WO2020226416A1 - Constellation rotation for ppdu type classification - Google Patents

Abstract

In a wireless local area network system, a station (STA) may receive a physical protocol data unit (PPDU) including a first legacy training field, a second legacy training field, a legacy control field, and a next generation vehicular network (NGV) training field. The legacy control field may be received via a first symbol, and the NGV training field may be received via a second symbol successive to the first symbol. The first symbol may be modulated based on a first constellation, and the second symbol may be modulated based on a second constellation rotated based on the first constellation. The STA may acquire information on a type of the PPDU on the basis of the first constellation and the second constellation.

Description

Constellation rotation for PPDU type classification

The present specification relates to a method of acquiring information on a physical protocol data unit (PPDU) type in a wireless local area network (LAN) system including a plurality of access points (APs).

Wireless network technologies may include various types of wireless local area networks (WLANs). WLAN employs widely used networking protocols and can be used to interconnect nearby devices together. The various technical features described herein can be applied to any communication standard, such as WiFi or, more generally, any one of the IEEE 802.11 radio protocol family.

This specification improves the existing IEEE 802.11p standard or proposes technical features that can be used in a new communication standard. The new communication standard may be a Next Generation Vehicular (NGV) standard that is currently being discussed.

Meanwhile, in the IEEE standard, various types or formats of PPDU (Physical Protocol Data Unit) have been defined. The transmitting/receiving STA (station) used an auto-detection rule to identify the type/format of the transmitted/received PPDU.

A method performed by a station (STA) in a wireless local area network (LAN) system according to various embodiments may include a technical feature of obtaining information on a PPDU type based on a property of an LTF field. A station (STA) may receive a physical protocol data unit (PPDU) including a first legacy training field, a second legacy training field, a legacy control field, and a next generation vehicular network (NGV) training field. The legacy control field may be received through a first symbol, and the NGV training field may be received through a second symbol successive to the first symbol. The first symbol may be modulated based on a first constellation, and the second symbol may be modulated based on a second constellation rotated based on the first constellation. The STA may obtain information on the type of the PPDU based on the first constellation and the second constellation.

According to an example of the present specification, the receiving STA may know the type of the PPDU (eg, IEEE802.11bd) on the basis of the properties of the NGV training field consecutive to the legacy training field included in the received PPDU. Since a separate signal for packet classification is not generated, overhead can be reduced, and packet classification can be performed quickly.

1 shows an example of a transmitting device and/or a receiving device of the present specification.

2 is a conceptual diagram showing the structure of a wireless LAN (WLAN).

3 is a diagram illustrating a general link setup process.

4 is a diagram showing an example of a PPDU used in the IEEE standard.

5 is a diagram showing an arrangement of resource units (RU) used in a 20 MHz band.

6 is a diagram showing an arrangement of a resource unit (RU) used in a 40 MHz band.

7 is a diagram showing the arrangement of resource units (RU) used in the 80MHz band.

8 shows the structure of the HE-SIG-B field.

9 shows an example in which a plurality of User STAs are allocated to the same RU through the MU-MIMO scheme.

10 shows the operation according to the UL-MU.

11 shows an example of a trigger frame.

12 shows an example of a common information field of a trigger frame.

13 shows an example of a subfield included in a per user information field.

14 describes the technical features of the UORA technique.

15 shows an example of a channel used/supported/defined within a 2.4 GHz band.

16 shows an example of a channel used/supported/defined within a 5 GHz band.

17 shows an example of a channel used/supported/defined within a 6 GHz band.

18 shows an example of a PPDU used in the present specification.

19 shows a modified example of the transmitting device and/or the receiving device of the present specification.

20 shows examples of various types of PPDUs.

21 is a diagram for distinguishing between BPSK and QBPSK.

22 shows a band plan of 5.9GHz DSRC.

23 shows a frame format of a frame according to the 802.11p standard.

24 shows an embodiment of a PPDU format.

25 and 26 are diagrams illustrating an embodiment of a PPDU format.

27 is a diagram showing an embodiment of a PPDU format.

28 is a flowchart illustrating an embodiment of an operation of a receiving STA (station).

29 is a flowchart illustrating an embodiment of a transmitting STA (station) operation.

30 illustrates a vehicle or an autonomous vehicle applied to the present specification.

31 shows an example of a vehicle based on the present specification.

In the present specification, “A or B (A or B)” may mean “only A”, “only B” or “both A and B”. In other words, in the present specification, “A or B (A or B)” may be interpreted as “A and/or B (A and/or B)”. For example, in the present specification, “A, B or C (A, B or C)” refers to “only A”, “only B”, “only C”, or “A, B, and any combination of C ( It can mean any combination of A, B and C)”.

A forward slash (/) or comma used in the present specification may mean "and/or". For example, “A/B” may mean “A and/or B”. Accordingly, “A/B” may mean “only A”, “only B”, or “both A and B”. For example, “A, B, C” may mean “A, B or C”.

In the present specification, “at least one of A and B” may mean “only A”, “only B”, or “both A and B”. In addition, in this specification, the expression “at least one of A or B” or “at least one of A and/or B” means “at least one It can be interpreted the same as "at least one of A and B".

In addition, in the present specification, “at least one of A, B and C” means “only A”, “only B”, “only C”, or “A, B and C Can mean any combination of A, B and C”. In addition, "at least one of A, B or C" or "at least one of A, B and/or C" means It can mean “at least one of A, B and C”.

In addition, parentheses used in the present specification may mean "for example". Specifically, when displayed as “control information (EHT-Signal)”, “EHT-Signal” may be proposed as an example of “control information”. In other words, “control information” of the present specification is not limited to “EHT-Signal”, and “EHT-Signal” may be suggested as an example of “control information”. In addition, even when displayed as “control information (ie, EHT-signal)”, “EHT-signal” may be proposed as an example of “control information”.

In the present specification, technical features that are individually described in one drawing may be implemented individually or simultaneously.

The following example of the present specification can be applied to various wireless communication systems. For example, the following example of the present specification may be applied to a wireless local area network (WLAN) system. For example, this specification can be applied to the IEEE 802.11a/g/n/ac standard or the IEEE 802.11ax standard. In addition, this specification can be applied to the newly proposed EHT standard or IEEE 802.11be standard. In addition, an example of the present specification may be applied to the EHT standard or to a new wireless LAN standard that is improved (enhance) IEEE 802.11be. In addition, an example of the present specification may be applied to a mobile communication system. For example, it can be applied to a mobile communication system based on LTE (Long Term Evolution) based on 3rd Generation Partnership Project (3GPP) standard and its evolution. In addition, an example of the present specification may be applied to a communication system of 5G NR standard based on 3GPP standard.

Hereinafter, in order to describe the technical features of the present specification, technical features to which the present specification can be applied will be described.

1 shows an example of a transmitting device and/or a receiving device of the present specification.

The example of FIG. 1 may perform various technical features described below. 1 is related to at least one STA (station). For example, the STAs 110 and 120 of the present specification include a mobile terminal, a wireless device, a wireless transmit/receive unit (WTRU), a user equipment (UE), It may be referred to by various names such as a mobile station (MS), a mobile subscriber unit, or simply a user. STAs 110 and 120 of the present specification may be referred to by various names such as a network, a base station, a Node-B, an access point (AP), a repeater, a router, and a relay. The STAs 110 and 120 of the present specification may be referred to by various names such as a receiving device, a transmitting device, a receiving STA, a transmitting STA, a receiving device, and a transmitting device.

For example, the STAs 110 and 120 may perform an access point (AP) role or a non-AP role. That is, the STAs 110 and 120 of the present specification may perform AP and/or non-AP functions. In the present specification, the AP may also be indicated as an AP STA.

The STAs 110 and 120 of the present specification may support various communication standards other than the IEEE 802.11 standard together. For example, communication standards (eg, LTE, LTE-A, 5G NR standards) according to 3GPP standards may be supported. In addition, the STA of the present specification may be implemented with various devices such as a mobile phone, a vehicle, and a personal computer. In addition, the STA of the present specification may support communication for various communication services such as voice call, video call, data communication, and autonomous driving (Self-Driving, Autonomous-Driving).

In the present specification, the STAs 110 and 120 may include a medium access control (MAC) and a physical layer interface for a wireless medium according to the IEEE 802.11 standard.

The STAs 110 and 120 will be described on the basis of the sub-drawing (a) of FIG. 1 as follows.

The first STA 110 may include a processor 111, a memory 112, and a transceiver 113. The illustrated processor, memory, and transceiver may each be implemented as separate chips, or at least two or more blocks/functions may be implemented through a single chip.

The transceiver 113 of the first STA performs a signal transmission/reception operation. Specifically, IEEE 802.11 packets (eg, IEEE 802.11a/b/g/n/ac/ax/be, etc.) can be transmitted and received.

For example, the first STA 110 may perform an intended operation of the AP. For example, the processor 111 of the AP may receive a signal through the transceiver 113, process a received signal, generate a transmission signal, and perform control for signal transmission. The memory 112 of the AP may store a signal (ie, a received signal) received through the transceiver 113, and may store a signal (ie, a transmission signal) to be transmitted through the transceiver.

For example, the second STA 120 may perform an intended operation of a non-AP STA. For example, the non-AP transceiver 123 performs a signal transmission/reception operation. Specifically, IEEE 802.11 packets (eg, IEEE 802.11a/b/g/n/ac/ax/be, etc.) can be transmitted and received.

For example, the processor 121 of the non-AP STA may receive a signal through the transceiver 123, process a received signal, generate a transmission signal, and perform control for signal transmission. The memory 122 of the non-AP STA may store a signal (ie, a reception signal) received through the transceiver 123 and may store a signal (ie, a transmission signal) to be transmitted through the transceiver.

For example, in the following specification, an operation of a device indicated as an AP may be performed by the first STA 110 or the second STA 120. For example, when the first STA 110 is an AP, the operation of the device indicated as an AP is controlled by the processor 111 of the first STA 110 and is controlled by the processor 111 of the first STA 110. A related signal may be transmitted or received through the controlled transceiver 113. In addition, control information related to the operation of the AP or a transmission/reception signal of the AP may be stored in the memory 112 of the first STA 110. In addition, when the second STA 110 is an AP, the operation of the device indicated as an AP is controlled by the processor 121 of the second STA 120 and controlled by the processor 121 of the second STA 120. A related signal may be transmitted or received through the transceiver 123 being used. In addition, control information related to the operation of the AP or transmission/reception signals of the AP may be stored in the memory 122 of the second STA 110.

For example, in the following specification, an operation of a device indicated as non-AP (or User-STA) may be performed by the first STA 110 or the second STA 120. For example, when the second STA 120 is a non-AP, the operation of the device marked as non-AP is controlled by the processor 121 of the second STA 120 and the processor of the second STA 120 ( A related signal may be transmitted or received through the transceiver 123 controlled by 121). In addition, control information related to the operation of the non-AP or transmission/reception signals of the AP may be stored in the memory 122 of the second STA 120. For example, when the first STA 110 is a non-AP, the operation of the device indicated as non-AP is controlled by the processor 111 of the first STA 110 and the processor of the first STA 120 ( A related signal may be transmitted or received through the transceiver 113 controlled by 111). In addition, control information related to the operation of the non-AP or transmission/reception signals of the AP may be stored in the memory 112 of the first STA 110.

In the following specification, (transmit/receive) STA, first STA, second STA, STA1, STA2, AP, first AP, second AP, AP1, AP2, (transmit/receive) Terminal, (transmit/receive) device , (Transmission/reception) apparatus, a device called a network, etc. may refer to the STAs 110 and 120 of FIG. 1. For example, without specific reference numerals (transmission/reception) STA, first STA, second STA, STA1, STA2, AP, first AP, second AP, AP1, AP2, (transmission/reception) Terminal, (transmission Devices displayed as /receive) device, (transmit/receive) apparatus, network, etc. may also mean the STAs 110 and 120 of FIG. 1. For example, in the following example, an operation in which various STAs transmit and receive signals (eg, PPPDUs) may be performed by the transceivers 113 and 123 of FIG. 1. In addition, in the following example, an operation in which various STAs generate transmission/reception signals or perform data processing or calculation in advance for transmission/reception signals may be performed by the processors 111 and 121 of FIG. 1. For example, an example of an operation of generating a transmission/reception signal or performing data processing or calculation in advance for a transmission/reception signal is: 1) Determining bit information of a subfield (SIG, STF, LTF, Data) field included in the PPDU. /Acquisition/configuration/computation/decoding/encoding operations, 2) Time resources or frequency resources (eg, subcarrier resources) used for subfields (SIG, STF, LTF, Data) included in the PPDU, etc. Determination/configuration/retrieve operation, 3) A specific sequence used for the subfields (SIG, STF, LTF, Data) fields included in the PPDU (e.g., pilot sequence, STF/LTF sequence, SIG applied An operation of determining/configuring/obtaining an extra sequence), 4) a power control operation and/or a power saving operation applied to the STA, 5) an operation related to determination/acquisition/configuration/calculation/decoding/encoding of an ACK signal, etc. Can include. In addition, in the following example, various information used by various STAs for determination/acquisition/configuration/calculation/decoding/encoding of transmission/reception signals (for example, information related to fields/subfields/control fields/parameters/power, etc.) It may be stored in the memories 112 and 122 of FIG. 1.

