METHOD AND APPARATUS FOR PERFORMING PREAMBLE-PUNCTURING-BASED COMMUNICATION IN WIRELESS LAN SYSTEM

Abstract

A method and an apparatus operating in a wireless LAN system are disclosed. A method performed by a first STA in a wireless LAN system, according to one embodiment of the present disclosure, may comprise the steps of: generating a PPDU including a first U-SIG field related to a first bandwidth and a second U-SIG field related to a second bandwidth; and transmitting, to a second STA, the PPDU including the first U-SIG field and the second U-SIG field, wherein the first U-SIG field may include a first punctured channel information field indicating a first puncturing pattern from among a plurality of puncturing patterns corresponding to the first bandwidth, and the second U-SIG field may include a second punctured channel information field indicating a second puncturing pattern from among a plurality of puncturing patterns corresponding to the second bandwidth.

Description

TECHNICAL FIELD

The present disclosure relates to a communication operation in a wireless local area network (WLAN) system, and more specifically, to a method and device for performing communication based on preamble puncturing in a next-generation wireless LAN system.

BACKGROUND ART

New technologies for improving transmission rates, increasing bandwidth, improving reliability, reducing errors, and reducing latency have been introduced for a wireless LAN (WLAN). Among WLAN technologies, an Institute of Electrical and Electronics Engineers (IEEE) 802.11 series standard may be referred to as Wi-Fi. For example, technologies recently introduced to WLAN include enhancements for Very High-Throughput (VHT) of the 802.11ac standard, and enhancements for High Efficiency (HE) of the IEEE 802.11 ax standard.

In order to provide a more improved wireless communication environment, an enhancement technologies for EHT (Extremely High Throughput) are being discussed. For example, technologies for multiple access point (AP) coordination and multiple input multiple output (MIMO) supporting an increased bandwidth, efficient utilization of multiple bands and increased spatial streams are being studied, and, in particular, various technologies for supporting low latency or real-time traffic are being studied. Furthermore, new technologies are being discussed to support ultra-high reliability (UHR), including improvements or extensions of EHT technology.

SUMMARY

The technical problem of the present disclosure is to provide a method and device for performing communication based on preamble puncturing in a wireless LAN system.

An additional technical problem of the present disclosure is to provide a method and device for indicating a preamble puncturing pattern in a 480 MHz/640 MHz band in a wireless LAN system.

The technical objects to be achieved by the present disclosure are not limited to the above-described technical objects, and other technical objects which are not described herein will be clearly understood by those skilled in the pertinent art from the following description.

A method for performing communication by a first station (STA) in a wireless LAN system according to one aspect of the present disclosure may include generating a Physical layer Protocol Data Unit (PPDU) including a first U (universal)-signal (SIG) field associated with a first bandwidth and a second U-SIG field associated with a second bandwidth; and transmitting the PPDU including the first U-SIG field and the second U-SIG field to a second STA, and the first U-SIG field may include a first punctured channel information field indicating a first puncturing pattern among a plurality of puncturing patterns corresponding to the first bandwidth, and the second U-SIG field may include a second punctured channel information field indicating a second puncturing pattern among a plurality of puncturing patterns corresponding to the second bandwidth.

A method for performing communication by a second station (STA) in a wireless LAN system according to an additional aspect of the present disclosure may include transmitting, to the first STA, information related to a total bandwidth for PPDU (physical layer protocol data unit) transmission; and receiving, from the first STA, the PPDU including a first U-SIG field related to a first bandwidth among the total bandwidth and a second U-SIG field related to a second bandwidth among the total bandwidth, and the first U-SIG field may include a first punctured channel information field indicating a first puncturing pattern among a plurality of puncturing patterns corresponding to the first bandwidth, and the second U-SIG field may include a second punctured channel information field indicating a second puncturing pattern among a plurality of puncturing patterns corresponding to the second bandwidth.

According to various embodiments of the present disclosure, a method and device for performing communication based on preamble puncturing in a wireless LAN system can be provided.

According to various embodiments of the present disclosure, a method and device for indicating a preamble puncturing pattern in a 480 MHz/640 MHz band in a wireless LAN system may be provided.

According to various embodiments of the present disclosure, efficiency and throughput can be improved as preamble puncturing-based communication is supported in a wider bandwidth.

Effects achievable by the present disclosure are not limited to the above-described effects, and other effects which are not described herein may be clearly understood by those skilled in the pertinent art from the following description.

BRIEF DESCRIPTION OF THE DRAWINGS

Accompanying drawings included as part of detailed description for understanding the present disclosure provide embodiments of the present disclosure and describe technical features of the present disclosure with detailed description.

FIG. 1 illustrates a block configuration diagram of a wireless communication device according to an embodiment of the present disclosure.

FIG. 2 is a diagram illustrating an exemplary structure of a WLAN system to which the present disclosure may be applied.

FIG. 3 is a diagram for describing a link setup process to which the present disclosure may be applied.

FIG. 4 is a diagram for describing a backoff process to which the present disclosure may be applied.

FIG. 5 is a diagram for describing a frame transmission operation based on CSMA/CA to which the present disclosure may be applied.

FIG. 6 is a diagram for describing an example of a frame structure used in a WLAN system to which the present disclosure may be applied.

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

FIGS. 8 to 10 are diagrams for describing examples of resource units of a WLAN system to which the present disclosure may be applied.

FIG. 11 illustrates an example structure of a HE-SIG-B field.

FIG. 12 is a diagram for describing a MU-MIMO method in which a plurality of users/STAs are allocated to one RU.

FIG. 13 illustrates an example of a PPDU format to which the present disclosure may be applied.

FIG. 14 illustrates an example of a trigger frame format to which the present disclosure may be applied.

FIG. 15 is a diagram for explaining an operation performed by a first STA according to an embodiment of the present disclosure.

FIG. 16 is a diagram for explaining an operation performed by a second STA according to an embodiment of the present disclosure.

FIG. 17 is a diagram for explaining a PPDU transmission and reception procedure between a transmitting STA and a receiving STA according to an embodiment of the present disclosure.

DETAILED DESCRIPTION

Hereinafter, embodiments according to the present disclosure will be described in detail by referring to accompanying drawings. Detailed description to be disclosed with accompanying drawings is to describe exemplary embodiments of the present disclosure and is not to represent the only embodiment that the present disclosure may be implemented. The following detailed description includes specific details to provide complete understanding of the present disclosure. However, those skilled in the pertinent art knows that the present disclosure may be implemented without such specific details.

In some cases, known structures and devices may be omitted or may be shown in a form of a block diagram based on a core function of each structure and device in order to prevent a concept of the present disclosure from being ambiguous.

In the present disclosure, when an element is referred to as being “connected”, “combined” or “linked” to another element, it may include an indirect connection relation that yet another element presents therebetween as well as a direct connection relation. In addition, in the present disclosure, a term, “include” or “have”, specifies the presence of a mentioned feature, step, operation, component and/or element, but it does not exclude the presence or addition of one or more other features, stages, operations, components, elements and/or their groups.

In the present disclosure, a term such as “first”, “second”, etc. is used only to distinguish one element from other element and is not used to limit elements, and unless otherwise specified, it does not limit an order or importance, etc. between elements. Accordingly, within a scope of the present disclosure, a first element in an embodiment may be referred to as a second element in another embodiment and likewise, a second element in an embodiment may be referred to as a first element in another embodiment.

A term used in the present disclosure is to describe a specific embodiment, and is not to limit a claim. As used in a described and attached claim of an embodiment, a singular form is intended to include a plural form, unless the context clearly indicates otherwise. A term used in the present disclosure, “and/or”, may refer to one of related enumerated items or it means that it refers to and includes any and all possible combinations of two or more of them. In addition, “/” between words in the present disclosure has the same meaning as “and/or”, unless otherwise described.

Examples of the present disclosure may be applied to various wireless communication systems. For example, examples of the present disclosure may be applied to a wireless LAN system. For example, examples of the present disclosure may be applied to an IEEE 802.11a/g/n/ac/ax standards-based wireless LAN. Furthermore, examples of the present disclosure may be applied to a wireless LAN based on the newly proposed IEEE 802.11be (or EHT) standard. Examples of the present disclosure may be applied to an IEEE 802.11be Release-2 standard-based wireless LAN corresponding to an additional enhancement technology of the IEEE 802.11be Release-1 standard. Additionally, examples of the present disclosure may be applied to a next-generation standards-based wireless LAN after IEEE 802.11be. Further, examples of this disclosure may be applied to a cellular wireless communication system. For example, it may be applied to a cellular wireless communication system based on Long Term Evolution (LTE)-based technology and 5G New Radio (NR)-based technology of the 3rd Generation Partnership Project (3GPP) standard.

Hereinafter, technical features to which examples of the present disclosure may be applied will be described.

FIG. 1 illustrates a block diagram of a wireless communication device according to an embodiment of the present disclosure.

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 Wireless Transmit Receive Unit (WTRU), an User Equipment (UE), a Mobile Station (MS), an user terminal (UT), a Mobile Subscriber Station (MSS), a Mobile Subscriber Unit (MSU), a subscriber station (SS), an advanced mobile station (AMS), a wireless terminal (WT), or simply user, etc. In addition, the first device 100 and the second device 200 include an access point (AP), a base station (BS), a fixed station, a Node B, a base transceiver system (BTS), a network, it may be replaced with various terms such as an Artificial Intelligence (AI) system, a road side unit (RSU), a repeater, a router, a relay, and a gateway.

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

Referring to FIG. 1, the first device 100 and the second device 200 may transmit and receive radio signals through various wireless LAN technologies (e.g., IEEE 802.11 series). The first device 100 and the second device 200 may include an interface for a medium access control (MAC) layer and a physical layer (PHY) conforming to the IEEE 802.11 standard.

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.) technologies other than wireless LAN technology. In addition, the device of the present disclosure may be implemented in various devices such as a mobile phone, a vehicle, a personal computer, augmented reality (AR) equipment, and virtual reality (VR) equipment, etc. In addition, the STA of the present specification may support various communication services such as a voice call, a video call, data communication, autonomous-driving, machine-type communication (MTC), machine-to-machine (M2M), device-to-device (D2D), IoT (Internet-of-Things), etc.

A first device 100 may include one or more processors 102 and one or more memories 104 and may additionally include one or more transceivers 106 and/or one or more antennas 108. A processor 102 may control a memory 104 and/or a transceiver 106 and may be configured to implement description, functions, procedures, proposals, methods and/or operation flow charts disclosed in the present disclosure. For example, a processor 102 may transmit a wireless signal including first information/signal through a transceiver 106 after generating first information/signal by processing information in a memory 104. In addition, a processor 102 may receive a wireless signal including second information/signal through a transceiver 106 and then store information obtained by signal processing of second information/signal in a memory 104. A memory 104 may be connected to a processor 102 and may store a variety of information related to an operation of a processor 102. For example, a memory 104 may store a software code including instructions for performing all or part of processes controlled by a processor 102 or for performing description, functions, procedures, proposals, methods and/or operation flow charts disclosed in the present disclosure. Here, a processor 102 and a memory 104 may be part of a communication modem/circuit/chip designed to implement a wireless LAN technology (e.g., IEEE 802.11 series). A transceiver 106 may be connected to a processor 102 and may transmit and/or receive a wireless signal through one or more antennas 108. A transceiver 106 may include a transmitter and/or a receiver. A transceiver 106 may be used together with a RF (Radio Frequency) unit. In the present disclosure, a device may mean a communication modem/circuit/chip.

A second device 200 may include one or more processors 202 and one or more memories 204 and may additionally include one or more transceivers 206 and/or one or more antennas 208. A processor 202 may control a memory 204 and/or a transceiver 206 and may be configured to implement description, functions, procedures, proposals, methods and/or operation flows charts disclosed in the present disclosure. For example, a processor 202 may generate third information/signal by processing information in a memory 204, and then transmit a wireless signal including third information/signal through a transceiver 206. In addition, a processor 202 may receive a wireless signal including fourth information/signal through a transceiver 206, and then store information obtained by signal processing of fourth information/signal in a memory 204. A memory 204 may be connected to a processor 202 and may store a variety of information related to an operation of a processor 202. For example, a memory 204 may store a software code including instructions for performing all or part of processes controlled by a processor 202 or for performing description, functions, procedures, proposals, methods and/or operation flow charts disclosed in the present disclosure. Here, a processor 202 and a memory 204 may be part of a communication modem/circuit/chip designed to implement a wireless LAN technology (e.g., IEEE 802.11 series). A transceiver 206 may be connected to a processor 202 and may transmit and/or receive a wireless signal through one or more antennas 208. A transceiver 206 may include a transmitter and/or a receiver. A transceiver 206 may be used together with a RF unit. In the present disclosure, a device may mean a communication modem/circuit/chip.

Hereinafter, a hardware element of a device 100, 200 will be described in more detail. It is not limited thereto, but 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., a functional layer such as PHY, MAC). One or more processors 102, 202 may generate one or more PDUs (Protocol Data Unit) and/or one or more SDUs (Service Data Unit) according to description, functions, procedures, proposals, methods and/or operation flow charts disclosed in the present disclosure. One or more processors 102, 202 may generate a message, control information, data or information according to description, functions, procedures, proposals, methods and/or operation flow charts disclosed in the present disclosure. One or more processors 102, 202 may generate a signal (e.g., a baseband signal) including a PDU, a SDU, a message, control information, data or information according to functions, procedures, proposals and/or methods disclosed in the present disclosure to provide it to one or more transceivers 106, 206. One or more processors 102, 202 may receive a signal (e.g., a baseband signal) from one or more transceivers 106, 206 and obtain a PDU, a SDU, a message, control information, data or information according to description, functions, procedures, proposals, methods and/or operation flow charts disclosed in the present disclosure.

