Method and apparatus for transmitting or receiving PPDU over a wide bandwidth in a wireless LAN system

Abstract

A method and apparatus for transmitting or receiving a physical layer protocol data unit (PPDU) for a wide bandwidth in a wireless LAN system are disclosed. A method performed by a first STA in a wireless LAN system according to an embodiment of the present disclosure may include generating a physical layer protocol data unit (PPDU) of a first type or a second type based on a multiple access type in a first frequency unit and a second frequency unit, respectively, and transmitting the PPDU to one or more second STAs on a bandwidth including the first frequency unit and the second frequency unit.

Description

Technical Field

[0001] The present disclosure relates to a method and apparatus for transmitting or receiving a PPDU (physical layer protocol data unit) for a wide bandwidth in a wireless LAN (Wireless Local Area Network, WLAN) system.

Background Art

[0002] New technologies have been introduced for improving the transmission rate, increasing the bandwidth, improving the reliability, reducing the error, and reducing the latency of wireless LAN (WLAN). Among the wireless LAN technologies, the IEEE (Institute of Electrical and Electronics Engineers) 802.11 series of standards can be referred to as Wi-Fi. For example, the technologies recently introduced into the wireless LAN include enhancements for VHT (Very High-Throughput) of the 802.11ac standard, enhancements for HE (High Efficiency) of the IEEE 802.11ax standard, and the like.

[0003] In order to provide a more improved wireless communication environment, improvement technologies for EHT (Extremely High Throughput) are being discussed. For example, technologies for an increased bandwidth, efficient utilization of multiple bands, MIMO (Multiple Input Multiple Output) that supports an increased spatial stream, and technologies for multi-access point (AP) adjustment are being studied. In particular, various technologies for supporting traffic with low latency or real-time characteristics are being studied. In addition, new technologies for supporting ultra-high reliability (UHR), including improvement or extension of EHT technology, are being discussed.

Summary of the Invention

Problems to be Solved by the Invention

[0004] The technical problem addressed by this disclosure is to provide a method and apparatus for transmitting or receiving PPDU over a wide bandwidth in a wireless LAN system.

[0005] A further technical challenge of this disclosure is to provide a method and apparatus for transmitting or receiving a PPDU including a non-legacy preamble configured based on a multiple access type in a portion of a broad bandwidth in a wireless LAN system.

[0006] A further technical challenge of this disclosure is to provide a method and apparatus for transmitting or receiving OFDMA (orthogonal frequency division multiple access) type PPDU or non-OFDMA type PPDU over a wide bandwidth in a wireless LAN system.

[0007] The technical challenges addressed in this disclosure are not limited to those mentioned above, and other technical challenges not mentioned will be clearly understood by those with ordinary skill in the art to which this disclosure pertains from the following description. [Means for solving the problem]

[0008] A method performed by a first STA in a wireless LAN system according to one aspect of the present disclosure may include the steps of: generating a first or second type PPDU (physical layer protocol data unit) based on the multiple access type in a first frequency unit and a second frequency unit, respectively; and transmitting the PPDU to one or more second STAs over the bandwidth including the first frequency unit and the second frequency unit.

[0009] A method performed by a second station (STA) in a wireless LAN system according to a further aspect of the present disclosure includes the steps of receiving a PPDU (physical layer protocol data unit) from the first STA in one or more of the first or second frequency units in a bandwidth including the first and second frequency units, and processing the received PPDU, wherein the PPDU may have a first-type or second-type format based on the respective multiple access types of the first and second frequency units. [Effects of the Invention]

[0010] This disclosure provides a method and apparatus for transmitting or receiving PPDU over a wide bandwidth in a wireless LAN system.

[0011] According to this disclosure, a method and apparatus for transmitting or receiving a PPDU including a non-legacy preamble set based on a multiple access type in a portion of a wide bandwidth in a wireless LAN system can be provided.

[0012] According to this disclosure, a method and apparatus for transmitting or receiving OFDMA (orthogonal frequency division multiple access) type PPDU or non-OFDMA type PPDU over a wide bandwidth in a wireless LAN system can be provided.

[0013] The effects derived from this disclosure are not limited to those mentioned above, and any other effects not mentioned above will be clearly understood by a person with ordinary skill in the art to which this disclosure pertains from the following description. [Brief explanation of the drawing]

[0014] The accompanying drawings, included as part of the detailed description to aid in understanding this disclosure, provide examples of the disclosure and illustrate the technical features of the disclosure together with the detailed description.

[0015] [Figure 1] This is a block diagram illustrating an example of a wireless communication device according to one embodiment of the present disclosure. [Figure 2] This figure shows an exemplary structure of a wireless LAN system to which this disclosure can be applied. [Figure 3] This diagram illustrates the link setup process to which this disclosure applies. [Figure 4] This diagram illustrates the backoff process to which this disclosure applies. [Figure 5] This diagram illustrates the CSMA / CA baseframe transmission operation to which this disclosure can be applied. [Figure 6] This figure illustrates an example of a frame structure used in a wireless LAN system to which this disclosure can be applied. [Figure 7] This figure shows an example of a PPDU as defined in the IEEE 802.11 standard to which this disclosure applies. [Figure 8] This figure illustrates an example of a resource unit in a wireless LAN system to which this disclosure can be applied. [Figure 9] This figure illustrates an example of a resource unit in a wireless LAN system to which this disclosure can be applied. [Figure 10] This figure illustrates an example of a resource unit in a wireless LAN system to which this disclosure can be applied. [Figure 11] This figure shows an exemplary structure of the HE-SIG-B field. [Figure 12] This diagram illustrates the MU-MIMO scheme, where multiple users / STAs are assigned to a single RU. [Figure 13] This figure shows examples of PPDU formats to which this disclosure can be applied. [Figure 14]This is a diagram for explaining an example of a PPDU transmission method for a wide bandwidth according to the present disclosure. [Figure 15] This is a diagram for explaining an example of a PPDU reception method for a wide bandwidth according to the present disclosure. [Figure 16] This is a diagram showing an exemplification of a PPDU format for a wide bandwidth according to the present disclosure. [Figure 17] This is a diagram showing an exemplification of a PPDU format for a wide bandwidth according to the present disclosure. [Figure 18] This is a diagram showing an exemplification of a PPDU format for a wide bandwidth according to the present disclosure. [Figure 19] This is a diagram showing a further exemplification of a PPDU format for a wide bandwidth according to the present disclosure. [Figure 20] This is a diagram showing a further exemplification of a PPDU format for a wide bandwidth according to the present disclosure. [Figure 21] This is a diagram showing a further exemplification of a PPDU format for a wide bandwidth according to the present disclosure.

Embodiments for Carrying Out the Invention

[0016] Hereinafter, preferred embodiments according to the present disclosure will be described in detail with reference to the accompanying drawings. The detailed description disclosed below together with the accompanying drawings is for explaining exemplary embodiments of the present disclosure, and is not for showing the only embodiments in which the present disclosure can be implemented. The following detailed description includes specific details for providing a complete understanding of the present disclosure. However, it is understood by those skilled in the art that the present disclosure can be implemented without such specific details.

[0017] In some cases, in order to avoid obscuring the concept of the present disclosure, known structures and devices may be omitted, or may be shown in the form of a block diagram centered on the core functions of each structure and device.

[0018] In this disclosure, when one component is “connected,” “joined,” or “linked” to another component, this may include not only a direct connection but also an indirect connection in which other components exist between them. Also, in this disclosure, the terms “includes” or “have” identify the presence of the referred features, stages, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, stages, operations, elements, components and / or groups thereof.

[0019] In this disclosure, terms such as "first," "second," etc., are used solely to distinguish one component from another, and are not used to limit the components, nor do they limit the order or importance of the components unless specifically mentioned. Therefore, within the scope of this disclosure, a first component in one embodiment may be referred to as a second component in another embodiment, and similarly, a second component in one embodiment may be referred to as a first component in another embodiment.

[0020] The terms used in this disclosure are for illustrative purposes relating to specific embodiments and are not intended to limit the scope of the claims. As used in the description of the embodiments and in the attached claims, singular forms are intended to include plural forms unless otherwise specified in the context. The terms "and / or" used in this disclosure may refer to one of the related enumerated items, or to any and all possible combinations of two or more of them. In this disclosure, a " / " between words has the same meaning as "and / or" unless otherwise specified.

[0021] The examples in this disclosure may be applied to a variety of wireless communication systems. For example, the examples in this disclosure may be applied to wireless LAN systems. For example, the examples in this disclosure may be applied to IEEE 802.11a / g / n / ac / ax standard-based wireless LANs. Furthermore, the examples in this disclosure may be applied to newly proposed IEEE 802.11be (or EHT) standard-based wireless LANs. The examples in this disclosure may be applied to IEEE 802.11be release-2 standard-based wireless LANs, which represent further improvements to the IEEE 802.11be release-1 standard. In addition, the examples in this disclosure may be applied to next-generation standard-based wireless LANs following IEEE 802.11be. Moreover, the examples in this disclosure may be applied to cellular wireless communication systems. For example, they may be applied to cellular wireless communication systems based on 3GPP® (3rd Generation Partnership Project) standard LTE (Long Term Evolution) series technologies and 5G NR (New Radio) series technologies.

[0022] The following describes the technical features to which the examples in this disclosure may apply.

[0023] Figure 1 is a block diagram illustrating an example of a wireless communication device according to one embodiment of the present disclosure.

[0024] The first device 100 and the second device 200 illustrated in Figure 1 may be replaced with various terms such as terminal, wireless device, WTRU (Wireless Transmit Receive Unit), UE (User Equipment), MS (Mobile Station), UT (user terminal), MSS (Mobile Subscriber Station), MSS (Mobile Subscriber Unit), SS (Subscriber Station), AMS (Advanced Mobile Station), WT (Wireless terminal), or simply user. Furthermore, the first device 100 and the second device 200 may be replaced with various terms such as access point (AP), BS (Base Station), fixed station, Node B, BTS (base transceiver system), network, AI (Artificial Intelligence) system, RSU (roadside unit), repeater, router, relay, gateway, etc.

[0025] The devices 100 and 200 illustrated in Figure 1 can also be referred to as stations (STA). For example, the devices 100 and 200 illustrated in Figure 1 can be referred to by various terms such as transmitting device, receiving device, transmitting STA, and receiving STA. For example, STA 110 and 200 can play the role of an AP (access point) or a non-AP. That is, in this disclosure, STA 110 and 200 may have AP and / or non-AP functions. When STA 110 and 200 have AP functions, they can simply be called APs, and when STA 110 and 200 have non-AP functions, they can simply be called STAs. In addition, in this disclosure, AP may be represented as AP STA.

[0026] Referring to Figure 1, the first device 100 and the second device 200 can send and receive wireless signals using various wireless LAN technologies (e.g., the IEEE 802.11 series). The first device 100 and the second device 200 may include interfaces to the medium access control (MAC) layer and the physical layer (PHY) in accordance with the IEEE 802.11 standard.

[0027] Furthermore, the first device 100 and the second device 200 can also further support various communication standards other than Wi-Fi technology (e.g., 3GPP LTE series, 5G NR series standards, etc.). The devices of this disclosure may also be embodied in various devices such as mobile phones, vehicles, personal computers, Augmented Reality (AR) equipment, and Virtual Reality (VR) equipment. In addition, the STA of this specification can support various communication services such as voice calls, video calls, data communication, autonomous driving, Machine-Type Communication (MTC), Machine-to-Machine (M2M), Device-to-Device (D2D), and Internet of Things (IoT).

[0028] The first device 100 includes one or more processors 102 and one or more memories 104, and may further include one or more transceivers 106 and / or one or more antennas 108. The processor 102 may control the memories 104 and / or the transceivers 106 and be configured to embody the descriptions, functions, procedures, suggestions, methods and / or operation diagrams of this disclosure. For example, the processor 102 may process information in the memory 104 to generate first information / signals and then transmit a radio signal containing the first information / signals via the transceiver 106. Alternatively, the processor 102 may receive a radio signal containing second information / signals via the transceiver 106 and then store information obtained from signal processing of the second information / signals in the memory 104. The memory 104 may be linked to the processor 102 and can store various information relating to the operation of the processor 102. For example, memory 104 may store software code that executes some or all of a process controlled by processor 102, or that contains instructions for executing the descriptions, functions, procedures, suggestions, methods and / or operation sequence diagrams in this disclosure. Here, processor 102 and memory 104 may be part of a communication modem / circuit / chip designed to embody wireless LAN technology (e.g., IEEE 802.11 series). Transceiver 106 may be coupled with processor 102 and can transmit and / or receive radio signals via one or more antennas 108. Transceiver 106 may include a transmitter and / or receiver. Transceiver 106 may be used synonymously with RF (Radio Frequency) unit. In this disclosure, device may also mean communication modem / circuit / chip.

[0029] The second device 200 includes one or more processors 202, one or more memories 204, and may further include one or more transceivers 206 and / or one or more antennas 208. The processor 202 may control the memories 204 and / or the transceivers 206 and be configured to embody the descriptions, functions, procedures, suggestions, methods and / or operation sequence diagrams disclosed herein. For example, the processor 202 may process information in the memory 204 to generate third information / signals and then transmit a radio signal containing the third information / signals via the transceiver 206. Alternatively, the processor 202 may receive a radio signal containing fourth information / signals via the transceiver 206 and then store information obtained from signal processing of the fourth information / signals in the memory 204. The memory 204 may be linked to the processor 202 and can store various information related to the operation of the processor 202. For example, memory 204 may store software code that executes some or all of the processes controlled by processor 202, or that contains instructions for executing the descriptions, functions, procedures, suggestions, methods and / or operation sequence diagrams disclosed in this disclosure. Here, processor 202 and memory 204 may be part of a communication modem / circuit / chip designed to embody wireless LAN technology (e.g., IEEE 802.11 series). Transceiver 206 may be coupled with processor 202 and may transmit and / or receive radio signals via one or more antennas 208. Transceiver 206 may include a transmitter and / or receiver. Transceiver 206 may be used synonymously with RF unit. In this disclosure, device may also mean communication modem / circuit / chip.

[0030] The hardware elements of devices 100,200 will be described in more detail below. However, one or more protocol layers may be embodied by one or more processors 102,202. For example, one or more processors 102,202 can embodied one or more layers (e.g., layers with the same functionality, such as PHY and MAC). One or more processors 102,202 can generate one or more PDUs (Protocol Data Units) and / or one or more SDUs (Service Data Units) by means of the descriptions, functions, procedures, proposals, methods and / or operation sequence diagrams in this disclosure. One or more processors 102,202 can generate messages, control information, data, or information by means of the descriptions, functions, procedures, proposals, methods and / or operation sequence diagrams in this disclosure. One or more processors 102,202 can generate signals (e.g., baseband signals) containing PDUs, SDUs, messages, control information, data, or information by the functions, procedures, proposals and / or methods of this disclosure and provide them to one or more transceivers 106,206. One or more processors 102,202 can receive signals (e.g., baseband signals) from one or more transceivers 106,206 and obtain PDUs, SDUs, messages, control information, data, or information by the descriptions, functions, procedures, proposals, methods and / or operation sequence diagrams of this disclosure.