The device/STA of the sub-drawing (a) of FIG. 1 described above may be modified as shown in the sub-drawing (b) of FIG. 1. Hereinafter, the STAs 110 and 120 of the present specification will be described based on the sub-drawing (b) of FIG. 1.

For example, the transceivers 113 and 123 illustrated in sub-drawing (b) of FIG. 1 may perform the same functions as the transceiver illustrated in sub-drawing (a) of FIG. 1. For example, the processing chips 114 and 124 shown in sub-drawing (b) of FIG. 1 may include processors 111 and 121 and memories 112 and 122. The processors 111 and 121 and the memories 112 and 122 illustrated in sub-drawing (b) of FIG. 1 are the processors 111 and 121 and the memories 112 and 122 illustrated in sub-drawing (a) of FIG. ) And can perform the same function.

A mobile terminal, a wireless device, a wireless transmit/receive unit (WTRU), a user equipment (UE), a mobile station (MS), and a mobile device described below. Mobile Subscriber Unit, user, user STA, network, base station, Node-B, AP (Access Point), repeater, router, relay, receiving device, transmitting device, receiving STA, transmitting The STA, the receiving device, the transmitting device, the receiving Apparatus, and/or the transmitting Apparatus means the STAs 110 and 120 shown in sub-drawings (a)/(b) of FIG. 1, or the sub-drawing of FIG. 1 (b It may mean the processing chips 114 and 124 shown in ). That is, the technical features of the present specification may be performed on the STAs 110 and 120 shown in sub-drawings (a)/(b) of FIG. 1, and the processing chip shown in sub-drawing (b) of FIG. 114, 124). For example, the technical feature of the transmitting STA transmitting the control signal is that the control signal generated by the processors 111 and 121 shown in sub-drawings (a)/(b) of FIG. 1 is sub-drawing (a) of FIG. It can be understood as a technical feature transmitted through the transceivers 113 and 123 shown in )/(b). Alternatively, the technical feature in which the transmitting STA transmits the control signal is a technical feature in which a control signal to be transmitted to the transceivers 113 and 123 is generated from the processing chips 114 and 124 shown in sub-drawing (b) of FIG. 1. Can be understood.

For example, the technical characteristic that the receiving STA receives the control signal may be understood as a technical characteristic in which the control signal is received by the transceivers 113 and 123 shown in sub-drawing (a) of FIG. 1. Alternatively, the technical feature that the receiving STA receives the control signal is that the control signal received by the transceivers 113 and 123 shown in sub-drawing (a) of FIG. 1 is the processor shown in sub-drawing (a) of FIG. 111, 121) can be understood as a technical feature obtained. Alternatively, the technical feature that the receiving STA receives the control signal is that the control signal received by the transceivers 113 and 123 shown in sub-drawing (b) of FIG. 1 is a processing chip shown in sub-drawing (b) of FIG. It can be understood as a technical feature obtained by (114, 124).

Referring to sub-drawing (b) of FIG. 1, software codes 115 and 125 may be included in the memories 112 and 122. The software codes 115 and 125 may include instructions for controlling the operations of the processors 111 and 121. The software codes 115 and 125 may be included in various programming languages.

The processors 111 and 121 or the processing chips 114 and 124 illustrated in FIG. 1 may include an application-specific integrated circuit (ASIC), another chipset, a logic circuit, and/or a data processing device. The processor may be an application processor (AP). For example, the processors 111 and 121 or the processing chips 114 and 124 shown in FIG. 1 are a digital signal processor (DSP), a central processing unit (CPU), a graphics processing unit (GPU), and a modem (modulator). and demodulator). For example, the processors 111 and 121 or the processing chips 114 and 124 shown in FIG. 1 are SNAPDRAGONTM series processors manufactured by Qualcomm®, EXYNOSTM series processors manufactured by Samsung®, and It may be an A series processor, a HELIOTM series processor manufactured by MediaTek®, an ATOMTM series processor manufactured by INTEL®, or an enhanced processor thereof.

In the present specification, uplink may mean a link for communication from a non-AP STA to an AP STA, and an uplink PPDU/packet/signal may be transmitted through the uplink. In addition, in this specification, the downlink may mean a link for communication from an AP STA to a non-AP STA, and a downlink PPDU/packet/signal may be transmitted through the downlink.

2 is a conceptual diagram showing the structure of a wireless LAN (WLAN).

The upper part of FIG. 2 shows the structure of an infrastructure BSS (basic service set) of IEEE (institute of electrical and electronic engineers) 802.11.

Referring to the upper part of FIG. 2, the wireless LAN system may include one or more infrastructure BSSs 200 and 205 (hereinafter, BSS). The BSS (200, 205) is a set of APs and STAs such as an access point (AP) 225 and STA1 (Station, 200-1) that can communicate with each other by successfully synchronizing, and does not indicate a specific area. The BSS 205 may include one or more STAs 205-1 and 205-2 that can be coupled to one AP 230.

The BSS may include at least one STA, APs 225 and 230 providing a distribution service, and a distribution system (DS) 210 connecting a plurality of APs.

The distributed system 210 may implement an extended service set (ESS) 240, which is an extended service set, by connecting several BSSs 200 and 205. The ESS 240 may be used as a term indicating one network formed by connecting one or several APs through the distributed system 210. APs included in one ESS 240 may have the same service set identification (SSID).

The portal 220 may serve as a bridge for connecting a wireless LAN network (IEEE 802.11) and another network (eg, 802.X).

In the BSS as shown in the upper part of FIG. 2, a network between the APs 225 and 230 and a network between the APs 225 and 230 and the STAs 200-1, 205-1 and 205-2 may be implemented. However, it may be possible to perform communication by setting up a network even between STAs without the APs 225 and 230. A network that performs communication by configuring a network even between STAs without the APs 225 and 230 is defined as an ad-hoc network or an independent basic service set (IBSS).

The lower part of FIG. 2 is a conceptual diagram showing IBSS.

2, the IBSS is a BSS operating in an ad-hoc mode. Since IBSS does not include APs, there is no centralized management entity. That is, in the IBSS, the STAs 250-1, 250-2, 250-3, 255-4, and 255-5 are managed in a distributed manner. In IBSS, all STAs (250-1, 250-2, 250-3, 255-4, 255-5) can be configured as mobile STAs, and access to the distributed system is not allowed, so a self-contained network. network).

3 is a diagram illustrating a general link setup process.

In the illustrated step S310, the STA may perform a network discovery operation. The network discovery operation may include a scanning operation of the STA. That is, in order for the STA to access the network, it must find a network that can participate. The STA must identify a compatible network before participating in the wireless network. The process of identifying a network existing in a specific area is called scanning. Scanning methods include active scanning and passive scanning.

3 illustrates an example of a network discovery operation including an active scanning process. In active scanning, the STA performing scanning transmits a probe request frame to search for an AP present in the vicinity while moving channels and waits for a response thereto. The responder transmits a probe response frame in response to the probe request frame to the STA that has transmitted the probe request frame. Here, the responder may be an STA that last transmitted a beacon frame in the BSS of the channel being scanned. In BSS, since the AP transmits a beacon frame, the AP becomes a responder, and in IBSS, the responder is not constant because STAs in the IBSS rotate and transmit beacon frames. For example, an STA that transmits a probe request frame on channel 1 and receives a probe response frame on channel 1 stores BSS-related information included in the received probe response frame and stores the next channel (e.g., 2 Channel) and scanning (that is, probe request/response transmission/reception on channel 2) in the same manner.

Although not shown in the example of FIG. 3, the scanning operation may be performed in a passive scanning method. An STA performing scanning based on passive scanning may wait for a beacon frame while moving channels. The beacon frame is one of the management frames in IEEE 802.11, and is periodically transmitted so that an STA that notifies the existence of a wireless network and performs scanning can find a wireless network and participate in the wireless network. In the BSS, the AP performs a role of periodically transmitting a beacon frame, and in IBSS, the STAs in the IBSS rotate and transmit the beacon frame. When the STA performing the scanning receives the beacon frame, it stores information on the BSS included in the beacon frame, moves to another channel, and records the beacon frame information in each channel. The STA receiving the beacon frame may store BSS-related information included in the received beacon frame, move to the next channel, and perform scanning in the next channel in the same manner.

The STA that discovers the network may perform an authentication process through step S320. This authentication process may be referred to as a first authentication process in order to clearly distinguish it from the security setup operation of step S340 to be described later. The authentication process of S320 may include a process in which the STA transmits an authentication request frame to the AP, and in response thereto, the AP transmits an authentication response frame to the STA. An authentication frame used for authentication request/response corresponds to a management frame.

The authentication frame consists of an authentication algorithm number, an authentication transaction sequence number, a status code, a challenge text, a robust security network (RSN), and a finite cycle group. Group), etc. can be included.

The STA may transmit an authentication request frame to the AP. The AP may determine whether to allow authentication for the corresponding STA based on the information included in the received authentication request frame. The AP may provide the result of the authentication process to the STA through the authentication response frame.

The STA that has been successfully authenticated may perform a connection process based on step S330. The association process includes a process in which the STA transmits an association request frame to the AP, and in response thereto, the AP transmits an association response frame to the STA. For example, the connection request frame includes information related to various capabilities, beacon listening intervals, service set identifiers (SSIDs), supported rates, supported channels, RSNs, and mobility domains. , Supported operating classes, TIM broadcast request, interworking service capability, and the like may be included. For example, the connection response frame includes information related to various capabilities, status codes, association IDs (AIDs), support rates, Enhanced Distributed Channel Access (EDCA) parameter sets, Received Channel Power Indicators (RCPI), Received Signal to Noise (RSNI). Indicator), mobility domain, timeout interval (association comeback time), overlapping BSS scan parameter, TIM broadcast response, QoS map, etc. may be included.

Thereafter, in step S340, the STA may perform a security setup process. The security setup process of step S340 may include, for example, a process of performing a private key setup through 4-way handshaking through an Extensible Authentication Protocol over LAN (EAPOL) frame. .

4 is a diagram showing an example of a PPDU used in the IEEE standard.

As shown, in standards such as IEEE a/g/n/ac, various types of PHY protocol data units (PPDUs) were used. Specifically, the LTF and STF fields included training signals, SIG-A and SIG-B included control information for the receiving station, and the data field included user data corresponding to PSDU (MAC PDU/Aggregated MAC PDU). Included.

In addition, FIG. 4 also includes an example of an HE PPDU of the IEEE 802.11ax standard. The HE PPDU according to FIG. 4 is an example of a PPDU for multiple users, and HE-SIG-B is included only for multiple users, and the corresponding HE-SIG-B may be omitted in the PPDU for a single user.

As shown, the HE-PPDU for multiple users (MU) is L-STF (legacy-short training field), L-LTF (legacy-long training field), L-SIG (legacy-signal), HE-SIG-A (high efficiency-signal A), HE-SIG-B (high efficiency-signal-B), HE-STF (high efficiency-short training field), HE-LTF (high efficiency-long training field) , A data field (or MAC payload), and a packet extension (PE) field. Each field may be transmitted during the illustrated time period (ie, 4 or 8 μs, etc.).

Hereinafter, a resource unit (RU) used in the PPDU will be described. The resource unit may include a plurality of subcarriers (or tones). The resource unit may be used when transmitting signals to multiple STAs based on the OFDMA technique. Also, even when a signal is transmitted to one STA, a resource unit may be defined. The resource unit can be used for STF, LTF, data fields, and the like.

5 is a diagram showing an arrangement of resource units (RU) used in a 20 MHz band.

As shown in FIG. 5, resource units (RUs) corresponding to different numbers of tones (ie, subcarriers) may be used to configure some fields of the HE-PPDU. For example, resources may be allocated in units of RU shown for HE-STF, HE-LTF, and data fields.

As shown at the top of Fig. 5, 26-units (ie, units corresponding to 26 tones) may be arranged. In the leftmost band of the 20MHz band, 6 tones may be used as a guard band, and in the rightmost band of the 20MHz band, 5 tones may be used as the guard band. In addition, 7 DC tones are inserted in the center band, that is, the DC band, and 26-units corresponding to 13 tones may exist on the left and right sides of the DC band. In addition, 26-units, 52-units, and 106-units may be allocated to other bands. Each unit can be assigned for a receiving station, i.e. a user.

Meanwhile, the RU arrangement of FIG. 5 is utilized not only in a situation for a plurality of users (MU), but also in a situation for a single user (SU). In this case, as shown in the bottom of FIG. 5, one 242-unit is used. It is possible to use and in this case 3 DC tones can be inserted.

