Long training field sequence construction

Patent metadata

Field	Value
Publication number	US-2016286551-A1
Application number	US-201615079007-A
Country	US
Kind code	A1
Filing date	Mar 23, 2016
Priority date	Mar 25, 2015
Publication date	Sep 29, 2016
Grant date	—

Abstract

In wireless communications, a first device may determine a channel bandwidth and a high efficiency long training field (HE-LTF) mode. The first device may generate an HE-LTF symbol by using an HE-LTF sequence corresponding to the determined channel bandwidth and HE-LTF mode. The first device may transmit, in the determined channel bandwidth, a high efficiency physical layer convergence procedure (PLCP) protocol data unit (HE PPDU) that includes the HE-LTF symbol. A second device may receive, in a channel bandwidth, a downlink HE PPDU that includes an HE-LTF symbol. The second device may obtain, from the HE-LTF symbol, an HE-LTF sequence corresponding to the channel bandwidth and an HE-LTF mode of the HE-LTF symbol. The downlink HE PPDU may be the HE PPDU from the first device. Other methods, apparatus, and computer-readable media are also disclosed.

First claim

What is claimed is:

1 . An apparatus for facilitating wireless communication, the apparatus comprising:
one or more memories; and one or more processors coupled to the one or more memories, the one or more processors configured to cause:
determining a channel bandwidth among a plurality of bandwidths including a 20 megahertz (MHz) channel bandwidth, 40 MHz channel bandwidth, and 80 MHz channel bandwidth;
determining a high efficiency long training field (HE-LTF) mode among a plurality of HE-LTF modes including a 4×HE-LTF mode and a 2×HE-LTF mode;
generating an HE-LTF symbol by using an HE-LTF sequence corresponding to the determined channel bandwidth and the determined HE-LTF mode, wherein the HE-LTF sequence is among a plurality of HE-LTF sequences for the plurality of bandwidths and the plurality of HE-LTF modes; and
transmitting a high efficiency physical layer convergence procedure (PLCP) protocol data unit (HE PPDU) including the HE-LTF symbol, in the determined channel bandwidth.

2 . The apparatus of claim 1 , wherein the plurality of HE-LTF sequences includes a first HE-LTF sequence for the 20 MHz channel bandwidth and the 4×HE-LTF mode, a second HE-LTF sequence for the 20 MHz channel bandwidth and the 2×HE-LTF mode, a third HE-LTF sequence for the 40 MHz channel bandwidth and the 4×HE-LTF mode, a fourth HE-LTF sequence for the 40 MHz channel bandwidth and the 2×HE-LTF mode, a fifth HE-LTF sequence for the 80 MHz channel bandwidth and the 4×HE-LTF mode, and a sixth HE-LTF sequence for the 80 MHz channel bandwidth and the 2×HE-LTF mode.

3 . The apparatus of claim 2 , wherein the fourth HE-LTF sequence includes zero values on every odd subcarrier index from −244 to −4, non-zero values on every even subcarrier index from −244 to −4, a zero value on a subcarrier index of −3, direct current (DC) tones on subcarrier indices from −2 to 2, a zero value on a subcarrier index of 3, non-zero values on every even subcarrier index from 4 to 244, and zero values on every odd subcarrier index from 4 to 244.

4 . The apparatus of claim 3 , wherein the fourth HE-LTF sequence includes plural unit sequences for plural resource units, wherein each of the plural unit sequences corresponds to one of plural base sequences multiplied by +1 or −1.

5 . The apparatus of claim 4 , wherein the number of the plural unit sequences is 18, the number of the plural resource units is 18, and each of the plural unit sequences has 26 elements whose value are +1 or −1.

6 . The apparatus of claim 2 , wherein the third HE-LTF sequence includes non-zero values on subcarrier indices from −244 to −3, direct current (DC) tones on subcarrier indices from −2 to 2, and non-zero values on subcarrier indices from 3 to 244.

7 . The apparatus of claim 6 , wherein the third HE-LTF sequence includes plural unit sequences for plural resource units, wherein each of the plural unit sequences corresponds to one of plural base sequences multiplied by +1 or −1.

8 . The apparatus of claim 7 , wherein the number of the plural unit sequences is 18, the number of the plural resource units is 18, and each of the plural unit sequences has 26 elements whose value are +1 or −1.

9 . The apparatus of claim 7 , wherein the number of the plural base sequences is 2.

