Transmission or reception method and apparatus based on distributed resource unit tone plan in wireless LAN system

Abstract

Disclosed are a transmission or reception method and apparatus based on a distributed resource unit tone plan in a wireless LAN system. According to one embodiment of the present disclosure, a method performed by a first station (STA) in a wireless local area network (WLAN) system may comprise the steps of: generating a PPDU including one or more fields, the one or more fields being mapped onto one or more DRUs; and transmitting the PPDU to one or more second STAs on a bandwidth including the first 20 MHz channel and the second 20 MHz channel. Available subcarriers in the first 20 MHz channel and the second 20 MHz channel may be subcarriers excluding 5 DC subcarriers, 16 null subcarriers, 23 guard subcarriers, and 36 pilot subcarriers among 512 subcarriers in a 40 MHz channel including the first 20 MHz channel and the second 20 MHz channel.

Description

TECHNICAL FIELD

[0001] The disclosure relates to a transmission or reception method and apparatus based on a distributed resource unit tone plan in a wireless local area network (WLAN) system. BACKGROUND

[0002] New technologies for improving transmission rates, increasing bandwidth, improving reliability, reducing errors, and reducing latency have been introduced for wireless LANs (WLANs). Among the WLAN technologies, the Institute of Electrical and Electronics Engineers (IEEE) 802.11 series standards can be referred to as Wi-Fi. For example, recently introduced technologies for WLANs include very high throughput (VHT) enhancements of the 802.11ac standard and high efficiency (HE) enhancements of the IEEE 802.11ax standard.

[0003] In order to provide a more advanced wireless communication environment, improved technologies for extremely high throughput (EHT) are being discussed. For example, technologies for MIMO and multi-access point (AP) coordination that support increased bandwidth, efficient use of multiple frequency bands, and increased spatial streams are being researched, and in particular, various technologies are being researched to support low latency or real-time traffic. In addition, new technologies are being discussed to support ultra-high reliability (UHR), including improvements or extensions of EHT technologies. SUMMARY

[0004] TECHNICAL PROBLEM

[0005] The technical problem of the disclosure is to provide a transmission or reception method and apparatus based on a distributed resource unit tone plan in a WLAN system.

[0006] The technical objects to be achieved by the disclosure are not limited to the aforementioned technical objects and other technical objects not described herein will be clearly understood from the following description by one of ordinary skill in the art.

[0007] TECHNICAL SOLUTION

[0008] A method performed by a first station (STA) in a wireless local area network (WLAN) system according to an aspect of the disclosure can include generating a physical layer protocol data unit (PPDU) including one or more fields mapped on one or more distributed resource units (DRUs), and transmitting the PPDU to one or more second STAs on a bandwidth including a first 20 MHz channel and a second 20 MHz channel. Based on the one or more DRUs including a 26-tone DRU, the 26-tone DRU can be one of 9 predefined 26-tone DRUs, an nth(n=1, 2,..., 9) 26-tone DRU can include an nth lowest subcarrier among available subcarriers, and can be defined as every 9th subcarrier based on the nth lowest subcarrier, respectively for the first 20 MHz channel and the second 20 MHz channel. Here, the available subcarriers in the first 20 MHz channel and the available subcarriers in the second 20 MHz channel can be subcarriers excluding 5 direct current (DC) subcarriers, 16 null subcarriers, 23 guard subcarriers, and 36 pilot subcarriers among 512 subcarriers within a 40 MHz channel including the first 20 MHz channel and the second 20 MHz channel.

[0009] A method performed by a second station (STA) in a wireless local area network (WLAN) system according to an additional aspect of the disclosure can include receiving a physical layer protocol data unit (PPDU) including one or more fields from a first STA on a bandwidth including a first 20 MHz channel and a second 20 MHz channel, and decoding the one or more fields mapped on one or more distributed resource units (DRUs). Based on the one or more DRUs including a 26-tone DRU, the 26-tone DRU can be one of 9 predefined 26-tone DRUs, an nth(n=1, 2,..., 9) 26-tone DRU can include an nth lowest subcarrier among available subcarriers, and can be defined as every 9th subcarrier based on the nth lowest subcarrier, respectively for the first 20 MHz channel and the second 20 MHz channel. Here, the available subcarriers in the first 20 MHz channel and the available subcarriers in the second 20 MHz channel can be subcarriers excluding 5 direct current (DC) subcarriers, 16 null subcarriers, 23 guard subcarriers, and 36 pilot subcarriers among 512 subcarriers within a 40 MHz channel including the first 20 MHz channel and the second 20 MHz channel.

[0010] Technical effects

[0011] According to the disclosure, a transmission or reception method and apparatus based on a distributed resource unit tone plan in a WLAN system can be provided.

[0012] Effects achievable by the present disclosure are not limited to the above-mentioned effects, and other effects not described herein can be clearly understood by those skilled in the relevant art from the following description. BRIEF DESCRIPTION OF DRAWINGS

[0013] The accompanying drawings, included as part of the specific embodiments for understanding the present disclosure, provide embodiments of the present disclosure and describe technical features of the present disclosure together with the specific embodiments.

[0014] Figure 1 A configuration block diagram of a wireless communication device according to an embodiment of the present disclosure is illustrated.

[0015] Figure 2 is a diagram illustrating an exemplary structure of a WLAN system to which the present disclosure can be applied.

[0016] Figure 3 is a diagram for explaining a link setup process to which the present disclosure can be applied.

[0017] Figure 4 is a diagram for explaining a backoff process to which the present disclosure can be applied.

[0018] Figure 5 is a diagram for explaining a CSMA / CA-based frame transmission operation to which the present disclosure can be applied.

[0019] Figure 6 is a diagram for explaining an example of a frame structure used in a WLAN system to which the present disclosure can be applied.

[0020] Figure 7 is a diagram illustrating an example of a PPDU defined in an IEEE 802.11 standard to which the present disclosure can be applied.

[0021] Figures 8 to 10 is a diagram for explaining an example of a resource unit of a WLAN system to which the present disclosure can be applied.

[0022] Figure 11 is a diagram for explaining an example of a DRU to which the present disclosure can be applied.

[0023] Figure 12 is a diagram representing an exemplary format of a trigger frame to which the present disclosure can be applied.

[0024] Figure 13 is a diagram for explaining an example of a DRU tone plan-based PPDU reception method of a first STA according to the present disclosure.

[0025] Figure 14 is a diagram for explaining an example of a DRU tone plan-based PPDU transmission method of a second STA according to the present disclosure.

[0026] Figure 15 is a diagram for explaining a PPDU transmission and reception procedure between a transmitting STA and a receiving STA according to an example of the disclosure. DETAILED DESCRIPTION

[0027] Hereinafter, embodiments according to the disclosure will be described in detail with reference to the accompanying drawings. The detailed description disclosed by the accompanying drawings is to describe exemplary embodiments of the disclosure and is not intended to represent the only embodiment in which the disclosure can be implemented. The following detailed description includes specific details to provide a complete understanding of the disclosure. However, those skilled in the relevant art will know that the disclosure can be implemented without the specific details.

[0028] In some cases, known structures and devices can be omitted, or can be shown in the form of a block diagram based on a core function of each structure and device in order to facilitate the prevention of obscuring the concept of the disclosure.

[0029] In the disclosure, when an element is referred to as being "connected", "combined", or "linked" to another element, it can include an indirect connection relationship between the other element and a further element existing therebetween as well as a direct connection relationship. In addition, in the disclosure, the term "including" or "having" specifies the existence of the mentioned features, steps, operations, components, and / or elements, but does not exclude the existence or addition of one or more other features, stages, operations, components, elements, and / or groups thereof.

[0030] In the disclosure, terms such as "first", "second", and the like are used only to distinguish one element from another element and are not used to limit the elements, unless otherwise specified, and do not limit the order or importance between the elements, etc. Therefore, within the scope of the disclosure, a first element in an embodiment can be referred to as a second element in another embodiment, and likewise, a second element in an embodiment can be referred to as a first element in another embodiment.

[0031] The terms used in the disclosure are intended to describe the specific embodiments, not to limit the claims. As used in the description of the embodiments and the appended claims, the singular form is intended to include the plural form, unless the context clearly dictates otherwise. The term "and / or" used in the disclosure can refer to one of the relevant listed items, or mean that it refers to and includes any and all possible combinations of two or more of them. In addition, unless otherwise specified, " / " and "and / or" between words in the disclosure have the same meaning.

[0032] Examples of the present disclosure can be applied to various wireless communication systems. For example, examples of the present disclosure can be applied to a wireless LAN system. For example, examples of the present disclosure can be applied to a wireless LAN based on IEEE 802.11a / g / n / ac / ax standards. Further, examples of the present disclosure can be applied to a wireless LAN based on a newly proposed IEEE 802.11be (or EHT) standard. Examples of the present disclosure can be applied to a wireless LAN based on an IEEE 802.11be version 2 standard corresponding to additional enhancement technologies of the IEEE 802.11be version 1 standard. In addition, examples of the present disclosure can be applied to a wireless LAN based on a next-generation standard after the IEEE 802.11be. Further, examples of the present disclosure can be applied to a cellular wireless communication system. For example, it can be applied to a long term evolution (LTE) based technology based on a third generation partnership project (3GPP) standard and a cellular wireless communication system based on a 5G new radio (NR) technology.

[0033] Hereinafter, technical features to which examples of the present disclosure can be applied will be described.

[0034] Figure 1 A block diagram of a wireless communication device according to an embodiment of the present disclosure is exemplified.

[0035] Figure 1 The first device 100 and the second device 200 exemplified in the middle can be replaced with various terms such as a terminal, a wireless device, a wireless transmit / receive unit (WTRU), a user equipment (UE), a mobile station (MS), a user terminal (UT), a mobile subscriber station (MSS), a mobile subscriber unit (MSU), a subscriber station (SS), an advanced mobile station (AMS), a wireless terminal (WT), or simply a user, etc. In addition, the first device 100 and the second device 200 include an access point (AP), a base station (BS), a fixed station, a node B, a base transceiver system (BTS), a network. It can be replaced with various terms such as an artificial intelligence (AI) system, a road side unit (RSU), a repeater, a router, a relay, and a gateway.

[0036] Figure 1 The devices 100 and 200 exemplified in the middle can be referred to as a station (STA). For example, Figure 1The apparatuses 100 and 200 exemplified can be referred to with various terms such as a transmitting apparatus, a receiving apparatus, a transmitting STA, and a receiving STA. For example, the STAs 100 and 200 can perform an access point (AP) role or a non-AP role. That is, in the present disclosure, the STAs 100 and 200 can perform the functions of an AP and / or a non-AP. When the STAs 100 and 200 perform the AP function, they can be simply referred to as an AP, and when the STAs 100 and 200 perform the non-AP function, they can be simply referred to as a STA. In addition, in the present disclosure, an AP can also be indicated as an AP STA.

[0037] Referring to Figure 1 The first apparatus 100 and the second apparatus 200 can transmit and receive radio signals through various wireless LAN technologies (for example, IEEE 802.11 series). The first apparatus 100 and the second apparatus 200 can include an interface for a medium access control (MAC) layer and a physical layer (PHY) to comply with the IEEE 802.11 standard.

[0038] In addition, the first apparatus 100 and the second apparatus 200 can additionally support various communication standard (for example, 3GPP LTE series, 5G NR series standards, etc.) technologies in addition to the wireless LAN technology. In addition, the apparatuses of the present disclosure can be implemented in various apparatuses such as a mobile phone, a vehicle, a personal computer, an augmented reality (AR) apparatus, and a virtual reality (VR) apparatus, etc. In addition, the STAs of the present specification can support various communication services such as a voice call, a video call, data communication, autonomous driving, machine type communication (MTC), machine-to-machine (M2M), device-to-device (D2D), IoT (Internet of Things), etc.

[0039] The first apparatus 100 can include one or more processors 102 and one or more memories 104, and can additionally include one or more transceivers 106 and / or one or more antennas 108. The processor 102 can control the memory 104 and / or the transceiver 106, and can be configured to implement descriptions, functions, procedures, suggestions, methods and / or operational flowcharts included in the present disclosure. For example, the processor 102 can generate first information / signal by processing information in the memory 104, and then transmit a wireless signal including the first information / signal through the transceiver 106. Also, the processor 102 can receive a wireless signal including second information / signal through the transceiver 106, and then store information obtained by processing a signal of the second information / signal in the memory 104. The memory 104 can be connected to the processor 102 and can store a variety of information related to operations of the processor 102. For example, the memory 104 can store software code including instructions for performing all or a part of processes controlled by the processor 102 or for performing descriptions, functions, procedures, suggestions, methods and / or operational flowcharts included in the present disclosure. Here, the processor 102 and the memory 104 can be a part of a communication modem / circuit / chip designed to implement a wireless LAN technology (e.g., IEEE 802.11 series). The transceiver 106 can be connected to the processor 102 and can transmit and / or receive a wireless signal through the one or more antennas 108. The transceiver 106 can include a transmitter and / or a receiver. The transceiver 106 can be used together with an RF (Radio Frequency) unit. In the present disclosure, a wireless device can mean a communication modem / circuit / chip.

[0040] The second apparatus 200 can include one or more processors 202 and one or more memories 204, and can additionally include one or more transceivers 206 and / or one or more antennas 208. The processor 202 can control the memory 204 and / or the transceiver 206, and can be configured to implement descriptions, functions, procedures, suggestions, methods and / or operational flowcharts included in the present disclosure. For example, the processor 202 can generate third information / signal by processing information in the memory 204, and then transmit a wireless signal including the third information / signal through the transceiver 206. Also, the processor 202 can receive a wireless signal including fourth information / signal through the transceiver 206, and then store information obtained by signal processing of the fourth information / signal in the memory 204. The memory 204 can be connected to the processor 202 and can store a variety of information related to operations of the processor 202. For example, the memory 204 can store software code including instructions for performing all or part of processes controlled by the processor 202 or for performing descriptions, functions, procedures, suggestions, methods and / or operational flowcharts included in the present disclosure. Here, the processor 202 and the memory 204 can be part of a communication modem / circuit / chip designed to implement a wireless LAN technology (e.g., IEEE 802.11 series). The transceiver 206 can be connected to the processor 202 and can transmit and / or receive a wireless signal through the one or more antennas 208. The transceiver 206 can include a transmitter and / or a receiver. The transceiver 206 can be used together with an RF unit. In the present disclosure, an apparatus can mean a communication modem / circuit / chip.

[0041] Hereinafter, the hardware elements of the apparatuses 100, 200 will be described in more detail. Without limitation, one or more protocol layers can be implemented by the one or more processors 102, 202. For example, the one or more processors 102, 202 can implement one or more layers (e.g., functional layers such as PHY, MAC). The one or more processors 102, 202 can generate one or more PDUs (Protocol Data Units) and / or one or more SDUs (Service Data Units) according to the descriptions, functions, procedures, suggestions, methods, and / or operational flowcharts disclosed in the present disclosure. The one or more processors 102, 202 can generate messages, control information, data, or information according to the descriptions, functions, procedures, suggestions, methods, and / or operational flowcharts disclosed in the present disclosure. The one or more processors 102, 202 can generate signals (e.g., baseband signals) including the PDUs, SDUs, messages, control information, data, or information according to the functions, procedures, suggestions, and / or methods disclosed in the present disclosure to provide the same to the one or more transceivers 106, 206. The one or more processors 102, 202 can receive signals (e.g., baseband signals) from the one or more transceivers 106, 206 according to the descriptions, functions, procedures, suggestions, methods, and / or operational flowcharts included in the present disclosure, and obtain the PDUs, SDUs, messages, control information, data, or information.

[0042] The one or more processors 102, 202 can be referred to as controllers, microcontrollers, microprocessors, or microcomputers. The one or more processors 102, 202 can be implemented by hardware, firmware, software, or a combination thereof. For example, one or more ASICs (Application Specific Integrated Circuits), one or more DSPs (Digital Signal Processors), one or more DSPDs (Digital Signal Processors Devices), one or more PLDs (Programmable Logic Devices), or one or more FPGAs (Field Programmable Gate Arrays) can be included in the one or more processors 102, 202. The descriptions, functions, procedures, suggestions, methods, and / or operational flowcharts included in the present disclosure can be implemented by using firmware or software, and the firmware or software can be implemented as including modules, procedures, functions, etc. The firmware or software configured to perform the descriptions, functions, procedures, suggestions, methods, and / or operational flowcharts included in the present disclosure can be included in the one or more processors 102, 202, or can be stored in the one or more memories 104, 204 and driven by the one or more processors 102, 202. The descriptions, functions, procedures, suggestions, methods, and / or operational flowcharts included in the present disclosure can be implemented by using firmware or software in the form of codes, instructions, and / or instruction sets.

[0043] One or more memories 104, 204 can be connected to one or more processors 102, 202 and can store data, signals, messages, information, programs, codes, instructions, and / or commands in various forms. One or more memories 104, 204 can be configured with ROM, RAM, EPROM, flash memory, hard drives, registers, cache memories, computer-readable storage media, and / or combinations thereof. One or more memories 104, 204 can be located internal and / or external to one or more processors 102, 202. In addition, one or more memories 104, 204 can be connected to one or more processors 102, 202 by various technologies such as wired or wireless connections.

[0044] The one or more transceivers 106, 206 can transmit user data, control information, wireless signals / channels, etc. mentioned in the methods and / or operational flowcharts, etc. of the disclosure to one or more other apparatuses. The one or more transceivers 106, 206 can receive user data, control information, wireless signals / channels, etc. mentioned in the descriptions, functions, processes, suggestions, methods and / or operational flowcharts, etc. included in the disclosure from one or more other apparatuses. For example, the one or more transceivers 106, 206 can be connected to the one or more processors 102, 202 and can transmit and receive wireless signals. For example, the one or more processors 102, 202 can control the one or more transceivers 106, 206 to transmit user data, control information, or wireless signals to one or more other apparatuses. In addition, the one or more processors 102, 202 can control the one or more transceivers 106, 206 to receive user data, control information, or wireless signals from one or more other apparatuses. In addition, the one or more transceivers 106, 206 can be connected to the one or more antennas 108, 208, and the one or more transceivers 106, 206 can be configured to transmit and receive user data, control information, wireless signals / channels, etc. mentioned in the descriptions, functions, processes, suggestions, methods and / or operational flowcharts, etc. included in the disclosure through the one or more antennas 108, 208. In the disclosure, the one or more antennas can be a plurality of physical antennas or a plurality of logical antennas (for example, antenna ports). The one or more transceivers 106, 206 can convert received wireless signals / channels, etc. from RF band signals to baseband signals to process received user data, control information, wireless signals / channels, etc. by using the one or more processors 102, 202. The one or more transceivers 106, 206 can convert user data, control information, wireless signals / channels, etc. processed by using the one or more processors 102, 202 from baseband signals to RF band signals. Accordingly, the one or more transceivers 106, 206 can include (analog) oscillators and / or filters.

[0045] For example, one of the STAs 100 and 200 can perform the intended operation of an AP, and the other of the STAs 100 and 200 can perform the intended operation of a non-AP STA. For example, Figure 1 The transceivers 106 and 206 of the STA 100 and 200 can perform transmission and reception operations of signals (for example, packets or physical layer protocol data units (PPDUs) conforming to IEEE 802.11a / b / g / n / ac / ax / be / bn). In addition, in the disclosure, operations in which various STAs generate transmission / reception signals or perform data processing or calculation in advance for transmission / reception signals can be performed by the one or more processors 102, 202. Figure 1The operations of generating a transmission / reception signal or performing data processing or calculation in advance for the operations of the transmission / reception signal can include, for example, 1) determining / acquiring / configuring / calculating / decoding / encoding bit information of a field (a signal (SIG), a short training field (STF), a long training field (LTF), data, etc.) included in a PPDU; 2) determining / configuring / acquiring a time resource or a frequency resource (e.g., a subcarrier resource) for a field (SIG, STF, LTF, data, etc.) included in a PPDU; 3) determining / configuring / acquiring a specific sequence (e.g., a pilot sequence, an STF / LTF sequence, an additional sequence applied to SIG) for a field (SIG, STF, LTF, data, etc.) included in a PPDU action; 4) a power control operation and / or a power saving operation applied to a STA; 5) an operation related to ACK signal determination / acquisition / configuration / calculation / decoding / encoding, etc. In addition, in the following examples, various information (e.g., information related to a field / subfield / control field / parameter / power, etc.) used by various STAs to determine / acquire / configure / calculate / decode / encode a transmission signal and a reception signal can be stored in the memories 104 and 204 of the processors 102 and 202. Figure 1

[0046] Hereinafter, a downlink (DL) can mean a link for communication from an AP STA to a non-AP STA, and a DL PPDU / packet / signal can be transmitted and received through the DL. In the DL communication, a transmitter can be a part of the AP STA, and a receiver can be a part of the non-AP STA. An uplink (UL) can mean a link for communication from a non-AP STA to an AP STA, and a UL PPDU / packet / signal can be transmitted and received through the UL. In the UL communication, a transmitter can be a part of the non-AP STA, and a receiver can be a part of the AP STA.

[0047] Figure 2 is a diagram illustrating an exemplary structure of a wireless LAN system to which the present disclosure can be applied.

[0048] The structure of the wireless LAN system can be composed of a plurality of components. The wireless LAN supporting mobility of a STA transparent to an upper layer can be provided through the interaction of the plurality of components. A basic service set (BSS) corresponds to a basic building block of the wireless LAN. Figure 2 Exemplarily, it is shown that there are two BSSs (BSS1 and BSS2), and two STAs (STA1 and STA2 are included in BSS1, and STA3 and STA4 are included in BSS2) are included as members of each BSS. Figure 2 ​The ellipse representing the BSS can also be understood to represent a coverage area in which the STAs included in the corresponding BSS maintain communication. This area can be referred to as a basic service area (BSA). When a STA moves outside the BSA, it cannot directly communicate with other STAs within the BSA.

