WO2021112336A1 - Method for generating ltf sequence - Google Patents

Abstract

In a wireless local area network system, a station (STA) may generate a long training field (LTF) signal. The LTF signal may be generated based on the basis of an LTF sequence for a 320MHz band. The LTF sequence, preset as A sequence, B sequence, and zero sequence, may be defined as {A, zero sequence, B, zero sequence, -A, zero sequence, B}. The STA may transmit a PHY protocol data unit (PPDU) including the LTF signal through the 320MHz band.

Description

How to create an LTF sequence

The present specification relates to a method of configuring a long training field (LTF) sequence for a 320 MHz band in a wireless local area network (WLAN) system.

A wireless local area network (WLAN) has been improved in various ways. For example, the IEEE 802.11ax standard proposes an improved communication environment using OFDMA (orthogonal frequency division multiple access) and DL MU downlink multi-user multiple input, multiple output (MIMO) techniques.

This specification proposes technical features that can be used in a new communication standard. For example, the new communication standard may be the Extreme High Throughput (EHT) specification, which is being discussed recently. The EHT standard may use a newly proposed increased bandwidth, an improved PHY layer protocol data unit (PPDU) structure, an improved sequence, a hybrid automatic repeat request (HARQ) technique, and the like. The EHT standard may be referred to as an IEEE 802.11be standard.

A method performed by a station (STA) in a wireless local area network (WLAN) system according to various embodiments may include a technical feature of transmitting an LTF signal based on an LTF sequence for a 320 MHz band. A station (STA) may generate a long training field (LTF) signal. The LTF signal may be generated based on the LTF sequence for the 320 MHz band. The LTF sequence may be defined as {A, zero sequence, B, zero sequence, -A, zero sequence, B} as a preset A sequence, B sequence, and zero sequence. The STA may transmit a PHY protocol data unit (PPDU) including the LTF signal through the 320 MHz band.

According to an example of the present specification, the sequence for the 320 MHz band may be generated by reusing the previously defined sequence for the 160 MHz. The sequence for the 320 MHz band can reduce hardware complexity by reusing a high efficiency long training field (HE-LTF) used for IEEE802.11ax. According to an example of the present specification, the LTF symbol may have a low peak to average power ratio (PAPR). Accordingly, communication performance may be improved.

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

2 is a conceptual diagram illustrating the structure of a wireless local area network (WLAN).

3 is a view for explaining a general link setup process.

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

5 is a diagram illustrating an arrangement of resource units (RUs) used on a 20 MHz band.

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

7 is a diagram illustrating an arrangement of a resource unit (RU) used on an 80 MHz 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 technique.

10 shows an operation according to 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 illustrates the technical features of the UORA technique.

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

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

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

18 shows an example of a PPDU used in this specification.

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

20 is a diagram illustrating PAPR for each RU when the LTF sequence of Equation 6 is used.

21 is a diagram illustrating a cumulative distribution function (CDF) of PAPR for data.

22 is a diagram illustrating PAPR for each RU when the LTF sequence of Equation 15 is used.

23 is a flowchart illustrating an embodiment of an operation of a transmitting STA.

24 is a flowchart illustrating an embodiment of an operation of a receiving STA.

In this 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, “A, B or C(A, B or C)” herein means “only A”, “only B”, “only C”, or “any and any combination of A, B and C ( any combination of A, B and C)”.

A slash (/) or a comma (comma) used herein 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”.

As used herein, “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”.

Also, as used herein, “at least one of A, B and C” means “only A”, “only B”, “only C”, or “A, B and C” Any combination of A, B and C”. Also, “at least one of A, B or C” or “at least one of A, B and/or C” means may mean “at least one of A, B and C”.

In addition, parentheses used herein 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 proposed as an example of “control information”. Also, even when displayed as “control information (ie, EHT-signal)”, “EHT-signal” may be proposed as an example of “control information”.

In this specification, technical features that are individually described within one drawing may be implemented individually or simultaneously.

The following examples of the present specification may 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, the present specification may be applied to the IEEE 802.11a/g/n/ac standard or the IEEE 802.11ax standard. In addition, this specification may be applied to a 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 a new wireless LAN standard that is an enhancement of IEEE 802.11be. Also, an example of the present specification may be applied to a mobile communication system. For example, it may be applied to a mobile communication system based on Long Term Evolution (LTE) based on the 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 the 5G NR standard based on the 3GPP standard.

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

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

The example of FIG. 1 may perform various technical features described below. 1 relates to at least one STA (station). For example, the STAs 110 and 120 of the present specification are a mobile terminal, a wireless device, a wireless transmit/receive unit (WTRU), a user equipment (UE), It may also be called by various names such as a mobile station (MS), a mobile subscriber unit, or simply a user. The 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. In the present specification, the STAs 110 and 120 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 this 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. For example, a communication standard (eg, LTE, LTE-A, 5G NR standard) according to the 3GPP standard may be supported. In addition, the STA of the present specification may be implemented in 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) conforming to the IEEE 802.11 standard and a physical layer interface for a wireless medium.

The STAs 110 and 120 will be described based on 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 one 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.) may be transmitted/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 the 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 to be transmitted through the transceiver (ie, a transmission signal).

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

For example, the processor 121 of the non-AP STA may receive a signal through the transceiver 123 , process the 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 received signal) received through the transceiver 123 and may store a signal (ie, a transmission signal) to be transmitted through the transceiver.

For example, an operation of a device denoted as an AP in the following specification 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 marked as AP is controlled by the processor 111 of the first STA 110 , and is controlled by the processor 111 of the first STA 110 . Related signals may be transmitted or received via the controlled transceiver 113 . In addition, control information related to an 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 by the 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 via the transceiver 123 . In addition, control information related to an operation of the AP or a transmission/reception signal of the AP may be stored in the memory 122 of the second STA 110 .

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

In the following specification (transmission / reception) STA, first STA, second STA, STA1, STA2, AP, first AP, second AP, AP1, AP2, (transmission / reception) Terminal, (transmission / reception) device , (transmission/reception) apparatus, network, and the like may refer to the STAs 110 and 120 of FIG. 1 . For example, without specific reference numerals (transmitting/receiving) STA, first STA, second STA, STA1, STA2, AP, first AP, second AP, AP1, AP2, (transmitting/receiving) Terminal, (transmitting) A device indicated by a /receiver) device, a (transmit/receive) apparatus, and a network may also refer to 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 a transmit/receive signal or perform data processing or calculation in advance for the transmit/receive signal 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 operation in advance for a transmission/reception signal is 1) Determining bit information of a subfield (SIG, STF, LTF, Data) field included in a PPDU /Acquisition/configuration/computation/decoding/encoding operation, 2) time resource or frequency resource (eg, subcarrier resource) used for the subfield (SIG, STF, LTF, Data) field included in the PPDU, etc. operation of determining / configuring / obtaining, 3) a specific sequence (eg, pilot sequence, STF / LTF sequence, SIG) used for the subfield (SIG, STF, LTF, Data) field included in the PPDU operation of determining / configuring / obtaining an extra sequence), etc., 4) a power control operation and / or a power saving operation applied to the STA, 5) an operation related to determination / acquisition / configuration / operation / decoding / encoding of the ACK signal may include In addition, in the following example, various information used by various STAs for determination/acquisition/configuration/computation/decoding/encoding of transmit/receive signals (for example, information related to fields/subfields/control fields/parameters/power, etc.) may be stored in the memories 112 and 122 of FIG. 1 .