[0031] One or more processors 102,202 may be referred to as controllers, microcontrollers, microprocessors, or microcomputers. One or more processors 102,202 may be embodied by hardware, firmware, software, or a combination thereof. For example, one or more ASICs (Application Specific Integrated Circuits), one or more DSPs (Digital Signal Processors), one or more DSPDs (Digital Signal Processing Devices), one or more PLDs (Programmable Logic Devices), or one or more FPGAs (Field Programmable Gate Arrays) may be included in one or more processors 102,202. The descriptions, functions, procedures, proposals, methods and / or operation sequence diagrams disclosed in this disclosure may be embodied using firmware or software, and the firmware or software may be embodied to include modules, procedures, functions, etc. Firmware or software configured to perform the descriptions, functions, procedures, suggestions, methods and / or sequence diagrams disclosed in this disclosure may be contained in one or more processors 102,202 or stored in one or more memories 104,204 and driven by one or more processors 102,202. The descriptions, functions, procedures, suggestions, methods and / or sequence diagrams disclosed in this disclosure may be embodied by firmware or software in the form of code, instructions and / or sets of instructions.

[0032] One or more memories 104,204 may be connected to one or more processors 102,202 and can store various forms of data, signals, messages, information, programs, code, instructions and / or commands. One or more memories 104,204 may consist of ROM, RAM, EPROM, flash memory, hard drives, registers, cache memory, computer-readable storage media and / or combinations thereof. One or more memories 104,204 may be located inside and / or outside of one or more processors 102,202. Furthermore, one or more memories 104,204 may be connected to one or more processors 102,202 by various technologies such as wired or wireless connections.

[0033] One or more transceivers 106,206 can transmit user data, control information, radio signals / channels, etc., as referred to in the methods and / or operation sequence diagrams of this disclosure, to one or more other devices. One or more transceivers 106,206 can receive user data, control information, radio signals / channels, etc., as referred to in the descriptions, functions, procedures, proposals, methods and / or operation sequence diagrams disclosed in this disclosure, from one or more other devices. For example, one or more transceivers 106,206 may be coupled with one or more processors 102,202 to transmit and receive radio signals. For example, one or more processors 102,202 can control one or more transceivers 106,206 to transmit user data, control information, or radio signals to one or more other devices. Also, one or more processors 102,202 can control one or more transceivers 106,206 to receive user data, control information, or radio signals from one or more other devices. Furthermore, 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, radio signals / channels, etc., as referred to in the descriptions, functions, procedures, proposals, methods and / or operation sequence diagrams disclosed in this disclosure, via one or more antennas 108,208. In this disclosure, one or more antennas may be multiple physical antennas or multiple logical antennas (e.g., antenna ports). One or more transceivers 106,206 may convert the received user data, control information, radio signals / channels, etc., from RF band signals to baseband signals for processing using one or more processors 102,202. One or more transceivers 106,206 may convert the user data, control information, radio signals / channels, etc., processed by one or more processors 102,202, from baseband signals to RF band signals. To this end, one or more transceivers 106,206 may include (analog) oscillators and / or filters.

[0034] For example, either STA100 or STA200 can perform the intended operation of an AP, and the other STA100 or STA200 can perform the intended operation of a non-AP STA. For example, the transceivers 106 and 206 in Figure 1 can perform the transmission and reception of signals (e.g., packets or PPDUs (Physical Layer Protocol Data Units) conforming to IEEE 802.11a / b / g / n / ac / ax / be, etc.). Furthermore, in this disclosure, the operation of various STAs generating transmission and reception signals or performing data processing and calculations in advance for transmission and reception signals may be performed by the processors 102 and 202 in Figure 1. For example, an example of an operation that generates transmit / receive signals or performs data processing or calculations in advance for transmit / receive signals may include: 1) an operation to determine / acquire / construct / calculate / decode / encode bit information of fields contained within the PPDU (SIG (signal), STF (short training field), LTF (long training field), Data, etc.); 2) an operation to determine / construct / acquire time resources and frequency resources (e.g., subcarrier resources) used for fields contained within the PPDU (SIG, STF, LTF, Data, etc.); 3) an operation to determine / construct / acquire specific sequences (e.g., pilot sequence, STF / LTF sequence, extra sequence applied to SIG) used for fields contained within the PPDU (SIG, STF, LTF, Data, etc.); 4) power control operations and / or power saving operations applied to the STA; and 5) operations related to determining / acquiring / constructing / calculating / decoding / encoding the ACK signal. Furthermore, in the following example, various pieces of information used by various STAs for determining / acquiring / composing / calculating / decoding / encoding the transmit / receive signals (e.g., information about fields / subfields / control fields / parameters / power, etc.) may be stored in memories 104,204 of Figure 1.

[0035] In the following, downlink (DL) refers to the link for communication from AP STA to non-AP STA, and downlink PPDU / packets / signals, etc., may be transmitted and received through the downlink. In downlink communication, the transmitter may be part of AP STA, and the receiver may be part of non-AP STA. Uplink (UL) refers to the link for communication from non-AP STA to AP STA, and uplink PPDU / packets / signals, etc., may be transmitted and received through the uplink. In uplink communication, the transmitter may be part of non-AP STA, and the receiver may be part of AP STA.

[0036] Figure 2 shows an exemplary structure of a wireless LAN system to which this disclosure can be applied.

[0037] The structure of a wireless LAN system may consist of multiple components. A wireless LAN may be provided that supports transparent STA mobility to higher layers through the interaction of multiple components. A BSS (Basic Service Set) corresponds to the basic structural block of a wireless LAN. Figure 2 illustrates the existence of two BSSs (BSS1 and BSS2), with each BSS containing two STAs as members (STA1 and STA2 are included in BSS1, and STA3 and STA4 are included in BSS2). In Figure 2, the ellipses representing the BSSs may be understood as representing the coverage area where the STAs included in that BSS maintain communication. This area can be called a BSA (Basic Service Area). When an STA moves outside a BSA, it can no longer communicate directly with other STAs within that BSA.

[0038] Ignoring the DS shown in Figure 2, the most basic type of BSS in a wireless LAN is the Independent BSS (IBSS). For example, an IBSS can have a minimal form consisting of only two STAs. For instance, assuming other components are omitted, BSS1 consisting only of STA1 and STA2, or BSS2 consisting only of STA3 and STA4, can each be considered a typical example of an IBSS. Such a configuration is possible when STAs can communicate directly without APs. Furthermore, this type of wireless LAN is not pre-planned and configured, but can be configured when the LAN requires it, and can be called an ad-hoc network. Since an IBSS does not include APs, there is no centralized management entity. That is, in an IBSS, STAs are managed in a distributed manner. In an IBSS, all STAs may be mobile STAs, and connection to a distributed system (DS) is not permitted, forming a self-contained network.

[0039] STA membership in the BSS can change dynamically due to actions such as STAs being added or removed, or STAs entering or leaving the BSS area. To become a member of the BSS, an STA can join the BSS using a synchronization process. To access all services of the BSS-based structure, an STA must be associated with the BSS. Such associations may be configured dynamically and may include the use of Distribution System Services (DSS).

[0040] In a wireless LAN, the direct distance between STAs may be limited by the PHY performance. While this distance limit may be sufficient in some cases, there may be situations requiring communication between STAs over longer distances. Distributed systems (DS) may be configured to support extended coverage.

[0041] DS refers to a structure in which BSSs are interconnected. Specifically, as shown in Figure 2, BSSs may exist as components of an extended form of a network composed of multiple BSSs. DS is a logical concept and may be identified by the characteristics of the Distributed System Medium (DSM). In this regard, Wireless Medium (WM) and DSM may be logically distinct. Each logical medium is used for a different purpose and by different components. These mediums are neither limited to being the same nor limited to being different. The flexibility of wireless LAN structures (DS structures or other network structures) can be explained by the fact that multiple mediums are logically distinct from one another. That is, wireless LAN structures can be embodied in various ways, and each embodied example may be identified independently by its physical characteristics.

[0042] DS can support mobile devices by providing seamless integration of multiple BSSs and offering the necessary logical services for handling destination addresses. DS may also include a portal component that acts as a bridge for connecting wireless LANs with other networks (e.g., IEEE 802.X).

[0043] An AP (Application Programming Object) is an entity that enables a coupled non-AP STA (Systematization System) to access the DS (Data Storage System) via the WM (Web Module) and also possesses the functionality of an STA. Data can be moved between the BSS (Base System Storage) and the DS via the AP. For example, STA2 and STA3, shown in Figure 2, possess the functionality of an STA while also providing the ability for coupled non-AP STAs (STA1 and STA4) to access the DS. Furthermore, since all APs are essentially 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 (Data Storage System) do not necessarily have to be the same. A BSS consisting of an AP and one or more STAs can be called an infrastructure BSS.

[0044] Data transmitted from one of the STAs connected to an AP to the AP's STA address is always received on an uncontrolled port and may be processed by an IEEE 802.1X port access entity. Alternatively, once a controlled port is authenticated, the transmitted data (or frame) may be forwarded to a DS.

[0045] An Extended Service Set (ESS) may be added to the aforementioned DS structure to provide even broader coverage.

[0046] An ESS (Service Set Network) refers to a network of arbitrary size and complexity composed of DSs (Distributed Service Sets) and BSSs (Blockchain Service Sets). An ESS can be a collection of BSSs connected to a single DS. However, an ESS cannot contain a DS. A key feature of an ESS network is that it appears as an IBSS (Internet Link Control Service Set) at the LLC (Logical Link Control) layer. STAs (Stage Attacks) within an ESS can communicate with each other, and mobile STAs can move transparently to the LLC from one BSS to another (within the same ESS). APs (Access Points) within an ESS may have the same SSID (Service Set Identification). An SSID is distinct from a BSSID, which is the identifier for a BSS.

[0047] In wireless LAN systems, no assumptions are made regarding the relative physical location of BSSs, and any of the following forms are possible: BSSs may partially overlap, which is a commonly used form to provide continuous coverage. BSSs do not have to be physically connected, and logically there is no limit to the distance between BSSs. BSSs may also be located in the same physical location, which may be used to provide redundancy. One (or more) IBSS or ESS networks may physically exist in the same space as one (or more) ESS networks. This may include ESS network configurations when an ad hoc network operates in the 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 at the same location.

[0048] Figure 3 is a diagram illustrating the link setup process to which this disclosure can be applied.

[0049] For an STA to set up a link to a network and send and receive data, it must first discover the network, perform authentication, establish an association, and carry out security authentication procedures. The link setup process can be called the session initiation process or session setup process. Alternatively, the discovery, authentication, association, and security setting processes of the link setup process can be collectively referred to as the association process.

[0050] In step S310, the STA can perform a network discovery operation. The network discovery operation may include the STA's scanning operation. That is, in order for the STA to access a network, it must find a network that it can join. Before joining a wireless network, the STA must identify a compatible network, and the process of identifying networks in a specific area is called scanning.

[0051] There are two scanning methods: active scanning and passive scanning. Figure 3 illustrates a network discovery operation that includes the active scanning process. In active scanning, the STA performing the scanning sends a probe request frame to search for nearby APs while moving between channels, and waits for a response. The responder sends a probe response frame to the STA that sent the probe request frame. Here, the responder may be the STA that last sent a beacon frame in the BSS of the channel being scanned. In BSS, APs send beacon frames, so APs become the responders, while in IBSS, STAs within IBSS alternately send beacon frames, so the responders are not constant. For example, an STA that sends a probe request frame on channel 1 and receives a probe response frame on channel 1 can save the BSS-related information contained in the received probe response frame and move to the next channel (e.g., channel 2) to perform scanning in the same way (i.e., send and receive probe requests / responses on channel 2).

[0052] Although not shown in Figure 3, scanning may also be performed using a passive scanning method. In passive scanning, the STA performing the scanning waits for beacon frames while switching channels. A beacon frame is one of the management frames defined in IEEE 802.11, and is transmitted periodically to announce the presence of a wireless network, allowing the scanning STA to find and join the wireless network. In BSS, APs are responsible for periodically transmitting beacon frames, while in IBSS, STAs within IBSS transmit beacon frames alternately. When the scanning STA receives a beacon frame, it stores the BSS information contained in the beacon frame and records the beacon frame information on each channel while moving to other channels. The STA that receives a beacon frame can store the BSS-related information contained in the received beacon frame and move to the next channel to perform scanning on the next channel in the same way. Comparing active scanning and passive scanning, active scanning has the advantage of less delay and power consumption compared to passive scanning.

[0053] After the STA discovers the network, an authentication process may be performed in step S320. This authentication process can be called the first authentication process to clearly distinguish it from the security setup operation in step S340, which will be described later.

[0054] The authentication process involves the STA sending an authentication request frame to the AP, and the AP responding by sending an authentication response frame to the STA. The authentication frame used in the authentication request / response corresponds to the management frame.

[0055] The authentication frame may include information such as the authentication algorithm number, authentication transaction sequence number, status code, challenge text, Robust Security Network (RSN), and Finite Cyclic Group. This is just an example of some of the information that may be included in the authentication request / response frame, and may be replaced by other information or may contain additional information.

[0056] The STA can send an authentication request frame to the AP. Based on the information contained in the received authentication request frame, the AP can decide whether or not to allow authentication to the STA. The AP can provide the STA with the result of the authentication process using an authentication response frame.

[0057] After the STA has been successfully authenticated, the association process may take place in step S330. The association process includes the STA sending an association request frame to the AP, and the AP sending an association response frame to the STA in response.

[0058] For example, an association request frame may include information about various capacities, such as the beacon listening interval, SSID (service set identifier), supported rates, supported channels, RSN, mobility domain, supported operating classes, TIM broadcast request (Traffic Indication Map Broadcast request), and interworking service capacity. For example, an association response frame may include information about various capacities, such as the status code, AID (Association ID), supported rates, EDCA (Enhanced Distributed Channel Access) parameter set, RCPI (Received Channel Power Indicator), RSNI (Received Signal to Noise Indicator), mobility domain, timeout interval (e.g., association comeback time), overlapping BSS scan parameters, TIM broadcast response, and QoS (Quality of Service) map. This is an example of some of the information that may be included in a join request / response frame, and may be replaced by other information or may include additional information.

[0059] After the STA is successfully connected to the network, the security setup process may be performed in step S340. The security setup process in step S340 can also be described as an authentication process using RSNA (Robust Security Network Association) request / response, and the authentication process in step S320 can be called the first authentication process, while the security setup process in step S340 can simply be called the authentication process.

[0060] The security setup process in stage S340 may include, for example, a process of private key setup using a four-way handshake with an EAPOL (Extensible Authentication Protocol over LAN) frame. Furthermore, the security setup process may be performed using a security method not defined in the IEEE 802.11 standard.

[0061] Figure 4 is a diagram illustrating the backoff process to which this disclosure can be applied.