[0049] If the DS shown in Figure 2 The most basic BSS type in a wireless LAN is an independent BSS (IBSS) if the DS shown in FIG. 1 is not considered. For example, an IBSS can have a minimum form including only two STAs. For example, assuming that other components are omitted, a BSS 1 including only STA 1 and STA 2 or a BSS 2 including only STA 3 and STA 4 can correspond to representative examples of an IBSS, respectively. This configuration is possible when STAs can directly communicate without an AP. In addition, in this type of wireless LAN, it is not pre-configured, but can be configured when a LAN is needed, and this can be referred to as an ad-hoc network. Since the IBSS does not include an AP, there is no centralized management entity. That is, in the IBSS, STAs are managed in a distributed manner. In the IBSS, all STAs can consist of mobile STAs, and access to a distribution system (DS) is not allowed, thereby forming a self-contained network.

[0050] Membership of STAs in a BSS can be dynamically changed by turning on or off the STAs, entering or exiting the BSS area, etc. In order to become a member of a BSS, a STA can join the BSS using a synchronization process. In order to access all services of the BSS infrastructure, a STA should be associated with the BSS. The association can be dynamically established, and can include use of a distribution system service (DSS).

[0051] A direct STA-to-STA distance in a wireless LAN can be limited by PHY performance. In some cases, this distance limitation can be sufficient, but in some cases, communication between STAs at a longer distance can be required. A distribution system (DS) can be configured to support extended coverage.

[0052] The DS means a structure of interconnection of BSSs. Specifically, as Figure 2As shown, the BSS can exist as an extended form of a network composed of a plurality of BSSs. The DS is a logical concept, and can be specified by the characteristics of a distributed system medium (DSM). In this regard, the wireless medium (WM) and the DSM can be logically separated. Each logical medium is used for a different purpose, and is used by a different component. These media are not limited to being the same, nor are they limited to being different. In this way, the flexibility of the wireless LAN structure (DS structure or other network structure) can be interpreted as the plurality of media being logically different. That is, the wireless LAN structure can be implemented in various ways, and the corresponding wireless LAN structure can be independently specified by the physical characteristics of each implementation.

[0053] The DS can support mobile devices by providing seamless integration of a plurality of BSSs and providing logical services necessary for addressing addresses leading to destinations. In addition, the DS can also include a component called a portal, which is used as a bridge for a connection between the wireless LAN and other networks (for example, IEEE 802.X).

[0054] The AP enables access to the DS through the WM for an associated non-AP STA, and means an entity that also has the function of a STA. Data movement between the BSS and the DS can be performed through the AP. For example, Figure 2 The STAs 2 and 3 shown in FIG. 1 have the function of a STA, and provide a function that allows an associated non-AP STA (STAs 1 and 4) to access the DS. In addition, since all APs basically correspond to STAs, all APs are addressable entities. The address used by the AP to communicate on the WM is not necessarily the same as the address used by the AP to communicate on the DSM. A BSS composed of an AP and one or more STAs can be referred to as an infrastructure BSS.

[0055] Data transmitted from one of the STAs associated with the AP to the STA address of the corresponding AP can always be received at an uncontrolled port, and can be processed by an IEEE 802.1X port access entity. In addition, when the controlled port is authenticated, the transmitted data (or frame) can be delivered to the DS.

[0056] In addition to the structure of the DS described above, an extended service set (ESS) can be configured to provide a wide coverage range.

[0057] The ESS means a network composed of DSs and BSSs with arbitrary size and complexity. The ESS can correspond to a set of BSSs connected to one DS. However, the ESS does not include the DS. The ESS network is characterized as IBSS in the logical link control (LLC) layer. STAs included in the ESS can communicate with each other, and a mobile STA can move from one BSS to another BSS (within the same ESS) transparently to the LLC. The APs included in one ESS can have the same service set identification (SSID). The SSID is distinguished from the BSSID which is an identifier of the BSS.

[0058] The wireless LAN system does not assume anything about the relative physical locations of BSSs, and all of the following forms are possible. The BSSs can partially overlap, which is a form commonly used to provide continuous coverage. In addition, the BSSs can not be physically connected, and logically, there is no limit to the distance between the BSSs. In addition, the BSSs can be physically located at the same place, which can be used to provide redundancy. In addition, one (or more than one) IBSS or ESS network can physically exist in the same space as one (or more than one) ESS network. This can correspond to a form of the ESS network when an ad hoc network operates in a place where an ESS network exists, when physically overlapping wireless networks are configured by different organizations, or when two or more different access and security policies are required in the same place, or the like.

[0059] Figure 3 is a diagram for explaining a link establishment process to which the present disclosure can be applied.

[0060] In order for a STA to establish a link with respect to a network and transmit / receive data, it first discovers the network, performs authentication, establishes association, and needs to perform an authentication process for security. The link establishment process can also be referred to as a session initiation process or a session establishment process. In addition, the discovery, authentication, association, and security establishment processes of the link establishment process can be collectively referred to as an association process.

[0061] In step S310, the STA can perform a network discovery operation. The network discovery operation can include a scanning operation of the STA. That is, in order for the STA to access a network, it needs to find a network that it can participate in. The STA should identify a compatible network before participating in a wireless network, and the process of identifying a network present in a specific area is referred to as scanning.

[0062] The scanning scheme includes active scanning and passive scanning. Figure 3A network discovery operation including an active scan process is exemplarily illustrated. In the active scan, the STA performing the scan transmits a probe request frame to discover what APs exist around it while moving the channel and waits for a response thereto. The responder transmits a probe response frame as a response to the probe request frame to the STA having transmitted the probe request frame. Here, the responder can be the STA which last transmitted a beacon frame in the BSS of the channel being scanned. In the BSS, since the AP transmits the beacon frame, the AP becomes the responder, and in the IBSS, the STAs in the IBSS rotate to transmit the beacon frame, so the responder is not constant. For example, the STA which transmits the probe request frame on channel 1 and receives the probe response frame on channel 1 can store the BSS-related information included in the received probe response frame, and can move to the next channel (e.g., channel 2) and perform the scan in the same manner (i.e., transmission and reception of the probe request / response on channel 2).

[0063] Although not shown in Figure 3 , a scan operation can be performed in a passive scan manner. In the passive scan, the STA performing the scan waits for a beacon frame while moving the channel. The beacon frame is one of the management frames defined in IEEE 802.11, and is periodically transmitted to notify of the existence of a wireless network, and to allow the STA performing the scan to find the wireless network and participate in the wireless network. In the BSS, the AP is used to periodically transmit the beacon frame, and in the IBSS, the STAs within the IBSS rotate to transmit the beacon frame. When the STA performing the scan receives the beacon frame, the STA stores the information of the BSS included in the beacon frame, and records the beacon frame information in each channel while moving to another channel. The STA receiving the beacon frame can store the BSS-related information included in the received beacon frame, move to the next channel, and perform the scan in the next channel in the same manner. Comparing the active scan with the passive scan, the active scan has an advantage in that it has less delay and less power consumption than the passive scan.

[0064] After the STA discovers the network, an authentication process can be performed at step S320. In order to clearly distinguish from a security establishment operation of step S340 which will be described later, the authentication process can be referred to as a first authentication process.

[0065] The authentication process includes 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. The authentication frame for the authentication request / response corresponds to a management frame.

[0066] 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, and the like. This corresponds to some examples of information that can be included in an authentication request / response frame, and can be replaced with other information, or additional information can also be included.

[0067] The STA can transmit an authentication request frame to the AP. The AP can determine whether to allow authentication of the corresponding STA based on information included in the received authentication request frame. The AP can provide the result of the authentication processing to the STA through an authentication response frame.

[0068] After the STA is successfully authenticated, association processing can be performed at step S330. The association processing includes the following processing: the STA transmits an association request frame to the AP, and in response, the AP transmits an association response frame to the STA.

[0069] For example, the association request frame can include information related to various capabilities, a beacon listen interval, a service set identifier (SSID), supported rates, supported channels, an RSN, a mobility domain, supported operating classes, a traffic indication map broadcast request (TIM broadcast request), interworking service capabilities, and the like. For example, the association response frame can include information related to various capabilities, a status code, an association ID (AID), supported rates, an enhanced distributed channel access (EDCA) parameter set, a received channel power indicator (RCPI), a received signal to noise indicator (RSNI), a mobility domain, a super interval (e.g., an association recovery time), an overlapping BSS scan parameter, a TIM broadcast response, a quality of service (QoS) map, and the like. This corresponds to some examples of information that can be included in an association request / response frame, and can be replaced with other information, or additional information can also be included.

[0070] After the STA is successfully associated with the network, security establishment processing can be performed at step S340. The security establishment processing of step S340 can be referred to as an authentication processing through a robust security network association (RSNA) request / response, the authentication processing of step S320 is referred to as a first authentication processing, and the security establishment processing of step S340 can also be simply referred to as an authentication processing.

[0071] The security establishment processing of step S340 can include, for example, processing for establishing a private key through an extensible authentication protocol (EAPOL) frame over a LAN using a four-way handshake. In addition, the security establishment processing can be performed according to a security scheme that is not defined in the IEEE 802.11 standard.

[0072] Figure 4 is a diagram for explaining a backoff processing to which the present disclosure can be applied.

[0073] In a wireless LAN system, a basic access mechanism of a medium access control (MAC) is a carrier sense multiple access with collision avoidance (CSMA / CA) mechanism. The CSMA / CA mechanism is also called a distributed coordination function (DCF) of IEEE 802.11 MAC, and basically adopts a "listen before talk" access mechanism. According to this type of access mechanism, an AP and / or a STA can perform an explicit channel assessment (CCA) of sensing a wireless channel or medium during a predetermined time interval (e.g., a DCF interframe space (DIFS)) before starting transmission. As a result of sensing, if it is determined that the medium is in an idle state, a frame transmission is started by the corresponding medium. On the other hand, if it is detected that the medium is occupied or busy, the corresponding AP and / or STA does not start its own transmission, and can set a delay period (e.g., a random backoff period) for medium access and attempt frame transmission after waiting. By applying the random backoff period, since a plurality of STAs are expected to attempt frame transmission after waiting for different time periods, a collision can be minimized.

[0074] In addition, the IEEE 802.11 MAC protocol provides a hybrid coordination function (HCF). The HCF is based on the DCF and a point coordination function (PCF). The PCF is a synchronous access method based on polling, and refers to a method in which all receiving APs and / or STAs are periodically polled to receive data frames. In addition, the HCF has an enhanced distributed channel access (EDCA) and an HCF controlled channel access (HCCA). The EDCA is a contention-based access method that provides data frames to a plurality of users, and the HCCA uses a non-contention-based channel access method using a polling mechanism. In addition, the HCF includes a medium access mechanism for improving the QoS (quality of service) of a wireless LAN, and can transmit QoS data in both a contention period (CP) and a contention free period (CFP).

[0075] Referring to Figure 4 An operation based on a random backoff period will be described. When an occupied / busy medium becomes an idle state, a plurality of STAs can attempt to transmit data (or frames). As a method of minimizing collisions, each of the STAs can respectively select a random backoff count, and attempt transmission after waiting for a corresponding time slot. The random backoff count has a pseudo-random integer value, and can be determined as one of values ranging from 0 to CW. Here, the CW is a contention window parameter value. The CW parameter is given a CWmin as an initial value, but can take a value twice as large in the case of transmission failure (e.g., when an ACK for a transmitted frame is not received). When the CW parameter value reaches CWmax, data transmission can be attempted while maintaining the CWmax value until data transmission is successful, and when data transmission is successful, the CWmin value is reset. The values of CW, CWmin, and CWmax are preferably set to 2n -1 (n = 0, 1, 2,...).

[0076] When the random backoff process starts, the STA continuously monitors the medium during the backoff slot countdown according to the determined backoff count value. When monitoring the medium for occupation, it stops the countdown and waits, and when the medium becomes idle, it resumes the remaining part of the countdown.

[0077] In the example of Figure 4 , when a packet to be transmitted arrives at the MAC of STA 3, STA 3 can transmit the frame immediately after confirming that the medium is idle for DIFS. The remaining STAs monitor and wait for the medium to be occupied / busy. Meanwhile, data to be transmitted can also occur in each of STA 1, STA 2, and STA 5, and when the medium is monitored to be idle, each STA waits for DIFS and then can perform a countdown of the backoff slot according to the random backoff count value selected by each STA. It is assumed that STA 2 selects the smallest backoff count value and STA 1 selects the largest backoff count value. That is, a case is exemplified in which the remaining backoff time of STA 5 is shorter than that of STA 1 when STA 2 completes the backoff count and starts frame transmission. STA 1 and STA 5 temporarily stop the countdown and wait while STA 2 occupies the medium. When the occupation of STA 2 ends and the medium becomes idle again, STA 1 and STA 5 wait for DIFS and resume the stopped backoff count. That is, frame transmission can start after the remaining backoff slot is counted down for the remaining backoff time. Since the remaining backoff time of STA 5 is shorter than that of STA 1, STA 5 starts frame transmission. Data to be transmitted can also occur in STA 4 while STA 2 occupies the medium. From the perspective of STA 4, when the medium becomes idle, STA 4 can wait for DIFS and then can perform a countdown according to the random backoff count value selected by STA 4 and start transmitting a frame. Figure 4 The example of

[0078] As in the example of Figure 4In the example, data frames are frames used to send data forwarded to higher layers and can be sent after a backoff performed after DIFS, starting from when the medium becomes idle. Additionally, management frames are frames used to exchange management information that has not been forwarded to higher layers and are sent after a backoff performed after an IFS such as DIFS or Point Coordination Function IFS (PIFS). Subtypes of management frames include beacons, association requests / responses, reassociation requests / responses, probe requests / responses, authentication requests / responses, etc. Control frames are frames used to control access to the medium. Subtypes of control frames include request to send (RTS), clear send (CTS), acknowledge (ACK), power-saving polling (PS-Poll), block ACK (BlockAck), block ACK request (BlockACKReq), empty data packet announcement (NDP announcement), and triggers, etc. If a control frame is not a response frame to the previous frame, it is sent after a backoff performed after DIFS; if it is a response frame to the previous frame, it is sent without a backoff performed after short IFS (SIFS). The type and subtype of a frame can be identified by the type field and subtype field in the Frame Control (FC) field.

[0079] The Quality of Service (QoS) ST can perform a backoff following the Arbitration IFS (AIFS) for the Access Class (AC) to which the frame belongs (i.e., AIFS where i is a value determined by the AC) before the frame can be transmitted. Here, the frame that can use AIFS can be a data frame, management frame, or control frame, rather than a response frame.

[0080] Figure 5 This is a diagram illustrating the CSMA / CA-based frame transmission operation that can be applied to this disclosure.

[0081] As mentioned above, in addition to physical carrier sensing of the medium directly sensed by the STA, the CSMA / CA mechanism also includes virtual carrier sensing. Virtual carrier sensing aims to compensate for problems such as hidden node issues that may occur during medium access. For virtual carrier sensing, the STA's MAC can use the Network Allocation Vector (NAV). The NAV is a value that indicates to other STAs the remaining time until the medium is available for current use or for STAs authorized to use the medium. Therefore, a value set to NAV corresponds to the period during which the STA sending the frame plans to use the medium, and during the corresponding period, STAs receiving the NAV value are prohibited from accessing the medium. For example, the NAV can be configured based on the value of the "Duration" field in the frame's MAC header.

[0082] exist Figure 5 In the example, it is assumed that STA1 intends to send data to STA2, and STA3 is in a position that can eavesdrop on some or all of the frames sent and received between STA1 and STA2.

[0083] To reduce the likelihood of transmission collision of multiple STAs in CSMA / CA based frame transmission operation, a mechanism using RTS / CTS frames can be applied. In Figure 5 the example, when the transmission of STA1 is being performed, as a result of carrier sensing by STA3, it can be determined that the medium is idle. That is, STA1 can correspond to a hidden node with respect to STA3. Alternatively, in Figure 5 the example, it can be determined that the medium is idle as a result of carrier sensing by STA3 when the transmission of STA2 is being performed. That is, STA2 can correspond to a hidden node with respect to STA3. By exchanging RTS / CTS frames before performing data transmission and reception between STA1 and STA2, STAs outside the transmission range of one of STA1 or STA2 or STAs outside the carrier sensing range from the transmission of STA1 or STA3 can not attempt to occupy the channel during data transmission and reception between STA1 and STA2.

[0084] Specifically, STA1 can determine whether the channel is being used through carrier sensing. In terms of physical carrier sensing, STA1 can determine the channel occupancy idle state based on the energy level or signal correlation detected in the channel. In addition, in terms of virtual carrier sensing, STA1 can determine the channel occupancy state using a network allocation vector (NAV) timer.

[0085] When the channel is idle during DIFS, STA1 can transmit an RTS frame to STA2 after performing backoff. When STA2 receives the RTS frame, STA2 can transmit a CTS frame to STA1 as a response to the RTS frame after SIFS.

[0086] If the STA 3 cannot overhear the CTS frame from the STA 2 but can overhear the RTS frame from the STA 1, the STA 3 can set the NAV timer for the frame transmission period (e.g., SIFS + CTS frame + SIFS + data frame + SIFS + ACK frame) thereafter using the duration information included in the RTS frame. Alternatively, if the STA 3 can overhear the CTS frame from the STA 2, the STA 3 can set the NAV timer for the frame transmission period (e.g., SIFS + data frame + SIFS + ACK frame) thereafter using the duration information included in the CTS frame, although the STA 3 cannot overhear the RTS frame from the STA 1. That is, if the STA 3 can overhear one or more of the RTS frame or the CTS frame from one or more of the STA 1 or the STA 2, the STA 3 can set the NAV accordingly. When the STA 3 receives a new frame before the NAV timer expires, the STA 3 can update the NAV timer using the duration information included in the new frame. The STA 3 does not attempt channel access until the NAV timer expires.

[0087] When the STA 1 receives the CTS frame from the STA 2, the STA 1 can transmit a data frame to the STA 2 after SIFS from the time point of completion of reception of the CTS frame. When the STA 2 successfully receives the data frame, the STA 2 can transmit an ACK frame to the STA 1 after SIFS as a response to the data frame. When the NAV timer expires, the STA 3 can determine whether the channel is being used through carrier sensing. When the STA 3 determines that the channel is not being used by other terminals during DIFS after the NAV timer expires, the STA 3 can attempt channel access after a contention window (CW) according to random backoff has passed.

[0088] Figure 6 is a diagram for explaining an example of a frame structure used in a WLAN system to which the disclosure can be applied.

[0089] The PHY layer can prepare a MAC PDU (MPDU) to be transmitted by means of an instruction or primitive (meaning a set of instructions or parameters) from the MAC layer. For example, when a command requesting start of transmission of the PHY layer is received from the MAC layer, the PHY layer switches to a transmission mode, and configures information (e.g., data) provided from the MAC layer in the form of a frame and transmits it. In addition, when the PHY layer detects a valid preamble of a received frame, the PHY layer monitors a header of the preamble, and transmits a command informing the MAC layer of the start of reception of the PHY layer.

[0090] In this way, information transmission / reception in a wireless LAN system is performed in the form of a frame, and for this purpose, a PHY layer protocol data unit (PPDU) format is defined.

[0091] A basic PPDU can include a short training field (STF), a long training field (LTF), a signal (SIG) field, and a data (Data) field. The most basic PPDU format (e.g., non-HT (high throughput) as shown in FIG. 2A) can consist of only a legacy-STF (L-STF), a legacy-LTF (L-LTF), a legacy-SIG (L-SIG) field, and a data field. In addition, depending on the type of PPDU format (e.g., HT mixed format PPDU, HT greenfield format PPDU, VHT (very high throughput) PPDU, etc.), additional (or different types of) RL-SIG, U-SIG, non-legacy SIG field, non-legacy STF, non-legacy LTF (i.e., xx-SIG, xx-STF, xx-LTF (e.g., xx is HT, VHT, HE, EHT, etc.)) can be included between the L-SIG field and the data field. Figure 7

[0092] The STF is a signal for signal detection, automatic gain control (AGC), diversity selection, accurate time synchronization, etc., and the LTF is a signal for channel estimation and frequency error estimation. The STF and the LTF can be referred to as signals for synchronization and channel estimation of an OFDM physical layer.

[0093] The SIG field can include various information related to PPDU transmission and reception. For example, the L-SIG field consists of 24 bits, and the L-SIG field can include a 4-bit rate field, a 1-bit reserved bit, a 12-bit length field, a 1-bit parity check field, and a 6-bit tail field. The RATE field can include information about the modulation and coding rate of data. For example, the 12-bit length field can include information about the length or duration of the PPDU. For example, the value of the 12-bit length field can be determined based on the type of PPDU. For example, for non-HT, HT, VHT, or EHT PPDUs, the value of the length field can be determined as a multiple of 3. For example, for HE PPDUs, the value of the length field can be determined as a multiple of 3+1 or a multiple of 3+2.

[0094] The data field can include a SERVICE field, a physical layer service data unit (PSDU), and a PPDU tail bit, and, if necessary, a padding bit. Some bits of the SERVICE field can be used for synchronization of a descrambler at a receiving end. The PSDU corresponds to a MAC PDU defined in a MAC layer, and can include data generated / used in an upper layer. The PPDU tail bit can be used to return an encoder to a 0 state. The padding bit can be used to adjust the length of the data field by a predetermined unit.

[0095] ​The MAC PDU is defined according to various MAC frame formats, and a basic MAC frame consists of a MAC header, a frame body, and a frame check sequence (FCS). The MAC frame can consist of the MAC PDU and is transmitted / received through the PSDU of the data part of the PPDU format.

[0096] The MAC header includes a frame control field, a duration / ID field, an address field, etc. The frame control field can include control information required for frame transmission / reception. The duration / ID field can be set to a time for transmitting a corresponding frame, etc. For details of sequence control, QoS control, and HT control subfields of the MAC header, refer to IEEE 802.11 standard documents.

[0097] The null data PPDU (NDP) format refers to a PPDU format that does not include a data field. In other words, the NDP refers to a frame format that includes a general PPDU format preamble (i.e., L-STF, L-LTF, L-SIG field, and additional non-legacy SIG, non-legacy STF, non-legacy LTF (if present)) and does not include the remaining part (i.e., data field).

[0098] Figure 7 is a diagram illustrating an example of a PPDU defined in an IEEE 802.11 standard to which the disclosure can be applied.

