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. The method according to an embodiment of the present disclosure may comprise the steps of: receiving, by a first station (STA), a trigger frame from a second STA, the trigger frame including first information about a first bandwidth associated with a physical layer protocol data unit (PPDU); and transmitting, by the first STA, the PPDU to the second STA within the first bandwidth on the basis of the trigger frame, wherein, on the basis of a 20 MHz distributed resource unit (DRU) being applied to at least one unit bandwidth included in the first bandwidth, the trigger frame may include second information related to a type of tone plan for the 20 MHz DRU.

Description

Method and device for transmitting or receiving based on a distributed resource unit tone plan in a wireless LAN system

[0001] The present disclosure relates to a method and device for transmitting or receiving based on a distributed resource unit tone plan in a wireless local area network (WLAN) system.

[0002] New technologies have been introduced for wireless local area networks (WLANs) to improve transmission rates, increase bandwidth, enhance reliability, reduce errors, and reduce latency. Among WLAN technologies, the IEEE (Institute of Electrical and Electronics Engineers) 802.11 series of standards can be referred to as Wi-Fi. For example, recently introduced technologies for WLANs include enhancements for Very High Throughput (VHT) in the 802.11ac standard and enhancements for High Efficiency (HE) in the IEEE 802.11ax standard.

[0003] To provide a more advanced wireless communication environment, improved technologies for Extremely High Throughput (EHT) are being discussed. For example, technologies for Multiple Input Multiple Output (MIMO), which supports increased bandwidth, efficient utilization of multiple bands, and increased spatial streams, and for coordination of multiple access points (APs), are being studied. In particular, various technologies are being studied to support low latency or real-time traffic. Furthermore, new technologies are being discussed to support ultra-high reliability (UHR), including improvements or extensions of EHT technology.

[0004] The technical problem of the present disclosure is to provide a method and device for transmitting or receiving based on a distributed resource unit tone plan in a wireless LAN system.

[0005] The technical problem of the present disclosure is to provide a method and device for transmitting and receiving physical layer protocol data units in a wide bandwidth based on an adaptive distributed resource unit tone plan.

[0006] The technical problems to be achieved in the present disclosure are not limited to the technical problems mentioned above, and other technical problems not mentioned can be clearly understood by a person having ordinary skill in the technical field to which the present disclosure belongs from the description below.

[0007] A method according to one embodiment of the present disclosure comprises the steps of: receiving, by a first station (STA), from a second STA, a trigger frame including first information regarding a first bandwidth associated with a physical layer protocol data unit (PPDU); and transmitting, by the first STA to the second STA, the PPDU within the first bandwidth based on the trigger frame, wherein based on a 20 MHz distributed resource unit (DRU) being applied to at least one unit bandwidth included in the first bandwidth, the trigger frame may include second information regarding a type of a tone plan for the 20 MHz DRU.

[0008] According to another embodiment of the present disclosure, a method includes the steps of: transmitting, by a second station (STA), to a first STA, a trigger frame including first information regarding a first bandwidth associated with a physical layer protocol data unit (PPDU); and receiving, by the second STA, the PPDU from the first STA within the first bandwidth based on the trigger frame, wherein based on a 20 MHz distributed resource unit (DRU) being applied to at least one unit bandwidth included in the first bandwidth, the trigger frame may include second information regarding a type of a tone plan for the 20 MHz DRU.

[0009] According to various embodiments of the present disclosure, a method and device for transmitting or receiving based on a distributed resource unit tone plan in a wireless LAN system can be provided.

[0010] According to various embodiments of the present disclosure, a method and apparatus for transmitting and receiving physical layer protocol data units over a wide bandwidth based on an adaptive distributed resource unit tone plan can be provided.

[0011] By various embodiments of the present disclosure, coverage and throughput can be improved through efficient DRU-based transmission.

[0012] The effects that can be obtained from the present disclosure are not limited to the effects mentioned above, and other effects that are not mentioned will be clearly understood by a person having ordinary skill in the art to which the present disclosure pertains from the description below.

[0013] The accompanying drawings, which are incorporated in and are part of the detailed description to aid in understanding the present disclosure, provide embodiments of the present disclosure and, together with the detailed description, describe the technical features of the present disclosure.

[0014] FIG. 1 illustrates a block diagram of a wireless communication device according to one embodiment of the present disclosure.

[0015] FIG. 2 is a diagram showing an exemplary structure of a wireless LAN system to which the present disclosure can be applied.

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

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

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

[0019] FIG. 6 is a drawing for explaining an example of a frame structure used in a wireless LAN system to which the present disclosure can be applied.

[0020] FIG. 7 is a diagram illustrating examples of PPDUs defined in the IEEE 802.11 standard to which the present disclosure can be applied.

[0021] FIGS. 8 to 10 are diagrams for explaining examples of resource units of a wireless LAN system to which the present disclosure can be applied.

[0022] FIG. 11 is a drawing illustrating examples of DRUs to which the present disclosure can be applied.

[0023] FIG. 12 is a drawing showing an exemplary format of a trigger frame to which the present disclosure can be applied.

[0024] FIG. 13 is a drawing for explaining an example of a method performed by a first STA according to the present disclosure.

[0025] FIG. 14 is a drawing for explaining an example of a method performed by a second STA according to the present disclosure.

[0026] FIG. 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 present disclosure.

[0027] Hereinafter, preferred embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. The detailed description set forth below, together with the accompanying drawings, is intended to explain exemplary embodiments of the present disclosure and is not intended to represent the only embodiments in which the present disclosure may be practiced. The following detailed description includes specific details to provide a thorough understanding of the present disclosure. However, one of ordinary skill in the art will appreciate that the present disclosure may be practiced without these specific details.

[0028] In some cases, to avoid obscuring the concepts of the present disclosure, known structures and devices may be omitted or illustrated in block diagram form focusing on the core functions of each structure and device.

[0029] In the present disclosure, when a component is said to be "connected," "coupled," or "connected" to another component, this may include not only a direct connection but also an indirect connection in which another component exists between them. Furthermore, the terms "comprises" or "has" in the present disclosure specify the presence of the mentioned features, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, steps, operations, elements, components, and / or groups thereof.

[0030] In this disclosure, terms such as “first,” “second,” etc. are used only to distinguish one component from another and are not used to limit the components, and do not limit the order or importance between the components unless specifically stated otherwise. Accordingly, within the scope of this disclosure, a first component in one embodiment may be referred to as a second component in another embodiment, and similarly, a second component in one embodiment may be referred to as a first component in another embodiment.

[0031] The terminology used herein is for the purpose of describing particular embodiments and is not intended to limit the scope of the claims. As used in the description of the embodiments and the appended claims, the singular forms "a," "an," and "the" are intended to include the plural forms as well, unless the context clearly dictates otherwise. The term "and / or" as used herein may refer to any one of the associated enumerated items, or is meant to refer to and encompass any and all possible combinations of two or more of them. Furthermore, the use of " / " between words in this disclosure has the same meaning as "and / or" unless otherwise stated.

[0032] The examples of the present disclosure can be applied to various wireless communication systems. For example, the examples of the present disclosure can be applied to a wireless LAN system. For example, the examples of the present disclosure can be applied to a wireless LAN based on the IEEE 802.11a / g / n / ac / ax / be standards. Furthermore, the examples of the present disclosure can be applied to a wireless LAN based on the newly proposed IEEE 802.11bn (or UHR) standard. Additionally, the examples of the present disclosure can be applied to a wireless LAN based on the next-generation standard after IEEE 802.11bn. Furthermore, the examples of the present disclosure can be applied to a cellular wireless communication system. For example, the examples of the present disclosure can be applied to a cellular wireless communication system based on the LTE (Long Term Evolution) series of technologies and the 5G NR (New Radio) series of technologies of the 3rd Generation Partnership Project (3GPP) standard.

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

[0034] FIG. 1 illustrates a block diagram of a wireless communication device according to one embodiment of the present disclosure.

[0035] The first device (100) and the second device (200) illustrated in FIG. 1 may be replaced with various terms such as a terminal, a wireless device, a WTRU (Wireless Transmit Receive Unit), a UE (User Equipment), an MS (Mobile Station), a UT (user terminal), an MSS (Mobile Subscriber Station), an MSS (Mobile Subscriber Unit), an SS (Subscriber Station), an AMS (Advanced Mobile Station), a WT (Wireless terminal), or simply a user. In addition, the first device (100) and the second device (200) may be replaced with various terms such as an access point (AP), a BS (Base Station), a fixed station, a Node B, a BTS (Base Transceiver System), a network, an AI (Artificial Intelligence) system, an RSU (road side unit), a repeater, a router, a relay, a gateway, etc.

[0036] The devices (100, 200) illustrated in FIG. 1 may also be referred to as stations (STAs). For example, the devices (100, 200) illustrated in FIG. 1 may be referred to by various terms such as transmitting device, receiving device, transmitting STA, and receiving STA. For example, the STAs (110, 200) may perform an AP (access point) role or a non-AP role. That is, in the present disclosure, the STAs (110, 200) may perform the functions of an AP and / or a non-AP. When the STAs (110, 200) perform an AP function, they may simply be referred to as APs, and when the STAs (110, 200) perform a non-AP function, they may simply be referred to as STAs. In addition, in the present disclosure, the APs may also be referred to as AP STAs.

[0037] Referring to FIG. 1, the first device (100) and the second device (200) can transmit and receive wireless signals through various wireless LAN technologies (e.g., IEEE 802.11 series). The first device (100) and the second device (200) can include interfaces for a medium access control (MAC) layer and a physical layer (PHY) that follow the provisions of the IEEE 802.11 standard.

[0038] In addition, the first device (100) and the second device (200) may additionally support various communication standards (e.g., 3GPP LTE series, 5G NR series standards, etc.) other than wireless LAN technology. In addition, the device of the present disclosure may be implemented as various devices such as a mobile phone, a vehicle, a personal computer, an AR (Augmented Reality) device, a VR (Virtual Reality) device, etc. In addition, the STA of the present specification may support various communication services such as voice calls, video calls, data communications, autonomous driving, MTC (Machine-Type Communication), M2M (Machine-to-Machine), D2D (Device-to-Device), and IoT (Internet-of-Things).

[0039] A first device (100) includes one or more processors (102) and one or more memories (104), and may further include one or more transceivers (106) and / or one or more antennas (108). The processor (102) controls the memories (104) and / or the transceivers (106), and may be configured to implement the descriptions, functions, procedures, proposals, methods, and / or operational flowcharts disclosed in the present disclosure. For example, the processor (102) may process information in the memories (104) to generate first information / signals, and then transmit a wireless signal including the first information / signals via the transceivers (106). Furthermore, the processor (102) may receive a wireless signal including second information / signals via the transceivers (106), and then store information obtained from signal processing of the second information / signals in the memory (104). The memory (104) may be connected to the processor (102) and may store various information related to the operation of the processor (102). For example, the memory (104) may perform some or all of the processes controlled by the processor (102), or may store software code including instructions for performing the descriptions, functions, procedures, proposals, methods, and / or operation flowcharts disclosed in the present disclosure. Here, the processor (102) and the memory (104) may be part of a communication modem / circuit / chip designed to implement a wireless LAN technology (e.g., IEEE 802.11 series). The transceiver (106) may be connected to the processor (102) and may transmit and / or receive wireless signals via one or more antennas (108). The transceiver (106) may include a transmitter and / or a receiver. The transceiver (106) may be used interchangeably with an RF (Radio Frequency) unit. In the present disclosure, a device may also mean a communication modem / circuit / chip.

[0040] The second device (200) includes one or more processors (202), one or more memories (204), and may further include one or more transceivers (206) and / or one or more antennas (208). The processor (202) controls the memories (204) and / or the transceivers (206), and may be configured to implement the descriptions, functions, procedures, proposals, methods, and / or operational flowcharts disclosed in the present disclosure. For example, the processor (202) may process information in the memory (204) to generate third information / signals, and then transmit a wireless signal including the third information / signals via the transceivers (206). Furthermore, the processor (202) may receive a wireless signal including fourth information / signals via the transceivers (206), and then store information obtained from signal processing of the fourth information / signals in the memory (204). The memory (204) may be connected to the processor (202) and may store various information related to the operation of the processor (202). For example, the memory (204) may perform some or all of the processes controlled by the processor (202), or may store software code including instructions for performing the descriptions, functions, procedures, proposals, methods, and / or operation flowcharts disclosed in the present disclosure. Here, the processor (202) and the memory (204) may be part of a communication modem / circuit / chip designed to implement a wireless LAN technology (e.g., IEEE 802.11 series). The transceiver (206) may be connected to the processor (202) and may transmit and / or receive wireless signals via one or more antennas (208). The transceiver (206) may include a transmitter and / or a receiver. The transceiver (206) may be used interchangeably with an RF unit. In the present disclosure, a device may also mean a communication modem / circuit / chip.

[0041] Hereinafter, the hardware elements of the device (100, 200) will be described in more detail. Although not limited thereto, one or more protocol layers may be implemented by one or more processors (102, 202). For example, one or more processors (102, 202) may implement one or more layers (e.g., functional layers such as PHY, MAC). One or more processors (102, 202) may generate one or more Protocol Data Units (PDUs) and / or one or more Service Data Units (SDUs) according to the descriptions, functions, procedures, proposals, methods, and / or operational flowcharts disclosed in the present disclosure. One or more processors (102, 202) may generate messages, control information, data, or information according to the descriptions, functions, procedures, proposals, methods, and / or operational flowcharts disclosed in the present disclosure. One or more processors (102, 202) can generate signals (e.g., baseband signals) including PDUs, SDUs, messages, control information, data or information according to the functions, procedures, proposals and / or methods disclosed in the present disclosure, and provide the signals to one or more transceivers (106, 206). One or more processors (102, 202) can receive signals (e.g., baseband signals) from one or more transceivers (106, 206) and obtain PDUs, SDUs, messages, control information, data or information according to the descriptions, functions, procedures, proposals, methods and / or operational flowcharts disclosed in the present disclosure.

