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

Abstract

A distributed resource unit tone plan-based transmission or reception method and apparatus in a wireless WLAN system are disclosed. A method performed by a first STA in a wireless local area network (WLAN) system according to an embodiment of the present disclosure comprises the steps of: generating a PPDU including a plurality of symbol groups, in which the plurality of symbol groups are mapped to at least one DRU; and transmitting the PPDU over the bandwidth to the at least one second STA, in which the plurality of symbol groups include a first symbol group and a second symbol group subsequent to the first symbol group, at least one first pilot tone corresponding to a position of the first symbol group is used in the first symbol group among a plurality of pilot tones of a predefined RU related to the bandwidth, and at least one second pilot tone corresponding to a position of the second symbol group is used in the second symbol group among the plurality of pilot tones of the predefined RU related to the bandwidth. And an index of each of a plurality of second pilot tones respectively used in the plurality of symbols included in the second symbol group may be based on a cyclic shift value applied to each of the plurality of symbols in the second symbol group.

Description

Technical Field

[0001] This disclosure relates to a method and apparatus for transmitting or receiving data in a wireless local area network (WLAN) system based on a distributed resource unit tone scheme. Background Technology

[0002] New technologies have been introduced to Wireless LANs (WLANs) to improve transmission rates, increase bandwidth, improve reliability, reduce errors, and reduce latency. Within WLAN technologies, the IEEE 802.11 series of standards can be referred to as Wi-Fi. For example, recent technologies introduced to WLAN include enhancements to the Very High Throughput (VHT) of the 802.11ac standard and enhancements to the High Efficiency (HE) of the IEEE 802.11ax standard.

[0003] To provide a more robust wireless communication environment, enhancement technologies for EHT (Extreme High Throughput) are being discussed. For example, technologies for supporting multi-access point (AP) coordination and multiple-input multiple-output (MIMO) to increase bandwidth, effectively utilize multiple bands, and increase spatial flow are being investigated. In particular, various technologies are being explored to support low-latency or real-time services. Furthermore, new technologies to support Ultra-High Reliability (UHR) through improvements or extensions to EHT technologies are being discussed. Summary of the Invention

[0004] Technical issues

[0005] The technical problem of this disclosure is to provide a method and apparatus for transmitting or receiving based on a distributed resource unit tone plan in a WLAN system.

[0006] The technical problem of this disclosure is to provide a method and apparatus for shifting pilot tones for each symbol in a wireless LAN system.

[0007] The technical objectives achieved through this disclosure are not limited to those described above, and those skilled in the art will clearly understand from the following description other technical objectives not described herein.

[0008] Technical solution

[0009] According to one embodiment of this disclosure, a method performed by a first station (STA) in a wireless local area network (WLAN) system may include: generating a physical layer protocol data unit (PPDU) comprising a plurality of symbol groups, the plurality of symbol groups being mapped to at least one distributed resource unit (DRU); and transmitting the PPDU to at least one second STA in a bandwidth, wherein the plurality of symbol groups may include a first symbol group and a second symbol group following the first symbol group, and at least one first pilot tone corresponding to a position of the first symbol group among a plurality of pilot tones of a predefined resource unit associated with the bandwidth may be used in the first symbol group, and the index of each of a plurality of second pilot tones used in each of the plurality of symbols included in the second symbol group may be based on a cyclic shift value applied to each of the plurality of symbols included in the second symbol group.

[0010] According to another embodiment of this disclosure, a method performed by a second station (STA) in a wireless LAN system may include: receiving, via bandwidth, a physical layer protocol data unit (PPDU) comprising a plurality of symbol groups, the plurality of symbol groups being mapped to at least one distributed resource unit (DRU); and decoding the PPDU, wherein the plurality of symbol groups may include a first symbol group and a second symbol group following the first symbol group, and at least one first pilot tone corresponding to a position of the first symbol group among a plurality of pilot tones of a predefined resource unit associated with bandwidth may be used in the first symbol group, and the index of each of a plurality of second pilot tones used in each of the plurality of symbols included in the second symbol group may be based on a cyclic shift value applied to each of the plurality of symbols included in the second symbol group.

[0011] Beneficial effects

[0012] According to this disclosure, a method and apparatus for transmitting or receiving based on a distributed resource unit tone scheme in a wireless LAN system can be provided.

[0013] According to this disclosure, a method and apparatus for symbol-by-symbol shifting of pilot tones in a wireless LAN system can be provided.