[0099] In standards such as IEEE 802.11a / g / n / ac / ax, various types of PPDUs have been used. A basic PPDU format (IEEE 802.11a / g) includes L-LTF, L-STF, L-SIG, and a data field. The basic PPDU format can also be referred to as a non-HT PPDU format (asindicated in (a) of FIG. 1). Figure 7

[0100] Compared to the basic PPDU format, the HT PPDU format (IEEE 802.11n) additionally includes HT-SIG, HT-STF, and HT-LFT fields. Figure 7 The HT PPDU format illustrated in (b) of FIG. 1 can be referred to as an HT mixed format. In addition, an HT greenfield format PPDU can be defined, and this corresponds to a format (not shown) consisting of HT-GF-STF, HT-LTF1, HT-SIG, one or more HT-LTFs, and a data field, excluding L-STF, L-LTF, and L-SIG.

[0101] Compared to the basic PPDU format, an example of the VHT PPDU format (IEEE 802.11ac) additionally includes VHTSIG-A, VHT-STF, VHT-LTF, and VHT-SIG-B fields (asFigure 7 (as shown in (c)).

[0102] Compared to the basic PPDU format, examples of the HE PPDU format (IEEE 802.11ax) additionally include repeated L-SIG (RL-SIG), HE-SIG-A, HE-SIG-B, HE-STF, HE-LTF, and Packet Extension (PE) fields (such as...). Figure 7 (as shown in (d)). Some fields can be excluded, or their lengths can vary depending on the detailed examples of the HE PPDU format. For example, the HE-SIG-B field is included in the HE PPDU format for multi-user (MU), but not in the HE PPDU format for single-user (SU). Furthermore, the HE-Trigger-Based (TB) PPDU format does not include HE-SIG-B, and the length of the HE-STF field can vary up to 8 μs. The Extended Range (HE ER) SU PPDU format does not include the HE-SIG-B field, and the length of the HE-SIG-A field can vary up to 16 μs. For example, RL-SIG can be configured to be the same as L-SIG. Based on the presence of RL-SIG, the receiving STA can determine whether the received PPDU is an HE PPDU or an EHT PPDU, which will be described later.

[0103] EHT PPDU format can include Figure 7 EHT MU (Multi-user) in (e) and Figure 7 The EHT TB (trigger-based) PPDU in (f). The EHT PPDU format is similar to the HE PPDU format in that it includes RL-SIG following L-SIG, but it can include U (generic)-SIG, EHT-SIG, EHT-STF and EHT-LTF following RL-SIG.

[0104] Figure 7 In (e), the EHT MU PPDU corresponds to a PPDU carrying one or more data (or PSDU) for one or more users. That is, the EHT MU PPDU can be used for both SU and MU transmissions. For example, the EHT MU PPDU can correspond to a PPDU for one or more receiving STAs.

[0105] Compared to EHT MU PPDU, Figure 7 In (f), the EHT-SIG is omitted from the EHT TB PPDU. The STA that receives the trigger for UL MU transmission (e.g., trigger frame or trigger response schedule (TRS)) can perform UL transmission based on the EHT TB PPDU format.

[0106] L-STF, L-LTF, L-SIG, RL-SIG, U-SIG (Universal Signal), EHT-SIG field can be encoded and modulated so that even legacy STAs can attempt to demodulate and decode, and can be mapped based on the determined subcarrier spacing (e.g., 312.5 kHz). These can be referred to as pre-EHT modulation fields. Next, EHT-STF, EHT-LTF, data, PE field can be encoded and modulated to be demodulated and decoded by STAs that successfully decoded non-legacy SIG (e.g., U-SIG and / or EHT-SIG) and obtained the information included in the field, and can be mapped based on the determined subcarrier spacing (e.g., 78.125 kHz). These can be referred to as EHT modulation fields.

[0107] Similarly, in HE PPDU format, L-STF, L-LTF, L-SIG, RL-SIG, HE-SIG-A, and HE-SIG-B field can be referred to as pre-HE modulation fields, and HE-STF, HE-LTF, data, and PE field can be referred to as HE modulation fields. In addition, in VHT PPDU format, L-STF, L-LTF, L-SIG, and VHT-SIG-A field can be referred to as non-VHT modulation fields, and VHT STF, VHT-LTF, VHT-SIG-B, and data field can be referred to as VHT modulation fields.

[0108] The U-SIG included in the EHT PPDU format of Figure 7 The U-SIG can be configured based on, for example, two symbols (e.g., two consecutive OFDM symbols). Each symbol (e.g., OFDM symbol) for the U-SIG can have a duration of 4 µs, and the U-SIG can have a total duration of 8 µs. Each symbol of the U-SIG can be used to transmit 26 bits of information. For example, each symbol of the U-SIG can be transmitted and received based on 52 data tones and 4 pilot tones.

[0109] The U-SIG can be constructed in units of 20 MHz. For example, if an 80 MHz PPDU is constructed, the U-SIG can be duplicated. That is, the same 4 U-SIGs can be included in the 80 MHz PPDU. A PPDU exceeding the 80 MHz bandwidth can include a different U-SIG.

[0110] For example, A uncoded bits can be transmitted through the U-SIG, a first symbol of the U-SIG (e.g., U-SIG-1 symbol) can transmit a first X bits of the total A bits of information, and a second symbol of the U-SIG (e.g., U-SIG-2 symbol) can transmit a remaining Y bits of the total A bits of information. The A bits of information (e.g., 52 uncoded bits) can include a CRC field (e.g., 4-bit long field) and a tail field (e.g., 6-bit long field). For example, the tail field can be used to terminate a trellis structure of a convolutional decoder and can be set to 0.

[0111] The bits of information transmitted through the U-SIG can be divided into version-independent bits and version-dependent bits. For example, the U-SIG can be included in a new PPDU format (e.g., UHR PPDU format) not shown in Figure 7 and in the format of the U-SIG field included in the EHT PPDU format and the format of the U-SIG field included in the UHR PPDU format, the version-independent bits can be the same, and some or all of the version-dependent bits can be different.

[0112] For example, the size of the version-independent bits of the U-SIG can be fixed or variable. The version-independent bits can be assigned to only the U-SIG-1 symbol or to both the U-SIG-1 symbol and the U-SIG-2 symbol. The version-independent bits and the version-dependent bits can be referred to by various names, such as first control bits and second control bits.

[0113] For example, the version-independent bits of the U-SIG can include a 3-bit physical layer version identifier (PHY version identifier), and this information can indicate a PHY version (e.g., EHT, UHR, etc.) of a transmitted / received PPDU. The version-independent bits of the U-SIG can include a 1-bit UL / DL flag field. A first value of the 1-bit UL / DL flag field is related to UL communication, and a second value of the UL / DL flag field is related to DL communication. The version-independent bits of the U-SIG can include information about a length of a transmit opportunity (TXOP) and information about a BSS color ID.

[0114] For example, the version-dependent bits of the U-SIG can include information that directly or indirectly indicates a type of the PPDU (e.g., SU PPDU, MU PPDU, TB PPDU, etc.).

[0115] Information required for PPDU transmission and reception can be included in the U-SIG. For example, the U-SIG can further include information on a bandwidth, information on an MCS technique applied to a non-legacy SIG (e.g., EHT-SIG or UHR-SIG, etc.), information indicating whether a DCM (Dual Carrier Modulation) technique (e.g., a technique for achieving an effect similar to frequency diversity by reusing the same signal on two subcarriers) is applied to the non-legacy SIG, information on the number of symbols used for the non-legacy SIG, information on whether the non-legacy SIG is generated across the entire frequency band.

[0116] Some of the information required for PPDU transmission and reception can be included in the U-SIG and / or the non-legacy SIG (e.g., EHT-SIG or UHR-SIG, etc.). For example, information on the type of non-legacy LTF / STF (e.g., EHT-LTF / EHT-STF or UHR-LTF / UHR-STF, etc.), information on the length of the non-legacy LTF and the CP (Cyclic Prefix) length, information on the GI (Guard Interval) applicable to the non-legacy LTF, information on the preamble puncturing applicable to the PPDU, information on the resource unit (RU) allocation, etc. can be included only in the U-SIG, only in the non-legacy SIG, or can be indicated by a combination of the information included in the U-SIG and the information included in the non-legacy SIG.

[0117] Preamble puncturing can denote transmission of a PPDU in which there is no signal in one or more frequency units among the bandwidth of the PPDU. For example, the size of the frequency unit (or the resolution of the preamble puncturing) can be defined as 20 MHz, 40 MHz, etc. For example, the preamble puncturing can be applied to a PPDU bandwidth of a predetermined size or more.

[0118] In an example of Figure 7 , a non-legacy SIG such as HE-SIG-B and EHT-SIG can include control information for a receiving STA. The non-legacy SIG can be transmitted on at least one symbol, and one symbol can have a length of 4 µs. Information on the number of symbols used for the EHT-SIG can be included in a previous SIG (e.g., HE-SIG-A, U-SIG, etc.).

[0119] A non-legacy SIG such as HE-SIG-B and EHT-SIG can include a common field and a user-specific field. The common field and the user-specific field can be encoded separately.

[0120] In some cases, the common field can be omitted. For example, in a compressed mode applying non-OFDMA (orthogonal frequency division multiple access), the common field can be omitted, and multiple STAs can receive a PPDU (e.g., a data field of the PPDU) through the same frequency band. In a non-compressed mode applying OFDMA, multiple users can receive a PPDU (e.g., a data field of the PPDU) through different frequency bands.

[0121] The number of user-specific fields can be determined based on the number of users. One user block field can include up to two user fields. Each user field can be associated with a MU-MIMO allocation, or can be associated with a non-MU-MIMO allocation.

[0122] The common field can include a CRC bit and a tail bit, and the length of the CRC bit can be determined as 4 bits, and the length of the tail bit can be determined as 6 bits and set to 000000. The common field can include RU allocation information. The RU allocation information can include information about the positions of RUs to which a plurality of users (i.e., a plurality of receiving STAs) are assigned.

[0123] An RU can include a plurality of subcarriers (or tones). The RU can be used when a signal is transmitted to a plurality of STAs based on an OFDMA technology. In addition, even when a signal is transmitted to one STA, an RU can be defined. A non-legacy STF, a non-legacy LTF, and a data field can be allocated in units of RUs.

[0124] An RU of an applicable size can be defined according to a PPDU bandwidth. The RUs can be defined identically or differently for applied PPDU formats (e.g., HE PPDU, EHT PPDU, UHR PPDU, etc.). For example, in the case of an 80 MHz PPDU, the RU layout of HE PPDU and EHT PPDU can be different. The applicable RU size, the number and position of RUs, the position and number of DC (direct current) subcarriers, the position and number of null subcarriers, the position and number of guard subcarriers, etc. per PPDU bandwidth can be referred to as a tone plan. For example, a tone plan for a high bandwidth can be defined in the form of multiple iterations of a low bandwidth tone plan.

[0125] RUs of various sizes can be defined as 26-tone RUs, 52-tone RUs, 106-tone RUs, 242-tone RUs, 484-tone RUs, 996-tone RUs, 2×996-tone RUs, 3×996-tone RUs, etc. MRUs (Multiple RUs) differ from multiple individual RUs and correspond to a group of subcarriers composed of multiple RUs. For example, an MRU can be defined as 52+26-tone, 106+26-tone, 484+242-tone, 996+484-tone, 996+484+242-tone, 2×996+484-tone, 3×996-tone, or 3×996+484-tone. Furthermore, the multiple RUs constituting an MRU can be consecutive or non-consecutive in the frequency domain.

[0126] The specific size of the RU can be reduced or expanded. Therefore, the specific size of each RU in this disclosure (i.e., the number of corresponding tones) is not limiting but illustrative. In addition, in this disclosure, the number of RUs can vary depending on the RU size within a predetermined bandwidth (e.g., 20MHz, 40MHz, 80MHz, 160MHz, 320MHz...).

[0127] Figure 7 The names of each field in the PPDU format are exemplary, and the scope of this disclosure is not limited to these names. Furthermore, the examples in this disclosure can be applied to… Figure 7 The PPDU format shown and based on Resource unit A new PPDU format that excludes some fields and / or adds some fields, based on the PPDU format.

[0128] Figures 8 to 10

[0129] Figures 8 to 10 This is a diagram illustrating an example of a resource unit that can be used in a WLAN system according to this disclosure.

[0130] Reference Figures 8 to 10 This section describes the Resource Unit (RU) defined in a wireless LAN system. An RU can include multiple subcarriers (or tones). RUs can be used when transmitting signals to multiple STAs based on an OFDMA scheme. Additionally, RUs can be defined even when a signal is being transmitted to a single STA. RUs can be used for the data field, STF, LTF, etc., of a PPDU.

[0131] like Figure 8As shown in the middle, RUs corresponding to different numbers of tones (i.e., subcarriers) are used to construct some fields of a 20MHz, 40MHz, or 80MHz X-PPDU (X is HE, EHT, etc.). For example, resources can be allocated in RU units shown for X-STF, X-LTF, and data fields.

[0132] Figure 8 is a diagram illustrating an exemplary allocation of resource units (RUs) used on a 20MHz band.

[0133] As shown at the top of Figure 8 , 26-unit (i.e., a unit corresponding to 26 tones) can be allocated. 6 tones can be used as a guard band in the leftmost band of the 20MHz band, and 5 tones can be used as a guard band in the rightmost band of the 20MHz band. In addition, 7 DC tones are inserted in the center band (that is, the DC band), and 26-unit corresponding to each of the 13 tones can exist on the left and right of the DC band. In addition, 26-unit, 52-unit, and 106-unit can be allocated to other bands. Each unit can be allocated to a STA or a user.

[0134] Figure 8 The RU allocation of Figure 8 is not only used for a multi-user (MU) case, but also for a single-user (SU) case, and in this case, one 242-unit can be used, as shown at the bottom of Figure 8 . In this case, three DC tones can be inserted.

[0135] In the example of Figure 9 , various sizes of RUs are illustrated, that is, 26-RU, 52-RU, 106-RU, 242-RU, etc., but the specific sizes of these RUs can be reduced or enlarged. Therefore, in the present disclosure, the specific size of each RU (i.e., the number of corresponding tones) is exemplary, not limiting. In addition, within a predetermined bandwidth (e.g., 20MHz, 40MHz, 80MHz, 160MHz, 320MHz,...) in the present disclosure, the number of RUs can vary depending on the size of the RU. In the example of Figure 10 and / or Figure 8 , the fact that the size and / or number of RUs can vary is the same as in the example of Figure 9 .

[0136] Figure 8 is a diagram illustrating an exemplary allocation of resource units (RUs) used on a 40MHz band.

[0137] Just as various sizes of RUs are used in the example of Figure 9 , various sizes of RUs can also be used in the example ofFigure 10 Examples use 26-RU, 52-RU, 106-RU, 242-RU, 484-RU, etc. Additionally, 5 DC tones can be inserted at the center frequency, 12 tones can be used as guard bands in the leftmost band of the 40MHz band, and 11 tones can be used as guard bands in the rightmost band of the 40MHz band.

[0138] Additionally, as shown, a 484-RU can be used when for single-user applications.

[0139] Figure 8 This is a diagram illustrating an exemplary allocation of resource units (RUs) used in the 80MHz band.

[0140] As in Figure 9 and Figure 10 Just like the examples that use RUs of various sizes, it is also possible to... Figure 10 Examples use 26-RU, 52-RU, 106-RU, 242-RU, 484-RU, 996-RU, etc. Additionally, in the case of an 80MHz PPDU, the RU allocation for the HE PPDU and EHT PPDU can be different, and... Figure 10 The example shows an example of RU allocation for an 80MHz EHT PPDU. Figure 10 The example uses 12 tones as guard bands in the leftmost band of the 80MHz band and 11 tones as guard bands in the rightmost band of the 80MHz band, the same scheme as in the HE PPDU and EHT PPDU. Unlike the HE PPDU, where 7 DC tones are inserted into the DC band and there is a 26-RU corresponding to each of the 13 tones on the left and right sides of the DC band, in the EHT PPDU, 23 DC tones are inserted into the DC band, and there is a 26-RU on the left and right sides of the DC band. Unlike the HE PPDU, where one empty subcarrier exists between 242 RUs instead of in the center band, there are five empty subcarriers in the EHT PPDU. In the HE PPDU, a 484-RU does not include an empty subcarrier, but in the EHT PPDU, a 484-RU includes 5 empty subcarriers.

[0141] Additionally, as shown, when used for a single user, the 996-RU can be used, and in this case, like the HEPPDU and EHT PPDU, five DC tones are inserted.

[0142] exist Figure 10 In this configuration, an EHT PPDU on 160MHz can be configured with multiple 80MHz sub-blocks. The RU allocation for each 80MHz sub-block can be... Figure 10RU allocation of the 80MHz EHT PPDU is the same. If an 80MHz sub-block of the 160MHz or 320MHz EHT PPDU is not punctured and the entire 80MHz sub-block is used as a part of an RU or a Multiple RUs (MRU), the 80MHz sub-block can use Distributed resource unit a 996-RU of the 80MHz EHT PPDU.

[0143] Here, the MRU corresponds to a group of subcarriers (or tones) composed of a plurality of RUs, and the plurality of RUs constituting the MRU can be RUs having the same size or RUs having different sizes. For example, a single MRU can be defined as 52+26-tone, 106+26-tone, 484+242-tone, 996+484-tone, 996+484+242-tone, 2x996+484-tone, 3x996-tone, or 3x996+484-tone. Here, the plurality of RUs constituting one MRU can correspond to a small size (e.g., 26, 52, or 106) RU or a large size (e.g., 242, 484, or 996) RU. That is, one MRU including a small size RU and a large size RU can not be configured / defined. In addition, the plurality of RUs constituting one MRU can be continuous in the frequency domain, or can not be continuous.

[0144] When the 80MHz sub-block includes an RU of less than 996 tones or a part of the 80MHz sub-block is punctured, the 80MHz sub-block can use an RU allocation other than the 996-tone RU.

[0145] The RU of the disclosure can be used for uplink (UL) and / or downlink (DL) communication. For example, when performing trigger-based UL-MU communication, a STA (e.g., an AP) that transmits a trigger can allocate a first RU (e.g., 26 / 52 / 106 / 242-RU, etc.) to a first STA and a second RU (e.g., 26 / 52 / 106 / 242-RU, etc.) to a second STA through trigger information (e.g., a trigger frame or a Trigger Response Schedule (TRS)). Thereafter, the first STA can transmit a first Trigger-Based (TB) PPDU based on the first RU, and the second STA can transmit a second TB PPDU based on the second RU. The first / second TB PPDUs can be transmitted to the AP in the same time period.

[0146] For example, when a DL MU PPDU is configured, a STA (e.g., an AP) that transmits the DL MU PPDU can allocate a first RU (e.g., 26 / 52 / 106 / 242-RU, etc.) to a first STA and a second RU (e.g., 26 / 52 / 106 / 242-RU, etc.) to a second STA. In other words, the transmitting STA (e.g., an AP) can transmit an X-STF (e.g., X is HE, EHT, etc.), X-LTF, and data fields for the first STA through a first RU within one MU PPDU, and can transmit an X-STF, X-LTF, and data fields for the second STA through a second RU. Information about the arrangement of the RUs can be signaled through an X-SIG (e.g., X is HE, EHT, U) field of the X-PPDU format.

[0147] Figure 11

[0148] Due to regulations in each region, a limit on a power spectral density (PSD) can be applied in a sub-7 GHz (e.g., 6 GHz) band. For a non-AP STA in a low power indoor (LPI) band, the PSD limit can be -1 dBm / MHz. For example, for an existing 52-tone RU, the maximum transmission (Tx) power can be about 6 dBm.

[0149] In addition, different limits can be applied in a 2.4 GHz band and a 5 GHz band. For example, in the EU / China / Japan / Korea, a PSD limit of 10 dBm / MHz can be applied in the 2.4 GHz band. For an existing 52-tone RU, the maximum Tx power can be about 17 dBm. If the PSD limit can be avoided in the 5 GHz band, the transmission power can be increased. For example, the maximum transmission power for an existing 52-tone RU is 24 dBm, which is still 6 dBm lower than the maximum allowed effective isotropic radiated power of 30 dBm.

[0150] When the PSD limit is overcome, the transmission power can be increased, thereby improving the spectral efficiency or extending the range.

[0151] Considering that the PSD limit is defined per MHz for each STA, when the tones of a small RU are distributed over a wide bandwidth, the tones for each STA are non-continuous, and thus each tone can be transmitted with high power. An RU including tones distributed in this manner is referred to as a distributed RU (DRU), and in order to distinguish it, an RU including continuous tones defined in an existing WLAN system (e.g., a system according to IEEE 802.11ax, 11be, etc.) can be referred to as a regular RU (RRU).

[0152] A STA transmitting a DRU can use high power compared to a STA transmitting an existing RRU. For example, a 52-tone DRU across 80MHz has only one tone per MHz, whereas for a 52-tone RRU, there are approximately 13 tones per MHz. When assuming a PSD limit of -1dBm / MHz in a 6GHz LPI band, for a 52-tone RU, the transmit power can increase by approximately 11dB when using a DRU. When increasing the transmit power in this way, a higher MCS can be applied and a longer range can be supported.

[0153] Figure 11 FIG. is a diagram for explaining an example to which a DRU of the disclosure can be applied.

[0154] Trigger frame An example of FIG. illustratively shows that STA1 performs transmission on DRU1, STA2 performs transmission on DRU2, and STA3 performs transmission on DRU3. Each STA can apply a transmit power boost by using a DRU. Higher transmit power is applied to all tones in a DRU compared to when the same size RRU is used, and thus, the spectral efficiency can be greatly improved. In this way, a DRU can be usefully applied, especially in UL OFDMA.

[0155] In the case of an AP, a DRU can also be utilized. In some cases, the AP can perform DL-OFDMA transmission to STAs by using only some of DRU1, DRU2, and DRU3, and in this case, a transmit power boost due to the use of a DRU can be applied.

[0156] To maximize the power boost, tones within one DRU can be distributed as far as possible. For example, a DRU including one tone per MHz can be considered a preferred example. The size of a DRU (or the number of available tones included in one DRU (i.e., the number of remaining tones excluding unavailable tones such as null tones, guard tones, DC tones)) can be defined to be the same as the size of an RRU (or the number of available tones included in one RRU). Thus, the impact on various technologies defined based on an RRU previously can be minimized. The following table shows an example of the achievable power boost (in dB) for various DRUs distributed over different bandwidths. The example in the following table assumes a 6GHz LPI band, and power boosts can also be obtained in other regions, in the 2.4GHz band and the 5GHz band. For example, in an 80MHz UL-OFDMA transmission by 8 users, when each user uses a 106-tone DRU, the overall performance can be boosted by approximately 8.13dB compared to when each user uses a 106-tone RRU. In this way, a DRU can be used to overcome a PSD limit and obtain significant benefits.