[0042] One or more processors (102, 202) may be referred to as a controller, a microcontroller, a microprocessor, or a microcomputer. One or more processors (102, 202) may be implemented by hardware, firmware, software, or a combination thereof. For example, one or more Application Specific Integrated Circuits (ASICs), one or more Digital Signal Processors (DSPs), one or more Digital Signal Processing Devices (DSPDs), one or more Programmable Logic Devices (PLDs), or one or more Field Programmable Gate Arrays (FPGAs) may be included in one or more processors (102, 202). The descriptions, functions, procedures, proposals, methods, and / or operational flowcharts disclosed in this disclosure may be implemented using firmware or software, and the firmware or software may be implemented to include modules, procedures, functions, etc. The descriptions, functions, procedures, proposals, methods and / or operation flowcharts disclosed in this disclosure may be implemented using firmware or software configured to perform one or more processors (102, 202) or stored in one or more memories (104, 204) and driven by one or more processors (102, 202). The descriptions, functions, procedures, proposals, methods and / or operation flowcharts disclosed in this disclosure may be implemented using firmware or software in the form of codes, instructions and / or sets of instructions.

[0043] One or more memories (104, 204) may be coupled to one or more processors (102, 202) and may store various forms of data, signals, messages, information, programs, codes, instructions, and / or commands. The one or more memories (104, 204) may be configured as ROM, RAM, EPROM, flash memory, hard drives, registers, cache memory, computer-readable storage media, and / or combinations thereof. The one or more memories (104, 204) may be located internally and / or externally to the one or more processors (102, 202). Additionally, the one or more memories (104, 204) may be coupled to the one or more processors (102, 202) via various technologies, such as wired or wireless connections.

[0044] One or more transceivers (106, 206) can transmit user data, control information, wireless signals / channels, etc., as mentioned in the methods and / or flowcharts of the present disclosure, to one or more other devices. One or more transceivers (106, 206) can receive user data, control information, wireless signals / channels, etc., as mentioned in the descriptions, functions, procedures, proposals, methods and / or flowcharts of the present disclosure, from one or more other devices. For example, one or more transceivers (106, 206) can be coupled to one or more processors (102, 202) and can transmit and receive wireless signals. For example, one or more processors (102, 202) can control one or more transceivers (106, 206) to transmit user data, control information, or wireless signals to one or more other devices. Additionally, one or more processors (102, 202) may control one or more transceivers (106, 206) to receive user data, control information, or wireless signals from one or more other devices. Additionally, one or more transceivers (106, 206) may be coupled to one or more antennas (108, 208), and one or more transceivers (106, 206) may be configured to transmit and receive user data, control information, wireless signals / channels, or the like, as referred to in the descriptions, functions, procedures, proposals, methods, and / or operational flowcharts disclosed in the present disclosure, via one or more antennas (108, 208). In the present disclosure, one or more antennas may be multiple physical antennas or multiple logical antennas (e.g., antenna ports). One or more transceivers (106, 206) can convert received user data, control information, wireless signals / channels, etc. from RF band signals to baseband signals in order to process the received user data, control information, wireless signals / channels, etc. using one or more processors (102, 202).One or more transceivers (106, 206) may convert user data, control information, wireless signals / channels, etc. processed by one or more processors (102, 202) from baseband signals to RF band signals. For this purpose, one or more transceivers (106, 206) may include an (analog) oscillator and / or filter.

[0045] For example, one of the STAs (100, 200) may perform the intended operation of an AP, and the other of the STAs (100, 200) may perform the intended operation of a non-AP STA. For example, the transceivers (106, 206) of FIG. 1 may perform transmission and reception operations of signals (e.g., packets or PPDUs (Physical layer Protocol Data Units) according to IEEE 802.11a / b / g / n / ac / ax / be / bn, etc.). In addition, in the present disclosure, operations in which various STAs generate transmission and reception signals or perform data processing or calculations in advance for transmission and reception signals may be performed in the processors (102, 202) of FIG. 1. For example, an example of an operation for generating a transmission / reception signal or performing data processing or operation in advance for a transmission / reception signal may include 1) an operation for determining / obtaining / configuring / computing / decoding / encoding bit information of a field (SIG (signal), STF (short training field), LTF (long training field), Data, etc.) included in a PPDU, 2) an operation for determining / configuring / obtaining time resources or frequency resources (e.g., subcarrier resources) used for a field (SIG, STF, LTF, Data, etc.) included in a PPDU, 3) an operation for determining / configuring / obtaining a specific sequence (e.g., a pilot sequence, an STF / LTF sequence, an extra sequence applied to SIG) used for a field (SIG, STF, LTF, Data, etc.) included in a PPDU, 4) a power control operation and / or a power saving operation applied to an STA, 5) an operation related to determining / obtaining / configuring / computing / decoding / encoding an ACK signal, etc. Additionally, in the examples below, various information (e.g., information related to fields / subfields / control fields / parameters / power, etc.) used by various STAs for determining / acquiring / configuring / computing / decoding / encoding transmission / reception signals can be stored in the memory (104, 204) of FIG. 1.

[0046] Hereinafter, downlink (DL) refers to a link for communication from an AP STA to a non-AP STA, and downlink PPDUs / packets / signals, etc. can be transmitted and received through the downlink. In downlink communication, the transmitter may be part of an AP STA, and the receiver may be part of a non-AP STA. Uplink (UL) refers to a link for communication from a non-AP STA to an AP STA, and uplink PPDUs / packets / signals, etc. can be transmitted and received through the uplink. In uplink communication, the transmitter may be part of a non-AP STA, and the receiver may be part of an AP STA.

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

[0048] The structure of a wireless LAN system can be composed of multiple components. Through the interaction of multiple components, a wireless LAN that supports transparent STA mobility to the upper layer can be provided. A Basic Service Set (BSS) corresponds to a basic building block of a wireless LAN. FIG. 2 illustrates, by way of example, the existence of two BSSs (BSS1 and BSS2) and the inclusion of two STAs as members of each BSS (STA1 and STA2 are included in BSS1, and STA3 and STA4 are included in BSS2). The oval representing a BSS in FIG. 2 can also be understood as representing a coverage area in which STAs included in the corresponding BSS maintain communication. This area can be referred to as a Basic Service Area (BSA). When an STA moves outside of a BSA, it cannot directly communicate with other STAs within the BSA.

[0049] If we do not consider the DS illustrated in Figure 2, the most basic type of BSS in a wireless LAN is an Independent BSS (IBSS). For example, an IBSS can have a minimal form consisting of only two STAs. For example, assuming other components are omitted, BSS1 consisting of only STA1 and STA2, or BSS2 consisting of only STA3 and STA4, can be representative examples of an IBSS, respectively. Such a configuration is possible when the STAs can communicate directly without an AP. Furthermore, in this type of WLAN, a LAN can be configured when needed rather than being planned in advance, and this can be called an ad-hoc network. Since an IBSS does not include an AP, there is no centralized management entity. That is, in an IBSS, STAs are managed in a distributed manner. In IBSS, all STAs can be mobile STAs, and access to distributed systems (DS) is not permitted, forming a self-contained network.

[0050] An STA's membership in a BSS can dynamically change, for example, when an STA is turned on or off, or when an STA enters or leaves a BSS area. To become a member of a BSS, an STA can join the BSS using a synchronization process. To access all services in the BSS infrastructure, an STA must be associated with the BSS. This association can be dynamically established and may involve the use of a Distribution System Service (DSS).

[0051] In a wireless LAN, the direct STA-to-STA distance can be limited by PHY performance. While this distance limit may be sufficient in some cases, communication between STAs over longer distances may be required in other cases. To support extended coverage, a distributed system (DS) can be configured.

[0052] DS refers to a structure in which BSSs are interconnected. Specifically, a BSS may exist as an extended component of a network composed of multiple BSSs, as illustrated in Figure 2. 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 DSM can be logically distinguished. Each logical medium is used for a different purpose and by different components. These media are neither limited to being identical nor limited to being different. This logical difference between multiple media explains the flexibility of the WLAN architecture (DS architecture or other network architectures). In other words, the WLAN architecture can be implemented in various ways, and the physical characteristics of each implementation can independently specify the WLAN architecture.

[0053] A DS can support mobile devices by providing seamless integration of multiple BSSs and the logical services necessary to handle addresses to destinations. Additionally, a DS may further include a component called a portal, which acts as a bridge for connecting wireless LANs to other networks (e.g., IEEE 802.X).

[0054] An AP is an entity that enables access to a DS through a WM for associated non-AP STAs and also has the functionality of an STA. Data movement between a BSS and a DS can be performed through an AP. For example, STA2 and STA3 illustrated in FIG. 2 have the functionality of an STA and provide the function of allowing associated non-AP STAs (STA1 and STA4) to access the DS. In addition, since all APs are basically STAs, all APs are addressable entities. The address used by an AP for communication on a WM and the address used by an AP for communication on a DSM do not necessarily have to be the same. A BSS consisting of an AP and one or more STAs can be referred to as an infrastructure BSS.

[0055] Data transmitted from one of the STA(s) associated with an AP to the STA address of that AP may always be received on an uncontrolled port and processed by an IEEE 802.1X port access entity. In addition, if the controlled port is authenticated, the transmitted data (or frame) may be forwarded to the DS.

[0056] In addition to the structure of the DS described above, an extended service set (ESS) may be established to provide wider coverage.

[0057] An ESS is a network of arbitrary size and complexity, consisting of DSs and BSSs. An ESS may correspond to a set of BSSs connected to a DS. However, an ESS does not include a DS. An ESS network is characterized by appearing as an IBSS at the Logical Link Control (LLC) layer. STAs within an ESS can communicate with each other, and mobile STAs can move from one BSS to another (within the same ESS) transparently to the LLC. APs within an ESS may have the same SSID (service set identification). The SSID is distinct from the BSSID, which is the identifier of the BSS.

[0058] In a wireless LAN system, no assumptions are made about the relative physical locations of BSSs, and all of the following configurations are possible: BSSs can be partially overlapping, which is commonly used to provide continuous coverage. BSSs can also be physically disconnected, and there is no logical distance limit between them. BSSs can also be physically co-located, which can be used to provide redundancy. Furthermore, one (or more) IBSS or ESS networks can physically co-exist with one (or more) ESS networks. This can occur in cases where an ad-hoc network operates at the same location as an ESS network, where physically overlapping wireless networks are configured by different organizations, or where two or more different access and security policies are required at the same location.

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

[0060] For an STA to set up a link and transmit and receive data on a network, it must first discover the network, perform authentication, establish an association, and complete security authentication procedures. The link setup process can also be referred to as the session initiation process or session setup process. Furthermore, the discovery, authentication, association, and security setup processes of the link setup process can be collectively referred to as the association process.

[0061] In step S310, the STA may perform a network discovery operation. This network discovery operation may include scanning operations by the STA. That is, for the STA to access a network, it must search for available networks. Before joining a wireless network, the STA must identify compatible networks. The process of identifying networks in a specific area is called scanning.

[0062] Scanning methods include active scanning and passive scanning. Figure 3 illustrates a network discovery operation including an active scanning process as an example. In active scanning, an STA performing scanning transmits a probe request frame to discover any APs in the vicinity while moving between channels and waits for a response. The responder transmits a probe response frame in response to the STA that transmitted the probe request frame. Here, the responder may be the STA that last transmitted a beacon frame in the BSS of the channel being scanned. In the BSS, the AP transmits the beacon frame, so the AP becomes the responder. In the IBSS, the STAs within the IBSS take turns transmitting beacon frames, so the responder is not fixed. For example, an STA that transmits a probe request frame on channel 1 and receives a probe response frame on channel 1 can store BSS-related information included in the received probe response frame and move to the next channel (e.g., channel 2) to perform scanning (i.e., transmitting and receiving probe requests / responses on channel 2) in the same manner.

[0063] Although not shown in Figure 3, the scanning operation can also be performed in a passive scanning manner. In passive scanning, the STA performing the scanning moves between channels and waits for a beacon frame. A beacon frame is one of the management frames defined in IEEE 802.11. It announces the existence of a wireless network and is periodically transmitted so that the STA performing the scanning can find the wireless network and participate in the wireless network. In the BSS, the AP performs the role of periodically transmitting the beacon frame, and in the IBSS, the STAs within the IBSS take turns transmitting the beacon frame. When the STA performing the scanning receives a beacon frame, it stores the information about the BSS included in the beacon frame and moves to another channel, recording the beacon frame information on each channel. The STA receiving the beacon frame stores the BSS-related information included in the received beacon frame and moves to the next channel to perform scanning on the next channel in the same manner. Comparing active scanning and passive scanning, active scanning has the advantage of lower delay and power consumption than passive scanning.

[0064] After the STA discovers the network, an authentication process may be performed in step S320. This authentication process may be referred to as the first authentication process to clearly distinguish it from the security setup operation of step S340 described below.

[0065] The authentication process involves the STA sending an authentication request frame to the AP, and the AP responding by sending an authentication response frame to the STA. The authentication frame used for the authentication request / response corresponds to a management frame.

[0066] The authentication frame may include information such as 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. These are just some examples of information that may be included in an authentication request / response frame, and may be replaced with other information or include additional information.

[0067] An STA can send an authentication request frame to an AP. The AP can determine whether to grant authentication to the STA based on the information contained in the received authentication request frame. The AP can provide the result of the authentication process to the STA via an authentication response frame.

