Data transmission method and apparatus in wireless local area network

Patent metadata

Field	Value
Publication number	US-10999119-B2
Application number	US-202016870570-A
Country	US
Kind code	B2
Filing date	May 8, 2020
Priority date	Nov 23, 2015
Publication date	May 4, 2021
Grant date	May 4, 2021

Abstract

An HE-LTF transmission method is provided, including: determining, based on a total number N STS of space-time streams, a number N HELTF of OFDM symbols included in an HE-LTF field; determining a HE-LTF sequence in frequency domain according to a transmission bandwidth and a mode of the HE-LTF field, where the HE-LTF sequence in frequency domain includes but is not limited to a mode of the HE-LTF field sequence that is in a 1× mode and that is mentioned in implementations; and sending a time-domain signal according to the number N HELTF of OFDM symbols and the determined HE-LTF sequence in frequency domain. In the foregoing solution, a PAPR value is relatively low.

First claim

What is claimed is:

1. A method for channel estimation information transmission, the method comprising:
determining, by an apparatus, a long training field (LTF) sequence in a frequency domain according to a transmission bandwidth and a mode of a LTF field; and
sending, by the apparatus, a time-domain signal according to the LTF sequence and a number of orthogonal frequency division multiplexing (OFDM) symbols of the LTF field;
wherein the LTF sequence in the frequency domain in a 1× LTF mode over a bandwidth that includes multiple 80 MHz channels corresponds to a LTF sequence that comprises any or combination of the following: a left part of a long training field sequence for a 80 MHz channel A_(L-LTF 80MHz_A ) a right part of the long training field sequence for the 80 MHz channel A (R-LTF 80MHz_A ), -L-LTF 80MHz_A , or -R-LTF 80MHz_A ;
wherein {L-LTF 80MHz_A , 0, R-LTF 80MHz_A }={−1, −1, +1, +1, +1, +1, +1, −1, −1, −1, +1, +1, −1, −1, +1, −1, +1, −1, −1, −1, −1, −1, −1, +1, +1, −1, −1, +1, −1, + 1 , − 1 , − 1 , − 1 , − 1 , − 1 , + 1 , + 1 , − 1 , − 1 , + 1 , − 1 , + 1 , − 1 , + 1 , + 1 , + 1 , + 1 , + 1 , − 1 , − 1 , + 1 , + 1 , − 1 , + 1 , − 1 , + 1 , − 1 , − 1 , − 1 , − 1 , + 1 , − 1 , − 1 , − 1 , − 1 , − 1 , − 1 , + 1 , + 1 , + 1 , − 1 , − 1 , + 1 , + 1 , − 1 , + 1 , − 1 , + 1 , + 1 , + 1 , + 1 , + 1 , + 1 , − 1 , − 1 , + 1 , + 1 , − 1 , + 1 , − 1 , + 1 , + 1 , + 1 , + 1 , − 1 , + 1 , + 1 , − 1 , − 1 , + 1 , − 1 , + 1 , − 1 , + 1 , + 1 , + 1 , + 1 , + 1 , − 1 , − 1 , + 1 , + 1 , − 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 , − 1 , + 1 , + 1 , + 1 , + 1 , + 1 , + 1 , − 1 , − 1 , + 1 , + 1 , − 1 , + 1 , − 1 , + 1 , + 1 , + 1 , + 1 , + 1 , − 1 , − 1 , + 1 , + 1 , − 1 , + 1 , − 1 , + 1 , − 1 , − 1 , − 1 , − 1 , − 1 , + 1 , + 1 , − 1 , − 1 , + 1 , − 1 , + 1 , − 1 , + 1 , + 1 , + 1 , + 1 , − 1 , + 1 , − 1 , − 1 , + 1 , − 1 , − 1 , + 1 , + 1 , + 1 , − 1 , − 1 , + 1 , + 1 , − 1 , + 1 , − 1 , + 1 , + 1 , + 1 , + 1 , + 1 , + 1 , − 1 , − 1 , + 1 , + 1 , − 1 , + 1 , − 1 , + 1 , + 1 , + 1 , + 1 , − 1 , + 1 , + 1 , − 1 , − 1 , + 1 , − 1 , + 1 , − 1 , + 1 , + 1 , + 1 , + 1 , + 1 , − 1 , − 1 , + 1 , + 1 , − 1 , + 1 , − 1 , + 1 , − 1 , − 1 , − 1 , − 1 , + 1 , − 1 , + 1 , − 1 , − 1 , − 1 , + 1 , + 1 }.

2. The method according to claim 1 ,
wherein the bandwidth includes a first 80 MHz channel and a second 80 MHz channel following the first 80 MHz channel in the frequency domain;
wherein the LTF field includes a sequence BI, and the sequence BI is a sequence carried on a subcarrier between subcarriers on edges of the first 80 MHz channel and the second 80 MHz channel; and
wherein the sequence BI is full 0.