In the example of FIG. 5, RUs of various sizes, that is, 26-RU, 52-RU, 106-RU, 242-RU, etc., have been proposed. Since the specific size of these RUs can be expanded or increased, this embodiment Is not limited to the specific size of each RU (ie, the number of corresponding tones).

6 is a diagram showing an arrangement of a resource unit (RU) used in a 40 MHz band.

Similar to the use of RUs of various sizes in the example of FIG. 5, 26-RU, 52-RU, 106-RU, 242-RU, 484-RU, and the like may also be used in the example of FIG. 6. In addition, 5 DC tones can be inserted into the center frequency, 12 tones are used as guard bands in the leftmost band of the 40MHz band, and 11 tones are used in the rightmost band of the 40MHz band. It can be used as a guard band.

Also, as shown, when used for a single user, a 484-RU may be used. Meanwhile, the fact that the specific number of RUs can be changed is the same as the example of FIG. 4.

7 is a diagram showing the arrangement of resource units (RU) used in the 80MHz band.

Similar to the use of RUs of various sizes in the examples of FIGS. 5 and 6, the example of FIG. 7 may also be used with 26-RU, 52-RU, 106-RU, 242-RU, 484-RU, 996-RU, etc. have. In addition, 7 DC tones can be inserted into the center frequency, 12 tones are used as guard bands in the leftmost band of the 80MHz band, and 11 tones are used in the rightmost band of the 80MHz band. It can be used as a guard band. In addition, 26-RU using 13 tones located on the left and right of the DC band can be used.

In addition, as shown, when used for a single user, a 996-RU may be used, and in this case, five DC tones may be inserted.

On the other hand, the fact that the specific number of RUs can be changed is the same as the examples of FIGS. 5 and 6.

The RU arrangement (ie, RU location) shown in FIGS. 5 to 7 can be applied to a new wireless LAN system (eg, EHT system) as it is. On the other hand, in the 160 MHz band supported by the new WLAN system, the RU arrangement for 80 MHz (that is, the example of FIG. 7) is repeated twice or the RU arrangement for the 40 MHz (that is, the example of FIG. 6) is 4 times. Can be repeated. In addition, when the EHT PPDU is configured in the 320 MHz band, the arrangement of the RU for 80 MHz (example of FIG. 7) may be repeated 4 times or the arrangement of the RU for 40 MHz (ie, example of FIG. 6) may be repeated 8 times. have.

One RU of the present specification may be allocated for only one STA (eg, non-AP). Alternatively, a plurality of RUs may be allocated for one STA (eg, non-AP).

The RU described herein may be used for UL (Uplink) communication and DL (Downlink) communication. For example, when UL-MU communication solicited by the trigger frame is performed, the transmitting STA (eg, AP) transmits the first RU (eg, 26/52/106) to the first STA through the trigger frame. /242-RU, etc.), and a second RU (eg, 26/52/106/242-RU, etc.) may be allocated to the second STA. Thereafter, the first STA may transmit a first Trigger-based PPDU based on the first RU, and the second STA may transmit a second Trigger-based PPDU based on the second RU. The first/second Trigger-based PPDU is transmitted to the AP in the same time interval.

For example, when a DL MU PPDU is configured, the transmitting STA (eg, AP) allocates a first RU (eg, 26/52/106/242-RU, etc.) to the first STA, and 2 STAs may be assigned a second RU (eg, 26/52/106/242-RU, etc.). That is, the transmitting STA (eg, AP) may transmit the HE-STF, HE-LTF, and Data fields for the first STA through the first RU within one MU PPDU, and the second RU through the second RU. HE-STF, HE-LTF, and Data fields for 2 STAs can be transmitted.

Information on the arrangement of the RU may be signaled through HE-SIG-B.

8 shows the structure of the HE-SIG-B field.

As shown, the HE-SIG-B field 810 includes a common field 820 and a user-specific field 830. The common field 820 may include information commonly applied to all users (ie, user STAs) receiving the SIG-B. The user-individual field 830 may be referred to as a user-individual control field. When the SIG-B is transmitted to a plurality of users, the user-individual field 830 may be applied to only some of the plurality of users.

As shown in FIG. 8, the common field 920 and the user-individual field 930 may be encoded separately.

The common field 920 may include RU allocation information of N*8 bits. For example, the RU allocation information may include information on the location of the RU. For example, when a 20 MHz channel is used as shown in FIG. 5, the RU allocation information may include information on which RU (26-RU/52-RU/106-RU) is allocated in which frequency band. .

An example of a case in which RU allocation information is composed of 8 bits is as follows.

As in the example of FIG. 5, a maximum of 9 26-RUs may be allocated to a 20 MHz channel. As shown in Table 8, when the RU allocation information of the common field 820 is set to “00000000”, nine 26-RUs may be allocated to a corresponding channel (ie, 20 MHz). In addition, as shown in Table 1, when the RU allocation information of the common field 820 is set to "00000001", seven 26-RUs and one 52-RU are arranged in a corresponding channel. That is, in the example of FIG. 5, 52-RUs may be allocated to the rightmost side and seven 26-RUs may be allocated to the left side.

An example of Table 1 shows only some of the RU locations that can be displayed by RU allocation information.

For example, RU allocation information may include an example of Table 2 below.

"01000y2y1y0" relates to an example in which 106-RU is allocated to the leftmost-left side of a 20 MHz channel, and five 26-RUs are allocated to the right side. In this case, a plurality of STAs (eg, User-STAs) may be allocated to the 106-RU based on the MU-MIMO technique. Specifically, up to 8 STAs (eg, User-STA) may be allocated to 106-RU, and the number of STAs (eg, User-STA) allocated to 106-RU is 3-bit information (y2y1y0). ). For example, when 3-bit information (y2y1y0) is set to N, the number of STAs (eg, User-STAs) allocated to 106-RU based on the MU-MIMO technique may be N+1.

In general, a plurality of different STAs (eg, user STAs) may be allocated to a plurality of RUs. However, for one RU of a specific size (eg, 106 subcarriers) or more, a plurality of STAs (eg, user STAs) may be allocated based on the MU-MIMO technique.

As shown in FIG. 8, the user-individual field 830 may include a plurality of user fields. As described above, the number of STAs (eg, user STAs) allocated to a specific channel may be determined based on the RU allocation information in the common field 820. For example, when the RU allocation information of the common field 820 is "00000000", one User STA may be allocated to each of nine 26-RUs (ie, a total of 9 User STAs are allocated). That is, up to 9 User STAs may be allocated to a specific channel through the OFDMA scheme. In other words, up to 9 User STAs may be allocated to a specific channel through a non-MU-MIMO scheme.

For example, when RU allocation is set to “01000y2y1y0”, a plurality of User STAs are allocated to 106-RUs disposed on the leftmost-left through the MU-MIMO scheme, and five 26-RUs disposed on the right side are allocated Five User STAs may be allocated through a non-MU-MIMO scheme. This case is embodied through an example of FIG. 9.

9 shows an example in which a plurality of User STAs are allocated to the same RU through the MU-MIMO scheme.

For example, when RU allocation is set to “01000010” as shown in FIG. 9, based on Table 2, 106-RUs are allocated to the leftmost-left side of a specific channel, and five 26-RUs are allocated to the right side. I can. In addition, a total of three User STAs may be allocated to the 106-RU through the MU-MIMO scheme. As a result, since a total of 8 User STAs are allocated, the user-individual field 830 of HE-SIG-B may include 8 User fields.

Eight User fields may be included in the order shown in FIG. 9. In addition, as shown in FIG. 8, two User fields may be implemented as one User block field.

The User field shown in FIGS. 8 and 9 may be configured based on two formats. That is, a User field related to the MU-MIMO technique may be configured in a first format, and a User field related to the non-MU-MIMO technique may be configured in a second format. Referring to the example of FIG. 9, User fields 1 to 3 may be based on a first format, and User fields 4 to 8 may be based on a second format. The first format or the second format may include bit information of the same length (eg, 21 bits).

Each User field may have the same size (eg, 21 bits). For example, the User Field of the first format (the format of the MU-MIMO scheme) may be configured as follows.

For example, the first bit (eg, B0-B10) in the user field (ie, 21 bits) is the identification information of the user STA to which the corresponding user field is allocated (eg, STA-ID, partial AID, etc.) It may include. In addition, the second bit (eg, B11-B14) in the user field (ie, 21 bits) may include information on spatial configuration. Specifically, an example of the second bit (ie, B11-B14) may be as shown in Tables 3 to 4 below.

As shown in Table 3 and/or Table 4, the second bit (i.e., B11-B14) may include information on the number of Spatial Streams allocated to a plurality of User STAs allocated according to the MU-MIMO scheme. have. For example, when three User STAs are allocated to 106-RU based on the MU-MIMO scheme as shown in FIG. 9, N_user is set to 3, and accordingly, N_STS[1] and N_STS[ 2], a value of N_STS[3] may be determined. For example, when the value of the second bit (B11-B14) is 0011, it may be set as N_STS[1]=4, N_STS[2]=1, and N_STS[3]=1. That is, in the example of FIG. 9, 4 Spatial Streams may be allocated to User field 1, 1 Spatial Stream may be allocated to User field 2, and 1 Spatial Stream may be allocated to User field 3.

As in the example of Table 3 and/or Table 4, information on the number of spatial streams for a user STA (that is, the second bit, B11-B14) may consist of 4 bits. In addition, information on the number of spatial streams for a user STA (ie, second bits, B11-B14) may support up to eight spatial streams. In addition, information on the number of spatial streams (ie, second bits, B11-B14) may support up to 4 spatial streams for one user STA.

In addition, the third bit (ie, B15-18) in the user field (ie, 21 bits) may include MCS (Modulation and coding scheme) information. MCS information may be applied to a data field in a PPDU in which the corresponding SIG-B is included.

MCS, MCS information, MCS index, MCS field, and the like used in the present specification may be indicated by a specific index value. For example, MCS information may be indicated by index 0 to index 11. The MCS information includes information on a constellation modulation type (e.g., BPSK, QPSK, 16-QAM, 64-QAM, 256-QAM, 1024-QAM, etc.), and a coding rate (e.g., 1/2, 2/ 3, 3/4, 5/6, etc.). Information on the channel coding type (eg, BCC or LDPC) may be excluded from the MCS information.

In addition, the fourth bit (ie, B19) in the user field (ie, 21 bits) may be a reserved field.

In addition, the fifth bit (ie, B20) in the user field (ie, 21 bits) may include information on the coding type (eg, BCC or LDPC). That is, the fifth bit (ie, B20) may include information on the type of channel coding (eg, BCC or LDPC) applied to the data field in the PPDU including the corresponding SIG-B.

The above-described example relates to the User Field of the first format (the format of the MU-MIMO scheme). An example of the User field of the second format (non-MU-MIMO format) is as follows.

The first bit (eg, B0-B10) in the User field of the second format may include identification information of the User STA. In addition, the second bit (eg, B11-B13) in the user field of the second format may include information on the number of spatial streams applied to the corresponding RU. In addition, the third bit (eg, B14) in the user field of the second format may include information on whether the beamforming steering matrix is applied. The fourth bit (eg, B15-B18) in the User field of the second format may include MCS (Modulation and Coding Scheme) information. In addition, the fifth bit (eg, B19) in the User field of the second format may include information on whether or not Dual Carrier Modulation (DCM) is applied. In addition, the sixth bit (ie, B20) in the user field of the second format may include information on the coding type (eg, BCC or LDPC).

10 shows the operation according to the UL-MU. As shown, a transmitting STA (eg, an AP) may perform channel access through contending (ie, a backoff operation) and transmit a trigger frame 1030. That is, the transmitting STA (eg, AP) may transmit a PPDU including the trigger frame 1330. When a PPDU including a trigger frame is received, a trigger-based (TB) PPDU is transmitted after a delay equal to SIFS.

The TB PPDUs 1041 and 1042 may be transmitted at the same time slot and may be transmitted from a plurality of STAs (eg, User STAs) in which an AID is indicated in the trigger frame 1030. The ACK frame 1050 for the TB PPDU may be implemented in various forms.

Specific characteristics of the trigger frame will be described with reference to FIGS. 11 to 13. Even when UL-MU communication is used, an orthogonal frequency division multiple access (OFDMA) technique or an MU MIMO technique can be used, and an OFDMA and MU MIMO technique can be used simultaneously.

11 shows an example of a trigger frame. The trigger frame of FIG. 11 allocates resources for uplink multiple-user transmission (MU), and may be transmitted from an AP, for example. The trigger frame may be composed of a MAC frame and may be included in a PPDU.

Each of the fields shown in FIG. 11 may be partially omitted, and other fields may be added. Also, the length of each field may be changed differently from that shown.

The frame control field 1110 of FIG. 11 includes information on the version of the MAC protocol and other additional control information, and the duration field 1120 is time information for setting NAV or an identifier of the STA (for example, For example, information on AID) may be included.