[0068] After the STA is successfully authenticated, an association process may be performed in step S330. The association process includes a process in which the STA transmits an association request frame to the AP, and in response, the AP transmits an association response frame to the STA.

[0069] For example, the association request frame may include information about 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, interworking service capabilities, etc. For example, the association response frame may include information about 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 timeout interval (e.g., an association comeback time), overlapping BSS scan parameters, a TIM broadcast response, a Quality of Service (QoS) map, etc. These are just some examples of information that may be included in a combined request / response frame, and may be replaced by other information or include additional information.

[0070] After the STA successfully joins the network, a security setup process may be performed in step S340. The security setup process in step S340 may be referred to as an authentication process through a Robust Security Network Association (RSNA) request / response, the authentication process in step S320 may be referred to as a first authentication process, and the security setup process in step S340 may also be referred to simply as an authentication process.

[0071] The security setup process of step S340 may include, for example, a process of establishing a private key through a four-way handshaking using an Extensible Authentication Protocol over LAN (EAPOL) frame. Furthermore, the security setup process may be performed according to a security method not defined in the IEEE 802.11 standard.

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

[0073] In wireless LAN systems, the basic access mechanism of MAC (Medium Access Control) is Carrier Sense Multiple Access with Collision Avoidance (CSMA / CA). The CSMA / CA mechanism, also known as the Distributed Coordination Function (DCF) of the IEEE 802.11 MAC, essentially employs a "listen before talk" access mechanism. According to this type of access mechanism, the AP and / or STA may perform a Clear Channel Assessment (CCA) to sense the wireless channel or medium for a predetermined time period (e.g., a DCF Inter-Frame Space (DIFS)) before starting transmission. If the sensing result determines that the medium is in an idle state, the AP and / or STA may start transmitting frames through the medium. On the other hand, if the medium is detected to be occupied or busy, the AP and / or STA may not start its own transmission, but may wait for a delay period (e.g., a random backoff period) for medium access before attempting to transmit frames. By applying a random backoff period, multiple STAs are expected to attempt to transmit frames after waiting for different periods of time, thereby minimizing collisions.

[0074] In addition, the IEEE 802.11 MAC protocol provides the Hybrid Coordination Function (HCF). The HCF is based on the DCF and the Point Coordination Function (PCF). The PCF is a polling-based synchronous access method that periodically polls all receiving APs and / or STAs to ensure that they receive data frames. In addition, the HCF has the Enhanced Distributed Channel Access (EDCA) and the HCF Controlled Channel Access (HCCA). The EDCA is a contention-based access method for a provider to provide data frames to multiple users, while the HCCA uses a non-contention-based channel access method that utilizes a polling mechanism. In addition, the HCF includes a medium access mechanism to improve the Quality of Service (QoS) of the wireless LAN, and can transmit QoS data in both the Contention Period (CP) and the Contention Free Period (CFP).

[0075] Referring to Fig. 4, an operation based on a random backoff period is described. When a medium that was occupied / busy changes to an idle state, multiple STAs can attempt to transmit data (or frames). To minimize collisions, each STA can select a random backoff count, wait for the corresponding slot time, and then attempt transmission. The random backoff count has a pseudo-random integer value and can be determined as one of the values ​​in the range of 0 to CW. Here, CW is a contention window parameter value. The CW parameter is given an initial value of CWmin, but can take a value doubled in case of transmission failure (e.g., when an ACK for a transmitted frame is not received). When the CW parameter value becomes CWmax, data transmission can be attempted while maintaining the CWmax value until data transmission is successful, and if data transmission is successful, it is reset to the CWmin value. The CW, CWmin, and CWmax values ​​are 2. n It is desirable to set it to -1 (n=0, 1, 2, ...).

[0076] Once the random backoff process begins, the STA continues to monitor the medium while counting down the backoff slots according to the determined backoff count value. If the medium is monitored as occupied, the countdown stops and waits. When the medium becomes idle, the remaining countdown resumes.

[0077] In the example of FIG. 4, when a packet to be transmitted reaches the MAC of STA3, STA3 can immediately transmit a frame if it confirms that the medium is idle for DIFS. The remaining STAs monitor the medium for occupied / busy states and wait. In the meantime, data to be transmitted may also occur in each of STA1, STA2, and STA5, and each STA can count down the backoff slot according to a random backoff count value selected by each STA after waiting for DIFS if the medium is monitored as idle. Assume that STA2 selects the smallest backoff count value and STA1 selects the largest backoff count value. In other words, this example shows a case where the remaining backoff time of STA5 is shorter than the remaining backoff time of STA1 when STA2 finishes the backoff count and starts frame transmission. STA1 and STA5 briefly stop counting down and wait while STA2 occupies the medium. When STA2's occupation ends and the medium becomes idle again, STA1 and STA5 wait for DIFS and then resume the backoff count that they had stopped. That is, they can start transmitting frames after counting down the remaining backoff slots equal to the remaining backoff time. Since STA5's remaining backoff time is shorter than STA1's, STA5 starts transmitting frames. While STA2 occupies the medium, STA4 may also have data to transmit. From STA4's perspective, when the medium becomes idle, it waits for DIFS, counts down according to its selected random backoff count value, and then starts transmitting frames. In the example of Figure 4, the remaining backoff time of STA5 coincidentally matches the random backoff count value of STA4, in which case a collision may occur between STA4 and STA5. If a collision occurs, neither STA4 nor STA5 will receive an ACK, resulting in a failure in data transmission.In this case, STA4 and STA5 can select a random backoff count value and perform a countdown after doubling the CW value. STA1 waits while the medium is occupied by transmissions from STA4 and STA5, and when the medium becomes idle, it waits for DIFS and can start transmitting frames after the remaining backoff time elapses.

[0078] As in the example of Fig. 4, a data frame is a frame used for transmitting data forwarded to a higher layer, and can be transmitted after a backoff performed after DIFS elapses from when the medium becomes idle. Additionally, a management frame is a frame used for exchanging management information that is not forwarded to a higher layer, and is transmitted after a backoff performed after an IFS elapses, such as DIFS or PIFS (Point coordination function IFS). Subtype frames of a management frame include a beacon, an association request / response, a re-association request / response, a probe request / response, and an authentication request / response. A control frame is a frame used to control access to the medium. The subtype frames of the control frame include Request-To-Send (RTS), Clear-To-Send (CTS), Acknowledgment (ACK), Power Save-Poll (PS-Poll), Block ACK (BlockAck), Block ACK Request (BlockACKReq), Null Data Packet Announcement (NDP), and Trigger. If the control frame is not a response frame to the previous frame, it is transmitted after a backoff performed after the DIFS (Direct Inverse Frame Stop) has elapsed, and if it is a response frame to the previous frame, it is transmitted without a backoff performed after the SIFS (short IFS). The type and subtype of the frame can be identified by the type field and subtype field in the Frame Control (FC) field.

[0079] A QoS (Quality of Service) STA can transmit a frame after a backoff performed after the AIFS (arbitration IFS) for the access category (AC) to which the frame belongs, i.e., AIFS[i] (where i is a value determined by the AC), has elapsed. Here, the frames for which AIFS[i] can be used can be data frames, management frames, and also control frames that are not response frames.

[0080] FIG. 5 is a diagram for explaining a CSMA / CA-based frame transmission operation to which the present disclosure can be applied.

[0081] As mentioned above, the CSMA / CA mechanism includes virtual carrier sensing in addition to physical carrier sensing, in which STAs directly sense the medium. Virtual carrier sensing is intended to address potential issues in medium access, such as the hidden node problem. For virtual carrier sensing, the MAC of an STA can utilize a Network Allocation Vector (NAV). The NAV is a value that an STA that is currently using or has the right to use the medium indicates to other STAs the remaining time until the medium becomes available. Therefore, the value set as NAV corresponds to the period during which the STA transmitting the frame is scheduled to use the medium, and an STA receiving the NAV value is prohibited from accessing the medium during that period. For example, the NAV can be set based on the value of the "duration" field in the MAC header of the frame.

[0082] In the example of FIG. 5, it is assumed that STA1 wants to transmit data to STA2, and STA3 is in a position to overhear some or all of the frames transmitted and received between STA1 and STA2.

[0083] In order to reduce the possibility of collisions in transmissions of multiple STAs in a CSMA / CA-based frame transmission operation, a mechanism using RTS / CTS frames may be applied. In the example of FIG. 5, while STA1 is transmitting, STA3 may determine that the medium is idle based on carrier sensing results. That is, STA1 may correspond to a hidden node for STA3. Alternatively, in the example of FIG. 5, while STA2 is transmitting, STA3 may determine that the medium is idle based on carrier sensing results. That is, STA2 may correspond to a hidden node for STA3. By exchanging RTS / CTS frames before performing data transmission and reception between STA1 and STA2, STAs outside the transmission range of either STA1 or STA2, or STAs outside the carrier sensing range for transmissions from STA1 or STA3, may not attempt to occupy the channel during data transmission and reception between STA1 and STA2.

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

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

[0086] If STA3 cannot overhear a CTS frame from STA2 but can overhear an RTS frame from STA1, STA3 can use the duration information contained in the RTS frame to set a NAV timer for the subsequent consecutively transmitted frame transmission period (e.g., SIFS + CTS frame + SIFS + data frame + SIFS + ACK frame). Alternatively, if STA3 cannot overhear an RTS frame from STA1 but can overhear a CTS frame from STA2, STA3 can use the duration information contained in the CTS frame to set a NAV timer for the subsequent consecutively transmitted frame transmission period (e.g., SIFS + data frame + SIFS + ACK frame). That is, if STA3 can overhear one or more of the RTS or CTS frames from one or more of STA1 or STA2, it can set a NAV accordingly. If STA3 receives a new frame before the NAV timer expires, it can update the NAV timer using the duration information contained in the new frame. STA3 does not attempt channel access until the NAV timer expires.

[0087] If STA1 receives a CTS frame from STA2, it can transmit a data frame to STA2 after SIFS from the time when the CTS frame is completely received. If STA2 successfully receives the data frame, it can transmit an ACK frame in response to the data frame to STA1 after SIFS. STA3 can determine whether the channel is in use through carrier sensing if the NAV timer expires. If STA3 determines that the channel is not in use by another terminal during the DIFS after the NAV timer expires, it can attempt channel access after a contention window (CW) based on a random backoff has elapsed.

[0088] FIG. 6 is a drawing for explaining an example of a frame structure used in a wireless LAN system to which the present disclosure can be applied.

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

[0090] In this way, information transmission / reception in a wireless LAN system is done in the form of frames, and for this purpose, the PHY layer Protocol Data Unit (PPDU) format is defined.

[0091] A basic PPDU may include a Short Training Field (STF), a Long Training Field (LTF), a SIGNAL (SIG) field, and a Data field. The most basic (e.g., non-HT (High Throughput) as illustrated in FIG. 7) PPDU format may consist of only the Legacy-STF (L-STF), Legacy-LTF (L-LTF), Legacy-SIG (L-SIG) fields, and a Data field. Additionally, 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.)) may be included between the L-SIG field and the data field. More specific details will be described later with reference to FIG. 7.

[0092] STF is a signal for signal detection, AGC (Automatic Gain Control), diversity selection, and precise time synchronization, while LTF is a signal for channel estimation, frequency error estimation, etc. STF and LTF can be said to be signals for synchronization and channel estimation of the OFDM physical layer.

[0093] The SIG field may include various information related to PPDU transmission and reception. For example, the L-SIG field may consist of 24 bits and may include a 4-bit Rate field, a 1-bit Reserved bit, a 12-bit Length field, a 1-bit Parity field, and a 6-bit Tail field. The RATE field may include information about the modulation and coding rate of data. For example, the 12-bit Length field may include information about the length or time duration of the PPDU. For example, the value of the 12-bit Length field may be determined based on the type of the PPDU. For example, for a non-HT, HT, VHT, or EHT PPDU, the value of the Length field may be determined as a multiple of 3. For example, for HE PPDU, 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 may include a SERVICE field, a Physical layer Service Data Unit (PSDU), a PPDU TAIL bit, and, if necessary, padding bits. Some bits of the SERVICE field may be used to synchronize the descrambler at the receiving end. The PSDU corresponds to a MAC PDU defined at the MAC layer and may contain data generated / used by upper layers. The PPDU TAIL bit may be used to return the encoder to a 0 state. The padding bit may be used to adjust the length of the data field to a predetermined unit.

[0095] MAC PDUs are 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). A MAC frame is composed of MAC PDUs and can be transmitted / received through the PSDU in the data portion 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 may include control information required for frame transmission / reception. The Duration / ID field may be set to a time for transmitting the corresponding frame, etc. The Address subfields may indicate the receiver address, transmitter address, destination address, and source address of the frame, and some Address subfields may be omitted. For specific details of each subfield of the MAC header, including the Sequence Control, QoS Control, and HT Control subfields, refer to the IEEE 802.11 standard document.

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

[0098] FIG. 7 is a diagram illustrating examples of PPDUs defined in the IEEE 802.11 standard to which the present disclosure can be applied.

[0099] Standards such as IEEE 802.11a / g / n / ac / ax use various PPDU formats. The basic PPDU format (IEEE 802.11a / g) includes L-LTF, L-STF, L-SIG, and Data fields. The basic PPDU format can also be referred to as the non-HT PPDU format (Fig. 7(a)).

[0100] The HT PPDU format (IEEE 802.11n) additionally includes HT-SIG, HT-STF, and HT-LFT(s) fields in addition to the basic PPDU format. The HT PPDU format illustrated in Fig. 7(b) may be referred to as an HT-mixed format. Additionally, an HT-greenfield format PPDU may be defined, which corresponds to a format that does not include L-STF, L-LTF, and L-SIG, but consists of HT-GF-STF, HT-LTF1, HT-SIG, one or more HT-LTF, and Data fields (not illustrated).