One or more processors 102, 202 may be referred to as a controller, a micro controller, a micro processor or a micro computer. One or more processors 102, 202 may be implemented by a hardware, a firmware, a software, or their combination. In an example, one or more ASICs (Application Specific Integrated Circuit), one or more DSPs (Digital Signal Processor), one or more DSPDs (Digital Signal Processing Device), one or more PLDs (Programmable Logic Device) or one or more FPGAs (Field Programmable Gate Arrays) may be included in one or more processors 102, 202. Description, functions, procedures, proposals, methods and/or operation flow charts disclosed in the present disclosure may be implemented by using a firmware or a software and a firmware or a software may be implemented to include a module, a procedure, a function, etc. A firmware or a software configured to perform description, functions, procedures, proposals, methods and/or operation flow charts disclosed in the present disclosure may be included in one or more processors 102, 202 or may be stored in one or more memories 104, 204 and driven by one or more processors 102, 202. Description, functions, procedures, proposals, methods and/or operation flow charts disclosed in the present disclosure may be implemented by using a firmware or a software in a form of a code, an instruction and/or a set of instructions.

One or more memories 104, 204 may be connected to one or more processors 102, 202 and may store data, a signal, a message, information, a program, a code, an indication and/or an instruction in various forms. One or more memories 104, 204 may be configured with ROM, RAM, EPROM, a flash memory, a hard drive, a register, a cash memory, a computer readable storage medium and/or their combination. One or more memories 104, 204 may be positioned inside and/or outside one or more processors 102, 202. In addition, one or more memories 104, 204 may be connected to one or more processors 102, 202 through a variety of technologies such as a wire or wireless connection.

One or more transceivers 106, 206 may transmit user data, control information, a wireless signal/channel, etc. mentioned in methods and/or operation flow charts, etc. of the present disclosure to one or more other devices. One or more transceivers 106, 206 may receiver user data, control information, a wireless signal/channel, etc. mentioned in description, functions, procedures, proposals, methods and/or operation flow charts, etc. disclosed in the present disclosure from one or more other devices. For example, one or more transceivers 106, 206 may be connected to one or more processors 102, 202 and may transmit and receive a wireless signal. For example, one or more processors 102, 202 may control one or more transceivers 106, 206 to transmit user data, control information or a wireless signal to one or more other devices. In addition, one or more processors 102, 202 may control one or more transceivers 106, 206 to receive user data, control information or a wireless signal from one or more other devices. In addition, one or more transceivers 106, 206 may be connected 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, a wireless signal/channel, etc. mentioned in description, functions, procedures, proposals, methods and/or operation flow charts, etc. disclosed in the present disclosure through one or more antennas 108, 208. In the present disclosure, one or more antennas may be a plurality of physical antennas or a plurality of logical antennas (e.g., an antenna port). One or more transceivers 106, 206 may convert a received wireless signal/channel, etc. into a baseband signal from a RF band signal to process received user data, control information, wireless signal/channel, etc. by using one or more processors 102, 202. One or more transceivers 106, 206 may convert user data, control information, a wireless signal/channel, etc. which are processed by using one or more processors 102, 202 from a baseband signal to a RF band signal. Therefore, one or more transceivers 106, 206 may include an (analogue) oscillator and/or a filter.

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

Hereinafter, downlink (DL) may mean a link for communication from an AP STA to a non-AP STA, and a DL PPDU/packet/signal may be transmitted and received through the DL. In DL communication, a transmitter may be part of an AP STA, and a receiver may be part of a non-AP STA. Uplink (UL) may mean a link for communication from non-AP STAs to AP STAs, and a UL PPDU/packet/signal may be transmitted and received through the UL. In UL communication, a transmitter may be part of a non-AP STA, and a receiver may be part of an AP STA.

FIG. 2 is a diagram illustrating an exemplary structure of a wireless LAN system to which the present disclosure may be applied.

The structure of the wireless LAN system may consist of be composed of a plurality of components. A wireless LAN supporting STA mobility transparent to an upper layer may be provided by interaction of a plurality of components. A Basic Service Set (BSS) corresponds to a basic construction block of a wireless LAN. FIG. 2 exemplarily shows that two BSSs (BSS1 and BSS2) exist and two STAs are included as members of each BSS (STA1 and STA2 are included in BSS1, and STA3 and STA4 are included in BSS2). An ellipse representing a BSS in FIG. 2 may also be understood as representing a coverage area in which STAs included in the corresponding BSS maintain communication. This area may be referred to as a Basic Service Area (BSA). When an STA moves out of the BSA, it may not directly communicate with other STAs within the BSA.

If the DS shown in FIG. 2 is not considered, the most basic type of BSS in a wireless

LAN is an independent BSS (IBSS). For example, IBSS may have a minimal form containing only two STAs. For example, assuming that other components are omitted, BSS1 containing only STA1 and STA2 or BSS2 containing only STA3 and STA4 may respectively correspond to representative examples of IBSS. This configuration is possible when STAs may communicate directly without an AP. In addition, in this type of wireless LAN, it is not configured in advance, but may be configured when a LAN is required, and this may be referred to as an ad-hoc network. Since the IBSS does not include an AP, there is no centralized management entity. That is, in IBSS, STAs are managed in a distributed manner. In IBSS, all STAs may be made up of mobile STAs, and access to the distributed system (DS) is not allowed, forming a self-contained network.

Membership of an STA in the BSS may be dynamically changed by turning on or off the STA, entering or exiting the BSS area, and the like. To become a member of the BSS, the STA may join the BSS using a synchronization process. In order to access all services of the BSS infrastructure, the STA shall be associated with the BSS. This association may be dynamically established and may include the use of a Distribution System Service (DSS).

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

DS means a structure in which BSSs are interconnected. Specifically, as shown in FIG. 2, a BSS may exist as an extended form of a network composed of a plurality of BSSs. DS is a logical concept and may be specified by the characteristics of Distributed System Media (DSM). In this regard, a wireless medium (WM) and a DSM may be logically separated. Each logical medium is used for a different purpose and is used by different components. These medium are not limited to being the same, nor are they limited to being different. In this way, the flexibility of the wireless LAN structure (DS structure or other network structure) may be explained in that a plurality of media are logically different. That is, the wireless LAN structure may be implemented in various ways, and the corresponding wireless LAN structure may be independently specified by the physical characteristics of each embodiment.

A DS may support a mobile device by providing seamless integration of a plurality of BSSs and providing logical services necessary to address an address to a destination. In addition, the DS may further include a component called a portal that serves as a bridge for connection between the wireless LAN and other networks (e.g., IEEE 802.X).

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

Data transmitted from one of the STA(s) associated with an AP to a STA address of the corresponding AP may be always received on an uncontrolled port and may be processed by an IEEE 802.1X port access entity. In addition, when a controlled port is authenticated, transmission data (or frames) may be delivered to the DS.

In addition to the structure of the DS described above, an extended service set (ESS) may be configured to provide wide coverage.

An ESS means a network in which a network having an arbitrary size and complexity is composed of DSs and BSSs. The ESS may correspond to a set of BSSs connected to one DS. However, the ESS does not include the DS. An ESS network is characterized by being seen as an IBSS in the Logical Link Control (LLC) layer. STAs included in the ESS may communicate with each other, and mobile STAs may move from one BSS to another BSS (within the same ESS) transparently to the LLC. APs included in one ESS may have the same service set identification (SSID). The SSID is distinguished from the BSSID, which is an identifier of the BSS.

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

FIG. 3 is a diagram for explaining a link setup process to which the present disclosure may be applied.

In order for an STA to set up a link with respect to a network and transmit/receive data, it first discovers a network, performs authentication, establishes an association, and need to perform the authentication process for security. The link setup process may also be referred to as a session initiation process or a session setup process. In addition, the processes of discovery, authentication, association, and security setting of the link setup process may be collectively referred to as an association process.

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

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

Although not shown in FIG. 3, the scanning operation may be performed in a passive scanning manner. In passive scanning, a STA performing scanning waits for a beacon frame while moving channels. The beacon frame is one of the management frames defined in IEEE 802.11, and is periodically transmitted to notify the existence of a wireless network and to allow the STA performing scanning to find a wireless network and participate in the wireless network. In the BSS, the AP serves to transmit beacon frames periodically, and in the IBSS, STAs within the IBSS rotate to transmit beacon frames.

When the STA performing scanning receives a beacon frame, the STA stores information for the BSS included in the beacon frame and records beacon frame information in each channel while moving to another channel. The STA receiving the beacon frame may store BSS-related information included in the received beacon frame, move to the next channel, and perform scanning in the next channel in the same way. Comparing active scanning and passive scanning, active scanning has an advantage of having less delay and less power consumption than passive scanning.

After the STA discovers the network, an authentication process may be performed in step S320. This authentication process may be referred to as a first authentication process in order to be clearly distinguished from the security setup operation of step S340 to be described later.

The authentication process includes a process in which the STA transmits an authentication request frame to the AP, and in response to this, the AP transmits an authentication response frame to the STA. An authentication frame used for authentication request/response corresponds to a management frame.

The authentication frame includes an authentication algorithm number, an authentication transaction sequence number, a status code, a challenge text, a robust security network (RSN), and a Finite Cyclic Group, etc. This corresponds to some examples of information that may be included in the authentication request/response frame, and may be replaced with other information or additional information may be further included.

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

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.

For example, the association request frame may include information related to various capabilities, a beacon listen interval, a service set identifier (SSID), supported rates, supported channels, RSN, mobility domain, supported operating classes, Traffic Indication Map Broadcast request (TIM broadcast request), interworking service capability, etc. For example, the association response frame may include information related to various capabilities, status code, association ID (AID), supported rates, enhanced distributed channel access (EDCA) parameter set, received channel power indicator (RCPI), received signal to noise indicator (RSNI), mobility domain, timeout interval (e.g., association comeback time), overlapping BSS scan parameters, TIM broadcast response, Quality of Service (QOS) map, etc. This corresponds to some examples of information that may be included in the association request/response frame, and may be replaced with other information or additional information may be further included.

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

The security setup process of step S340 may include, for example, a process of setting up a private key through 4-way handshaking through an Extensible Authentication Protocol over LAN (EAPOL) frame. In addition, the security setup process may be performed according to a security scheme not defined in the IEEE 802.11 standard.

FIG. 4 is a diagram for explaining a backoff process to which the present disclosure may be applied.

In the wireless LAN system, a basic access mechanism of medium access control (MAC) is a carrier sense multiple access with collision avoidance (CSMA/CA) mechanism. The CSMA/CA mechanism is also called Distributed Coordination Function (DCF) of IEEE 802.11 MAC, and basically adopts a “listen before talk” access mechanism. According to this type of access mechanism, the AP and/or STA may perform Clear Channel Assessment (CCA) sensing a radio channel or medium during a predetermined time interval (e.g., DCF Inter-Frame Space (DIFS)), prior to starting transmission. As a result of the sensing, if it is determined that the medium is in an idle state, frame transmission is started through the corresponding medium. On the other hand, if it is detected that the medium is occupied or busy, the corresponding AP and/or STA does not start its own transmission and may set a delay period for medium access (e.g., a random backoff period) and attempt frame transmission after waiting. By applying the random backoff period, since it is expected that several STAs attempt frame transmission after waiting for different periods of time, collision may be minimized.

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

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

When the random backoff process starts, the STA continuously monitors the medium while counting down the backoff slots according to the determined backoff count value. When the medium is monitored for occupancy, it stops counting down and waits, and resumes the rest of the countdown when the medium becomes idle.

In the example of FIG. 4, when a packet to be transmitted arrives at the MAC of STA3, STA3 may transmit the frame immediately after confirming that the medium is idle as much as DIFS. The remaining STAs monitor and wait for the medium to be occupied/busy. In the meantime, data to be transmitted may also occur in each of STA1, STA2, and STA5, and each STA waits as long as DIFS when the medium is monitored as idle, and then may perform a countdown of the backoff slot according to the random backoff count value selected by each STA. Assume that STA2 selects the smallest backoff count value and STA1 selects the largest backoff count value. That is, the case where the remaining back-off time of STA5 is shorter than the remaining back-off time of STA1 at the time when STA2 completes the back-off count and starts frame transmission is exemplified. STA1 and STA5 temporarily stop counting down and wait while STA2 occupies the medium. When the occupation of STA2 ends and the medium becomes idle again, STA1 and STA5 wait for DIFS and resume the stopped backoff count. That is, frame transmission may be started after counting down the remaining backoff slots for the remaining backoff time. Since the remaining backoff time of STA5 is shorter than that of STA1, STA5 starts frame transmission. While STA2 occupies the medium, data to be transmitted may also occur in STA4. From the standpoint of STA4, when the medium becomes idle, STA4 may wait for DIFS, and then may perform a countdown according to the random backoff count value selected by the STA4 and start transmitting frames. The example of FIG. 4 shows a case where the remaining backoff time of STA5 coincides with the random backoff count value of STA4 by chance. In this case, a collision may occur between STA4 and STA5. When a collision occurs, both STA4 and STA5 do not receive an ACK, so data transmission fails. In this case, STA4 and STA5 may double the CW value, select a random backoff count value, and perform a countdown. STA1 waits while the medium is occupied due to transmission of STA4 and STA5, waits for DIFS when the medium becomes idle, and then starts frame transmission after the remaining backoff time has elapsed.

As in the example of FIG. 4, the data frame is a frame used for transmission of data forwarded to a higher layer, and may be transmitted after a backoff performed after DIFS elapses from when the medium becomes idle. Additionally, the management frame is a frame used for exchange of management information that is not forwarded to a higher layer, and is transmitted after a backoff performed after an IFS such as DIFS or Point Coordination Function IFS (PIFS). As a subtype frames of management frame, there are a Beacon, an association request/response, a re-association request/response, a probe request/response, an authentication request/response, etc. A control frame is a frame used to control access to a medium. As a subtype frames of control frame, there are Request-To-Send (RTS), Clear-To-Send (CTS), Acknowledgement (ACK), Power Save-Poll (PS-Poll), block ACK (BlockAck), block ACK request (BlockACKReq), null data packet announcement (NDP announcement), and trigger, etc. If the control frame is not a response frame of the previous frame, it is transmitted after backoff performed after DIFS elapses, and if it is a response frame of the previous frame, it is transmitted without performing backoff after short IFS (SIFS) elapses. The type and subtype of the frame may be identified by a type field and a subtype field in a frame control (FC) field.