The device/STA of the sub-view (a) of FIG. 1 described above may be modified as shown in the sub-view (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 (b) of FIG. 1 may perform the same function as the transceivers illustrated in (a) of FIG. 1 . For example, the processing chips 114 and 124 illustrated in (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 shown in (b) of FIG. 1 are the processors 111 and 121 and the memories 112 and 122 shown in (a) of FIG. ) can perform the same function.

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

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

Referring to (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 . Software code 115, 125 may be included in a variety of programming languages.

The processors 111 and 121 or the processing chips 114 and 124 shown in FIG. 1 may include an application-specific integrated circuit (ASIC), other chipsets, logic circuits, and/or data processing devices. 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 may include a digital signal processor (DSP), a central processing unit (CPU), a graphics processing unit (GPU), and a modem (Modem). and demodulator). For example, the processors 111 , 121 or processing chips 114 , 124 shown in FIG. 1 may include a SNAPDRAGON™ series processor manufactured by Qualcomm®, an EXYNOSTM series processor manufactured by Samsung®, and a processor manufactured by Apple®. 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.

In this specification, the uplink may mean a link for communication from the non-AP STA to the AP STA, and an uplink PPDU/packet/signal may be transmitted through the uplink. In addition, in the present specification, 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 illustrating the structure of a wireless local area network (WLAN).

The upper part of FIG. 2 shows the structure of an infrastructure basic service set (BSS) of the Institute of Electrical and Electronic Engineers (IEEE) 802.11.

Referring to the upper part of FIG. 2 , a wireless LAN system may include one or more infrastructure BSSs 200 and 205 (hereinafter, BSSs). The BSSs 200 and 205 are a set of APs and STAs, such as an access point (AP) 225 and a station 200-1 (STA1) that can communicate with each other through successful synchronization, and are not a concept indicating a specific area. The BSS 205 may include one or more combinable STAs 205 - 1 and 205 - 2 to one AP 230 .

The BSS may include at least one STA, the 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 that is an extended service set by connecting several BSSs 200 and 205 . The ESS 240 may be used as a term indicating one network in which one or several APs are connected 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 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 also be possible to establish a network and perform communication between STAs without the APs 225 and 230 . A network that establishes a network and performs communication 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 illustrating the IBSS.

Referring to the lower part of FIG. 2 , the IBSS is a BSS operating in an ad-hoc mode. Since IBSS does not include an AP, there is no centralized management entity that performs a centralized management function. 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 mobile STAs, and access to a distributed system is not allowed, so a self-contained network network) is formed.

3 is a view for explaining 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 in which it can participate. An STA must identify a compatible network before participating in a 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 exemplarily illustrates a network discovery operation including an active scanning process. In active scanning, an STA performing scanning transmits a probe request frame to discover which APs exist around it while moving channels, and waits for a response. A 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 the STA that last transmitted a beacon frame in the BSS of the channel being scanned. In the BSS, since the AP transmits a beacon frame, the AP becomes the responder. In the IBSS, the STAs in the IBSS rotate and transmit the beacon frame, so the responder is not constant. 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 channel) to perform scanning (ie, probe request/response transmission/reception on channel 2) in the same way.

Although not shown in the example of FIG. 3 , the scanning operation may be performed in a passive scanning manner. 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 to inform the existence of a wireless network, and to allow a scanning STA to search for a wireless network and participate in the wireless network. In the BSS, the AP plays a role of periodically transmitting a beacon frame, and in the 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 and records the beacon frame information in each channel while moving to another channel. Upon receiving the beacon frame, the STA may store BSS-related information included in the received beacon frame, move to the next channel, and perform scanning on the next channel in the same manner.

The STA discovering the network may perform an authentication process through step SS320. 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 an authentication request/response corresponds to a management frame.

The authentication frame includes an authentication algorithm number, an authentication transaction sequence number, a status code, a challenge text, a Robust Security Network (RSN), and a Finite Cyclic Group), etc. may 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 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 successfully authenticated STA 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, the AP transmits an association response frame to the STA. For example, the connection request frame includes information related to various capabilities, a beacon listening interval, a service set identifier (SSID), supported rates, supported channels, RSN, and a mobility domain. , supported operating classes, TIM broadcast request (Traffic Indication Map Broadcast request), interworking service capability, and the like may include information. 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 Indicator (RCPI), Received Signal to Noise (RSNI). indicator), mobility domain, timeout interval (association comeback time), overlapping BSS scan parameters, TIM broadcast response, QoS map, and the like.

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 private key setup through 4-way handshaking through an Extensible Authentication Protocol over LAN (EAPOL) frame. .

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

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

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. HE-SIG-B may be included only for multiple users, and the corresponding HE-SIG-B may be omitted from the PPDU for a single user.

As shown, HE-PPDU for multiple users (Multiple User; 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 interval (ie, 4 or 8 μs, etc.).

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

5 is a diagram illustrating an arrangement of resource units (RUs) used on 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 RUs 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 deployed. Six tones may be used as a guard band in the leftmost band of the 20 MHz band, and 5 tones may be used as a guard band in the rightmost band of the 20 MHz band. In addition, 7 DC tones are inserted into the center band, that is, the DC band, and 26-units corresponding to each of 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 may be assigned for a receiving station, ie a user.

On the other hand, 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 at 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, ie, 26-RU, 52-RU, 106-RU, 242-RU, etc., have been proposed. Since the specific size of these RUs can be extended or increased, this embodiment is not limited to the specific size of each RU (ie, the number of corresponding tones).

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

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

Also, as shown, when used for a single user, 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 illustrating an arrangement of a resource unit (RU) used on an 80 MHz band.

As in the example of FIGS. 5 and 6 , RUs of various sizes are used, in the example of FIG. 7, 26-RU, 52-RU, 106-RU, 242-RU, 484-RU, 996-RU, etc. may be used. have. In addition, 7 DC tones can be inserted into the center frequency, 12 tones are used as a guard band in the leftmost band of the 80MHz band, and 11 tones are used in the rightmost band of the 80MHz band. This 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.

Also, as shown, when used for a single user, 996-RU may be used, and in this case, 5 DC tones may be inserted.

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

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

One RU in this 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 in this specification may be used for uplink (UL) communication and downlink (DL) communication. For example, when UL-MU communication solicited by a Trigger frame is performed, a transmitting STA (eg, AP) provides a first RU (eg, 26/52/106) to the first STA through a 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 PPDUs are transmitted to the AP in the same time interval.