[0101] An example of the VHT PPDU format (IEEE 802.11ac) includes VHT SIG-A, VHT-STF, VHT-LTF, and VHT-SIG-B fields in addition to the basic PPDU format (Fig. 7(c)).

[0102] An example of a HE PPDU format (IEEE 802.11ax) additionally includes RL-SIG (Repeated L-SIG), HE-SIG-A, HE-SIG-B, HE-STF, HE-LTF(s), and PE (Packet Extension) fields in addition to the basic PPDU format (Fig. 7(d)). Depending on specific examples of the HE PPDU format, some fields may be excluded or their lengths may vary. For example, the HE-SIG-B field is included in the HE PPDU format for multi-users (MUs), but the HE PPDU format for single users (SUs) does not include the HE-SIG-B. In addition, the HE trigger-based (TB) PPDU format does not include the HE-SIG-B, and the length of the HE-STF field may vary to 8us. The HE ER (Extended Range) SU PPDU format does not include the HE-SIG-B field, and the length of the HE-SIG-A field may vary to 16us. For example, RL-SIG can be configured identically to L-SIG. The receiving STA can determine that the received PPDU is a HE PPDU or an EHT PPDU, described later, based on the presence of RL-SIG.

[0103] The EHT PPDU format may include the EHT MU (multi-user) PPDU of FIG. 7(e) and the EHT TB (trigger-based) PPDU of FIG. 7(f). The EHT PPDU format is similar to the HE PPDU format in that it includes an RL-SIG following an L-SIG, but may include a U (universal)-SIG, an EHT-SIG, an EHT-STF, and an EHT-LTF following the RL-SIG.

[0104] The EHT MU PPDU in FIG. 7(e) corresponds to a PPDU that carries one or more data (or PSDUs) for one or more users. That is, the EHT MU PPDU can be used for both SU transmission and MU transmission. For example, the EHT MU PPDU can correspond to a PPDU for one receiving STA or multiple receiving STAs.

[0105] The EHT TB PPDU of Fig. 7(f) omits the EHT-SIG compared to the EHT MU PPDU. An STA that has received a trigger for UL MU transmission (e.g., a trigger frame or TRS (triggered response scheduling)) can perform UL transmission based on the EHT TB PPDU format.

[0106] The L-STF, L-LTF, L-SIG, RL-SIG, U-SIG (Universal SIGNAL), and EHT-SIG fields can be encoded and modulated to allow legacy STAs to attempt demodulation and decoding, and mapped based on a predetermined subcarrier frequency interval (e.g., 312.5 kHz). These can be referred to as pre-EHT modulated fields. Next, the EHT-STF, EHT-LTF, Data, and PE fields can be encoded and modulated to allow STAs that have successfully decoded non-legacy SIGs (e.g., U-SIG and / or EHT-SIG) and obtained the information contained in the fields, and mapped based on a predetermined subcarrier frequency interval (e.g., 78.125 kHz). These can be referred to as EHT modulated fields.

[0107] Similarly, in the HE PPDU format, the L-STF, L-LTF, L-SIG, RL-SIG, HE-SIG-A, and HE-SIG-B fields may be referred to as pre-HE modulation fields, and the HE-STF, HE-LTF, Data, and PE fields may be referred to as HE modulation fields. Additionally, in the VHT PPDU format, the L-STF, L-LTF, L-SIG, and VHT-SIG-A fields may be referred to as pre-VHT modulation fields, and the VHT STF, VHT-LTF, VHT-SIG-B, and Data fields may be referred to as VHT modulation fields.

[0108] The U-SIG included in the EHT PPDU format of FIG. 7 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 us, and the U-SIG can have a total duration of 8 us. 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] U-SIGs can be configured in 20MHz units. For example, when an 80MHz PPDU is configured, the same U-SIG can be duplicated in 20MHz units. That is, four identical U-SIGs can be included in an 80MHz PPDU. When the bandwidth exceeds 80MHz, for example, for a 160MHz PPDU, the U-SIGs in the first 80MHz unit and the U-SIGs in the second 80MHz unit can be different.

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

[0111] The A bit information transmitted by U-SIG can be divided into version-independent bits and version-dependent bits. For example, U-SIG can be included in a new PPDU format (e.g., UHR PPDU format) not shown in FIG. 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 U-SIG can be fixed or variable. The version-independent bits can be assigned only to U-SIG-1 symbols, or to both U-SIG-1 symbols and U-SIG-2 symbols. The version-independent bits and the version-dependent bits can be called by various names, such as the first control bit and the second control bit.

[0113] For example, the version-independent bits of the U-SIG may include a 3-bit PHY version identifier, which may indicate the PHY version (e.g., EHT, UHR, etc.) of the transmitted and received PPDUs. The version-independent bits of the U-SIG may include a 1-bit UL / DL flag field. The first value of the 1-bit UL / DL flag field relates to UL communication, and the second value of the UL / DL flag field relates to DL communication. The version-independent bits of the U-SIG may include information about the length of a transmission opportunity (TXOP) and information about a BSS color ID.

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

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

[0116] Some of the information required for transmitting and receiving a PPDU may be included in the U-SIG and / or the non-legacy SIG (e.g., EHT-SIG or UHR-SIG, etc.). For example, information about the type of the non-legacy LTF / STF (e.g., EHT-LTF / EHT-STF or UHR-LTF / UHR-STF, etc.), information about the length of the non-legacy LTF and the cyclic prefix (CP) length, information about the guard interval (GI) applicable to the non-legacy LTF, information about preamble puncturing applicable to the PPDU, information about resource unit (RU) allocation, etc. may be included only in the U-SIG, may be included only in the non-legacy SIG, or may 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 may refer to the transmission of a PPDU in which no signal is present in one or more frequency units within the PPDU's bandwidth. For example, the size of the frequency unit (or the resolution of the preamble puncturing) may be defined as 20 MHz, 40 MHz, etc. For example, preamble puncturing may be applied to a PPDU bandwidth greater than a certain size.

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

[0119]

[0120] *Non-legacy SIGs, such as HE-SIG-B and EHT-SIG, may contain common fields and user-specific fields. Common and user-specific fields may be coded separately.

[0121] In some cases, common fields may be omitted. For example, in a compressed mode where non-OFDMA (orthogonal frequency multiple access) is applied, common fields may be omitted, and multiple STAs may receive PPDUs (e.g., data fields of PPDUs) over the same frequency band. In a non-compressed mode where OFDMA is applied, multiple users may receive PPDUs (e.g., data fields of PPDUs) over different frequency bands.

[0122] The number of user-specific fields can be determined based on the number of users. A single user block field can contain up to two user fields. Each user field can be associated with either MU-MIMO allocation or non-MU-MIMO allocation.

[0123] The common field may include CRC bits and Tail bits, the length of the CRC bits may be determined as 4 bits, and the length of the Tail bits may be determined as 6 bits and set to 000000. The common field may include RU allocation information. The RU allocation information may include information about the location of RUs to which multiple users (i.e., multiple receiving STAs) are allocated.

[0124] An RU can contain multiple subcarriers (or tones). RUs can be used when transmitting signals to multiple STAs based on OFDMA techniques. RUs can also be defined when transmitting signals to a single STA. Resources can be allocated on an RU basis for non-legacy STFs, non-legacy LTFs, and data fields.

[0125] Depending on the PPDU bandwidth, an applicable RU size can be defined. The RU may be defined identically or differently for the applicable PPDU format (e.g., HE PPDU, EHT PPDU, UHR PPDU, etc.). For example, in the case of an 80MHz PPDU, the RU arrangements of HE PPDU and EHT PPDU may be different. The applicable RU size, RU number, RU position, DC (direct current) subcarrier position and number, null subcarrier position and number, guard subcarrier position and number, etc. for each PPDU bandwidth can be referred to as a tone plan. For example, a tone plan for a wide bandwidth can be defined in the form of multiple repetitions of a low bandwidth tone plan.

[0126] RUs of different sizes can be defined, such as 26-ton RU, 52-ton RU, 106-ton RU, 242-ton RU, 484-ton RU, 996-ton RU, 2X996-ton RU, 4X996-ton RU, etc. A multiple RU (MRU) is distinguished from multiple individual RUs and corresponds to a group of subcarriers consisting of multiple RUs. For example, one MRU can be defined as 52+26-tons, 106+26-tons, 484+242-tons, 996+484-tons, 996+484+242-tons, 2X996+484-tons, 3X996-tons, or 3X996+484-tons. Additionally, multiple RUs constituting one MRU may or may not be consecutive in the frequency domain.

[0127] The specific size of an RU may be reduced or expanded. Therefore, the specific size of each RU (i.e., the number of corresponding tones) in the present disclosure is not limited and is exemplary. Furthermore, within a given bandwidth (e.g., 20, 40, 80, 160, 320 MHz, etc.) in the present disclosure, the number of RUs may vary depending on the RU size.

[0128] The names of each field in the PPDU formats of FIG. 7 are exemplary and the scope of the present disclosure is not limited by those names. Furthermore, the examples of the present disclosure can be applied not only to the PPDU format exemplified in FIG. 7, but also to a new PPDU format in which some fields are excluded and / or some fields are added based on the PPDU formats of FIG. 7.

[0129] Resource Unit

[0130] FIGS. 8 to 10 are diagrams for explaining examples of resource units of a wireless LAN system to which the present disclosure can be applied.

[0131] Referring to FIGS. 8 to 10, a resource unit (RU) defined in a wireless LAN system is described. An RU may include multiple subcarriers (or tones). An RU may be used when transmitting signals to multiple STAs based on OFDMA techniques. An RU may also be defined when transmitting signals to a single STA. An RU may be used for the STF, LTF, and data fields of a PPDU.

[0132] As illustrated in FIGS. 8 to 10, RUs corresponding to different numbers of tones (i.e., subcarriers) may be used to configure some fields of a 20 MHz, 40 MHz, or 80 MHz X-PPDU (X represents HE, EHT, etc.). For example, resources may be allocated in units of RUs illustrated for the X-STF, X-LTF, and Data fields.

[0133] Figure 8 is a diagram showing an exemplary arrangement of resource units (RUs) used on a 20 MHz band.

[0134] As shown at the top of Fig. 8, 26 units (i.e., units corresponding to 26 tones) may be allocated. Six tones may be used as a guard band in the leftmost band of the 20 MHz band, and five tones may be used as a guard band in the rightmost band of the 20 MHz band. In addition, seven DC tones may be inserted in the center band, i.e., the DC band, and 26 units corresponding to 13 tones may exist on each side of the DC band. In addition, 26 units, 52 units, and 106 units may be allocated to other bands. Each unit may be allocated for an STA or a user.

[0135] The RU arrangement of Fig. 8 can be utilized not only in situations for multiple users (MUs) but also in situations for a single user (SU), in which case it is possible to use one 242-unit as shown at the bottom of Fig. 8. In this case, three DC tones can be inserted.

[0136] In the example of FIG. 8, RUs of various sizes, such as 26-RU, 52-RU, 106-RU, and 242-RU, are exemplified, but the specific sizes of these RUs may be reduced or expanded. Therefore, the specific size of each RU (i.e., the number of corresponding tones) in the present disclosure is not limited and is exemplary. In addition, in the present disclosure, within a given bandwidth (e.g., 20, 40, 80, 160, 320 MHz, ...), the number of RUs may vary depending on the RU size. In the examples of FIG. 9 and / or FIG. 10 described below, the fact that the size and / or number of RUs may be changed is the same as the example of FIG. 8.

[0137] Figure 9 is a diagram showing an exemplary arrangement of resource units (RUs) used on a 40 MHz band.

[0138] As in the example of FIG. 8 where RUs of various sizes were used, the example of FIG. 9 may also use 26-RU, 52-RU, 106-RU, 242-RU, 484-RU, etc. In addition, five DC tones may be inserted at the center frequency, 12 tones may be used as a guard band in the leftmost band of the 40 MHz band, and 11 tones may be used as a guard band in the rightmost band of the 40 MHz band.

[0139] Additionally, as shown, when used for a single user, 484-RU may be used.

[0140] Figure 10 is a diagram showing an exemplary arrangement of resource units (RUs) used on the 80 MHz band.

[0141] As in the examples of FIGS. 8 and 9 where RUs of various sizes were used, the example of FIG. 10 may also use 26-RU, 52-RU, 106-RU, 242-RU, 484-RU, 996-RU, etc. In addition, in the case of 80MHz PPDU, the RU arrangement of HE PPDU and EHT PPDU may be different, and the example of FIG. 10 shows an example of the RU arrangement for 80MHz EHT PPDU. In the example of FIG. 10, 12 tones are used as guard bands in the leftmost band of the 80MHz band, and 11 tones are used as guard bands in the rightmost band of the 80MHz band, which is the same for HE PPDU and EHT PPDU. Unlike the HE PPDU, which has seven DC tones inserted into the DC band and one 26-RU corresponding to 13 tones on each side of the DC band, the EHT PPDU has 23 DC tones inserted into the DC band and one 26-RU corresponding to 13 tones on each side of the DC band. Unlike the HE PPDU, which has one null subcarrier between the 242-RUs other than the center band, the EHT PPDU has five null subcarriers. In the HE PPDU, one 484-RU does not contain a null subcarrier, but in the EHT PPDU, one 484-RU contains five null subcarriers.

[0142] Also, as shown, when used for a single user, 996-RU can be used, in which case the insertion of 5 DC tones is common in both HE PPDU and EHT PPDU.

[0143] An EHT PPDU of 160MHz or higher may be configured with multiple 80MHz subblocks as shown in FIG. 10. The RU layout for each 80MHz subblock may be the same as the RU layout of the 80MHz EHT PPDU as shown in FIG. 10. If an 80MHz subblock of a 160MHz or 320MHz EHT PPDU is not punctured and the entire 80MHz subblock is used as part of an RU or MRU (Multiple RU), the 80MHz subblock may use 996-RU as shown in FIG. 10.