[0014] According to this disclosure, in a DRU that is sensitive to carrier frequency offset (CFO), improved residual CFO tracking can improve DRU transport-related coverage / throughput.

[0015] The effects achievable by this disclosure are not limited to those described above, and those skilled in the art can clearly understand other effects not described herein through the following description. Attached Figure Description

[0016] The accompanying drawings, included as part of the detailed description for understanding this disclosure, provide embodiments of the disclosure and describe the technical features of the disclosure through detailed description.

[0017] Figure 1 The figure shows a block configuration diagram of a wireless communication device according to an embodiment of the present disclosure.

[0018] Figure 2 This is a diagram illustrating an exemplary structure of a WLAN system to which this disclosure can be applied.

[0019] Figure 3 It is a diagram used to describe the link setup process to which this disclosure can be applied.

[0020] Figure 4 It is a diagram used to describe the retreat process to which this disclosure can be applied.

[0021] Figure 5 This is a diagram used to describe the CSMA / CA-based frame transmission operation to which this disclosure can be applied.

[0022] Figure 6 This is a diagram illustrating an example of a frame structure that can be used in a WLAN system to which this disclosure may be applied.

[0023] Figure 7 This is a diagram illustrating an example of a PPDU that can be applied in the IEEE 802.11 standard of this disclosure.

[0024] Figures 8 to 10 This is a diagram illustrating an example of a resource unit for a WLAN system to which the present disclosure may be applied.

[0025] Figure 11 This is a diagram illustrating an example of a DRU that can be applied using the present disclosure.

[0026] Figure 12 This is a diagram illustrating an example of a PPDU receiving method based on a DRU tone scheme for a first STA according to this disclosure.

[0027] Figure 13 This is a diagram illustrating an example of a PPDU transmission method based on a DRU tone scheme for a second STA according to this disclosure.

[0028] Figure 14 This is a diagram illustrating the PPDU transmission and reception process between a transmitting STA and a receiving STA according to an example of this disclosure. Detailed Implementation

[0029] In the following, embodiments according to the present disclosure will be described in detail with reference to the accompanying drawings. The detailed description disclosed with reference to the drawings is intended to describe exemplary embodiments of the present disclosure and not to represent the only embodiments in which the present disclosure may be practiced. The following detailed description includes specific details to provide a complete understanding of the present disclosure. However, those skilled in the art will recognize that the present disclosure may be practiced without these specific details.

[0030] In some cases, known structures and devices may be omitted, or they may be shown in block diagram form based on the core functions of each structure and device in order to prevent ambiguity of the concepts in this disclosure.

[0031] In this disclosure, when an element is referred to as “connected,” “combined,” or “linked” to another element, it can include both indirect and direct connections where another element exists therebetween. Furthermore, in this disclosure, the terms “comprising” or “having” specify the presence of the mentioned features, steps, operations, components, and / or elements, but do not exclude the presence or addition of one or more other features, stages, operations, components, elements, and / or groups thereof.

[0032] In this invention, terms such as "first" and "second" are used only to distinguish one element from another and are not used to limit the elements. Unless otherwise stated, they do not limit the order or importance of the elements. Therefore, within the scope of this disclosure, a first element in one embodiment may be referred to as a second element in another embodiment, and similarly, a second element in one embodiment may be referred to as a first element in another embodiment.

[0033] The terminology used in this disclosure is for the purpose of describing particular embodiments and not for limiting the claims. As used in the description of the embodiments and the appended claims, the singular forms are intended to include the plural forms unless the context clearly indicates otherwise. The term “and / or” as used in this disclosure may refer to one of the associated enumerations, or is intended to refer to and include any and all possible combinations of two or more of them. Furthermore, unless otherwise stated, the “ / ” between words in this disclosure has the same meaning as “and / or”.

[0034] The examples disclosed herein can be applied to various wireless communication systems. For example, the examples disclosed herein can be applied to wireless LAN systems. For example, the examples disclosed herein can be applied to wireless LANs based on the IEEE 802.11a / g / n / ac / ax standards. Furthermore, the examples disclosed herein can be applied to wireless LANs based on the newly proposed IEEE 802.11be (or EHT) standard. The examples disclosed herein can be applied to wireless LANs based on the IEEE 802.11be version 2 standard, corresponding to the additional enhancements of the IEEE 802.11be version 1 standard. Additionally, the examples disclosed herein can be applied to next-generation standards-based wireless LANs following IEEE 802.11be. Furthermore, the examples disclosed herein can be applied to cellular wireless communication systems. For example, it can be applied to cellular wireless communication systems based on 3GPP standards using Long Term Evolution (LTE) technology and 5G New Radio (NR) technology.