[0062] In wireless LAN systems, the basic access mechanism of MAC (Medium Access Control) is the CSMA / CA (Carrier Sense Multiple Access with Collision Avoidance) mechanism. The CSMA / CA mechanism is also called the Distributed Coordination Function (DCF) of IEEE 802.11 MAC, and basically employs a "listen before talk" access mechanism. With this type of access mechanism, an AP and / or STA can perform a Clear Channel Assessment (CCA) to sense the radio channel or medium within a predetermined time interval (e.g., DIFS Inter-Frame Space) before initiating transmission. If the sensing determines that the medium is idle, the AP and / or STA will begin transmitting a frame through that medium. On the other hand, if the medium is perceived as occupied or busy, the AP and / or STA will not begin transmitting itself, but will wait for a delay period (e.g., a random backoff period) for medium access before attempting to transmit a frame. By applying a random backoff period, multiple STAs are expected to attempt to transmit frames after waiting for different periods of time from each other, thus minimizing collisions.

[0063] Furthermore, the IEEE 802.11 MAC protocol provides HCF (Hybrid Coordination Function). HCF is based on the aforementioned DCF and PCF (Point Coordination Function). PCF is a polling-based synchronous access method that periodically polls so that all receiving APs and / or STAs can receive data frames. HCF also has EDCA (Enhanced Distributed Channel Access) and HCCA (HCF Controlled Channel Access). EDCA is a competition-based access method for a provider to provide data frames to multiple users, while HCCA uses a non-competition-based channel access method with a polling mechanism. In addition, HCF includes a media access mechanism to improve the QoS (Quality of Service) of wireless LANs and can transmit QoS data during both the Contention Period (CP) and the Contention Free Period (CFP).

[0064] Refer to Figure 4 to explain the operation based on the random backoff period. When a medium that was occupied / busy changes to idle, multiple STAs can attempt to transmit data (or frames). As a way to minimize collisions, each STA can select a random backoff count and wait for the corresponding slot time before attempting to transmit. The random backoff count has a pseudo-random integer value and may be determined to any one of the values ​​in the range of 0 to CW, where CW is the Contention Window parameter value. The CW parameter is initially given as CWmin, but can take twice that value in case of transmission failure (e.g., if an ACK for a transmitted frame is not received). When the CW parameter value becomes CWmax, the STA can attempt to transmit data while maintaining the CWmax value until successful data transmission occurs, at which point it is reset to the CWmin value. The CW, CWmin, and CWmax values ​​are 2 n It is preferable to set it to -1 (n=0,1,2,...).

[0065] Once the random backoff process begins, the STA continues to monitor the media while counting down the backoff slots according to the determined backoff count value. When the media is monitored as occupied, the countdown stops and it waits; when the media becomes idle, the remaining countdown resumes.

[0066] In the example in Figure 4, when a packet to be transmitted reaches the MAC of STA3, STA3 can immediately transmit the frame after confirming that the medium is idle for DIFS only. The remaining STAs monitor the occupied / busy state of the medium and wait. Meanwhile, data to be transmitted may also be generated in STA1, STA2, and STA5. When each STA monitors the medium as idle, after waiting for DIFS only, it can count down the backoff slot using a random backoff count value of its choice. Assume that STA2 selects the minimum backoff count value and STA1 selects the maximum backoff count value. That is, the example illustrates a case where the remaining backoff time for STA5 is shorter than the remaining backoff time for STA1 when STA2 finishes its backoff count and begins transmitting a frame. STA1 and STA5 pause their countdown and wait for a while while STA2 occupies the medium. When STA2's occupation ends and the medium becomes idle again, STA1 and STA5 wait for DIFS only before resuming the paused backoff count. In other words, frame transmission can begin after counting down the remaining backoff slots equal to the remaining backoff time. Since STA5's remaining backoff time was shorter than STA1's, STA5 begins frame transmission. Data to transmit may also occur in STA4 while STA2 is occupying the medium. From STA4's perspective, when the medium becomes idle, it can wait for DIFS, then count down using a random backoff count value of its choosing, and begin frame transmission. The example in Figure 4 shows a case where STA5's remaining backoff time coincidentally matches STA4's random backoff count value, in which case a collision may occur between STA4 and STA5. If a collision occurs, neither STA4 nor STA5 will receive an ACK, and data transmission will fail. In this case, STA4 and STA5 can double their CW value, select a random backoff count value, and then perform the countdown.STA1 waits while the medium is occupied by transmissions from STA4 and STA5. When the medium becomes idle, STA1 waits only for DIFS, and can begin transmitting frames after the remaining backoff time has elapsed.

[0067] As illustrated in Figure 4, data frames are used to transmit data forwarded to higher layers and may be transmitted after a backoff that occurs after DIFS has elapsed, from the time the medium becomes idle. Furthermore, management frames are used to exchange management information that is not forwarded to higher layers and are transmitted after a backoff that occurs after an IFS such as DIFS or PIFS (Point Coordination Function IFS) has elapsed. Subtypes of management frames include beacons, association request / response, re-association request / response, probe request / response, and authentication request / response. Control frames are used to control access to the medium. Subtypes of control frames include RTS (Request-To-Send), CTS (Clear-To-Send), ACK (Acknowledgment), PS-Poll (Power Save-Poll), Block ACK (BlockAck), Block ACK Request (BlockACKReq), NDP Announcement (null data packet announcement), and Trigger. If a control frame is not a response frame to a previous frame, it is sent after a backoff that occurs after DIFS (Distributed Ingress Fault System), and if it is a response frame to a previous frame, it is sent after a short IFS (Shorter Ingress Fault System) without a backoff. The type and subtype of a frame may be identified by the type field and subtype field in the frame control (FC) field.

[0068] A Quality of Service (QoS) STA can transmit a frame after an arbitration IFS (AIFS) for the access category (AC) to which the frame belongs, i.e., after a backoff that occurs after AIFS[i] (where i is a value determined by the AC). Frames for which AIFS[i] is available can be data frames, management frames, or control frames that are not response frames.

[0069] Figure 5 illustrates the CSMA / CA baseframe transmission operation to which this disclosure can be applied.

[0070] As mentioned earlier, the CSMA / CA mechanism includes not only physical carrier sensing, where the STA directly senses the medium, but also virtual carrier sensing. Virtual carrier sensing is intended to compensate for problems that can occur in medium access, such as the hidden node problem. For virtual carrier sensing, the STA's MAC can utilize the Network Allocation Vector (NAV). The NAV is a value that indicates to other STAs the time remaining until the medium becomes available, used by an STA that is currently using or authorized to use the medium. Therefore, the value set as the NAV corresponds to the period during which the STA sending the frame is scheduled to use the medium, and STAs receiving the NAV value are prohibited from accessing the medium during that period. For example, the NAV may be set based on the value of the "duration" field in the frame's MAC header.

[0071] In the example shown in Figure 5, we assume that STA1 is attempting to transmit data to STA2, and STA3 is in a position where it can overhear some or all of the frames transmitted and received between STA1 and STA2.

[0072] In CSMA / CA baseframe transmission operation, a mechanism utilizing RTS / CTS frames may be applied to reduce the possibility of collisions between transmissions from multiple STAs. In the example in Figure 5, while STA1 is transmitting, carrier sensing by STA3 may determine that the medium is idle. That is, STA1 may be a hidden node for STA3. Alternatively, in the example in Figure 5, while STA2 is transmitting, carrier sensing by STA3 may determine that the medium is idle. That is, STA2 may be a hidden node for STA3. By exchanging RTS / CTS frames before data transmission and reception between STA1 and STA2, it is possible to prevent STAs outside the transmission range of either STA1 or STA2, or STAs outside the carrier sensing range for transmissions from STA1 or STA3, from attempting to occupy the channel during data transmission and reception between STA1 and STA2.

[0073] Specifically, STA1 can determine whether a channel is in use or not using carrier sensing. In terms of physical carrier sensing, STA1 can determine the channel's occupied or idle state based on the energy magnitude or signal correlation detected from the channel. In terms of virtual carrier sensing, STA1 can determine the channel's occupied state using a network allocation vector (NAV) timer.

[0074] STA1 can send an RTS frame to STA2 after backoff if the channel is idle during DIFS. STA2, upon receiving an RTS frame, can send a CTS frame, which is a response to the RTS frame, to STA1 after SIFS.

[0075] If STA3 cannot overhear CTS frames from STA2 but can overhear RTS frames from STA1, STA3 can use the duration information contained in the RTS frames to set the NAV timer for subsequent consecutive frame transmission periods (e.g., SIFS + CTS frame + SIFS + data frame + SIFS + ACK frame). Alternatively, if STA3 cannot overhear RTS frames from STA1 but can overhear CTS frames from STA2, STA3 can use the duration information contained in the CTS frames to set the NAV timer for subsequent consecutive frame transmission periods (e.g., SIFS + data frame + SIFS + ACK frame). In other words, STA3 can set NAV based on overhearing one or more RTS or CTS frames from at least one of STA1 or STA2. If STA3 receives a new frame before the NAV timer expires, it can update the NAV timer using the duration information contained in the new frame. STA3 will not attempt to access the channel until the NAV timer expires.

[0076] When STA1 receives a CTS frame from STA2, it can send a data frame to STA2 after SIFS from the time it has finished receiving the CTS frame. If STA2 successfully receives the data frame, it can send an ACK frame, which is a response to the data frame, to STA1 after SIFS. When the NAV timer expires, STA3 can use carrier sensing to determine whether or not the channel is in use. If STA3 determines that the channel is not being used by another terminal between the expiration of the NAV timer and DIFS, it can attempt to access the channel after the random backoff conflict window (CW) has passed.

[0077] Figure 6 is a diagram illustrating an example of a frame structure used in a wireless LAN system to which this disclosure can be applied.

[0078] The PHY layer can prepare the MPDU (MAC PDU) to be transmitted based on instructions or primitives (meaning a set of instructions or parameters) from the MAC layer. For example, when the PHY layer receives an instruction from the MAC layer requesting it to start transmitting, it switches to transmit mode and can assemble the information provided by the MAC layer (e.g., data) into a frame and transmit it. Also, when the PHY layer detects a valid preamble in the frame it is receiving, it monitors the preamble header and sends an instruction to the MAC layer to signal that the PHY layer has started receiving.

[0079] Thus, information transmission and reception in wireless LAN systems are performed in the form of frames, and for this purpose, the Physical Layer Protocol Data Unit (PPDU) frame format is defined.

[0080] A basic PPDU frame may include an STF (Short Training Field), an LTF (Long Training Field), a SIG (SIGNAL) field, and a Data field. The most basic (e.g., non-HT (High Throughput)) PPDU frame format may consist only of an L-STF (Legacy-STF), an L-LTF (Legacy-LTF), a SIG field, and a Data field. Depending on the type of PPDU frame format (e.g., HT-mixed format PPDU, HT-greenfield format PPDU, VHT (Very High Throughput) PPDU, etc.), additional (or other types of) STF, LTF, and SIG fields may be included between the SIG field and the Data field (see Figure 7 below for further details).

[0081] STF is a signal used for signal detection, AGC (Automatic Gain Control), diversity selection, and precise time synchronization, while LTF is a signal used for channel estimation and frequency error estimation. In essence, STF and LTF are signals for synchronizing the OFDM physical layer and for channel estimation.

[0082] The SIG field may include fields such as the RATE field and the LENGTH field. The RATE field may contain information about the modulation and coding rate of the data. The LENGTH field may contain information about the length of the data. Furthermore, the SIG field may include a parity bit, a SIG TAIL bit, and so on.

[0083] The data field may include a SERVICE field, a PSDU (Physical Layer Service Data Unit), and PPDU TAIL bits, and may also include padding bits if necessary. Some bits of the SERVICE field may be used for synchronizing the descramble at the receiving end. The PSDU corresponds to the MAC PDU defined in the MAC layer and may contain data generated / used in higher layers. The PPDU TAIL bits may be used to return the encoder to a 0 state. Padding bits may be used to adjust the length of the data field to a predetermined unit.

[0084] MAC PDUs are defined by various MAC frame formats, and a basic MAC frame consists of a MAC header, frame body, and FCS (Frame Check Sequence). MAC frames are composed of MAC PDUs and may be transmitted / received by PSDUs, which are the data portion of the PPDU frame format.

[0085] The MAC header includes fields such as Frame Control, Duration / ID, and Address. The Frame Control field may contain control information necessary for transmitting / receiving frames. The Duration / ID field may be set to the time required to transmit the frame. For specific details on the Sequence Control, QoS Control, and HT Control subfields of the MAC header, refer to the IEEE 802.11 standard document.

[0086] The Null Data Packet (NDP) frame format refers to a frame format that does not include data packets. That is, an NDP frame is a frame format that includes the PLCP (Physical Layer Convergence Procedure) header portion (i.e., the STF, LTF, and SIG fields) of a typical PPDU frame format, but omits the remaining portion (i.e., the data fields). NDP frames can also be referred to as short frame formats.

[0087] Figure 7 shows an example of a PPDU as defined in the IEEE 802.11 standard to which this disclosure applies.

[0088] Standards such as IEEE 802.11a / g / n / ac / ax use various forms of PPDU. The basic PPDU format (IEEE 802.11a / g) includes L-LTF, L-STF, L-SIG, and Data fields. The basic PPDU format can also be referred to as the non-HT PPDU format.

[0089] The HT PPDU format (IEEE 802.11n) further includes the HT-SIG, HT-STF, and HT-LFT(s) fields in addition to the basic PPDU format. The HT PPDU format shown in Figure 7 can be called the HT-mixed format. The HT-greenfield format PPDU may be further defined, which does not include L-STF, L-LTF, and L-SIG, and consists of the HT-GF-STF, HT-LTF1, HT-SIG, one or more HT-LTF, and Data fields (not shown).

[0090] An example of the VHT PPDU format (IEEE 802.11ac) is that it further includes the VHT SIG-A, VHT-STF, VHT-LTF, and VHT-SIG-B fields in addition to the basic PPDU format.

[0091] An example of the HE PPDU format (IEEE 802.11ax) further includes the RL-SIG (Repeated L-SIG), HE-SIG-A, HE-SIG-B, HE-STF, HE-LTF(s), and PE (Packet Extension) fields in addition to the basic PPDU format. Depending on the specific example of the HE PPDU format, some fields may be omitted or their lengths may change. For example, the HE-SIG-B field is included in the HE PPDU format for multiple users (MU), while it is not included in the HE PPDU format for single users (SU). Also, the HE trigger-based (TB) PPDU format does not include HE-SIG-B, and the length of the HE-STF field may be changed to 8us. The HE ER (Extended Range) SU PPDU format does not include the HE-SIG-B field, and the length of the HE-SIG-A field may be changed to 16us.

[0092] Figures 8 to 10 illustrate examples of resource units in a wireless LAN system to which this disclosure can be applied.

[0093] Referring to Figures 8 to 10, a resource unit (RU) defined in a wireless LAN system will be explained. An RU may contain multiple subcarriers (or tones). An RU may be used when transmitting a signal to multiple STAs based on the OFDMA method. An RU may also be defined when transmitting a signal to a single STA. An RU may be used for the STF, LTF, data field, etc., of a PPDU.