[0157] [Table 1]

[0158]

[0159] Figure 12

[0160] Figure 12 is a diagram representing an example format of a trigger frame to which the present disclosure can be applied.

[0161] The trigger frame can allocate resources for and request TB PPDU transmission for at least one TB PPDU. The trigger frame can also include other information required for STAs to transmit the TB PPDUs in response thereto. The trigger frame can include a common info and a user info list field in the frame body.

[0162] The common info field can include information commonly applied to at least one TB PPDU transmission requested by the trigger frame, for example, a trigger type, an UL length, whether there is a subsequent trigger frame (e.g., more TF), whether channel sensing (CS) is required, an UL bandwidth (BW), etc. Figure 12 An EHT variant common info field format is exemplarily shown.

[0163] The trigger type subfield of 4 bits in size can have values of 0-15. Among them, values 0, 1, 2, 3, 4, 5, 6, and 7 of the trigger type subfield are defined to correspond to basic, BFRP (Beamforming Report Poll), MU-BAR (Multi-User-Block Ack Request), MU-RTS (Multi-User-Request to Send), BSRP (Buffer Status Report Poll), GCR (Groupcast with Retry) MU-BAR, BQRP (Bandwidth Query Report Poll), and NFRP (NDP Feedback Report Poll), and values 8-15 are defined to be reserved.

[0164] Among the common info, a trigger-related common info subfield can include information selectively included based on the trigger type.

[0165] A special user info field can be included in the trigger frame. The special user info field does not include user-specific information, but includes extended common info not provided in the common info field.

[0166] The user info list includes at least 0 user info field. Transmission and reception based on DRU tone plan An EHT variant user info field format is exemplarily shown.

[0167] The AID 12 subfield basically indicates that it is a user information field for a STA having a corresponding AID. In addition, when the AID 12 field has a predetermined specific value, it can be used for other purposes, such as allocating a random access (RA)-RU or being configured in the form of a special user information field. The special user information field is a user information field that does not include user-specific information but includes extended common information that is not provided in the common information field. For example, the special user information field can be identified by an AID 12 value of 2007, and a special user information field flag subfield in the common information field can indicate whether the special user information field is included.

[0168] The RU allocation subfield can indicate the size and location of the RU / MRU. To this end, the RU allocation subfield can be interpreted together with the PS 160 (primary / secondary 160 MHz) subfield of the user information field, the UL BW subfield of the common information field, etc.

[0169] For example, as in Table 2 below, the mapping of B7-B1 of the RU allocation subfield can be defined together with the settings of B0 and the PS 160 subfield of the user information field. Table 2 shows an example of encoding of the PS 160 subfield of the EHT variant user information field and the RU allocation subfield.

[0170] [Table 2]

[0171]

[0172]

[0173]

[0174] When B0 of the RU allocation subfield is set to 0, it can indicate that the RU / MRU allocation is applied to the primary 80 MHz channel, and when this value is set to 1, it can indicate that the RU allocation is applied to the secondary 80 MHz channel of the primary 160 MHz. When B0 of the RU allocation subfield is set to 0, it can indicate that the RU / MRU allocation is applied to the low 80 MHz of the secondary 160 MHz, and when this value is set to 1, it can indicate that the RU allocation is applied to the high 80 MHz of the secondary 160 MHz.

[0175] In the trigger frame RU allocation table in Table 2, parameter N can be calculated based on the formula N = 2 * X1 + X0. For bandwidths less than or equal to 80MHz, the values ​​of PS160, B0, X0, and X1 can be set to 0. For 160MHz and 320MHz bandwidths, the values ​​of PS160, B0, X0, and X1 can be set as shown in Table 3. This configuration represents the absolute frequency order for the primary and secondary 80MHz and 160MHz channels. The order from left to right represents the order from low frequency to high frequency. The primary 80MHz channel is indicated as P80, the secondary 80MHz channel is indicated as S80, and the secondary 160MHz channel is indicated as S160.

[0176] [Table 3]

[0177]

[0178] Figure 8

[0179] As mentioned above, in order to overcome the PSD limitation and improve power gain, a DRU using distributed tone / subcarriers can be applied instead of an RRU using continuous tone / subcarriers.

[0180] In this disclosure, definitions of DRU tone schemes of various sizes and transmission / reception schemes based thereon are described for DRU-based transmission / reception via PPDU in bandwidths / channels of 40 MHz or greater.

[0181] Specifically, this disclosure proposes a tone scheme for applying DRU-based transmission / reception within each 20MHz channel in the case of performing DRU-based PPDU transmission / reception in a bandwidth of 40MHz or greater.

[0182] The tone scheme for each 20MHz channel may include support for existing technologies (e.g., Figure 9 Examples of RRUs of various sizes and examples of DRUs of various sizes according to this disclosure are provided. In a tone scheme for applying DRUs, the number of tones / subcarriers included in each DRU (i.e., the DRU size) is the same as the number of tones / subcarriers included in the corresponding RRU (i.e., the RRU size), but the position of each tone / subcarrier in the frequency domain can be defined differently. For example, in a bandwidth of 40 MHz or greater, tone schemes supporting 26-tone DRUs, 52-tone DRUs, and 106-tone DRUs can be defined for each 20 MHz channel; however, a 242-tone DRU may not support the distribution of tone / subcarriers and is therefore not included in the examples of this disclosure.

[0183] In examples of the disclosure, the number and location of DC subcarriers, null subcarriers, and guard subcarriers are assumed to be the same as those of the RRU tone plan of the 40MHz bandwidth in the DRU tone plans for the lower 20MHz channel (i.e., the 20MHz channel located at a relatively lower frequency in the frequency domain) and the higher 20MHz channel (i.e., the 20MHz channel located at a relatively higher frequency in the frequency domain) within the 40MHz bandwidth (e.g., Figure 13 ). That is, among the 512 subcarriers in the 40MHz bandwidth, the DC subcarriers correspond to the 5 subcarriers in the middle of the 40MHz bandwidth, and the guard subcarriers can correspond to the 12 subcarriers at the leftmost side and the 11 subcarriers at the rightmost side of the 40MHz bandwidth. The null subcarriers correspond to the 16 subcarriers (subcarrier indices -244, -191, -190, -137, -110, -57, -56, -3, 3, 56, 57, 110, 137, 190, 191, 244) for the 26-tone DRU and the 52-tone DRU, and correspond to the 8 subcarriers (subcarrier indices -244, -137, -110, -3, 3, 110, 137, 244) for the 106-tone DRU (i.e., among the 16 null subcarriers considered in the 26-tone DRU and the 52-tone DRU, 8 null subcarrier positions are used as available subcarriers in the 106-tone DRU).

[0184] In addition, the disclosure proposes a method of utilizing the existing defined pilot subcarriers (e.g., the pilot subcarriers defined in IEEE 802.11 be) in a scenario of transmitting / receiving a PPDU based on a DRU in a 40MHz or greater bandwidth.

[0185] For example, for a 20MHz channel or a 40MHz channel, the indices of the pilot subcarriers transmitted for the 26-tone RRU can be defined as in Table 4, the indices of the pilot subcarriers transmitted for the 52-tone RRU can be defined as in Table 5, the indices of the pilot subcarriers transmitted for the 106-tone RRU can be defined as in Table 6, and the indices of the pilot subcarriers transmitted for the 242-tone RRU can be defined as in Table 7.

[0186] [Table 4]

[0187]

[0188] [Table 5]

[0189]

[0190] [Table 6]

[0191]

[0192] [Table 7]

[0193]

[0194] Specifically, in the examples described in the present disclosure, the pilot subcarriers of the DRU tone plan for the 40MHz or greater bandwidth can be configured / defined / assigned based on the positions of the pilot subcarriers in the RRU tone plan for the 40MHz or greater bandwidth.

[0195] In the following description, the subcarriers within the bandwidth except for the DC subcarriers, null subcarriers, guard subcarriers, and pilot subcarriers can be referred to as available subcarriers.

[0196] In the present disclosure, as a representative example, the DRU tone plan for the lower 20MHz channel and the upper 20MHz channel within the 40MHz bandwidth is proposed.

[0197] Through the extended application of the DRU tone plan, the DRU tone plan (i.e., DRU tone index) including each 20MHz channel in a wider bandwidth (e.g., 80MHz / 160MHz / 240MHz / 320MHz / 480MHz / 640MHz bandwidth, etc.) can be defined.

[0198] In this regard, the present disclosure defines the data tone index in the available subcarriers and proposes a method for selecting the pilot subcarriers / tone.

[0199] Specifically, when a large size DRU tone plan determined by the combination of small size DRU tone plans is configured, it can be assumed that the form before the pilot subcarriers are merged in the small size DRU tone plans and / or the form before some of the pilot subcarriers are converted into data subcarriers is combined to define the index of the data subcarriers. At this time, the case where the null subcarriers are merged with the data subcarriers in the small size DRU tone plans can be considered. Then, by defining the index of the pilot subcarriers and considering the case where some of the pilot subcarriers are changed to data subcarriers, the final DRU, i.e., the DRU tone plan, can be formed / defined.

[0200] Figure 13 is a diagram for explaining an example of a DRU tone plan-based PPDU reception method of a first STA according to the present disclosure.

[0201] In step S1310, the first STA can generate a PPDU including one or more fields mapped onto one or more DRUs. The PPDU can be a PPDU transmitted / received over a bandwidth including a first 20MHz channel and a second 20MHz channel. Here, the first 20MHz channel means a 20MHz channel located at a relatively lower frequency in a 40MHz bandwidth, and the second 20MHz channel can mean a 20MHz channel located at a relatively higher frequency in the 40MHz bandwidth.

[0202] For example, the at least one field can include a data field. In other words, the data field of the PPDU can be generated by being mapped on at least one DRU of various sizes.

[0203] If the one or more DRUs include 26-tone DRUs, the 26-tone DRUs can be one of 9 predefined 26-tone DRUs.

[0204] For each of the first 20MHz channel and the second 20MHz channel, an n-th (n=1, 2,..., 9) 26-tone DRU can include an n-th lowest subcarrier among available subcarriers. Also, the n-th (n=1, 2,..., 9) 26-tone DRU can include every 9th subcarrier based on the n-th lowest subcarrier.

[0205] Here, the available subcarriers in the first 20MHz channel and the available subcarriers in the second 20MHz channel can include, among subcarriers in a 40MHz channel including the first 20MHz channel and the second 20MHz channel, excluding 5 DC (direct current) subcarriers, 16 null subcarriers, 23 guard subcarriers, and 36 pilot subcarriers among 512 subcarriers. That is, the available subcarriers within the 40MHz channel can be configured with the available subcarriers in the first 20MHz channel and the available subcarriers in the second 20MHz channel.

[0206] For example, with respect to the first 20 MHz channel, a first 26-tone DRU can include subcarrier indices -243, -233, -223, -214, -204, -194, -182, -173, -163, -153, -143, -133, -123, -113, -102, -93, -83, -73, -63, -52, -42, -32, -22, and -13. A second 26-tone DRU can include subcarrier indices -242, -232, -222, -213, -203, -193, -181, -172, -162, -152, -142, -132, -122, -112, -101, -92, -82, -72, -62, -51, -41, -31, -21, and -12. A third 26-tone DRU can include subcarrier indices -241, -231, -221, -211, -202, -192, -180, -171, -161, -151, -141, -131, -121, -111, -100, -91, -81, -71, -61, -49, -40, -30, -20, and -11. A fourth 26-tone DRU can include subcarrier indices -240, -230, -220, -210, -201, -189, -179, -169, -160, -150, -140, -129, -120, -109, -99, -89, -80, -70, -60, -48, -39, -29, -19, and -9. A fifth 26-tone DRU can include subcarrier indices -239, -229, -219, -209, -200, -188, -178, -168, -159, -149, -139, -128, -119, -108, -98, -88, -79, -69, -59, -47, -38, -28, -18, and -8. A sixth 26-tone DRU can include subcarrier indices -237, -228, -218, -208, -199, -187, -177, -167, -157, -148, -138, -127, -118, -107, -97, -87, -77, -68, -58, -46, -37, -27, -17, and -7. A seventh 26-tone DRU can include subcarrier indices -236, -227, -217, -207, -197, -186, -176, -166, -156, -147, -136, -126, -117, -106, -96, -86, -76, -67, -55, -45, -35, -26, -16, and -6.An eighth 26-tone DRU can include subcarrier indices -235, -226, -216, -206, -196, -185, -175, -165, -155, -146, -135, -125, -115, -105, -95, -85, -75, -66, -54, -44, -34, -25, -15, and -5. A ninth 26-tone DRU can include subcarrier indices -234, -225, -215, -205, -195, -183, -174, -164, -154, -145, -134, -124, -114, -103, -94, -84, -74, -65, -53, -43, -33, -23, -14, and -4.

[0207] For example, with respect to the second 20 MHz channel, the first 26-tone DRU can include subcarrier indices 4, 14, 23, 33, 43, 53, 65, 74, 84, 94, 103, 114, 124, 134, 145, 154, 164, 174, 183, 195, 205, 215, 225, and 234. The second 26-tone DRU can include subcarrier indices 5, 15, 25, 34, 44, 54, 66, 75, 85, 95, 105, 115, 125, 135, 146, 155, 165, 175, 185, 196, 206, 216, 226, and 235. The third 26-tone DRU can include subcarrier indices 6, 16, 26, 35, 45, 55, 67, 76, 86, 96, 106, 117, 126, 136, 147, 156, 166, 176, 186, 197, 207, 217, 227, and 236. The fourth 26-tone DRU can include subcarrier indices 7, 17, 27, 37, 46, 58, 68, 77, 87, 97, 107, 118, 127, 138, 148, 157, 167, 177, 187, 199, 208, 218, 228, and 237. The fifth 26-tone DRU can include subcarrier indices 8, 18, 28, 38, 47, 59, 69, 79, 88, 98, 108, 119, 128, 139, 149, 159, 168, 178, 188, 200, 209, 219, 229, and 239. The sixth 26-tone DRU can include subcarrier indices 9, 19, 29, 39, 48, 60, 70, 80, 89, 99, 109, 120, 129, 140, 150, 160, 169, 179, 189, 201, 210, 220, 230, and 240. The seventh 26-tone DRU can include subcarrier indices 11, 20, 30, 40, 49, 61, 71, 81, 91, 100, 111, 121, 131, 141, 151, 161, 171, 180, 192, 202, 211, 221, 231, and 241. The eighth 26-tone DRU can include subcarrier indices 12, 21, 31, 41, 51, 62, 72, 82, 92, 101, 112, 122, 132, 142, 152, 162, 172, 181, 193, 203, 213, 222, 232, and 242. The ninth 26-tone DRU can include subcarrier indices 13, 22, 32, 42, 52, 63, 73, 83, 93, 102, 113, 123, 133, 143, 153, 163, 173, 182, 194, 204, 214, 223, 233, and 243.

[0208] Additionally, with respect to the first 20 MHz channel, the two pilot subcarriers for the nth26-tone DRU can be based on the two subcarrier indices included in the first subcarrier index set {-238, -224, -212, -198, -184, -170, -158, -144, -130, -116, -104, -90, -78, -64, -50, -36, -24, -10}. Additionally, with respect to the second 20 MHz channel, the two pilot subcarriers for the nth26-tone DRU can be based on the two subcarrier indices included in the second subcarrier index set {10, 24, 36, 50, 64, 78, 90, 104, 116, 130, 144, 158, 170, 184, 198, 212, 224, 238}.

[0209] In this regard, when the mapping relationship between the nine predefined 26-tone DRUs and the nine 26-tone RUs is defined, the two pilot subcarriers for the nth26-tone DRU can correspond to the predefined two pilot subcarriers for the 26-tone RU among the 9 26-tone RUs that is mapped to the nth26-tone DRU. In this case, with respect to the first 20 MHz channel, the predefined two pilot subcarriers can be one of pilot subcarrier indices {-238, -224}, {-212, -198}, {-184, -170}, {-158, -144}, {-130, -116}, {-104, -90}, {-78, -64}, {-50, -36}, or {-24, -10}. Additionally, with respect to the second 20 MHz channel, the predefined two pilot subcarriers can be one of pilot subcarrier indices {10, 24}, {36, 50}, {64, 78}, {90, 104}, {116, 130}, {144, 158}, {170, 184}, {198, 212}, or {224, 238}.

[0210] Additionally or alternatively, with respect to the first 20 MHz channel, the two pilot subcarriers for the nth26-tone DRU can correspond to {nthsubcarrier index, (n+9)thsubcarrier index} among the subcarrier indices included in the first subcarrier index set. Further, with respect to the second 20 MHz channel, the two pilot subcarriers for the nth26-tone DRU can correspond to {nthsubcarrier index, (n+9)thsubcarrier index} among the subcarrier indices included in the second subcarrier index set.

[0211] Additionally or alternatively, with respect to the first 20 MHz channel, considering the case that the first pilot subcarrier index set {-238, -212, -170, -144} and the second pilot subcarrier index set {-104, -78, -36, -10} are defined for the predefined first 106-tone RU and the second 106-tone RU (e.g., see Table 6), 18 pilot subcarriers can be defined / assigned for the 9 26-tone DRUs. Specifically, within the first 20 MHz channel, for the first 26-tone DRU to the fourth 26-tone DRU, the subcarrier indices {-238, -212, -170, -144} included in the first subcarrier index set and included in the first pilot subcarrier index set can be assigned one by one as pilot subcarriers, and the subcarrier indices {-90, -64, -50, -24} included in the first subcarrier index set and used as data subcarriers for the predefined second 106-tone RU can be assigned one by one as pilot subcarriers. In addition, for the sixth 26-tone DRU to the ninth 26-tone DRU, the subcarrier indices {-104, -78, -36, -10} included in the first subcarrier index set and included in the second pilot subcarrier index set can be assigned one by one as pilot subcarriers, and the subcarrier indices {-224, -198, -184, -158} included in the first subcarrier index set and used as data subcarriers for the predefined first 106-tone RU can be assigned one by one as pilot subcarriers. In addition, for the fifth 26-tone DRU, the remaining unassigned subcarrier indices (e.g., subcarrier indices {-130, -116}) included in the first subcarrier index set can be assigned as pilot subcarriers.

[0212] Additionally or alternatively, with respect to the second 20 MHz channel, considering the case where a first group of pilot subcarrier indices {10, 36, 78, 104} and a second group of pilot subcarrier indices {144, 170, 212, 238} are defined for the predefined first 106-tone RU and the second 106-tone RU (see, e.g., Table 6), 18 pilot subcarriers can be defined / assigned for the 9 26-tone DRUs. Specifically, within the second 20 MHz channel, for the first 26-tone DRU to the fourth 26-tone DRU, the subcarrier indices {10, 36, 78, 104} included in the first group of subcarrier indices and included in the first group of pilot subcarrier indices can be assigned one by one as pilot subcarriers, and the subcarrier indices {158, 184, 198, 224} included in the first group of subcarrier indices and used as data subcarriers for the predefined second 106-tone RU can be assigned one by one as pilot subcarriers. In addition, for the sixth 26-tone DRU to the ninth 26-tone DRU, the subcarrier indices {144, 170, 212, 238} included in the first group of subcarrier indices and included in the second group of pilot subcarrier indices can be assigned one by one as pilot subcarriers, and the subcarrier indices {24, 50, 64, 90} included in the first group of subcarrier indices and used as data subcarriers for the predefined first 106-tone RU can be assigned one by one as pilot subcarriers. In addition, for the fifth 26-tone DRU, the remaining subcarrier indices (e.g., subcarrier indices {116, 130}) included in the first group of subcarrier indices and not assigned can be assigned as pilot subcarriers.

[0213] Based on the at least one DRU including any one of the 52-tone DRUs, the corresponding 52-tone DRU can be one of the 4 predefined 52-tone DRUs.

[0214] For example, for each of the first 20 MHz channel and the second 20 MHz channel, the first 52-tone DRU can include subcarriers included in the first 26-tone DRU and the sixth 26-tone DRU. The second 52-tone DRU can include subcarriers included in the second 26-tone DRU and the seventh 26-tone DRU. The third 52-tone DRU can include subcarriers included in the third 26-tone DRU and the eighth 26-tone DRU. The fourth 52-tone DRU can include subcarriers included in the fourth 26-tone DRU and the ninth 26-tone DRU.

[0215] Additionally, four pilot subcarriers can be allocated for each of the four predefined 52-tone DRUs. In this case, with respect to the first 20 MHz channel, the four pilot subcarriers can be based on the four subcarrier indices included in the first subcarrier index set {-238, -224, -212, -198, -184, -170, -158, -144, -104, -90, -78, -64, -50, -36, -24, -10}. With respect to the second 20 MHz channel, the four pilot subcarriers can be based on the four subcarrier indices included in the second subcarrier index set {10, 24, 36, 50, 64, 78, 90, 104, 144, 158, 170, 184, 198, 212, 224, 238}.

[0216] In this regard, in the case where the mapping relationship between the four predefined 52-tone DRUs and the four 52-tone RUs is defined, the four pilot subcarriers allocated for each 52-tone DRU can correspond to the four pilot subcarriers predefined for the mapped 52-tone RUs among the four 52-tone RUs. In this case, with respect to the first 20 MHz channel, the predefined four pilot subcarriers can be one of the pilot subcarrier indices {-238, -224, -212, -198}, {-184, -170, -158, -144}, {-104, -90, -78, -64}, or {-50, -36, -24, -10}. Additionally, with respect to the second 20 MHz channel, the predefined four pilot subcarriers can be one of the pilot subcarrier indices {10, 24, 36, 50}, {64, 78, 90, 104}, {144, 158, 170, 184}, or {198, 212, 224, 238}.

[0217] Additionally or alternatively, the four pilot subcarriers (i.e., the four pilot subcarriers allocated for each 52-tone DRU) can correspond to the four pilot subcarriers allocated for the two 26-tone DRUs used to configure the 52-tone DRU.

[0218] Based on the at least one DRU including any one of the 106-tone DRUs 106, the corresponding 106-tone DRU can be one of the 2 predefined 106-tone DRUs.