A Quality of Service (QOS) STA may perform the backoff that is performed after an arbitration IFS (AIFS) for an access category (AC) to which the frame belongs, that is, AIFS[i] (where i is a value determined by AC), and then may transmit the frame. Here, the frame in which AIFS[i] can be used may be a data frame, a management frame, or a control frame other than a response frame.

FIG. 5 is a diagram for explaining a frame transmission operation based on CSMA/CA to which the present disclosure may be applied.

As described above, the CSMA/CA mechanism includes virtual carrier sensing in addition to physical carrier sensing in which a STA directly senses a medium. Virtual carrier sensing is intended to compensate for problems that may occur in medium access, such as a hidden node problem. For virtual carrier sensing, the MAC of the STA may use a Network Allocation Vector (NAV). The NAV is a value indicating, to other STAs, the remaining time until the medium is available for use by an STA currently using or having the right to use the medium. Therefore, the value set as NAV corresponds to a period in which the medium is scheduled to be used by the STA transmitting the frame, and the STA receiving the NAV value is prohibited from accessing the medium during the corresponding period. For example, the NAV may be configured based on the value of the “duration” field of the MAC header of the frame.

In the example of FIG. 5, it is assumed that a STA1 intends to transmit data to a STA2, and a STA3 is in a position capable of overhearing some or all of frames transmitted and received between the STA1 and the STA2.

In order to reduce the possibility of collision of transmissions of multiple STAs in CSMA/CA based frame transmission operation, a mechanism using RTS/CTS frames may be applied. In the example of FIG. 5, while transmission of the STA1 is being performed, as a result of carrier sensing of the STA3, it may be determined that the medium is in an idle state. That is, the STA1 may correspond to a hidden node to the STA3. Alternatively, in the example of FIG. 5, it may be determined that the carrier sensing result medium of the STA3 is in an idle state while transmission of the STA2 is being performed. That is, the STA2 may correspond to a hidden node to the STA3. Through the exchange of RTS/CTS frames before performing data transmission and reception between the STA1 and the STA2, a STA outside the transmission range of one of the STA1 or the STA2, or a STA outside the carrier sensing range for transmission from the STA1 or the STA3 may not attempt to occupy the channel during data transmission and reception between the STA1 and the STA2.

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

The STA1 may transmit an RTS frame to the STA2 after performing a backoff when the channel is in an idle state during DIFS. When the STA2 receives the RTS frame, the STA2 may transmit a CTS frame as a response to the RTS frame to the STA1 after SIFS.

If the STA3 cannot overhear the CTS frame from the STA2 but can overhear the RTS frame from the STA1, the STA3 may set a NAV timer for a frame transmission period (e.g., SIFS+CTS frame+SIFS+data frame+SIFS+ACK frame) that is continuously transmitted thereafter, using the duration information included in the RTS frame. Alternatively, if the STA3 can overhear a CTS frame from the STA2 although the STA3 cannot overhear an RTS frame from the STA1, the STA3 may set a NAV timer for a frame transmission period (e.g., SIFS+data frame+SIFS+ACK frame) that is continuously transmitted thereafter, using the duration information included in the CTS frame. That is, if the STA3 can overhear one or more of the RTS or CTS frames from one or more of the STA1 or the STA2, the STA3 may set the NAV accordingly. When the STA3 receives a new frame before the NAV timer expires, the STA3 may update the NAV timer using duration information included in the new frame. The STA3 does not attempt channel access until the NAV timer expires.

When the STA1 receives the CTS frame from the STA2, the STA1 may transmit the data frame to the STA2 after SIFS from the time point when the reception of the CTS frame is completed. When the STA2 successfully receives the data frame, the STA2 may transmit an ACK frame as a response to the data frame to the STA1 after SIFS. The STA3 may determine whether the channel is being used through carrier sensing when the NAV timer expires. When the STA3 determines that the channel is not used by other terminals during DIFS after expiration of the NAV timer, the STA3 may attempt channel access after a contention window (CW) according to a random backoff has passed.

FIG. 6 is a diagram for explaining an example of a frame structure used in a WLAN system to which the present disclosure may be applied.

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

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

A basic PPDU frame 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-High Throughput (HT)) PPDU frame format may consist of only L-STF (Legacy-STF), L-LTF (Legacy-LTF), SIG field, and data field. In addition, depending on the type of PPDU frame format (e.g., HT-mixed format PPDU, HT-greenfield format PPDU, VHT (Very High Throughput) PPDU, etc.), an additional (or different type) STF, LTF, and SIG fields may be included between the SIG field and the data field (this will be described later with reference to FIG. 7).

The STF is a signal for signal detection, automatic gain control (AGC), diversity selection, precise time synchronization, and the like, and the LTF is a signal for channel estimation and frequency error estimation. The STF and LTF may be referred to as signals for synchronization and channel estimation of the OFDM physical layer.

The SIG field may include a RATE field and a LENGTH field. The RATE field may include information on modulation and coding rates of data. The LENGTH field may include information on the length of data. Additionally, the SIG field may include a parity bit, a SIG TAIL bit, and the like.

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

A MAC PDU is defined according to various MAC frame formats, and a basic MAC frame consists of a MAC header, a frame body, and a Frame Check Sequence (FCS). The MAC frame may consist of MAC PDUs and be transmitted/received through the PSDU of the data part of the PPDU frame format.

The MAC header includes a Frame Control field, a Duration/ID field, an Address field, and the like. 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 a corresponding frame or the like. For details of the Sequence Control, QoS Control, and HT Control subfields of the MAC header, refer to the IEEE 802.11 standard document.

A null-data packet (NDP) frame format means a frame format that does not include a data packet. That is, the NDP frame refers to a frame format that includes a physical layer convergence procedure (PLCP) header part (i.e., STF, LTF, and SIG fields) in a general PPDU frame format and does not include the remaining parts (i.e., data field). A NDP frame may also be referred to as a short frame format.

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

In standards such as IEEE 802.11a/g/n/ac/ax, various types of PPDUs have been used. The basic PPDU format (IEEE 802.11a/g) includes L-LTF, L-STF, L-SIG and Data fields. The basic PPDU format may also be referred to as a non-HT PPDU format.

The HT PPDU format (IEEE 802.11n) additionally includes HT-SIG, HT-STF, and HT-LFT(s) fields to the basic PPDU format. The HT PPDU format shown in FIG. 7 may be referred to as an HT-mixed format. In addition, an HT-greenfield format PPDU may be defined, and this corresponds to a format consisting of HT-GF-STF, HT-LTF1, HT-SIG, one or more HT-LTF, and Data field, not including L-STF, L-LTF, and L-SIG (not shown).

An example of the VHT PPDU format (IEEE 802.11ac) additionally includes VHT SIG-A, VHT-STF, VHT-LTF, and VHT-SIG-B fields to the basic PPDU format.

An example of the HE PPDU format (IEEE 802.11ax) additionally includes Repeated L-SIG (RL-SIG), HE-SIG-A, HE-SIG-B, HE-STF, HE-LTF(s), Packet Extension (PE) field to the basic PPDU format. Some fields may be excluded or their length may vary according to detailed examples of the HE PPDU format. For example, the HE-SIG-B field is included in the HE PPDU format for multi-user (MU), and the HE-SIG-B is not included in the HE PPDU format for single user (SU). 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 8 us. The Extended Range (HE ER) SU PPDU format does not include the HE-SIG-B field, and the length of the HE-SIG-A field may vary to 16 us.

FIGS. 8 to 10 are diagrams for explaining examples of resource units of a WLAN system to which the present disclosure may be applied.

Referring to FIGS. 8 to 10, a resource unit (RU) defined in a wireless LAN system will be described. the RU may include a plurality of subcarriers (or tones). The RU may be used when transmitting signals to multiple STAs based on the OFDMA scheme. In addition, the RU may be defined even when a signal is transmitted to one STA. The RU may be used for STF, LTF, data field of the PPDU, etc.

As shown in FIGS. 8 to 10, RUs corresponding to different numbers of tones (i.e., subcarriers) are used to construct some fields of 20 MHz, 40 MHz, or 80 MHz X-PPDUs (X is HE, EHT, etc.). For example, resources may be allocated in RU units shown for the X-STF, X-LTF, and Data field.

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

As shown at the top of FIG. 8, 26-units (i.e., units corresponding to 26 tones) may be allocated. 6 tones may be used as a guard band in the leftmost band of the 20 MHz band, and 5 tones may be used as a guard band in the rightmost band of the 20 MHz band. In addition, 7 DC tones are inserted in the center band, that is, the DC band, and 26-units corresponding to each of the 13 tones may exist on the left and right sides of the DC band. In addition, 26-unit, 52-unit, and 106-unit may be allocated to other bands. Each unit may be allocated for STAs or users.

The RU allocation of FIG. 8 is utilized not only in a situation for multiple users (MU) but also in a situation for a single user (SU), and in this case, it is possible to use one 242-unit as shown at the bottom of FIG. 8. In this case, three DC tones may be inserted.

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

FIG. 9 is a diagram illustrating an exemplary allocation of resource units (RUs) used on a 40 MHz band.

Just as RUs of various sizes are used in the example of FIG. 8, 26-RU, 52-RU, 106-RU, 242-RU, 484-RU, and the like may be used in the example of FIG. 9 as well. In addition, 5 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.

In addition, as shown, when used for a single user, a 484-RU may be used.

FIG. 10 is a diagram illustrating an exemplary allocation of resource units (RUs) used on an 80 MHz band.

Just as RUs of various sizes are used in the example of FIG. 8 and FIG. 9, 26-RU, 52-RU, 106-RU, 242-RU, 484-RU, 996-RU and the like may be used in the example of FIG. 10 as well. In addition, in the case of an 80 MHz PPDU, RU allocation of HE PPDUs and EHT PPDUs may be different, and the example of FIG. 10 shows an example of RU allocation for 80 MHz EHT PPDUs. The scheme that 12 tones are used as a guard band in the leftmost band of the 80 MHz band and 11 tones are used as a guard band in the rightmost band of the 80 MHz band in the example of FIG. 10 is the same in HE PPDU and EHT PPDU. Unlike HE PPDU, where 7 DC tones are inserted in the DC band and there is one 26-RU corresponding to each of the 13 tones on the left and right sides of the DC band, in the EHT PPDU, 23 DC tones are inserted into the DC band, and one 26-RU exists on the left and right sides of the DC band. Unlike the HE PPDU, where one null subcarrier exists between 242-RUs rather than the center band, there are five null subcarriers in the EHT PPDU. In the HE PPDU, one 484-RU does not include null subcarriers, but in the EHT PPDU, one 484-RU includes 5 null subcarriers.

In addition, as shown, when used for a single user, 996-RU may be used, and in this case, 5 DC tones are inserted in common with HE PPDU and EHT PPDU.

EHT PPDUs over 160 MHz may be configured with a plurality of 80 MHz subblocks in FIG. 10. The RU allocation for each 80 MHz subblock may be the same as that of the 80 MHZ EHT PPDU of FIG. 10. If the 80 MHz subblock of the 160 MHz or 320 MHz EHT PPDU is not punctured and the entire 80 MHz subblock is used as part of RU or multiple RU (MRU), the 80 MHz subblock may use 996-RU of FIG. 10.

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

When an 80 MHz subblock includes RUs smaller than 996 tones, or parts of the 80 MHz subblock are punctured, the 80 MHz subblock may use RU allocation other than the 996-tone RU.

The RU of the present disclosure may be used for uplink (UL) and/or downlink (DL) communication. For example, when trigger-based UL-MU communication is performed, the STA transmitting the trigger (e.g., AP) may allocate a first RU (e.g., 26/52/106/242-RU, etc.) to a first STA and allocate a second RU (e.g., 26/52/106/242-RU, etc.) to a second STA, through trigger information (e.g., trigger frame or triggered response scheduling (TRS)). Thereafter, the first STA may transmit a first trigger-based (TB) PPDU based on the first RU, and the second STA may transmit a second TB PPDU based on the second RU. The first/second TB PPDUs may be transmitted to the AP in the same time period.

For example, when a DL MU PPDU is configured, the STA transmitting the DL MU PPDU (e.g., AP) may allocate a first RU (e.g., 26/52/106/242-RU, etc.) to a first STA and allocate a second RU (e.g., 26/52/106/242-RU, etc.) to a second STA. That is, the transmitting STA (e.g., AP) may transmit the HE-STF, HE-LTF, and Data fields for the first STA through the first RU within one MU PPDU, and may transmit the HE-STF, HE-LTF, and Data fields for the second STA through the second RU.

Information on the allocation of RUs may be signaled through HE-SIG-B in the HE PPDU format.

FIG. 11 illustrates an example structure of a HE-SIG-B field.

As shown, the HE-SIG-B field may include a common field and a user-specific field. If HE-SIG-B compression is applied (e.g., full-bandwidth MU-MIMO transmission), the common field may not be included in HE-SIG-B, and the HE-SIG-B content channel may include only a user-specific field. If HE-SIG-B compression is not applied, the common field may be included in HE-SIG-B.

The common field may include information on RU allocation (e.g., RU assignment, RUs allocated for MU-MIMO, the number of MU-MIMO users (STAs), etc.)

The common field may include N*8 RU allocation subfields. Here, N is the number of subfields, N=1 in the case of 20 or 40 MHz MU PPDU, N=2 in the case of 80 MHz MU PPDU, N=4 in the case of 160 MHz or 80+80 MHz MU PPDU, etc. One 8-bit RU allocation subfield may indicate the size (26, 52, 106, etc.) and frequency location (or RU index) of RUs included in the 20 MHz band.