[0094] As shown in Figures 8 to 10, RUs corresponding to different numbers of tones (i.e., subcarriers) can be used to constitute some fields of a 20MHz, 40MHz, or 80MHz X-PPDU (where X is HE, EHT, etc.). For example, resources may be allocated in units of RUs shown for the X-STF, X-LTF, and Data fields.

[0095] Figure 8 shows an example of resource unit (RU) configuration used in the 20 MHz bandwidth.

[0096] As shown at the top of Figure 8, 26 units (i.e., units corresponding to 26 tones) may be allocated. Six tones may be used as a guard band in the leftmost band of the 20MHz band, and five tones may be used as a guard band in the rightmost band of the 20MHz band. In addition, seven DC tones may be inserted in the center band, i.e., the DC band, and there may be 26 units corresponding to 13 tones on each side of the DC band. Furthermore, 26, 52, or 106 units may be allocated to the other bands. Each unit may be allocated for the STA or the user.

[0097] The RU configuration in Figure 8 can be used not only for situations involving multiple users (MU) but also for situations involving a single user (SU), in which case it is possible to use one 242 unit as shown at the bottom of Figure 8. In this case, three DC tones may be inserted.

[0098] In the example shown in Figure 8, various sizes of RUs are illustrated, such as 26-RU, 52-RU, 106-RU, and 242-RU, but the specific sizes of such RUs may be reduced or expanded. Therefore, the specific size of each RU (i.e., the number of corresponding tones) is not limited in this disclosure and is illustrative. Also, in this disclosure, the number of RUs within a given bandwidth (e.g., 20, 40, 80, 160, 320 MHz, ...) may differ depending on the size of the RU. The same applies to the example in Figure 8 as to the example in Figure 9 and / or Figure 10 described below, in which the size and / or number of RUs may be changed.

[0099] Figure 9 shows an example of resource unit (RU) configuration used in the 40 MHz bandwidth.

[0100] Just as various sizes of RU were used in the example in Figure 8, 26-RU, 52-RU, 106-RU, 242-RU, 484-RU, etc., may be used in the example in Figure 9. In addition, five DC tones may be inserted at the center frequency, twelve tones may be used as a guard band in the leftmost band of the 40MHz bandwidth, and eleven tones may be used as a guard band in the rightmost band of the 40MHz bandwidth.

[0101] Furthermore, as shown in the figure, 484-RU may be used when it is used for a single user.

[0102] Figure 10 shows an example arrangement of resource units (RUs) used in the 80 MHz bandwidth.

[0103] Just as various sizes of RUs were used in the examples in Figures 8 and 9, 26-RU, 52-RU, 106-RU, 242-RU, 484-RU, 996-RU, etc., may be used in the example in Figure 10. Furthermore, in the 80MHz PPDU, the RU arrangement of the HE PPDU and EHT PPDU may differ from each other, and the example in Figure 10 shows an example of the RU arrangement for the 80MHz EHT PPDU. In the example in Figure 10, the leftmost band of the 80MHz bandwidth uses 12 tones as a guard band, and the rightmost band of the 80MHz bandwidth uses 11 tones as a guard band, which is the same for both the HE PPDU and the EHT PPDU. Unlike the HE PPDU, where seven DC tones are inserted into the DC band and there is one 26-RU on each side of the DC band corresponding to 13 tones, the EHT PPDU has 23 DC tones inserted into the DC band and one 26-RU on both the left and right sides of the DC band. Unlike the HE PPDU, where there is one null subcarrier between 242-RUs that are not in the center band, the EHT PPDU has five null subcarriers. In the HE PPDU, one 484-RU does not contain null subcarriers, but in the EHT PPDU, one 484-RU contains five null subcarriers.

[0104] Furthermore, as shown in the figure, the 996-RU may be used when used for a single user, and in this case, the insertion of five DC tones is common to both the HE PPDU and the EHT PPDU.

[0105] An EHT PPDU of 160MHz or higher may be configured with multiple 80MHz subblocks as shown in Figure 10. The RU configuration for each 80MHz subblock may be the same as the RU configuration for the 80MHz EHT PPDU in Figure 10. When the 80MHz subblock of a 160MHz or 320MHz EHT PPDU is not punctured and the entire 80MHz subblock is used as part of an RU or MRU (Multiple RU), the 80MHz subblock may use RU 996-996 as shown in Figure 10.

[0106] Here, an MRU corresponds to a group of subcarriers (or tones) composed of multiple RUs, and the multiple RUs constituting an MRU may be of the same size or of 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 multiple RUs constituting a single MRU may correspond to small-sized RUs (e.g., 26, 52, 106) or large-sized RUs (e.g., 242, 484, 996, etc.). That is, a single MRU containing both small-sized and large-sized RUs may not be set / defined. Also, the multiple RUs constituting a single MRU may or may not be consecutive in the frequency domain.

[0107] If the 80MHz subblock contains RUs smaller than 996 tones, or if a portion of the 80MHz subblock is punctured, the 80MHz subblock may use an RU arrangement excluding the 996-tone RUs.

[0108] The RUs of this disclosure may be used in uplink (UL) and / or downlink (DL) communication. For example, in the case of trigger-based UL-MU communication, an STA (e.g., AP) transmitting a trigger may use trigger information (e.g., a trigger frame or TRS (triggered response scheduling)) to assign a first RU (e.g., 26 / 52 / 106 / 242-RU, etc.) to a first STA and a second RU (e.g., 26 / 52 / 106 / 242-RU, etc.) to a second STA. The first STA can then transmit a first trigger-based (TB) PPDU based on the first RU, and the second STA can transmit a second TB PPDU based on the second RU. The first and second TB PPDUs may be transmitted to the AP in the same time interval.

[0109] For example, when a DL MU PPDU is configured, the STA (e.g., AP) sending the DL MU PPDU can assign a first RU (e.g., 26 / 52 / 106 / 242-RU) to the first STA and a second RU (e.g., 26 / 52 / 106 / 242-RU) to the second STA. That is, the sending STA (e.g., AP) can use the first RU to send the HE-STF, HE-LTF, and Data fields for the first STA within a single MU PPDU, and use the second RU to send the HE-STF, HE-LTF, and Data fields for the second STA.

[0110] Information regarding the RU's placement may be signaled via HE-SIG-B in HE PPDU format.

[0111] Figure 11 shows an exemplary structure of the HE-SIG-B field.

[0112] As shown in the figure, the HE-SIG-B field may include a common field and a user-specific field. When HE-SIG-B compression is applied (for example, in 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 the user-specific field. When HE-SIG-B compression is not applied, the common field may be included in HE-SIG-B.

[0113] Common fields may include information related to RU allocation (e.g., RU assignment, RUs allocated for MU-MIMO, number of MU-MIMO users (STAs), etc.).

[0114] The common field may contain N*8 RU allocation subfields, where N is the number of subfields, and may have values ​​such as N=1 for 20 or 40MHz MU PPDU, N=2 for 80MHz MU PPDU, N=4 for 160MHz or 80+80MHz MU PPDU, and so on. One 8-bit RU allocation subfield can indicate the size (26, 52, 106, etc.) and frequency position (or RU index) of RUs included in the 20MHz band.

[0115] For example, if the value of the 8-bit RU allocation subfield is 00000000, nine 26-RUs are arranged sequentially from left to right in the example shown in Figure 8. If the value is 00000001, seven 26-RUs and one 52-RU are arranged sequentially from left to right. If the value is 00000010, five 26-RUs, one 52-RU, and two 26-RUs are arranged sequentially from left to right.

[0116] As an additional example, if the value of the 8-bit RU allocation subfield is 01000y2y1y0, then one 106-RU and five 26-RUs are arranged sequentially from left to right in the example in Figure 8. In this case, multiple users / STAs may be assigned to the 106-RU using the MU-MIMO method. Specifically, up to eight users / STAs may be assigned to the 106-RU, and the number of users / STAs assigned to the 106-RU is determined based on the 3-bit information (i.e., y2y1y0). For example, if the 3-bit information (y2y1y0) corresponds to a decimal value N, then the number of users / STAs assigned to the 106-RU may be N+1.

[0117] Basically, one user / STA may be assigned to each of multiple RUs, and different users / STAs may be assigned to different RUs. For RUs of a certain size or larger (e.g., 106, 242, 484, 996-tones, ...), multiple users / STAs may be assigned to a single RU, and the MU-MIMO scheme may be applied to such multiple users / STAs.

[0118] The set of user-specific fields contains information about how all users (STAs) of the PPDU decode their payload. User-specific fields may contain zero or more user block fields. A non-final user block field contains two user fields (i.e., information used for decoding in two STAs). A 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, by the symbol count of HE-SIG-B, or by the MU-MIMO user field of HE-SIG-A. User-specific fields may be encoded separately or independently of common fields.

[0119] Figure 12 is a diagram illustrating the MU-MIMO scheme in which multiple users / STAs are assigned to a single RU.

[0120] In the example in Figure 12, we assume 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 it can be shown that 3 (=N+1) users are assigned to one RU. In this case, one 106-RU and five 26-RUs may be arranged sequentially from the leftmost to the rightmost of a particular 20MHz band / channel. Three users / STAs may be assigned to the 106-RU in a MU-MIMO manner. As a result, a total of 8 users / STAs are assigned to the 20MHz band / channel, and the user-specific field of HE-SIG-B may contain 8 user fields (i.e., 4 user block fields). The 8 user fields may be assigned to RUs as shown in Figure 12.

[0121] User fields may be constructed based on two formats. User fields for MU-MIMO assignments may be constructed in the first format, and user fields for non-MU-MIMO assignments may be constructed in the second format. Referring to an example in Figure 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 and second formats may contain bit information of the same length (e.g., 21 bits).

[0122] The user fields of the first format (i.e., the format for MU-MIMO assignment) may be configured as follows: For example, of the total 21 bits of a single user field, B0 to B10 may contain the user's identification information (e.g., STA-ID, AID, partial AID, etc.), B11 to B14 may contain spatial configuration information such as the number of spatial streams for the user, B15 to B18 may contain MCS (Modulation and coding scheme) information applied to the Data field of the PPDU, B19 may be defined as a reserved field, and B20 may contain coding type information applied to the Data field of the PPDU (e.g., BCC (binary convolutional coding) or LDPC (low-density parity check)).

[0123] The user field of the second format (i.e., the format for non-MU-MIMO assignments) may be configured as follows: For example, of the 21 bits in a single user field, B0 to B10 may contain user identification information (e.g., STA-ID, AID, partial AID, etc.), B11 to B13 may contain spatial stream number (NSTS) information applied to the RU, B14 may contain information indicating whether beamforming is possible (or whether a beamforming steering matrix can be applied), B15 to B18 may contain MCS (Modulation and coding scheme) information applied to the Data field of the PPDU, B19 may contain information indicating whether DCM (dual carrier modulation) can be applied, and B20 may contain coding type information applied to the Data field of the PPDU (e.g., BCC or LDPC).

[0124] The terms MCS, MCS information, MCS index, and MCS field used in this disclosure may be represented by specific index values. For example, MCS information may be represented by index 0 to index 11. MCS information may include information about the alternate modulation type (e.g., BPSK, QPSK, 16-QAM, 64-QAM, 256-QAM, 1024-QAM, etc.) and information about the coding rate (e.g., 1 / 2, 2 / 3, 3 / 4, 5 / 6, etc.). Information about the channel coding type (e.g., BCC or LDPC) may be omitted from the MCS information.

[0125] Figure 13 shows examples of PPDU formats to which this disclosure can be applied.

[0126] The PPDU in Figure 13 may be referred to by various names such as EHT PPDU, Transmit PPDU, Receive PPDU, Type 1 or Type N PPDU. For example, the PPDU or EHT PPDU of this disclosure can be referred to by various names such as Transmit PPDU, Receive PPDU, Type 1 or Type N PPDU. Furthermore, the EHT PPU can be used in EHT systems and / or new wireless LAN systems that improve upon EHT systems.

[0127] The EHT MU PPDU in Figure 13 corresponds to a carry PPDU that carries one or more data (or PSDUs) for one or more users. In other words, the EHT MU PPDU may be used for either SU transmissions or MU transmissions. For example, the EHT MU PPDU may correspond to a PPDU for one or more receiving STAs.

[0128] In Figure 13, the EHT TB PPDU omits the EHT-SIG compared to the EHT MU PPDU. An STA that receives a trigger for UL MU transmission (e.g., a trigger frame or TRS) can perform the UL transmission based on the EHT TB PPDU format.

[0129] In the example of the EHT PPDU format shown in Figure 13, L-STF to EHT-LTF correspond to the preamble or physical preamble and may be generated / transmitted / received / acquired / decoded at the physical layer.

[0130] The subcarrier frequency spacing for L-STF, L-LTF, L-SIG, RL-SIG, U-SIG (Universal SIGNAL), and EHT-SIG fields (collectively referred to as pre-EHT modulated fields) may be set to 312.5 kHz. The subcarrier frequency spacing for EHT-STF, EHT-LTF, Data, and PE fields (collectively referred to as EHT modulated fields) may be set to 78.125 kHz. In other words, the tone / subcarrier index for L-STF, L-LTF, L-SIG, RL-SIG, U-SIG, and EHT-SIG fields may be displayed in units of 312.5 kHz, while the tone / subcarrier index for EHT-STF, EHT-LTF, Data, and PE fields may be displayed in units of 78.125 kHz.

[0131] The L-LTF and L-STF in Figure 13 may be configured identically to the corresponding fields of the PPDU described in Figures 6 and 7.

[0132] The L-SIG field in Figure 13 consists of 24 bits and may be used to communicate rate and length information. For example, the L-SIG field may include a 4-bit Rate field, a 1-bit Reserved bit, a 12-bit Length field, a 1-bit Parity field, and a 6-bit Tail field. For example, the 12-bit Length field may contain information about the length or time duration of the PPDU. For example, the value of the 12-bit Length field may be determined based on the type of PPDU. For example, for non-HT, HT, VHT, or EHT PPDUs, the value of the Length field may be determined to be a multiple of 3. For example, for HE PPDUs, the value of the Length field may be determined to be a multiple of 3 + 1 or a multiple of 3 + 2.

[0133] For example, a transmitting STA can apply BCC encoding based on half the coding rate to 24 bits of information in the L-SIG field. The transmitting STA can then obtain 48 bits of BCC encoded bits. BPSK modulation may be applied to the 48 bits of encoded bits to generate 48 BPSK symbols. The transmitting STA can map the 48 BPSK symbols to positions excluding the pilot subcarrier (e.g., {subcarrier indices -21, -7, +7, +21}) and the DC subcarrier (e.g., {subcarrier index 0}). Consequently, the 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 can further map the signal {-1, -1, -1, 1} to subcarrier indices {-28, -27, +27, +28}. The signal may be used for channel estimation in the frequency domain corresponding to {-28, -27, +27, +28}.