For example, when the 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 A second RU (eg, 26/52/106/242-RU, etc.) may be allocated to the 2 STAs. 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 through the second RU. HE-STF, HE-LTF, and Data fields for 2 STAs may 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 SIG-B. The user-individual field 830 may be referred to as a user-individual control field. The user-individual field 830 may be applied only to some of the plurality of users when the SIG-B is delivered to a plurality of users.

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

The common field 920 may include N*8 bits of RU allocation information. For example, the RU allocation information may include information about 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 disposed in which frequency band. .

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

As in the example of FIG. 5 , a maximum of nine 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 thereof.

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

For example, the 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 side of a 20 MHz channel, and 5 26-RUs are allocated to the right side thereof. In this case, a plurality of STAs (eg, User-STAs) may be allocated to the 106-RU based on the MU-MIMO technique. Specifically, a maximum of 8 STAs (eg, User-STAs) may be allocated to the 106-RU, and the number of STAs (eg, User-STAs) allocated to the 106-RU is 3-bit information (y2y1y0). ) is determined based on For example, when 3-bit information (y2y1y0) is set to N, the number of STAs (eg, User-STAs) allocated to the 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, a plurality of STAs (eg, user STAs) may be allocated to one RU of a specific size (eg, 106 subcarriers) or more 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 of 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 the nine 26-RUs (that is, a total of nine user STAs are allocated). That is, a maximum of 9 user STAs may be allocated to a specific channel through the OFDMA technique. In other words, up to 9 user STAs may be allocated to a specific channel through the non-MU-MIMO technique.

For example, if the RU allocation is set to “01000y2y1y0”, a plurality of User STAs are allocated to the 106-RU disposed on the left-most side through the MU-MIMO technique, and the five 26-RUs disposed on the right side have Five user STAs may be allocated through the non-MU-MIMO technique. 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 technique.

For example, if RU allocation is set to “01000010” as shown in FIG. 9, based on Table 2, 106-RU is allocated to the leftmost side of a specific channel and 5 26-RUs are allocated to the right side of the channel. can In addition, a total of three user STAs may be allocated to the 106-RU through the MU-MIMO technique. 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 . Also, 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, the user field related to the MU-MIMO technique may be configured in the first format, and the user field related to the non-MU-MIMO technique may be configured in the 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 technique) may be configured as follows.

For example, the first bit (eg, B0-B10) in the user field (ie, 21 bits) is identification information of the user STA to which the corresponding user field is allocated (eg, STA-ID, partial AID, etc.) may include. In addition, the second bit (eg, B11-B14) in the user field (ie, 21 bits) may include information about spatial configuration. Specifically, examples of the second bits (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 (ie, B11-B14) may include information about the number of spatial streams allocated to a plurality of user STAs allocated according to the MU-MIMO technique. 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, as shown in Table 3, N_STS[1], Values of N_STS[2] and N_STS[3] may be determined. For example, when the value of the second bits B11-B14 is “0011”, N_STS[1]=4, N_STS[2]=1, N_STS[3]=1 may be set. That is, in the example of FIG. 9 , four spatial streams may be allocated to user field 1, one spatial stream may be allocated to user field 2, and one spatial stream may be allocated to user field 3 in the example of FIG.

As an example of Table 3 and/or Table 4, information about the number of spatial streams for a user STA (ie, the second bit, B11-B14) may consist of 4 bits. In addition, information on the number of spatial streams (ie, second bits, B11-B14) for a user STA may support up to 8 spatial streams. In addition, information on the number of spatial streams (ie, the second bit, B11-B14) may support up to four spatial streams for one user STA.

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

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

Also, the fourth bit (ie, B19) in the User field (ie, 21 bits) may be a Reserved field.

In addition, a fifth bit (ie, B20) in the user field (ie, 21 bits) may include information about a 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 technique). An example of the user field of the second format (a format of the non-MU-MIMO technique) 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 about 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 a beamforming steering matrix is applied. A fourth bit (eg, B15-B18) in the user field of the second format may include modulation and coding scheme (MCS) information. In addition, a fifth bit (eg, B19) in the user field of the second format may include information on whether Dual Carrier Modulation (DCM) is applied. In addition, the sixth bit (ie, B20) in the user field of the second format may include information about a coding type (eg, BCC or LDPC).

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

The TB PPDUs 1041 and 1042 are transmitted in the same time zone, and may be transmitted from a plurality of STAs (eg, user STAs) in which AIDs are indicated in the trigger frame 1030 . The ACK frame 1050 for the TB PPDU may be implemented in various forms.

Specific features 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 MU MIMO technique may be used, and OFDMA and MU MIMO technique may 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, for example, from an AP. The trigger frame may be composed of a MAC frame and may be included in a PPDU.

Each field shown in FIG. 11 may be partially omitted, and another field 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 about the version of the MAC protocol and other additional control information, and the duration field 1120 includes time information for NAV setting or an STA identifier (eg, For example, information about 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, AP) that transmits the trigger frame, and the common information field 1150 is a common information field applied to the receiving STA that receives the trigger frame. Contains control information. For example, a field indicating the length of the L-SIG field of the uplink PPDU transmitted in response to the trigger frame or the SIG-A field (ie, HE-SIG-A) in the uplink PPDU transmitted in response to the trigger frame. field) may include information controlling the content. In addition, as common control information, information on the length of the CP of the uplink PPDU transmitted in response to the trigger frame or information on the length of the LTF field may be included.

In addition, it is preferable to include per 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 “allocation field”.

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

Each of the per 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. Also, the length of each subfield shown 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 trigger frame, and the length field of the L-SIG field of the uplink PPDU indicates 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.

In addition, 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 the case cade operation, there may be only one transmitter (eg, AP) performing downlink communication, and a plurality of transmitters (eg, non-AP) performing uplink communication may exist.

The CS request field 1230 indicates whether the state of the radio medium or NAV should be considered 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 LTF length and 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, a request for Block ACK/NACK, and the like.

In the present specification, it may be assumed that the trigger type field 1260 of the trigger frame indicates a basic type 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 one 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. Also, the length of each subfield shown 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 a 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 in response 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 is set to '1', and when LDPC coding is applied, the coding type field 1330 can be set to '0'. have.

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

Hereinafter, a UL OFDMA-based random access (UORA) technique will be described.

14 illustrates 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 on 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 non-associated for 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 OFDMA random access BackOff (OBO) counter of STA1 is decreased 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, in FIG. 14 , STA4 includes its AID (ie, AID=3) in the trigger frame, and thus the resource of RU 6 is 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 decrements the OBO counter by 3 to increase the OBO counter. became 0. In addition, since STA2 in FIG. 14 is an associated STA, there are a total of three eligible RA RUs for STA2 (RU 1, RU 2, RU 3), and accordingly, STA2 decrements 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, the eligible RA RUs for STA3 are two (RU 4, RU 5) in total, and accordingly, STA3 decrements the OBO counter by 2, but the OBO counter is is greater than 0.