For example, if a value of the 8-bit RU allocation subfield is 00000000, it may indicate that nine 26-RUs are sequentially allocated in order from the leftmost to the rightmost in the example of FIG. 8, if the value is 00000001, it may indicate that seven 26-RUs and one 52-RU are sequentially allocated in order from leftmost to rightest, and if the value is 00000010, it may indicate that five 26-RUs, one 52-RU, and two 26-RUs are sequentially allocated from the leftmost side to the rightmost side.

As an additional example, if the value of the 8-bit RU allocation subfield is 01000y2y1y0, it may indicate that one 106-RU and five 26-RUs are sequentially allocated from the leftmost to the rightmost in the example of FIG. 8. In this case, multiple users/STAs may be allocated to the 106-RU in the MU-MIMO scheme. Specifically, up to 8 users/STAs may be allocated to the 106-RU, and the number of users/STAs allocated to the 106-RU is determined based on 3-bit information (i.e., y2y1y0). For example, when the 3-bit information (y2y1y0) corresponds to a decimal value N, the number of users/STAs allocated to the 106-RU may be N+1.

Basically, one user/STA may be allocated to each of a plurality of RUs, and different users/STAs may be allocated to different RUs. For RUs larger than a predetermined size (e.g., 106, 242, 484, 996-tones, . . . ), a plurality of users/STAs may be allocated to one RU, and MU-MIMO scheme may be applied for the plurality of users/STAs.

The set of user-specific fields includes information on how all users (STAs) of the corresponding PPDU decode their payloads. User-specific fields may contain zero or more user block fields. The non-final user block field includes two user fields (i.e., information to be used for decoding in two STAs). The final user block field contains one or two user fields. The number of user fields may be indicated by the RU allocation subfield of HE-SIG-B, the number of symbols of HE-SIG-B, or the MU-MIMO user field of HE-SIG-A. A User-specific field may be encoded separately from or independently of a common field.

FIG. 12 is a diagram for explaining a MU-MIMO method in which a plurality of users/STAs are allocated to one RU.

In the example of FIG. 12, it is assumed that the value of the RU allocation subfield is 01000010. This corresponds to the case where y2y1y0=010 in 01000y2y1y0. 010 corresponds to 2 in decimal (i.e., N=2) and may indicate that 3 (=N+1) users are allocated to one RU. In this case, one 106-RU and five 26-RUs may be sequentially allocated from the leftmost side to the rightmost side of a specific 20 MHz band/channel. Three users/STAs may be allocated to the 106-RU in a MU-MIMO manner. As a result, a total of 8 users/STAs are allocated to the 20 MHz band/channel, and the user-specific field of HE-SIG-B may include 8 user fields (i.e., 4 user block fields). Eight user fields may be assigned to RUs as shown in FIG. 12.

The user field may be constructed based on two formats. The user field for a MU-MIMO allocation may be constructed with a first format, and the user field for non-MU-MIMO allocation may be constructed with a second format. Referring to the example of FIG. 12, user fields 1 to 3 may be based on the first format, and user fields 4 to 8 may be based on the second format. The first format and the second format may contain bit information of the same length (e.g., 21 bits).

The user field of the first format (i.e., format for MU-MIMO allocation) may be constructed as follows. For example, out of all 21 bits of one user field, B0-B10 includes the user's identification information (e.g., STA-ID, AID, partial AID, etc.), B11-14 includes spatial configuration information such as the number of spatial streams for the corresponding user, B15-B18 includes Modulation and Coding Scheme (MCS) information applied to the Data field of the corresponding PPDU, B19 is defined as a reserved field, and B20 may include information on a coding type (e.g., binary convolutional coding (BCC) or low-density parity check (LDPC)) applied to the Data field of the corresponding PPDU.

The user field of the second format (i.e., the format for non-MU-MIMO allocation) may be constructed as follows. For example, out of all 21 bits of one user field, B0-B10 includes the user's identification information (e.g., STA-ID, AID, partial AID, etc.), B11-13 includes information on the number of spatial streams (NSTS) applied to the corresponding RU, B14 includes information indicating whether beamforming is performed (or whether a beamforming steering matrix is applied), B15-B18 includes Modulation and Coding Scheme (MCS) information applied to the Data field of the corresponding PPDU, B19 includes information indicating whether DCM (dual carrier modulation) is applied, and B20 may include information on a coding type (e.g., BCC or LDPC) applied to the Data field of the corresponding PPDU.

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

FIG. 13 illustrates an example of a PPDU format to which the present disclosure may be applied.

The PPDU of FIG. 13 may be referred as various names such as an EHT PPDU, a transmitted PPDU, a received PPDU, a first type or an Nth type PPDU. For example, the PPDU or EHT PPDU of the present disclosure may be referred as various names such as a transmission PPDU, a reception PPDU, a first type or an Nth type PPDU. In addition, the EHT PPU may be used in an EHT system and/or a new wireless LAN system in which the EHT system is improved.

The EHT MU PPDU of FIG. 13 corresponds to a PPDU carrying one or more data (or PSDUs) for one or more users. That is, the EHT MU PPDU may be used for both SU transmission and MU transmission. For example, the EHT MU PPDU may correspond to a PPDU for one receiving STA or a plurality of receiving STAs.

In the EHT TB PPDU of FIG. 13, the EHT-SIG is omitted compared to the EHT MU PPDU. Upon receiving a trigger for UL MU transmission (e.g., a trigger frame or TRS), the STA may perform UL transmission based on the EHT TB PPDU format.

In the example of the EHT PPDU format of FIG. 13, L-STF to EHT-LTF correspond to a preamble or a physical preamble, and may be generated/transmitted/received/acquired/decoded in the physical layer.

A Subcarrier frequency spacing of L-STF, L-LTF, L-SIG, RL-SIG, Universal SIGNAL (U-SIG), EHT-SIG field (these are referred to as pre-EHT modulated fields) may be set to 312.5 kHz. A subcarrier frequency spacing of the EHT-STF, EHT-LTF, Data, and PE field (these are referred to as EHT modulated fields) may be set to 78.125 kHz. That is, the tone/subcarrier index of L-STF, L-LTF, L-SIG, RL-SIG, U-SIG, and EHT-SIG field may be indicated in units of 312.5 kHz, and the tone/subcarrier index of EHT-STF, EHT-LTF, Data, and PE field may be indicated in units of 78.125 kHz.

The L-LTF and L-STF of FIG. 13 may be constructed identically to the corresponding fields of the PPDU described in FIGS. 6 to 7.

The L-SIG field of FIG. 13 may be constructed with 24 bits and may be used to communicate rate and length information. For example, the L-SIG field includes 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 may be included. For example, the 12-bit Length field may include information on a time duration or a length of the PPDU. For example, a value of the 12-bit Length field may be determined based on the type of 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 the HE PPDU, the value of the Length field may be determined as a multiple of 3+1 or a multiple of 3+2.

For example, the transmitting STA may apply BCC encoding based on a coding rate of 1/2 to 24-bit information of the L-SIG field. Thereafter, the transmitting STA may obtain 48-bit BCC coded bits. BPSK modulation may be applied to 48-bit coded bits to generate 48 BPSK symbols. The transmitting STA may map 48 BPSK symbols to any location except for a pilot subcarrier (e.g., {subcarrier index −21, −7, +7, +21}) and a DC subcarrier (e.g., {subcarrier index 0}). As a result, 48 BPSK symbols may be mapped to subcarrier indices −26 to −22, −20 to −8, −6 to −1, +1 to +6, +8 to +20, and +22 to +26. The transmitting STA may additionally map the signals of {−1, −1, −1, 1} to the subcarrier index {−28, −27, +27, +28}. The above signal may be used for channel estimation in the frequency domain corresponding to {−28, −27, +27, +28}.

The transmitting STA may construct RL-SIG which is constructed identically to L-SIG. For RL-SIG, BPSK modulation is applied. The receiving STA may recognize that the received PPDU is a HE PPDU or an EHT PPDU based on the existence of the RL-SIG.

After the RL-SIG of FIG. 13, a Universal SIG (U-SIG) may be inserted. The U-SIG may be referred as various names such as a first SIG field, a first SIG, a first type SIG, a control signal, a control signal field, and a first (type) control signal, etc.

The U-SIG may include N-bit information and may include information for identifying the type of EHT PPDU. For example, U-SIG may be configured based on two symbols (e.g., two consecutive OFDM symbols). Each symbol (e.g., OFDM symbol) for the U-SIG may have a duration of 4 us, and the U-SIG may have a total 8 us duration. Each symbol of the U-SIG may be used to transmit 26 bit information. For example, each symbol of the U-SIG may be transmitted and received based on 52 data tones and 4 pilot tones.

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

For example, the A bit information (e.g., 52 un-coded bits) transmitted by the U-SIG includes a CRC field (e.g., a 4-bit field) and a tail field (e.g., 6 bit-length field). The CRC field and the tail field may be transmitted through the second symbol of the U-SIG. The CRC field may be constructed based on 26 bits allocated to the first symbol of U-SIG and 16 bits remaining except for the CRC/tail field in the second symbol, and may be constructed based on a conventional CRC calculation algorithm. In addition, the tail field may be used to terminate the trellis of the convolution decoder, and for example, the tail field may be set to 0.

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

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

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

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

For example, if the EHT PPDU is classified into various types (e.g., EHT PPDU related to SU mode, EHT PPDU related to MU mode, EHT PPDU related to TB mode, EHT PPDU related to Extended Range transmission, etc.), information on the type of EHT PPDU may be included in the version-dependent bits of the U-SIG.

For example, the U-SIG may include information on 1) a bandwidth field containing information on a bandwidth, 2) a field containing information on a MCS scheme applied to EHT-SIG, 3) an indication field containing information related to whether the DCM technique is applied to the EHT-SIG, 4) a field containing information on the number of symbols used for EHT-SIG, 5) a field containing information on whether EHT-SIG is constructed over all bands, 6) a field containing information on the type of EHT-LTF/STF, and 7) a field indicating the length of EHT-LTF and CP length.

Preamble puncturing may be applied to the PPDU of FIG. 13. Preamble puncturing may mean transmission of a PPDU in which no signal is present in one or more 20 MHz subchannels among the bandwidth of the PPDU. Preamble puncturing may be applied to a PPDU transmitted to one or more users. For example, the resolution of the preamble puncturing may be 20 MHz for an EHT MU PPDU in an OFDMA transmission with a bandwidth greater than 40 MHz and in a non-OFDMA transmission with a bandwidth of 80 MHz and 160 MHz. That is, in the above case, puncturing for a subchannel smaller than 242-tone RU may not be allowed. In addition, for an EHT MU PPDU in a non-OFDMA transmission with a bandwidth of 320 MHz, the resolution of the preamble puncturing may be 40 MHz. That is, puncturing for subchannels smaller than 484-tone RU in 320 MHz bandwidth may not be allowed. Also, preamble puncturing may not be applied for the primary 20 MHz channel in EHT MU PPDU.

Information about preamble puncturing applied to PPDU may be included in U-SIG and/or EHT-SIG. For example, the first field of U-SIG may include information about the contiguous bandwidth of the PPDU, and the second field of U-SIG may include information about preamble puncturing applied to the PPDU.

For example, the U-SIG and the EHT-SIG may include information on preamble puncturing based on the following method. If the bandwidth of the PPDU exceeds 80 MHZ, the U-SIG may be individually constructed in units of 80 MHz. For example, if the bandwidth of the PPDU is 160 MHz, the PPDU may include a first U-SIG for a first 80 MHz band and a second U-SIG for a second 80 MHz band. In this case, the first field of the first U-SIG includes information on the 160 MHz bandwidth, and the second field of the first U-SIG includes information on preamble puncturing applied to the first 80 MHZ band (i.e., information on a preamble puncturing pattern). In addition, the first field of the second U-SIG includes information on a 160 MHz bandwidth, and the second field of the second U-SIG includes information on preamble puncturing applied to a second 80 MHz band (i.e., information on a preamble puncturing pattern). The EHT-SIG following the first U-SIG may include information on preamble puncturing applied to the second 80 MHz band (i.e., information on a preamble puncturing pattern), and the EHT-SIG following the second U-SIG may include information on preamble puncturing applied to the first 80 MHz band (i.e., information on a preamble puncturing pattern).

Additionally or alternatively, the U-SIG and the EHT-SIG may include information on preamble puncturing based on the following method. The U-SIG may include information on preamble puncturing for all bands (i.e., information on a preamble puncturing pattern). That is, EHT-SIG does not include information on preamble puncturing, and only U-SIG may include information on preamble puncturing (i.e., information on a preamble puncturing pattern).

U-SIG may be constructed in units of 20 MHz. For example, if an 80 MHz PPDU is constructed, the U-SIG may be duplicated. That is, the same 4 U-SIGs may be included in the 80 MHz PPDU. PPDUs exceeding 80 MHz bandwidth may include different U-SIGs.

The EHT-SIG of FIG. 13 may include control information for the receiving STA. EHT-SIG may be transmitted through at least one symbol, and one symbol may have a length of 4 us. Information on the number of symbols used for EHT-SIG may be included in U-SIG.

The EHT-SIG may include technical features of HE-SIG-B described through FIGS. 11 and 12. For example, EHT-SIG, like the example of FIG. 8, may include a common field and a user-specific field. The Common field of the EHT-SIG may be omitted, and the number of user-specific fields may be determined based on the number of users.

As in the example of FIG. 11, the common field of the EHT-SIG and the user-specific field of the EHT-SIG may be coded separately. One user block field included in the user-specific field may contain information for two user fields, but the last user block field included in the user-specific field may contain one or two user fields. That is, one user block field of the EHT-SIG may contain up to two user fields. As in the example of FIG. 12, each user field may be related to MU-MIMO allocation or non-MU-MIMO allocation.

