Technique for transmitting LTF signal in wireless communication system
One embodiment according to the present specification relates to a technique for transmitting a long training field (LTF) signal in a wireless LAN (WLAN) system. The LTF signal may comprise an LTF sequence transmitted on the basis of a plurality of subcarriers. For example, a minimum subcarrier index of a plurality of subcarriers may be set to −28, and a maximum subcarrier index of the plurality of subcarriers may be set to 28. A pilot tone may be inserted/allocated to four subcarriers from among a plurality of subcarriers.
1. A method in a wireless local area network (WLAN) system, the method performed by a transmitting station (STA) and comprising:
generating a Next Generation V2X Physical Protocol Data Unit (NGV PPDU) including a long training field (LTF) signal; and
transmitting the NGV PPDU to a receiving STA,
wherein a bandwidth of the NGV PPDU is 10 MHZ,
wherein the NGV PPDU is transmitted based on a frequency spacing of 156.25 kHz,
wherein the LTF signal is generated based on an LTF sequence configured based on a plurality of subcarriers having the frequency spacing,
wherein a minimum subcarrier index of the plurality of subcarriers is set to ‘−28’,
wherein a maximum subcarrier index of the plurality of subcarriers is set to ‘+28’,
wherein four (4) pilot tones are allocated to the plurality of subcarriers,
wherein subcarrier indices for the four (4) pilot tones are set to −22, −8, +8, and +22, and
wherein the LTF sequence is defined as {1, 0, 1, 0, −1, 0, 1, 0, −1, 0, −1, 0, 1, 0, 1, 0, 1, 0, −1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 0, 0, −1, 0, 1, 0, −1, 0, −1, 0, −1, 0, −1, 0, −1, 0, 1, 0, −1, 0, −1, 0, −1, 0, 1, 0, 1, 0, −1}.
2. The method of claim 1 , wherein a duration of one symbol of the LTF signal is set to 4.8 μs.
3. The method of claim 1 , wherein the LTF signal further includes a Guard Interval (GI), and a duration of the GI is set to 1.6 μs.
4. The method of claim 1 , wherein the NGV PPDU further includes at least one midamble, wherein a first midamble among the at least one midamble is configured to be same as the LTF signal.
5. The method of claim 1 , wherein the NGV PPDU further includes a legacy signal field, a repeated legacy signal field in which the legacy signal field is repeated, an NGV signal field, and a repeated NGV signal field in which the NGV signal field is repeated.
6. The method of claim 5 , wherein the NGV signal field includes information related to the bandwidth of the NGV PPDU and information related to the LTF sequence.
7. The method of claim 1 , wherein the LTF signal is transmitted through subcarriers having an even subcarrier index among the plurality of subcarriers.
8. The method of claim 1 , wherein the LTF signal is used for channel estimation by the receiving STA.
9. The method of claim 1 , wherein the NGV PPDU is transmitted through a 5.9 GHz band.
10. A method in a wireless local area network (WLAN) system, the method performed by a receiving station (STA) and comprising:
receiving a Next Generation V2X Physical Protocol Data Unit (NGV PPDU) including a long training field (LTF) signal,
wherein a bandwidth of the NGV PPDU is 10 MHZ,
wherein the NGV PPDU is transmitted based on a frequency spacing of 156.25 kHz,
wherein the LTF signal is generated based on an LTF sequence configured based on a plurality of subcarriers having the frequency spacing,
wherein a minimum subcarrier index of the plurality of subcarriers is set to ‘−28’,
wherein a maximum subcarrier index of the plurality of subcarriers is set to ‘+28’,
wherein four (4) pilot tones are allocated to the plurality of subcarriers,
wherein subcarrier indices for the four (4) pilot tones are set to −22, −8, +8, and +22, and
wherein the LTF sequence is defined as {1, 0, 1, 0, −1, 0, 1, 0, −1, 0, −1, 0, 1, 0, 1, 0, 1, 0, −1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 0, 0, −1, 0, 1, 0, −1, 0, −1, 0, −1, 0, −1, 0, −1, 0, 1, 0, −1, 0, −1, 0, −1, 0, 1, 0, 1, 0, −1}; and
performing channel estimation based on the LTF signal.
11. A transmitting station (STA) in a wireless local area network (WLAN) system, the STA comprising:
a transceiver configured transmit and/or receive a wireless signal; and
a processor coupled to the transceiver,
wherein the processor is configured to:
generate a Next Generation V2X Physical Protocol Data Unit (NGV PPDU) including a long training field (LTF) signal; and
transmit the NGV PPDU to a receiving STA,
wherein a bandwidth of the NGV PPDU is 10 MHZ,
wherein the NGV PPDU is transmitted based on a frequency spacing of 156.25 kHz,
wherein the LTF signal is generated based on an LTF sequence configured based on a plurality of subcarriers having the frequency spacing,
wherein a minimum subcarrier index of the plurality of subcarriers is set to ‘−28’,
wherein a maximum subcarrier index of the plurality of subcarriers is set to ‘+28’,
wherein four (4) pilot tones are allocated to the plurality of subcarriers,
wherein subcarrier indices for the four (4) pilot tones are set to −22, −8, +8, and +22, and
wherein the LTF sequence is defined as {1, 0, 1, 0, −1, 0, 1, 0, −1, 0, −1, 0, 1, 0, 1, 0, 1, 0, −1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 0, 0, −1, 0, 1, 0, −1, 0, −1, 0, −1, 0, −1, 0, −1, 0, 1, 0, −1, 0, −1, 0, −1, 0, 1, 0, 1, 0, −1}.
12. The STA of claim 11 , wherein a duration of one symbol of the LTF signal is set to 4.8 μs.
13. The STA of claim 11 , wherein the LTF signal further includes a Guard Interval (GI), and a duration of the GI is set to 1.6 μs.
14. The STA of claim 11 , wherein the NGV PPDU further includes at least one midamble, wherein a first midamble among the at least one midamble is configured to be same as the LTF signal.
15. The STA of claim 11 , wherein the NGV PPDU further includes a legacy signal field, a repeated legacy signal field in which the legacy signal field is repeated, an NGV signal field, and a repeated NGV signal field in which the NGV signal field is repeated.