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

The 2.4 GHz band may be referred to as another name such as a first band (band). Also, the 2.4 GHz band may mean a frequency region in which channels having a center frequency adjacent to 2.4 GHz (eg, channels having a center frequency 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 indices (eg, indices 1 to 14). For example, a center frequency of a 20 MHz channel to which channel index 1 is allocated may be 2.412 GHz, a center frequency of a 20 MHz channel to which channel index 2 is allocated may be 2.417 GHz, and 20 MHz to which channel index N is allocated. The center frequency of the channel may be (2.407 + 0.005*N) GHz. The channel index may be called by various names such as a channel number. Specific values of the channel index and center frequency may be changed.

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

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

The 5 GHz band may be referred to as another name such as a second band/band. The 5 GHz band may mean a frequency region 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 numerical 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 may be referred to as UNII Low. UNII-2 may include a frequency domain called UNII Mid and UNII-2Extended. UNII-3 may be referred to as UNII-Upper.

A plurality of channels may be configured within the 5 GHz band, and the bandwidth of each channel may be variously configured such as 20 MHz, 40 MHz, 80 MHz, or 160 MHz. For example, the 5170 MHz to 5330 MHz frequency region/range in UNII-1 and UNII-2 may be divided into eight 20 MHz channels. The 5170 MHz to 5330 MHz frequency domain/range may be divided into 4 channels through the 40 MHz frequency domain. The 5170 MHz to 5330 MHz frequency domain/range may 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 the 6 GHz band.

The 6 GHz band may be referred to as another name such as a third band/band. The 6 GHz band may mean a frequency region in which channels having a center frequency of 5.9 GHz or higher are used/supported/defined. The specific numerical 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 among the 20 MHz channels of FIG. 17 may have an index 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 channel index N may be determined to be (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, 165, 169, 173, 177, 181, 185, 189, 193, 197, 201, 205, 209, 213, 217, 221, 225, 229, 233. In addition, according to the above-mentioned (5.940 + 0.005*N) GHz rule, the index of the 40 MHz channel of 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.

Although 20, 40, 80, and 160 MHz channels are illustrated in the example of FIG. 17 , a 240 MHz channel or a 320 MHz channel may be additionally 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 this specification.

The PPDU of FIG. 18 may be referred to by various names such as an EHT PPDU, a transmission PPDU, a reception PPDU, a first type or an Nth type PPDU. In addition, it can be used in an EHT system and/or a new WLAN system in which the EHT system is improved.

The subfield 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, the SIG B field may be referred to as EHT-SIG-B, the STF field may be referred to as an EHT-STF field, and the 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 indices of the L-LTF, L-STF, L-SIG, and RL-SIG fields may be displayed in units of 312.5 kHz, and the subcarrier indices of the STF, LTF, and Data fields may be expressed 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.). All/part of the subcarrier spacing of all/part of the SIG A and SIG B fields and all/part of the additionally defined SIG field may be set to 312.5 kHz. Meanwhile, the subcarrier spacing for a part of the newly defined SIG field may be determined as a preset value (eg, 312.5 kHz or 78.125 kHz).

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

The L-SIG field of FIG. 18 may include, for example, 24-bit bit information. For example, 24-bit information may include a 4-bit Rate field, a 1-bit Reserved bit, a 12-bit Length field, a 1-bit Parity bit, and a 6-bit Tail bit. For example, a 12-bit Length field may include information about 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 the PPDU. For example, when the PPDU is a non-HT, HT, VHT PPDU or an 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 “a multiple of 3 + 1” or “a multiple of 3 +2”. In other words, for a non-HT, HT, VHT PPDU or for an EHT PPDU, the value of the Length field may be determined as a multiple of 3, and for an HE PPDU, the value of the Length field may be “a multiple of 3 + 1” or “a multiple of 3” +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 encoding bit. BPSK modulation may be applied to 48-bit coded bits to generate 48 BPSK symbols. The transmitting STA may map 48 BPSK symbols to positions excluding pilot subcarriers {subcarrier indexes -21, -7, +7, +21} and DC subcarriers {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 signals of {-1, -1, -1, 1} to the subcarrier indexes {-28, -27, +27, +28}. The above signal may 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 way as the L-SIG. For RL-SIG, BPSK modulation may be applied. The receiving STA may know that the received PPDU is an HE PPDU or an EHT PPDU based on the existence of the RL-SIG.

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

A symbol consecutive to the RL-SIG (eg, U-SIG) may include information of N bits, and may include information for identifying the type of the 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 the U-SIG may be used to transmit 26-bit information. For example, each symbol of the U-SIG may be transmitted/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 the 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 the remaining Y-bit information (eg, 26 un-coded bits) of the total A-bit information. have. For example, the transmitting STA may obtain 26 un-coded bits included in each U-SIG symbol. The transmitting STA may perform convolutional encoding based on a rate of R=1/2 to generate a 52-coded bit and 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 except for DC index 0. The 52 BPSK symbols generated by the transmitting STA may be transmitted based on the remaining tones (subcarriers) excluding pilot tones -21, -7, +7, and +21 tones.

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

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, the version-independent bits may be allocated only to the first symbol of the U-SIG, or the version-independent bits may be allocated to both the first symbol and the second symbol of the U-SIG. For example, the version-independent bits and the 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 the 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 the 3-bit PHY version identifier to the first value. In other words, the receiving STA may determine that the receiving PPDU is an EHT PPDU based on the PHY version identifier having the first value.

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

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

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

For example, the U-SIG field includes 1) a bandwidth field including information on bandwidth, 2) a field including information on an MCS technique applied to SIG-B, 3) dual subcarrier modulation in SIG-B ( An indication field including information on whether dual subcarrier modulation) is applied, 4) a field including information on 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 about the LTF/STF type, and 7) information about a field indicating the length of the LTF and the CP length.

The SIG-B of FIG. 18 may include the technical features of the HE-SIG-B shown in the examples 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 to various types. For example, the first type of STF (ie, 1x STF) may be generated based on the first type STF sequence in which non-zero coefficients are disposed at intervals of 16 subcarriers. 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 the first type STF having a length of 4 µs. For example, the second type of STF (ie, 2x STF) may be generated based on the second type STF sequence in which non-zero coefficients are disposed at intervals of 8 subcarriers. The STF signal generated based on the second type STF sequence may have a cycle of 1.6 μs, and the cycle signal of 1.6 μs may be repeated 5 times to become a second type EHT-STF having a length of 8 μs. For example, the third type of STF (ie, 4x EHT-STF) may be generated based on a third type STF sequence in which non-zero coefficients are disposed at intervals of 4 subcarriers. The STF signal generated based on the third type STF sequence may have a period of 3.2 µs, and the 3.2 µs period signal 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 types of EHT-STF sequences may be used. In addition, the EHT-LTF field may have a first, second, and third type (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 disposed at intervals of 4/2/1 subcarriers. 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 the 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 a plurality of receiving STAs of the PPDU of FIG. 18 (that is, when an MU PPDU is used), some fields (eg, STF, LTF, data) of FIG. 18 are shown in FIGS. 5 to 7 and the like. 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/received through the first RU, and the STF, LTF, and data fields for the second receiving STA of the PPDU are transmitted/received through the second RU can be In this case, the positions of the first/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 receiving PPDU as an 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) the RL-SIG where the L-SIG of the received PPDU is repeated is detected, 3) the L-SIG of the received PPDU is Length 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 it is determined that the received PPDU is an EHT PPDU, the receiving STA determines the type of the EHT PPDU (eg, SU/MU/Trigger-based/Extended Range type based on bit information included in the symbols after the RL-SIG of FIG. AX18). ) can be detected. In other words, the receiving STA 1) the first symbol after the L-LTF signal that is BSPK, 2) RL-SIG that is continuous to the L-SIG field and is the same as the L-SIG, 3) The result of applying “modulo 3” is “ L-SIG including a Length field set to 0”, and 4) based on the 3-bit PHY version identifier of the above-described U-SIG (eg, PHY version identifier having a first value), receive PPDU It can be determined as an EHT PPDU.