In the same way as in the example of FIG. 11, the common field of the EHT-SIG may include a CRC bit and a Tail bit, The length of the CRC bit may be determined as 4 bits, and the length of the tail bit is determined by 6 bits and may be set to 000000.

As in the example of FIG. 11, the common field of the EHT-SIG may include RU allocation information. RU allocation information may mean information on the location of an RU to which a plurality of users (i.e., a plurality of receiving STAs) are allocated. RU allocation information may be configured in units of 9 bits (or N bits).

A mode in which a common field of EHT-SIG is omitted may be supported. The mode in which the common field of the EHT-SIG is omitted may be referred as a compressed mode. When the compressed mode is used, a plurality of users (i.e., a plurality of receiving STAs) of the EHT PPDU may decode the PPDU (e.g., the data field of the PPDU) based on non-OFDMA. That is, a plurality of users of the EHT PPDU may decode a PPDU (e.g., a data field of the PPDU) received through the same frequency band. When a non-compressed mode is used, multiple users of the EHT PPDU may decode the PPDU (e.g., the data field of the PPDU) based on OFDMA. That is, a plurality of users of the EHT PPDU may receive the PPDU (e.g., the data field of the PPDU) through different frequency bands.

EHT-SIG may be configured based on various MCS techniques. As described above, information related to the MCS scheme applied to EHT-SIG may be included in U-SIG. EHT-SIG can be configured based on DCM scheme. DCM scheme may provide an effect similar to frequency diversity, reduce interference, and improve coverage by reusing the same signal on two subcarriers. For example, modulation symbols to which the same modulation scheme is applied can be repeatedly mapped on available tones/subcarriers. For example, among N data tones (e.g., 52 data tones) allocated for EHT-SIG, a modulation symbol (e.g., BPSK modulation symbol) to which a specific modulation scheme is applied may be mapped to the first consecutive half tones (e.g., the 1st to 26th tones), and a modulation symbol (e.g., BPSK modulation symbol) to which the same specific modulation scheme is applied may be mapped to the remaining consecutive half tones (e.g., the 27th to 52nd tones). That is, the modulation symbol mapped to the 1st tone and the modulation symbol mapped to the 27th tone are the same.

As described above, information (e.g., a 1-bit field) related to whether the DCM technique is applied to the EHT-SIG may be included in the U-SIG. The EHT-STF of FIG. 13 may be used to improve automatic gain control (AGC) estimation in a MIMO environment or an OFDMA environment. The EHT-LTF of FIG. 13 may be used to estimate a channel in a MIMO environment or an OFDMA environment.

Information on the type of STF and/or LTF (including information on a guard interval (GI) applied to LTF) may be included in the U-SIG field and/or the EHT-SIG field of FIG. 13.

The PPDU (i.e., EHT PPDU) of FIG. 13 may be constructed based on an example of RU allocation of FIGS. 8 to 10.

For example, a EHT PPDU transmitted on a 20 MHz band, that is, a 20 MHz EHT PPDU may be constructed based on the RU of FIG. 8. That is, a RU location of EHT-STF, EHT-LTF, and data field included in the EHT PPDU may be determined as shown in FIG. 8. A EHT PPDU transmitted on a 40 MHz band, that is, a 40 MHz EHT PPDU may be constructed based on the RU of FIG. 9. That is, a RU location of EHT-STF, EHT-LTF, and data field included in the EHT PPDU may be determined as shown in FIG. 9.

The EHT PPDU transmitted on the 80 MHz band, that is, the 80 MHz EHT PPDU may be constructed based on the RU of FIG. 10. That is, a RU location of EHT-STF, EHT-LTF, and data field included in the EHT PPDU may be determined as shown in FIG. 10. The tone-plan for 80 MHz in FIG. 10 may correspond to two repetitions of the tone-plan for 40 MHz in FIG. 9.

The tone-plan for 160/240/320 MHz may be configured in the form of repeating the pattern of FIG. 9 or 10 several times.

The PPDU of FIG. 13 may be identified as an EHT PPDU based on the following method.

The receiving STA may determine the type of the received PPDU as the EHT PPDU based on the following. For example, when 1) the first symbol after the L-LTF signal of the received PPDU is BPSK, 2) RL-SIG in which the L-SIG of the received PPDU is repeated is detected, and 3) the result of applying the modulo 3 calculation to the value of the Length field of the L-SIG of the received PPDU (i.e., the remainder after dividing by 3) is detected as 0, the received PPDU may be determined as a EHT PPDU. When the received PPDU is determined to be an EHT PPDU, the receiving STA may determine the type of the EHT PPDU based on bit information included in symbols subsequent to the RL-SIG of FIG. 13. In other words, the receiving STA may determine the received PPDU as a EHT PPDU, based on 1) the first symbol after the L-LTF signal, which is BSPK, 2) RL-SIG contiguous to the L-SIG field and identical to the L-SIG, and 3) L-SIG including a Length field in which the result of applying modulo 3 is set to 0.

For example, the receiving STA may determine the type of the received PPDU as the HE PPDU based on the following. For example, when 1) the first symbol after the L-LTF signal is BPSK, 2) RL-SIG in which L-SIG is repeated is detected, and 3) the result of applying modulo 3 to the length value of L-SIG is detected as 1 or 2, the received PPDU may be determined as a HE PPDU.

For example, the receiving STA may determine the type of the received PPDU as non-HT, HT, and VHT PPDU based on the following. For example, when 1) the first symbol after the L-LTF signal is BPSK and 2) RL-SIG in which L-SIG is repeated is not detected, the received PPDU may be determined as non-HT, HT, and VHT PPDU.

In addition, if the receiving STA detects an RL-SIG with repeated L-SIG in the received PPDU, it may be determined that it is a HE PPDU or an EHT PPDU. In this case, if the rate (6 Mbps) check fails, the received PPDU may be determined as a non-HT, HT, or VHT PPDU. If the rate (6 Mbps) check and the parity check pass, if the result of applying modulo 3 to the Length value of the L-SIG is detected as 0, the received PPDU can be determined as an EHT PPDU, and if the result of Length mod 3 is not 0, it may be determined as a HE PPDU.

The PPDU of FIG. 13 may be used to transmit and receive various types of frames.

For example, the PPDU of FIG. 13 may be used for (simultaneous) transmission and reception of one or more of a control frame, a management frame, or a data frame.

Hereinafter, the U-SIG included in the EHT PPDU will be described in more detail.

For a 40 MHz EHT PPDU or Extended Range (ER) preamble, the U-SIG content is the same in both 20 MHz subchannels. For an 80 MHz EHT PPDU or ER preamble, the U-SIG content is the same in all non-punctured 20 MHz subchannels. For a 160/320 MHz EHT PPDU or ER preamble, the U-SIG content is the same on all non-punctured 20 MHz subchannels within each 80 MHz subblock and may be different from the U-SIG content in other 80 MHz subblocks.

The U-SIG-1 part of the U-SIG of an EHT MU PPDU may include PHY version identifier (B0-B2), BW (B3-B5), UL/DL (B6), BSS color (B7-B12), and TXOP (B13-B19), Disregard (B20-B24), and Validate (B25).

And, the U-SIG-2 part of the EHT MU PPDU may include PPDU type and compression mode (B0-B1), validate (B2), punctured channel information (B3-B7), validation (B8), EHT-SIG MCS (B9-B10), number of EHT-SIG symbols (B11-B15), CRC (B16-B19), and tail (B20-B25).

For example, assume that the UL/DL field values are set to 0. When the PPDU Type and Compression Mode (B0-B1) field value of the U-SIG-2 part is 0, this indicates a DL OFDMA transmission. When the PPDU Type and Compression Mode (B0-B1) field value of the U-SIG-2 part is 1, this indicates an EHT SU transmission or an EHT sounding NDP. When the PPDU Type and Compression Mode (B0-B1) field value of the U-SIG-2 part is 2, this indicates a non-OFDMA DL MU-MIMO transmission.

As another example, assume that the UL/DL field value is set to 1. When the PPDU Type and Compression Mode (B0-B1) field value of the U-SIG-2 part is 0, this may indicate a TB PPDU (e.g., UL OFDMA or UL-non-OFDMA). And, when the PPDU Type and Compression Mode (B0-B1) field value of the U-SIG-2 part is 1, this may indicate an EHT SU transmission or an EHT sounding NDP.

Here, an example of 5-bit punctured channel indication for non-OFDMA case in EHT MU PPDU is given in Table 1 below.

TABLE 1
PPDU
bandwidth	Cases	Puncturing pattern	Field value
20/40 MHz	No puncturing	[1 1 1 1]	0
80 MHz	No puncturing	[1 1 1 1]	0
	20 MHz puncturing	[x 1 1 1]	1
		[1 x 1 1]	2
		[1 1 x 1]	3
		[1 1 1 x]	4
160 MHz	No puncturing	[1 1 1 1 1 1 1 1]	0
	20 MHz puncturing	[x 1 1 1 1 1 1 1]	1
		[1 x 1 1 1 1 1 1]	2
		[1 1 x 1 1 1 1 1]	3
		[1 1 1 x 1 1 1 1]	4
		[1 1 1 1 x 1 1 1]	5
		[1 1 1 1 1 x 1 1]	6
		[1 1 1 1 1 1 x 1]	7
		[1 1 1 1 1 1 1 x]	8
	40 MHz puncturing	[x x 1 1 1 1 1 1]	9
		[1 1 x x 1 1 1 1]	10
		[1 1 1 1 x x 1 1]	11
		[1 1 1 1 1 1 x x]	12
320 MHz	No puncturing	[1 1 1 1 1 1 1 1]	0
	40 MHz puncturing	[x 1 1 1 1 1 1 1]	1
		[1 x 1 1 1 1 1 1]	2
		[1 1 x 1 1 1 1 1]	3
		[1 1 1 x 1 1 1 1]	4
		[1 1 1 1 x 1 1 1]	5
		[1 1 1 1 1 x 1 1]	6
		[1 1 1 1 1 1 x 1]	7
		[1 1 1 1 1 1 1 x]	8
	80 MHz puncturing	[x x 1 1 1 1 1 1]	9
		[1 1 x x 1 1 1 1]	10
		[1 1 1 1 x x 1 1]	11
		[1 1 1 1 1 1 x x]	12
	320-80-40	[x x x 1 1 1 1 1]	13
		[x x 1 x 1 1 1 1]	14
		[x x 1 1 x 1 1 1]	15
		[x x 1 1 1 x 1 1]	16
		[x x 1 1 1 1 x 1]	17
		[x x 1 1 1 1 1 x]	18
		[x 1 1 1 1 1 x x]	19
		[1 x 1 1 1 1 x x]	20
		[1 1 x 1 1 1 x x]	21
		[1 1 1 x 1 1 x x]	22
		[1 1 1 1 x 1 x x]	23
		[1 1 1 1 1 x x x]	24

In the puncturing pattern of Table 1, 1 represents a non-punctured subchannel and x represents a punctured subchannel. The puncturing granularity for 80 MHz and 160 MHz PPDU bandwidths may be 20 MHz, and the puncturing granularity for 320 MHz PPDU bandwidth may be 40 MHz.

Next, the U-SIG-1 part of the U-SIG of the EHT TB PPDU may include a version identifier (B0-B2), BW (B3-B5), UL/DL (B6), BSS color (B7-B12), TXOP (B13-B19), and disregard (B20-B25), and the U-SIG-2 part may include a PPDU type and compression mode (B0-B1), validate (B2), spatial reuse 1 (B3-B6), spatial reuse 2 (B7-B10), disregard (B11-B15), CRC (B16-B19), and tail (B20-B25).

As described above, the U-SIG field of the EHT MU PPDU includes 5-bit punctured channel information, but the EHT TB PPDU does not include punctured channel information. This is because the EHT TB PPDU is assumed to be configured according to the resource allocation indicated by the trigger frame or TRS control information, and therefore there is no need for the STA to inform the AP of the resource information of the EHT TB PPDU.

In addition, even if a trigger frame or TRS control information as described above is received, the STA may not respond with a HE TB PPDU. For example, if a non-AP STA has one or more subfields of a common information field included in the trigger frame or a user field addressed to or selected by the non-AP STA that are not recognized, not supported, or have unsatisfied values, the non-AP STA may choose not to respond to the trigger frame. Similarly, if a non-AP STA has a TRS control subfield included in a frame addressed to the non-AP STA that is not recognized, not supported, or have unsatisfied values by the non-AP STA, the non-AP STA may choose not to respond to the TRS control subfield.

FIG. 14 illustrates an example format of a trigger frame to which the present disclosure may be applied.

The trigger frame may allocate resources for transmission of one or more TB PPDUs and request transmission of TB PPDUs. The trigger frame may also include other information required by the STA, which transmits the TB PPDU in response. The trigger frame may include common information and user information list fields in the frame body.

The common info field may include information that is common to one or more TB PPDU transmissions requested by a trigger frame, such as trigger type, UL length, presence of a subsequent trigger frame (e.g., More TF), presence of CS (channel sensing) required, UL BW (bandwidth), etc. FIG. 14 exemplarily shows an EHT variant common information field format.

The trigger type subfield of 4 bits may 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, BFRP (Beamforming Report Poll), MU-BAR (multi user-block acknowledgement request), MU-RTS (multi user-request to send), BSRP (Buffer Status Report Poll), GCR (groupcast with retries) MU-BAR, BQRP (Bandwidth Query Report Poll), and NFRP (NDP Feedback Report Poll), respectively, and the values 8 to 15 are defined as reserved.

Among the common information, the trigger dependent common info subfield may include information that is selectively included based on the trigger type.

A special user info field may be included in the trigger frame. The special user info field does not include user specific information, but rather contains extended common information not provided in the common info field.

The user info list includes zero or more user info fields. FIG. 14 exemplarily shows the EHT variant user info field format.

The AID12 subfield basically indicates that it is a user information field for an STA having 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 info field. The special user info field is a user information field that does not include user specific information but includes extended common information that is not provided in the common information field. For example, the special user info field can be identified by the AID12 value of 2007, and the special user info field flag subfield in the common information field can indicate whether the special user info field is included.

