Method and apparatus for generating STF signal using binary sequence in wireless LAN system

• US 10,320,590 B2
• Filed: 08/05/2016
• Issued: 06/11/2019
• Est. Priority Date: 08/06/2015
• Status: Active Grant

• Current Assignee: LG Electronics, Inc. (LG Corporation)
• Original Assignee: LG Electronics, Inc. (LG Corporation)
• Inventors: Park, Eunsung, Choi, Jinsoo, Cho, Hangyu
• Primary Examiner(s): Nguyen, Steven H
• Application Number:
  US15/516,346
• Publication Number:
  US 20170310506A1
• Time in Patent Office: 1,040 Days
• CPC Class Codes: H04L 1/001 applied to control information
• CPC Class Codes: H04L 1/0031 Multiple signaling transmission H04L1/1664, F15 take precedence
• CPC Class Codes: H04L 25/03 Shaping networks in transmitter or receiver, e.g. adaptive shaping networks
• CPC Class Codes: H04L 27/2613 Structure of the reference signals
• CPC Class Codes: H04L 27/26132 using repetition
• CPC Class Codes: H04L 27/2666 Acquisition of further OFDM parameters, e.g. bandwidth, subcarrier spacing, or guard interval length
• CPC Class Codes: H04L 27/34 Amplitude- and phase-modulated carrier systems, e.g. quadrature-amplitude modulated carrier systems
• CPC Class Codes: H04L 5/0007 the frequencies being orthogonal, e.g. OFDM(A), DMT
• CPC Class Codes: H04L 5/0037 Inter-user or inter-terminal allocation
• CPC Class Codes: H04L 5/0048 Allocation of pilot signals, i.e. of signals known to the receiver
• CPC Class Codes: H04W 84/12 WLAN [Wireless Local Area Networks]

Abstract

Disclosed are a method and an apparatus for generating an STF signal usable in a wireless LAN system. The STF signal is included in a field used to improve AGC estimation of a MIMO transmission. A portion of the STF signal is used to transmit an uplink, and can be used for uplink MU PPDUs transmitted from a plurality of STAs. The STF that is suggested, for example, is used for a 40 MHz band or an 80 MHz band and can be generated based on a sequence in which a predetermined M sequence is repeated. The predetermined M sequence can be a binary sequence of which the length is 15 bits.

Claims

1. A method in a wireless local area network (LAN) system, the method comprising:

selecting, by a transmitting apparatus, a short training field (STF) sequence from a plurality of predetermined sequences, wherein the selected STF sequence includes a predetermined M sequence;

generating, by the transmitting apparatus, an STF signal used for a transmission frequency band based on the selected STF sequence; and

transmitting, by the transmitting apparatus, a physical protocol data unit (PPDU) including the generated STF signal to a receiving apparatus,

wherein the selected STF sequence is defined as shown below;

{M, −

1, M, −

1, −

M, −

1, M, 0, −

M, 1, M, 1, −

M, 1, −

M}*(1+j)/sqrt(2), wherein sqrt( ) denotes a square root, and

wherein the predetermined M sequence is a sequence having a length of 15 bits and is defined as shown below;

M={−

1, −

1, −

1, 1, 1, 1, −

1, 1, 1, 1, −

1, 1, 1, −

1, 1}.

2. The method of claim 1,

wherein the {M, −

1, M, −

1, −

M, −

1, M, 0, −

M, 1, M, 1, −

M, 1, −

M}*(1+j)/sqrt(2) sequence is positioned at intervals of 8 tones starting from a lowest tone having a tone index of −

504 and up to a highest tone having a tone index of +504, and

wherein, elements corresponding to tone indexes −

504 and 504 in the {M, −

1, M, −

1, −

M, −

1, M, 0, −

M, 1, M, 1, −

M, 1, −

M}*(1+j)/sqrt(2) sequence are processed to be null elements.

3. The method of claim 1, wherein the transmitting apparatus selects a first frequency tone interval or a second frequency tone interval, and wherein the transmitting apparatus generates the STF signal based on the selected frequency tone interval.

4. The method of claim 3, wherein, in case the PPDU is an uplink MU PPDU corresponding to a trigger frame received from an access point (AP), the first frequency tone is selected.

5. The method of claim 3, wherein the first frequency tone interval is equal to 8, and wherein the second frequency tone interval is equal to 16.

6. The method of claim 1, wherein the transmission frequency band is an 80 MHz band.

7. The method of claim 1, wherein elements in the STF sequence are defined in a unit of 78.125 kHz.

8. The method of claim 1, wherein the STF sequence is selected by the transmitting apparatus from the plurality of predetermined sequences to improve automatic gain control (AGC) estimation in transmission from the transmitting apparatus.

9. A transmitting apparatus of a wireless local area network (LAN) system, comprising:

a radio frequency (RF) unit transmitting or receiving radio signals; and

a processor controlling the RF unit,

wherein the processor is configured;

to select a short training field (STF) sequence from a plurality of predetermined sequences, wherein the selected STF sequence includes a predetermined M sequence;

to generate an STF signal used for a transmission frequency band based on the selected STF sequence; and

to transmit a physical protocol data unit (PPDU) including the generated STF signal to a receiving apparatus,

wherein the selected STF sequence is defined as shown below;

{M, −

1, M, −

1, −

M, −

1, M, 0, −

M, 1, M, 1, −

M, 1, −

M}*(1+j)/sqrt(2), wherein sqrt( ) denotes a square root, and

wherein the predetermined M sequence is a sequence having a length of 15 bits and is defined as shown below;

M={−

1, −

1, −

1, 1, 1, 1, −

1, 1, 1, 1, −

1, 1, 1, −

1, 1}.

10. The transmitting apparatus of claim 9,

wherein the {M, −

1, M, −

1, −

M, −

1, M, 0, −

M, 1, M, 1, −

M, 1, −

M}*(1+j)/sqrt(2) sequence is positioned at intervals of 8 tones starting from a lowest tone having a tone index of −

504 and up to a highest tone having a tone index of +504, and

wherein, elements corresponding to tone indexes −

504 and 504 in the {M, −

1, M, −

1, −

M, −

1, M, 0, −

M, 1, M, 1, −

M, 1, −

M}*(1+j)/sqrt(2) sequence are processed to be null elements.

11. The transmitting apparatus of claim 9, wherein the transmitting apparatus selects a first frequency tone interval or a second frequency tone interval, and wherein the transmitting apparatus generates the STF signal based on the selected frequency tone interval.

12. The transmitting apparatus of claim 11, wherein, in case the PPDU is an uplink multi user (MU) PPDU corresponding to a trigger frame received from an access point (AP), the first frequency tone is selected.

13. The transmitting apparatus of claim 11, wherein the first frequency tone interval is equal to 8, and wherein the second frequency tone interval is equal to 16.

14. The transmitting apparatus of claim 9, wherein the transmission frequency band is an 80 MHz band.

15. The transmitting apparatus of claim 9, wherein elements in the STF sequence are defined in a unit of 78.125 kHz.

16. The transmitting apparatus of claim 9, wherein the STF sequence is selected by the transmitting apparatus from the plurality of predetermined sequences to improve automatic gain control (AGC) estimation in transmission from the transmitting apparatus.