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

In the example below, (transmit/receive/uplink/downlink) signals, (transmit/receive/uplink/downlink) frames, (transmit/receive/uplink/downlink) packets, (transmit/receive/uplink/downlink) data units, ( A signal indicated by transmission/reception/uplink/downlink) data, etc. 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. Examples of the control frame may include request to send (RTS), clear to send (CTS), Power Save-Poll (PS-Poll), BlockACKReq, BlockAck, Null Data Packet (NDP) announcement, and Trigger Frame. For example, the PPDU of FIG. 18 may be used for a management frame. An example of the management frame may include a Beacon frame, a (Re-)Association Request frame, a (Re-)Association Response frame, a Probe Request frame, and a 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 a transmitting apparatus and/or a receiving apparatus of the present specification.

Each device/STA of the 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 the result processed by the processor 610 . Keypad 614 receives input to be used by processor 610 . A keypad 614 may be displayed on the display 613 . SIM card 615 may be an integrated circuit used to securely store an international mobile subscriber identity (IMSI) used to identify and authenticate subscribers in mobile phone devices, such as mobile phones and computers, and keys associated therewith. .

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

A transmitting station (STA) may generate a long training field (LTF) signal. The LTF signal may be generated based on the LTF sequence for the 320 MHz band. The LTF sequence may be defined as a preset A sequence, a B sequence, and a zero sequence as follows.

{A, zero sequence, B, zero sequence, -A, zero sequence, B}

For example, the LTF sequence may be defined by Equation 6, 15, 21, or 22. The zero sequence zeros(1,23) may be a sequence in which zeros are mapped to 23 consecutive tones. The A sequence and the B sequence may be an LTF sequence for an 80 MHz band. The LTF sequence may be mapped from a lowest tone having a tone index of -2036 to a highest tone having a tone index of 2036. The A sequence and the B sequence may each consist of 1001 tones. The transmitting STA may transmit a PHY protocol data unit (PPDU) including the LTF signal through a 320 MHz band.

A long training field (LTF) sequence for the 320 MHz band may be defined by reusing an LTF sequence transmitted at 160 MHz previously defined in IEEE802.11ax. When a 320 MHz sequence is generated by reusing a high efficiency long training field (HE-LTF) used for IEEE802.11ax, the sequence for the 320 MHz band may not need to be separately stored in a memory. Since a 320 MHz sequence can be generated by reusing a HE-LTF sequence stored for IEEE802.11ax or a module used to generate a HE-LTF sequence, there is an effect of lowering hardware complexity. Even in the standard, an extremely high throughput-LTF (EHT-LTF) sequence for a 320 MHz band can be defined using an existing 160 MHz sequence without the need to separately configure a new sequence.

A 4x EHT-LTF sequence for a 320 MHz bandwidth to support IEEE802.11be may be defined as in Equation 1.

Referring to Equation 1, the 4x EHT-LTF sequence _{may be configured based on a low 160MHz 4x LTF sequence (LTF 160MHz_lower_4x} ) and a high 160MHz 4x LTF sequence (LTF _{160MHz _upper_4x} ), and a zero sequence. For example, a 4x EHT-LTF sequence may be mapped from tone index -2036 to tone index 2036. The zero sequence zeroes(1, 23) may be a sequence in which zeros are mapped to 23 consecutive tones.

The low 160MHz 4x LTF sequence may be constructed based on a low 80MHz 4x LTF sequence (LTF _{80MHz _lower_4x} ), a high 80MHz 4x LTF sequence (LTF _{80MHz _upper_4x} ), and a zero sequence. The high 160 MHz 4x LTF sequence may be constructed based on the low 80 MHz 4x LTF sequence, the high 80 MHz 4x LTF sequence, and the zero sequence. The low 80MHz 4x LTF sequence and the high 80MHz 4x LTF sequence may be sequences defined in IEEE802.11ax.

The low 80MHz 4x LTF sequence and the high 80MHz 4x LTF sequence may be sequences based on Equations 2 to 5.

On the other hand, the sequence shown in Equation 1 may have a relatively high peak to average power ratio (PAPR) due to the repetition characteristic. Therefore, in order to lower the PAPR, as shown in Equation 6, a phase rotation may be performed on a specific sequence set among the EHT-LTF sequences.

The EHT-LTF sequence of Equation 6 has a PAPR of 7.09 dB. The EHT-LTF sequence of Equation 6 is a sequence in which the phase of the low 80MHz LTF sequence (LTF _{80MHz_lower_4x ) of the high 160MHz LTF sequence (LTF 160MHz_upper_4x) in the EHT-LTF sequence of Equation 1 is rotated.} The EHT-LTF sequence of Equation 6 can obtain a PAPR gain by 0.1 dB than the sequence in which the phase of the high 80MHz LTF sequence (LTF _{80MHz_upper_4x ) of the high 160MHz LTF sequence (LTF 160MHz_upper_4x) is rotated.}

When a transmitting STA (access point (AP) or non-AP STA) transmits an LTF using an MU multi-user PPDU (MU PPDU), since the receiving STA can receive the LTF only in a specific resource unit (RU), each RU PAPR should be considered.

20 is a diagram illustrating PAPR for each RU when the LTF sequence of Equation 6 is used.

Referring to FIG. 20 , the horizontal axis represents frequency (or tone, subcarrier, etc.). 26 RU (2010, 2011, 2012), 52 RU (2020, 2021), 108 RU (2030, 2031, 2032, 2033), 242 RU (2040), 484 RU (2050), 996 RU (2060) are shown have. 20 shows only RUs for an 80 MHz bandwidth for convenience, three more RU sets having the same configuration may exist. That is, there are a total of four RU sets for the 80 MHz bandwidth to configure the RU set for the 320 MHz bandwidth. Two 2x996 RUs 2070 for 160 MHz bandwidth may exist, and one 4x996 RU 2080 for 320 MHz bandwidth may exist.