[0219] For example, for each of the first and second 20 MHz channels, the first 106-tone DRU can include a first group corresponding to two of the four null subcarriers, and subcarriers included in the first and third 52-tone DRUs. The second 106-tone DRU can include a second group corresponding to the other two of the four null subcarriers, and subcarriers included in the second and fourth 52-tone DRUs.

[0220] Here, with respect to the first 20 MHz channel, when indices of the four null subcarriers are -191, -190, -57, and -56, the first group can include subcarrier indices -191 and -57, and the second group can include subcarrier indices -190 and -56. Alternatively, the first group can include subcarrier indices -190 and -56, and the second group can include subcarrier indices -191 and -57. Further, with respect to the second 20 MHz channel, when indices of the four null subcarriers are 56, 57, 190, and 191, the first group can include subcarrier indices 56 and 190, and the second group can include subcarrier indices 57 and 191. Alternatively, the first group can include subcarrier indices 57 and 191, and the second group can include subcarrier indices 56 and 190.

[0221] Further, four pilot subcarriers and four additional data subcarriers can be allocated to each of the two predefined 106-tone DRUs. At this time, for the first 20 MHz channel, the four pilot subcarriers and the four additional data subcarriers can be based on eight subcarrier indices included in a first subcarrier index group {-238, -224, -212, -198, -184, -170, -158, -144, -104, -90, -78, -64, -50, -36, -24, -10}. Further, for the second 20 MHz channel, the four pilot subcarriers and the four additional data subcarriers can be based on eight subcarrier indices included in a second subcarrier index group {10, 24, 36, 50, 64, 78, 90, 104, 144, 158, 170, 184, 198, 212, 224, 238}.

[0222] In this regard, for each of the first and second 20 MHz channels, when two pilot subcarrier index groups are defined for the two predefined 106-tone RUs, indices of the four pilot subcarriers can belong to at least one of the two pilot subcarrier index groups.

[0223] The DRU tone plan is exemplary and the tones / subcarriers included in the 26-tone DRU, 52-tone DRU, and 106-tone DRU can be defined according to various other examples described below.

[0224] When the aforementioned 20 MHz channels correspond to a portion of a bandwidth greater than 40 MHz, the subcarrier indices included in each of the one or more DRUs for the corresponding 20 MHz channel can be shifted according to the location within the greater than 40 MHz bandwidth. In the following description, for reference, the set of subcarrier indices included in each of the one or more DRUs for an x MHz channel within a y MHz bandwidth can be denoted as S_x_y.

[0225] For example, in an 80 MHz bandwidth, the DRU subcarrier indices for each 20 MHz channel within the left 40 MHz channel of the two 40 MHz channels (first S_20_80 and second S_20_80) can correspond to the values obtained by subtracting 256 from the DRU subcarrier indices for each 20 MHz channel defined in a 40 MHz bandwidth (first S_20_40 and second S_20_40). The DRU subcarrier indices for each 20 MHz channel within the right 40 MHz channel of the two 40 MHz channels in an 80 MHz bandwidth (third S_20_80 and fourth S_20_80) can correspond to the values obtained by adding 256 to the DRU subcarrier indices for each 20 MHz channel defined in a 40 MHz bandwidth (first S_20_40 and second S_20_40).

[0226] For example, in an 80 MHz bandwidth, the DRU subcarrier indices for each 20 MHz channel within the left 40 MHz channel of the two 40 MHz channels (first S_20_80 and second S_20_80) can correspond to the values obtained by subtracting 256 from the DRU subcarrier indices for each 20 MHz channel defined in a 40 MHz bandwidth (first S_20_40 and second S_20_40). The DRU subcarrier indices for each 20 MHz channel within the right 40 MHz channel of the two 40 MHz channels in an 80 MHz bandwidth (third S_20_80 and fourth S_20_80) can correspond to the values obtained by adding 256 to the DRU subcarrier indices for each 20 MHz channel defined in a 40 MHz bandwidth (first S_20_40 and second S_20_40).

[0227] For example, among three 80 MHz channels within a 240 MHz bandwidth, the DRU subcarrier indices for each 20 MHz channel within the left 80 MHz channel (first through fourth S_20_240) can respectively correspond to values obtained by subtracting 1024 from the DRU subcarrier indices for each 20 MHz channel defined in an 80 MHz bandwidth (first through fourth S_20_80). The DRU subcarrier indices for each 20 MHz channel within the center 80 MHz channel in the 240 MHz bandwidth (fifth through eighth S_20_240) can respectively correspond to the same values as the DRU subcarrier indices for each 20 MHz channel defined in an 80 MHz bandwidth (first through fourth S_20_80). The DRU subcarrier indices for each 20 MHz channel within the right 80 MHz channel in the 240 MHz bandwidth (ninth through twelfth S_20_240) can respectively correspond to values obtained by adding 1024 to the DRU subcarrier indices for each 20 MHz channel defined in an 80 MHz bandwidth (first through fourth S_20_80).

[0228] For example, among two 160 MHz channels within a 320 MHz bandwidth, the DRU subcarrier indices for each 20 MHz channel within the left 160 MHz channel (first through eighth S_20_320) can respectively correspond to values obtained by subtracting 1024 from the DRU subcarrier indices for each 20 MHz channel defined in a 160 MHz bandwidth (first through eighth S_20_160). The DRU subcarrier indices for each 20 MHz channel within the right 160 MHz channel in the 320 MHz bandwidth (ninth through sixteenth S_20_320) can respectively correspond to values obtained by adding 1024 to the DRU subcarrier indices for each 20 MHz channel defined in a 160 MHz bandwidth (first through eighth S_20_160).

[0229] For example, among three 160 MHz channels within a 480 MHz bandwidth, the DRU subcarrier indices for each 20 MHz channel within the left 160 MHz channel (first S_20_480 through eighth S_20_480) can respectively correspond to values obtained by subtracting 2048 from the DRU subcarrier indices for each 20 MHz channel defined in a 160 MHz bandwidth (first S_20_160 through eighth S_20_160). The DRU subcarrier indices for each 20 MHz channel within the center 160 MHz channel in the 480 MHz bandwidth (ninth S_20_480 through sixteenth S_20_480) can respectively correspond to the same values as the DRU subcarrier indices for each 20 MHz channel defined in a 160 MHz bandwidth (first S_20_160 through eighth S_20_160). The DRU subcarrier indices for each 20 MHz channel within the right 160 MHz channel in the 480 MHz bandwidth (seventeenth S_20_480 through twenty-fourth S_20_480) can respectively correspond to values obtained by adding 2048 to the DRU subcarrier indices for each 20 MHz channel defined in a 160 MHz bandwidth (first S_20_160 through eighth S_20_160).

[0230] For example, among two 320 MHz channels within a 640 MHz bandwidth, the DRU subcarrier indices for each 20 MHz channel within the left 320 MHz channel (first S_20_640 through sixteenth S_20_640) can respectively correspond to values obtained by subtracting 2048 from the DRU subcarrier indices for each 20 MHz channel defined in a 320 MHz bandwidth (first S_20_320 through sixteenth S_20_320). The DRU subcarrier indices for each 20 MHz channel within the right 320 MHz channel in the 640 MHz bandwidth (seventeenth S_20_640 through thirty-second S_20_640) can respectively correspond to values obtained by adding 2048 to the DRU subcarrier indices for each 20 MHz channel defined in a 320 MHz bandwidth (first S_20_320 through sixteenth S_20_320).

[0231] In S1320, the first STA can transmit a PPDU to at least one second STA on a bandwidth including a first 20 MHz channel and a second 20 MHz channel.

[0232] The at least one DRU can be indicated based on RU allocation information included in a corresponding PPDU. For example, the corresponding PPDU can be a downlink PPDU (or a DL-OFDMA PPDU).

[0233] Alternatively, the at least one DRU can be indicated based on RU allocation information included in a trigger frame triggering transmission of the corresponding PPDU. For example, the corresponding PPDU can be a TB PPDU (or UL-OFDMA PPDU).

[0234] Figure 1 The method described in the examples of Figure 1 may be performed by the first apparatus 100 in Figure 13 The at least one processor 102 of the first apparatus 100 according to the examples of Figure 14 may be configured to generate a PPDU including at least one field mapped on at least one DRU, and transmit the PPDU to at least one second STA on a bandwidth including a first 20 MHz channel and a second 20 MHz channel. Further, the at least one memory 104 of the first apparatus 100 can store instructions for executing the method described in the examples of

[0235] Figure 13 is a diagram for explaining an example of a DRU tone plan based PPDU transmission method of a second STA according to the present disclosure.

[0236] In S1410, the second STA can receive, from the first STA, a PPDU including at least one field on a bandwidth including a first 20 MHz channel and a second 20 MHz channel.

[0237] In S1420, the second STA can decode the at least one field mapped on the at least one DRU.

[0238] For example, the second STA can determine the number and location of tones / subcarriers of the at least one DRU to which at least one field (e.g., data field) in the PPDU transmitted by the first STA is mapped based on RU allocation information included in the corresponding PPDU or based on RU allocation information included in a trigger frame triggering transmission of the corresponding PPDU. Based on this, the second STA can decode the at least one field mapped to the at least one DRU.

[0239] Various sizes (or number of tones / subcarriers) and locations of one or more DRUs are the same as those described in the examples of Figure 14 , and thus a redundant description is omitted.

[0240] In the examples of Figure 1 The method described in the examples of Figure 1 may be performed by the second apparatus 200 in Figure 14The at least one processor 202 of the second apparatus 200 can be configured to receive, from the first STA, a PPDU including at least one field over a bandwidth including the first 20 MHz channel and the second 20 MHz channel, and decode the at least one field mapped on the at least one DRU. Further, the at least one memory 204 of the second apparatus 200 can store instructions for performing the method described in the examples of FIG. 10 or the examples described below when executed by the at least one processor 202. Figure 13 The at least one processor 202 of the second apparatus 200 can be configured to receive, from the first STA, a PPDU including at least one field over a bandwidth including the first 20 MHz channel and the second 20 MHz channel, and decode the at least one field mapped on the at least one DRU. Further, the at least one memory 204 of the second apparatus 200 can store instructions for performing the method described in the examples of FIG. 10 or the examples described below when executed by the at least one processor 202.

[0241] Figure 14 and Figure 13 Examples of the above-described embodiments can correspond to some of various examples of the present disclosure. Hereinafter, various examples of the present disclosure including Figure 14 and Embodiment 1 Examples of the above-described embodiments can correspond to some of various examples of the present disclosure. Hereinafter, various examples of the present disclosure including

[0242] In the embodiments described below, a DRU index (i.e., DRU-n) or an nth DRU can correspond to a position in a frequency domain, or can be assigned without considering a position in a frequency domain. In the embodiments described below, for the sake of clarity of description, it is described by assuming that a relatively low DRU index includes a relatively low tone / subcarrier, but the scope of the present disclosure is not limited thereto, and the DRU index can be assigned in various ways to distinguish different DRUs.

[0243] Further, in the following description, a subcarrier index assumes that an index of a DC subcarrier is 0 and corresponds to a position in a frequency domain, and the term subcarrier can be replaced with tone.

[0244] Embodiment 1-1

[0245] In this embodiment, various examples of subcarrier indices of a 26-tone DRU and a pilot subcarrier related thereto are described.

[0246] Embodiment 1-2

[0247] This embodiment relates to a method of assigning one subcarrier to each of nine 26-tone DRUs in order from a lowest available subcarrier to a highest available subcarrier for each 20 MHz channel in a lower 20 MHz channel and an upper 20 MHz channel within a 40 MHz bandwidth.

[0248] For example, for the lower 20 MHz channel, each of the nine 26-tone DRUs can include the following subcarriers:

[0249] 26-tone DRU-1 : -243, -233, -223, -214, -204, -194, -182, -173, -163, -153, -143, -133, -123, -113, -102, -93, -83, -73, -63, -52, -42, -32, -22, -13

[0250] 26-tone DRU-2: -242, -232, -222, -213, -203, -193, -181, -172, -162, -152, -142, -132, -122, -112, -101, -92, -82, -72, -62, -51, -41, -31, -21, -12

[0251] 26-tone DRU-3: -241, -231, -221, -211, -202, -192, -180, -171, -161, -151, -141, -131, -121, -111, -100, -91, -81, -71, -61, -49, -40, -30, -20, -11

[0252] 26-tone DRU-4: -240, -230, -220, -210, -201, -189, -179, -169, -160, -150, -140, -129, -120, -109, -99, -89, -80, -70, -60, -48, -39, -29, -19, -9

[0253] 26-tone DRU-5: -239, -229, -219, -209, -200, -188, -178, -168, -159, -149, -139, -128, -119, -108, -98, -88, -79, -69, -59, -47, -38, -28, -18, -8

[0254] 26-tone DRU-6: -237, -228, -218, -208, -199, -187, -177, -167, -157, -148, -138, -127, -118, -107, -97, -87, -77, -68, -58, -46, -37, -27, -17, -7

[0255] 26-tone DRU-7: -236, -227, -217, -207, -197, -186, -176, -166, -156, -147, -136, -126, -117, -106, -96, -86, -76, -67, -55, -45, -35, -26, -16, -6

[0256] 26-tone DRU-8: -235, -226, -216, -206, -196, -185, -175, -165, -155, -146, -135, -125, -115, -105, -95, -85, -75, -66, -54, -44, -34, -25, -15, -5

[0257] 26-tone DRU-9: -234, -225, -215, -205, -195, -183, -174, -164, -154, -145, -134, -124, -114, -103, -94, -84, -74, -65, -53, -43, -33, -23, -14, -4

[0258] For example, for a higher 20 MHz channel, each of the nine 26-tone DRUs can include the following subcarriers:

[0259] 26-tone DRU-1: 4, 14, 23, 33, 43, 53, 65, 74, 84, 94, 103, 114, 124, 134, 145, 154, 164, 174, 183, 195, 205, 215, 225, 234

[0260] 26-tone DRU-2: 5, 15, 25, 34, 44, 54, 66, 75, 85, 95, 105, 115, 125, 135, 146, 155, 165, 175, 185, 196, 206, 216, 226, 235

[0261] 26-tone DRU-3: 6, 16, 26, 35, 45, 55, 67, 76, 86, 96, 106, 117, 126, 136, 147, 156, 166, 176, 186, 197, 207, 217, 227, 236

[0262] 26-tone DRU-4: 7, 17, 27, 37, 46, 58, 68, 77, 87, 97, 107, 118, 127, 138, 148, 157, 167, 177, 187, 199, 208, 218, 228, 237

[0263] 26-tone DRU-5: 8, 18, 28, 38, 47, 59, 69, 79, 88, 98, 108, 119, 128, 139, 149, 159, 168, 178, 188, 200, 209, 219, 229, 239

[0264] 26-tone DRU-6: 9, 19, 29, 39, 48, 60, 70, 80, 89, 99, 109, 120, 129, 140, 150, 160, 169, 179, 189, 201, 210, 220, 230, 240

[0265] 26-tone DRU-7: 11, 20, 30, 40, 49, 61, 71, 81, 91, 100, 111, 121, 131, 141, 151, 161, 171, 180, 192, 202, 211, 221, 231, 241

[0266] 26-tone DRU-8: 12, 21, 31, 41, 51, 62, 72, 82, 92, 101, 112, 122, 132, 142, 152, 162, 172, 181, 193, 203, 213, 222, 232, 242

[0267] 26-tone DRU-9: 13, 22, 32, 42, 52, 63, 73, 83, 93, 102, 113, 123, 133, 143, 153, 163, 173, 182, 194, 204, 214, 223, 233, 243

[0268] In addition to the subcarrier indices included in the 26-tone DRUs in the above examples, the subcarrier indices can be assigned to the 26-tone DRUs in other ways. For example, while the above examples assume that the available subcarriers exclude the guard subcarriers, the null subcarriers, the DC subcarrier, and the pilot subcarrier, the subcarrier indices included in each 26-tone DRU can also be defined by assuming that the available subcarriers include one or more of the guard subcarriers, the null subcarriers, the DC subcarrier, or the pilot subcarrier.

[0269] Additionally or alternatively, for a first bandwidth and / or a first BSS color (COLOR), the 26-tone DRUs including the subcarrier indices according to the above examples can be applied, and for a second bandwidth and / or a second BSS color, the 26-tone DRUs including the subcarrier indices in another way can be applied.

[0270] Embodiment 2

[0271] Implementation 1-2 describes a method for defining the pilot subcarriers of the 26-tone DRUs (based on the method of implementation 1-1).

[0272] In particular, a method for allocating 18 pilot subcarriers within each 20MHz channel within a 40MHz or greater bandwidth to nine 26-tone DRUs is proposed. In this regard, for each DRU, two pilot subcarriers can be selected and used from among the pilot subcarriers defined in a 26-tone RRU or a 52-tone RRU (see, e.g., Tables 4 and 5). At this point, the pilot subcarriers can not overlap with each other among the DRUs.

[0273] For example, for the lower 20MHz channel within a 40MHz bandwidth, the 18 pilot subcarrier indices {-238, -224, -212, -198, -184, -170, -158, -144, -130, -116, -104, -90, -78, -64, -50, -36, -24, -10} can be allocated for the nine 26-tone DRUs. In addition, for the upper 20MHz channel within a 40MHz bandwidth, the 18 pilot subcarrier indices {10, 24, 36, 50, 64, 78, 90, 104, 116, 130, 144, 158, 170, 184, 198, 212, 224, 238} can be allocated for the nine 26-tone DRUs.

[0274] For each of the lower 20MHz channel and / or the upper 20MHz channel, the allocation / definition of the pilot subcarriers for the 26-tone DRUs can be based on one or more of the following methods:

[0275] (Method 1)

[0276] Assuming that a mapping relationship between the existing RRU indices and the newly defined DRU indices is predefined, the pilot subcarriers of the DRUs can be allocated / defined based on the pilot subcarriers of the RRUs that are mapped to the DRUs.

[0277] For example, by defining an additional subfield (e.g., information indicating whether it is a DRU, etc.) in an existing RU allocation subfield (e.g., included in a PPDU / trigger frame, etc.), the DRU can be indicated by reusing an existing signaling method. In this case, the DRU can be defined to use the same pilot subcarriers as the pilot subcarriers of the RRU mapped by the above mapping relationship.

[0278] As a specific example, if an xth26-tone RRU in a 40MHz channel is mapped to a yth26-tone DRU in the lower 20MHz channel / upper 20MHz channel, the pilot subcarrier indices defined for the xth26-tone RRU can be allocated to the yth26-tone DRU (see, e.g., the pilot subcarrier indices in the 40MHz bandwidth in Table 4).

[0279] (Method 2)

[0280] For 9 26-tone DRUs within a 20MHz channel, pilot subcarriers with a fixed spacing can be allocated / defined for each 26-tone DRU.

[0281] For example, since there are 18 pilot subcarriers within each of the 20MHz channels included in the 40MHz bandwidth, two pilot subcarriers spaced by 9 pilot subcarriers can be allocated to each DRU. As a specific example, when the indices of the 18 pilot subcarriers within a 20MHz channel are set / defined as pilot subcarrier indices 1 through 18, pilot subcarrier indices {1, 10} can be allocated to 26-tone DRU-1, pilot subcarrier indices {2, 11} can be allocated to 26-tone DRU-2,..., and pilot subcarrier indices {9, 18} can be allocated to 26-tone DRU-9.

[0282] (Method 3)

[0283] Considering a case where another size of DRU (e.g., 52-tone DRU, 106-tone DRU) is configured / generated by combining DRUs of a smaller size (e.g., 26-tone DRU, 52-tone DRU), pilot subcarriers of each 26-tone DRU within a 20MHz channel can be allocated / defined.

[0284] For example, for the remaining 8 26-tone DRUs excluding the 26-tone DRU (e.g., 26-tone DRU-5) not used to generate a 52-tone DRU, among the 18 pilot subcarriers, subcarriers used as pilot subcarriers in a 106-tone RRU can be allocated as pilots for each 26-tone DRU, and subcarriers used as pilot subcarriers in a 26-tone RRU and / or a 52-tone RRU but used as data subcarriers in a 106-tone RRU can be allocated as pilots for each 26-tone DRU. In this case, among the 18 pilot subcarriers, the remaining pilot subcarriers not allocated to the 8 26-tone DRUs can be allocated to the 26-tone DRU not used to generate a 52-tone DRU.

[0285] Specifically, for each 20MHz channel within a 40MHz bandwidth, pilot subcarrier indices for two predefined 106-tone (i.e., 106-tone RRU-1, 106-tone RRU-2) are defined / allocated (e.g., see Table 6 for pilot subcarrier indices in a 40MHz bandwidth).

[0286] In this case, for 26-tone DRU-1 to 26-tone DRU-4, the subcarriers used as pilot subcarriers in the 106-tone RRU-1 can be sequentially assigned as pilots one by one, and the subcarriers used as pilot subcarriers in the 26-tone RRU and / or 52-tone RRU but used as data subcarriers in the 106-tone RRU-2 can be sequentially assigned as pilots one by one. Further, for 26-tone DRU-6 to 26-tone DRU-9, the subcarriers used as pilot subcarriers in the 106-tone RRU-2 can be sequentially assigned as pilots one by one, and the subcarriers used as pilot subcarriers in the 26-tone RRU and / or 52-tone RRU but used as data subcarriers in the 106-tone RRU-1 can be sequentially assigned as pilots one by one. The remaining pilot subcarriers (i.e., those not assigned to 26-tone DRU-1 to 26-tone DRU-4 and 26-tone DRU-6 to 26-tone DRU-9 among the 18 pilot subcarriers present within the 20 MHz channel) can be assigned to 26-tone DRU-5.

[0287] As a specific example, in the case where a first pilot index set {-238, -212, -170, -144} is defined for a predefined 106-tone RRU-1A and a second pilot index set {-104, -78, -36, -10} is defined for a predefined 106-tone RRU-2A with respect to a lower 20 MHz channel within a 40 MHz bandwidth (see, e.g., Table 6), pilot subcarriers for 9 26-tone DRUs (i.e., 26-tone DRU-1A to 26-tone DRU-9A) can be defined / assigned.