In addition, the RA field 1130 includes address information of the receiving STA of the corresponding trigger frame, and may be omitted if necessary. The TA field 1140 includes address information of an STA (eg, an AP) that transmits a corresponding trigger frame, and a common information field 1150 is a common information applied to a receiving STA receiving a corresponding trigger frame. Contains control information. For example, a field indicating the length of an L-SIG field of an uplink PPDU transmitted in response to a corresponding trigger frame, or a SIG-A field of an uplink PPDU transmitted in response to a corresponding trigger frame (i.e., HE-SIG-A Field) may contain information that controls the content. In addition, as common control information, information about a length of a CP of an uplink PPDU transmitted in response to a corresponding trigger frame or information about a length of an LTF field may be included.

In addition, it is preferable to include individual user information fields 1160#1 to 1160#N corresponding to the number of receiving STAs receiving the trigger frame of FIG. 11. The individual user information field may be referred to as an assignment field.

In addition, the trigger frame of FIG. 11 may include a padding field 1170 and a frame check sequence field 1180.

Each of the individual user information fields 1160#1 to 1160#N shown in FIG. 11 may again include a plurality of subfields.

12 shows an example of a common information field of a trigger frame. Some of the subfields of FIG. 12 may be omitted, and other subfields may be added. In addition, the length of each of the illustrated subfields may be changed.

The illustrated length field 1210 has the same value as the length field of the L-SIG field of the uplink PPDU transmitted in response to the corresponding trigger frame, and the length field of the L-SIG field of the uplink PPDU represents the length of the uplink PPDU. As a result, the length field 1210 of the trigger frame may be used to indicate the length of the corresponding uplink PPDU.

Also, the cascade indicator field 1220 indicates whether a cascade operation is performed. The cascade operation means that downlink MU transmission and uplink MU transmission are performed together in the same TXOP. That is, after downlink MU transmission is performed, it means that uplink MU transmission is performed after a preset time (eg, SIFS). During a casecade operation, there may be only one transmission device (eg, AP) performing downlink communication, and a plurality of transmission devices (eg, non-AP) performing uplink communication may exist.

The CS request field 1230 indicates whether to consider the state of the radio medium or the NAV in a situation in which the receiving device receiving the corresponding trigger frame transmits the corresponding uplink PPDU.

The HE-SIG-A information field 1240 may include information for controlling the content of the SIG-A field (ie, the HE-SIG-A field) of the uplink PPDU transmitted in response to the corresponding trigger frame.

The CP and LTF type field 1250 may include information on the length of the LTF and the CP length of the uplink PPDU transmitted in response to the corresponding trigger frame. The trigger type field 1060 may indicate a purpose for which the corresponding trigger frame is used, for example, normal triggering, triggering for beamforming, and request for Block ACK/NACK.

In this specification, it may be assumed that the trigger type field 1260 of the trigger frame indicates a basic type of trigger frame for normal triggering. For example, a basic type trigger frame may be referred to as a basic trigger frame.

13 shows an example of a subfield included in a per user information field. The user information field 1300 of FIG. 13 may be understood as any of the individual user information fields 1160#1 to 1160#N mentioned in FIG. 11 above. Some of the subfields included in the user information field 1300 of FIG. 13 may be omitted, and other subfields may be added. In addition, the length of each of the illustrated subfields may be changed.

A user identifier field 1310 of FIG. 13 indicates an identifier of an STA (ie, a receiving STA) corresponding to per user information, and an example of the identifier is an association identifier (AID) of the receiving STA. It can be all or part of the value.

In addition, an RU Allocation field 1320 may be included. That is, when the receiving STA identified by the user identifier field 1310 transmits the TB PPDU corresponding to the trigger frame, it transmits the TB PPDU through the RU indicated by the RU allocation field 1320. In this case, the RU indicated by the RU Allocation field 1320 may be the RU shown in FIGS. 5, 6, and 7.

The subfield of FIG. 13 may include a coding type field 1330. The coding type field 1330 may indicate the coding type of the TB PPDU. For example, when BCC coding is applied to the TB PPDU, the coding type field 1330 may be set to '1', and when LDPC coding is applied, the coding type field 1330 may be set to '0'. have.

In addition, the subfield of FIG. 13 may include an MCS field 1340. The MCS field 1340 may indicate an MCS scheme applied to a TB PPDU. For example, when BCC coding is applied to the TB PPDU, the coding type field 1330 may be set to '1', and when LDPC coding is applied, the coding type field 1330 may be set to '0'. have.

Hereinafter, a UL OFDMA-based Random Access (UORA) technique will be described.

14 describes the technical features of the UORA technique.

The transmitting STA (eg, AP) may allocate 6 RU resources as shown in FIG. 14 through a trigger frame. Specifically, the AP is a first RU resource (AID 0, RU 1), a second RU resource (AID 0, RU 2), a third RU resource (AID 0, RU 3), a fourth RU resource (AID 2045, RU 4), a fifth RU resource (AID 2045, RU 5), and a sixth RU resource (AID 3, RU 6) may be allocated. Information on AID 0, AID 3, or AID 2045 may be included, for example, in the user identification field 1310 of FIG. 13. Information about RU 1 to RU 6 may be included in, for example, the RU allocation field 1320 of FIG. 13. AID=0 may mean a UORA resource for an associated STA, and AID=2045 may mean a UORA resource for an un-associated STA. Accordingly, the first to third RU resources of FIG. 14 may be used as UORA resources for an associated STA, and the fourth to fifth RU resources of FIG. 14 are for un-associated STAs. It may be used as a UORA resource, and the sixth RU resource of FIG. 14 may be used as a resource for a normal UL MU.

In the example of FIG. 14, the OBO (OFDMA random access BackOff) counter of STA1 is reduced to 0, and STA1 randomly selects the second RU resources (AID 0, RU 2). In addition, since the OBO counter of STA2/3 is greater than 0, uplink resources are not allocated to STA2/3. In addition, since STA4 in FIG. 14 includes its AID (ie, AID=3) in the trigger frame, resources of RU 6 are allocated without backoff.

Specifically, since STA1 of FIG. 14 is an associated STA, there are a total of three eligible RA RUs for STA1 (RU 1, RU 2, RU 3), and accordingly, STA1 decreases the OBO counter by 3 so that the OBO counter is It became 0. In addition, since STA2 of FIG. 14 is an associated STA, there are a total of three eligible RA RUs for STA2 (RU 1, RU 2, and RU 3). Accordingly, STA2 has reduced the OBO counter by 3, but the OBO counter is 0. Is in a larger state. In addition, since STA3 of FIG. 14 is an un-associated STA, there are a total of two eligible RA RUs (RU 4 and RU 5) for STA3, and accordingly, STA3 has reduced the OBO counter by 2, but the OBO counter is It is a state greater than 0.

15 shows an example of a channel used/supported/defined within a 2.4 GHz band.

The 2.4 GHz band may be referred to by other names such as the first band (band). In addition, the 2.4 GHz band may refer to a frequency region in which channels having a center frequency adjacent to 2.4 GHz (eg, channels having a center frequency located within 2.4 to 2.5 GHz) are used/supported/defined.

The 2.4 GHz band may contain multiple 20 MHz channels. 20 MHz in the 2.4 GHz band may have multiple channel indexes (eg, index 1 to index 14). For example, a center frequency of a 20 MHz channel to which channel index 1 is assigned may be 2.412 GHz, a center frequency of a 20 MHz channel to which channel index 2 is assigned may be 2.417 GHz, and 20 MHz to which channel index N is assigned The center frequency of the channel may be (2.407 + 0.005*N) GHz. The channel index may be referred to by various names such as channel number. Specific values of the channel index and the center frequency may be changed.

15 exemplarily shows four channels in a 2.4 GHz band. Each of the illustrated first to fourth frequency regions 1510 to 1540 may include one channel. For example, the first frequency domain 1510 may include channel 1 (a 20 MHz channel having index 1). At this time, the center frequency of channel 1 may be set to 2412 MHz. The second frequency domain 1520 may include channel 6. At this time, the center frequency of channel 6 may be set to 2437 MHz. The third frequency domain 1530 may include channel 11. At this time, the center frequency of channel 11 may be set to 2462 MHz. The fourth frequency domain 1540 may include channel 14. At this time, the center frequency of channel 14 may be set to 2484 MHz.

16 shows an example of a channel used/supported/defined within a 5 GHz band.

The 5 GHz band may be referred to by another name such as the second band/band. The 5 GHz band may mean a frequency range in which channels having a center frequency of 5 GHz or more and less than 6 GHz (or less than 5.9 GHz) are used/supported/defined. Alternatively, the 5 GHz band may include a plurality of channels between 4.5 GHz and 5.5 GHz. The specific values shown in FIG. 16 may be changed.

The plurality of channels in the 5 GHz band include UNII (Unlicensed National Information Infrastructure)-1, UNII-2, UNII-3, and ISM. UNII-1 can be called UNII Low. UNII-2 may include a frequency domain called UNII Mid and UNII-2 Extended. UNII-3 can be called UNII-Upper.

A plurality of channels may be set within the 5 GHz band, and the bandwidth of each channel may be variously set to 20 MHz, 40 MHz, 80 MHz, or 160 MHz. For example, a frequency range/range of 5170 MHz to 5330 MHz in UNII-1 and UNII-2 may be divided into eight 20 MHz channels. The frequency range/range from 5170 MHz to 5330 MHz can be divided into four channels through the 40 MHz frequency domain. The 5170 MHz to 5330 MHz frequency domain/range can be divided into two channels through the 80 MHz frequency domain. Alternatively, the 5170 MHz to 5330 MHz frequency domain/range may be divided into one channel through the 160 MHz frequency domain.

17 shows an example of a channel used/supported/defined within a 6 GHz band.

The 6 GHz band may be referred to as a third band/band. The 6 GHz band may mean a frequency region in which channels with a center frequency of 5.9 GHz or more are used/supported/defined. The specific values shown in FIG. 17 may be changed.

For example, the 20 MHz channel of FIG. 17 may be defined from 5.940 GHz. Specifically, the leftmost channel of the 20 MHz channel of FIG. 17 may have an index number 1 (or a channel index, a channel number, etc.), and a center frequency of 5.945 GHz may be allocated. That is, the center frequency of the index N channel may be determined as (5.940 + 0.005*N) GHz.

Accordingly, the index (or channel number) of the 20 MHz channel of FIG. 17 is 1, 5, 9, 13, 17, 21, 25, 29, 33, 37, 41, 45, 49, 53, 57, 61, 65, 69, 73, 77, 81, 85, 89, 93, 97, 101, 105, 109, 113, 117, 121, 125, 129, 133, 137, 141, 145, 149, 153, 157, 161, It may be 165, 169, 173, 177, 181, 185, 189, 193, 197, 201, 205, 209, 213, 217, 221, 225, 229, 233. In addition, according to the above-described (5.940 + 0.005*N) GHz rule, the index of the 40 MHz channel in FIG. 17 is 3, 11, 19, 27, 35, 43, 51, 59, 67, 75, 83, 91, 99, 107, 115, 123, 131, 139, 147, 155, 163, 171, 179, 187, 195, 203, 211, 219, 227.

In the example of FIG. 17, 20, 40, 80, and 160 MHz channels are shown, but additionally, a 240 MHz channel or a 320 MHz channel may be added.

Hereinafter, the PPDU transmitted/received by the STA of the present specification will be described.

18 shows an example of a PPDU used in the present specification.

The PPDU of FIG. 18 may be referred to as various names such as EHT PPDU, transmission PPDU, reception PPDU, 1st type or Nth type PPDU. In addition, it can be used in the EHT system and/or a new wireless LAN system that has improved the EHT system.

The subfields of FIG. 18 may be changed to various names. For example, the SIG A field may be referred to as an EHT-SIG-A field, an SIG B field may be referred to as an EHT-SIG-B, an STF field may be referred to as an EHT-STF field, and an LTF field may be referred to as an EHT-LTF field.

The subcarrier spacing of the L-LTF, L-STF, L-SIG, and RL-SIG fields of FIG. 18 may be set to 312.5 kHz, and the subcarrier spacing of the STF, LTF, and Data fields may be set to 78.125 kHz. That is, the subcarrier index of the L-LTF, L-STF, L-SIG, and RL-SIG fields may be displayed in units of 312.5 kHz, and the subcarrier indexes of the STF, LTF, and Data fields may be displayed in units of 78.125 kHz.

The SIG A and/or SIG B fields of FIG. 18 may include additional fields (eg, SIG C or one control symbol, etc.). Of the SIG A and SIG B fields, all/some of the subcarrier spacing and all/some of the additionally defined SIG fields may be set to 312.5 kHz. Meanwhile, the subcarrier spacing for a part of the newly defined SIG field may be set to a preset value (eg, 312.5 kHz or 78.125 kHz).

In the PPDU of FIG. 18, the L-LTF and the L-STF may be the same as the conventional field.