The RU allocation subfield may indicate the size and position of RU/MRU. For this purpose, the RU allocation subfield may be interpreted together with the PS160 (primary/secondary 160 MHz) subfield of the user information field, the UL BW subfield of the common information field, etc. For example, the mapping of B7-B1 of the RU allocation subfield may be defined together with the settings of B0 and PS160 subfields of the RU allocation subfield as shown in Table 2 below. Table 2 shows an example of encoding of the PS160 subfield and the RU allocation subfield of the EHT variant user information field.

TABLE 2
	B0 of the	B7-B1 of
	RU	the RU
PS160	Allocation	Allocation	Bandwidth	RU/MRU		PHY RU/MRU
subfield	subfield	subfield	(MHz)	size	RU/MRU index	index
0-3:	0-8	20, 40, 80,	26	RU1 to RU9,	37 × N + RU
80 MHz segment where the		160, or 320		respectively	index
RU is located	9-17	40, 80, 160,		RU10 to RU18,
		or 320		respectively
	18	80, 160, or		Reserved
		320
	19-36	80, 160, or		RU20 to RU37
		320		respectively
	37-40	20, 40, 80,	52	RU1 to RU4,	16 × N + RU
		160, or 320		respectively	index
	41-44	40, 80, 160,		RU5 to RU8,
		or 320		respectively
	45-52	80, 160, or		RU9 to RU16,
		320		respectively
	53, 54	20, 40, 80,	106	RU1 and RU2,	8 × N + RU
		160, or 320		respectively	index
	55, 56	40, 80, 160,		RU3 and RU4,
		or 320		respectively
	57, 60	80, 160, or		RU5 to RU8,
		320		respectively
	61	20, 40, 80,	242	RU1	4 × N + RU
		160, or 320			index
	62	40, 80, 160,		RU2
		or 320
	63, 64	80, 160, or		RU3 and RU4,
		320		respectively
	65	40, 80, 160,	484	RU1	2 × N + RU
		or 320			index
	66	80, 160, or		RU2
		320
	67	80, 160, or	996	RU1	N + RU
		320			index
0-1:	0	68	Reserved	Reserved
160 MHz	1		160 or 320	2 × 996	RU1	X1 − RU
segment						index
where the
RU is
located
0	0	69	Reserved	Reserved
0	1
1	0
1	1		320	4 × 996	RU1	RU1
0-3:	70-72	20, 40, 80,	52 + 26	MRU1 to MRU3,	12 × N +
80 MHz segment where the		160, or 320		respectively	MRU index
RU is located	73-75	40, 80, 160,	52 + 26	MRU4 to MRU6,
			or 320		respectively
		76-81	80, 160, or	52 + 26	MRU7 to MRU12,
			320		respectively
		82, 83	20, 40, 80,	106 + 26	MRU1 and MRU2,	8 × N +
			160, or 320		respectively	MRU index
		84, 85	40, 80, 160,	106 + 26	MRU3 and MRU4,
			or 320		respectively
		86-89	80, 160, or	106 + 26	MRU5 to MRU8,
			320		respectively
		90-93	80, 160, or	484 + 242	MRU1 to MRU4,	4 × N +
			320		respectively	MRU index
0-1:	0	94, 95	160 or 320	996 + 484	MRU1 and MRU2,	4 × X1 +
160 MHz					respectively	MRU index
segment	1				MRU3 and MRU4,
where the					respectively
MRU is
located
0-1:	0	96-99	160 or 320	996 +	MRU1 to MRU4,	8 × X1 +
160 MHz				484 + 242	respectively	MRU index
segment	1				MRU5 to MRU8,
where the					respectively
MRU is
located
0	0	100-103	320	2 ×	MRU1 to MRU4,	MRU index
				996 + 484	respectively
0	1				MRU5 and MRU6,
					respectively
1	0				MRU7 and MRU8,
					respectively
1	1				MRU9 to MRU12,
					respectively
0	0	104	320	3 × 996	MRU1	MRU index
0	1				MRU2
1	0				MRU3
1	1				MRU4
0	0	105, 106	320	3 ×	MRU1 and MRU2,	MRU index
				996 + 484	respectively
0	1				MRU3 and MRU4,
					respectively
1	0				MRU5 and MRU6,
					respectively
1	1				MRU7 and MRU8,
					respectively
Any	Any	107-127	Any	Reserved	Reserved	Reserved

If 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 if the 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. If B0 in the RU allocation subfield is set to 0, the RU/MRU allocation may be applied to the lower 80 MHz of the secondary 160 MHz, and if B0 in the RU allocation subfield is set to 1, it may indicate that RU allocation is applied to the upper 80 MHz of the secondary 160 MHz.

In the trigger frame RU allocation table of Table 3, the parameter N may be calculated based on the formula N=2*X1+X0. For bandwidths below 80 MHz, the PS160, B0, X0, and X1 values can be set to 0. For 160 MHz bandwidth and 320 MHz bandwidth, PS160, B0, X0, and X1 values may be set as shown in Table 4. This configuration represents the absolute frequency order for the primary and secondary 80 MHz and 160 MHz channels. The order from left to right indicates the order of frequencies from low to high. The primary 80 MHz channel is displayed as P80, the secondary 80 MHz channel is displayed as S80, and the secondary 160 MHz channel is displayed as S160.

TABLE 3
Bandwidth	Inputs	Outputs
(MHz)	Configuration	PS160	B0	X0	X1	N
20/40/80	[P80]	0	0	0	0	0
160	[P80 S80]	0	0	0	0	0
		0	1	1	0	1
	[S80 P80]	0	0	1	0	1
		0	1	0	0	0
320	[P80 S80 S160]	0	0	0	0	0
		0	1	1	0	1
		1	0	0	1	2
		1	1	1	1	3
	[S80 P80 S160]	0	0	1	0	1
		0	1	0	0	0
		1	0	0	1	2
		1	1	1	1	3
	[S160 P80 S80]	0	0	0	1	2
		0	1	1	1	3
		1	0	0	0	0
		1	1	1	0	1
	[S160 S80 P80]	0	0	1	1	3
		0	1	0	1	2
		1	0	0	0	0
		1	1	I	0	1

Method for Indicating Puncturing Patterns at 480 MHz and 640 MHz Bandwidths

In wireless LAN systems, various puncturing patterns have been defined to improve efficiency and throughput.

In a wireless LAN system based on IEEE 802.11be, various preamble puncturing methods may be applied to MU PPDUs of 80 MHz or higher. The method of indicating the pattern of preamble puncturing can be defined differently depending on non-OFDMA or OFDMA transmission.

Specifically, the pattern of preamble puncturing may be indicated through the punctured channel information field of the U-SIG field of the MU PPDU, and the punctured channel information field may consist of 5 bits.

When a non-OFDMA transmission method is applied/configured, a puncturing pattern corresponding to the bandwidth of the entire MU PPDU may be indicated by a 5-bit punctured channel information field. That is, the punctured channel information fields in the U-SIG field of all 20 MHz channels except for the punctured 20 MHz channel may be set to the same value.

When OFDMA transmission method is applied/set, 80 MHz puncturing pattern may be indicated in bitmap manner through 4 bits of 5-bit punctured channel information field. That is, when the OFDMA transmission method is applied/set, the punctured channel information field value in the U-SIG field for each 80 MHz may be set to different values. And, the punctured channel information fields in the U-SIG field of all 20 MHz channels except for the punctured 20 MHz channel within a specific 80 MHz may be set to the same value.

And, the puncturing pattern of the 80 MHz channel to which the (punctured) 20 MHz channel belongs may be indicated based on the bitmap. Each bit constituting the bitmap may correspond to/map to each of the lowest 20 MHz and the highest 20 MHz of the 80 MHz channel.

If a specific bit value of the bitmap is 1 (or 0), it may be indicated that 20 MHZ corresponding to the specific bit is not punctured. And, if a specific bit value of the bitmap is 0 (or 1), it may be indicated that 20 MHz corresponding to the specific bit is punctured.

In the next-generation wireless LAN system, various preamble puncturing methods may be applied to MU PPDUs of 80 MHz or higher. For example, bandwidths such as 480 MHz and/or 640 MHz may be additionally defined, and a method for indicating a puncturing pattern in the corresponding bandwidth may be applied/defined.

FIG. 15 is a drawing for explaining an operation performed by a first STA according to one embodiment of the present disclosure.

In FIG. 15 and FIG. 16, the first STA may be a non-AP STA and the second STA may be an AP STA, but is not limited thereto. The first STA may be implemented as an AP STA and the second STA may be implemented as a non-AP STA.

A first STA may generate a Physical layer Protocol Data Unit (PPDU) including a first U (universal)-signal (SIG) field related to a first bandwidth and a second U-SIG field related to a second bandwidth (S1510).

Here, the first bandwidth may be one of the primary 160 MHz or the primary 320 MHZ, and the second bandwidth can be one of the secondary 320 MHz or a specific 160 MHz within the secondary 320 MHz.

However, this is only one embodiment, and each of the first bandwidth and the second bandwidth may be 80 MHz. For example, when the total bandwidth is 640 MHz, the total bandwidth may be divided into a first bandwidth, a second bandwidth, a third bandwidth, a fourth bandwidth, a fifth bandwidth, a sixth bandwidth, a seventh bandwidth, and an eighth bandwidth, and each bandwidth may be all 80 MHz. As another example, when the total bandwidth is 480 MHz, the total bandwidth may be divided into a first bandwidth to a sixth bandwidth, and each bandwidth may be all 80 MHz.

The first U-SIG field may include a first punctured channel information field indicating a first puncturing pattern among a plurality of puncturing patterns corresponding to the first bandwidth. For example, the plurality of puncturing patterns corresponding to the first bandwidth may include at least one puncturing pattern defined for the first bandwidth and at least one puncturing pattern defined for a bandwidth equal to or less than the first bandwidth.

The second U-SIG field may include a second punctured channel information field indicating first and second puncturing patterns among a plurality of puncturing patterns corresponding to the second bandwidth. As an example, the plurality of puncturing patterns corresponding to the second bandwidth may include at least one puncturing pattern defined for the second bandwidth and at least one puncturing pattern defined for a bandwidth equal to or less than the second bandwidth.

Here, the puncturing pattern defined for each of the first bandwidth and the second bandwidth may mean a 5-bit based puncturing pattern disclosed in Table 1.

Each of the first punctured channel information field and the second punctured channel information field may be set to different values, but may also be set to the same value.

Additionally or alternatively, the first U-SIG field may include first information indicating one of a first bandwidth and a bandwidth less than or equal to the first bandwidth, and the second U-SIG field may include second information indicating one of a second bandwidth and a bandwidth less than or equal to the second bandwidth.

Based on the specific bandwidth being indicated by the first information, the first punctured channel information field may indicate a first puncturing pattern among at least one puncturing pattern corresponding to the indicated specific bandwidth. That is, the first puncturing pattern among at least one puncturing pattern corresponding to the bandwidth indicated by the first information may be indicated by the first punctured channel information field.

And, based on the specific bandwidth being indicated by the second information, the second punctured channel information field may indicate a second puncturing pattern among at least one puncturing pattern corresponding to the indicated specific bandwidth. That is, the second puncturing pattern among at least one puncturing pattern corresponding to the bandwidth indicated by the second information may be indicated by the second punctured channel information field.

The first information may be indicated by a first field included in a first punctured channel information field or a first U-SIG field. The second information may be indicated by a second field included in a second punctured channel information field or a second U-SIG field.

Here, the first information and/or the second information may be composed of 3 bits or less. For example, if the first information and/or the second information indicates one of 320/160/80/40/20 MHZ, the first information and/or the second information may be composed of 3 bits. As another example, the first information and/or the second information may be composed of 3 bits or less and configured to indicate a limited bandwidth.

Additionally or alternatively, the first punctured channel information field may include a bitmap indicating a first puncturing pattern, and the second punctured channel information field may include a bitmap indicating a second puncturing pattern.

When the entire bandwidth is composed of the first bandwidth to the sixth bandwidth (or the eighth bandwidth), the punctured channel information field corresponding to each bandwidth may include a bitmap indicating a separate puncturing pattern.

The first STA may transmit a PPDU including a first U-SIG field and a second U-SIG field to the second STA (S1520).

For example, a first STA may transmit a PPDU including a first U-SIG field to a second STA in a remaining bandwidth excluding a first specific bandwidth punctured by a first punctured channel information field among a first bandwidth. And, the first STA may transmit a PPDU including a second U-SIG field to a second STA in a remaining bandwidth excluding a second specific bandwidth punctured by a second punctured channel information field among a second bandwidth.

Here, a plurality of U-SIG fields corresponding to each of a plurality of 20 MHz channels constituting the remaining bandwidth excluding the first specific bandwidth punctured by the first punctured channel information field among the first bandwidth may be identical to each other. And, a plurality of U-SIG fields corresponding to each of a plurality of 20 MHz channels constituting the remaining bandwidth excluding the second specific bandwidth punctured by the second punctured channel information field among the second bandwidth may be identical to each other.

And, the PPDU may include a non-OFDMA (orthogonal frequency division multiplexing access) based MU (multi-user) PPDU. However, this is only an embodiment, and the PPDU may include an OFDMA based MU PPDU.

For a basic wireless communication system, a puncturing pattern may be indicated/set through a punctured channel information field value in a U-SIG field corresponding to a single bandwidth.

According to the above-described method of the present disclosure, the punctured channel information field value of the U-SIG field corresponding to each bandwidth constituting the entire bandwidth may indicate/set a puncturing pattern of each bandwidth. That is, by dividing the entire bandwidth into a plurality of bandwidths, and indicating/setting one of the puncturing patterns defined for the plurality of bandwidths through the punctured channel information field of the U-SIG field within the plurality of divided bandwidths, a puncturing pattern for the entire bandwidth can be indicated/set.