[0288] With respect to the 26-tone DRU-1A through 26-tone DRU-4A, subcarrier indices included in the set of pilot indices {-238, -224, -212, -198, -184, -170, -158, -144, -130, -116, -104, -90, -78, -64, -50, -36, -24, -10} predefined for 26-tone RRU / 52-tone RRU and included in the first set of pilot indices (e.g., subcarrier indices {-238, -212, -170, -144}) can be individually assigned as pilot subcarriers. In addition, with respect to the 26-tone DRU-1A through 26-tone DRU-4A, subcarrier indices included in the set of pilot indices {-238, -224, -212, -198, -184, -170, -158, -144, -130, -116, -104, -90, -78, -64, -50, -36, -24, -10} predefined for 26-tone RRU / 52-tone RRU and used as data subcarriers for 106-tone RRU-2A (and in addition, not included in the second set of pilot indices) (e.g., subcarrier indices {-90, -64, -50, -24}) can be individually assigned as pilot subcarriers.

[0289] With respect to the 26-tone DRU-6A through 26-tone DRU-9A, subcarrier indices included in the set of pilot indices {-238, -224, -212, -198, -184, -170, -158, -144, -130, -116, -104, -90, -78, -64, -50, -36, -24, -10} predefined for 26-tone RRU / 52-tone RRU and included in the second set of pilot indices (e.g., subcarrier indices {-104, -78, -36, -10}) can be individually assigned as pilot subcarriers. In addition, with respect to the 26-tone DRU-6A through 26-tone DRU-9A, subcarrier indices included in the set of pilot indices {-238, -224, -212, -198, -184, -170, -158, -144, -130, -116, -104, -90, -78, -64, -50, -36, -24, -10} predefined for 26-tone RRU / 52-tone RRU and used as data subcarriers for 106-tone RRU-1A (and in addition, not included in the second set of pilot indices) (e.g., subcarrier indices {-224, -198, -184, -158}) can be individually assigned as pilot subcarriers.

[0290] For the 26-tone DRU-5A, the remaining subcarrier indices (e.g., subcarrier indices {-130, -116}) included in the pre-defined pilot index set {-238, -224, -212, -198, -184, -170, -158, -144, -130, -116, -104, -90, -78, -64, -50, -36, -24, -10} for 26-tone RRU / 52-tone RRU and not assigned can be assigned as pilot subcarriers.

[0291] As a specific example, for the upper 20 MHz channel within a 40 MHz bandwidth, when a first pilot index set {10, 36, 78, 104} is defined for the pre-defined 106-tone RRU-1B and a second pilot index set {144, 170, 212, 238} is defined for the pre-defined 106-tone RRU-2B (see, e.g., Table 6), pilot subcarriers for nine 26-tone DRUs (i.e., 26-tone DRU-1B to 26-tone DRU-9B) can be defined / assigned.

[0292] For the 26-tone DRU-1B to 26-tone DRU-4B, the subcarrier indices (e.g., subcarrier indices {10, 36, 78, 104}) included in the pre-defined pilot index set {10, 24, 36, 50, 64, 78, 90, 104, 116, 130, 144, 158, 170, 184, 198, 212, 224, 238} for 26-tone RRU / 52-tone RRU and in the first pilot index set can be assigned as pilot subcarriers one by one. In addition, for the 26-tone DRU-1B to 26-tone DRU-4B, the subcarrier indices (e.g., subcarrier indices {158, 184, 198, 224}) included in the pre-defined pilot index set {10, 24, 36, 50, 64, 78, 90, 104, 116, 130, 144, 158, 170, 184, 198, 212, 224, 238} for 26-tone RRU / 52-tone RRU and used as data subcarriers for the 106-tone RRU-2B (furthermore, not included in the second pilot index set) can be assigned as pilot subcarriers one by one.

[0293] For the 26-tone DRU-6B to 26-tone DRU-9B, subcarrier indices included in the predefined pilot index group {10, 24, 36, 50, 64, 78, 90, 104, 116, 130, 144, 158, 170, 184, 198, 212, 224, 238} for the 26-tone RRU / 52-tone RRU and included in the second pilot index group (e.g., subcarrier indices {144, 170, 212, 238}) can be assigned as pilot subcarriers one by one. In addition, for the 26-tone DRU-6B to 26-tone DRU-9B, subcarrier indices included in the predefined pilot index group {10, 24, 36, 50, 64, 78, 90, 104, 116, 130, 144, 158, 170, 184, 198, 212, 224, 238} for the 26-tone RRU / 52-tone RRU and used as data subcarriers of the 106-tone RRU-1B (in addition, not included in the first pilot index group) (e.g., subcarrier indices {24, 50, 64, 90}) can be assigned as pilot subcarriers one by one.

[0294] For the 26-tone DRU-5B, remaining subcarrier indices included in the predefined pilot index group {10, 24, 36, 50, 64, 78, 90, 104, 116, 130, 144, 158, 170, 184, 198, 212, 224, 238} for the 26-tone RRU / 52-tone RRU and not assigned (e.g., subcarrier indices {116, 130}) can be assigned as pilot subcarriers.

[0295] Additionally or alternatively, a method of selecting and assigning pilot subcarriers having less overlap or no overlap with STF subcarriers for DRUs having less overlap or no overlap with the STF subcarriers can be applied.

[0296] Embodiment 2-1

[0297] In this embodiment, various examples of configuring subcarrier indices of a 52-tone DRU and pilot subcarriers associated therewith will be described.

[0298] Embodiment 2-2

[0299] Embodiment 2-1 is a method of configuring one 52-tone DRU with a combination of two 26-tone DRUs for each 20MHz channel included in a 40MHz bandwidth.

[0300] For example, four 52-tone DRUs can be defined within each 20MHz channel included in the 40MHz bandwidth, and one 52-tone DRU can correspond to a combination of two 26-tone DRUs. For example, two 26-tone DRUs can correspond to two of the nine 26-tone DRUs defined in Embodiment 1 described above. If 26-tone DRU-5 is not used as a basis for a 52-tone DRU, then a combination of two 26-tone DRUs among the eight 26-tone DRUs can correspond to one 52-tone DRU.

[0301] The two 26-tone DRUs corresponding to one 52-tone DRU can correspond to those DRUs spaced apart as far as possible in the frequency domain and distributing subcarriers uniformly to the 52-tone DRU. The four 52-tone DRUs can be defined as follows.

[0302] 52-tone DRU-1: 26-tone DRU-1 and 26-tone DRU-6

[0303] 52-tone DRU-2: 26-tone DRU-2 and 26-tone DRU-7

[0304] 52-tone DRU-3: 26-tone DRU-3 and 26-tone DRU-8

[0305] 52-tone DRU-4: 26-tone DRU-4 and 26-tone DRU-9

[0306] Here, each 52-tone DRU can be defined as a set of subcarrier indices corresponding to the 26-tone DRU indices defined in Embodiment 1.

[0307] For example, when 26-tone DRUs 1 through 9 in the lower 20MHz channel are referred to as 26-tone DRUs 1A through 9A, four 52-tone DRUs for the lower 20MHz channel can be defined as follows.

[0308] 52-tone DRU-1A: 26-tone DRU-1A and 26-tone DRU-6A

[0309] 52-tone DRU-2A: 26-tone DRU-2A and 26-tone DRU-7A

[0310] 52-tone DRU-3A: 26-tone DRU-3A and 26-tone DRU-8A

[0311] 52-tone DRU-4A: 26-tone DRU-4A and 26-tone DRU-9A

[0312] For example, when the 26-tone DRUs-1 through 26-tone DRUs-9 within the higher 20 MHz channel are referred to as 26-tone DRUs-1B through 26-tone DRUs-9B, the four 52-tone DRUs for the higher 20 MHz channel can be defined as follows.

[0313] 52-tone DRU-1B: 26-tone DRU-1B and 26-tone DRU-6B

[0314] 52-tone DRU-2B: 26-tone DRU-2B and 26-tone DRU-7B

[0315] 52-tone DRU-3B: 26-tone DRU-3B and 26-tone DRU-8B

[0316] 52-tone DRU-4B: 26-tone DRU-4B and 26-tone DRU-9B

[0317] Embodiment 3

[0318] Embodiment 2-2 relates to a method for defining pilot subcarriers for 52-tone DRUs (based on the method of Embodiment 2-1).

[0319] In particular, with respect to the four 52-tone DRUs for each 20 MHz channel within the 40 MHz bandwidth, four pilot subcarriers can be allocated / defined for each DRU.

[0320] In this regard, for each DRU, four pilot subcarriers can be selected and used among the pilot subcarriers defined in the 26-tone RRU or 52-tone RRU (see, e.g., Tables 4, 5). In this case, the pilot subcarriers can not overlap among the corresponding DRUs.

[0321] In particular, for the lower 20 MHz channel within the 40 MHz bandwidth, the four 52-tone DRUs can be allocated the 16 pilot subcarrier indices {-238, -224, -212, -198, -184, -170, -158, -144, -104, -90, -78, -64, -50, -36, -24, -10}. Additionally, for the higher 20 MHz channel within the 40 MHz bandwidth, the four 52-tone DRUs can be allocated the 16 pilot subcarrier indices {10, 24, 36, 50, 64, 78, 90, 104, 144, 158, 170, 184, 198, 212, 224, 238}.

[0322] For each of the lower 20MHz channel and / or the upper 20MHz channel, the allocation / definition of the pilot subcarriers of the 52-tone DRU can be based on one or more of the following examples:

[0323] For example, the pilot subcarriers of the 26-tone DRU used in the combination for configuring the 52-tone DRU can be used as the pilot subcarriers of the corresponding 52-tone DRU.

[0324] As another example, similar to the case of the 26-tone DRU, assuming that a mapping relationship between the existing RRU indices and the newly defined DRU indices is predefined, the pilot subcarriers of the DRU can be allocated / defined based on the pilot subcarriers of the RRU mapped to the DRU. As one example, the DRU can be defined to use the same pilot subcarriers as the pilot subcarriers of the RRU mapped by the above mapping relationship.

[0325] Specifically, if the xth 52-tone RRU in the 40MHz channel is mapped to the yth 52-tone DRU in the lower 20MHz channel / upper 20MHz channel, the pilot subcarrier indices defined for the xth 52-tone RRU (see, for example, the pilot subcarrier indices in the 40MHz bandwidth of Table 5) can be allocated to the yth 52-tone DRU.

[0326] As yet another example, the following method can be applied: select and allocate pilot subcarriers that do not overlap or have less overlap with the STF subcarriers for DRUs that do not overlap or have less overlap with the STF subcarriers.

[0327] Embodiment 3-1

[0328] In this embodiment, various examples of subcarrier indices of a 106-tone DRU and pilot subcarriers associated therewith will be described.

[0329] Embodiment 3-2

[0330] Embodiment 3-1 is a method of configuring one 106-tone DRU with a combination of two 52-tone DRUs and two additional subcarriers for each 20MHz channel included in a 40MHz bandwidth.

[0331] For example, two 106-tone DRUs can be defined within each 20MHz channel included in the 40MHz bandwidth. The subcarrier indices included in one 106-tone DRU can correspond to the set of subcarrier indices included in two 52-tone DRUs and the indices of two additional subcarriers. Furthermore, the subcarriers included in each 106-tone DRU can be defined to be distributed as much as possible.

[0332] Two 106-tone DRUs can be defined as follows:

[0333] 106-tone DRU-1: a combination of 52-tone DRU-1, 52-tone DRU-3, and two additional subcarriers

[0334] 106-tone DRU-2: a combination of 52-tone DRU-2, 52-tone DRU-4, and two additional subcarriers

[0335] Here, each 106-tone DRU can be defined as a set of subcarrier indices corresponding to the 52-tone DRU indices defined in Embodiment 2.

[0336] For example, when 52-tone DRUs 1 through 4 in the lower 20 MHz channel are referred to as 52-tone DRUs 1A through 4A, two 106-tone DRUs for the lower 20 MHz channel can be defined as follows.

[0337] 106-tone DRU-1A: a combination of 52-tone DRU-1A, 52-tone DRU-3A, and two additional subcarriers

[0338] 106-tone DRU-2A: a combination of 52-tone DRU-2A, 52-tone DRU-4A, and two additional subcarriers

[0339] For example, when 52-tone DRUs 1 through 4 in the lower 20 MHz channel are referred to as 52-tone DRUs 1A through 4A, two 106-tone DRUs for the lower 20 MHz channel can be defined as follows.

[0340] 106-tone DRU-1B: a combination of 52-tone DRU-1B, 52-tone DRU-3B, and two additional subcarriers

[0341] 106-tone DRU-2B: a combination of 52-tone DRU-2B, 52-tone DRU-4B, and two additional subcarriers

[0342] In this regard, the two additional subcarriers included in the 106-tone DRU can be two of the four empty subcarriers not used in the 26-tone DRU and the 52-tone DRU. That is, some of the empty subcarriers in the 26-tone DRU and the 52-tone DRU can be included in the available subcarriers for the 106-tone DRU. Further, the indices of the two additional subcarriers included in different 106-tone DRUs can not overlap each other.

[0343] As a detailed example, the two additional subcarriers included in the 106-tone DRU defined within the lower 20 MHz channel can be two of the four null subcarriers {-191, -190, -57, -56}. Also, the two additional subcarriers included in the 106-tone DRU defined within the upper 20 MHz channel can be two of the other four null subcarriers {56, 57, 190, 191}.

[0344] Additionally or alternatively, assuming that the mapping relationship between the existing RRU index and the newly defined DRU index is predefined, if a certain 106-tone RRU index includes an additional subcarrier index (i.e., a null subcarrier in the 26-tone RRU / DRU or the 52-tone RRU / DRU), it can be defined that the 106-tone DRU index mapped to the 106-tone RRU index includes the same additional subcarrier index.

[0345] Additionally or alternatively, two different combinations of the four null subcarriers can be selected so as not to overlap in different 106-tone DRUs. For example, the combination of odd-numbered subcarriers and even-numbered subcarriers among the above-described four null subcarriers can be defined to be included in different 106-tone DRUs.

[0346] Embodiment 4

[0347] Embodiment 3-2 relates to a method for defining pilot subcarriers for 106-tone DRUs (based on the method of Embodiment 3-1).

[0348] Specifically, with respect to the two 106-tone DRUs for each 20 MHz channel within the 40 MHz bandwidth, four pilot subcarriers can be allocated / defined for each DRU.

[0349] In this regard, for each DRU, eight pilot subcarriers can be selected from among the pilot subcarriers defined in the 26-tone RRU or the 52-tone RRU (see, for example, Tables 4 and 5), of which four can be used as data subcarriers and the remaining four can be used as pilot subcarriers. In this case, when the pilot subcarriers are selected, it can be preferable to select the four pilot subcarriers and the four data subcarriers defined in the 106-tone RRU.

[0350] Specifically, for the lower 20 MHz channel within the 40 MHz bandwidth, 8 subcarrier indices can be selected from 16 pilot subcarrier indices {-238, -224, -212, -198, - 184, -170, -158, -144, -104, -90, -78, -64, -50, -36, -24, -10}. At this time, for the existing 106-tone RRU, the predefined pilot subcarrier indices are {-238, -212, -170, -144, -104, -78, -36, -10} (see, for example, Table 6), and the data subcarrier indices can be {-224, -198, -184, -158, -90, -64, -50, -24}.

[0351] In addition, for the higher 20 MHz channel within the 40 MHz bandwidth, 8 subcarrier indices can be selected from 16 pilot subcarrier indices {10, 24, 36, 50, 64, 78, 90, 104, 144, 158, 170, 184, 198, 212, 224, 238}. At this time, for the existing 106-tone RRU, the predefined pilot subcarrier indices can be {10, 36, 78, 104, 144, 170, 212, 238} (see, for example, Table 6), and the data subcarrier indices can be {24, 50, 64, 90, 158, 184, 198, 224}.

[0352] For each of the lower 20 MHz channel and / or the higher 20 MHz channel, the allocation / definition of the pilot subcarriers for the 106-tone DRU can be based on one or more of the following examples:

[0353] For example, among the pilot subcarriers of the 52-tone DRU constituting the 106-tone DRU, the subcarriers defined as data subcarriers in the existing 106-tone RRU can be converted to data subcarriers for the 106-tone DRU, and the subcarriers defined as pilot subcarriers in the existing 106-tone RRU can be used as pilot subcarriers for the 106-tone DRU.

[0354] As another example, assuming that a mapping relationship between existing RRU indices and newly defined DRU indices is predefined, among the subcarriers used in the 106-tone RRU mapped to the 106-tone DRU, the subcarriers that are pilot subcarriers in the 26-tone RRU or the 52-tone RRU but are used as data subcarriers can be included / as data subcarriers for the corresponding 106-tone DRU. In addition, the pilot subcarriers used in the 106-tone RRU mapped to the 106-tone DRU can be pilot subcarriers for the 106-tone DRU.

[0355] As still another example, for a DRU that does not overlap or has less overlap with the STF subcarriers, the pilot subcarriers defined in the 26-tone RRU and / or the 52-tone RRU that overlap with the STF subcarriers can be selected and allocated such that four of them are used as data subcarriers and the rest are used as pilot subcarriers. In this case, when the pilot subcarriers are selected, the four pilot subcarriers defined in the 106-tone RRU and the four data subcarriers can be preferably selected.

[0356] According to the DRU tone plan defined in the various examples of the present disclosure described above, DRUs of the same / different sizes can be allocated to different STAs.

[0357] For example, when a specific RU index is indicated by an RU allocation field included in a SIG (e.g., U-SIG and / or UHR-SIG) field in a DL OFDMA transmission, the STA receiving the PPDU can interpret that a data field within the corresponding PPDU is mapped on subcarriers included in a DRU corresponding to the indicated RU index, and can decode the data field accordingly. Alternatively, when a specific RU index is indicated by an RU allocation subfield within a trigger frame, the STA receiving the trigger frame can transmit a TB PPDU to which a data field is mapped on subcarriers included in a DRU corresponding to the indicated RU index. Here, the DRU corresponding to the indicated RU index can be determined based on a mapping rule between the RRU and the DRU.

[0358] Embodiment 5

[0359] Instead of defining the 52-tone DRU in Embodiment 2 above to include the subcarriers of the two 26-tone DRUs in a fixed combination, a method of dynamically performing signaling to include the subcarriers of the two 26-tone DRUs in any combination can be applied. Here, the 26-tone DRU can be the DRU defined in Embodiment 1, or can be a DRU defined in another manner.

[0360] Additionally or alternatively, instead of predefining the 106-tone DRU in Embodiment 3 to include a fixed combination of two 52-tone DRUs (or a fixed combination of four 26-tone DRUs), a dynamic signaling scheme can be applied to include subcarriers of any combination of two 52-tone DRUs (or any combination of four 26-tone DRUs). Here, the 26-tone DRU can be defined as in Embodiment 1, or can be defined in another way. In addition, the combination of two additional subcarriers included in the 106-tone DRU can be defined as described in Embodiment 3.

[0361] Even when the dynamic signaling scheme as described above is applied, the combination of the pilot subcarriers of the 26-tone DRU, the pilot subcarriers of the 52-tone DRU, and the null subcarriers, pilot subcarriers, and additional data subcarriers (e.g., four additional data subcarriers) of the 106-tone DRU can be configured based on Embodiment 1, Embodiment 2, and Embodiment 3.

[0362] When the per-symbol shifted DRU is applied to obtain a diversity gain (e.g., when the subcarrier index included in a specific DRU index in a first symbol is different from the subcarrier index included in the same specific DRU index in a second symbol), it can be useful to apply a method for dynamically signaling the subcarriers included in the 52-tone DRU and / or the 106-tone DRU in this way.

[0363] When the DRU index allocated to the STA is signaled by using the existing RU allocation information (e.g., the SIG (e.g., U-SIG and / or UHR-SIG) field for the DL OFDMA PPDU), a predefined mapping rule between the 26-tone RRU index and the 26-tone DRU index can be applied. For example, the mapping rule can map the DRU index-1 including the lowest subcarrier to the RRU-1 including the lowest subcarrier, and map the DRU including the next lowest subcarrier in ascending order of the RRU index. When the RRC to DRU mapping rule is defined in this way, a plurality of 26-tone RRU indexes can be indicated to the STA to allocate the 52-tone DRU or the 106-tone DRU, and thus, the STA can determine the subcarriers included in the 26-tone DRU included in the 52-tone DRU or the 106-tone DRU allocated to it.

[0364] For example, 2 / 4 26-tone RRU indices corresponding to 2 / 4 26-tone DRUs corresponding to 52-tone DRU / 106-tone DRU can be indicated to one STA through RU allocation information, and STA ID values included in user information (e.g., user field of U-SIG / UHR-SIG field of DL OFDMA PPDU (e.g., MU PPDU) or UHR variant user information field of trigger frame) corresponding to such 2 / 4 26-tone RRUs can be set to the same values as the ID of the corresponding STA. In addition, information indicating that a DRU is allocated and / or information indicating whether it is the last index among a plurality of 26-tone RRU indices corresponding to a DRU allocated to the corresponding STA can be defined within the user information (e.g., user field of U-SIG / UHR-SIG field of DL OFDMA PPDU (e.g., MU PPDU) or UHR variant user information field of trigger frame).

[0365] Embodiment 6

[0366] As in Embodiment 2 described above, a predefined 52-tone DRU includes subcarriers of two 26-tone DRUs in a fixed combination, and as in Embodiment 3 described above, a predefined 106-tone DRU includes subcarriers of two 52-tone DRUs (or four 26-tone DRUs in a fixed combination), but the DRU index can be generalized and mapped to each RRU index, thereby flexibly configuring 26-tone DRUs / 52-tone DRUs corresponding to a specific 52-tone DRU / 106-tone DRU.

[0367] For example, 26-tone DRU-a / b / c / d / e / f / g / h / i can be defined to correspond to 26-tone DRU-1 / 2 / 3 / 4 / 5 / 6 / 7 / 8 / 9 in an arbitrary manner (e.g., indices a to i and indices 1 to 9 one-to-one, but the numerical index corresponding to each alphabetical index is determined in ascending order or in an arbitrary order). Here, for the position of the subcarriers included in the 26-tone DRU, the example of Embodiment 1 can be applied or another method can be applied. Based on this, 52-tone DRU-a / b / c / d and 106-tone-DRU-a / b corresponding to the combination of lower size DRU indices can be defined as in the following examples.