The L-SIG field of FIG. 18 may include, for example, 24-bit bit information. For example, the 24-bit information may include a 4 bit Rate field, 1 bit Reserved bit, 12 bit Length field, 1 bit Parity bit, and 6 bit Tail bit. For example, the 12-bit Length field may include information on the number of octets of a Physical Service Data Unit (PSDU). For example, the value of the 12-bit Length field may be determined based on the type of PPDU. For example, when the PPDU is a non-HT, HT, VHT PPDU or EHT PPDU, the value of the Length field may be determined as a multiple of 3. For example, when the PPDU is an HE PPDU, the value of the Length field may be determined as “multiple of 3 + 1” or “multiple of 3 +2”. In other words, for non-HT, HT, VHT PPDU or EHT PPDU, the value of the Length field can be determined as a multiple of 3, and for HE PPDU, the value of the Length field is "multiple of 3 + 1" or "multiple of 3 It can be determined as +2”.

For example, the transmitting STA may apply BCC encoding based on a code rate of 1/2 to 24-bit information of the L-SIG field. Thereafter, the transmitting STA may obtain a 48-bit BCC coded bit. BPSK modulation is applied to the 48-bit coded bits, so that 48 BPSK symbols may be generated. The transmitting STA may map 48 BPSK symbols to locations excluding pilot subcarriers {subcarrier index -21, -7, +7, +21} and DC subcarrier {subcarrier index 0}. As a result, 48 BPSK symbols can be mapped to subcarrier indices -26 to -22, -20 to -8, -6 to -1, +1 to +6, +8 to +20, and +22 to +26. have. The transmitting STA may additionally map a signal of {-1, -1, -1, 1} to the subcarrier index {-28, -27, +27, +28}. The above signal can be used for channel estimation in the frequency domain corresponding to {-28, -27, +27, +28}.

The transmitting STA may generate the RL-SIG generated in the same manner as the L-SIG. BPSK modulation can be applied to RL-SIG. The receiving STA may know that the received PPDU is an HE PPDU or an EHT PPDU based on the presence of the RL-SIG.

After the RL-SIG of FIG. 18, for example, EHT-SIG-A or one control symbol may be inserted. Symbols located after RL-SIG (ie, EHT-SIG-A or one control symbol in the present specification) may be referred to as various names such as a U-SIG (Universal SIG) field.

A symbol (eg, U-SIG) consecutive to the RL-SIG may include information of N bits, and may include information for identifying the type of EHT PPDU. For example, the U-SIG may be configured based on two symbols (eg, two consecutive OFDM symbols). Each symbol (eg, OFDM symbol) for U-SIG may have a duration of 4 us. Each symbol of U-SIG can be used to transmit 26 bits of information. For example, each symbol of U-SIG may be transmitted and received based on 52 data tones and 4 pilot tones.

Through the U-SIG (or U-SIG field), for example, A-bit information (eg, 52 un-coded bits) may be transmitted, and the first symbol of U-SIG is the first of the total A-bit information. X-bit information (eg, 26 un-coded bits) is transmitted, and the second symbol of U-SIG can transmit remaining Y-bit information (eg, 26 un-coded bits) of the total A-bit information. have. For example, the transmitting STA may acquire 26 un-coded bits included in each U-SIG symbol. The transmitting STA may generate a 52-coded bit by performing convolutional encoding on the basis of a rate of R=1/2, and may perform interleaving on the 52-coded bit. The transmitting STA may generate 52 BPSK symbols allocated to each U-SIG symbol by performing BPSK modulation on the interleaved 52-coded bits. One U-SIG symbol may be transmitted based on 56 tones (subcarriers) from subcarrier index -28 to subcarrier index +28, excluding DC index 0. 52 BPSK symbols generated by the transmitting STA may be transmitted based on the remaining tones (subcarriers) excluding the pilot tones -21, -7, +7, and +21 tones.

For example, A-bit information (e.g., 52 un-coded bits) transmitted by U-SIG is a CRC field (e.g., a 4-bit long field) and a tail field (e.g., a 6-bit long field). ) Can be included. The CRC field and the tail field may be transmitted through the second symbol of U-SIG. The CRC field may be generated based on 26 bits allocated to the first symbol of U-SIG and the remaining 16 bits excluding the CRC/tail field in the second symbol, and may be generated based on a conventional CRC calculation algorithm. I can. In addition, the tail field may be used to terminate trellis of a convolutional decoder, and may be set to “000000”, for example.

A bit information (eg, 52 un-coded bits) transmitted by U-SIG (or U-SIG field) may be divided into version-independent bits and version-dependent bits. For example, the size of version-independent bits may be fixed or variable. For example, version-independent bits may be allocated only to the first symbol of U-SIG, or version-independent bits may be allocated to both the first symbol and the second symbol of U-SIG. For example, version-independent bits and version-dependent bits may be referred to by various names such as a first bit and a second bit.

For example, the version-independent bits of U-SIG may include a 3-bit PHY version identifier. For example, the 3-bit PHY version identifier may include information related to the PHY version of the transmission/reception PPDU. For example, the first value of the 3-bit PHY version identifier may indicate that the transmission/reception PPDU is an EHT PPDU. In other words, when transmitting the EHT PPDU, the transmitting STA may set a 3-bit PHY version identifier as the first value. In other words, the receiving STA may determine that the received PPDU is an EHT PPDU based on the PHY version identifier having the first value.

For example, the version-independent bits of U-SIG may include a 1-bit UL/DL flag field. The first value of the 1-bit UL/DL flag field is related to UL communication, and the second value of the UL/DL flag field is related to DL communication.

For example, the version-independent bits of U-SIG may include information on the length of TXOP and information on the BSS color ID.

For example, when the EHT PPDU is classified into various types (e.g., EHT PPDU supporting SU, EHT PPDU supporting MU, EHT PPDU related to Trigger Frame, EHT PPDU related to Extended Range transmission, etc.) , Information about the type of the EHT PPDU may be included in version-independent bits or version-dependent bits of U-SIG.

For example, the U-SIG field is 1) a bandwidth field containing information about the bandwidth, 2) a field containing information about the MCS technique applied to SIG-B, and 3) dual subcarrier modulation in SIG-B ( An indication field containing information related to whether or not dual subcarrier modulation) is applied, 4) A field containing information about the number of symbols used for SIG-B, 5) Whether SIG-B is generated over the entire band It may include a field including information on whether or not, 6) a field including information on an LTF/STF type, and 7) information on a field indicating the length of the LTF and the length of the CP.

The SIG-B of FIG. 18 may include the technical features of HE-SIG-B shown in the example of FIGS. 8 to 9 as it is.

The STF of FIG. 18 may be used to improve automatic gain control estimation in a multiple input multiple output (MIMO) environment or an OFDMA environment. The LTF of FIG. 18 may be used to estimate a channel in a MIMO environment or an OFDMA environment.

The STF of FIG. 18 may be set in various types. For example, the first type of STF (that is, 1x STF) may be generated based on a first type STF sequence in which non-zero coefficients are arranged at 16 subcarrier intervals. The STF signal generated based on the first type STF sequence may have a period of 0.8 μs, and the 0.8 μs period signal may be repeated 5 times to become a first type STF having a length of 4 μs. For example, the second type of STF (that is, 2x STF) may be generated based on a second type STF sequence in which non-zero coefficients are arranged at 8 subcarrier intervals. The STF signal generated based on the second type STF sequence may have a period of 1.6 μs, and the 1.6 μs period signal may be repeated 5 times to become a second type EHT-STF having a length of 8 μs. For example, a third type of STF (ie, 4x EHT-STF) may be generated based on a third type STF sequence in which non-zero coefficients are arranged at intervals of four subcarriers. The STF signal generated based on the third type STF sequence may have a period of 3.2 μs, and the period signal of 3.2 μs may be repeated 5 times to become a third type EHT-STF having a length of 16 μs. Only some of the above-described first to third type EHT-STF sequences may be used. In addition, the EHT-LTF field may have first, second, and third types (ie, 1x, 2x, 4x LTF). For example, the first/second/third type LTF field may be generated based on an LTF sequence in which non-zero coefficients are arranged at 4/2/1 subcarrier intervals. The first/second/third type LTF may have a time length of 3.2/6.4/12.8 μs. In addition, GIs of various lengths (eg, 0.8/1/6/3.2 μs) may be applied to the first/second/third type LTF.

Information on the type of STF and/or LTF (including information on GI applied to the LTF) may be included in the SIG A field and/or the SIG B field of FIG. 18.

The PPDU of FIG. 18 may support various bandwidths. For example, the PPDU of FIG. 18 may have a bandwidth of 20/40/80/160/240/320 MHz. For example, some fields (eg, STF, LTF, data) of FIG. 18 may be configured based on RUs shown in FIGS. 5 to 7, and the like. For example, when there is one receiving STA of the PPDU of FIG. 18, all fields of the PPDU of FIG. 18 may occupy the entire bandwidth. For example, when there are multiple receiving STAs of the PPDU of FIG. 18 (ie, when MU PPDU is used), some fields (eg, STF, LTF, data) of FIG. 18 are shown in FIGS. 5 to 7, etc. It can be configured based on the RU. For example, the STF, LTF, and data fields for the first receiving STA of the PPDU may be transmitted and received through the first RU, and the STF, LTF, and data fields for the second receiving STA of the PPDU are transmitted and received through the second RU. Can be. In this case, the positions of the first and second RUs may be determined based on FIGS. 5 to 7 and the like.

The PPDU of FIG. 18 may be determined (or identified) as an EHT PPDU based on the following method.

The receiving STA may determine the type of the received PPDU as the EHT PPDU based on the following items. For example, 1) the first symbol after the L-LTF signal of the received PPDU is BPSK, 2) RL-SIG where the L-SIG of the received PPDU is repeated is detected, and 3) the length of the L-SIG of the received PPDU When the result of applying “modulo 3” to the value is detected as “0”, the received PPDU may be determined as an EHT PPDU. When the received PPDU is determined to be an EHT PPDU, the receiving STA is the type of the EHT PPDU (e.g., SU/MU/Trigger-based/Extended Range type) based on bit information included in the symbol after RL-SIG of FIG. ) Can be detected. In other words, the receiving STA is 1) the first symbol after the L-LTF signal, which is BSPK, 2) RL-SIG that is consecutive to the L-SIG field and is the same as L-SIG, 3) the result of applying “modulo 3” L-SIG including a Length field set to 0”, and 4) a received PPDU based on a 3-bit PHY version identifier (eg, a PHY version identifier having a first value) of the aforementioned U-SIG. It can be judged as an EHT PPDU.

For example, the receiving STA may determine the type of the received PPDU as an HE PPDU based on the following. For example, 1) the first symbol after the L-LTF signal is BPSK, 2) RL-SIG repeating L-SIG is detected, and 3) “modulo 3” is applied to the length value of L-SIG. When the result is detected as “1” or “2”, the received PPDU may be determined as an HE PPDU.

For example, the receiving STA may determine the type of the received PPDU as non-HT, HT, and VHT PPDU based on the following items. For example, if 1) the first symbol after the L-LTF signal is BPSK, and 2) the L-SIG repeating RL-SIG is not detected, the received PPDU will be determined as non-HT, HT and VHT PPDU. I can. In addition, even if the receiving STA detects the repetition of RL-SIG, if the result of applying “modulo 3” to the length value of L-SIG is detected as “0”, the receiving PPDU is non-HT, HT and VHT PPDU. It can be judged as.

In the following example, (transmit/receive/uplink/downward) signal, (transmit/receive/uplink/downlink) frame, (transmit/receive/uplink/downlink) packet, (transmit/receive/uplink/downlink) data unit, ( A signal displayed as transmission/reception/up/down) data may be a signal transmitted/received based on the PPDU of FIG. 18. The PPDU of FIG. 18 may be used to transmit and receive various types of frames. For example, the PPDU of FIG. 18 may be used for a control frame. An example of a control frame may include request to send (RTS), clear to send (CTS), Power Save-Poll (PS-Poll), BlockACKReq, BlockAck, NDP (Null Data Packet) announcement, and Trigger Frame. For example, the PPDU of FIG. 18 may be used for a management frame. An example of a management frame may include a Beacon frame, (Re-)Association Request frame, (Re-)Association Response frame, Probe Request frame, and Probe Response frame. For example, the PPDU of FIG. 18 may be used for a data frame. For example, the PPDU of FIG. 18 may be used to simultaneously transmit at least two or more of a control frame, a management frame, and a data frame.

19 shows a modified example of the transmitting device and/or the receiving device of the present specification.

Each of the devices/STAs of sub-drawings (a)/(b) of FIG. 1 may be modified as shown in FIG. 19. The transceiver 630 of FIG. 19 may be the same as the transceivers 113 and 123 of FIG. 1. The transceiver 630 of FIG. 19 may include a receiver and a transmitter.

The processor 610 of FIG. 19 may be the same as the processors 111 and 121 of FIG. 1. Alternatively, the processor 610 of FIG. 19 may be the same as the processing chips 114 and 124 of FIG. 1.

