Data transmission method and apparatus in wireless local area network

• US 10,686,640 B2
• Filed: 05/23/2018
• Issued: 06/16/2020
• Est. Priority Date: 11/23/2015
• Status: Active Grant

• Current Assignee: Huawei Technologies Co., Ltd. (Huawei Investment & Holding Co., Ltd.)
• Original Assignee: Huawei Technologies Co., Ltd. (Huawei Investment & Holding Co., Ltd.)
• Inventors: Lin, Wei, Xue, Xin, Wang, Ningjuan, Liu, Le
• Primary Examiner(s): Renner, Brandon M
• Application Number:
  US15/987,216
• Publication Number:
  US 20180331876A1
• Time in Patent Office: 755 Days
• Field of Search: None
• CPC Class Codes: H04B 7/0452 Multi-user MIMO systems
• CPC Class Codes: H04L 25/022 of frequency response
• CPC Class Codes: H04L 25/0226 sounding signals per se
• CPC Class Codes: H04L 27/2601 Multicarrier modulation systems
• CPC Class Codes: H04L 27/261 Details of reference signals
• CPC Class Codes: H04L 27/2614 Peak power aspects
• CPC Class Codes: H04L 27/2672 Frequency domain
• CPC Class Codes: H04W 24/10 Scheduling measurement reports ; Arrangements for measurement reports
• CPC Class Codes: H04W 72/1268 of uplink data flows
• CPC Class Codes: H04W 72/23 in the downlink direction of a wireless link, i.e. towards a terminal
• CPC Class Codes: H04W 84/12 WLAN [Wireless Local Area Networks]

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.

Claims

1. A channel estimation information transmission method, comprising:

determining, by an apparatus, a high efficiency long training field (HE-LTF) sequence in frequency domain according to a transmission bandwidth and a mode of a HE-LTF field;

sending, by the apparatus, a time-domain signal, according to the determined HE-LTF sequence and a number of orthogonal frequency division multiplexing (OFDM) symbols of the HE-LTF field (N_HELTF);

wherein the HE-LTF sequence in the frequency domain in a 1×

HE-LTF mode over a 160 MHz bandwidth corresponds to;

HE-LTF=[P1×

LTF_{80MHz_Primary},BI, P2×

LTF_{80MHz_Secondary}], wherein P1 is +1, P2 is +1 or 1,

LTF_{80MHz_Primary}={L-LTF_{80MHz_A}, 0, R-LTF_{80MHz_A}},

LTF_{80MHz_Secondary}={L-LTF_{80MHz_A}, 0, −

1×

R-LTF_{80MHz_A}}

and the BI is a sequence carried on a subcarrier between subcarriers on edges of two 80 MHz channels;

wherein {L-LTF_{80MHz_A}, 0, R-LTF_{80MHz_A}}=HE-LTF₂₅₀(−

500;

4;

500), and

2. The method according to claim 1, wherein

the primary 80 MHz (LTF_{80MHz_Primary}) channel and the secondary 80 MHz (LTF_{80MHz_Secondary}) channel in the 160 MHz bandwidth are adjacent, the BI={0, 0, 0, 0, 0}.

3. The method according to claim 1, the method further comprising:

before determining the HE-LTF sequence in 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 HE-LTF symbols.

4. The method according to claim 1, further comprising:

determining, the N_HELTF, based on a total number of space-time streams, N_STS, in a single user transmission, or, a downlink multi-user multiple-input multiple-output (DL-MU-MIMO) transmission, wherein the N_HELTF and the N_STS correspond to;

5. A channel estimation information process method, comprising:

receiving, by an apparatus, a preamble that comprises a high efficiency long training field (HE-LTF);

obtaining, by the apparatus, a channel estimation value of a corresponding subcarrier location, according to the received HE-LTF field and a HE-LTF sequence in a frequency domain,

wherein the HE-LTF sequence in the frequency domain in a lx HE-LTF mode over a 160 MHz bandwidth corresponds to;

HE-LTF=[P1×

LTF_{80MHz_Primary}, BI, P2×

LTF_{80MHz_Secondary}], wherein P1 is +1, P2 is +1 or 1,

LTF_{80MHz_Primary}={L-LTF_{80MHz_A}, 0, R-LTF_{80MHz_A}},

LTF_{80MHz_Secondary}={L-LTF_{80MHz_A}, 0, −

1×

R-LTF_{80MHz_A}}

and the BI is a frequency spacing between subcarriers on edges of two 80 MHz channels;

wherein {L-LTF_{80MHz_A}, 0, R-LTF_{80MHz_A}}=HE-LTF₂₅₀(−

500;

4;

500),

and

6. The method according to claim 5, wherein

when a primary 80 MHz (LTF_{80MHz_Primary}) channel and a secondary 80 MHz (LTF_{80MHz_Secondary}) channel in the 160 MHz bandwidth are adjacent, the BI={0, 0, 0, 0, 0}.