[0368] 52-tone DRU-a: 26-tone DRU-a and 26-tone DRU-f

[0369] 52-tone DRU-b: 26-tone DRU-b and 26-tone DRU-g

[0370] 52-tone DRU-a: 26-tone DRU-a and 26-tone DRU-c

[0371] 52-tone DRU-d = 26-tone DRU-d and 26-tone DRU-i

[0372] 106-tone DRU-a: 52-tone DRU-a, 52-tone DRU-c, and two additional subcarriers

[0373] 106-tone DRU-b: 52-tone DRU-b, 52-tone DRU-d, and two additional subcarriers

[0374] Here, the two additional subcarriers for the 106-tone DRU can be defined as described in embodiment 3.

[0375] Additionally or alternatively, a gap between a plurality of lower size DRU indices corresponding to one higher size DRU index can be used. The value of the gap can be explicitly signaled to the STAs or can be implicitly signaled based on other information (e.g., bandwidth information, BSS color information, etc.) without separate signaling. For example, 52-tone DRU and 106-tone DRU can include subcarriers of lower size DRU as follows.

[0376] 52-tone DRU-a: 26-tone DRU-a, 26-tone DRU- (a + gap)

[0377] 52-tone DRU-b: 26-tone DRU-b, 26-tone DRU- (b + gap)

[0378] 52-tone DRU-c: 26-tone DRU-c, 26-tone DRU- (c + gap)

[0379] 52-tone DRU-d: 26-tone DRU-d, 26-tone DRU- (d + gap)

[0380] 106-tone DRU-a: 52-tone DRU-a, 52-tone DRU- (a + gap), and two additional subcarriers

[0381] 106-tone DRU-b: 52-tone DRU-b, 52-tone DRU- (b + gap), and two additional subcarriers

[0382] Here, the two additional subcarriers for the 106-tone DRU can be defined as described in embodiment 3.

[0383] In the above examples, the order of the letter indices of the DRUs and the order of the locations in the frequency domain can be unrelated. Also, even when the letter indices of the DRUs of different sizes are the same, it does not mean that the order within the same size DRU indices is the same.

[0384] In the above examples, the value of the gap can have the same / different values for each DRU size. For example, the value of the gap can have independent values for each DRU size, or can have associated values.

[0385] Embodiment 6-1

[0386] This embodiment relates to the subcarrier indices of each DRU when applying the DRU in each 20MHz of a bandwidth greater than 40MHz (e.g., 80MHz or greater bandwidth).

[0387] In the following examples, the set of subcarrier indices included in each DRU of one or more DRUs for x MHz of a y MHz bandwidth can be denoted as S_x_y.

[0388] For example, it can be assumed that the first S_20_40 corresponds to the subcarrier indices included in the various sizes of DRUs of the lower 20MHz channel of the 40MHz bandwidth in the examples described in Embodiments 1 to 5 above. In addition, it can be assumed that the second S_20_40 corresponds to the subcarrier indices included in the various sizes of DRUs of the upper 20MHz channel of the 40MHz bandwidth in the examples described in Embodiments 1 to 5 above.

[0389] Embodiment 6-2

[0390] The subcarrier indices at the specific 20MHz of the 80MHz bandwidth (S_20_80) can be defined as follows.

[0391] The subcarrier indices of each 20MHz within the first 40MHz (first S_20_80 and second S_20_80): the DRU subcarrier indices of each 20MHz defined in the preceding 40MHz (first S_20_40 and second S_20_40) - 256

[0392] The subcarrier indices of each 20MHz within the second 40MHz (third S_20_80 and fourth S_20_80): the DRU subcarrier indices of each 20MHz defined in the preceding 40MHz (first S_20_40 and second S_20_40) + 256

[0393] For example, it can be expressed as follows:

[0394] First S_20_80 = First S_20_40 - 256;

[0395] Second S_20_80 = Second S_20_40 - 256;

[0396] Third S_20_80 = First S_20_40 + 256; and

[0397] Fourth S_20_80 = Second S_20_40 + 256.

[0398] Embodiment 6-3

[0399] The subcarrier index (S_20_160) for a particular 20 MHz within a 160 MHz bandwidth can be defined as follows:

[0400] The subcarrier index (first through fourth S_20_160) for each 20 MHz within a first 80 MHz: the DRU subcarrier index (first through fourth S_20_80) defined above for each 20 MHz in the 80 MHz - 512

[0401] The subcarrier index (fifth through eighth S_20_160) for each 20 MHz within a second 80 MHz: the DRU subcarrier index (first through fourth S_20_80) defined above for each 20 MHz in the 80 MHz + 512

[0402] For example, it can be expressed as follows:

[0403] First S_20_160 = First S_20_80 - 512;

[0404] Second S_20_160 = Second S_20_80 - 512;

[0405] Third S_20_160 = Third S_20_80 - 512;

[0406] Fourth S_20_160 = Fourth S_20_80 - 512;

[0407] Fifth S_20_160 = First S_20_80 + 512;

[0408] Sixth S_20_160 = Second S_20_80 + 512;

[0409] Seventh S_20_160 = Third S_20_80 + 512; and

[0410] Eighth S_20_160 = Fourth S_20_80 + 512.

[0411] Embodiment 6-4

[0412] The subcarrier index at the specific 20 MHz of the 240 MHz bandwidth (S_20_240) can be defined as follows.

[0413] The subcarrier index for each 20 MHz within the first 80 MHz (first through fourth S_20_160): The DRU subcarrier index for each 20 MHz defined in the above 80 MHz (first through fourth S_20_80) - 1024

[0414] The subcarrier index for each 20 MHz within the second 80 MHz (fifth through eighth S_20_160): The DRU subcarrier index for each 20 MHz defined in the above 80 MHz (first through fourth S_20_80)

[0415] The subcarrier index for each 20 MHz within the third 80 MHz (ninth through twelfth S_20_160): The DRU subcarrier index for each 20 MHz defined in the above 80 MHz (first through fourth S_20_80) + 1024

[0416] For example, it can be expressed as follows:

[0417] First S_20_240 = first S_20_80 - 1024;

[0418] Second S_20_240 = second S_20_80 - 1024;

[0419] Third S_20_240 = third S_20_80 - 1024;

[0420] Fourth S_20_240 = fourth S_20_80 - 1024;

[0421] Fifth S_20_240 = first S_20_80;

[0422] Sixth S_20_240 = second S_20_80;

[0423] Seventh S_20_240 = third S_20_80;

[0424] Eighth S_20_240 = fourth S_20_80;

[0425] Ninth S_20_240 = first S_20_80 + 1024;

[0426] Tenth S_20_240 = second S_20_80 + 1024;

[0427] Eleventh S_20_240 = third S_20_80 + 1024; and

[0428] The twelfth S_20_240 = the fourth S_20_80 + 1024.

[0429] Embodiment 6-5

[0430] The subcarrier index (S_20_320) at a specific 20MHz location within a 320MHz bandwidth can be defined as follows:

[0431] Subcarrier indices for each 20MHz segment within the first 160MHz (first to eighth S_20_320): DRU subcarrier indices for each 20MHz segment defined in the aforementioned 160MHz segment (first to eighth S_20_160) - 1024

[0432] The subcarrier index for each 20MHz within the second 160MHz (Ninth to Sixteenth S_20_320): The DRU subcarrier index for each 20MHz defined in the above 160MHz (First to Eighth S_20_160) + 1024

[0433] For example, it can be expressed as follows:

[0434] First S_20_320 = First S_20_160 - 1024;

[0435] Second S_20_320 = Second S_20_160 - 1024;

[0436] The third S_20_320 = the third S_20_160-1024;

[0437] The fourth S_20_320 = the fourth S_20_160 - 1024;

[0438] Fifth S_20_320 = Fifth S_20_160 - 1024;

[0439] The sixth S_20_320 = the sixth S_20_160 - 1024;

[0440] The seventh S_20_320 = the seventh S_20_160 - 1024;

[0441] The eighth S_20_320 = the eighth S_20_160 - 1024;

[0442] Ninth S_20_320 = First S_20_160 + 1024;

[0443] The tenth S_20_320 = the second S_20_160 + 1024;

[0444] Eleventh S_20_320 = Third S_20_160 + 1024;

[0445] Twelfth S_20_320 = Fourth S_20_160 + 1024;

[0446] Thirteenth S_20_320 = Fifth S_20_160 + 1024;

[0447] Fourteenth S_20_320 = Sixth S_20_160 + 1024;

[0448] Fifteenth S_20_320 = Seventh S_20_160 + 1024;

[0449] Sixteenth S_20_320 = Eighth S_20_160 + 1024.

[0450] Embodiment 6-6

[0451] The subcarrier index (S_20_480) at a specific 20 MHz of a 480 MHz bandwidth can be defined as follows.

[0452] The subcarrier index (first through eighth S_20_480) of each 20 MHz within the first 160 MHz: the DRU subcarrier index (first through eighth S_20_160) defined in the above 160 MHz - 2048

[0453] The subcarrier index (ninth through sixteenth S_20_480) of each 20 MHz within the second 160 MHz: the DRU subcarrier index (first through eighth S_20_160) defined in the above 160 MHz

[0454] The subcarrier index (seventeenth through twenty-fourth S_20_480) of each 20 MHz within the third 160 MHz: the DRU subcarrier index (first through eighth S_20_160) defined in the above 160 MHz + 2048

[0455] For example, it can be expressed as follows:

[0456] First S_20_480 = First S_20_160 - 2048;

[0457] Second S_20_480 = Second S_20_160 - 2048;

[0458] Third S_20_480 = Third S_20_160 - 2048;

[0459] Fourth S_20_480 = Fourth S_20_160 - 2048;

[0460] Fifth S_20_480 = Fifth S_20_160 - 2048;

[0461] Sixth S_20_480 = Sixth S_20_160 - 2048;

[0462] Seventh S_20_480 = Seventh S_20_160 - 2048;

[0463] Eighth S_20_480 = Eighth S_20_160 - 2048;

[0464] Ninth S_20_480 = First S_20_160;

[0465] Tenth S_20_480 = Second S_20_160;

[0466] Eleventh S_20_480 = Third S_20_160;

[0467] Twelfth S_20_480 = Fourth S_20_160;

[0468] Thirteenth S_20_480 = Fifth S_20_160;

[0469] Fourteenth S_20_480 = Sixth S_20_160;

[0470] Fifteenth S_20_480 = Seventh S_20_160;

[0471] Sixteenth S_20_480 = Eighth S_20_160;

[0472] Seventeenth S_20_480 = First S_20_160 + 2048;

[0473] Eighteenth S_20_480 = Second S_20_160 + 2048;

[0474] Nineteenth S_20_480 = Third S_20_160 + 2048;

[0475] Twentieth S_20_480 = Fourth S_20_160 + 2048;

[0476] Twenty First S_20_480 = Fifth S_20_160 + 2048;

[0477] Twenty Second S_20_480 = Sixth S_20_160 + 2048;

[0478] Twenty Third S_20_480 = Seventh S_20_160 + 2048;

[0479] Twenty-fourth S_20_480 = Eighth S_20_160 + 2048.

[0480] Figure 15

[0481] The subcarrier index (S_20_640) at a particular 20 MHz within a 640 MHz bandwidth can be defined as follows:

[0482] The subcarrier index (first through sixteenth S_20_640) for each 20 MHz within the first 320 MHz: The DRU subcarrier index (first through sixteenth S_20_320) defined above for each 20 MHz in the 320 MHz - 2048

[0483] The subcarrier index (seventeenth through thirty-second S_20_640) for each 20 MHz within the second 320 MHz: The DRU subcarrier index (first through sixteenth S_20_320) defined above for each 20 MHz in the 320 MHz + 2048

[0484] For example, it can be expressed as follows:

[0485] First S_20_640 = First S_20_320 - 2048;

[0486] Second S_20_640 = Second S_20_320 - 2048;

[0487] Third S_20_640 = Third S_20_320 - 2048;

[0488] Fourth S_20_640 = Fourth S_20_320 - 2048;

[0489] Fifth S_20_640 = Fifth S_20_320 - 2048;

[0490] Sixth S_20_640 = Sixth S_20_320 - 2048;

[0491] Seventh S_20_640 = Seventh S_20_320 - 2048;

[0492] Eighth S_20_640 = Eighth S_20_320 - 2048;

[0493] Ninth S_20_640 = Ninth S_20_320 - 2048;

[0494] Tenth S_20_640 = Tenth S_20_320 - 2048;

[0495] Eleventh S_20_640 = Eleventh S_20_320 - 2048;

[0496] Twelfth S_20_640 = Twelfth S_20_320 - 2048;

[0497] Thirteenth S_20_640 = Thirteenth S_20_320 - 2048;

[0498] Fourteenth S_20_640 = Fourteenth S_20_320 - 2048;

[0499] Fifteenth S_20_640 = Fifteenth S_20_320 - 2048;

[0500] Sixteenth S_20_640 = Sixteenth S_20_320 - 2048;

[0501] Seventeenth S_20_640 = First S_20_320 + 2048;

[0502] Eighteenth S_20_640 = Second S_20_320 + 2048;

[0503] Nineteenth S_20_640 = Third S_20_320 + 2048;

[0504] Twentieth S_20_640 = Fourth S_20_320 + 2048;

[0505] Twenty First S_20_640 = Fifth S_20_320 + 2048;

[0506] Twenty Second S_20_640 = Sixth S_20_320 + 2048;

[0507] Twenty Third S_20_640 = Seventh S_20_320 + 2048;

[0508] Twenty Fourth S_20_640 = Eighth S_20_320 + 2048;

[0509] Twenty Fifth S_20_640 = Ninth S_20_320 + 2048;

[0510] Twenty Sixth S_20_640 = Tenth S_20_320 + 2048;

[0511] Twenty Seventh S_20_640 = Eleventh S_20_320 + 2048;

[0512] Twenty Eighth S_20_640 = Twelfth S_20_320 + 2048;

[0513] Twenty Ninth S_20_640 = Thirteenth S_20_320 + 2048;

[0514] thirtieth S_20_640 = fourteenth S_20_320 + 2048;

[0515] thirty-first S_20_640 = fifteenth S_20_320 + 2048;

[0516] thirty-second S_20_640 = sixteenth S_20_320 + 2048.

[0517] Figure 15 is a diagram for explaining a PPDU transmission and reception procedure between a transmitting STA and a receiving STA according to one embodiment of the disclosure. Some of the steps shown in FIG. 11 can be omitted depending on the situation and / or setting. The transmitting apparatus and the receiving STA can be an AP and / or a non-AP STA. ​

[0518] The transmitting STA can acquire control information related to the above-described tone plan (or RU / DRU) (S105). The control information related to the tone plan can include information for a size and a location of the RU, control information related to the RU, information for a frequency band in which the RU is included, and information for a STA that receives the RU.

[0519] The transmitting STA can construct / generate a PPDU based on the acquired control information (S110). The step of constructing / generating a PPDU can mean a step of constructing / generating each field of the PPDU. That is, the step of constructing / generating a PPDU can include a step of constructing / configuring an EHT-SIG-A / B / C field including control information for a tone plan.

[0520] That is, the step of constructing / generating a PPDU can include a step of constructing / configuring a field including control information (e.g., an N-bit map) indicating a size / location of an RU and / or a step of constructing / configuring a field including an identifier (e.g., an AID) of a STA that receives the RU.

[0521] In addition, the step of constructing / generating a PPDU can include a step of generating an STF / LTF sequence transmitted through a specific RU. The STF / LTF sequence can be generated based on a pre-configured STF generation sequence / LTF generation sequence.

[0522] In addition, the step of constructing / generating a PPDU can include a step of generating a data field (i.e., MPDU) transmitted through a specific RU.

[0523] The transmitting STA can transmit the constructed / generated PPDU to the receiving STA (S115).

[0524] ​Specifically, the transmitting STA can perform at least one of a cyclic shift diversity (CSD), a spatial mapping, an inverse discrete Fourier transform (IDFT) / inverse fast Fourier transform (IFFT) operation, and a guard interval (GI) insertion operation.

[0525] The receiving STA can decode the PPDU and acquire control information related to the tone plan (or RU) (S120).

[0526] Specifically, the receiving STA can decode the L-SIG and the EHT-SIG of the PPDU based on the L-STF / LTF and acquire information included in the L-SIG and the EHT-SIG field. Information for various tone plans (i.e., RUs) of the present disclosure can be included in the EHT SIG (EHT-SIG-A / B / C, etc.), and the receiving STA can acquire information for the tone plan (i.e., RU) through the EHT-SIG.

[0527] The receiving STA can decode the remaining portion of the PPDU based on the acquired information for the tone plan (i.e., RU) (S125). For example, the receiving STA can decode the STF / LTF field of the PPDU based on the information for the tone plan (i.e., RU). In addition, the receiving STA can decode the data field of the PPDU based on the information for the tone plan (i.e., RU) and acquire the MPDU included in the data field.

[0528] The receiving STA can also perform a processing operation of delivering the decoded data to a higher layer (e.g., a MAC layer). In addition, when signal generation is instructed from the higher layer to the PHY layer in response to the data delivered to the higher layer, the receiving STA can perform a subsequent operation.

[0529] Unlike the existing WLAN system in which only the RRU is applied, according to the present disclosure, when the application of the DRU is supported, it is possible to improve the efficiency of resource utilization by transmitting / receiving at least one field of the PPDU based on the various sizes of the DRU tone plan applicable to the PPDU of the 20 MHz bandwidth.

[0530] The above-described embodiments are combinations of elements and features of the present disclosure in a predetermined form. Unless otherwise explicitly mentioned, each element or feature should be considered optional. Each element or feature can be implemented in a form not combined with other elements or features. Also, embodiments of the present disclosure can include combinations of some elements and / or features. The order of operations described in embodiments of the present disclosure can be changed. Some elements or features of one embodiment can be included in other embodiments, or can be substituted with corresponding elements or features of other embodiments. It is obvious that embodiments can include claims not explicitly mentioned in relation to other claims, or can be included as new claims by amendment after the application.

[0531] It will be obvious to those skilled in the relevant arts that the present disclosure can be implemented in other specific forms without departing from the essential characteristics of the present disclosure. Therefore, the above detailed description should not be construed in a limiting sense on every aspect, but should be considered illustrative. The scope of the present disclosure should be determined by a reasonable interpretation of the appended claims, and variations within the scope of the present disclosure are included in the scope of the present disclosure.

[0532] The scope of the present disclosure includes software or machine-executable commands (e.g., operating systems, applications, firmware, programs, etc.) that perform operations according to the methods of various embodiments in an apparatus or computer, and non-transitory computer-readable media that cause the software or commands, etc. to be stored and executable in the apparatus or computer. Commands that can be used to program processing systems to perform features described in the present disclosure can be stored in storage media or computer-readable storage media, and features described in the present disclosure can be implemented using computer program products including such storage media. The storage media can include high-speed random access memory such as DRAM, SRAM, DDR RAM, or other random access solid state storage devices, but is not limited thereto, and it can include non-volatile memory such as one or more disk storage devices, optical disk storage devices, flash memory devices, or other non-volatile solid state storage devices. The memory optionally includes one or more storage devices located remotely from the processor. The memory, or alternatively the non-volatile memory devices in the memory, includes non-transitory computer-readable storage media. Features described in the present disclosure can be stored in any one of machine-readable media to control the hardware of the processing system, and can be integrated into software and / or firmware that allows the processing system to interact with other mechanisms using results from embodiments of the present disclosure. Such software or firmware can include application code, device drivers, operating systems, and execution environments / containers, but is not limited thereto.

[0533] Industrial applicability

[0534] The method proposed by the disclosure is mainly described based on an example applied to an IEEE 802.11-based system (5G system), but can be applied to various WLANs or wireless communication systems other than the IEEE 802.11-based system.

Claims

1. A method performed by a first station (STA) in a wireless local area network (WLAN) system, the method comprising: generating a physical layer protocol data unit (PPDU) including one or more fields mapped on one or more distributed resource units (DRUs); and transmitting the PPDU to one or more second STAs over a bandwidth including a first 20 MHz channel and a second 20 MHz channel, wherein the one or more DRUs include a 26-tone DRU that is one of 9 predefined 26-tone DRUs based on the one or more DRUs including the 26-tone DRU, wherein the n-th 26-tone DRU includes an n-th lowest subcarrier among available subcarriers for the first 20 MHz channel and the second 20 MHz channel, respectively, and is defined as every 9th subcarrier based on the n-th lowest subcarrier, n = 1, 2,..., 9, and wherein the available subcarriers in the first 20 MHz channel and the available subcarriers in the second 20 MHz channel are subcarriers among 512 subcarriers within a 40 MHz channel including the first 20 MHz channel and the second 20 MHz channel, excluding 5 direct current (DC) subcarriers, 16 null subcarriers, 23 guard subcarriers, and 36 pilot subcarriers. 2.The method of claim 1, wherein, for the first 20 MHz channel, the two pilot subcarriers for the n-th 26-tone DRU are based on two subcarrier indices included in a first subcarrier index group {-238, -224, -212, -198, -184, -170, -158, -144, -130, -116, -104, -90, -78, -64, -50, -36, -24, -10}, for the second 20 MHz channel, the two pilot subcarriers for the n-th 26-tone DRU are based on two subcarrier indices included in a second subcarrier index group {10, 24, 36, 50, 64, 78, 90, 104, 116, 130, 144, 158, 170, 184, 198, 212, 224, 238}. 3.The method of claim 2, wherein, a mapping relationship between the 9 predefined 26-tone DRUs and 9 26-tone RUs is defined based on, the two pilot subcarriers for the n-th 26-tone DRU correspond to two pilot subcarriers predefined for a 26-tone RU among the 9 26-tone RUs that is mapped to the n-th 26-tone DRU, for the first 20 MHz channel, ​ the two predefined pilot subcarriers are one of pilot subcarrier indices {-238, -224}, {-212, -198}, {-184, -170}, {-158, -144}, {-130, -116}, {-104, -90}, {-78, -64}, {-50, -36}, or {-24, -10}, for the second 20 MHz channel, the two predefined pilot subcarriers are one of pilot subcarrier indices {10, 24}, {36, 50}, {64, 78}, {90, 104}, {116, 130}, {144, 158}, {170, 184}, {198, 212}, or {224, 238}.