The number indicated in the block indicates the PAPR when the LTF sequence is transmitted through the corresponding RU. Even for the same RU, the PAPR value may vary depending on the location. For example, 52 RU 2020 may have a PAPR of 4.97 and 52 RU 2021 may have a PAPR of 4.44. For example, 108 RU 2030 may have a PAPR of 5.38, 108 RU 2031 may have a PAPR of 5.35, 108 RU 2032 may have a PAPR of 5.31, and 108 RU 2033 may have a PAPR of 5.53. For example, 26 RU (2012) is 4.25 in the RU set for the first 80 MHz bandwidth, 4.43 in the RU set for the second 80 MHz bandwidth, 4.25 in the RU set for the third 80 MHz bandwidth, and RU for the fourth 80 MHz bandwidth. In the set, it can have a PAPR of 4.43. For example, 996 RU 2060 is 6.29 in the RU set for the first 80 MHz bandwidth, 7.22 in the RU set for the second 80 MHz bandwidth, 6.29 in the RU set for the third 80 MHz bandwidth, and RU for the fourth 80 MHz bandwidth. The set can have a PAPR of 7.22. For example, the 2x996 RU 2070 may have a PAPR of 7.09 in the RU set for the first 160 MHz bandwidth and 7.20 in the RU set for the second 160 MHz bandwidth. For example, a 4x996 RU 2080 may have a PAPR of 7.09.

21 is a diagram illustrating a cumulative distribution function (CDF) of PAPR for data.

21 shows PAPR values when BPSK and QAM are used in a 320 MHz bandwidth, respectively. Referring to FIG. 21 , it can be seen that the median value of PAPR exceeds 9 dB.

Table 5 is a table showing the PAPR median of data for each RU size.

Referring back to FIG. 20 , the PAPR value of the LTF sequence of Equation 6 is smaller than the median value of the PAPR of the data based on FIGS. 21 and Table 5 . Since the LTF sequence of Equation 6 has a lower PAPR than the median PAPR of the data even considering RUs of all sizes, it can be considered that the LTF sequence has reasonable PAPR characteristics in RUs of all sizes.

A 2x EHT-LTF sequence for a 320 MHz bandwidth to support IEEE802.11be may be defined as in Equation 7.

Referring to Equation 7, 2x EHT-LTF sequence may be constructed on the basis of the lower 160MHz sequence LTF (LTF _{160MHz_lower_2x)} with high sequence 160MHz LTF (LTF _{160MHz _upper_2x),} and zero sequence. For example, a 2x EHT-LTF sequence may be mapped from tone index -2036 to tone index 2036. The zero sequence zeroes(1, 23) may be a sequence in which zeros are mapped to 23 consecutive tones.

The low 160MHz 2x LTF sequence may be constructed based on a low 80MHz 2x LTF sequence (LTF _{80MHz _lower_2x} ), a high 80MHz 2x LTF sequence (LTF _{80MHz _upper_2x} ), and a zero sequence. The high 160 MHz 2x LTF sequence may be constructed based on the low 80 MHz 2x LTF sequence, the high 80 MHz 2x LTF sequence, and the zero sequence. The low 80MHz 2x LTF sequence and the high 80MHz 2x LTF sequence may be sequences defined in IEEE802.11ax.

The low 80MHz 2x LTF sequence and the high 80MHz 2x LTF sequence may be sequences based on Equations (8) to (14).

On the other hand, the sequence shown in Equation 7 may have a relatively high peak to average power ratio (PAPR) due to the repetition characteristic. Therefore, in order to lower PAPR, as shown in Equation 15, phase rotation may be performed on a specific sequence set among the EHT-LTF sequences.

The EHT-LTF sequence of Equation 15 has a PAPR of 6.69 dB. The EHT-LTF sequence of Equation 15 is a sequence in which the phase of the low 80MHz 2x LTF sequence (LTF _{80MHz_lower_2x ) of the high 160MHz 2x LTF sequence (LTF 160MHz_upper_2x) in the EHT-LTF sequence of Equation 7 is rotated.} The EHT-LTF sequence of Equation 15 can obtain a PAPR gain by 0.5dB than a sequence in which the phase of the high 80MHz 2x LTF sequence (LTF _{80MHz_upper_2x ) of the high 160MHz 2x LTF sequence (LTF 160MHz_upper_2x) is rotated.}

When a transmitting STA (access point (AP) or non-AP STA) transmits an LTF using an MU multi-user PPDU (MU PPDU), since the receiving STA can receive the LTF only in a specific resource unit (RU), each RU PAPR should be considered.

22 is a diagram illustrating PAPR for each RU when the LTF sequence of Equation 15 is used.

Referring to FIG. 22 , the horizontal axis represents frequency (or tone, subcarrier, etc.). 26 RU ( 2210 , 2211 , 2212 ), 52 RU ( 2220 ), 108 RU ( 2230 ), 242 RU ( 2240 ), 484 RU ( 2250 , 2251 ), and 996 RU ( 2260 ) are shown. 22 shows only RUs for an 80 MHz bandwidth for convenience, three more RU sets having the same configuration may exist. That is, there are a total of four RU sets for the 80 MHz bandwidth to configure the RU set for the 320 MHz bandwidth. Two 2x996 RUs 2270 for 160 MHz bandwidth may exist, and one 4x996 RU 2280 for 320 MHz bandwidth may exist.

The number indicated in the block indicates the PAPR when the LTF sequence is transmitted through the corresponding RU. Even for the same RU, the PAPR value may vary depending on the location. For example, 484 RUs 2250 are 6.33 in the RU set for the first 80 MHz bandwidth, 6.40 in the RU set for the second 80 MHz bandwidth, 6.33 in the RU set for the third 80 MHz bandwidth, and the fourth 80 MHz. The RU set for bandwidth may have a PAPR of 6.40. For example, 484 RU 2251 is 6.40 in the RU set for the first 80 MHz bandwidth, 6.33 in the RU set for the second 80 MHz bandwidth, 6.40 in the RU set for the third 80 MHz bandwidth, and RU for the fourth 80 MHz bandwidth. In the set, it can have a PAPR of 6.33. For example, 996 RU 2260 is 6.09 in the RU set for the first 80 MHz bandwidth, 6.69 in the RU set for the second 80 MHz bandwidth, 6.09 in the RU set for the third 80 MHz bandwidth, and RU for the fourth 80 MHz bandwidth. In three, you can have a PAPR of 6.69. For example, the 2x996 RU 2270 may have a PAPR of 6.72 in the RU set for the first 160 MHz bandwidth and 6.99 in the RU set for the second 160 MHz bandwidth. For example, a 4x996 RU 2280 may have a PAPR of 6.69.

The PAPR value of the LTF sequence of Equation 6 is smaller than the median PAPR value of the data based on FIG. 21 and Table 5. Since the LTF sequence of Equation 6 has a lower PAPR than the median PAPR of the data even considering RUs of all sizes, it can be considered that the LTF sequence has reasonable PAPR characteristics in RUs of all sizes.

