Method for configuring preamble in wireless communication system
One example according to the present specification relates to a technique related to configuration of a preamble in a wireless LAN (WLAN) system. According to various embodiments, a receiving STA may receive an NDP frame. The NDP frame may comprise a first signal field and a second signal field. The first signal field may comprise first information about a PHY version. The second signal field may comprise second information about transmission of a PPDU, set on the basis of the first information. The receiving STA may perform channel sounding on the basis of the NDP frame.
1. A method performed by a station (STA) in a wireless local area network (WLAN) system, the method comprising:
receiving an Extremely High Throughput (EHT) Physical Protocol Data Unit (PPDU),
wherein the EHT PPDU includes a legacy signal (L-SIG) field, a repeated L-SIG field which is a repeat of the L-SIG field, a universal signal (U-SIG) field, an EHT signal (EHT-SIG) field, and an EHT long training field (LTF) signal,
wherein the L-SIG field includes a length field, which is set to a value satisfying a condition that a remainder is zero when the length field is divided by three, and the remainder is used to differentiate the EHT PPDU from a High Efficiency (HE) PPDU,
wherein the U-SIG field includes first information related to a physical layer (PHY) version of the EHT PPDU, the first information has a length of 3 bits, and a value of the first information is used to identify a PHY version starting with EHT,
wherein the U-SIG field further includes 2-bit information indicating whether the EHT PPDU is related to a sounding Null Data PPDU (NDP),
wherein the U-SIG field has a length of two symbols,
wherein the EHT LTF signal is constructed based on an EHT-LTF sequence, and the EHT-LTF sequence for the sounding NDP is a 2×EHT-LTF sequence,
transmitting, based on the EHT PPDU, information related to channel state.
2. The method of claim 1 , wherein the EHT-SIG field includes a common field, and the common field does not include a subfield for resource under (RU) allocation for the sounding NDP.
3. The method of claim 1 , wherein the information related to the channel state includes channel estimation information.
4. The method of claim 1 , wherein the STA is a non-access point STA.
5. The method of claim 1 , wherein the STA is a non-access point STA.
6. The method of claim 1 , wherein the 2×EHT-LTF sequence includes non-zero elements with an interval of 2 sub-carriers.
7. A station (STA) in a wireless local area network (WLAN) system, comprising:
a transceiver configured to transmit and/or receive a wireless signal;
a processor coupled to the transceiver,
wherein the processor is adapted to:
receive an Extremely High Throughput (EHT) Physical Protocol Data Unit (PPDU),
wherein the EHT PPDU includes a legacy signal (L-SIG) field, a repeated L-SIG field which is a repeat of the L-SIG field, a universal signal (U-SIG) field, an EHT signal (EHT-SIG) field, and an EHT long training field (LTF) signal,
wherein the L-SIG field includes a length field, which is set to a value satisfying a condition that a remainder is zero when the length field is divided by three, and the remainder is used to differentiate the EHT PPDU from a High Efficiency (HE) PPDU,
wherein the U-SIG field includes first information related to a physical layer (PHY) version of the EHT PPDU, the first information has a length of 3 bits, and a value of the first information is used to identify a PHY version starting with EHT,
wherein the U-SIG field further includes 2-bit information indicating whether the EHT PPDU is related to a sounding Null Data PPDU (NDP),
wherein the U-SIG field has a length of two symbols, and
wherein the EHT LTF signal is constructed based on an EHT-LTF sequence, and the EHT-LTF sequence for the sounding NDP is a 2×EHT-LTF sequence.
8. The STA of claim 7 , wherein the EHT-SIG field includes a common field, and the common field does not include a subfield for resource under (RU) allocation for the sounding NDP.
9. The STA of claim 7 , wherein the 2×EHT-LTF sequence includes non-zero elements with an interval of 2 sub-carriers.
10. A station (STA) in a wireless local area network (WLAN) system, comprising:
a transceiver configured to transmit and/or receive a wireless signal;
a processor coupled to the transceiver,
wherein the processor is adapted to:
generate an Extremely High Throughput (EHT) Physical Protocol Data Unit (PPDU),
wherein the EHT PPDU includes a legacy signal (L-SIG) field, a repeated L-SIG field which is a repeat of the L-SIG field, a universal signal (U-SIG) field, an EHT signal (EHT-SIG) field, and an EHT long training field (LTF) signal,
wherein the L-SIG field includes a length field, which is set to a value satisfying a condition that a remainder is zero when the length field is divided by three, and the remainder is used to differentiate the EHT PPDU from a High Efficiency (HE) PPDU,
wherein the U-SIG field includes first information related to a physical layer (PHY) version of the EHT PPDU, the first information has a length of 3 bits, and a value of the first information is used to identify a PHY version starting with EHT,
wherein the U-SIG field further includes 2-bit information indicating whether the EHT PPDU is related to a sounding Null Data PPDU (NDP),
wherein the U-SIG field has a length of two symbols, and
wherein the EHT LTF signal is constructed based on an EHT-LTF sequence, and the EHT-LTF sequence for the sounding NDP is a 2×EHT-LTF sequence.
11. The STA of claim 10 , wherein the EHT-SIG field includes a common field, and the common field does not include a subfield for resource under (RU) allocation for the sounding NDP.
12. The STA of claim 10 , wherein the STA is an access point STA.
13. The STA of claim 10 , wherein the sounding NDP is transmitted to a non-access point STA.
14. The STA of claim 10 , wherein the 2×EHT-LTF sequence includes non-zero elements with an interval of 2 sub-carriers.