plurality of pilots in a second RU of the frame at a second set of positions, respectively; and transmitting the frame, wherein the first set of positions is different from the second set of positions.

2 . The method of claim 1 , wherein the frame is an Orthogonal Frequency Division Multiple Access (OFDMA) frame and the plurality of RUs include respective pluralities of subcarriers.

3 . The method of claim 2 , wherein the first RU includes a lowest subcarrier having an odd-numbered index, and
wherein the second RU includes a lowest subcarrier having an even-numbered index.

4 . The method of claim 3 , wherein the first RU is a 52-subcarrier RU and the second RUs is a 52-subcarrier RU.

5 . The method of claim 4 , wherein the first set of positions include a first pilot tone position spaced five subcarriers away from a lowest-indexed subcarrier of the first RU, a second pilot tone position separated by thirteen subcarriers from the first pilot tone position, a third pilot tone position separated by eleven subcarriers from the second pilot tone position, and a fourth pilot tone position separated by thirteen subcarriers from the third pilot tone position and spaced six subcarriers away from a highest-indexed subcarrier of the first RU, and
wherein the second set of positions include a fifth pilot tone position spaced six subcarriers away from a lowest-indexed subcarrier of the first RU, a sixth pilot tone position separated by thirteen subcarriers from the fifth pilot tone position, a seventh pilot tone position separated by eleven subcarriers from the sixth pilot tone position, and an eighth pilot tone position separated by thirteen subcarriers from the seventh pilot tone position and spaced five subcarriers away from a highest-indexed subcarrier of the second RU.

6 . The method of claim 3 , wherein the first RU is a 26-subcarrier RU, and
wherein the second RU is a 26-subcarrier RU.

7 . The method of claim 6 , wherein the first set of positions include a first pilot tone position spaced five subcarriers away from a lowest-indexed subcarrier of the first RU and a second pilot tone position separated by thirteen subcarriers from the first pilot tone position and spaced six subcarriers away from a highest-indexed subcarrier of the first RU, and
wherein the second set of positions includes a third pilot tone position spaced six subcarriers away from a lowest-indexed subcarrier of the second RU and a fourth pilot tone position separated by thirteen subcarriers from the third pilot tone position and spaced five subcarriers away from a highest-indexed subcarrier of the second RU.

8 . The method of claim 6 , the method further comprising:
providing a third plurality of pilots in a third RU of the frame at a third set of positions, respectively, wherein the second set of positions is different from the third set of positions, wherein the third RU is a 26-subcarrier RU, and wherein the third RU is a center RU that is split into 13 positive-indexed subcarriers and 13 negative-indexed subcarriers by DC tones.

9 . The method of claim 8 , wherein the third set of positions includes a fifth pilot tone position spaced six subcarriers away from a lowest-indexed subcarrier of the third RU and a sixth pilot tone position spaced six subcarriers away from a highest-indexed subcarrier of the third RU

10 . The method of claim 1 , wherein the first set of positions is a mirror image of the second set of positions.

11 . The method of claim 1 , wherein the frame includes a 2X High Efficiency (HE) Long Training Field (HE-LTF), and
wherein the first set of positions respectively correspond to locations of non-null subcarriers of symbols of the 2X HE-LTF, and wherein the second set of positions respectively correspond to the locations of the non-null subcarriers of the symbols of the 2X HE-LTF.

12 . The method of claim 1 , wherein pilot tone positions for all RUs in a lower half of a 20 MHz channel are mirror symmetric to pilot one positions for corresponding mirrored RUs in an upper half of the 20 MHz channel.

13 . The method of claim 1 , wherein pilot tone positions for all RUs in a lower half of a 40 MHz channel are mirror symmetric to pilot tone positions for corresponding mirrored RUs in an upper half of the 40 MHz channel.

14 . A method of a wireless device for transmitting a frame, the method comprising:
providing pilots in a resource unit; and transmitting the frame including the resource unit, wherein when a lowest subcarrier of the resource unit has an odd index, a plurality of pilots are included at a first set of positions in the resource unit, respectively, wherein when a lowest subcarrier of the resource unit has an even index, a plurality of pilots are included at a second set of positions in the resource unit, respectively, wherein the second set of positions is different from the first set of positions.

15 . The method of claim 14 , wherein the resource unit is a 52-subcarrier resource unit.

16 . The method of claim 15 , wherein the first set of positions include a first pilot tone position spaced five subcarriers away from a lowest-indexed subcarrier of the resource unit, a second pilot tone position separated by thirteen subcarriers from the first pilot tone position, a third pilot tone position separated by eleven subcarriers from the second pilot tone position, and a fourth pilot tone position separated by thirteen subcarriers from the third pilot tone position and spaced six subcarriers away from a highest-indexed subcarrier of the resource unit, and
wherein the second set of positions include a fifth pilot tone position spaced six subcarriers away from a lowest-indexed subcarrier of the resource unit, a sixth pilot tone position tone separated by thirteen subcarriers from the fifth pilot tone position, a seventh pilot tone position separated by eleven subcarriers from the sixth pilot tone position, and an eighth pilot tone position separated by thirteen subcarriers from the seventh pilot tone position and spaced five subcarriers away from a highest-indexed subcarrier of the resource unit.

17 . The method of claim 14 , wherein the resource unit is a 26-subcarrier resource unit.

18 . The method of claim 17 , wherein the first set of positions include a first pilot tone position spaced five subcarriers away from a lowest-indexed subcarrier of the resource unit and a second pilot tone position separated by thirteen subcarriers from the first pilot tone position and spaced six subcarriers away from a highest-indexed subcarrier of the resource unit, and
wherein the second set of positions include includes a third pilot tone position spaced six subcarriers away from a lowest-indexed subcarrier of the resource unit and a fourth pilot tone position separated by thirteen subcarriers from the third pilot tone position and spaced five subcarriers away from a highest-indexed subcarrier of the resource unit.

19 . The method of claim 17 ,
wherein when the resource unit is a center resource unit that is split into 13 negative-indexed subcarriers and 13 positive-indexed subcarriers by DC tones, a plurality of pilots are included at a third set of positions in the resource unit, respective

Assignees

• Newracom Inc

Inventors

• Lee Dae Won
• Kwon Young Hoon
• Moon Sungho
• Noh Yujin

Classifications

• H04W72/20

  Control channels or signalling for resource management · CPC title

• H04W84/12

  WLAN [Wireless Local Area Networks] · CPC title

• H04L27/2657

  Carrier synchronisation · CPC title

• H04L5/0048 Primary

  Allocation of pilot signals, i.e. of signals known to the receiver (allocation of control signalling H04L5/0053; use of control signalling H04L5/0091) · CPC title

• H04L27/0014

  Carrier regulation (of chaotic carriers H04L27/001; for multicarrier receivers H04L27/2657) · CPC title