[0134] The transmitting STA can generate an RL-SIG that is generated identically to the L-SIG. BPSK modulation is applied to the RL-SIG. Based on the presence of the RL-SIG, the receiving STA can determine that the received PPDU is either an HE PPDU or an EHT PPDU.

[0135] A U-SIG (Universal SIG) may be inserted after the RL-SIG in Figure 13. The U-SIG can be named in various ways, such as first SIG field, first SIG, first type SIG, control signal, control signal field, or first (type) control signal.

[0136] A U-SIG may contain N bits of information, including information to identify the type of EHT PPDU. For example, a U-SIG may consist of two symbols (e.g., two consecutive OFDM symbols). Each symbol for the U-SIG (e.g., an OFDM symbol) may have a duration of 4us, and the U-SIG may have a total duration of 8us. Each symbol of the U-SIG may be used to transmit 26 bits of information. For example, each symbol of the U-SIG may be transmitted and received based on 52 data tones and 4 pilot tones.

[0137] In a U-SIG (or U-SIG field), for example, A-bit information (e.g., 52 uncoded bits) may be transmitted. The first symbol of the U-SIG (e.g., U-SIG-1) may transmit the first X bits of the total A-bit information (e.g., 26 uncoded bits), and the second symbol of the U-SIG (e.g., U-SIG-2) may transmit the remaining Y bits of the total A-bit information (e.g., 26 uncoded bits). For example, a transmitting STA can obtain the 26 uncoded bits contained in each U-SIG symbol. The transmitting STA can perform convolution encoding (e.g., BCC encoding) based on a rate of R=1 / 2 to generate 52-coded bits and perform interleaving on the 52-coded bits. The transmitting STA can perform BPSK modulation on the interleaved 52-coded bits to generate 52 BPSK symbols to be assigned to each U-SIG symbol. A single U-SIG symbol may be transmitted based on 56 tones (subcarriers) from subcarrier index -28 to subcarrier index +28, excluding DC index 0. The 52 BPSK symbols generated by the transmitting STA may be transmitted based on the remaining tones (subcarriers), excluding the pilot tones -21, -7, +7, and +21.

[0138] For example, the A-bit information transmitted by the U-SIG (e.g., 52 uncoded bits) may include a CRC field (e.g., a 4-bit field) and a tail field (e.g., a 6-bit field). The CRC field and tail field may be transmitted in a second symbol of the U-SIG. The CRC field may be generated based on 26 bits assigned to the first symbol of the U-SIG and the remaining 16 bits in the second symbol excluding the CRC / tail field, and may be generated based on a conventional CRC calculation algorithm. The tail field may also be used to terminate the trellis of the convolution decoder and may be set to 0, for example.

[0139] The A-bit information transmitted by the U-SIG (or U-SIG field) (e.g., 52 uncoded bits) can be distinguished into version-independent bits and version-dependent bits. For example, the size of the version-independent bits may be fixed or variable. For example, the version-independent bits may be assigned only to the first symbol of the U-SIG, or they may be assigned to both the first and second symbols of the U-SIG. For example, the version-independent bits and version-dependent bits may have various names, such as first control bits and second control bits.

[0140] 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 contain information about the physical layer version (PHY version) of the transmitted and received PPDUs. For example, the first value of the 3-bit PHY version identifier can indicate that the transmitted and received PPDUs are EHT PPDUs. In other words, a transmitting STA can set the 3-bit PHY version identifier to the first value when transmitting an EHT PPDU. In other words, a receiving STA can determine that the received PPDU is an EHT PPDU based on the PHY version identifier having the first value.

[0141] For example, the version-independent bits of a U-SIG may include a 1-bit UL / DL flag field. The first value of the 1-bit UL / DL flag field is related to UL communication, and the second value of the UL / DL flag field is related to DL communication.

[0142] For example, the version-independent bits of the U-SIG may include information about the length of the TXOP (transmission opportunity) and information about the BSS color ID.

[0143] For example, if EHT PPDUs are categorized into various types (e.g., EHT PPDUs associated with SU mode, EHT PPDUs associated with MU mode, EHT PPDUs associated with TB mode, EHT PPDUs associated with Extended Range transmission, etc.), information regarding the type of EHT PPDU may be included in version-dependent bits of the U-SIG.

[0144] For example, a U-SIG may include information about: 1) a bandwidth field containing information about bandwidth; 2) a field containing information about the MCS method applied to the EHT-SIG; 3) an indication field containing information about whether or not the DCM method is applied to the EHT-SIG; 4) a field containing information about the number of symbols used for the EHT-SIG; 5) a field containing information about whether or not the EHT-SIG is generated across the entire bandwidth; 6) a field containing information about the type of EHT-LTF / STF; and 7) fields indicating the length of the EHT-LTF and the CP length.

[0145] Preamble puncturing may be applied to the PPDU in Figure 13. Preamble puncturing can mean the transmission of a PPDU in which one or more 20 MHz subchannels within the PPDU's bandwidth are not present. Preamble puncturing may be applied to PPDUs transmitted to one or more users. For example, the resolution of preamble puncturing may be 20 MHz for EHT MU PPDUs in OFDMA transmissions with bandwidths greater than 40 MHz and non-OFDMA transmissions with bandwidths of 80 MHz and 160 MHz. In other words, in the above case, puncturing of subchannels smaller than 242 tone RUs may not be permitted. Also, for EHT MU PPDUs in non-OFDMA transmissions with a bandwidth of 320 MHz, the resolution of preamble puncturing may be 40 MHz. In other words, puncturing of subchannels smaller than 484 tone RUs in a 320 MHz bandwidth may not be permitted. Furthermore, in EHT MU PPDU, preamble puncturing does not need to be applied to the primary 20MHz channel.

[0146] For example, for an EHT MU PPDU, information regarding preamble puncturing may be included in the U-SIG and / or EHT-SIG. For instance, the first field of the U-SIG may include information regarding the contiguous bandwidth of the PPDU, and the second field of the U-SIG may include information regarding the preamble puncturing applied to the PPDU.

[0147] For example, the U-SIG and EHT-SIG may include information about preamble puncturing based on the following method. If the bandwidth of the PPDU exceeds 80 MHz, the U-SIGs may be configured individually in 80 MHz units. For example, if the bandwidth of the PPDU is 160 MHz, the PPDU may include a first U-SIG for the first 80 MHz band and a second U-SIG for the second 80 MHz band. In this case, the first field of the first U-SIG may include information about the 160 MHz bandwidth, and the second field of the first U-SIG may include information about preamble puncturing applied to the first 80 MHz band (i.e., information about the preamble puncturing pattern). The first field of the second U-SIG may include information about the 160 MHz bandwidth, and the second field of the second U-SIG may include information about preamble puncturing applied to the second 80 MHz band (i.e., information about the preamble puncturing pattern). An EHT-SIG following the first U-SIG may include information about preamble puncturing applied to the second 80 MHz band (i.e., information about the preamble puncturing pattern), and an EHT-SIG following the second U-SIG may include information about preamble puncturing applied to the first 80 MHz band (i.e., information about the preamble puncturing pattern).

[0148] As an addition or alternative, the U-SIG and EHT-SIG may include information on preamble puncturing based on the following methods: The U-SIG may include information on preamble puncturing for the entire bandwidth (i.e., information on the preamble puncturing pattern). That is, the EHT-SIG may not include information on preamble puncturing, and only the U-SIG may include information on preamble puncturing (i.e., information on the preamble puncturing pattern).

[0149] U-SIGs may be configured in 20MHz units. For example, when an 80MHz PPDU is configured, U-SIGs may be duplicated. That is, an 80MHz PPDU may contain four identical U-SIGs. PPDUs with a bandwidth exceeding 80MHz may contain different U-SIGs.

[0150] The EHT-SIG in Figure 13 may contain control information for the receiving STA. The EHT-SIG may be transmitted with at least one symbol, which may have a length of 4us. Information regarding the number of symbols used for the EHT-SIG may be included in the U-SIG.

[0151] The EHT-SIG may include the technical features of the HE-SIG-B described in Figures 11 and 12. For example, the EHT-SIG may include common fields and user-specific fields, identical to the example in Figure 8. The common fields of the EHT-SIG may be omitted, and the number of user-specific fields may be determined based on the number of users.

[0152] As in the example in Figure 11, the common fields and user-specific fields of the EHT-SIG may be coded separately. One user block field included in the user-specific field contains 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 a maximum of two user fields. As in the example in Figure 12, each user field may be related to MU-MIMO assignment or non-MU-MIMO assignment.

[0153] Similar to the example in Figure 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 to be 4 bits, and the length of the Tail bit may be determined to be 6 bits and set to 000000.

[0154] As in the example shown in Figure 11, the common fields of the EHT-SIG may include RU allocation information. RU allocation information can represent information about the location of RUs to which multiple users (i.e., multiple receiving STAs) are assigned. RU allocation information may consist of 8-bit (or N-bit) units.

[0155] A mode in which the common field of the EHT-SIG is omitted may be supported. This mode in which the common field of the EHT-SIG is omitted can be called compressed mode. When compressed mode is used, multiple users of the EHT PPDU (i.e., multiple receiving STAs) can decode the PPDU (e.g., the data field of the PPDU) based on non-OFDMA. That is, multiple users of the EHT PPDU can decode the PPDU (e.g., the data field of the PPDU) received in the same frequency band. When non-compressed mode is used, multiple users of the EHT PPDU can decode the PPDU (e.g., the data field of the PPDU) based on OFDMA. That is, multiple users of the EHT PPDU can receive the PPDU (e.g., the data field of the PPDU) in different frequency bands.

[0156] The EHT-SIG may be constructed based on various MCS techniques. As mentioned above, information regarding the MCS technique applied to the EHT-SIG may be included in the U-SIG. The EHT-SIG may be constructed based on the DCM technique. The DCM technique can reuse the same signal on two subcarriers to provide an effect similar to frequency diversity, reducing interference and improving coverage. For example, modulation symbols with the same modulation technique applied may be repeatedly mapped on available tones / subcarriers. For example, of the N data tones allocated for the EHT-SIG (e.g., 52 data tones), the first half of the tones (e.g., tones 1-26) may be mapped to modulation symbols with a specific modulation technique applied (e.g., BPSK modulation symbols), and the remaining half of the tones (e.g., tones 27-52) may be mapped to modulation symbols with the same specific modulation technique applied (e.g., BPSK modulation symbols). That is, the modulation symbol mapped to the first tone and the modulation symbol mapped to the 27th tone will be the same. As described above, information related to whether or not the DCM method is applied to the EHT-SIG (e.g., a 1-bit field) may be included in the U-SIG. The EHT-STF in Figure 13 may be used to improve automatic gain control (AGC) estimation in MIMO or OFDMA environments. The EHT-LTF in Figure 13 may be used to estimate the channel in MIMO or OFDMA environments.

[0157] Information regarding the type of STF and / or LTF (including information regarding the GI (guard interval) applied to the LTF) may be included in the U-SIG field and / or EHT-SIG field in Figure 13, etc.

[0158] The PPDU in Figure 13 (i.e., the EHT PPDU) may be configured based on the example RU configurations in Figures 8 to 10.

[0159] For example, an EHT PPDU transmitted over a 20MHz bandwidth, i.e., a 20MHz EHT PPDU, may be configured based on the RUs in Figure 8. That is, the locations of the RUs for the EHT-STF, EHT-LTF, and data field included in the EHT PPDU may be determined as shown in Figure 8. An EHT PPDU transmitted over a 40MHz bandwidth, i.e., a 40MHz EHT PPDU, may be configured based on the RUs in Figure 9. That is, the locations of the RUs for the EHT-STF, EHT-LTF, and data field included in the EHT PPDU may be determined as shown in Figure 9.

[0160] An EHT PPDU transmitted over the 80MHz band, i.e., an 80MHz EHT PPDU, may be constructed based on the RUs in Figure 10. That is, the locations of the RUs for the EHT-STF, EHT-LTF, and data field included in the EHT PPDU may be determined as shown in Figure 10. The tone-plan for 80MHz in Figure 10 may correspond to two iterations of the tone-plan for 40MHz in Figure 9.

[0161] The tone plan for 160 / 240 / 320MHz may consist of multiple repetitions of the pattern shown in Figure 9 or Figure 10.

[0162] The PPDU in Figure 13 may be identified as an EHT PPDU based on the following method.

[0163] The receiving STA can determine the type of the received PPDU to be an EHT PPDU based on the following: For example, the received PPDU may be determined to be an EHT PPDU if 1) the first symbol after the L-LTF signal of the received PPDU is BPSK, 2) an RL-SIG is detected in which the L-SIG of the received PPDU is repeated, and 3) the result of applying modulo 3 to the value of the Length field of the L-SIG of the received PPDU (i.e., the remainder when divided by 3) is detected to be 0. When the received PPDU is determined to be an EHT PPDU, the receiving STA can determine the type of the EHT PPDU based on the bit information contained in the symbol after the RL-SIG in Figure 13. In other words, the receiving STA can determine the received PPDU to be an EHT PPDU based on 1) the first symbol after the L-LTF signal which is BSPK, 2) an RL-SIG that is consecutive to the L-SIG field and identical to the L-SIG, and 3) an L-SIG that contains a Length field in which the result of applying modulo 3 is set to 0.

[0164] For example, a receiving STA can determine the type of the received PPDU to be HE PPDU based on the following: For example, if 1) the first symbol after the L-LTF signal is BPSK, 2) an RL-SIG consisting of repeated L-SIGs is detected, and 3) the result of applying modulo 3 to the Length value of the L-SIG is detected to be 1 or 2, then the received PPDU may be determined to be HE PPDU.

[0165] For example, a receiving STA can determine the type of the received PPDU to be non-HT, HT, or VHT PPDU based on the following: For example, if 1) the first symbol after the L-LTF signal is BPSK, and 2) no RL-SIG (where L-SIG is repeated) is detected, the received PPDU may be determined to be non-HT, HT, or VHT PPDU.

[0166] Furthermore, if the receiving STA detects an RL-SIG in which the L-SIG is repeated from the received PPDU, it can determine that it is an HE PPDU or an EHT PPDU. In this case, if the rate (6Mbps) check fails, the received PPDU may be determined to be a non-HT, HT, or VHT PPDU. If the rate (6Mbps) check and parity check pass, and the result of applying modulo 3 to the Length value of the L-SIG is detected as 0, the received PPDU may be determined to be an EHT PPDU; if the result of Length mod 3 is not 0, it may be determined to be an HE PPDU.

[0167] The PPDU in Figure 13 may be used to send and receive various types of frames. For example, the PPDU in Figure 13 may be used for the simultaneous transmission and reception of one or more control frames, management frames, or data frames.