Accordingly, even if a wider overall bandwidth is defined/set/indicated, ambiguity regarding preamble puncturing may be resolved and throughput may be improved as a puncturing pattern is indicated for each bandwidth constituting the overall bandwidth.

FIG. 16 is a drawing for explaining an operation performed by a second STA according to one embodiment of the present disclosure.

The second STA may transmit information related to the total bandwidth for PPDU transmission to the first STA (S1610).

For example, the second STA may transmit information related to the total bandwidth for PPDU transmission to the first STA via a trigger frame or another type of PPDU. For example, the information related to the total bandwidth for PPDU transmission may be indicated via a BW field included in the trigger frame or another type of PPDU.

The second STA may receive a PPDU including a first U-SIG field related to a first bandwidth and a second U-SIG field related to a second bandwidth from the first STA (S1620).

The entire bandwidth may be composed of a first bandwidth and a second bandwidth, but is not limited thereto. The entire bandwidth may be composed of bandwidths in units of 80 MHz. Here, the number of bandwidths in units of 80 MHz may be 6 or 8, but is not limited thereto.

The features related to the structure of the PPDU and U-SIG fields described with reference to FIG. 16 correspond to the features related to the structure of the PPDU and U-SIG fields described with reference to FIG. 15, so redundant description is omitted.

Hereinafter, a method for indicating a puncturing pattern in a 480 MHz and/or 640 MHz bandwidth is described.

A method for indicating a puncturing pattern in a next-generation wireless LAN system may be based on a punctured channel information field of a U-SIG field, as in a wireless LAN system based on IEEE 802.11be. Hereinafter, a method for indicating a puncturing pattern by distinguishing between a non-OFDMA transmission situation and an OFDMA transmission situation will be described.

Embodiment 1

Embodiment 1 relates to a method for indicating a puncturing pattern in a non-OFDMA transmission situation.

In case of non-OFDMA transmission in the 480 MHz and/or 640 MHz band, a puncturing pattern suitable for the bandwidth may be defined. For example, a puncturing pattern for 480 MHz and/or 640 MHz may be additionally defined in addition to a puncturing pattern in a predefined bandwidth of 80 MHz to 320 MHz.

The method the puncturing pattern for 480 MHz and/or 640 MHz is defined may be distinguished depending on whether there is a dependency on the puncturing pattern of the existing bandwidth.

Embodiment 1-1

A puncturing pattern at 480 MHz and/or 640 MHz may be defined without dependency on the puncturing pattern of the existing bandwidth (e.g., a puncturing pattern of 320 MHz or less). That is, when transmitting a 480 MHz and/or 640 MHz MU PPDU, the puncturing pattern of the corresponding bandwidth can be additionally defined regardless of the puncturing pattern of the existing bandwidth.

In a wireless LAN system based on IEEE 802.11be, a puncturing pattern at 480 MHz and/or 640 MHz may be indicated by considering the entire bandwidth by the puncturing channel information field in the U-SIG field, similarly to a non-OFDMA transmission situation of a specific bandwidth. That is, the punctured channel information fields in the U-SIG field of all 20 MHz channels except for the punctured 20 MHz channel may be set to the same value.

Here, the puncturing pattern indication method at 480 MHz may be considered as a special case of the puncturing pattern indication method at 640 MHz. Here, the puncturing pattern applicable to 480 MHz may be included in the puncturing pattern applicable to 640 MHz. In addition, 640 MHz may be indicated by the BW field (of the U-SIG field), but 480 MHz may not be indicated. That is, the BW field (of the U-SIG field) may have information/values indicating 640 MHz added to it, but information/values indicating 480 MHz may not be added.

As another example, the puncturing pattern indication method at 480 MHz may be defined independently from the puncturing pattern indication method at 640 MHz. In this case, not only 640 MHz but also 480 MHz may be indicated by the BW field (of the U-SIG field).

Additionally or alternatively, additional puncturing patterns may be defined for bandwidths below 320 MHz in addition to the existing puncturing patterns.

The number of bits in the punctured channel information field may include 5 bits or 6 bits, depending on the number of puncturing patterns added for bandwidths less than or equal to 320 MHz and/or puncturing patterns defined for 480/640 MHz.

When Embodiment 1-1 is applied, there is a technical effect that puncturing pattern information applied to the MU PPDU can be acquired even if only some channels in the MU PPDU are decoded.

Embodiment 1-2

Puncturing patterns at 480 MHz and/or 640 MHz may be defined with dependency on puncturing patterns of existing bandwidths (e.g., puncturing patterns below 320 MHz).

That is, a puncturing pattern at 480 MHz and/or 640 MHz may be defined based on a puncturing pattern for a bandwidth of 320 MHz or less. And, in addition to the predefined puncturing pattern for each bandwidth of 320 MHz or less, an additional puncturing pattern may be defined.

As described in Embodiment 1-1, when transmitting an MU PPDU of up to 320 MHZ, the punctured channel information field in the U-SIG field of all 20 MHz channels except for the punctured 20 MHz channel in the MU PPDU may be set to a value corresponding to the puncturing pattern applied to the MU PPDU.

When transmitting MU PPDU at 480 MHz and/or 640 MHZ, the puncturing channel information field may be set according to the method described in embodiment 1-1, but is not limited thereto. Hereinafter, a new method for indicating a puncturing pattern that may be applied when transmitting MU PPDU at 480 MHz and/or 640 MHz is described.

As an example of the present disclosure, it is assumed that the puncturing pattern indication method at 480 MHz is considered a special case of the puncturing pattern indication method at 640 MHz.

The puncturing pattern of 640 MHz may be configured by a combination of preamble puncturing patterns defined in each of the primary 320 MHz and the secondary 320 MHz. The preamble puncturing pattern defined in each of the primary 320 MHz (hereinafter, P320) and the secondary 320 MHz (hereinafter, S320) may be a preamble puncturing pattern defined in a bandwidth of 320 MHz or less.

Here, each of the punctured channel information fields of the U-SIG fields of P320 and S320 may be set to different values. That is, the contents of the U-SIG field in the P320 may be the same and the contents of the U-SIG field in the S320 may be the same, but the contents of the U-SIG field in the P320 and the contents of the U-SIG field in the S320 may be different.

The punctured channel information field of the U-SIG field of all 20 MHz channels except the punctured 20 MHz channels within P320 may indicate the puncturing pattern of P320.

The puncturing pattern of P320 may be one of the puncturing patterns defined for a 320 MHz bandwidth. In this case, when 160 MHz or more is punctured in P320, one of the puncturing patterns defined for a 160/80/40/20 MHz bandwidth may be indicated.

Additionally, the punctured channel information field of the U-SIG field of all 20 MHz channels except the punctured 20 MHz within the S320 may indicate the puncturing pattern of the S320.

The puncturing pattern of S320 may be one of the puncturing patterns defined for a 320 MHz bandwidth. In this case, when 160 MHz or more is punctured in S320, one of the puncturing patterns defined for a 160/80/40/20 MHz bandwidth may be indicated.

Additionally or alternatively, assume that 480 MHz (i.e., a puncturing pattern for 480 MHz) is additionally defined.

Here, the indication of the puncturing pattern for 640 MHz may be the same as when 480 MHz is considered as a special case of 640 MHZ, and preamble puncturing above 160 MHz may not be considered in P320 and S320.

The puncturing pattern at 480 MHz may be based on a combination of ‘P160 (i.e., primary 160 MHz)+S320’ or ‘a combination of a specific 160 MHz (hereinafter, SS160) in P320+S320’.

‘The combination of P160 (i.e., primary 160 MHz)+S320’ may mean a combination of a puncturing pattern applicable to P160 and a puncturing pattern applicable to S320. In this case, the punctured channel information fields in the U-SIG in P160 and S320 may be set to different values.

That is, the U-SIG content within the P160 is the same and the U-SIG content within the S320 is the same, but the U-SIG content within the P160 and the U-SIG content within the S320 may be different from each other.

The punctured channel information field of the U-SIG field of all 20 MHz channels except the punctured 20 MHz channels within P160 may indicate the puncturing pattern of P160.

A puncturing pattern applicable to P160 (i.e., a puncturing pattern of P160) may be one of the puncturing patterns defined in a 160 MHz bandwidth. However, when a bandwidth of 80 MHz or more is punctured in P160, a puncturing pattern applicable to P160 may be a puncturing pattern defined in a 80/40/20 MHz bandwidth.

Additionally, the punctured channel information field of the U-SIG field of all 20 MHz channels except the punctured 20 MHz channels within the S320 may indicate the punctured channel of the S320.

A puncturing pattern applicable to S320 (i.e., a puncturing pattern of S320) may be one of the puncturing patterns defined in a 320 MHz bandwidth. However, if 160 MHz or more is punctured within S320, the puncturing pattern applicable to S320 may be a puncturing pattern defined in a 160/80/40/20 MHz bandwidth.

‘Combination of P320+SS160’ may mean a combination of a puncturing pattern applicable to P320 and a puncturing pattern applicable to SS160. In this case, the punctured channel information fields in the U-SIG in P320 and SS160 may be set to different values.

That is, the U-SIG content within the P320 is the same and the U-SIG content within the SS160 is the same, but the U-SIG content within the P320 and the U-SIG content within the SS160 may be different from each other.

The punctured channel information field of the U-SIG field of all 20 MHz channels except the punctured 20 MHz channels within P320 may indicate the puncturing pattern of P320.

The puncturing pattern of the P320 may be one of the puncturing patterns defined in the 320 MHz bandwidth. However, if more than 160 MHz is punctured in the P320, the puncturing pattern of the P320 may be a puncturing pattern defined in the 160/80/40/20 MHz bandwidth.

Additionally, the punctured channel information field of the U-SIG field of all 20 MHz channels except the punctured 20 MHz channels within SS160 may indicate the puncturing pattern of SS160.

The puncturing pattern of SS160 may be one of the puncturing patterns defined in the 160 MHz bandwidth. However, if more than 80 MHz is punctured in SS160, the puncturing pattern of SS160 may be a puncturing pattern defined in the 80/40/20 MHz bandwidth.

The number of bits in the punctured channel information field may be 5 or 6 bits, depending on the number of puncturing patterns used in each bandwidth of 320 MHz or less.

Additionally or alternatively, when a bandwidth of 160/80 MHz or more is punctured in each 320/160 MHz channel constituting 480/640 MHZ, a puncturing pattern of 160/80/40/20 MHz rather than 320 MHz may be indicated, and a puncturing pattern of 80/40/20 MHz rather than 160 MHz may be indicated.

Accordingly, it may be additionally indicated what bandwidth of puncturing pattern value the punctured channel information field in each 320/160 MHz channel is composed of.

As an example of the present disclosure, assume that 480 MHz is a special case of 640 MHz. More than 160 MHz of bandwidth can be punctured in each 320 MHz (i.e., P320 and S320) that constitutes 640 MHz.

Here, the punctured channel information field may be configured to indicate a puncturing pattern corresponding to 160/80/40/20 MHZ, and 3 bits may be added to indicate 320/160/80/40/20 MHZ (i.e., a puncturing pattern corresponding to 320/160/80/40/20 MHz).

Additionally or alternatively, 320 MHz (i.e., a puncturing pattern corresponding to 320 MHz) or another bandwidth may be indicated by an additional 1 bit or 2 bits. As another example, 320 MHz or 160 MHz may be indicated by an additional 1 bit.

The additional 1/2/3 bits described above may be included in the punctured channel information field, but are not limited thereto. The additional 1/2/3 bits described above may be defined as a new field. And, the additional 1/2/3 bits described above may be reserved or used for other purposes in bandwidths other than 640 MHz.

As another example of the present disclosure, assume that a bandwidth of 480 MHz is additionally defined. In this case, no additional bits may be required since puncturing in bandwidths greater than 160 MHz is not considered for each of the 320 MHZ (i.e., P320 and S320) channels constituting 640 MHz.

Additionally or alternatively, if more than 80 or 160 MHz of bandwidth is punctured in each of the 160 MHz and 320 MHz channels constituting 480 MHZ, 3 bits may be added to indicate 320/160/80/40/20 MHZ (i.e., a puncturing pattern corresponding to 320/160/80/40/20 MHz).

As another example, puncturing may be applied to a bandwidth of 80 MHz or more in a 160 MHz channel. In this case, a punctured channel information field may be configured to indicate a puncturing pattern of 80/40/20 MHz, and 2 bits may be added to indicate 160/80/40/20 MHz (i.e., a puncturing pattern corresponding to 160/80/40/20 MHz).

As another example, 160 MHz (i.e., a puncturing pattern corresponding to 160 MHz) and other bandwidths can be indicated through an additional 1 or 2 bits. As another example, 160 MHz or 80 MHz (i.e., a puncturing pattern corresponding to 80 MHz) can be indicated through an additional 1 bit.

The additional 1/2/3 bits described above may be included in the punctured channel information field, but are not limited thereto. The additional 1/2/3 bits described above may be defined as a new field. And, the additional 1/2/3 bits described above may be reserved or used for other purposes in bandwidths other than 480 MHz.

And, the additional bits in the 160 MHz channel may be less than or equal to the number of additional bits used in the 320 MHz channel. If the number of additional bits in the 160 MHz channel is less than the number of additional bits used in the 320 MHz channel, only some of the additional bits used in the 320 MHz channel may be used for the 160 MHz channel, and the remaining bits may be reserved or used for other purposes.

As another example of the present disclosure, it is assumed that there is no additional bit as described above on the punctured information field or no separate new field composed of additional bits. In this case, a puncturing pattern defined in a 320 MHz bandwidth may always be indicated in a 320 MHz channel constituting 640/480 MHz. And, a puncturing pattern defined in a 160 MHz bandwidth may always be indicated in a 160 MHz channel constituting 640/480 MHz.