The memory 150 of FIG. 19 may be the same as the memories 112 and 122 of FIG. 1. Alternatively, the memory 150 of FIG. 19 may be a separate external memory different from the memories 112 and 122 of FIG. 1.

Referring to FIG. 19, the power management module 611 manages power for the processor 610 and/or the transceiver 630. The battery 612 supplies power to the power management module 611. The display 613 outputs a result processed by the processor 610. Keypad 614 receives input to be used by processor 610. The keypad 614 may be displayed on the display 613. The SIM card 615 may be an integrated circuit used to securely store an IMSI (international mobile subscriber identity) used to identify and authenticate a subscriber in a mobile phone device such as a mobile phone and a computer and a key associated therewith. .

Referring to FIG. 19, the speaker 640 may output a sound-related result processed by the processor 610. The microphone 641 may receive a sound-related input to be used by the processor 610.

20 shows examples of various types of PPDUs.

As shown in FIG. 20, examples of the type (ie, format) of the PPDU used in the WLAN system include non-HT, HT, VHT, HE PPDU, and the like. Specifically, the illustrated first type PPDU 2010 is a non-HT PPDU defined in the IEEE 802.11a standard, etc., and the illustrated second type PPDU 2020 and the third type PPDU 2030 are defined in the IEEE 802.11n standard, etc. It is the HT PPDU. In addition, the illustrated fourth type PPDU 2040 is a VHT PPDU defined in the IEEE 802.11ac standard, and the illustrated fifth type PPDU 2050 and the sixth type PPDU 2060 are HE PPDUs defined in IEEE 802.11ax standards, etc. to be.

All types of PPDUs 2010, 2020, 2030, 2040, 2050, and 2060 shown in FIG. 20 include L-STF and L-LTF fields. Each of the L-STF and L-LTF fields may be transmitted through two symbols (eg, OFDM symbols). That is, each of the L-STF and L-LTF fields may have a transmission time of 8 us.

All types of PPDUs 2010, 2020, 2030, 2040, 2050, and 2060 shown in FIG. 20 include an L-SIG field or an HT-SIG1 field consecutive to the L-LTF field. The L-SIG field or the HT-SIG1 field shown in FIG. 20 may be transmitted through one symbol.

As shown in FIG. 20, the HT-SIG1 field of the third type PPDU 2030 may be modulated based on a quadrature binary phase shift keying (QBPSK) property. The QBPSK constellation may be a constellation rotated by 90 degrees counterclockwise based on the BPSK constellation.

21 is a diagram for distinguishing between BPSK and QBPSK. As shown, the QBPSK constellation may be a constellation rotated by 90 degrees counterclockwise based on the BPSK constellation.

Since QBPSK is applied to the HT-SIG1 field of the third type PPDU 2030 of FIG. 20, the receiving STA can identify that the received PPDU is a third type PPDU when QBPSK is applied to a symbol received after the L-LTF field. have. In addition, when BPSK is applied to a symbol received after the L-LTF field, the receiving STA may identify that the received PPDU is any one of the first, second, fourth, fifth, and sixth type PPDUs.

PPDUs of the fifth and sixth types may be identified/detected by the receiving STA based on the following example. In the fifth and sixth types of PPDUs, a field consecutive to the L-SIG field is a Repeated L-SIG (RL-SIG) in which L-SIG is repeated as it is. In addition, in the fifth and sixth type PPDUs, three SIG fields exist after the L-SIG field. The receiving STA identifies that the received PPDU is a 5th and 6th type PPDU when the L-SIG is repeated as it is in a symbol consecutive to the L-SIG field, and there are three SIG fields after the L-SIG field. Can be detected.

Meanwhile, in the fifth type of PPDU 2050, the property applied to the third SIG field after the L-SIG field is BPSK, and the sixth type of PPDU 2060 is applied to the third SIG field after the L-SIG field. QBPSK is the characteristic that becomes. Accordingly, the receiving STA may distinguish between the fifth and sixth types of PPDUs based on whether the constellation applied to the third SIG field after the L-SIG field is BPSK or QPBSK.

In addition, in the fourth type of PPDU, the L-SIG is not repeated as it is in the L-SIG field, and BPSK is applied to the first symbol consecutive to the L-SIG, and the second QBPSK is applied to the symbol. Accordingly, the receiving STA may identify the PPDU of the fourth type based on (whether the L-SIG field is repeated and/or) whether QBPSK is applied to the second symbol.

In addition, since QBPSK is applied to two symbols consecutive to the L-SIG in the second type of PPDU, the receiving STA can identify/detect the second type of PPDU from another type of PPDU. In addition, as described above, since all PPDUs of the 2nd to 6th type have distinguishable characteristics, if a PPDU that is not identified/detected as a PPDU of the 2nd to 6th type can be identified/detected as a PPDU of the first type. have.

The specific order of the above-described identification/detection method may be changed. That is, when the number/constellation of symbols after the L-LTF is uniquely configured as shown in FIG. 20, the receiving STA can accurately identify the type of the received PPDU through various methods.

22 shows a band plan of 5.9GHz DSRC.

The 5.9 GHz DSRC is a short to medium distance communication service that supports both public safety and private work in vehicles and vehicle-to-vehicle communication environments on the road. DSRC is intended to complement cellular communication by providing a very high data transmission rate in a situation where it is important to minimize the latency of a communication link and separate a relatively small communication area. In addition, the PHY and MAC protocols are based on the IEEE 802.11p amendment for wireless access in the vehicle environment (WAVE).

<IEEE 802.11p>

802.11p uses the 802.11a PHY by 2x down clocking. That is, the signal is transmitted using 10MHz bandwidth, not 20MHz bandwidth. The numerology comparing 802.11a and 802.11p is as follows.

There are a control channel and a service channel in the DSRC band channel, and 3,4.5,6,9,12,18,24,27 Mbps of data transmission is possible, respectively. If there is an option channel of 20MHz, transmission of 6,9,12,18,24,36,48,54 Mbps is possible. 6,9,12 Mbps must be supported in all services and channels. In the case of the control channel, the preamble is 3 Mbps, but the message itself is 6 Mbps. Channels 174 and 176, and channels 180 and 182 are channels 175 and 181 at 20 MHz, respectively, if licensed by the frequency coordinating authority. The rest is reserved for future use. It broadcasts short messages, notification data, public safety alarm data, etc. to all OBUs (On Board Units) through the control channel. The reason for separating the control channel and the service channel is to maximize efficiency and service quality and reduce interference between services.

Channel 178 is a control channel, and all OBUs automatically search for the control channel and receive notification, data transmission, and warning messages from RSU (Road Side Unit). All data on the control channel must be transmitted within 200ms and is repeated at a predefined period. In the control channel, public safety alerts take precedence over all private messages. Private messages larger than 200ms are transmitted over the service channel.

Private messages or long public safety messages are transmitted through the service channel. To prevent collision, a technique that detects the channel state before transmission (Carrier Sense Multiple Access: CSMA) is used.

23 shows a frame format of a frame according to the 802.11p standard.

Referring to FIG. 23, a frame (or packet) according to the 802.11p standard (hereinafter, an 11p frame 2300 may support vehicle-to-vehicle communication in a 5.9 GHz band. The 11p frame 2300 is synchronized (or sync) and AGC) A signal field (or SIG field) 2330 including information on the STF 2310 for (Automatic Gain Control), the LTF 2320 for channel estimation, and/or the Data field 2340 may be included. The data field 2340 may be configured to include 16 bits constituting a service field.

The 11p frame 2300 may be configured by applying OFMDM numerology identical to the 802.11a standard for a 10 MHz bandwidth. For example, the 802.11p standard can be applied by 2x down clocking the OFDM numerology for a 20MHz bandwidth according to the 802.11a standard. Accordingly, the symbol of the 11p frame 2300 may be set longer than the symbol of the frame according to the 802.11a standard. The symbol of the 11p frame 2300 may have a symbol duration of 8 us. The 11p frame 2300 may have a length twice as long in terms of time than the frame according to the 802.11a standard.

24 shows an embodiment of a PPDU format.

Referring to FIG. 24, the PPDU 2400 may be configured in a 10 MHz bandwidth. For example, the PPDU 2400 may be a frame conforming to the IEEE802.11bd standard. For backward compatibility and/or interoperability with the IEEE802.11p standard, the PPDU 2400 may include a preamble part of the IEEE802.11p frame. For example, the PPDU 2400 may include an L-STF 2410, an L-LTF 2420, or an L-SIG (or L-SIG field) 2430. Additionally, NGV-SIG (or NGV-SIG field) 2440, NGV-STF 2450, NGV-LTF 2460, and NGV Data (or NGV-Data field) including control information for NGV (2470) may be configured in succession to the L-SIG (2430).

The NGV-SIG 2440 may be related to transmission information. For example, the NGV-SIG 2440 may include transmission information. For example, the NGV-SIG 2440 may include information on bandwidth, MCS, Nss, Midamble periodicity, LDPC Extra symbol, LTF format, or tail bit. BCC encoding based on a coding rate of 1/2 may be applied to the NGV-SIG 2440.

The NGV-STF 2450 can be configured by downclocking a 20MHz VHT-STF according to the IEEE802.11ac standard by 2x. The NGV-LTF 2460 can be configured by downclocking a 20MHz VHT-LTF according to the IEEE802.11ac standard by 2x.

25 and 26 are diagrams illustrating an embodiment of a PPDU format.

25 and 26, PPDUs 2500 and 2600 may include L-STF, L-LTF, L-SIG, 11bd-LTF, and NGV-data fields. For example, the PPDUs 2500 and 2600 may be 11bd frames supporting IEEE802.11bd.

The PPDU 2500 of FIG. 25 may be configured for a 10 MHz bandwidth. The PPDU 2600 of FIG. 26 may be configured for a 20 MHz bandwidth. The PPDU (2500, 2600) may be configured to operate in the 5.9 GHz Intelligent Transportation Systems (ITS) band to be interoperable with the IEEE802.11p standard.

A device supporting the IEEE802.11bd standard (hereinafter, referred to as an 11bd device) whether there is a device supporting the IEEE802.11p standard (hereinafter referred to as an 11p device) through preamble detection, probe request/response or transmission/reception of CTS/RTS signals. You can check. The 11bd device may transmit an 11bd frame (or 11bd PPDU) when there is no 11p device nearby. In other words, the 11bd device may transmit an 11bd frame (or 11bd PPDU) based on the presence or absence of an 11p device around the 11bd device. The 11bd device may transmit PPDUs 2500 and 2600 shown in FIGS. 25 and/or 26 in order to reduce an influence on a hidden node.

For example, the PPDU (2500, 2600) can support only a single stream (single stream). Therefore, the NGV-STF field may not be used. For example, IEEE802.11bd does not include a signal field (e.g., NGV SIG or signal field) indicating transmission information because information on transmission and reception can be received through an upper layer. May not. Therefore, 11bd-LTF (or NGV-LTF) may be located immediately after the L-SIG field. That is, 11bd-LTF (or NGV-LTF) may continue to L-SIG. NGV-data may be consecutive to 11bd-LTF (or NGV-LTF).

NGV-LTF may be set in at least one LTF format. For example, NGV-LTF may be set to one of NGV-LTF-1x format, NGV-LTF-2x format, or repeated NGV-LTF-2x format. Information on the LTF format used in NGV-LTF may be included in the NGV-SIG.

For example, the NGV-LTF-2x format may be set as a default format. As another example, the NGV-LTF-1x format may be used for highly efficient transmission of one spatial stream. As another example, the repeated NGV-LTF-2x format may be used for extended range transmissions. The repeated NGV-LTF-2x format can be configured by repeating a 1.6 us pre-append NGV-LTF-2x format symbol excluding one CP (cyclic prefix) and GI (guad interval). have. The repeated NGV-LTF-2x format can be used when DCM (dual carrier modulation) and BPSK modulation are applied to NGV data. For example, when DCM (dual carrier modulation) and BPSK modulation are applied to NGV data, the repeated NGV-LTF-2x format is applied to NGV-LTF regardless of the information on the LTF format included in NGV-SIG. Can be used/applied.

For example, in 10 MHz transmission, a sequence in the form of NGV-LTF-1x may be set as shown in Equation 1.

For example, in 10 MHz transmission, a sequence in the form of NGV-LTF-2x may be set as shown in Equation 2.

In Equation 2, LTF_left and LTF_right may be set as in Equation 3.

NGV data may include a service field, PHY pad bits, and/or PSDU.

27 is a diagram showing an embodiment of a PPDU format.

Referring to FIG. 27, packet classification may be performed based on an 11bd-LTF (or NGV LTF) field. That is, the receiving STA is based on the 11bd-LTF (or NGV LTF) field of the receiving PPDU 2700, the type of the PPDU 2700 (that is, the wireless LAN system supported by the PPDU 2700 (eg, IEEE802. 11bd) can be seen.