[0144] Here, an MRU corresponds to a group of subcarriers (or tones) composed of multiple RUs, and the multiple RUs constituting an MRU may be RUs of the same size or different sizes. For example, a single MRU may be defined as 52+26-tones, 106+26-tones, 484+242-tones, 996+484-tones, 996+484+242-tones, 2X996+484-tones, 3X996-tones, or 3X996+484-tones. Here, the multiple RUs constituting one MRU may correspond to RUs of small size (e.g., 26, 52, 106) or RUs of large size (e.g., 242, 484, 996, etc.). That is, a single MRU containing both small-sized RUs and large-sized RUs may not be configured / defined. Furthermore, multiple RUs constituting a single MRU may or may not be consecutive in the frequency domain.

[0145] If an 80MHz subblock contains RUs smaller than 996 tones, or portions of the 80MHz subblock are punctured, the 80MHz subblock may use RU layouts other than the 996-tone RUs.

[0146] The RU of the present disclosure can be used for uplink (UL) and / or downlink (DL) communication. For example, when trigger-based UL-MU communication is performed, an STA (e.g., an AP) transmitting 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 triggered response scheduling (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 PPDU can be transmitted to the AP in the same time interval.

[0147] For example, when a DL MU PPDU is configured, an STA (e.g., an AP) transmitting a DL MU PPDU may 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. That is, the transmitting STA (e.g., the AP) may transmit X-STF (e.g., X is HE, EHT, etc.), X-LTF, and Data fields for the first STA through the first RU within one MU PPDU, and may transmit X-STF, X-LTF, and Data fields for the second STA through the second RU. Information about the arrangement of RUs may be signaled through an X-SIG (e.g., X is HE, EHT, U) field of the X-PPDU format.

[0148] Distributed resource units

[0149] Regulations in various regions may impose power spectral density (PSD) limitations in the sub-7GHz (e.g., 6GHz) band. For non-AP STAs in the low power indoor (LPI) band, the PSD limitation may be -1dBm / MHz. For example, for a conventional 52-tone RU, the maximum transmit (Tx) power may be approximately 6dBm.

[0150] Additionally, different restrictions may apply in the 2.4 GHz and 5 GHz bands. For example, a PSD restriction of 10 dBm / MHz may apply in the EU / China / Japan / Korea in the 2.4 GHz band. This would result in a maximum Tx power of approximately 17 dBm for a conventional 52-tone RU. Bypassing the PSD restriction in the 5 GHz band would allow for higher transmit power. For example, the maximum transmit power for a conventional 52-tone RU is 24 dBm, which is still 6 dBm below the maximum allowable effective isotropic radiated power (EIRP) of 30 dBm.

[0151] Overcoming PSD limitations can increase transmit power, thereby improving spectral efficiency or extending range.

[0152] Considering that the PSD limit is defined per MHz for each STA, when distributing tones of small RUs over a wide bandwidth, the tones for each STA are non-contiguous, so each tone can be transmitted at high power. An RU containing such distributed tones is called a distributed RU (DRU), and to distinguish it from an RU containing continuous tones defined in a conventional wireless LAN system (e.g., a system according to IEEE 802.11ax, 11be, etc.) can be called a regular RU (RRU).

[0153] Compared to STAs transmitting on conventional RRUs, STAs transmitting on DRUs can use higher power. For example, a 52-tone DRU across 80 MHz has only one tone per MHz, whereas a 52-tone RRU has approximately 13 tones per MHz. Assuming a PSD limit of -1 dBm / MHz in the 6 GHz LPI band, using a DRU can increase the transmit power by 11 dB for a 52-tone RU. This increased transmit power allows for a higher MCS and longer range.

[0154] FIG. 11 is a drawing illustrating examples of DRUs to which the present disclosure can be applied.

[0155] In the example of Fig. 11, STA1 transmits on DRU1, STA2 transmits on DRU2, and STA3 transmits on DRU3. Each STA can apply a transmission power boost by using a DRU. Compared to cases where RRUs of the same size are used, the DRU applies higher transmission power to all tones, and thus, spectral efficiency can be significantly improved. In this way, the DRU can be applied particularly usefully in UL-OFDMA.

[0156] APs can also utilize DRUs. In some cases, the AP may use only some of DRUs (DRU1, DRU2, and DRU3) to transmit DL-OFDMA to STAs, in which case the transmit power boost due to the use of DRUs may be applied.

[0157] To maximize power boost, tones within a single DRU can be distributed as far apart as possible. For example, a DRU containing one tone per MHz may be considered optimal. The size of a DRU (or the number of available tones contained in a DRU, i.e., the number of tones excluding unusable tones such as null tones, guard tones, and DC tones) can be defined to be the same as the size of an RRU (or the number of available tones contained in an RRU). This can minimize the impact on various technologies that are already defined based on RRUs. The table below shows examples of achievable power boost (in dB) for various DRUs distributed over different bandwidths. The examples in the table below assume the 6 GHz LPI band, and power boost can also be achieved in the 2.4 GHz and 5 GHz bands in other regions. For example, in an 80 MHz UL-OFDMA transmission by 8 users, if each user uses a 106-tone DRU, the overall performance can be improved by approximately 8.13 dB compared to when each user uses a 106-tone RRU. Thus, by using DRUs, the PSD limitation can be overcome and significant gains can be obtained.

[0158] 20MHz bandwidth 40MHz bandwidth 80MHz bandwidth 26-tone RU8.1311.1411.1452-tone RU6.378.1311.14106-tone RU3.366.378.13242-tone RU Not applicable 2.695.12484-tone RU Not applicable Not applicable 2.69

[0159] FIG. 12 is a diagram illustrating an exemplary format of a trigger frame to which the present disclosure may be applied. The trigger frame may allocate resources for one or more TB PPDU transmissions and request TB PPDU transmissions. The trigger frame may also include other information required by an STA transmitting a TB PPDU in response thereto. The trigger frame may include common info and user info list fields in the frame body. The common info field may include information that is commonly applied to one or more TB PPDU transmissions requested by the trigger frame, such as a trigger type, an UL length, whether a subsequent trigger frame exists (e.g., More TF), whether CS (channel sensing) is required, and an UL BW (bandwidth). FIG. 12 illustrates an exemplary format of an EHT variant common info field.

[0160] The 4-bit trigger type subfield can have values ​​from 0 to 15. Among them, the values ​​0, 1, 2, 3, 4, 5, 6, and 7 of the trigger type subfield are defined to correspond to basic, Beamforming Report Poll (BFRP), multi user-block acknowledgement request (MU-BAR), multi user-request to send (MU-RTS), Buffer Status Report Poll (BSRP), groupcast with retries (GCR), MU-BAR, Bandwidth Query Report Poll (BQRP), and NDP Feedback Report Poll (NFRP), respectively, and the values ​​8 to 15 are defined as reserved.

[0161] Among the common information, the trigger dependent common info subfield may include information that is optionally included based on the trigger type.

[0162] A special user info field may be included within the trigger frame. The special user info field does not contain user-specific information, but rather extended common information not provided in the common information field.

[0163] A user information list contains zero or more user information fields. Figure 12 illustrates an example of an EHT variant user information field format.

[0164] The AID12 subfield basically indicates that it is a user information field for an STA with the corresponding AID. In addition, if the AID12 field has a predetermined specific value, it may be utilized 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 contain user-specific information, but contains extended common information not provided in the common information field. For example, the special user information field can be identified by the AID12 value of 2007, and the special user information field flag subfield within the common information field can indicate whether the special user information field is included.

[0165] The RU allocation subfield can indicate the size and location of an RU / MRU. For this purpose, the RU allocation subfield can be interpreted together with the PS160 (primary / secondary 160MHz) subfield of the user information field, the UL BW subfield of the common information field, etc.

[0166] For example, the mapping of B7-B1 of the RU Assignment subfield can be defined together with the settings of the B0 and PS160 subfields of the RU Assignment subfield as shown in Table 2 below. Table 2 shows an example of encoding of the PS160 subfield and the RU Assignment subfield of the EHT Variant User Information Field.

[0167]

[0168]

[0169]

[0170] When B0 of the RU Allocation subfield is set to 0, it may indicate that the RU / MRU allocation is applied to the primary 80 MHz channel, and when its value is set to 1, it may 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 may indicate that the RU / MRU allocation is applied to the lower 80 MHz of the secondary 160 MHz, and when its value is set to 1, it may indicate that the RU allocation is applied to the upper 80 MHz of the secondary 160 MHz.

[0171] In the trigger frame RU allocation table of Table 2, the parameter N can be calculated based on the formula N=2*X1+X0. For a bandwidth of 80 MHz or less, the values ​​of PS160, B0, X0, and X1 can be set to 0. For a bandwidth of 160 MHz and a bandwidth of 320 MHz, the values ​​of PS160, B0, X0, and X1 can be set as shown in Table 3. These settings represent the absolute frequency order for the primary and secondary 80 MHz and 160 MHz channels. The order from left to right represents the order from low frequency to high frequency. The primary 80 MHz channel is represented as P80, the secondary 80 MHz channel is represented as S80, and the secondary 160 MHz channel is represented as S160.

[0172]

[0173] DRU tone plan-based transmission and reception

[0174] As mentioned above, to overcome PSD limitations and improve power gain, a distributed tones / subcarriers (DRU) can be employed instead of a continuous tones / subcarriers (RRU). Below, a 20 MHz DRU tone plan scheme with a 20 MHz distributed bandwidth applied to a specific 20 MHz channel is described when transmitting PPDUs of 40 MHz or more using a DRU.

[0175] FIG. 13 is a diagram illustrating an example of a method performed by a first STA according to the present disclosure. In each of FIG. 13 and FIG. 14 , the first STA may be a non-AP STA and the second STA may be an AP, but is not limited thereto. Each of the first STA and the second STA may be either a non-AP STA or an AP.

[0176] A first STA may receive a trigger frame including first information about a first bandwidth related to a physical layer protocol data unit (PPDU) from a second STA (S1310).

[0177] Specifically, the trigger frame may allocate resources for soliciting PPDU transmission. For example, the trigger frame may include first information related to the bandwidth of the PPDU, and the first information may be indicated / set based on the UL (uplink) BW field of the (UHR) common information field of the trigger frame and / or the UL BW extension field of the (UHR) special user information field of the trigger frame. For example, when a first value is set for the UL BW field and a second value is set for the UL BW extension field, the first information may be indicated based on the first value set in the UL BW field and the second value set in the UL BW extension field. However, this is only one embodiment, and the trigger frame may set / indicate the first information related to the bandwidth of the PPDU through at least one field.

[0178] Here, the size of the first bandwidth indicated by the first information may be 40 MHz or more, but is not limited thereto.

[0179] Additionally or alternatively, the trigger frame may include information indicating that the DRU is applied to at least one unit bandwidth included in the first bandwidth of the PPDU and / or the PPDU. As an example, the trigger frame may include information indicating that the 20 MHz DRU is applied to at least one unit bandwidth included in the first bandwidth.

[0180] For example, based on the application of a 20 MHz DRU to at least one unit bandwidth included in the first bandwidth (by the trigger frame), the trigger frame may include second information relating to a type of tone plan for the 20 MHz DRU. That is, the trigger frame may include second information relating to a type of tone plan for the 20 MHz DRU to be applied to at least one unit bandwidth.

[0181] For example, the second information related to the type of tone plan for the 20 MHz DRU may include information related to one of: i) a tone plan for the first 20 MHz DRU (e.g., a first type of tone plan) based on a predefined first resource unit (RU) tone plan for a 20 MHz channel, or ii) a tone plan for the second 20 MHz DRU (e.g., a second type of tone plan) based on a tone plan corresponding to a particular 20 MHz channel among the predefined second RU tone plans for a 40 MHz channel.

[0182] Here, the predefined tone plan for the 20 MHz channel may correspond to the 20 MHz tone plan described with reference to FIG. 8. Furthermore, the predefined tone plan for the 40 MHz channel may correspond to the 40 MHz tone plan described with reference to FIG. 9. The specific 20 MHz channel may be either a first 20 MHz channel having a higher frequency among the 40 MHz channels or a second 20 MHz channel having a lower frequency among the 40 MHz channels.

[0183] The first STA may apply a specific tone plan based on i) a tone plan for the first 20 MHz DRU (e.g., a first type of tone plan) or ii) a tone plan for the second 20 MHz DRU (e.g., a second type of tone plan) for at least one unit bandwidth of the first bandwidth based on the second information. That is, a specific tone plan based on i) a tone plan for the first 20 MHz DRU or ii) a tone plan for the second 20 MHz DRU may be applied for at least one unit bandwidth.

[0184] For example, a specific tone plan applied to each of at least one unit bandwidth may have a shift value applied to i) a tone plan for a first 20 MHz DRU or ii) a tone plan for a second 20 MHz DRU, and the shift value may be determined based on a position of at least one unit bandwidth. That is, a specific tone plan applied to each of at least one unit bandwidth may be determined as a shift value is applied to each type of tone plan.

[0185] For example, assume that the size of each of at least one unit bandwidth is 20 MHz, the first bandwidth is 40 MHz, and the type of the first 20 MHz DRU tone plan is applied and indicated by the second information. At this time, a specific tone plan of a first unit bandwidth among the first bandwidths may be a tone plan to which a shift value of -128 is applied to the first 20 MHz DRU tone plan, and a specific tone plan of a second unit bandwidth among the first bandwidths may be a tone plan to which a shift value of +128 is applied to the first 20 MHz DRU tone plan.