A 1x EHT-LTF sequence for a 320 MHz bandwidth to support IEEE802.11be may be defined as in Equation 16.

Referring to Equation 16, the 1x EHT-LTF sequence _{may be configured based on a low 160MHz 1x LTF sequence (LTF 160MHz_lower_1x} ), a high 160MHz 1x LTF sequence (LTF _{160MHz _upper_1x} ), and a zero sequence. For example, 1x EHT-LTF sequence may be mapped from tone index -2036 to tone index 2036. The zero sequence zeroes(1, 23) may be a sequence in which zeros are mapped to 23 consecutive tones.

The low 160MHz 1x LTF sequence may be configured based on a low 80MHz 1x LTF sequence (LTF _{80MHz _lower_1x} ), a high 80MHz 1x LTF sequence (LTF _{80MHz _upper_1x} ), and a zero sequence. The high 160MHz 1x LTF sequence may be constructed based on the low 80MHz 1x LTF sequence, the high 80MHz 1x LTF sequence, and the zero sequence. The low 80 MHz 1x LTF sequence and the high 80 MHz 1x LTF sequence may be sequences defined in IEEE802.11ax.

The low 80MHz 1x LTF sequence and the high 80MHz 1x LTF sequence may be sequences based on Equations 17 to 20.

On the other hand, the sequence shown in Equation 16 may have a relatively high peak to average power ratio (PAPR) due to the repetition characteristic. Therefore, in order to lower the PAPR, as shown in Equation 21, a phase rotation may be performed on a specific sequence set among the EHT-LTF sequences.

The EHT-LTF sequence of Equation 21 has a PAPR of 4.92 dB. The EHT-LTF sequence of Equation 21 is a sequence in which the phase of the high 80MHz 1x LTF sequence (LTF _{80MHz_upper_1x ) of the high 160MHz 1x LTF sequence (LTF 160MHz_upper_1x) in the EHT-LTF sequence of Equation 16 is rotated.}

1x LTF may not be used in the MU PPDU. Therefore, 1x LTF may be transmitted only through 4x996 RUs in the case of transmission for a 320 MHz bandwidth. Therefore, performance may be determined by PAPR for the entire bandwidth (eg, 4x996 RUs) rather than PAPR for all types of RUs. The 1x LTF sequence of Equation 21 has a PAPR of 4.92 dB in a 320 MHz (eg, 4x996 RU) bandwidth.

Unlike the 4x LTF and 2x LTF sequences, 1x LTF is phase rotated on the high 80MHz 1x LTF sequence (LTF _{80MHz_upper_1x} ) rather than the low 80MHz 1x LTF sequence (LTF _{80MHz_lower_1x ) of the high 160MHz 1x LTF sequence (LTF 160MHz_upper_1x ).} can be 1x LTF is a high 160MHz 1x LTF sequences high 80MHz 1x LTF sequences (LTF _{80MHz_upper_1x)} of low 80MHz 1x LTF sequences (LTF _{80MHz_lower_1x)} high 160MHz 1x LTF sequences (LTF _{160MHz_upper_1x)} than the one that performs phase rotation on the (LTF _{160MHz_upper_1x)} A PAPR gain of about 0.6 dB can be obtained by performing the phase rotation.

Since 1x LTF has a relatively low PAPR, in order to have the same structure as 4x LTF and 2x LTF even if there is a loss in PAPR, a low 80MHz 1x LTF sequence (LTF _{80MHz_lower_1x} ) of a _{high 160MHz 1x LTF sequence (LTF 160MHz_upper_1x ) as shown in Equation 22} It is also possible to perform phase rotation on

The PAPR of the 1x LTF sequence in Equation 22 is 5.49 dB.

23 is a flowchart illustrating an embodiment of an operation of a transmitting STA.

Referring to FIG. 23 , a transmitting STA (station) may generate a long training field (LTF) signal (S2310). The LTF signal may be generated based on the LTF sequence for the 320 MHz band. The LTF sequence may be defined as a preset A sequence, a B sequence, and a zero sequence as follows.

{A, zero sequence, B, zero sequence, -A, zero sequence, B}

For example, the LTF sequence may be defined by Equation 6, 15, 21, or 22. The zero sequence zeros(1,23) may be a sequence in which zeros are mapped to 23 consecutive tones. The A sequence and the B sequence may be an LTF sequence for an 80 MHz band. The LTF sequence may be mapped from a lowest tone having a tone index of -2036 to a highest tone having a tone index of 2036. The A sequence and the B sequence may each consist of 1001 tones.

The transmitting STA may transmit a PHY protocol data unit (PPDU) including the LTF signal through a 320 MHz band (S2320).

24 is a flowchart illustrating an embodiment of an operation of a receiving STA.

Referring to FIG. 24 , a receiving station (STA) may receive a PHY protocol data unit (PPDU) including a long training field (LTF) signal through a 320 MHz band (S2410).

The LTF signal is generated based on the LTF sequence for the 320MHz band,

The LTF sequence may be defined as a preset A sequence, a B sequence, and a zero sequence as follows.

{A, zero sequence, B, zero sequence, -A, zero sequence, B}

For example, the LTF sequence may be defined by Equation 6, 15, 21, or 22. The zero sequence zeros(1,23) may be a sequence in which zeros are mapped to 23 consecutive tones. The A sequence and the B sequence may be an LTF sequence for an 80 MHz band. The LTF sequence may be mapped from a lowest tone having a tone index of -2036 to a highest tone having a tone index of 2036. The A sequence and the B sequence may each consist of 1001 tones.

The receiving STA may decode the PPDU (S2420). The receiving STA may estimate the channel based on the LTF signal included in the PPDU.

Some of the detailed steps shown in the example of FIGS. 23 and 24 may be omitted, and other steps may be added. The order of the steps shown in FIGS. 23 and 24 may vary.

The technical features of the present specification described above may be applied to various devices and methods. For example, the above-described technical features of the present specification 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 are 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 , or , may be implemented based on the processor 610 and the memory 620 of FIG. 19 . For example, an apparatus herein includes a memory and a processor operatively coupled with the memory, wherein the processor generates a long training field (LTF) signal, wherein the LTF signal is for a 320 MHz band. It is generated based on the LTF sequence, and the LTF sequence is defined as {A, zero sequence, B, zero sequence, -A, zero sequence, B} as a preset A sequence, B sequence, and zero sequence, In addition, it may be configured to transmit a PHY protocol data unit (PPDU) including the LTF signal through the 320 MHz band.