4. The method of claim 2, wherein, for the first 20 MHz channel, the two pilot subcarriers for the nth 26-tone DRU correspond to {nth subcarrier index, (n+9)th subcarrier index} among the subcarrier indices included in the first subcarrier index group, for the second 20 MHz channel, the two pilot subcarriers for the nth 26-tone DRU correspond to {nth subcarrier index, (n+9)th subcarrier index} among the subcarrier indices included in the second subcarrier index group.

5. The method of claim 2, wherein, within the first 20 MHz channel, based on defining a first pilot subcarrier index group {-238, -212, -170, -144} for a predefined first 106-tone RU and a second pilot subcarrier index group {-104, -78, -36, -10} for a predefined second 106-tone RU, for the first 26-tone DRU to the fourth 26-tone DRU, assign the subcarrier indices {-238, -212, -170, -144} included in the first subcarrier index group and included in the first pilot subcarrier index group as pilot subcarriers one by one, and assign the subcarrier indices {-90, -64, -50, -24} included in the first subcarrier index group and used as data subcarriers for the predefined second 106-tone RU as pilot subcarriers one by one, and for the sixth 26-tone DRU to the ninth 26-tone DRU, assign the subcarrier indices {-104, -78, -36, -10} included in the first subcarrier index group and included in the second pilot subcarrier index group as pilot subcarriers one by one, and assign the subcarrier indices {-224, -198, -184, -158} included in the first subcarrier index group and used as data subcarriers for the predefined first 106-tone RU as pilot subcarriers one by one, and For the fifth 26-tone DRU, the remaining subcarrier indices included in the first subcarrier index group and not allocated are allocated as pilot subcarriers.

6. The method of claim 2, wherein, within the second 20 MHz channel, based on defining a first pilot subcarrier index group {10, 36, 78, 104} for a predefined first 106-tone RU and a second pilot subcarrier index group {144, 170, 212, 238} for a predefined second 106-tone RU, for the first 26-tone DRU through the fourth 26-tone DRU, the subcarrier indices {10, 36, 78, 104} included in the first subcarrier index group and included in the first pilot subcarrier index group are each allocated as pilot subcarriers, and the subcarrier indices {158, 184, 198, 224} included in the first subcarrier index group and used as data subcarriers for the predefined second 106-tone RU are each allocated as pilot subcarriers, and for the sixth 26-tone DRU through the ninth 26-tone DRU, the subcarrier indices {144, 170, 212, 238} included in the first subcarrier index group and included in the second pilot subcarrier index group are each allocated as pilot subcarriers, and the subcarrier indices {24, 50, 64, 90} included in the first subcarrier index group and used as data subcarriers for the predefined first 106-tone RU are each allocated as pilot subcarriers, and for the fifth 26-tone DRU, the remaining subcarrier indices included in the first subcarrier index group and not allocated are allocated as pilot subcarriers.

7. The method of claim 1, wherein, for the first 20 MHz channel, the first 26-tone DRU includes subcarrier indices -243, -233, -223, -214, -204, -194, -182, -173, -163, -153, -143, -133, -123, -113, -102, -93, -83, -73, -63, -52, -42, -32, -22, and -13, the second 26-tone DRU includes subcarrier indices -242, -232, -222, -213, -203, -193, -181, -172, -162, -152, -142, -132, -122, -112, -101, -92, -82, -72, -62, -51, -41, -31, -21, and -12, the third 26-tone DRU includes subcarrier indices -241, -231, -221, -211, -202, -192, -180, -171, -161, -151, -141, -131, -121, -111, -100, -91, -81, -71, -61, -49, -40, -30, -20, and -11, the fourth 26-tone DRU includes subcarrier indices -240, -230, -220, -210, -201, -191, -179, -170, -160, -150, -140, -130, -120, -110, -99, -90, -80, -70, -60, -48, -39, -29, -19, and -10, A fourth 26-tone DRU includes subcarrier indices -240, -230, -220, -210, -201, -189, -179, -169, -160, -150, -140, -129, -120, -109, -99, -89, -80, -70, -60, -48, -39, -29, -19, and -9, A fifth 26-tone DRU includes subcarrier indices -239, -229, -219, -209, -200, -188, -178, -168, -159, -149, -139, -128, -119, -108, -98, -88, -79, -69, -59, -47, -38, -28, -18, and -8, A sixth 26-tone DRU includes subcarrier indices -237, -228, -218, -208, -199, -187, -177, -167, -157, -148, -138, -127, -118, -107, -97, -87, -77, -68, -58, -46, -37, -27, -17, and -7, A seventh 26-tone DRU includes subcarrier indices -236, -227, -217, -207, -197, -186, -176, -166, -156, -147, -136, -126, -117, -106, -96, -86, -76, -67, -55, -45, -35, -26, -16, and -6, An eighth 26-tone DRU includes subcarrier indices -235, -226, -216, -206, -196, -185, -175, -165, -155, -146, -135, -125, -115, -105, -95, -85, -75, -66, -54, -44, -34, -25, -15, and -5, and A ninth 26-tone DRU includes subcarrier indices -234, -225, -215, -205, -195, -183, -174, -164, -154, -145, -134, -124, -114, -103, -94, -84, -74, -65, -53, -43, -33, -23, -14, and -4, For the second 20 MHz channel, A first 26-tone DRU includes subcarrier indices 4, 14, 23, 33, 43, 53, 65, 74, 84, 94, 103, 114, 124, 134, 145, 154, 164, 174, 183, 195, 205, 215, 225, and 234, A second 26-tone DRU includes subcarrier indices 5, 15, 25, 34, 44, 54, 66, 75, 85, 95, 105, 115, 125, 135, 146, 155, 165, 175, 185, 196, 206, 216, 226, and 235, a third 26-tone DRU includes subcarrier indices 6, 16, 26, 35, 45, 55, 67, 76, 86, 96, 106, 117, 126, 136, 147, 156, 166, 176, 186, 197, 207, 217, 227, and 236, a fourth 26-tone DRU includes subcarrier indices 7, 17, 27, 37, 46, 58, 68, 77, 87, 97, 107, 118, 127, 138, 148, 157, 167, 177, 187, 199, 208, 218, 228, and 237, a fifth 26-tone DRU includes subcarrier indices 8, 18, 28, 38, 47, 59, 69, 79, 88, 98, 108, 119, 128, 139, 149, 159, 168, 178, 188, 200, 209, 219, 229, and 239, a sixth 26-tone DRU includes subcarrier indices 9, 19, 29, 39, 48, 60, 70, 80, 89, 99, 109, 120, 129, 140, 150, 160, 169, 179, 189, 201, 210, 220, 230, and 240, a seventh 26-tone DRU includes subcarrier indices 11, 20, 30, 40, 49, 61, 71, 81, 91, 100, 111, 121, 131, 141, 151, 161, 171, 180, 192, 202, 211, 221, 231, and 241, an eighth 26-tone DRU includes subcarrier indices 12, 21, 31, 41, 51, 62, 72, 82, 92, 101, 112, 122, 132, 142, 152, 162, 172, 181, 193, 203, 213, 222, 232, and 242, and a ninth 26-tone DRU includes subcarrier indices 13, 22, 32, 42, 52, 63, 73, 83, 93, 102, 113, 123, 133, 143, 153, 163, 173, 182, 194, 204, 214, 223, 233, and 243.

8. The method of claim 7, wherein, based on the at least one DRU including a 52-tone DRU that is one of four predefined 52-tone DRUs, and respectively for the first 20 MHz channel and the second 20 MHz channel, a first 52-tone DRU includes subcarriers included in the first 26-tone DRU and the sixth 26-tone DRU, a second 52-tone DRU includes subcarriers included in the second 26-tone DRU and the seventh 26-tone DRU, a third 52-tone DRU includes subcarriers included in the third 26-tone DRU and the eighth 26-tone DRU, and a fourth 52-tone DRU includes subcarriers included in the fourth 26-tone DRU and the ninth 26-tone DRU. The fourth 52-tone DRU includes subcarriers included in the fourth 26-tone DRU and the ninth 26-tone DRU. 9.The method of claim 8, wherein, four pilot subcarriers are allocated for each of the four predefined 52-tone DRUs, and for the first 20 MHz channel, the four pilot subcarriers are based on four subcarrier indices included in a first subcarrier index group {-238, -224, -212, -198, -184, -170, -158, -144, -104, -90, -78, -64, -50, -36, -24, -10}, and for the second 20 MHz channel, the four pilot subcarriers are based on four subcarrier indices included in a second subcarrier index group {10, 24, 36, 50, 64, 78, 90, 104, 144, 158, 170, 184, 198, 212, 224, 238}. 10.The method of claim 9, wherein, a mapping relationship between the four predefined 52-tone DRUs and four 52-tone RUs is defined, the four pilot subcarriers allocated for each 52-tone DRU correspond to four predefined pilot subcarriers for a mapped 52-tone RU among the four 52-tone RUs, and for the first 20 MHz channel, the predefined four pilot subcarriers are one of pilot subcarrier indices {-238, -224, -212, -198}, {-184, -170, -158, -144}, {-104, -90, -78, -64}, or {-50, -36, -24, -10}, and for the second 20 MHz channel, the predefined four pilot subcarriers are one of pilot subcarrier indices {10, 24, 36, 50}, {64, 78, 90, 104}, {144, 158, 170, 184}, or {198, 212, 224, 238}. 11.The method of claim 9, wherein, the four pilot subcarriers correspond to four pilot subcarriers allocated to two 26-tone DRUs for configuring a 52-tone DRU. 12.The method of claim 8, wherein, based on at least one DRU including a 106-tone DRU, the 106-tone DRU being one of two predefined 106-tone DRUs, and for the first 20 MHz channel and the second 20 MHz channel, respectively, a first 106-tone DRU includes subcarriers included in the first 52-tone DRU and the third 52-tone DRU and a first group corresponding to two of four null subcarriers, and for the first 20 MHz channel and the second 20 MHz channel, respectively, a second 106-tone DRU includes subcarriers included in the second 52-tone DRU and the fourth 52-tone DRU and a second group corresponding to two of four null subcarriers. The second 106-tone DRU includes the subcarriers included in the second 52-tone DRU and the fourth 52-tone DRU and a second set corresponding to the other two of the four null subcarriers.

13. The method of claim 12, wherein, for the first 20 MHz channel, based on the indices of the four null subcarriers being -191, -190, -57, and -56, the first set includes subcarrier indices -191 and -57 and the second set includes subcarrier indices -190 and -56, or the first set includes subcarrier indices -190 and -56 and the second set includes subcarrier indices -191 and -57, and for the second 20 MHz channel, based on the indices of the four null subcarriers being 56, 57, 190, and 191, the first set includes subcarrier indices 56 and 190 and the second set includes subcarrier indices 57 and 191, or the first set includes subcarrier indices 57 and 191 and the second set includes subcarrier indices 56 and 190.

14. The method of claim 12, wherein: four pilot subcarriers and four additional data subcarriers are allocated for each of the two pre-defined 106-tone DRUs, and for the first 20 MHz channel, the four pilot subcarriers and the four additional data subcarriers are based on eight subcarrier indices included in a first set of subcarrier indices {-238, -224, -212, -198, -184, -170, -158, -144, -104, -90, -78, -64, -50, -36, -24, -10}, and for the second 20 MHz channel, the four pilot subcarriers and the four additional data subcarriers are based on eight subcarrier indices included in a second set of subcarrier indices {10, 24, 36, 50, 64, 78, 90, 104, 144, 158, 170, 184, 198, 212, 224, 238}.

15. The method of claim 14, wherein, for the first 20 MHz channel and the second 20 MHz channel, respectively, based on two sets of pilot subcarrier indices being defined for two pre-defined 106-tone RUs, the indices of the four pilot subcarriers belong to at least one of the two sets of pilot subcarrier indices.

16. The method of claim 1, wherein, based on a set of subcarrier indices included in each of the one or more DRUs for an x MHz channel within a y MHz bandwidth being represented as S_x_y, the first 20 MHz channel is a first S_20_40 and the second 20 MHz channel is a second S_20_40, a first S_20_80 = a first S_20_40 - 256; a second S_20_80 = a second S_20_40 - 256; Third S_20_80 = First S_20_40 + 256; Fourth S_20_80 = Second S_20_40 + 256.

17. The method of claim 16, wherein, First S_20_160 = First S_20_80 - 512; Second S_20_160 = Second S_20_80 - 512; Third S_20_160 = Third S_20_80 - 512; Fourth S_20_160 = Fourth S_20_80 - 512; Fifth S_20_160 = First S_20_80 + 512; Sixth S_20_160 = Second S_20_80 + 512; Seventh S_20_160 = Third S_20_80 + 512; Eighth S_20_160 = Fourth S_20_80 + 512.

18. The method of claim 16, wherein, First S_20_240 = First S_20_80 - 1024; Second S_20_240 = Second S_20_80 - 1024; Third S_20_240 = Third S_20_80 - 1024; Fourth S_20_240 = Fourth S_20_80 - 1024; Fifth S_20_240 = First S_20_80; Sixth S_20_240 = Second S_20_80; Seventh S_20_240 = Third S_20_80; Eighth S_20_240 = Fourth S_20_80; Ninth S_20_240 = First S_20_80 + 1024; Tenth S_20_240 = Second S_20_80 + 1024; Eleventh S_20_240 = Third S_20_80 + 1024; Twelfth S_20_240 = Fourth S_20_80 + 1024.

19. The method of claim 17, wherein, First S_20_320 = First S_20_160 - 1024; Second S_20_320 = Second S_20_160 - 1024; Third S_20_320 = Third S_20_160 - 1024; Fourth S_20_320 = Fourth S_20_160 - 1024; Fifth S_20_320 = Fifth S_20_160 - 1024; Sixth S_20_320 = Sixth S_20_160 - 1024; Seventh S_20_320 = Seventh S_20_160 - 1024; Eighth S_20_320 = Eighth S_20_160 - 1024; Ninth S_20_320 = First S_20_160 + 1024; Tenth S_20_320 = Second S_20_160 + 1024; Eleventh S_20_320 = Third S_20_160 + 1024; Twelfth S_20_320 = Fourth S_20_160 + 1024; Thirteenth S_20_320 = Fifth S_20_160 + 1024; Fourteenth S_20_320 = Sixth S_20_160 + 1024; Fifteenth S_20_320 = Seventh S_20_160 + 1024; Sixteenth S_20_320 = Eighth S_20_160 + 1024.

20. The method of claim 17, wherein, First S_20_480 = First S_20_160 - 2048; Second S_20_480 = Second S_20_160 - 2048; Third S_20_480 = Third S_20_160 - 2048; Fourth S_20_480 = Fourth S_20_160 - 2048; Fifth S_20_480 = Fifth S_20_160 - 2048; Sixth S_20_480 = Sixth S_20_160 - 2048; Seventh S_20_480 = Seventh S_20_160 - 2048; Eighth S_20_480 = Eighth S_20_160 - 2048; Ninth S_20_480 = First S_20_160; Tenth S_20_480 = Second S_20_160; Eleventh S_20_480 = Third S_20_160; Twelfth S_20_480 = Fourth S_20_160; Thirteenth S_20_480 = Fifth S_20_160; Fourteenth S_20_480 = Sixth S_20_160; Fifteenth S_20_480 = Seventh S_20_160; Sixteenth S_20_480 = Eighth S_20_160; Seventeenth S_20_480 = First S_20_160 + 2048; Eighteenth S_20_480 = Second S_20_160 + 2048; Nineteenth S_20_480 = Third S_20_160 + 2048; Twentieth S_20_480 = Fourth S_20_160 + 2048; Twenty-first S_20_480 = Fifth S_20_160 + 2048; Twenty-second S_20_480 = Sixth S_20_160 + 2048; Twenty-third S_20_480 = Seventh S_20_160 + 2048; Twenty-fourth S_20_480 = Eighth S_20_160 + 2048.

21. The method of claim 19, wherein, First S_20_640 = First S_20_320 - 2048; Second S_20_640 = Second S_20_320 - 2048; Third S_20_640 = Third S_20_320 - 2048; Fourth S_20_640 = Fourth S_20_320 - 2048; Fifth S_20_640 = Fifth S_20_320 - 2048; Sixth S_20_640 = Sixth S_20_320 - 2048; Seventh S_20_640 = Seventh S_20_320 - 2048; Eighth S_20_640 = Eighth S_20_320 - 2048; Ninth S_20_640 = Ninth S_20_320 - 2048; Tenth S_20_640 = Tenth S_20_320 - 2048; Eleventh S_20_640 = Eleventh S_20_320 - 2048; Twelfth S_20_640 = Twelfth S_20_320 - 2048; Thirteenth S_20_640 = Thirteenth S_20_320 - 2048; Fourteenth S_20_640 = Fourteenth S_20_320 - 2048; Fifteenth S_20_640 = Fifteenth S_20_320 - 2048; Sixteenth S_20_640 = Sixteenth S_20_320 - 2048; Seventeenth S_20_640 = First S_20_320 + 2048; Eighteenth S_20_640 = Second S_20_320 + 2048; Nineteenth S_20_640 = Third S_20_320 + 2048; Twentieth S_20_640 = Fourth S_20_320 + 2048; Twenty-first S_20_640 = Fifth S_20_320 + 2048; Twenty-second S_20_640 = Sixth S_20_320 + 2048; Twenty-third S_20_640 = Seventh S_20_320 + 2048; Twenty-fourth S_20_640 = Eighth S_20_320 + 2048; Twenty-fifth S_20_640 = Ninth S_20_320 + 2048; Twenty-sixth S_20_640 = Tenth S_20_320 + 2048; Twenty-seventh S_20_640 = Eleventh S_20_320 + 2048; Twenty-eighth S_20_640 = Twelfth S_20_320 + 2048; Twenty-ninth S_20_640 = Thirteenth S_20_320 + 2048; Thirtieth S_20_640 = Fourteenth S_20_320 + 2048; Thirty-first S_20_640 = Fifteenth S_20_320 + 2048; Thirty-second S_20_640 = Sixteenth S_20_320 + 2048.

22. The method of claim 1, wherein, the one or more DRUs are indicated based on resource unit, RU, allocation information included in the PPDU, or the one or more DRUs are indicated based on RU allocation information included in a trigger frame used to trigger transmission of the PPDU.

23. The method of claim 1, wherein, the PPDU is a downlink PPDU or an uplink trigger-based TB PPDU.

24. The method of claim 1, wherein, the one or more fields include a data field.

25. A first station, STA, apparatus in a wireless local area network, WLAN, system, the apparatus comprising: at least one transceiver; and at least one processor connected to the at least one transceiver, wherein the at least one processor is configured to: generate a physical layer protocol data unit, PPDU, comprising one or more fields, the one or more fields being mapped on one or more distributed resource units, DRUs; and transmit, through the at least one transceiver, the PPDU to one or more second STAs over a bandwidth comprising a first 20 MHz channel and a second 20 MHz channel, wherein, based on the one or more DRUs comprising 26-tone DRUs, the 26-tone DRUs are one of 9 predefined 26-tone DRUs, wherein, for the first 20 MHz channel and the second 20 MHz channel respectively, an nth 26-tone DRU comprises an nth lowest subcarrier among the available subcarriers, and is defined as every 9th subcarrier based on the nth lowest subcarrier, n = 1, 2,..., 9, and wherein, the available subcarriers in the first 20 MHz channel and the available subcarriers in the second 20 MHz channel are subcarriers among 512 subcarriers within a 40 MHz channel comprising the first 20 MHz channel and the second 20 MHz channel, excluding 5 direct current (DC) subcarriers, 16 null subcarriers, 23 guard subcarriers, and 36 pilot subcarriers.

26. A method performed by a second station (STA) in a wireless local area network (WLAN) system, the method comprising: receiving, from a first STA, a physical layer protocol data unit (PPDU) comprising one or more fields over a bandwidth comprising a first 20 MHz channel and a second 20 MHz channel, and decoding the one or more fields mapped on one or more distributed resource units (DRUs), wherein, based on the one or more DRUs comprising 26-tone DRUs, the 26-tone DRUs are one of 9 predefined 26-tone DRUs, wherein, for the first 20 MHz channel and the second 20 MHz channel respectively, an nth 26-tone DRU comprises an nth lowest subcarrier among the available subcarriers, and is defined as every 9th subcarrier based on the nth lowest subcarrier, n = 1, 2,..., 9, and wherein, the available subcarriers in the first 20 MHz channel and the available subcarriers in the second 20 MHz channel are subcarriers among 512 subcarriers within a 40 MHz channel comprising the first 20 MHz channel and the second 20 MHz channel, excluding 5 direct current (DC) subcarriers, 16 null subcarriers, 23 guard subcarriers, and 36 pilot subcarriers.

27. A second station (STA) apparatus in a wireless local area network (WLAN) system, the apparatus comprising: at least one transceiver; and at least one processor connected to the at least one transceiver, wherein the at least one processor is configured to: receive, through the at least one transceiver, a physical layer protocol data unit (PPDU) comprising one or more fields from a first STA over a bandwidth comprising a first 20 MHz channel and a second 20 MHz channel, and decode the one or more fields mapped on one or more distributed resource units (DRUs), wherein, based on the one or more DRUs including 26-tone DRUs, the 26-tone DRUs are one of 9 predefined 26-tone DRUs, wherein, for the first 20MHz channel and the second 20MHz channel respectively, an nth 26-tone DRU includes an nth lowest subcarrier among the available subcarriers, and is defined as every 9th subcarrier based on the nth lowest subcarrier, n = 1, 2,..., 9, and wherein, the available subcarriers in the first 20MHz channel and the available subcarriers in the second 20MHz channel are subcarriers among 512 subcarriers within a 40MHz channel including the first 20MHz channel and the second 20MHz channel, excluding 5 direct current (DC) subcarriers, 16 null subcarriers, 23 guard subcarriers, and 36 pilot subcarriers.

28. A processing apparatus configured to control a station (STA) in a wireless local area network (WLAN) system, the processing apparatus comprising: at least one processor; and at least one computer memory operatively connected to the at least one processor and storing instructions based on execution by the at least one processor for performing a method according to any one of claims 1-24.

29. At least one non-transitory computer-readable medium storing at least one instruction, wherein: execution of the at least one instruction by at least one processor controls an apparatus to perform a method according to any one of claims 1-24 in a wireless local area network (WLAN) system.

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