[0186] That is, a shift value of -128 may be applied to the first unit bandwidth having a lower frequency among at least one unit bandwidth, and a shift value of +128 may be applied to the second unit bandwidth having a higher frequency among at least one unit bandwidth.

[0187] As an example of the present disclosure, the trigger frame includes a (UHR) common information field and a (UHR) special user information field, and the second information may be set to one of i) the 23rd bit (B22), the 27th bit (B26), the 54th bit (B53), the 57th bit (B56) to the 64th bit (B63) of the common information field or ii) the 38th bit (B37) to the 40th bit (B39) of the special user information field.

[0188] As another example of the present disclosure, the trigger frame may include at least one user information field. And, among the at least one user information field, a specific user information field including an RU allocation subfield related to a 20 MHz DRU tone plan may include the second information.

[0189] As another example of the present disclosure, the second information may include a bitmap related to the type of tone plan for a 20 MHz DRU applied to at least one unit bandwidth. That is, the second information may be implemented in the form of a bitmap indicating the type of tone plan applied to each unit bandwidth.

[0190] The first STA can transmit a PPDU to the second STA within the first bandwidth based on the trigger frame (S1320).

[0191] Specifically, the first STA may generate a PPDU using information included in the trigger frame and transmit the generated PPDU to the second STA. A specific tone plan based on a tone plan for a specific type of 20 MHz DRU associated with the second information included in the trigger frame may be applied to the PPDU (e.g., the first bandwidth over which the PPDU is transmitted).

[0192] For example, a PPDU may include a U(universal)-SIG(signal) field or a UHR(ultra-high reliability)-SIG field. In addition, the U-SIG field or the UHR-SIG field may include third information about the type of tone plan for the 20 MHz DRU applied to the PPDU. Accordingly, the second STA can check information about the tone plan applied to the PPDU.

[0193] The method described in the example of FIG. 13 may be performed by the first device (100) of FIG. 1. For example, one or more processors (102) of the first device (100) of FIG. 1 may receive a trigger frame including first information about a first bandwidth associated with a PPDU from a second STA through one or more transceivers (106). The one or more processors (102) may transmit the PPDU to the second STA within the first bandwidth through one or more transceivers (106) based on the trigger frame.

[0194] Furthermore, one or more memories (104) of the first device (100) may store commands for performing the method described in the example of FIG. 13 or the examples described below when executed by one or more processors (102).

[0195] FIG. 14 is a drawing for explaining an example of a method performed by a second STA according to the present disclosure.

[0196] The second STA may transmit a trigger frame containing first information about the first bandwidth associated with the PPDU to the first STA (S1410). The configuration of the trigger frame has been described with reference to FIG. 13, so a redundant description will be omitted.

[0197] The second STA may receive a PPDU from the first STA within a first bandwidth based on a trigger frame (S1420). A specific tone plan based on a tone plan for a specific type of 20 MHz DRU associated with the second information included in the trigger frame may be applied to the PPDU (e.g., the first bandwidth over which the PPDU is transmitted). Furthermore, the second STA may receive a PPDU to which a specific tone plan based on a tone plan for a specific type of 20 MHz DRU is applied within the first bandwidth.

[0198] The method described in the example of FIG. 14 may be performed by the second device (200) of FIG. 1. For example, one or more processors (202) of the second device (200) of FIG. 1 may receive a trigger frame including first information about a first bandwidth associated with a PPDU from a first STA through one or more transceivers (206). The one or more processors (202) may receive a PPDU from the first STA within the first bandwidth through one or more transceivers (206) based on the trigger frame.

[0199] Furthermore, one or more memories (204) of the second device (200) may store instructions for performing the method described in the example of FIG. 14 or the examples described below when executed by one or more processors (202).

[0200] Below, we will specifically describe a 20 MHz DRU tone plan scheme with a 20 MHz distributed bandwidth applied to a specific 20 MHz channel when transmitting a PPDU in a wideband (e.g., bandwidth greater than 40 MHz).

[0201] Example 1

[0202] Example 1 relates to an adaptive 20 MHz DRU tone plan when transmitting PPDUs over a wide bandwidth.

[0203] For power gain, DRU-applied PPDUs can be transmitted and received, and DL OFDMA transmission using MU PPDUs or UL OFDMA transmission using TB PPDUs can be performed. In particular, in PPDU transmissions above 40 MHz, a 20 MHz DRU tone plan with a 20 MHz distributed bandwidth can be applied to a specific 20 MHz channel.

[0204] For example, if a 20 MHz channel is punctured within a specific 80 MHz of a PPDU, a 20 MHz DRU tone plan with a 20 MHz distributed bandwidth may be applied to the 20 MHz channel comprising the punctured channel and the 40 MHz channel. Considering the above-described situation, the 20 MHz DRU tone plan may be configured in a manner according to two embodiments (Embodiments 1-1 and 1-2).

[0205] Example 1-1

[0206] Example 1-1 is about defining a 20 MHz DRU tone plan applied to a 20 MHz PPDU based on a 20 MHz tone plan in a basic wireless LAN system, and a method of shifting and utilizing the defined 20 MHz DRU tone plan.

[0207] The method according to Example 1-1 is a method of newly defining a 20 MHz DRU tone plan applicable to 20 MHz PPDU transmission while maintaining the left / right guard tones and DC tone (or / and null tone) in the 20 MHz tone plan defined in the basic wireless LAN system (e.g., the 20 MHz tone plan illustrated in FIG. 8). A shift may be applied to the newly defined 20 MHz DRU tone plan, and the (shifted) 20 MHz DRU tone plan may be applied on a specific 20 MHz channel when transmitting a PPDU of 40 MHz or more.

[0208] When the above-described method is applied, in a PPDU transmission situation of 40 MHz or higher, if a 20 MHz operating STA supporting DRU is the transmitter, the data loss problem in the guard tone and DC tone due to filtering can be resolved, and the problem related to the DC offset can be resolved. If a 20 MHz operating STA is the receiver, the data loss problem in the DC tone due to filtering can be resolved, and the problem related to the DC offset can be resolved.

[0209] Below, an example of the configuration of a 20 MHz DRU tone plan is described when the method according to Example 1-1 is applied. The method described below can be applied not only to a 20 MHz DRU tone plan but also to tone plans of various bandwidths.

[0210] 26 DRU Index

[0211] A total of 26 DRUs can be allocated nine tones, one tone at a time, from the lowest available tone to the highest available tone. At this time, the left / right guard tones and the DC tone (or / and null tone) can be maintained in the 20 MHz tone plan defined in the basic wireless LAN system (e.g., the 20 MHz tone plan illustrated in FIG. 8).

[0212] In the description of the present disclosure, "a:b:c" means that tones starting from a tone (subcarrier) index to c tone (subcarrier) index are allocated to the corresponding (D)RU in units of b (i.e., at intervals of b tone (subcarrier)). For example, "-121:9:-76" may mean tones (subcarriers) at indices of -121, -112, -103, -94, -85, -76. And, the notation "DRU-x" means that the index of the DRU is x.

[0213] Below is the tone index configuration that comprises 9 26 DRUs:

[0214] - 26 DRU-1: -121:9:-76, -66:9:-12, 4:9:67, 77:9:113

[0215] - 26 DRU-2: -120:9:-75, -65:9:-11, 5:9:68, 78:9:114

[0216] - 26 DRU-3: -119:9:-74, -64:9:-10, 6:9:60, 70:9:115

[0217] - 26 DRU-4: -118:9:-73, -63:9:-9, 7:9:61, 71:9:116

[0218] - 26 DRU-5: -117:9:-72, -62:9:-8, 8:9:62, 72:9:117

[0219] - 26 DRU-6: -116:9:-71, -61:9:-7, 9:9:63, 73:9:118

[0220] - 26 DRU-7: -115:9:-70, -60:9:-6, 10:9:64, 74:9:119

[0221] - 26 DRU-8: -114:9:-78, -68:9:-5, 11:9:65, 75:9:120

[0222] - 26 DRU-9: -113:9:-77, -67:9:-4, 12:9:66, 76:9:121

[0223] 52 DRU Index

[0224] The 52 DRU is configured as a combination of two 26 DRUs, and can be defined as follows to maximize tone dispersion:

[0225] - 52 DRU-1: Combination of 26 DRU-1 and 26 DRU-6

[0226] - 52 DRU-2: combination of 26 DRU-2 and 26 DRU-7

[0227] - 52 DRU-3: combination of 26 DRU-3 and 26 DRU-8

[0228] - 52 DRU-4: Combination of 26 DRU-4 and 26 DRU-9

[0229] 106 DRU Index

[0230] The 106 DRUs can be configured as a combination of i) two 52 DRUs and ii) two null tones ±{122, 69}. For example, the null tone can be used as a data tone, and can be defined as follows to maximize tonal distribution. The null tones may not overlap with each other between DRUs.

[0231] - 106 DRU-1: i) 52 DRU-1, 52 DRU-3 and ii) null tone {-122, 69} or null tone {-69, 122} combination, or

[0232] i) 52 DRU-1, 52 DRU-3 and ii) null tone {-122, 122} or null tone {-69, 69} combinations.

[0233] - 106 DRU-2: i) 52 DRU-2, 52 DRU-4 and ii) null tone {-69, 122} or null tone {-122, 69} combination, or

[0234] i) 52 DRU-2, 52 DRU-4 and ii) null tone {-69, 69} or null tone {-122, 122}

[0235] In addition to the above-described allocation method, two additional null tones can be selected without overlapping each other. As another example, when defining mapping rules between DRUs and RRUs based on the RU allocation subfield of the basic wireless LAN system, the null tones used by 106 RRUs mapped to 106 DRUs can be used. As another example, four null tones can be defined as null-1, null-2, null-3, and null-4 in that order, so that odd-numbered null combinations and even-numbered null combinations can be assigned to each of the 106 DRUs.

[0236] Below, the configuration of the tone index of each DRU is described when the DRU is applied to each of the 20 MHz(s) included in the bandwidth of 40 MHz or more.

[0237] Example 1-1-1: Tone index at each 20 MHz within 40 MHz

[0238] - Tone index of the first 20 MHz of 40 MHz: "DRU tone index of 20 MHz described in Example 1-1" - 128

[0239] - Second 20 MHz tone index of 40 MHz: "20 MHz DRU tone index described in Example 1-1" + 128

[0240] Example 1-1-2: Tone index at each 20 MHz within 80 MHz

[0241] - Tone index of each 20 MHz within the first 40 MHz of 80 MHz: "DRU tone index of each 20 MHz defined in 40 MHz according to Example 1-1-1" - 256

[0242] - Tone index of each 20 MHz within the second 40 MHz of 80 MHz: "DRU tone index of each 20 MHz defined in 40 MHz according to Example 1-1-1" + 256

[0243] Example 1-1-3: Tone index at each 20 MHz within 160 MHz

[0244] - Tone index of each 20 MHz within the first 80 MHz of 160 MHz: "DRU tone index of each 20 MHz defined in 80 MHz according to Example 1-1-2" - 512

[0245] - Tone index of each 20 MHz within the second 80 MHz of 160 MHz: "DRU tone index of each 20 MHz defined in 80 MHz according to Example 1-1-2" + 512

[0246] Example 1-1-4: Tone index at each 20 MHz within 240 MHz

[0247] - Tone index of each 20 MHz within the first 80 MHz of 240 MHz: "DRU tone index of each 20 MHz defined in 80 MHz according to Example 1-1-2" - 1024

[0248] - Tone index of each 20 MHz within the second 80 MHz of 240 MHz: "DRU tone index of each 20 MHz defined in 80 MHz according to Example 1-1-2"

[0249] - Tone index of each 20 MHz within the third 80 MHz of 240 MHz: "DRU tone index of each 20 MHz defined in 80 MHz according to Example 1-1-2" + 1024

[0250] Example 1-1-5: Tone index at each 20 MHz within 320 MHz

[0251] - Tone index of each 20 MHz within the first 160 MHz of 320 MHz: "DRU tone index of each 20 MHz defined in 160 MHz according to Example 1-1-3" - 1024

[0252] - Tone index of each 20 MHz within the second 80 MHz of 320 MHz: "DRU tone index of each 20 MHz defined at 160 MHz according to Example 1-1-3" + 1024

[0253] Example 1-1-6: Tone index at each 20 MHz within 480 MHz

[0254] - Tone index of each 20 MHz within the first 160 MHz of 480 MHz: "DRU tone index of each 20 MHz defined in 160 MHz according to Example 1-1-3" - 2048

[0255] - Tone index of each 20 MHz within the second 160 MHz of 480 MHz: "DRU tone index of each 20 MHz defined in 160 MHz according to Example 1-1-3"

[0256] - Tone index of each 20 MHz within the third 160 MHz of 480 MHz: "DRU tone index of each 20 MHz defined in 160 MHz according to Example 1-1-3" + 2048

[0257] Example 1-1-7: Tone index at each 20 MHz within 640 MHz

[0258] - Tone index of each 20 MHz within the first 320 MHz of 640 MHz: "DRU tone index of each 20 MHz defined in 320 MHz according to Example 1-1-5" - 2048

[0259] - Tone index of each 20 MHz within the second 320 MHz of 640 MHz: "DRU tone index of each 20 MHz defined in 320 MHz according to Example 1-1-5" + 2048

[0260] Example 1-2

[0261] Example 1-2 relates to a method of newly defining a 20 MHz DRU tone plan applied to each of 20 MHz of a low frequency and 20 MHz of a high frequency of a 40 MHz PPDU based on a 40 MHz tone plan in a basic wireless LAN system, and applying the newly defined 20 MHz DRU tone plan by shifting it.