For example, the PPDU 2700 may support only a single stream. Therefore, the NGV-STF field may not be used. For example, IEEE802.11bd does not include a signal field (e.g., NGV SIG or signal field) indicating transmission information because information on transmission and reception can be received through an upper layer. May not. Therefore, 11bd-LTF (or NGV-LTF) may be located immediately after the L-SIG field. That is, 11bd-LTF (or NGV-LTF) may continue to L-SIG. NGV-data may be consecutive to 11bd-LTF (or NGV-LTF).

For 11bd-LTF, quadrature-binary phase shift keying (Q-BPSK) constellation mapping may be applied. 11bd-LTF may consist of one symbol. The receiving STA (eg, 11bd device) provides information on the constellation of the LTF symbol (eg, 11bd-LTF or NGV LTF) in the L-SIG field included in the received PPDU 2700. Can be obtained. The receiving STA may determine that the received PPDU 2700 is an 11bd signal when the property of the LTF symbol consecutive to the L-SIG field included in the received PPDU 2700 is Q-BPSK. That is, the receiving STA may determine that the type of the received PPDU 2700 is 11bd PPDU when the property of the LTF symbol consecutive to the L-SIG field included in the received PPDU 2700 is Q-BPSK. The receiving STA may determine that the received PPDU 2700 is a PPDU 2700 supporting IEEE802.11bd when the property of the LTF symbol consecutive to the L-SIG field included in the received PPDU 2700 is Q-BPSK. have.

Since the Euclidean distance between BPSK and Q-BPSK is large, there is an effect of reducing false detection. That is, there is an effect of increasing the success rate of demodulation. In addition, since packet classification can be performed using only one training symbol consecutive to the L-SIG symbol, packet classification (for example, detection) is faster than that of a conventional wireless local area network (WLAN). ) Has the effect of being able to perform.

In IEEE802.11p, constellation mapping for a symbol next to L-SIG may be the same as that of BPSK of FIG. 21, and in IEEE802.11bd, constellation mapping for a symbol following L-SIG may be the same as that of Q-BPSK of FIG. That is, in IEEE802.11p, symbols consecutive to L-SIG (for example, OFDM symbols) can be modulated with BPSK, and in IEEE802.11bd, symbols continuing to L-SIG are Q-BPSK. Can be modulated with

By applying 11bd Q-BPSK modulation as described above, 11bd can quickly determine whether the received PPDU is 11p or 11bd by using whether the LTF is rotated when receiving a signal. That is, when the receiving STA receives the PPDU, when a symbol following the L-SIG (ie, a symbol consecutive to the L-SIG) is an 11bd LTF symbol with Q-BPSK modulation, the received PPDU may determine that the received PPDU is 11bd. Therefore, the receiving STA has an effect of being able to quickly determine whether the received PPDU is an 11bd PPDU.

In addition, since a separate symbol for packet classification may not be added, there is an effect of reducing PPDU overhead.

Constellation rotation (ie, Q-BPSK) applied to the LTF (ie, 11bd-LTF or NGV LTF) is only one embodiment, and QPSK may be applied to the LTF.

28 is a flowchart illustrating an embodiment of an operation of a receiving STA (station).

Referring to FIG. 28, a receiving STA may receive a PPDU (S2810). For example, the PPDU is a first legacy training field (eg, L-STF), a second legacy training field (eg, L-LTF), a legacy control field (eg, L-SIG ), and a next generation vehicular network (NGV) training field (eg, NGV-LTF or 11bd-LTF). For example, the PPDU may be configured based on FIG. 27.

For example, the PPDU can support only a single stream. Therefore, the NGV-STF field may not be used. For example, IEEE802.11bd does not include a signal field (e.g., NGV SIG or signal field) indicating transmission information because information on transmission and reception can be received through an upper layer. May not. Accordingly, an NGV training field (eg, 11bd-LTF or NGV-LTF) may be positioned immediately after the legacy control field (eg, L-SIG). That is, the NGV training field (eg, 11bd-LTF or NGV-LTF) may be contiguous to the legacy control field (eg, L-SIG). The data field (eg, NGV-data) may be contiguous to the NGV training field (eg, 11bd-LTF or NGV-LTF).

The receiving STA may receive the legacy control field through the first symbol, and the NGV training field may receive the second symbol consecutive to the first symbol. The first symbol may be modulated based on a first constellation, and the second symbol may be modulated based on a second constellation rotated based on the first constellation.

For example, the PPDU can support only a single stream. Therefore, the NGV-STF field may not be used. For example, IEEE802.11bd does not include a signal field (e.g., NGV SIG or signal field) indicating transmission information because information on transmission and reception can be received through an upper layer. May not. Therefore, an NGV training field (eg, 11bd-LTF or NGV-LTF) may be positioned immediately after the L-SIG field. That is, the NGV training field (eg, 11bd-LTF or NGV-LTF) may be contiguous to the legacy control field (eg, L-SIG). The data field (eg, NGV-data) may be contiguous to the NGV training field (eg, 11bd-LTF or NGV-LTF).

Quadrature-binary phase shift keying (Q-BPSK) constellation mapping may be applied to the NGV training field (eg, 11bd-LTF or NGV-LTF). For example, the NGV training field may consist of one symbol. The receiving STA (e.g., 11bd device) is the constellation of a symbol (e.g., a second symbol) consecutive to the legacy control field (or symbol related to the legacy control field) included in the received PPDU. Information can be obtained. The receiving STA may determine that the received PPDU is an 11bd signal when the property of a symbol consecutive to the legacy control field included in the received PPDU is Q-BPSK. For example, the receiving STA is that the constellation of a symbol related to a legacy control field (eg, L-SIG field) included in the received PPDU is modulated based on BPSK, and a symbol consecutive to the symbol related to the legacy control field When the property of is modulated based on Q-BPSK, it may be determined that the type of the received PPDU is 11bd PPDU. The receiving STA may determine that the received PPDU is a PPDU supporting IEEE802.11bd when the property of a symbol consecutive to the L-SIG field included in the received PPDU is Q-BPSK. That is, the receiving STA may acquire information on the type of PPDU based on the first constellation and the second constellation (S2830).

Since the Euclidean distance between BPSK and Q-BPSK is large, there is an effect of reducing false detection. That is, there is an effect of increasing the success rate of demodulation. In addition, since packet classification can be performed using only one training symbol consecutive to the L-SIG symbol, packet classification (for example, detection) is faster than that of a conventional wireless local area network (WLAN). ) Has the effect of being able to perform.

In IEEE802.11p, constellation mapping for a symbol next to L-SIG may be the same as that of BPSK of FIG. 21, and in IEEE802.11bd, constellation mapping for a symbol following L-SIG may be the same as that of Q-BPSK of FIG. That is, in IEEE802.11p, symbols consecutive to L-SIG (for example, OFDM symbols) can be modulated with BPSK, and in IEEE802.11bd, symbols continuing to L-SIG are Q-BPSK. Can be modulated with

By applying 11bd Q-BPSK modulation as described above, 11bd can quickly determine whether the received PPDU is 11p or 11bd by using whether the LTF is rotated when receiving a signal. That is, when the receiving STA receives the PPDU, when a symbol following the L-SIG (ie, a symbol consecutive to the L-SIG) is an 11bd LTF symbol with Q-BPSK modulation, the received PPDU may determine that the received PPDU is 11bd. Therefore, the receiving STA has an effect of being able to quickly determine whether the received PPDU is an 11bd PPDU.

In addition, since a separate symbol for packet classification may not be added, there is an effect of reducing PPDU overhead.

Constellation rotation (ie, Q-BPSK) applied to the LTF (ie, 11bd-LTF or NGV LTF) is only one embodiment, and QPSK may be applied to the LTF.

The NGV training field can be used for channel estimation. The PPDU further includes a data field, and the data field may be consecutive to the NGV training field. The first constellation may be modulated based on binary phase shift keying (BPSK), and the second constellation may be modulated based on quadrature BPSK (Q-BPSK). The second constellation may be rotated 90 degrees counterclockwise based on the first constellation.

The receiving STA may decode the received PPDU based on the PPDU type information acquired in S2820 (S2830).

29 is a flowchart illustrating an embodiment of a transmitting STA (station) operation.

Referring to FIG. 29, the transmitting STA may generate a PPDU (S2910). The transmitting STA may generate a PPDU preamble. The transmitting STA is a legacy part (ie, a first legacy training field (eg, L-STF), a second legacy training field (eg, L-LTF), a legacy control field (eg, L-SIG)) ) Can be created. The transmitting STA may generate an NGV training field (eg, 11bd-LTF or NGV LTF) and may modulate by applying Q-BPSK to the NGV training field.

For example, the PPDU can support only a single stream. Therefore, the NGV-STF field may not be used. For example, IEEE802.11bd does not include a signal field (e.g., NGV SIG or signal field) indicating transmission information because information on transmission and reception can be received through an upper layer. May not. Accordingly, an NGV training field (eg, 11bd-LTF or NGV-LTF) may be positioned immediately after the legacy control field (eg, L-SIG). That is, the NGV training field (eg, 11bd-LTF or NGV-LTF) may be contiguous to the legacy control field (eg, L-SIG). The data field (eg, NGV-data) may be contiguous to the NGV training field (eg, 11bd-LTF or NGV-LTF).

Quadrature-binary phase shift keying (Q-BPSK) constellation mapping may be applied to the NGV training field (eg, 11bd-LTF or NGV-LTF). For example, the NGV training field may consist of one symbol.

The transmitting STA may transmit a PPDU (S2920).

Some of the detailed steps shown in the examples of FIGS. 28 and 29 may be omitted, and other steps may be added. For example, in FIG. 28, the step of decoding the PPDU by the receiving STA (S2830) may be omitted.

The technical features of the present specification described above can be applied to various devices and methods. For example, the technical features of the present specification described above may be performed/supported through the apparatus of FIGS. 1 and/or 19. For example, the technical features of the present specification described above may be applied only to a part of FIGS. 1 and/or 19. For example, the technical features of the present specification described above may be implemented based on the processing chips 114 and 124 of FIG. 1, or implemented based on the processors 111 and 121 and the memories 112 and 122 of FIG. 1. , May be implemented based on the processor 610 and the memory 620 of FIG. 19. For example, the apparatus of the present specification includes a memory and a processor operably coupled to the memory, wherein the processor includes a first legacy training field, a second legacy training field, a legacy control field, And a PPDU (physical protocol data unit) including a next generation vehicular network (NGV) training field, wherein the legacy control field is received through a first symbol, and the NGV training field is a first symbol consecutive to the first symbol. It is received through 2 symbols, the first symbol is modulated based on a first constellation, the second symbol is modulated based on a second constellation rotated based on the first constellation, and It may be set to obtain information on the type of the PPDU based on the first constellation and the second constellation.

Technical features of the present specification may be implemented based on a computer readable medium (CRM). For example, the CRM proposed by the present specification is an instruction based on being executed by at least one processor of a shared AP (Access Point) of a wireless local area network (LAN) system ( instruction), comprising: a first legacy training field, a second legacy training field, a legacy control field, and a next generation vehicular network (NGV) in at least one computer readable medium including: Receives a PPDU (physical protocol data unit) including a training field, wherein the legacy control field is received through a first symbol, and the NGV training field is received through a second symbol consecutive to the first symbol, and the The first symbol is modulated based on a first constellation, and the second symbol is modulated based on a second constellation rotated based on the first constellation, and the first constellation and the second constellation It is possible to store instructions for performing an operation including acquiring information on the type of the PPDU based on. Instructions stored in the CRM of the present specification may be executed by at least one processor. At least one processor related to the CRM of the present specification may be the processors 111 and 121 or the processing chips 114 and 124 of FIG. 1, or the processor 610 of FIG. 19. Meanwhile, the CRM of the present specification may be the memories 112 and 122 of FIG. 1, the memory 620 of FIG. 19, or a separate external memory/storage medium/disk.

The technical features of the present specification described above can be applied to various applications or business models. For example, the UE, Terminal, STA, Transmitter, Receiver, Processor, and/or Transceiver described in the present specification may be applied to a vehicle supporting autonomous driving or a conventional vehicle supporting autonomous driving.

30 illustrates a vehicle or an autonomous vehicle applied to the present specification. The vehicle or autonomous vehicle may be implemented as a mobile robot, a vehicle, a train, an aerial vehicle (AV), or a ship.

The memory unit 3030 shown in FIG. 30 may be included in the memories 112 and 122 shown in FIG. 1. In addition, the communication unit 3010 illustrated in FIG. 30 may be included in the transceivers 113 and 123 and/or the processors 111 and 121 disclosed in FIG. 1. In addition, the remaining devices illustrated in FIG. 30 may be included in the processors 111 and 121 disclosed in FIG. 1.

Referring to FIG. 30, the vehicle or autonomous vehicle 3000 includes an antenna unit 3008, a communication unit 3010, a control unit 3020, a memory unit 3030, a driving unit 3040a, a power supply unit 3040b, and a sensor unit. (3040c) and/or an autonomous driving unit 3040d. The antenna unit 3008 may be configured as a part of the communication unit 3010.