[0035] The technical features that can be applied to examples of this disclosure will be described below.

[0036] Figure 1 The figure shows a block diagram of a wireless communication device according to an embodiment of the present disclosure.

[0037] Figure 1 The first device 100 and the second device 200 illustrated in the diagram can be replaced by various terms, such as terminal, wireless device, wireless transceiver unit (WTRU), user equipment (UE), mobile station (MS), user terminal (UT), mobile subscriber station (MSS), mobile subscriber unit (MSU), subscriber station (SS), advanced mobile station (AMS), wireless terminal (WT), or simple user, etc. Furthermore, the first device 100 and the second device 200 can include access point (AP), base station (BS), fixed station, node B, base transceiver system (BTS), and network. It can be replaced by various terms such as artificial intelligence (AI) system, roadside unit (RSU), repeater, router, relay, and gateway.

[0038] Figure 1 The devices 100 and 200 shown in the diagram can be referred to as stations (STAs). For example, Figure 1The devices 100 and 200 illustrated in the figure 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 perform an access point (AP) role or a non-AP role. That is, in this disclosure, STA 110 and 200 can perform AP and / or non-AP functions. When STA 110 and 200 perform AP functions, they can be simply referred to as AP, and when STA 110 and 200 perform non-AP functions, they can be simply referred to as STA. In addition, in this disclosure, AP can also be referred to as APSTA.

[0039] refer to Figure 1 The first device 100 and the second device 200 can transmit and receive radio signals via various wireless LAN technologies (e.g., the IEEE 802.11 series). The first device 100 and the second device 200 may include interfaces for the Media Access Control (MAC) layer and Physical Layer (PHY) conforming to the IEEE 802.11 standard.

[0040] Furthermore, the first device 100 and the second device 200 can additionally support various communication standards (e.g., 3GPP LTE series, 5G NR series standards, etc.) besides wireless LAN technology. Additionally, the devices disclosed herein can be implemented in various devices, such as mobile phones, vehicles, personal computers, augmented reality (AR) devices, virtual reality (VR) devices, etc. Furthermore, 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), IoT (Internet of Things), etc.

[0041] The first device 100 may include one or more processors 102 and one or more memories 104, and may additionally include one or more transceivers 106 and / or one or more antennas 108. The processor 102 may control the memory 104 and / or the transceiver 106 and may be configured to implement the descriptions, functions, processes, proposals, methods, and / or operation flowcharts disclosed herein. For example, the processor 102 may transmit a wireless signal including the first information / signal via the transceiver 106 after generating a first information / signal by processing information in the memory 104. Additionally, the processor 102 may receive a wireless signal including a second information / signal via the transceiver 106, and then store information obtained through signal processing of the second information / signal in the memory 104. The memory 104 may be connected to the processor 102 and may store various information related to the operation of the processor 102. For example, the memory 104 may store software code including instructions for performing all or part of the processes controlled by the processor 102 or for performing the descriptions, functions, processes, proposals, methods, and / or operation flowcharts disclosed herein. Here, processor 102 and memory 104 may be part of a communication modem / circuit / chip designed to implement wireless LAN technologies (e.g., LTE 802.11 series). Transceiver 106 may be connected to processor 102 and may transmit and / or receive wireless signals via one or more antennas 108. Transceiver 106 may include a transmitter and / or a receiver. Transceiver 106 may be used with an RF (radio frequency) unit. In this disclosure, "device" may refer to a communication modem / circuit / chip.

[0042] The second device 200 may include one or more processors 202 and one or more memories 204, and may additionally include one or more transceivers 206 and / or one or more antennas 208. The processor 202 may control the memory 204 and / or the transceiver 206 and may be configured to implement the descriptions, functions, processes, proposals, methods, and / or operation flowcharts disclosed in this disclosure. For example, the processor 202 may generate third information / signals by processing information in the memory 204, and then transmit a wireless signal including the third information / signals via the transceiver 206. Additionally, the processor 202 may receive wireless signals including fourth information / signals via the transceiver 206, and then store information obtained through signal processing of the fourth information / signals in the memory 204. The memory 204 may be connected to the processor 202 and may store various information related to the operation of the processor 202. For example, the memory 204 may store software code including instructions for performing all or part of the processes controlled by the processor 202 or for performing the descriptions, functions, processes, proposals, methods, and / or operation flowcharts disclosed in this disclosure. Here, processor 202 and memory 204 may be part of a communication modem / circuit / chip designed to implement wireless LAN technologies (e.g., IEEE 802.11 series). Transceiver 206 may be connected to processor 202 and may transmit and / or receive wireless signals via one or more antennas 208. Transceiver 206 may include a transmitter and / or a receiver. Transceiver 206 may be used with an RF unit. In this disclosure, "device" may refer to a communication modem / circuit / chip.