3. The method according to claim 1 , further comprising:
before determining the LTF sequence in the frequency domain, receiving a trigger frame to indicate uplink scheduling information in an uplink multi-user multiple-input multiple-output (UL-MU-MIMO) transmission, wherein the uplink scheduling information includes the transmission bandwidth and the number of OFDM symbols of the LTF field.

4. The method according to claim 1 , further comprising:
determining the number of OFDM symbols of the LTF field based on a total number of space-time streams(N STS ) in a single user transmission or in a downlink multi-user multiple-input multiple-output (DL-MU-MIMO) transmission, wherein the number of OFDM symbols of the LTF field and the N STS correspond as follows:

number of OFDM symbols

N STS
of the LTF field

1
1

2
2

3
4

4
4

5
6

6
6

7
8

8
8

5. A method for channel estimation information processing, the method comprising:
receiving, by an apparatus, a preamble that comprises a long training field (LTF); and
obtaining, by the apparatus, a channel estimation value of a corresponding subcarrier location according to the LTF field and a LTF sequence in a frequency domain,
wherein the LTF sequence in the frequency domain in a 1× LTF mode over a bandwidth that includes multiple 80 MHz channels corresponds to a LTF sequence that comprises any or combination of the following: a left part of a long training field sequence for a 80 MHz channel A_(L-LTF 80MHz_A ) a right part of the long training field sequence for the 80 MHz channel A (R-LTF 80MHz_A ), -L-LTF 80MHz_A , or -R-LTF 80MHz_A ;
wherein {L-LTF 80MHz_A , 0, R-LTF 80MHz_A }={−1, −1, +1, +1, +1, +1, +1, −1, −1, −1, +1, +1, −1, −1, +1, −1, +1, −1, −1, −1, −1, −1, −1, +1, +1, −1, −1, +1, −1, +1, −1, −1, −1, −1, −1, +1, +1, −1, −1, +1, −1, +1, −1, +1, +1, +1, +1, +1, −1, −1, +1, +1, −1, +1, −1, +1, −1, −1, −1, −1, +1, −1, −1, −1, −1, −1, −1, +1, +1, +1, −1, −1, +1, +1, −1, +1, −1, +1, +1, +1, +1, +1, +1, −1, −1, +1, +1, −1, +1, −1, +1, +1, +1, +1, −1, +1, +1, −1, −1, +1, −1, +1, −1, +1, +1, +1, +1, +1, −1, −1, +1, +1, −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, −1, +1, +1, +1, +1, +1, +1, −1, −1, +1, +1, −1, +1, −1, +1, +1, +1, +1, +1, −1, −1, +1, +1, −1, +1, −1, +1, −1, −1, −1, −1, −1, +1, +1, −1, −1, +1, −1, +1, −1, +1, +1, +1, +1, −1, +1, −1, −1, +1, −1, −1, +1, +1, +1, −1, −1, +1, +1, −1, +1, −1, +1, +1, +1, +1, +1, +1, −1, −1, +1, +1, −1, +1, −1, +1, +1, +1, +1, −1, +1, +1, −1, −1, +1, −1, +1, −1, +1, +1, +1, +1, +1, −1, −1, +1, +1, −1, +1, −1, +1, −1, −1, −1, −1, +1, −1, +1, −, −1, −1, +1, +1}.

6. The method according to claim 5 ,
wherein the bandwidth includes a first 80 MHz channel and a second 80 MHz channel following the first 80 MHz channel in the frequency domain;
wherein the LTF field includes a sequence BI, and the sequence BI is a sequence carried on a subcarrier between subcarriers on edges of the first 80 MHz channel and the second 80 MHz channel; and
wherein the sequence BI is full 0.

7. The method according to claim 5 , further comprising:
before receiving the preamble that comprises the LTF field, sending, by the apparatus, a trigger frame to indicate uplink scheduling information in an uplink multi-user multiple-input multiple-output (UL-MU-MIMO) transmission, wherein the uplink scheduling information includes a transmission bandwidth and a number of orthogonal frequency division multiplexing (OFDM) symbols of the LTF field.

8. The method according to claim 5 , further comprising:
obtaining, by the apparatus, a transmission bandwidth BW, a to

Assignees

• Huawei Tech Co Ltd

Inventors

• Lin Wei
• Xue Xin
• Wang Ningjuan
• Liu Le

Classifications

• H04W72/23

  in the downlink direction of a wireless link, i.e. towards a terminal · CPC title

• H04L25/02 Primary

  Details {; arrangements for supplying electrical power along data transmission lines (systems for transmitting signals via power distribution lines H04B3/54)} · CPC title

• H04W84/12

  WLAN [Wireless Local Area Networks] · CPC title

• H04L27/2695

  with channel estimation, e.g. determination of delay spread, derivative or peak tracking (channel estimation H04L25/0202) · CPC title

• H04L27/26

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