The communication unit 3010 may transmit and receive signals (eg, data, control signals, etc.) with external devices such as other vehicles, base stations (e.g. base stations, roadside base stations, etc.), and servers. The controller 3020 may perform various operations by controlling elements of the vehicle or the autonomous vehicle 3000. The control unit 3020 may include an Electronic Control Unit (ECU). The driving unit 3040a may cause the vehicle or the autonomous vehicle 3000 to travel on the ground. The driving unit 3040a may include an engine, a motor, a power train, a wheel, a brake, a steering device, and the like. The power supply unit 3040b supplies power to the vehicle or the autonomous vehicle 3000, and may include a wired/wireless charging circuit, a battery, and the like. The sensor unit 3040c may obtain vehicle status, surrounding environment information, user information, and the like. The sensor unit 3040c is an IMU (inertial measurement unit) sensor, a collision sensor, a wheel sensor, a speed sensor, a tilt sensor, a weight detection sensor, a heading sensor, a position module, and a vehicle advancement. /Reverse sensor, battery sensor, fuel sensor, tire sensor, steering sensor, temperature sensor, humidity sensor, ultrasonic sensor, illumination sensor, pedal position sensor, etc. may be included. The autonomous driving unit 3040d is a technology that maintains a driving lane, a technology that automatically adjusts the speed such as adaptive cruise control, a technology that automatically travels along a predetermined route, and automatically sets a route when a destination is set. Technology, etc. can be implemented.

For example, the communication unit 3010 may receive map data and traffic information data from an external server. The autonomous driving unit 3040d may generate an autonomous driving route and a driving plan based on the acquired data. The control unit 3020 may control the driving unit 3040a so that the vehicle or the autonomous vehicle 3000 moves along the autonomous driving path according to the driving plan (eg, speed/direction adjustment). During autonomous driving, the communication unit 3010 asynchronously/periodically acquires the latest traffic information data from an external server, and may acquire surrounding traffic information data from surrounding vehicles. Also, during autonomous driving, the sensor unit 3040c may acquire vehicle status and surrounding environment information. The autonomous driving unit 3040d may update the autonomous driving route and the driving plan based on newly acquired data/information. The communication unit 3010 may transmit information about a vehicle location, an autonomous driving route, and a driving plan to an external server. The external server may predict traffic information data in advance using AI technology or the like based on information collected from the vehicle or autonomously driving vehicles, and may provide the predicted traffic information data to the vehicle or autonomously driving vehicles.

An example of this specification includes the example of FIG. 31 described below.

31 shows an example of a vehicle based on the present specification. Vehicles may also be implemented as means of transport, trains, aircraft, and ships.

Referring to FIG. 31, the vehicle 3000 may include a communication unit 3010, a control unit 3020, a memory unit 3030, an input/output unit 3040e, and a position measurement unit 3040f. Each block/unit/device shown in FIG. 31 may be the same as the block/unit/device shown in FIG. 30.

The communication unit 3010 may transmit and receive signals (eg, data, control signals, etc.) with other vehicles or external devices such as a base station. The controller 3020 may perform various operations by controlling components of the vehicle 3000. The memory unit 3030 may store data/parameters/programs/codes/commands supporting various functions of the vehicle 3000. The input/output unit 3040e may output an AR/VR object based on information in the memory unit 3030. The input/output unit 3040e may include a HUD. The location measurement unit 3040f may obtain location information of the vehicle 3000. The location information may include absolute location information of the vehicle 3000, location information within a driving line, acceleration information, location information with respect to surrounding vehicles, and the like. The location measurement unit 3040f may include GPS and various sensors.

For example, the communication unit 3010 of the vehicle 3000 may receive map information, traffic information, etc. from an external server and store it in the memory unit 3030. The location measurement unit 3040f may acquire vehicle location information through GPS and various sensors and store the vehicle location information in the memory unit 3030. The controller 3020 may generate a virtual object based on map information, traffic information, vehicle location information, and the like, and the input/output unit 3040e may display the generated virtual object on a window of the vehicle (3110, 3120). In addition, the controller 3020 may determine whether the vehicle 3000 is operating normally within a driving line based on the vehicle location information. When the vehicle 3000 deviates from the driving line abnormally, the control unit 3020 may display a warning on the window of the vehicle through the input/output unit 3040e. In addition, the controller 3020 may broadcast a warning message regarding a driving abnormality to nearby vehicles through the communication unit 3010. Depending on the situation, the controller 3020 may transmit location information of the vehicle and information on driving/vehicle abnormalities to a related organization through the communication unit 3010.

The technical features of the present specification described above can be applied to another application or business model.

For example, for wireless communication in a device supporting artificial intelligence (AI), the above-described technical features may be applied.

Artificial intelligence refers to the field of researching artificial intelligence or the methodology to create it, and machine learning (Machine Learning) refers to the field of researching methodologies to define and solve various problems dealt with in the field of artificial intelligence. do. Machine learning is also defined as an algorithm that improves the performance of a task through continuous experience.

An artificial neural network (ANN) is a model used in machine learning, and may refer to an overall model with problem-solving capability, which is composed of artificial neurons (nodes) that form a network by combining synapses. The artificial neural network may be defined by a connection pattern between neurons of different layers, a learning process for updating model parameters, and an activation function for generating an output value.

The artificial neural network may include an input layer, an output layer, and optionally one or more hidden layers. Each layer includes one or more neurons, and the artificial neural network may include neurons and synapses connecting neurons. In an artificial neural network, each neuron can output a function of an activation function for input signals, weights, and biases input through synapses.

Model parameters refer to parameters determined through learning, and include weights of synaptic connections and biases of neurons. In addition, hyperparameters refer to parameters that must be set before learning in a machine learning algorithm, and include a learning rate, iteration count, mini-batch size, and initialization function.

The purpose of learning artificial neural networks can be seen as determining model parameters that minimize the loss function. The loss function can be used as an index to determine an optimal model parameter in the learning process of the artificial neural network.

Machine learning can be classified into supervised learning, unsupervised learning, and reinforcement learning according to the learning method.

Supervised learning refers to a method of training an artificial neural network when a label for training data is given, and a label indicates the correct answer (or result value) that the artificial neural network should infer when training data is input to the artificial neural network. It can mean. Unsupervised learning may refer to a method of training an artificial neural network in a state where a label for training data is not given. Reinforcement learning may mean a learning method in which an agent defined in a certain environment learns to select an action or action sequence that maximizes the cumulative reward in each state.

Among artificial neural networks, machine learning implemented as a deep neural network (DNN) including a plurality of hidden layers is sometimes referred to as deep learning (deep learning), and deep learning is a part of machine learning. Hereinafter, machine learning is used in the sense including deep learning.

In addition, the above-described technical features can be applied to wireless communication of a robot.

A robot may refer to a machine that automatically processes or operates a task given by its own capabilities. In particular, a robot having a function of recognizing the environment and performing an operation by self-determining may be referred to as an intelligent robot.

Robots can be classified into industrial, medical, household, military, etc. depending on the purpose or field of use. The robot may be provided with a driving unit including an actuator or a motor to perform various physical operations such as moving a robot joint. In addition, the movable robot includes a wheel, a brake, a propeller, etc. in a driving unit, and can travel on the ground or fly in the air through the driving unit.

In addition, the above-described technical features may be applied to a device supporting extended reality.

The extended reality collectively refers to Virtual Reality (VR), Augmented Reality (AR), and Mixed Reality (MR). VR technology provides only CG images of real world objects or backgrounds, AR technology provides virtually created CG images on top of real object images, and MR technology is a computer that mixes and combines virtual objects in the real world. It is a graphic technology.

MR technology is similar to AR technology in that it shows real and virtual objects together. However, in AR technology, virtual objects are used in a form that complements real objects, whereas in MR technology, virtual objects and real objects are used with equal characteristics.

XR technology can be applied to HMD (Head-Mount Display), HUD (Head-Up Display), mobile phones, tablet PCs, laptops, desktops, TVs, digital signage, etc., and devices applied with XR technology are XR devices. It can be called as.

The claims set forth herein may be combined in a variety of ways. For example, the technical features of the method claims of the present specification may be combined to be implemented as a device, and the technical features of the device claims of the present specification may be combined to be implemented by a method. In addition, the technical characteristics of the method claim of the present specification and the technical characteristics of the device claim may be combined to be implemented as a device, and the technical characteristics of the method claim of the present specification and the technical characteristics of the device claim may be combined to be implemented by a method.

Claims (14)

1. In a method performed in a wireless local area network (LAN) system,

   STA (station) receives a PPDU (physical protocol data unit) including a first legacy training field, a second legacy training field, a legacy control field, and a next generation vehicular network (NGV) training field,

   The legacy control field is received through a first symbol, the NGV training field is received through a second symbol successive to the first symbol,

   Wherein the first symbol is modulated based on a first constellation, and the second symbol is modulated based on a second constellation rotated based on the first constellation; And

   Comprising, by the STA, obtaining information on the type of the PPDU based on the first constellation and the second constellation,

   Way.
2. The method according to claim 1,

   The NGV training field is used for channel estimation,

   Way.
3. The method according to claim 1,

   The PPDU further includes a data field,

   The data field is continuous to the NGV training field,

   Way.
4. The method according to claim 1,

   The first constellation is modulated based on binary phase shift keying (BPSK),

   The second constellation is modulated based on Q-BPSK (quadrature BPSK),

   Way.
5. The method according to claim 1,

   The second constellation is rotated 90 degrees counterclockwise based on the first constellation,

   Way.
6. In the STA (station) used in a wireless local area network (LAN) system, the STA,

   A transceiver for transmitting and receiving a radio signal; And

   Including a processor connected to the transceiver, wherein the processor,

   Receiving a PPDU (physical protocol data unit) including a first legacy training field, a second legacy training field, a legacy control field, and a next generation vehicular network (NGV) training field,

   The legacy control field is received through a first symbol, the NGV training field is received through a second symbol successive to the first symbol,

   The first symbol is modulated based on a first constellation, and the second symbol is modulated based on a second constellation rotated based on the first constellation; And

   Set to obtain information on the type of the PPDU based on the first constellation and the second constellation,

   STA.
7. The method of claim 6,

   The NGV training field is used for channel estimation,

   STA.
8. The method of claim 6,

   The PPDU further includes a data field,

   The data field is continuous to the NGV training field,

   STA.
9. The method of claim 6,

   The first constellation is modulated based on binary phase shift keying (BPSK),

   The second constellation is modulated based on Q-BPSK (quadrature BPSK),

   STA.
10. The method of claim 6,

    The second constellation is rotated 90 degrees counterclockwise based on the first constellation,

    STA.
11. In a method performed in a wireless local area network (LAN) system,

    Generating, by a STA (station), a physical protocol data unit (PPDU) including a first legacy training field, a second legacy training field, a legacy control field, and a next generation vehicular network (NGV) training field; And

    Including the step of the STA, transmitting the PPDU,

    The legacy control field is transmitted through a first symbol, the NGV training field is transmitted through a second symbol consecutive to the first symbol,

    The first symbol is modulated based on a first constellation, and the second symbol is modulated based on a second constellation rotated based on the first constellation,

    Way.
12. In the STA (station) used in a wireless local area network (LAN) system, the STA,

    A transceiver for transmitting and receiving a radio signal; And

    Including a processor connected to the transceiver, wherein the processor,

    Generating a physical protocol data unit (PPDU) including a first legacy training field, a second legacy training field, a legacy control field, and a next generation vehicular network (NGV) training field; And

    Transmit the PPDU,

    The legacy control field is transmitted through a first symbol, the NGV training field is transmitted through a second symbol consecutive to the first symbol,

    The first symbol is modulated based on a first constellation, and the second symbol is set to be modulated based on a second constellation rotated based on the first constellation,

    STA.
13. At least one computer readable medium containing instructions based on being executed by at least one processor of an STA (station) of a wireless local area network (LAN) system In ),

    Receiving a PPDU (physical protocol data unit) including a first legacy training field, a second legacy training field, a legacy control field, and a next generation vehicular network (NGV) training field,

    The legacy control field is received through a first symbol, the NGV training field is received through a second symbol successive to the first symbol,

    Wherein the first symbol is modulated based on a first constellation, and the second symbol is modulated based on a second constellation rotated based on the first constellation; And

    Performing an operation including acquiring information on the type of the PPDU based on the first constellation and the second constellation,

    Device.
14. In a device on a wireless local area network (LAN) system,

    Memory; And

    A processor operatively coupled to the memory, wherein the processor:

    Receiving a PPDU (physical protocol data unit) including a first legacy training field, a second legacy training field, a legacy control field, and a next generation vehicular network (NGV) training field,

    The legacy control field is received through a first symbol, the NGV training field is received through a second symbol successive to the first symbol,

    The first symbol is modulated based on a first constellation, and the second symbol is modulated based on a second constellation rotated based on the first constellation; And

    Set to obtain information on the type of the PPDU based on the first constellation and the second constellation,

    Device.

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