[0262] The method according to embodiment 1-2 includes a method of newly defining a 20 MHz DRU tone plan applied to each of the 20 MHz lower frequency and the 20 MHz higher frequency of a 40 MHz PPDU while maintaining the left / right guard tones and the DC tone (or / and the null tone) in the 40 MHz tone plan defined in the basic wireless LAN system (e.g., the 40 MHz tone plan illustrated in FIG. 9).

[0263] And, by applying a shift to the newly defined 20 MHz DRU tone plan, the 20 MHz DRU tone plan with the shift applied can be applied to a specific 20 MHz channel when transmitting a PPDU of 80 MHz or more.

[0264] Considering that the tone plan of 40 MHz or higher on a basic wireless LAN system is a shifted form of the 40 MHz tone plan, the method according to embodiment 1-2 may be easy from an implementation perspective. In addition, if an STA with the capability of operating at 40 MHz or higher supports the DRU in a PPDU transmission of 40 MHz or higher, both the transmitter and receiver can operate without data loss and DC offset issues.

[0265] Below, an example of the configuration of a 20 MHz DRU tone plan is described when the method according to Example 1-2 is applied. The method described below can be applied not only to a 20 MHz DRU tone plan but also to tone plans of various bandwidths.

[0266] 26 DRU Index

[0267] (Out of 40 MHz) Lower 20 MHz: 26 DRU tones can be allocated, one tone at a time, from the lowest available tone to the highest available tone, for a total of 9 tones.

[0268] - 26 DRU-1: -243:9:-198, -187:9:-142, -132:9:-114, -104:9:-59, -48:9:-12

[0269] - 26 DRU-2: -242:9:-197, -186:9:-141, -131:9:-113, -103:9:-58, -47:9:-11

[0270] - 26 DRU-3: -241:9:-196, -185:9:-140, -130:9:-112, -102:9:-66, -55:9:-10

[0271] - 26 DRU-4: -240:9:-195, -184:9:-139, -129:9:-111, -101:9:-65, -54:9:-9

[0272] - 26 DRU-5: -239:9:-194, -183:9:-138, -128:9:-119, -109:9:-64, -53:9:-8

[0273] - 26 DRU-6: -238:9:-193, -182:9:-146, -136:9:-118, -108:9:-63, -52:9:-7

[0274] - 26 DRU-7: -237:9:-192, -181:9:-145, -135:9:-117, -107:9:-62, -51:9:-6

[0275] - 26 DRU-8: -236:9:-200, -189:9:-144, -134:9:-116, -106:9:-61, -50:9:-5

[0276] - 26 DRU-9: -235:9:-199, -188:9:-143, -133:9:-115, -105:9:-60, -49:9:-4

[0277] (Out of 40 MHz) High 20 MHz: 26 DRU tones can be allocated, one tone at a time, from the lowest available tone to the highest available tone, for a total of 9 tones.

[0278] - 26 DRU-1: 4:9:49, 60:9:105, 115:9:133, 143:9:188, 199:9:235

[0279] - 26 DRU-2: 5:9:50, 61:9:106, 116:9:134, 144:9:189, 200:9:236

[0280] - 26 DRU-3: 6:9:51, 62:9:107, 117:9:135, 145:9:181, 192:9:237

[0281] - 26 DRU-4: 7:9:52, 63:9:108, 118:9:136, 146:9:182, 193:9:238

[0282] - 26 DRU-5: 8:9:53, 64:9:109, 119:9:128, 138:9:183, 194:9:239

[0283] - 26 DRU-6: 9:9:54, 65:9:101, 111:9:129, 139:9:184, 195:9:240

[0284] 26 DRU-7: 10:9:55, 66:9:102, 112:9:130, 140:9:185, 196:9:241

[0285] 26 DRU-8: 11:9:47, 58:9:103, 113:9:131, 141:9:186, 197:9:242

[0286] 26 DRU-9: 12:9:48, 59:9:104, 114:9:132, 142:9:187, 198:9:243

[0287] 52 DRU Index

[0288] The 52 DRU can be configured as a combination of two 26 DRUs, and can be defined as follows to maximize tone dispersion:

[0289] 52 DRU-1: Combination of 26 DRU-1 and 26 DRU-6

[0290] 52 DRU-2: Combination of 26 DRU-2 and 26 DRU-7

[0291] 52 DRU-3: Combination of 26 DRU-3 and 26 DRU-8

[0292] 52 DRU-4: Combination of 26 DRU-4 and 26 DRU-9

[0293] 106 DRU Index

[0294] The 106 DRUs can be configured as a combination of i) two 52 DRUs and ii) two null tones ±{122, 69}. For example, the null tone can be used as a data tone, and can be defined as follows to maximize tonal distribution. The null tones may not overlap with each other between DRUs.

[0295] For example, when a DRU is defined at a low 20 MHz, null tones of {-191, -190, -57, -56} may be used. Also, when a DRU is defined at a high 20 MHz, null tones of {26, 57, 190, 191} may be used. For example, when a mapping rule between a DRU and an RRU is defined, the null tone used in the RRU mapped to the DRU may be used. As another example, four null tones may be defined in order as null-1, null-2, null-3, and null-4, and null-1 and null-3 may be assigned to one DRU, and null-2 and null-4 may be assigned to the other 106 DRUs.

[0296] - 106 DRU-1: i) 52 DRU-1, 52 DRU-3 and ii) two null tone combinations

[0297] - 106 DRU-2: i) 52 DRU-2, 52 DRU-4 and ii) two null tone combinations

[0298] The following describes the configuration of the tone index of each DRU when DRUs are applied within each 20 MHz in a bandwidth of 80 MHz or more.

[0299] Example 1-2-1: Tone index at each 20 MHz within 80 MHz

[0300] - Tone index of each 20 MHz within the first 40 MHz of 80 MHz: "DRU tone index of each 20 MHz defined in 40 MHz described in Example 1-2" - 256

[0301] - Tone index of each 20 MHz within the second 40 MHz of 80 MHz: "DRU tone index of each 20 MHz defined in 40 MHz described in Example 1-2" + 256

[0302] Example 1-2-2: Tone index at each 20 MHz within 160 MHz

[0303] - Tone index of each 20 MHz within the first 80 MHz of 160 MHz: "DRU tone index of each 20 MHz defined in 80 MHz described in Example 1-2-1" - 512

[0304] - Tone index of each 20 MHz within the second 80 MHz of 160 MHz: "DRU tone index of each 20 MHz defined in 80 MHz described in Example 1-2-1" + 512

[0305] Example 1-2-3: Tone index at each 20 MHz within 240 MHz

[0306] - Tone index of each 20 MHz within the first 80 MHz of 240 MHz: "DRU tone index of each 20 MHz defined in 80 MHz described in Example 1-2-1" - 1024

[0307] - Tone index of each 20 MHz within the second 80 MHz of 240 MHz: "DRU tone index of each 20 MHz defined in 80 MHz described in Example 1-2-1"

[0308] - Tone index of each 20 MHz within the third 80 MHz of 240 MHz: "DRU tone index of each 20 MHz defined in 80 MHz described in Example 1-2-1" + 1024

[0309] Example 1-2-4: Tone index at each 20 MHz within 320 MHz

[0310] - Tone index of each 20 MHz within the first 160 MHz of 320 MHz: "DRU tone index of each 20 MHz defined in 160 MHz described in Example 1-2-2" - 1024

[0311] - Tone index of each 20 MHz within the second 160 MHz of 320 MHz: "DRU tone index of each 20 MHz defined in 160 MHz described in Example 1-2-2" + 1024

[0312] Example 1-2-5: Tone index at each 20 MHz within 480 MHz

[0313] - Tone index of each 20 MHz within the first 160 MHz of 480 MHz: "DRU tone index of each 20 MHz defined in 160 MHz described in Example 1-2-2" - 2048

[0314] - Tone index of each 20 MHz within the second 160 MHz of 480 MHz: "DRU tone index of each 20 MHz defined in 160 MHz described in Example 1-2-2"

[0315] - Tone index of each 20 MHz within the third 160 MHz of 480 MHz: "DRU tone index of each 20 MHz defined in 160 MHz described in Example 1-2-2" + 2048

[0316] Example 1-2-6: Tone index at each 20 MHz within 640 MHz

[0317] - Tone index of each 20 MHz within the first 320 MHz of 640 MHz: "DRU tone index of each 20 MHz defined in 320 MHz described in Example 1-2-4" - 2048

[0318] - Tone index of each 20 MHz within the second 320 MHz of 640 MHz: "DRU tone index of each 20 MHz defined in 320 MHz described in Example 1-2-4" + 2048

[0319] Example 2

[0320] In one embodiment of the present disclosure, when transmitting a PPDU of 40 MHz or more, if a 20 MHz DRU tone plan having a 20 MHz distributed bandwidth is applied to a specific 20 MHz channel, only one of the methods according to Embodiment 1-1 and the methods according to Embodiment 1-2 may be used as the tone plan. Embodiment 2 relates to information indicating one of the methods according to Embodiment 1-1 and the methods according to Embodiment 1-2 (e.g., information regarding the 20 MHz DRU tone plan method) and a signaling method of the information.

[0321] At least one or a combination of the methods according to each of Embodiment 2-1, Embodiment 2-2, Embodiment 2-3, Embodiment 2-4, Embodiment 2-5 and Embodiment 2-6 may be applied.

[0322] Example 2-1

[0323] As an example of the present disclosure, in the MU PPDU situation of DL OFDMA transmission, one of the methods according to Embodiment 1-1 or the methods according to Embodiment 1-2 may be indicated through a common field of the U-SIG field or the UHR-SIG field (e.g., a 1-bit indication field / information included in the common field). That is, information indicating one of the methods according to Embodiment 1-1 or the methods according to Embodiment 1-2 may be included in the common field.

[0324] Information indicating one of the methods according to Embodiment 1-1 or the methods according to Embodiment 1-2 may be independently / differently configured / transmitted for each specific channel unit (e.g., 20, 40, 80, 160 and / or 320 MHz). That is, if a 20 MHz DRU tone plan is applied to a specific 20 MHz channel within each channel unit, information indicating one of the methods according to Embodiment 1-1 or the methods according to Embodiment 1-2 may indicate a tone plan method for each channel.

[0325] Example 2-2

[0326] In one embodiment of the present disclosure, when there are multiple 20 MHz channels to which a 20 MHz DRU tone plan is applied within a specific channel unit, a bitmap may be used to which information indicating either the method according to embodiment 1-1 or the method according to embodiment 1-2 is mapped.

[0327] For example, each bit included in the bitmap may be mapped / set to a value to indicate either the method according to Embodiment 1-1 or the method according to Embodiment 1-2 for each 20 MHz channel. Information related to the 20 MHz channel with the lowest frequency may be mapped to the first bit of the bitmap, and information related to the 20 MHz channel with the highest frequency may be mapped to the last bit. In other words, the bitmap may include bits indicating one of the methods according to Embodiment 1-1 / 1-2 for each frequency size.

[0328] The above bitmap may be included in, but is not limited to, the common field of the U-SIG field or the UHR-SIG field of the PPDU, and may also be included in the UHR-SIG user (information) field, etc.

[0329] Example 2-3

[0330] In one embodiment of the present disclosure, information (e.g., 1 bit of information) for indicating either the method according to Embodiment 1-1 or the method according to Embodiment 1-2 may be transmitted via the user (information) field of the UHR-SIG. As an example, the user field corresponding to each RU in a 20 MHz channel to which the 20 MHz DRU tone plan is applied may include information for indicating either the method according to Embodiment 1-1 or the method according to Embodiment 1-2.

[0331] However, information about the 20 MHz DRU tone plan mode may be valid only when DL OFDMA-based transmission is performed in an MU PPDU situation and conditions are met for applying the 20 MHz DRU tone plan to PPDUs above 40 MHz (e.g., when DRU is applied to a specific 80 MHz channel and the 20 MHz channel is punctured). Otherwise, fields related to information about the 20 MHz DRU tone plan mode may be reserved (or, disregarded or validated) or used for other purposes.

[0332] Example 2-4

[0333] In one embodiment of the present disclosure, a trigger frame soliciting a TB PPDU includes a UHR variant common information field or a UHR variant special user information field, and each of the UHR variant common information field and the UHR variant special user information field may include information for indicating one of the methods according to embodiment 1-1 or the methods according to embodiment 1-2.

[0334] For example, information for indicating one of the methods according to Embodiment 1-1 or the methods according to Embodiment 1-2 may be mapped / included on at least one of specific bits of the UHR variant common information field (e.g., the 23rd bit (B22), the 27th bit (B26), the 54th bit (B53), the 57th bit (B56) to the 64th bit (B63)). The specific bit of the UHR variant common information field may correspond to a reserved bit of the EHT variant common information field.

[0335] As another example, information for indicating either the method according to embodiment 1-1 or the method according to embodiment 1-2 may be included / mapped on the trigger dependent common information field of the UHR variant common information field.

[0336] Based on information indicating one of the methods according to Embodiment 1-1 or Embodiment 1-2 included in the trigger frame, the STA may determine a 20 MHz DRU tone plan to be applied to the TB PPDU. Then, the STA may generate and transmit the TB PPDU according to the determined 20 MHz DRU tone plan.

[0337] As another example of the present disclosure, information for indicating one of the method according to embodiment 1-1 or the method according to embodiment 1-2 may be included / mapped on one of the characteristic bits (e.g., the 38th bit (B37) to the 40th bit (B39)) of the UHR variant special user information field included in the trigger frame. The specific bit of the UHR variant special user information field may correspond to a reserved bit of the EHT variant special user information field.

[0338] As another example, information for indicating one of the methods according to embodiment 1-1 or the method according to embodiment 1-2 may be included in the trigger dependent user information field of the UHR special user information field included in the trigger frame.

