Method for multi-user transmission and reception in wireless communication system and device for same

Patent metadata

Field	Value
Publication number	US-10439780-B2
Application number	US-201515548706-A
Country	US
Kind code	B2
Filing date	Nov 30, 2015
Priority date	Feb 4, 2015
Publication date	Oct 8, 2019
Grant date	Oct 8, 2019

Abstract

Disclosed are a method for multi-user transmission and reception in a wireless communication system and a device for same. More particularly, a method for performing multi-user (MU) transmission by a station (STA) device in a wireless communication system comprises the steps of: generating a high efficiency-long training field (HE-LTF) sequence in a frequency domain in accordance with an MU transmission bandwidth; and transmitting a physical protocol data unit (PPDU) which comprises one or more symbols to which the HE-LTF sequence is mapped, wherein the HE-LTF sequence can be generated by multiplying one row of a P matrix to a length unit of a row of the P matrix in a predetermined sequence.

First claim

What is claimed is:

1. A method for performing, by a station (STA) apparatus, multi-user (MU) transmission in a wireless communication system, the method comprising:
generating a physical protocol data unit (PPDU) including a data field and plural signal fields; and
transmitting the PPDU to another STA,
wherein the PPDU further comprises one or more long training field (LTF) symbols for at least one of synchronization or channel estimation,
wherein the LTF symbols are generated based on a LTF sequence that is generated in a frequency domain according to an MU transmission bandwidth by multiplying a predefined sequence with one row of a predefined matrix,
wherein the predefined sequence having a plurality of equal length first parts of the predefined sequence and a second part of the predefined sequence that is remaining part,
wherein the second part of the predefined sequence is shorter than any of the first parts of the predefined sequence,
wherein the LTF sequence comprises a first part of the LTF sequence concatenated with a second part of the LTF sequence,
wherein the first part of the LTF sequence is generated by multiplying the plurality of equal length first parts of the predefined sequence by all elements of the one row of the predefined matrix in order to generate a plurality of concatenated elements,
wherein the predefined matrix is a matrix of M rows and M columns (M=natural number) having orthogonality between each of rows,
wherein the second part of the LTF sequence is generated by multiplying the second part of the predefined sequence by only a subset of the one row of the predefined matrix, the subset of the one row of the predefined matrix consisting of a number of consecutive first elements corresponding a number of elements in the second part of the predefined sequence, and
wherein each row of the predefined matrix multiplied by the predefined sequence is applied to corresponding different STAs.

2. The method of claim 1 , wherein the transmitted LTF sequence consists of non-zero elements of the LTF sequence.

3. The method of claim 1 , wherein the length of the predefined matrix is fixed to 8 regardless of a number of time-spatial streams allocated for the MU transmission.

4. The method of claim 1 , wherein the length of the predefined matrix has a combination of one or more of 2, 4 and 8.

5. The method of claim 1 , wherein the method is used for a carrier frequency offset and channel estimation in a unit of tones multiplied by the one row of the predefined matrix.

6. The method of claim 1 , wherein the method is used for a carrier frequency offset and channel estimation in a unit of tones having specific tone intervals regardless in a unit of tones multiplied by the one row of the predefined matrix.

7. The method of claim 1 , wherein tones for a mapping of the LTF sequence are classified and allocated for each group within the MU transmission bandwidth.

8. The method of claim 7 , wherein the tones for the mapping of the LTF sequence are differently allocated after a number of symbols corresponding to a number of STAs within the group among the one or more LTF symbols.

9. The method of claim 1 , wherein the predefined sequence is multiplied by different rows of the predefined matrix for each time-spatial stream.

10. The method of claim 1 , wherein the predefined matrix is defined by a following equation:

P

8
⨯
8

=

[

P

4
⨯
4

P

4
⨯
4

P

4
⨯
4

-

P

4
⨯
4

]

,

⁢

where
⁢

⁢

P

4
⨯
4

=

[

1

-
1

1

1

1

1

-
1

1

1

1

1

Assignees

• Lg Electronics Inc

Inventors

• Park Eunsung
• Lee Wookbong
• Cho Hangyu

Classifications

• H04L5/0037

  Inter-user or inter-terminal allocation · CPC title

• H04L27/266

  Fine or fractional frequency offset determination and synchronisation · CPC title

• H04L25/0224

  using sounding signals · CPC title

• H04L27/2657 Primary

  Carrier synchronisation · CPC title

• H04L69/324

  in the data link layer [OSI layer 2], e.g. HDLC · CPC title