A puncturing pattern generated by puncturing of a bandwidth of 160/80 MHz or more may be additionally defined as a puncturing pattern of a bandwidth of 320/160 MHz. The added puncturing pattern may not be used as a puncturing pattern for MU PPDU transmission of 320/160 MHz, and may be used only in each 320/160 MHz channel for MU PPDU transmission of 640/480 MHz. Therefore, in the MU PPDU of 320/160 MHZ, values for indicating the additional puncturing pattern may be reserved or used for other purposes.

When the above-described embodiment 1-2 is applied, a puncturing pattern in units of 320/160 MHz can be used to configure a puncturing pattern corresponding to 640/480 MHz.

Embodiment 1-3

Embodiment 1-3 relates to a method of indicating a puncturing pattern through a bitmap, such as an OFDMA transmission method.

The punctured channel information field value of the U-SIG field for each 80 MHz channel may be set to different values. That is, U-SIG contents within a specific 80 MHz can be identical, but different U-SIG contents may be set for each 80 MHz.

In each 80 MHz channel, a puncturing pattern of 80 MHz to which the 20 MHz channel belongs may be indicated in a bitmap manner in all 20 MHz channels except for the punctured 20 MHz channel.

That is, the punctured channel information field may be composed of 4 bits, and each bit of the punctured channel information field may be mapped from the lowest 20 MHz to the highest 20 MHz. When a specific bit value of the punctured channel information field is set to 1 (or 0), this may indicate that 20 MHz corresponding to the specific bit is not punctured.

When a specific bit value of the punctured channel information field is set to 0 (or 1), this may indicate that 20 MHz corresponding to the specific bit is punctured.

Additionally or alternatively, the punctured channel information field of the U-SIG field for each 80 MHz channel may indicate a puncturing pattern defined for the 80 MHz channel rather than a bitmap. In this case, the punctured channel information field of the U-SIG field for each 80 MHz channel may be set to a different value. That is, the U-SIG contents within a specific 80 MHz may be the same, but different U-SIG contents may be set for each 80 MHz.

Additionally or alternatively, the puncturing pattern defined in the 80 MHz bandwidth/channel may be the same as, but configured differently from, the puncturing pattern defined for the MU PPDU of the 80 MHz bandwidth.

As another example, a puncturing pattern defined for an MU PPDU of 80 MHz bandwidth may be configured based on the puncturing pattern defined for 80 MHz bandwidth and other puncturing patterns.

A punctured channel information field in the U-SIG field of all 20 MHz channels except for the punctured 20 MHz channels within each 80 MHz channel may indicate a puncturing pattern of 80 MHz to which the 20 MHz channel belongs. A punctured channel information field of 4 bits or less may be configured according to the number of puncturing patterns defined in the 80 MHz channel.

Embodiment 1-3 may indicate a puncturing pattern applied to an MU PPDU regardless of the puncturing pattern defined in each bandwidth, so that flexibility related to the definition of the puncturing pattern can be improved.

Embodiment 2

Embodiment 2 relates to a method for indicating a puncturing pattern in an OFDMA transmission situation.

As an example of the present disclosure, a method for indicating a puncturing pattern in a non-OFDMA transmission situation may be applied/defined even in an OFDMA transmission situation.

Additionally or alternatively, the method according to embodiment 1-3 may be applied for resiliency in OFDMA transmission.

Specifically, if a punctured channel information field of 4 or more bits indicating a puncturing pattern in a bitmap manner is defined (or/and a 4-bit field is used for puncturing pattern indication in non-OFDMA transmission), bitmap-based puncturing pattern indication may be performed using only the first or last 4 bits of the punctured channel information field, and the last bit of the punctured channel information field may be reserved or used for other purposes.

As another example of the present disclosure, it is assumed that a punctured channel information field of x bits or more is defined to indicate a puncturing pattern in a non-OFDMA transmission situation. In this case, if a method of indicating a puncturing pattern of an 80 MHz channel using x bits (for example, x is a natural number less than or equal to 4) is applied, the puncturing pattern may be indicated by the first or last x bits of the punctured channel information field. In addition, the remaining bits except for the x bits of the punctured channel information field may be reserved or used for other purposes.

If the punctured channel information field is not defined identically in a non-OFDMA transmission situation and an OFDMA transmission situation, a non-OFDMA transmission or an OFDMA transmission may be distinguished by a specific field of the U-SIG field. That is, a non-OFDMA transmission or an OFDMA transmission may be indicated by a specific field of the U-SIG field.

FIG. 17 is a diagram for explaining a PPDU transmission and reception procedure between a transmitting STA and a receiving STA according to one embodiment of the present disclosure. Some step(s) shown in FIG. 17 may be omitted depending on the situation and/or setting. The transmitting device and the receiving STA may be an AP and/or a non-AP STA.

The transmitting STA may obtain control information related to the tone plan (or RU) described above (S105). The control information related to the tone plan can 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.

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 an EHT-SIG-A/B/C field including control information regarding a tone plan.

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.

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.

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

The transmitting STA may transmit the configured/generated PPDU to the receiving STA (S115).

Specifically, the transmitting STA may perform at least one of cyclic shift diversity (CSD), spatial mapping, inverse discrete Fourier transform (IDFT)/inverse fast Fourier transform (IFFT) operation, guard interval (GI) insert operation, etc.

The receiving STA may decode the PPDU and obtain control information related to the tone plan (or RU) (S120).

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

The receiving STA may decode the remaining part of the PPDU based on the information about the acquired tone-plan (i.e., RU) (S125). For example, the receiving STA may decode the STF/LTF field of the PPDU based on the information about the tone-plan (i.e., RU). In addition, the receiving STA may 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.

In addition, the receiving STA may perform a processing operation to transfer the decoded data to a higher layer (e.g., a MAC layer). In addition, if the generation of a signal is instructed from the higher layer to the PHY layer in response to the data transferred to the higher layer, the receiving STA may perform a subsequent operation.

Embodiments described above are that elements and features of the present disclosure are combined in a predetermined form. Each element or feature should be considered to be optional unless otherwise explicitly mentioned. Each element or feature may be implemented in a form that it is not combined with other element or feature. In addition, an embodiment of the present disclosure may include combining a part of elements and/or features. An order of operations described in embodiments of the present disclosure may be changed. Some elements or features of one embodiment may be included in other embodiment or may be substituted with a corresponding element or a feature of other embodiment. It is clear that an embodiment may include combining claims without an explicit dependency relationship in claims or may be included as a new claim by amendment after application.

It is clear to a person skilled in the pertinent art that the present disclosure may be implemented in other specific form in a scope not going beyond an essential feature of the present disclosure. Accordingly, the above-described detailed description should not be restrictively construed in every aspect and should be considered to be illustrative. A scope of the present disclosure should be determined by reasonable construction of an attached claim and all changes within an equivalent scope of the present disclosure are included in a scope of the present disclosure.

A scope of the present disclosure includes software or machine-executable commands (e.g., an operating system, an application, a firmware, a program, etc.) which execute an operation according to a method of various embodiments in a device or a computer and a non-transitory computer-readable medium that such a software or a command, etc. are stored and are executable in a device or a computer. A command which may be used to program a processing system performing a feature described in the present disclosure may be stored in a storage medium or a computer-readable storage medium and a feature described in the present disclosure may be implemented by using a computer program product including such a storage medium. A storage medium may include a high-speed random-access memory such as DRAM, SRAM, DDR RAM or other random-access solid state memory device, but it is not limited thereto, and it may include a nonvolatile memory such as one or more magnetic disk storage devices, optical disk storage devices, flash memory devices or other nonvolatile solid state storage devices. A memory optionally includes one or more storage devices positioned remotely from processor(s). A memory or alternatively, nonvolatile memory device(s) in a memory include a non-transitory computer-readable storage medium. A feature described in the present disclosure may be stored in any one of machine-readable mediums to control a hardware of a processing system and may be integrated into a software and/or a firmware which allows a processing system to interact with other mechanism utilizing a result from an embodiment of the present disclosure. Such a software or a firmware may include an application code, a device driver, an operating system and an execution environment/container, but it is not limited thereto.

A method proposed by the present disclosure is mainly described based on an example applied to an IEEE 802.11-based system, 5G system, but may be applied to various WLAN or wireless communication systems other than the IEEE 802.11-based system.

Claims

1. A method performed by a first station (STA) in a wireless LAN system, the method comprising: generating a Physical layer Protocol Data Unit (PPDU) including a first universal (U)-signal (SIG) field associated with a first bandwidth and a second U-SIG field associated with a second bandwidth; andtransmitting the PPDU including the first U-SIG field and the second U-SIG field to a second STA,wherein the first U-SIG field includes a first punctured channel information field indicating a first puncturing pattern among a plurality of puncturing patterns corresponding to the first bandwidth, andwherein the second U-SIG field includes a second punctured channel information field indicating a second puncturing pattern among a plurality of puncturing patterns corresponding to the second bandwidth.

2. The method of claim 1, wherein: the plurality of puncturing patterns corresponding to the first bandwidth include at least one puncturing pattern defined for the first bandwidth and at least one puncturing pattern defined for a bandwidth less than or equal to the first bandwidth, andthe plurality of puncturing patterns corresponding to the second bandwidth include at least one puncturing pattern defined for the second bandwidth and at least one puncturing pattern defined for a bandwidth less than or equal to the second bandwidth.

3. The method of claim 2, wherein: the first U-SIG field includes first information indicating one of the first bandwidth and a bandwidth less than or equal to the first bandwidth, andthe second U-SIG field includes second information indicating one of the second bandwidth and a bandwidth less than or equal to the second bandwidth.

4. The method of claim 3, wherein: the first puncturing pattern among at least one puncturing pattern corresponding to a bandwidth indicated by the first information is indicated by the first punctured channel information field, andthe second puncturing pattern among at least one puncturing pattern corresponding to a bandwidth indicated by the second information is indicated by the second punctured channel information field.

5. The method of claim 3, wherein: the first information is indicated by a first field included in the first punctured channel information field or the first U-SIG field, andthe second information is indicated by a second field included in the second punctured channel information field or the second U-SIG field.

6. The method of claim 1, wherein: the PPDU including the first U-SIG field is transmitted to the second STA in a remaining bandwidth excluding a first specific bandwidth punctured by the first punctured channel information field among the first bandwidth, andthe PPDU including the second U-SIG field is transmitted to the second STA in a remaining bandwidth excluding a second specific bandwidth punctured by the second punctured channel information field among the second bandwidth.

7. The method of claim 1, wherein: a plurality of U-SIG fields corresponding to each of a plurality of 20 MHz channels constituting a remaining bandwidth excluding a first specific bandwidth punctured by the first punctured channel information field among the first bandwidth are identical to each other, anda plurality of U-SIG fields corresponding to each of a plurality of 20 MHz channels constituting a remaining bandwidth excluding a second specific bandwidth punctured by the second punctured channel information field among the second bandwidth are identical to each other.

8. The method of claim 1, wherein: the first bandwidth is one of a primary 160 MHz or a primary 320 MHz, andthe second bandwidth is one of a secondary 320 MHz or a specific 160 MHz within a secondary 320 MHz.

9. The method of claim 1, wherein: each of the first punctured channel information field and the second punctured channel information field is set to different values.

10. The method of claim 1, wherein: the PPDU includes a orthogonal frequency division multiplexing access (non-OFDMA) based multi-user (MU) PPDU.

11. The method of claim 1, wherein: the first punctured channel information field includes a bitmap representing the first puncturing pattern, andthe second punctured channel information field includes a bitmap representing the second puncturing pattern.

12. The method of claim 11, wherein: the first bandwidth and the second bandwidth are each 80 MHz, andthe PPDU including at least one of a third U-SIG field corresponding to a third bandwidth, a fourth U-SIG field corresponding to a fourth bandwidth, a fifth U-SIG field corresponding to a fifth bandwidth, a sixth U-SIG field corresponding to a sixth bandwidth, a seventh U-SIG field corresponding to a seventh bandwidth, or an eighth U-SIG field corresponding to an eighth bandwidth is transmitted to the second STA.

13. The method of claim 12, wherein: each of the third bandwidth, the fourth bandwidth, the fifth bandwidth, the sixth bandwidth, the seventh bandwidth, and the eighth bandwidth is 80 MHz.

14. The method of claim 12, wherein: the PPDU includes an OFDMA-based MU PPDU.

15. The method of claim 11, wherein: the first STA is a non-access point (AP) STA, andthe second STA is an AP STA.

16. A first station (STA) in a wireless LAN system, the first STA comprising: at least one transceiver; andat least one processor connected to the at least one transceiver,wherein the at least one processor is configured to:generate a Physical layer Protocol Data Unit (PPDU) including a first U universal (U)-signal (SIG) field associated with a first bandwidth and a second U-SIG field associated with a second bandwidth; andtransmit the PPDU including the first U-SIG field and the second U-SIG field to a second STA through the at least one transceiver,wherein the first U-SIG field includes a first punctured channel information field indicating a first puncturing pattern among a plurality of puncturing patterns corresponding to the first bandwidth, andwherein the second U-SIG field includes a second punctured channel information field indicating a second puncturing pattern among a plurality of puncturing patterns corresponding to the second bandwidth.

17. (canceled)

18. A second station (STA) in a wireless LAN system, the second STA comprising:at least one transceiver; andat least one processor connected to the at least one transceiver,wherein the at least one processor is configured to:transmit, to the first STA through the at least one transceiver, information related to a total bandwidth for physical layer protocol data unit (PPDU) transmission; andreceive, from the first STA through the at least one transceiver, the PPDU including a first universal (U)-signal (SIG) field related to a first bandwidth among the total bandwidth and a second U-SIG field related to a second bandwidth among the total bandwidth,wherein the first U-SIG field includes a first punctured channel information field indicating a first puncturing pattern among a plurality of puncturing patterns corresponding to the first bandwidth, andwherein the second U-SIG field includes a second punctured channel information field indicating a second puncturing pattern among a plurality of puncturing patterns corresponding to the second bandwidth.

19-20. (canceled)