7. The method according to claim 5, further comprising:

before receiving the preamble which comprises the HE-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 HE-LTF symbols.

8. The method according to claim 5, further comprising:

obtaining, by the apparatus, a transmission bandwidth BW, a total number of space-time streams, N_STS, and a mode of a high efficiency long training HE-LTF field, according to information carried in a signal field in the preamble, in a single user transmission or, a downlink multi-user multiple-input multiple-output (DL-MU-MIMO) transmission;

determining, by the apparatus, a number of orthogonal frequency division multiplexing (OFDM) symbols of the HE-LTF field (N_HELTF), based on the total number of space-time streams (N_STS); and

determining, by the receive apparatus, the HE-LTF sequence in frequency domain according to the transmission bandwidth and the mode of the HE-LTF field.

9. A communication apparatus, comprising:

a memory comprising instructions; and

one or more processors in communication with the memory, wherein the one or more processors execute the instructions to;

determine a high efficiency long training field (HE-LTF) sequence in a frequency domain according to a transmission bandwidth and a mode of a HE-LTF field;

send a time-domain signal, according to the determined HE-LTF sequence and a number of orthogonal frequency division multiplexing (OFDM) symbols of the HE-LTF field (N_HELTF);

wherein the HE-LTF sequence in the frequency domain in a 1×

HE-LTF mode over a 160 MHz bandwidth corresponds to;

HE-LTF=[P1×

LTF_{80MHz_Primary}, BI, P2×

LTF_{80MHz_Secondary}], wherein P1 is +1, P2 is +1 or 1,

LTF_{80MHz_Primary}={L-LTF_{80MHz_A}, 0, R-LTF_{80MHz_A}},

LTF_{80MHz_Secondary}={L-LTF_{80MHz_A}, 0, −

1×

R-LTF_{80MHz_A}}

and the BI is a sequence carried on a subcarrier between subcarriers on edges of two 80 MHz channels,

wherein {L-LTF_{80MHz_A}, 0, R-LTF_{80MHz_A}}=HE-LTF₂₅₀(−

500;

4;

500), and

10. The apparatus according to claim 9, wherein

the primary 80 MHz (LTF_{80MHz_Primary}) channel and the secondary 80 MHz (LTF_{80MHz_Secondary}) channel in the 160 MHz bandwidth are adjacent, the BI={0, 0, 0, 0, 0}.

11. The apparatus according to claim 9, wherein the one or more processors execute the instructions further to:

before determine the HE-LTF sequence in the frequency domain, receive 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 HE-LTF symbols.

12. The apparatus according to claim 9, wherein the one or more processors execute the instructions further to:

determine, the N_HELTF, 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 N_HELTF and the N_STS correspond to;

13. A communication apparatus, comprising:

a memory comprising instructions; and

one or more processors in communication with the memory, wherein the one or more processors execute the instructions to;

receive a preamble that comprises a high efficiency long training field (HE-LTF);

obtain a channel estimation value of a corresponding subcarrier location, according to the received HE-LTF field and a HE-LTF sequence in a frequency domain,

wherein the HE-LTF sequence in the frequency domain in a 1×

HE-LTF mode over a 160 MHz bandwidth corresponds to;

HE-LTF=[P1×

LTF_{80MHz_Primary}, BI, P2×

LTF_{80MHz_Secondary}], wherein P1 is +1, P2 is +1 or 1,

LTF_{80MHz_Primary}={L-LTF_{80MHz_A}, 0, R-LTF_{80MHz_A}},

LTF_{80MHz_Secondary}={L-LTF_{80MHz_A}, 0, −

1×

R-LTF_{80MHz_A}}

and the BI is a frequency spacing between subcarriers on edges of two 80 MHz channels,

wherein {L-LTF_{80MHz_A}, 0, R-LTF_{80MHz_A}}=HE-LTF₂₅₀(−

500;

4;

500),

and

14. The apparatus according to claim 13, wherein

when a primary 80 MHz (LTF_{80MHz_Primary}) channel and a secondary 80 MHz (LTF_{80MHz_Secondary}) channel in the 160 MHz bandwidth are adjacent, the BI={0, 0, 0, 0, 0}.

15. The apparatus according to claim 13, wherein the one or more processors execute the instructions further to:

before receive the preamble which comprises the HE-LTF field,

send 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 HE-LTF symbols.

16. The apparatus according to claim 13, wherein the one or more processors execute the instructions further to:

obtain a transmission bandwidth (BW), a total number of space-time streams (N_STS) and a mode of a HE-LTF field, according to information carried in a signal field in the preamble, in a single user transmission, or, in a downlink multi-user multiple-input multiple-output (DL-MU-MIMO) transmission;

determine, a number of orthogonal frequency division multiplexing (OFDM) symbols of the HE-LTF field(N_HELTF), based on the total number of space-time streams (N_STS), and

determine the HE-LTF sequence in frequency domain according to the transmission bandwidth and the mode of the HE-LTF field.