[0168] PPDU for wide bandwidth

[0169] Compared to existing wireless LAN systems that support a maximum bandwidth of 320 MHz, it is possible to define and support wider bandwidths for improved throughput, efficiency, and other benefits. For example, wider bandwidths may be defined as various sizes such as 640 MHz and 480 MHz. Existing PPDU types / formats cannot be applied to transmissions over such wider bandwidths, and new PPDU types / formats for wider bandwidths need to be defined. For example, a 480 MHz bandwidth may be defined as a 640 MHz bandwidth with some subchannels punctured or disabled, or it may be defined as a new bandwidth distinct from 640 MHz.

[0170] As mentioned above, various PPDU types / formats are defined in existing wireless LAN systems. The MU PPDU format may be applied to UL transmissions addressed to APs or DL ​​transmissions addressed to non-AP STAs, and the MU PPDU may be configured such that one or more fields / subfields differ from each other depending on whether it is OFDMA or non-OFDMA type. Non-OFDMA transmissions may include SU transmissions and MU-MIMO transmissions. The TB PPDU format based on trigger frames may be applied to UL transmissions addressed to APs.

[0171] The PPDU for wide bandwidths to which this disclosure can be applied may also be applied to UL transmission and / or DL ​​transmission, and may be applied to OFDMA type and non-OFDMA type as multiple access schemes.

[0172] Furthermore, while an AP may have the capacity to support a wide bandwidth, a non-AP STA may or may not support a wide bandwidth. In other words, this disclosure also considers cases where a non-AP STA has the capacity to support transmission / reception only on bandwidths below the bandwidth defined in existing wireless LANs (e.g., 320 MHz bandwidth). For example, a non-AP STA may not be able to perform non-OFDMA transmission / reception using the entire wide bandwidth (e.g., 640 MHz, 480 MHz bandwidth), but may be assigned to a RU corresponding to a portion of the wide bandwidth (e.g., 320 MHz), and can perform non-OFDMA transmission / reception on that RU.

[0173] The following examples assume DL non-OFDMA transmission within a portion of a broad bandwidth frequency unit and describe a new PPDU type / format that supports it. However, the examples in this disclosure are not limited to OFDMA or non-OFDMA type transmission / reception of the DL MU PPDU format, but may also apply to UL transmission / reception and / or OFDMA transmission / reception, etc. Furthermore, the names of the PPDU formats / types for broad bandwidths relating to this disclosure are illustrative, and the scope of this disclosure is not limited by such illustrative names.

[0174] Figure 14 is a diagram illustrating an example of a PPDU transmission method for a wide bandwidth according to this disclosure.

[0175] In step S1410, the first STA can generate a first-type or second-type PPDU based on the multiple access type in the first frequency unit and the second frequency unit, respectively.

[0176] The first and second frequency units may correspond to multiple frequency units (e.g., channels / subchannels / RUs) that constitute a wide bandwidth. The relative positions of the first and second frequency units in the frequency domain are not limited (e.g., the first frequency unit may correspond to lower frequency positions or higher frequency positions), and they may be continuous or not. The first frequency unit may correspond to a primary channel and the second frequency unit to a secondary channel, or the first frequency unit may correspond to a secondary channel and the second frequency unit to a primary channel.

[0177] For example, the first frequency unit may correspond to a 320 MHz channel / subchannel (or a set of one or more RUs corresponding thereto), and the second frequency unit may correspond to a 320 MHz channel / subchannel (or a set of one or more RUs corresponding thereto). In this case, the bandwidth including the first and second frequency units may be 640 MHz.

[0178] Alternatively, the first frequency unit may correspond to a 320 MHz channel / subchannel (or a set of one or more RUs corresponding thereto), and the second frequency unit may correspond to a 160 MHz channel / subchannel (or a set of one or more RUs corresponding thereto). Alternatively, the first frequency unit may correspond to a 160 MHz channel / subchannel (or a set of one or more RUs corresponding thereto), and the second frequency unit may correspond to a 320 MHz channel / subchannel (or a set of one or more RUs corresponding thereto). In this case, the bandwidth including the first and second frequency units may be 480 MHz.

[0179] The PPDU type may be based on the multiple access type in the first and second frequency units, respectively. For example, if both the multiple access type for the first frequency unit and the multiple access type for the second frequency unit are of type 1, it may correspond to a type 1 PPDU. Alternatively, if either the multiple access type for the first frequency unit or the multiple access type for the second frequency unit is of type 2, it may correspond to a type 2 PPDU.

[0180] For example, Type 1 may be classified as a non-OFDMA, while Type 2 may be classified as an OFDMA.

[0181] When the PPDU types are different, the format / content of one or more fields constituting the non-legacy preamble may be different from each other. Here, the non-legacy preamble may correspond to the remaining preamble fields in the PHY preamble (e.g., RL-SIG, U-SIG, and non-legacy SIG, non-legacy STF, non-legacy LTF, etc.) excluding the legacy fields (L-STF, L-LTF, L-SIG fields in the example in Figure 13). The term non-legacy may be replaced with the term UHR, but this disclosure is not limited by this name and may be replaced with a term referring to a format not defined in existing wireless LAN systems. Furthermore, the non-legacy preamble fields may include pre-UHR modulated fields (e.g., RL-SIG, U-SIG, etc.) and UHR modulated fields (e.g., UHR-SIG, UHR-STF, UHR-LTF, etc.). The legacy preamble may correspond to a pre-UHR modulated field.

[0182] The first SIG (e.g., U-SIG) fields included in the non-legacy preamble of the PPDU relating to this disclosure may have different formats depending on the PPDU type.

[0183] For example, in the case of a first-type (or non-OFDMA) PPDU, the first SIG may contain information that is distinct in the first frequency unit and the second frequency unit, and the same information may be contained within each frequency unit. For example, if the frequency unit size exceeds 20 MHz, the same information may be contained in each of the multiple 20 MHz units within a single frequency unit.

[0184] For example, in the case of a Type 2 (or OFDMA) PPDU, the first SIG may contain information that distinguishes each 80 MHz frequency subunit (or subchannel) within the bandwidth, and each 80 MHz frequency subunit may contain the same information. For example, each of the four 20 MHz units within an 80 MHz frequency subunit may contain the same information.

[0185] Regardless of the PPDU type or for a specific PPDU type, the first SIG field included in the non-legacy preamble may contain one or more pieces of information indicating the PPDU type or information regarding the bandwidth size.

[0186] The second SIG (e.g., non-legacy SIG field, or UHR-SIG) fields included in the non-legacy preamble of the PPDU relating to this disclosure may have different formats depending on the PPDU type.

[0187] For example, in the case of a first-type (or non-OFDMA) PPDU, the second SIG may contain information that is distinct in the first frequency unit and the second frequency unit, and the same information may be contained within each frequency unit. For example, if the frequency unit size exceeds 20 MHz, the same information may be contained in each of the multiple 20 MHz units within a single frequency unit.

[0188] For example, in the case of a second-type (or OFDMA) PPDU, the second SIG may contain information that is alternately distinguished for each frequency subunit (e.g., 20 MHz units) within the bandwidth. For example, across the entire bandwidth, the first content channel of the second SIG may be mapped to odd-numbered 20 MHz units, and the second content channel of the second SIG may be mapped to even-numbered 20 MHz units. Such examples may apply regardless of whether subchannel selective transmission (SST) is applied. For example, SST operation may include determining a subchannel or RU for frame exchange between the transmitting and receiving ends and performing frame exchange in that subchannel / RU for a predetermined period.

[0189] For example, in the case of a Type 2 (or OFDMA) PPDU, the second SIG may contain information that is distinguishable within the first and second frequency units, and within each frequency unit, it may contain information that is alternately distinguishable for each frequency subunit (e.g., 20 MHz units). For example, within the first frequency unit, the first content channel of the second SIG may be mapped to the odd-numbered 20 MHz units, and the second content channel of the second SIG may be mapped to the even-numbered 20 MHz units. For example, within the second frequency unit, the third content channel of the second SIG may be mapped to the odd-numbered 20 MHz units, and the fourth content channel of the second SIG may be mapped to the even-numbered 20 MHz units. Such examples may also apply when SST is applied to the first or second frequency unit.

[0190] Regardless of the PPDU type or for a specific PPDU type, sequences applied to one or more STF (e.g., UHR-STF) or LTF (e.g., UHR-LTF) fields included in a non-legacy preamble may be defined as having a length corresponding to the bandwidth size. Additionally or alternatively, sequences applied to non-legacy STF / LTF may be defined as having a length corresponding to the size of the first frequency unit. Additionally or alternatively, sequences applied to non-legacy STF / LTF may be defined as having a length corresponding to the size of the second frequency unit. Additionally or alternatively, sequences applied to non-legacy STF / LTF may be defined as having a length corresponding to a frequency subunit size smaller than the first or second frequency unit (e.g., the size corresponding to the remaining subunits when some frequency subunits in the first / second frequency unit are punctured / disabled). Non-legacy STF sequences and / or non-legacy LTF sequences defined in this way may be mapped to subcarriers at predefined positions for each.

[0191] Regardless of the PPDU type or for a specific PPDU type, the number of symbols in the non-legacy LTF field may be the same across the entire bandwidth. That is, the number of symbols in the PPDU's LTF field may be the maximum of the number of LTF field symbols required in the first frequency unit and the number of LTF field symbols required in the second frequency unit. Also, the number of LTF field symbols required in the first or second frequency unit may be the maximum of the number of LTF field symbols required in multiple different frequency subbands within each frequency unit.

[0192] Regardless of the PPDU type, or for a specific PPDU type, the start and end points of the PPDU may be set identically across the entire bandwidth. To this end, if necessary, a specific field / symbol / padding, such as a subsequent PE (packet extension), may be appended to the PPDU data field in zero or greater numbers per frequency unit / frequency subunit.

[0193] In step S1420, the first STA can transmit PPDUs to one or more second STAs over a bandwidth including the first and second frequency units.

[0194] Figure 15 is a diagram illustrating an example of a PPDU reception method for a wide bandwidth according to this disclosure.

[0195] In step S1510, the second STA can receive PPDU from the first STA in one or more of the first or second frequency units within the bandwidth including the first and second frequency units.

[0196] The specific examples of PPDU types and / or formats in the illustrations in Figure 15, particularly the first SIG (e.g., U-SIG), second SIG (e.g., UHR-SIG), and non-legacy STF / LTF fields (e.g., UHR-STF / UHR-LTF) included in the non-legacy preamble, are the same as the explanation for Figure 14, and the redundant explanation is omitted.

[0197] In step S1520, the second STA can process the received PPDU.

[0198] For example, if the second STA has PPDU reception capacity for a wide bandwidth, it can receive PPDUs in the bandwidth including the first and second frequency units, and even if it does not have such capacity, it can detect and receive PPDUs in the first or second frequency unit and process them. Processing of the PPDU may include obtaining information from the SIG field included in the PHY preamble, performing synchronization / AGC / channel estimation based on the STF / LTF, and further obtaining the MAC PDU included in the data field of the PPDU based on that.

[0199] In the examples shown in Figures 14 and 15, the first STA may be AP and the second STA may be non-AP STA, or the first STA may be non-AP STA and the second STA may be AP.

[0200] The broadband PPDUs of this disclosure are distinguished from A-PPDUs (aggregated-PPDUs). An A-PPDU is a format in which multiple PPDUs of different formats are merged, while the broadband PPDUs of this disclosure have one identical format across the entire bandwidth and are characterized in that some fields of the non-legacy preamble contain different information for predetermined units.

[0201] Furthermore, unlike existing wireless LAN systems where the configuration of U-SIG and EHT-SIG changes depending on whether OFDMA or non-OFDMA is used in the MU PPDU, the PPDU for wide bandwidths of this disclosure has a new type of PPDU format in which the PPDU for the entire bandwidth is composed of the same single type, depending on whether OFDMA or non-OFDMA is used in each of the multiple frequency units. In particular, according to this disclosure, when a non-OFDMA multiplex access scheme is applied in each of the first and second frequency units (for example, when transmitting to only one STA on one frequency unit, or when transmitting to multiple STAs on one frequency unit, but multiplexing on the frequency domain is not applied and MU-MIMO (i.e., multiplexing on the spatial domain) is applied), the overall bandwidth including the first and second frequency units corresponds to OFDMA, but the PPDU format itself may be configured as a non-OFDMA type format. This feature applies only to PPDUs for wide bandwidths as described in this disclosure and represents a new solution to support PPDU transmission and reception for wide bandwidths, even when it is not possible to allocate a wide bandwidth to a single non-AP STA for transmission (i.e., an environment where STAs without PPDU reception capacity for wide bandwidths coexist). On the other hand, in existing bandwidth MU PPDUs (e.g., bandwidths of 320 MHz or less), the 320 MHz PPDU is configured by the OFDMA type, even if non-OFDMA transmission is applied to multiple 160 MHz frequency units / channels.

[0202] The following describes specific examples of PPDU types / formats for wide bandwidths related to this disclosure.

[0203] Example 1

[0204] This embodiment relates to a case where the wide bandwidth is 640 MHz, and the multiple frequency units contained within it each correspond to a size of 320 MHz. Specifically, a concrete example of the type / format of a 640 MHz PPDU is described when the first frequency unit corresponds to 320 MHz and the second frequency unit also corresponds to 320 MHz.

[0205] For example, the type of PPDU transmission for a wide bandwidth may be either OFDMA or non-OFDMA. The content structure of the PPDU's U-SIG and non-legacy SIG may differ depending on whether it is OFDMA or non-OFDMA. For example, when transmitting at 640MHz, the overall content structure of the U-SIG and non-legacy SIG may be determined / generated by a structure predefined by either OFDMA or non-OFDMA. Even if non-OFDMA transmission is performed in some frequency units / channels, if the MU PPDU is of OFDMA type, the U-SIG and non-legacy SIG structure within those frequency units / channels may be determined / generated by a structure defined by OFDMA. The boundaries of each field within a single PPDU (e.g., legacy preamble, non-legacy preamble, data field, etc.) across multiple frequency units / channels, and the symbol boundaries within those fields, may be aligned in the time domain, and furthermore, the start and end points of the PPDU may always be the same (i.e., aligned).

[0206] The U-SIG and non-legacy SIG for wide bandwidth PPDUs relating to this disclosure may reuse existing U-SIGs and / or existing EHT-SIGs of existing PPDU formats defined in existing wireless LAN systems (e.g., EHT MU PPDU format), or be configured in a format in which some (sub)fields within the existing U-SIG and / or existing EHT-SIG are modified, excluded, or added.

[0207] The U-SIG for a wide bandwidth PPDU relating to this disclosure can indicate the PPDU type (e.g., OFDMA type or non-OFDMA type) and indicate that the bandwidth (BW) is a wide bandwidth (e.g., 640 MHz or 480 MHz).

[0208] The non-legacy SIG for PPDUs with broad bandwidth as described in this disclosure may include common fields and user-specific fields. Furthermore, the content structure of the non-legacy SIG may vary depending on whether the PPDU type is OFDMA or non-OFDMA.