[0339] Information indicating one of the methods according to Embodiment 1-1 or the methods according to Embodiment 1-2 may be independently / differently configured / transmitted for each specific channel unit (e.g., 20, 40, 80, 160 and / or 320 MHz). That is, if a 20 MHz DRU tone plan is applied to a specific 20 MHz channel within each channel unit, information indicating one of the methods according to Embodiment 1-1 or the methods according to Embodiment 1-2 may indicate a tone plan method for each channel.

[0340] In one embodiment of the present disclosure, when there are multiple 20 MHz channels to which a 20 MHz DRU tone plan is applied within a specific channel unit, a bitmap may be used to which information indicating either the method according to embodiment 1-1 or the method according to embodiment 1-2 is mapped.

[0341] For example, each bit included in the bitmap may be mapped / set to a value to indicate either the method according to Embodiment 1-1 or the method according to Embodiment 1-2 for each 20 MHz channel. Information related to the 20 MHz channel with the lowest frequency may be mapped to the first bit of the bitmap, and information related to the 20 MHz channel with the highest frequency may be mapped to the last bit. In other words, the bitmap may include bits indicating one of the methods according to Embodiment 1-1 / 1-2 for each frequency size.

[0342] The above bitmap may be included in the UHR variant common information field or the UHR variant special user information field of the above-described trigger frame.

[0343] Additionally or alternatively, information (e.g., 1-bit information) for indicating one of the methods according to Embodiment 1-1 or the methods according to Embodiment 1-2 may be included on the UHR variant user information field of the trigger frame. For example, information for indicating one of the methods according to Embodiment 1-1 or the methods according to Embodiment 1-2 may be included on the UHR variant user information field having an RU allocation subfield value for allocating each RU within a 20 MHz channel to which a 20 MHz DRU tone plan is applied.

[0344] For example, the 26th bit (B25) of the UHR variant user information field and the trigger dependent user information subfield may include information indicating either the method according to embodiment 1-1 or the method according to embodiment 1-2. The 26th bit (B25) of the UHR variant user information field may correspond to a reserved bit of the EHT variant user information field.

[0345] In one embodiment of the present disclosure, when the trigger frame indicates that the bandwidth of the TB PPDU is 40 MHz or more and that a 20 MHz DRU tone plan can be applied (e.g., when the DRU is applied to a specific 80 MHz channel and the 20 MHz channel is punctured), information indicating one of the methods according to the above-described embodiment 1-1 or the method according to the embodiment 1-2 may be valid.

[0346] In other cases (e.g., when the bandwidth of the TB PPDU is indicated to be less than 40 MHz, or when the 20 MHz DRU tone plan is not applied, etc.), the bits containing / mapped with information for indicating either the method according to Embodiment 1-1 or the method according to Embodiment 1-2 may be reserved (or ignored or validated) or used for other purposes.

[0347] According to the above-described method, in a situation where a PPDU of 40 MHz or more is transmitted using a DRU, a 20 MHz DRU tone plan with a 20 MHz distributed bandwidth applied to a specific 20 MHz channel can be more efficiently indicated. An STA can generate and transmit a PPDU to which a 20 MHz DRU tone plan with a 20 MHz distributed bandwidth is applied according to the indicated method, thereby improving coverage and throughput related to PPDU transmission.

[0348] FIG. 15 is a diagram illustrating a PPDU transmission and reception procedure between a transmitting STA and a receiving STA according to one embodiment of the present disclosure. Some of the steps shown in FIG. 15 may be omitted depending on circumstances and / or settings. The transmitting device and the receiving STA may be APs and / or non-AP STAs.

[0349] The transmitting STA may obtain control information related to the aforementioned tone plan (or RU / DRU) (S105). The control information related to the tone plan may include the size and location of the RU, control information related to the RU, information about the frequency band in which the RU is included, information about the STA receiving the RU, etc.

[0350] The transmitting STA may configure / generate a PPDU based on the acquired control information (S110). Configuring / generating a PPDU may mean configuring / generating each field of the PPDU. That is, the step of configuring / generating a PPDU may include a step of configuring U-SIG and UHR-SIG-A / B / C fields that contain control information regarding a tone plan.

[0351] That is, the step of configuring / generating a PPDU may include a step of configuring a field including control information (e.g., N bitmap) indicating the size / position of the RU and / or a step of configuring a field including an identifier (e.g., AID) of an STA receiving the RU.

[0352] Additionally, the step of configuring / generating a PPDU may include a step of generating an STF / LTF sequence to be transmitted via a specific RU. The STF / LTF sequence may be generated based on a preset STF generation sequence / LTF generation sequence.

[0353] Additionally, the step of constructing / generating a PPDU may include a step of generating a data field (i.e., an MPDU) to be transmitted via a specific RU.

[0354] The transmitting STA can transmit the configured / generated PPDU to the receiving STA (S115).

[0355] Specifically, the transmitting STA can perform at least one of cyclic shift diversity (CSD), spatial mapping, inverse discrete Fourier transform (IDFT) / inverse fast Fourier transform (IFFT) operation, and guard interval (GI) insertion operation.

[0356] The receiving STA can decode the PPDU and obtain control information related to the tone-plan (or RU) (S120).

[0357] Specifically, the receiving STA can decode the L-SIG and U-SIG / UHR-SIG of the PPDU based on the L-STF / LTF, and obtain information included in the L-SIG and U-SIG, UHR-SIG fields. Information about various tone plans (i.e., RUs) of the present disclosure can be included in the U-SIG / UHR-SIG (UHR-SIG-A / B / C, etc.), and the receiving STA can obtain information about the tone plan (i.e., RU) through the EHT-SIG.

[0358] The receiving STA can decode the remaining portion of the PPDU based on the information about the acquired tone plan (i.e., RU) (S125). For example, the receiving STA can decode the STF / LTF field of the PPDU based on the information about the tone plan (i.e., RU). In addition, the receiving STA can decode the data field of the PPDU based on the information about the tone plan (i.e., RU) and obtain the MPDU included in the data field.

[0359] Additionally, the receiving STA may perform a processing operation to forward the decoded data to a higher layer (e.g., the MAC layer). Furthermore, if the higher layer instructs the PHY layer to generate a signal in response to the data forwarded to the higher layer, the receiving STA may perform a subsequent operation.

[0360] The embodiments described above are combinations of components and features of the present disclosure in a predetermined form. Each component or feature should be considered optional unless explicitly stated otherwise. Each component or feature may be implemented without being combined with other components or features. Furthermore, it is also possible to form embodiments of the present disclosure by combining some components and / or features. The order of operations described in the embodiments of the present disclosure may be changed. Some components or features of one embodiment may be included in another embodiment or may be replaced with corresponding components or features of another embodiment. It is self-evident that claims that do not have an explicit citation relationship in the patent claims may be combined to form embodiments or incorporated as new claims through post-application amendments.

[0361] It will be apparent to those skilled in the art that the present disclosure may be embodied in other specific forms without departing from the essential characteristics thereof. Therefore, the above detailed description should not be construed as limiting in any respect, but rather as illustrative. The scope of the present disclosure should be determined by a reasonable interpretation of the appended claims, and all modifications within the scope of equivalents of the present disclosure are intended to be included within the scope of the present disclosure.

[0362] The scope of the present disclosure includes software or machine-executable instructions (e.g., an operating system, an application, firmware, a program, etc.) that cause operations according to the methods of various embodiments to be executed on a device or a computer, and a non-transitory computer-readable medium having such software or instructions stored thereon and executable on the device or computer. Instructions that can be used to program a processing system to perform the features described in the present disclosure can be stored on / in a storage medium or a computer-readable storage medium, and a computer program product including such a storage medium can be used to implement the features described in the present disclosure. The storage medium can include, but is not limited to, high-speed random access memory, such as DRAM, SRAM, DDR RAM, or other random access solid state memory devices, and can include non-volatile memory, such as one or more magnetic 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 remotely located from the processor(s). The memory or, alternatively, the non-volatile memory device(s) within the memory comprise a non-transitory computer-readable storage medium. The features described in this disclosure may be incorporated into software and / or firmware stored on any of the machine-readable media, which may control the hardware of the processing system and allow the processing system to interact with other mechanisms that utilize results according to embodiments of the present disclosure. Such software or firmware may include, but is not limited to, application code, device drivers, operating systems, and execution environments / containers.

[0363] The method proposed in this disclosure is described with a focus on examples applied to IEEE 802.11-based systems, but can be applied to various wireless LANs or wireless communication systems in addition to IEEE 802.11-based systems.

Claims

1. A step of receiving, by a first station (STA), a trigger frame including first information about a first bandwidth related to a physical layer protocol data unit (PPDU) from a second STA; and A step of transmitting the PPDU from the first STA to the second STA within the first bandwidth based on the trigger frame, A method wherein the trigger frame includes second information related to the type of a tone plan for the 20 MHz DRU, based on the application of a 20 MHz distributed resource unit (DRU) to at least one unit bandwidth included in the first bandwidth.

2. In paragraph 1, A method wherein the size of the first bandwidth indicated by the first information is 40 MHz or more.

3. In paragraph 1, A method according to claim 1, wherein the second information relating to the type of tone plan for the 20 MHz DRU comprises information relating to one of: i) a tone plan for the first 20 MHz DRU based on a predefined first resource unit (RU) tone plan for a 20 MHz channel, or ii) a tone plan for the second 20 MHz DRU based on a tone plan corresponding to a specific 20 MHz channel among the predefined second RU tone plans for a 40 MHz channel.

4. In paragraph 3, A method wherein the specific 20 MHz channel is one of a first 20 MHz channel having a higher frequency among the 40 MHz channels or a second 20 MHz channel having a lower frequency among the 40 MHz channels.

5. In paragraph 3, A method wherein, based on the second information, a specific tone plan is applied by the first STA to the at least one unit bandwidth, based on i) a tone plan for the first 20 MHz DRU or ii) a tone plan for the second 20 MHz DRU.

6. In paragraph 5, wherein said specific tone plan applied to each of said at least one unit bandwidth has a shift value applied on i) the tone plan for said first 20 MHz DRU or ii) the tone plan for said second 20 MHz DRU, A method wherein the shift value is determined based on the position of at least one unit bandwidth.

7. In paragraph 1, The above trigger frame includes a common information field and a special user information field, A method in which the second information is set to one of i) the 23rd bit (B22), the 27th bit (B26), the 54th bit (B53), the 57th bit (B56) to the 64th bit (B63) of the common information field or ii) the 38th bit (B37) to the 40th bit (B39) of the special user information field.

8. In paragraph 1, The trigger frame includes at least one user information field, A method wherein a specific user information field including an RU allocation subfield related to the 20 MHz DRU tone plan among the at least one user information field includes the second information.

9. In paragraph 1, The above PPDU includes a U(universal)-SIG(signal) field or a UHR(ultra-high reliability)-SIG field, A method wherein the U-SIG field or the UHR-SIG field includes third information about the type of tone plan for the 20 MHz DRU applied to the PPDU.

10. In paragraph 1, A method wherein the second information comprises a bitmap related to the type of tone plan for the 20 MHz DRU applied to the at least one unit bandwidth.

11. In paragraph 6, The size of each of the above at least one unit bandwidth is 20 MHz, Based on the first bandwidth being 40 MHz and the first 20 MHz DRU tone plan being applied by the second information: The specific tone plan of the first unit bandwidth among the first bandwidths is a tone plan to which the shift value of -128 is applied to the first 20 MHz DRU tone plan; and A method wherein the specific tone plan of the second unit bandwidth among the first bandwidths is a tone plan to which the shift value of +128 is applied to the first 20 MHz DRU tone plan.

12. In paragraph 1, The above first STA is a non-access point (AP) STA, The above second STA is an AP.

13. In the first STA, the first STA: one or more transmitters and receivers; and comprising one or more processors connected to said one or more transceivers, One or more of the above processors: Receiving a trigger frame from a second STA through the one or more transceivers, the trigger frame including first information about a first bandwidth related to a physical layer protocol data unit (PPDU); and Based on the trigger frame, the PPDU is set to be transmitted to the second STA through the one or more transceivers within the first bandwidth, A first STA, wherein the trigger frame includes second information related to a type of a tone plan for the 20 MHz DRU, based on the application of a 20 MHz distributed resource unit (DRU) to at least one unit bandwidth included in the first bandwidth.

14. A step of transmitting a trigger frame including first information about a first bandwidth related to a physical layer protocol data unit (PPDU) by a second station (STA) to a first STA; and A step of receiving the PPDU from the first STA by the second STA within the first bandwidth based on the trigger frame, A method wherein the trigger frame includes second information related to the type of a tone plan for the 20 MHz DRU, based on the application of a 20 MHz distributed resource unit (DRU) to at least one unit bandwidth included in the first bandwidth.

15. In the second station (STA), the second STA: one or more transmitters and receivers; and comprising one or more processors connected to said one or more transceivers, One or more of the above processors: Transmitting a trigger frame including first information about a first bandwidth related to a physical layer protocol data unit (PPDU) to a first STA via the one or more transceivers; and Based on the trigger frame, the PPDU is set to be received from the first STA through the one or more transceivers within the first bandwidth, A second STA, wherein the trigger frame includes second information related to a type of a tone plan for the 20 MHz DRU, based on the application of a 20 MHz distributed resource unit (DRU) to at least one unit bandwidth included in the first bandwidth.

16. In a processing device configured to control a first station (STA) in a wireless local area network (WLAN) system, the processing device: one or more processors; and A processing device comprising one or more computer memories operatively connected to said one or more processors and storing instructions that, when executed by said one or more processors, perform a method according to any one of claims 1 to 12.

17. One or more non-transitory computer-readable media storing one or more instructions, A computer-readable medium, wherein the one or more commands are executed by one or more processors to control a device in a wireless LAN system to perform a method according to any one of claims 1 to 12.

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