10 . The apparatus of claim 2 , wherein the first HE-LTF sequence includes non-zero values on subcarrier indices from −122 to −2, direct current (DC) tones on subcarrier indices from −1 to 1, and non-zero values on subcarrier indices from 2 to 122, and
wherein the second HE-LTF sequence includes zero values on every odd subcarrier index from −122 to −2, non-zero values on every even subcarrier index from −122 to −2, DC tones on subcarrier indices from −1 to 1, non-zero values on every even subcarrier index from 2 to 122, and zero values on every odd subcarrier index from 2 to 122.

11 . The apparatus of claim 2 , wherein the fifth HE-LTF sequence includes non-zero values on subcarrier indices from −500 to −3, direct current (DC) tones on subcarrier indices from −2 to 2, and non-zero values on subcarrier indices from 3 to 500, and
wherein the sixth HE-LTF sequence includes zero values on every odd subcarrier index from −500 to −4, non-zero values on every even subcarrier index from −500 to −4, a zero value on a subcarrier index of −3, DC tones on subcarrier indices from −2 to 2, a zero value on a subcarrier index of 3, non-zero values on every even subcarrier index from 4 to 500, and zero values on every odd subcarrier index from 4 to 500.

12 . The apparatus of claim 2 , wherein the plurality of HE-LTF modes further includes a 1×HE-LTF mode,
wherein the plurality of HE-LTF sequences further includes a seventh HE-LTF sequence for the 20 MHz channel bandwidth and the 1×HE-LTF mode, an eighth HE-LTF sequence for the 40 MHz channel bandwidth and the 1×HE-LTF mode, and a ninth HE-LTF sequence for the 80 MHz channel bandwidth and the 1×HE-LTF mode,
wherein the seventh HE-LTF sequence includes zero values on subcarrier indices from −122 to −4 excluding every fourth subcarrier index from −122 to −4, non-zero values on every fourth subcarrier index from −122 to −4, zero values on subcarrier indices of −3 and −2, direct current (DC) tones on subcarrier indices from −1 to 1, zero values on subcarrier indices of 2 and 3, non-zero values on every fourth subcarrier index from 4 to 122, and zero values on subcarrier indices from 4 to 122 excluding every fourth subcarrier index from 4 to 122,
wherein the eighth HE-LTF sequence includes zero values on subcarrier indices from −244 to −4 excluding every fourth subcarrier index from −244 to −4, non-zero values on every fourth subcarrier index from −244 to −4, a zero value on a subcarrier index of −3, DC tones on subcarrier indices from −2 to 2, a zero value on a subcarrier index of 3, non-zero values on every fourth subcarrier index from 4 to 244, and zero values on subcarrier indices from 4 to 244 excluding every fourth subcarrier index from 4 to 122, and
wherein the ninth HE-LTF sequence includes zero values on subcarrier indices from −500 to −4 excluding every fourth subcarrier index from −500 to −4, non-zero values on every fourth subcarrier index from −500 to −4, a zero value on a subcarrier index of −3, DC tones on subcarrier indices from −2 to 2, a zero value on a subcarrier index of 3, non-zero values on every fourth subcarrier index from 4 to 500, and zero values on subcarrier indices from 4 to 500 excluding every fourth subcarrier index from 4 to 500.

13 . The apparatus of claim 1 , wherein a duration of the HE-LTF symbol excluding a guard interval is 12.8 microseconds when the determined HE-LTF mode is 4×HE-LTF mode, and
wherein a duration of the HE-LTF symbol excluding a guard interval is 6.4 microseconds when the determined HE-LTF mode is 2×HE-LTF mode.

14 . The apparatus of claim 1 , wherein the HE PPDU is a downlink non-orthogonal frequency division multiple access (non-OFDMA) PPDU.

15 . The apparatus of claim 1 , wherein a part of the HE-LTF sequence is used for generating the HE-LTF symbol, the part corresponds to a resource unit which is allocated to the apparatus, and the HE PPDU is an uplink non-orthogonal frequency division multiple access (non-OFDMA) PPDU.

16 . An apparatus for facilitating wireless communication, the apparatus comprising:
one or more memories; and one or more processors coupled to the one or more memories, the one or more processors configured to cause:
receiving a downlink high efficiency physical layer convergence procedure (PLCP) protocol data unit (HE PPDU) including a high efficiency long t

Assignees

• Newracom Inc

Inventors

• Lee Daewon
• Moon Sungho
• Noh Yujin
• Cheong Minho

Classifications

• H04L25/0204

  of multiple channels · CPC title

• H04L27/26

  Systems using multi-frequency codes (H04L27/32 takes precedence) · CPC title

• H04B7/0452

  Multi-user MIMO systems · CPC title

• H04L25/00

  Baseband systems · CPC title

• H04L25/0226

  sounding signals per se · CPC title