[0209] The types and number of non-legacy STFs and / or non-legacy LTFs of a PPDU for a wide bandwidth as relating to this disclosure may be the same across the entire bandwidth. The non-legacy LTF sequence may be determined / generated using a sequence defined for a wide bandwidth (e.g., 640 MHz or 480 MHz), or using a sequence defined for 320 MHz or 160 MHz for each 320 MHz or 160 MHz frequency unit / channel, or using a sequence defined for 160 / 80 / 40 / 20 MHz if 160 MHz or more is punctured in a particular 320 MHz or 160 MHz frequency unit / channel.

[0210] The data fields of the PPDU for a wide bandwidth as disclosed herein may use / add a PE (packet extension), and the endpoints of the PPDU may be aligned identically across the entire bandwidth (i.e., across multiple frequency units). The starting points of the PPDU for a wide bandwidth may be aligned identically across the entire bandwidth (i.e., across multiple frequency units).

[0211] When transmitting a 640MHz MU PPDU, the overall MU PPDU may be determined to be of OFDMA type or non-OFDMA type based on the PPDU transmission type of each 320MHz unit.

[0212] If each 320MHz frequency unit / channel is a non-OFDMA transmission, the overall PPDU may be determined and transmitted as a non-OFDMA type.

[0213] For example, a RU corresponding to the primary 320MHz channel (i.e., P320) may be assigned to STA1 for SU transmission, and a RU corresponding to the secondary 320MHz channel (i.e., S320) may be assigned to STA2 for SU transmission.

[0214] For example, a RU corresponding to P320 may be assigned to STA1 for SU transmission, and a RU corresponding to S320 may be assigned to STA2 and STA3 for MU MIMO transmission.

[0215] In the example above, from the perspective of the overall 640 MHz bandwidth, it is OFDMA transmission (i.e., different STAs are multiplexed onto different frequency resources), but within each 320 MHz frequency unit / channel, it may be non-OFDMA transmission. In this case, the PPDU for the wide bandwidth according to this disclosure may be generated by a non-OFDMA type / format.

[0216] Next, if at least one of the 320MHz frequency units / channels is an OFDMA transmission, the entire PPDU may be determined and transmitted as an OFDMA type.

[0217] For example, a RU corresponding to P320 may be assigned to STA1 for SU transmission, a RU corresponding to the lower 160MHz of S320 may be assigned to STA2 for SU transmission, and a RU corresponding to the higher 160MHz of S320 may be assigned to STA3 for SU transmission. This applies when non-OFDMA transmission is performed within P320 and OFDMA transmission is performed within S320.

[0218] In such examples, if OFDMA transmission is applied to one or more of the multiple 320MHz frequency units / channels (for example, in the above example, OFDMA transmission is applied only to S320, but also if OFDMA transmission is applied only to P320, or if OFDMA transmission is applied to both P320 and S320), the PPDU for the wide bandwidth according to this disclosure may be generated by the OFDMA type / format.

[0219] Figures 16 to 18 illustrate examples of PPDU formats for wide bandwidths according to this disclosure.

[0220] Figure 16 shows examples for U-SIG, non-legacy SIG (e.g., UHR-SIG), non-legacy STF (e.g., UHR-STF), and non-legacy LTF (e.g., UHR-LTF) when non-OFDMA transmission is applied to each 320 MHz frequency unit / channel within the 640 MHz bandwidth (i.e., both P320 and S320), and the 640 MHz MU PPDU is set to non-OFDMA type. The examples of this disclosure may also apply when P320 is located at a higher frequency than S320, unlike the examples in Figure 16.

[0221] In this case, non-AP STA assumes a situation where frequency units / channels are pre-assigned to P320 or S320 using methods such as SST. That is, non-AP STA assumes that it can receive on the primary channel as well as receive only on secondary channels that are not the primary channel.

[0222] The U-SIG may include information such as the preamble puncturing pattern and SU / MU-MIMO type. The field values ​​of the U-SIG may include information that is distinguished by 320MHz. The U-SIG can indicate the information of the 320MHz frequency unit / channel in which it is contained. That is, the U-SIG field values ​​are the same within a 320MHz frequency unit / channel, but the U-SIG field values ​​may be different for different 320MHz frequency units / channels. Also, within a single 320MHz frequency unit / channel, the U-SIG field values ​​of multiple 20MHz frequency subunits / subchannels may be the same.

[0223] The common fields of a UHR-SIG can indicate information such as spatial reuse, LTF-related information, LDPC extra symbol segment, padding, and number of users. The field values ​​of the UHR-SIG common fields may include information that is distinguished by 320MHz. The UHR-SIG common fields can indicate information about the 320MHz frequency unit / channel in which the UHR-SIG is contained. That is, the field values ​​of the UHR-SIG common fields are the same within a 320MHz frequency unit / channel, but the field values ​​of the UHR-SIG common fields may be different for different 320MHz frequency units / channels. Also, within a single 320MHz frequency unit / channel, the field values ​​of the UHR-SIG common fields for multiple 20MHz frequency subunits / subchannels may be the same.

[0224] Of the information included in the common fields of the UHR-SIG, the UHR-LTF type, guard interval (GI), and number of LTF symbols may be set to be the same across the entire 640 MHz bandwidth. If the number of LTF symbols required for P320 and S320 differs, the number of LTF symbols may be determined based on the 320 MHz frequency unit / channel that requires the larger number of LTF symbols.

[0225] The common fields in UHR-SIG do not necessarily need to include fields such as RU assignment fields.

[0226] The user-specific field of a UHR-SIG may include a user field, CRC, tail, etc. The field value of the UHR-SIG user-specific field may include information that is distinguished by 320MHz. The UHR-SIG user-specific field may include information provided to the STA assigned to the 320MHz frequency unit / channel in which the UHR-SIG is contained. That is, the field value of the UHR-SIG user-specific field may be the same within a 320MHz frequency unit / channel, but the field value of the UHR-SIG user-specific field may be different for different 320MHz frequency units / channels. Also, within a single 320MHz frequency unit / channel, the field values ​​of the UHR-SIG user-specific field for each of the multiple 20MHz frequency subunits / subchannels may be the same.

[0227] Figures 17 and 18 illustrate examples for U-SIG, non-legacy SIG (e.g., UHR-SIG), non-legacy STF (e.g., UHR-STF), and non-legacy LTF (e.g., UHR-LTF) when the 640MHz MU PPDU is configured as OFDMA type by applying OFDMA transmission to one of several 320MHz frequency units / channels within a 640MHz bandwidth (e.g., P320) and non-OFDMA transmission to the other (e.g., S320). The examples of this disclosure may also apply when P320 is located at a higher frequency than S320, when non-OFDMA is applied to P320 and OFDMA is applied to S320, or when OFDMA is applied to both P320 and S320, contrary to the examples in Figures 17 and 18.

[0228] In this case, the non-AP STA may have a frequency unit / channel pre-assigned to P320 or S320 using a method such as SST, and if SST is not applied, it may switch to the frequency unit / channel to which it was assigned during PPDU reception on the primary channel.

[0229] The U-SIG may include information such as the preamble puncturing pattern and SU / MU-MIMO type. The field values ​​of the U-SIG may include information that is distinguished by 80MHz units (or subchannels or frequency subunits). This may be related to the fact that the preamble puncturing pattern is indicated in 80MHz units. The U-SIG can indicate the information of the 80MHz unit in which it is contained. That is, the U-SIG field values ​​are the same within an 80MHz unit, but the U-SIG field values ​​may be different for different 80MHz units. Also, within a single 80MHz unit, the U-SIG field values ​​for multiple 20MHz frequency subunits / subchannels may be the same.

[0230] Common fields in the UHR-SIG can indicate information such as spatial reuse, LTF-related information, LDPC extra symbol segment, padding, and RU allocation. User-specific fields in the UHR-SIG may include user fields, CRC, tail, etc.

[0231] The UHR-SIG field may be configured across two content channels within the overall bandwidth. For example, as illustrated in Figure 17, information about odd-numbered 20MHz frequency subunits / subchannels from the lower frequency positions of the PPDU in the overall bandwidth is included in content channel 1, and the same field value may be transmitted for all odd-numbered 20MHz frequency subunits / subchannels. Similarly, information about even-numbered 20MHz frequency subunits / subchannels from the lower frequency positions of the PPDU in the overall bandwidth is included in content channel 2, and the same field value may be transmitted for all even-numbered 20MHz frequency subunits / subchannels. In other words, content channels 1 and 2 may be mapped alternately on a 20MHz frequency subunit / subchannel basis. Such a UHR-SIG structure may be applied regardless of whether SST is applied or considered.

[0232] As an addition or alternative, the UHR-SIG field may be configured in two content channels for each of the multiple frequency units within the overall bandwidth. For example, as illustrated in Figure 18, information regarding the odd-numbered 20MHz frequency subunits / subchannels from the lower frequency positions of the P320 PPDU is included in content channel 1, and the same field value may be transmitted for all odd-numbered 20MHz frequency subunits / subchannels. Similarly, information regarding the even-numbered 20MHz frequency subunits / subchannels from the lower frequency positions of the P320 PPDU is included in content channel 2, and the same field value may be transmitted for all even-numbered 20MHz frequency subunits / subchannels. That is, within the first frequency unit, content channels 1 and 2 may be mapped alternately on a 20MHz frequency subunit / subchannel basis. Also, as illustrated in Figure 18, information regarding the odd-numbered 20MHz frequency subunits / subchannels from the lower frequency positions of the S320 PPDU is included in content channel 3, and the same field value may be transmitted for all odd-numbered 20MHz frequency subunits / subchannels. Similarly, information regarding even-numbered 20MHz frequency subunits / subchannels from the lower frequency positions of the PPDU in S320 is included in content channel 4, and the same field values ​​may be transmitted for all even-numbered 20MHz frequency subunits / subchannels. That is, within the second frequency unit, content channels 3 and 4 may be mapped alternately on a 20MHz frequency subunit / subchannel basis. Such a UHR-SIG structure may be applied when SST is applicable / considered. For example, in situations where a non-AP STA is assigned to only one of several frequency units, or to only a specific size (e.g., 20, 40, 80, or 160MHz) frequency subunit, a UHR-SIG that is distinguished by frequency unit or frequency subunit may be configured.

[0233] Example 2

[0234] This embodiment relates to a case where the wide bandwidth is 480 MHz, and the multiple frequency units contained within it correspond to sizes of 320 MHz and 160 MHz, respectively. Specifically, a concrete example of the type / format of a 480 MHz PPDU is described when the first frequency unit corresponds to 320 MHz and the second frequency unit corresponds to 160 MHz.

[0235] 480MHz may not be defined as a partial subchannel puncturing of 640MHz, but rather as a new single bandwidth. In this case, 480MHz may be a combination of one 160MHz frequency unit / channel within P320 and S320, or a combination of P160 and S320. The examples in Figures 19 to 21 illustrate the case of P320 and S160, but the same examples may also apply to the case of P160 and S320.

[0236] The format of the 480MHz PPDU may be the same as the case in the 640MHz PPDU format of Example 1 where S320 is replaced with S160. Therefore, the same principle as the examples described in Example 1 may be applied, and specific examples are as follows.

[0237] When transmitting a 480MHz MU PPDU, the overall MU PPDU may be determined to be of OFDMA type or non-OFDMA type based on the PPDU transmission type in 320MHz units and the PPDU transmission type in 160MHz units.

[0238] If both the 320MHz and 160MHz frequency units / channels are non-OFDMA transmissions, the overall PPDU may be determined and transmitted as a non-OFDMA type.

[0239] For example, a RU corresponding to the primary 320MHz channel (i.e., P320) may be assigned to STA1 for SU transmission, and a RU corresponding to the secondary 160MHz channel (i.e., S160) may be assigned to STA2 for SU transmission.

[0240] For example, a RU corresponding to P320 may be assigned to STA1 for SU transmission, and a RU corresponding to S160 may be assigned to STA2 and STA3 for MU MIMO transmission.

[0241] In the example above, the transmission is OFDMA in terms of the overall 480MHz bandwidth (i.e., different STAs are multiplexed onto different frequency resources), but within the respective frequency units / channels of 320MHz and 160MHz, it may be non-OFDMA transmission. In this case, the PPDU for the wide bandwidth according to this disclosure may be generated by a non-OFDMA type / format.

[0242] Next, if OFDMA transmission is performed on at least one of the 320MHz and 160MHz frequency units / channels, the entire PPDU may be determined and transmitted as OFDMA type.

[0243] For example, RUs corresponding to the lower 160MHz range in P320 may be assigned to STA1 for SU transmission, while RUs corresponding to the higher 160MHz range in P320 may be assigned to STA2 for SU transmission. RUs corresponding to S160 may be assigned to STA3 for SU transmission. This applies when OFDMA transmission is performed within P320 and non-OFDMA transmission is performed within S160.

[0244] In such examples, if OFDMA transmission is applied to one or more of several frequency units / channels of different sizes (for example, in the above example, OFDMA transmission is applied only to P320, or only to S160, or to both P320 and S160), the PPDU for wide bandwidth according to this disclosure may be generated by an OFDMA type / format.

[0245] Figures 19 to 21 illustrate examples of PPDU formats for wide bandwidths according to this disclosure.

[0246] Figure 19 shows examples for U-SIG, non-legacy SIG (e.g., UHR-SIG), non-legacy STF (e.g., UHR-STF), and non-legacy LTF (e.g., UHR-LTF) when non-OFDMA transmission is applied to both 320MHz and 160MHz frequency units / channels within a 480MHz bandwidth (i.e., in both P320 and S160), and the 480MHz MU PPDU is set to non-OFDMA type. The examples of this disclosure may also apply when P320 is located at a higher frequency than S160, unlike the examples in Figure 19.

[0247] In this case, non-AP STA assumes a situation where frequency units / channels are pre-assigned to P320 or S160 using a method such as SST. That is, non-AP STA assumes that it can receive on the primary channel as well as on secondary channels that are not the primary channel.

[0248] The U-SIG may include information such as the preamble puncturing pattern and SU / MU-MIMO type. The field values ​​of the U-SIG may include information distinguished by 320MHz and 160MHz. The U-SIG can indicate information for the 320MHz or 160MHz frequency unit / channel in which it is contained. That is, the U-SIG field values ​​may be the same within a 320MHz frequency unit / channel and the same within a 160MHz frequency unit / channel, but the U-SIG field values ​​may be different for 320MHz and 160MHz frequency units / channels. Also, within a single 320MHz or single 160MHz frequency unit / channel, the U-SIG field values ​​for each of the multiple 20MHz frequency subunits / subchannels may be the same.

[0249] The common fields of a UHR-SIG can indicate information such as spatial reuse, LTF-related information, LDPC extra symbol segment, padding, and number of users. The field values ​​of the UHR-SIG common fields may include information that is distinct for 320MHz and 160MHz. The UHR-SIG common fields can indicate information for the 320MHz or 160MHz frequency unit / channel in which the UHR-SIG is contained. That is, the field values ​​of the UHR-SIG common fields are the same within a 320MHz frequency unit / channel and the same within a 160MHz frequency unit / channel, but the field values ​​of the UHR-SIG common fields may be different for 320MHz and 160MHz frequency units / channels. Also, within a single 320MHz or 160MHz frequency unit / channel, the field values ​​of the UHR-SIG common fields for multiple 20MHz frequency subunits / subchannels may be the same.