The technical features of the present specification may be implemented based on a CRM (computer readable medium). For example, CRM proposed by the present specification includes at least an instruction based on being executed by at least one processor of a STA (station) of a wireless local area network (WLAN) system. In one computer readable medium, a long training field (LTF) signal is generated, wherein the LTF signal is generated based on an LTF sequence for a 320 MHz band, and the LTF sequence is a preset A PHY protocol data unit (PHY protocol data unit) including a step and the LTF signal, defined as {A, zero sequence, B, zero sequence, -A, zero sequence, B} as an A sequence, a B sequence, and a zero sequence ) may store instructions for performing an operation including transmitting the 320 MHz band. The instructions stored in the CRM of the present specification may be executed by at least one processor. At least one processor related to CRM in 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 are applicable to various applications or business models. For example, the above-described technical features may be applied for wireless communication in a device supporting artificial intelligence (AI).

Artificial intelligence refers to a field that studies artificial intelligence or a methodology that can create it, and machine learning refers to a field that defines various problems dealt with in the field of artificial intelligence and studies methodologies to solve them. do. Machine learning is also defined as an algorithm that improves the performance of a certain task through constant experience.

An artificial neural network (ANN) is a model used in machine learning, and may refer to an overall model having problem-solving ability, which is composed of artificial neurons (nodes) that form a network by combining synapses. An artificial neural network may be defined by a connection pattern between neurons of different layers, a learning process that updates model parameters, and an activation function that generates 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 the artificial neural network, each neuron may output a function value of an activation function for input signals, weights, and biases input through synapses.

Model parameters refer to parameters determined through learning, and include the weight of synaptic connections and the bias of neurons. In addition, the hyperparameter refers to a parameter to be set before learning in a machine learning algorithm, and includes a learning rate, the number of iterations, a mini-batch size, an initialization function, and the like.

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

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

Supervised learning refers to a method of training an artificial neural network in a state where a label for the training data is given, and the label is the correct answer (or result value) that the artificial neural network should infer when the training data is input to the artificial neural network. can mean Unsupervised learning may refer to a method of training an artificial neural network in a state where no labels are given for training data. Reinforcement learning can refer to a learning method in which an agent defined in an environment learns to select an action or sequence of actions 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 also called deep learning, and deep learning is a part of machine learning. Hereinafter, machine learning is used in a sense including deep learning.

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

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

Robots can be classified into industrial, medical, home, 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 the robot joints. In addition, the movable robot includes a wheel, a brake, a propeller, and the like in the 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 is a generic term for virtual reality (VR), augmented reality (AR), and mixed reality (MR). VR technology provides only CG images of objects or backgrounds in the real world, AR technology provides virtual CG images on top of images of real objects, and MR technology is a computer that mixes and combines virtual objects in the real world. graphic technology.

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

XR technology can be applied to HMD (Head-Mount Display), HUD (Head-Up Display), mobile phone, tablet PC, laptop, desktop, TV, digital signage, etc. can be called

The claims described herein may be combined in various ways. For example, the technical features of the method claims of the present specification may be combined and implemented as an apparatus, and the technical features of the apparatus claims of the present specification may be combined and implemented as a method. In addition, the technical features of the method claim of the present specification and the technical features of the apparatus claim may be combined to be implemented as an apparatus, and the technical features of the method claim of the present specification and the technical features of the apparatus claim may be combined and implemented as a method.

Claims (14)

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

   STA (station) generates a long training field (LTF) signal,

   The LTF signal is generated based on the LTF sequence for the 320 MHz band,

   The LTF sequence is defined as follows as a preset A sequence, a B sequence, and a zero sequence; and

   {A, zero sequence, B, zero sequence, -A, zero sequence, B}

   Including, by the STA, transmitting a PHY protocol data unit (PPDU) including the LTF signal through the 320 MHz band,

   Way.
2. The method according to claim 1,

   The zero sequence is a sequence in which 0 is mapped to 23 consecutive tones,

   Way.
3. The method according to claim 1,

   The A sequence and the B sequence are LTF sequences for the 80 MHz band,

   Way.
4. The method according to claim 1,

   The LTF sequence is mapped from the lowest tone having a tone index -2036 to the highest tone having a tone index 2036,

   Way.
5. The method according to claim 1,

   The A sequence and the B sequence each consist of 1001 tones,

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

   a transceiver for transmitting and receiving a radio signal; and

   A processor coupled to the transceiver, the processor comprising:

   Generate a long training field (LTF) signal,

   The LTF signal is generated based on the LTF sequence for the 320 MHz band,

   The LTF sequence is defined as follows as a preset A sequence, a B sequence, and a zero sequence; And

   {A, zero sequence, B, zero sequence, -A, zero sequence, B}

   configured to transmit a PHY protocol data unit (PPDU) including the LTF signal through the 320 MHz band,

   STA.
7. 7. The method of claim 6,

   The zero sequence is a sequence in which 0 is mapped to 23 consecutive tones,

   STA.
8. 7. The method of claim 6,

   The A sequence and the B sequence are LTF sequences for the 80 MHz band,

   STA.
9. 7. The method of claim 6,

   The LTF sequence is mapped from the lowest tone having a tone index -2036 to the highest tone having a tone index 2036,

   STA.
10. 7. The method of claim 6,

    The A sequence and the B sequence each consist of 1001 tones,

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

    STA (station) receives a PPDU (PHY protocol data unit) including a long training field (LTF) signal through a 320 MHz band,

    The LTF signal is generated based on the LTF sequence for the 320MHz band,

    The LTF sequence is defined as follows as a preset A sequence, a B sequence, and a zero sequence; and

    {A, zero sequence, B, zero sequence, -A, zero sequence, B}

    Including, by the STA, decoding the PPDU,

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

    a transceiver for transmitting and receiving a radio signal; and

    A processor coupled to the transceiver, the processor comprising:

    Receive a PPDU (PHY protocol data unit) including a long training field (LTF) signal through a 320 MHz band,

    The LTF signal is generated based on the LTF sequence for the 320MHz band,

    The LTF sequence is defined as follows as a preset A sequence, a B sequence, and a zero sequence; And

    {A, zero sequence, B, zero sequence, -A, zero sequence, B}

    configured to decode the PPDU,

    STA.
13. At least one computer readable medium including instructions based on being executed by at least one processor of a STA (station) of a Wireless Local Area Network (WLAN) system ) in

    Generate a long training field (LTF) signal,

    The LTF signal is generated based on the LTF sequence for the 320 MHz band,

    The LTF sequence is defined as follows as a preset A sequence, a B sequence, and a zero sequence; and

    {A, zero sequence, B, zero sequence, -A, zero sequence, B}

    Performing an operation comprising the step of transmitting a PPDU (PHY protocol data unit) including the LTF signal through the 320 MHz band,

    Device.
14. A device on a wireless local area network (WLAN) system, comprising:

    Memory; and

    a processor operatively coupled with the memory, the processor comprising:

    Generate a long training field (LTF) signal,

    The LTF signal is generated based on the LTF sequence for the 320 MHz band,

    The LTF sequence is defined as follows as a preset A sequence, a B sequence, and a zero sequence; And

    {A, zero sequence, B, zero sequence, -A, zero sequence, B}

    configured to transmit a PHY protocol data unit (PPDU) including the LTF signal through the 320 MHz band,

    Device.

Images