[0250] Of the information included in the common fields of the UHR-SIG, the UHR-LTF type, guard interval (GI), and number of LTF symbols may be set to be the same across the entire 480MHz bandwidth. If the number of LTF symbols required for P320 and S160 differs, the number of LTF symbols may be determined based on the 320MHz or 160MHz frequency unit / channel that requires the larger number of LTF symbols.

[0251] The common fields in UHR-SIG do not necessarily need to include fields such as RU assignment fields.

[0252] The user-specific field of a UHR-SIG may include a user field, CRC, tail, etc. The field value of the UHR-SIG user-specific field may include information that is distinguished separately for 320MHz or 160MHz. The UHR-SIG user-specific field may include information provided to the STA assigned to the 320MHz or 160MHz frequency unit / channel in which the UHR-SIG is contained. That is, the field value of the UHR-SIG user-specific field may be the same within a 320MHz frequency unit / channel and the field value of the UHR-SIG user-specific field may be the same within a 160MHz frequency unit / channel, but the field values ​​of the UHR-SIG user-specific field may be different for 320MHz and 160MHz frequency units / channels. Also, within a single 320MHz or single 160MHz frequency unit / channel, the field values ​​of the UHR-SIG user-specific field for each of the multiple 20MHz frequency subunits / subchannels may be the same.

[0253] Figures 20 and 21 illustrate examples for U-SIG, non-legacy SIG (e.g., UHR-SIG), non-legacy STF (e.g., UHR-STF), and non-legacy LTF (e.g., UHR-LTF) when the 480MHz MU PPDU is configured as OFDMA type by applying OFDMA transmission to one of several 320MHz frequency units / channels within a 480MHz bandwidth (e.g., P320) and non-OFDMA transmission to the other (e.g., S160). The examples of this disclosure may also apply when P320 is located at a higher frequency than S160, and non-OFDMA is applied to P320 and OFDMA to S160, or when OFDMA is applied to both P320 and S160, unlike the examples in Figures 20 and 21.

[0254] In this case, the non-AP STA may have a frequency unit / channel pre-assigned to P320 or S160 using a method such as SST, and if SST is not applied, it may switch to the frequency unit / channel to which it is assigned during PPDU reception on the primary channel.

[0255] The U-SIG may include information such as the preamble puncturing pattern and SU / MU-MIMO type. The field values ​​of the U-SIG may include information that is distinguished by 80MHz units (or subchannels or frequency subunits). This may be related to the fact that the preamble puncturing pattern is indicated in 80MHz units. The U-SIG can indicate the information of the 80MHz unit in which it is contained. That is, the U-SIG field values ​​are the same within an 80MHz unit, but the U-SIG field values ​​may be different for different 80MHz units. Also, within a single 80MHz unit, the U-SIG field values ​​for multiple 20MHz frequency subunits / subchannels may be the same.

[0256] Common fields in the UHR-SIG can indicate information such as spatial reuse, LTF-related information, LDPC extra symbol segment, padding, and RU allocation. User-specific fields in the UHR-SIG may include user fields, CRC, tail, etc.

[0257] The UHR-SIG field may be configured across two content channels within the overall bandwidth. For example, as illustrated in Figure 20, information regarding odd-numbered 20MHz frequency subunits / subchannels from the lower frequency positions of the PPDU in the overall bandwidth is included in content channel 1, and the same field value may be transmitted for all odd-numbered 20MHz frequency subunits / subchannels. Similarly, information regarding even-numbered 20MHz frequency subunits / subchannels from the lower frequency positions of the PPDU in the overall bandwidth is included in content channel 2, and the same field value may be transmitted for all even-numbered 20MHz frequency subunits / subchannels. In other words, content channels 1 and 2 may be mapped alternately on a 20MHz frequency subunit / subchannel basis. Such a UHR-SIG structure may be applied regardless of whether SST is applied or considered.

[0258] As an addition or alternative, the UHR-SIG field may be configured in two content channels for each of the multiple frequency units within the overall bandwidth. For example, as illustrated in Figure 21, information regarding the odd-numbered 20MHz frequency subunits / subchannels from the lower frequency position of the P320 PPDU is included in content channel 1, and the same field value may be transmitted for all odd-numbered 20MHz frequency subunits / subchannels. Similarly, information regarding the even-numbered 20MHz frequency subunits / subchannels from the lower frequency position of the P320 PPDU is included in content channel 2, and the same field value may be transmitted for all even-numbered 20MHz frequency subunits / subchannels. That is, within the first frequency unit, content channels 1 and 2 may be mapped alternately on a 20MHz frequency subunit / subchannel basis. Also, as illustrated in Figure 21, information regarding the odd-numbered 20MHz frequency subunits / subchannels from the lower frequency position of the S160 PPDU is included in content channel 3, and the same field value may be transmitted for all odd-numbered 20MHz frequency subunits / subchannels. Similarly, information regarding even-numbered 20MHz frequency subunits / subchannels from the lower frequency positions of the PPDU in S160 is included in content channel 4, and the same field values ​​may be transmitted for all even-numbered 20MHz frequency subunits / subchannels. That is, within the second frequency unit, content channels 3 and 4 may be mapped alternately on a 20MHz frequency subunit / subchannel basis. Such a UHR-SIG structure may be applied when SST is applicable / considered. For example, in situations where a non-AP STA is assigned to only one of several frequency units, or to only a specific size (e.g., 20, 40, 80, or 160MHz) frequency subunit, a UHR-SIG that is distinguished by frequency unit or frequency subunit may be configured.

[0259] In the examples described above, even if the PPDU type for a wide bandwidth is non-OFDMA, and OFDMA transmission is not applied within a frequency unit, MU-MIMO may be applied and transmissions may be made to multiple STAs. In this case, in order to provide UHR-SIG information to multiple STAs, the UHR-SIG consists of content channel 1 and content channel 2, and within the frequency band or the overall bandwidth, content channel 1 may be mapped to odd-numbered 20MHz frequency subunits / subchannels, and content channel 2 may be mapped to even-numbered 20MHz frequency subunits / subchannels.

[0260] The embodiments described above are combinations of the components and features of the present disclosure in a predetermined form. Each component or feature should be considered optional unless otherwise explicitly mentioned. Each component or feature may be implemented in a form that does not combine with other components or features. It is also possible to combine some components and / or features to constitute embodiments of the present disclosure. The order of operations described in embodiments of the present disclosure may be changed. Some components or features of one embodiment may be included in other embodiments, or replaced by corresponding components or features of other embodiments. It is clear that claims that do not have an explicit reference relationship in the claims may be combined to constitute embodiments, or may be included as new claims by amendment after filing.

[0261] It will be obvious to those skilled in the art that this disclosure can be embodied in other specific forms, provided that the essential features of this disclosure are not deviated from. Therefore, the above-mentioned detailed description should not be constrained in any way and should be considered illustrative. The scope of this disclosure should be determined by a reasonable interpretation of the attached claims, and any modifications within the equivalent scope of this disclosure are included within the scope of this disclosure.

[0262] The scope of this disclosure includes software or machine-executable instructions (e.g., operating systems, applications, firmware, programs, etc.) that cause an apparatus or computer to perform operations according to the methods of various embodiments, and non-transitory computer-readable medium on which such software or instructions are stored and executable on the apparatus or computer. Instructions available for programming a processing system that performs the features described in this disclosure may be stored on / in a storage medium or computer-readable storage medium, and the features described in this disclosure may be embodied using a computer program product including such storage medium. The storage medium may include, but is not limited to, high-speed random-access memory such as DRAM, SRAM, DDR RAM, or other random-access solid-state memory devices, and may include non-volatile memory such as one or more magnetic disk storage devices, optical disk storage devices, flash memory devices, or other non-volatile solid-state storage devices. Memory optionally includes one or more storage devices located remotely from the processor. Memory, or alternatively, non-volatile memory devices within memory, includes non-transitory computer-readable storage medium. The features described in this disclosure may be stored on any one of the machine-readable media and integrated into software and / or firmware that can control the hardware of the processing system and cause the processing system to interact with other mechanisms that utilize the results relating to the embodiments of this disclosure. Such software or firmware may include, but is not limited to, application code, device drivers, operating systems and execution environments / containers. [Industrial applicability]

[0263] Although the method proposed in this disclosure has been primarily described in terms of its application to IEEE 802.11-based systems, it can be applied to a variety of other wireless LAN or wireless communication systems.

Claims

1. Based on the multiple access type in the first frequency unit and the second frequency unit, the first STA (station) generates a first-type or second-type PPDU (physical layer protocol data unit), The step includes the step of the first STA transmitting the PPDU to at least one second STA on a bandwidth including the first frequency unit and the second frequency unit, Based on the fact that the multiple access type for the first frequency unit is the first type and the multiple access type for the second frequency unit is the first type, the first type PPDU is generated. A method for generating a second type PPDU based on the fact that at least one of the multiple access types for the first frequency unit or the multiple access types for the second frequency unit is of the second type.

2. The U-SIG (universal-signal) field included in the non-legacy preamble of the first type PPDU is, Information distinguished in the first frequency unit and the second frequency unit, The method according to claim 1, further comprising the same information in each of a plurality of 20 MHz frequency subunits within the first frequency unit or the second frequency unit.

3. The non-legacy SIG field included in the non-legacy preamble of the first type PPDU is, Information distinguished in the first frequency unit and the second frequency unit, The method according to claim 1, further comprising the same information in each of at least one frequency subunit of a predetermined size within the first frequency unit or the second frequency unit.

4. The U-SIG field included in the non-legacy preamble of the second type of PPDU is, Information distinguished in each of the multiple 80 MHz frequency subunits within the aforementioned bandwidth, The method according to claim 1, further comprising the same information in each of the plurality of 20 MHz frequency subunits, each of the plurality of 80 MHz frequency subunits.

5. The method according to claim 1, wherein the non-legacy SIG field included in the non-legacy preamble of the second type of PPDU includes a first content in an odd-numbered frequency subunit and a second content in an even-numbered frequency subunit among a plurality of 20 MHz frequency subunits within the bandwidth.

6. The non-legacy SIG field included in the non-legacy preamble of the second type of PPDU is, The first content in the odd-numbered frequency subunits among the multiple 20 MHz frequency subunits within the first frequency unit, and the second content in the even-numbered frequency subunits, The method according to claim 1, further comprising a third content in the odd-numbered frequency subunits and a fourth content in the even-numbered frequency subunits among the plurality of 20 MHz frequency subunits within the second frequency unit.

7. The method according to claim 6, wherein SST (subchannel selective transmission) is instructed for one of the first frequency unit or the second frequency unit.

8. The method according to claim 1, wherein the U-SIG field included in the non-legacy preamble of the PPDU includes at least one of information indicating the type of the PPDU or information relating to the size of the bandwidth.

9. At least one of the non-legacy LTF (long training field) fields or non-legacy STF (short training field) fields included in the non-legacy preamble of the PPDU is: A sequence of length corresponding to the size of the aforementioned bandwidth, A sequence of length corresponding to the size of the first frequency unit, A sequence of length corresponding to the size of the second frequency unit, or The method according to claim 1, based on at least one sequence of lengths corresponding to the size of the remaining frequency subunits excluding the punctured portion of the frequency subunit, based on the puncture of a portion of a frequency subunit in at least one of the first frequency unit or the second frequency unit.

10. The number of symbols in the LTF field included in the non-legacy preamble of the PPDU is the same throughout the entire bandwidth. The method according to claim 1, wherein the number of symbols in the LTF field is the maximum value of the number of symbols in the LTF field required in the first frequency unit and the number of symbols in the LTF field required in the second frequency unit.

11. The method according to claim 1, wherein the start and end points of the PPDU are the same throughout the entire bandwidth.

12. The first type mentioned above corresponds to non-OFDMA (orthogonal frequency division multiple access), The method according to claim 1, wherein the second type corresponds to OFDMA.

13. Based on the fact that the bandwidth size is 640 MHz, the size of the first frequency unit is 320 MHz, and the size of the second frequency unit is 320 MHz. The method according to claim 1, wherein, based on the size of the bandwidth being 480 MHz, the size of the first frequency unit is 320 MHz and the size of the second frequency unit is 160 MHz, or the size of the first frequency unit is 160 MHz and the size of the second frequency unit is 320 MHz.

14. The method according to claim 1, wherein the first frequency unit corresponds to a primary channel and the second frequency unit corresponds to a secondary channel.

15. At least one transceiver and, The system comprises at least one processor connected to the at least one transceiver, The aforementioned at least one processor is Based on the multiple access type in the first frequency unit and the second frequency unit, a first-type or second-type PPDU (physical layer protocol data unit) is generated. The PPDU is configured to be transmitted to at least one second STA (station) via at least one transceiver on a bandwidth including the first frequency unit and the second frequency unit, Based on the fact that the multiple access type for the first frequency unit is the first type and the multiple access type for the second frequency unit is the first type, the first type PPDU is generated. A first STA is generated based on the fact that at least one of the multiple access types for the first frequency unit or the multiple access types for the second frequency unit is of the second type.

16. In a bandwidth including the first frequency unit and the second frequency unit, the second STA (station) receives a PPDU (physical layer protocol data unit) from the first STA in at least one of the first frequency unit or the second frequency unit, The step includes the step of the second STA processing the received PPDU, Based on the multiplex access type in the first frequency unit and the second frequency unit, the PPDU has a format according to the first type or the second type. Based on the fact that the multiple access type for the first frequency unit is the first type and the multiple access type for the second frequency unit is the first type, the first type PPDU is generated. A method for generating a second type PPDU based on the fact that at least one of the multiple access types for the first frequency unit or the multiple access types for the second frequency unit is of the second type.

17. At least one transceiver and, The system comprises at least one processor connected to the at least one transceiver, The aforementioned at least one processor is In the bandwidth including the first frequency unit and the second frequency unit, a PPDU (physical layer protocol data unit) is received from the first STA (station) via the at least one transceiver in at least one of the first frequency unit or the second frequency unit. It is configured to process the received PPDU, Based on the multiplex access type in the first frequency unit and the second frequency unit, the PPDU has a format according to the first type or the second type. Based on the fact that the multiple access type for the first frequency unit is the first type and the multiple access type for the second frequency unit is the first type, the first type PPDU is generated. A second STA is generated based on the fact that at least one of the multiple access types for the first frequency unit or the multiple access types for the second frequency unit is of the second type.

18. A processing unit configured to control a station (STA) in a WLAN (wireless local area network) system, wherein the processing unit is: At least one processor, A processing unit comprising: at least one computer memory operably connected to the at least one processor, and storing instructions for performing the method according to any one of claims 1 to 14 based on being executed by the at least one processor.

19. A non-temporary computer-readable medium for storing at least one instruction, A computer-readable medium wherein the at least one instruction is executed by at least one processor to control a station (STA) device in a wireless local area network (WLAN) system to perform the method according to any one of claims 1 to 14.

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