[0043] The hardware components of devices 100 and 200 will be described in more detail below. However, they are not limited thereto, but one or more protocol layers may be implemented by one or more processors 102 and 202. For example, one or more processors 102 and 202 may implement one or more layers (e.g., functional layers such as PHY and MAC). One or more processors 102 and 202 may generate one or more PDUs (Protocol Data Units) and / or one or more SDUs (Service Data Units) according to the descriptions, functions, processes, proposals, methods, and / or operation flowcharts disclosed in this disclosure. One or more processors 102 and 202 may generate messages, control information, data, or information according to the descriptions, functions, processes, proposals, methods, and / or operation flowcharts disclosed in this disclosure. One or more processors 102 and 202 may generate signals (e.g., baseband signals) including PDUs, SDUs, messages, control information, data, or information according to the functions, processes, proposals, and / or methods disclosed in this disclosure to provide them to one or more transceivers 106 and 206. One or more processors 102, 202 may receive signals (e.g., baseband signals) from one or more transceivers 106, 206 and obtain PDUs, SDUs, messages, control information, data, or information in accordance with the descriptions, functions, processes, proposals, methods, and / or operation flowcharts disclosed in this disclosure.

[0044] One or more processors 102, 202 may be referred to as controllers, microcontrollers, microprocessors, or microcomputers. One or more processors 102, 202 may be implemented by hardware, firmware, software, or a combination thereof. In examples, 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, processes, proposals, methods, and / or operation flowcharts included in this disclosure may be implemented using firmware or software, and the firmware or software may be implemented to include modules, processes, functions, etc. Firmware or software configured to execute the descriptions, functions, processes, proposals, methods, and / or operation flowcharts included in this disclosure may be included in one or more processors 102, 202 or may be stored in one or more memories 104, 204 and driven by one or more processors 102, 202. The descriptions, functions, processes, proposals, methods, and / or operation flowcharts included in this invention may be implemented by firmware or software in the form of code, commands, and / or command sets.

[0045] One or more memories 104, 204 may be connected to one or more processors 102, 202 and are capable of storing data, signals, messages, information, programs, code, instructions, and / or commands in various forms. One or more memories 104, 204 may be configured with ROM, RAM, EPROM, flash memory, hard disk drive, registers, cache memory, computer-readable storage media, and / or combinations thereof. One or more memories 104, 204 may be located internally and / or externally to one or more processors 102, 202. Furthermore, one or more memories 104, 204 may be connected to one or more processors 102, 202 via various technologies such as wired or wireless connections.

[0046] One or more transceivers 106, 206 can transmit user data, control information, wireless signals / channels, etc., mentioned in the methods and / or operation flowcharts of this disclosure to one or more other devices. One or more transceivers 106, 206 can receive user data, control information, wireless signals / channels, etc., mentioned in the descriptions, functions, processes, proposals, methods, and / or operation flowcharts included in this disclosure from one or more other devices. For example, one or more transceivers 106, 206 can be connected to one or more processors 102, 202 and can transmit and receive wireless signals. For example, one or more processors 102, 202 can control one or more transceivers 106, 206 to transmit user data, control information, or wireless signals to one or more other devices. Furthermore, one or more processors 102, 202 can control one or more transceivers 106, 206 to receive user data, control information, or wireless 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 the one or more transceivers 106, 206 may be configured to transmit and receive user data, control information, wireless signals / channels, etc., mentioned in the descriptions, functions, processes, proposals, methods, and / or operation flowcharts included in this disclosure via one or more antennas 108, 208. In this invention, one or more antennas may be multiple physical antennas or multiple logical antennas (e.g., antenna ports). The one or more transceivers 106, 206 may process the received wireless signals / channels, etc., by converting them from RF band signals to baseband signals using one or more processors 102, 202. The one or more transceivers 106, 206 may convert the user data, control information, wireless signals / channels, etc., processed by using one or more processors 102, 202 from baseband signals to RF band signals. Therefore, the one or more transceivers 106, 206 may include (analog) oscillators and / or filters.

[0047] For example, one of STAs 100 and 200 can perform the expected operation of an AP, and the other of STAs 100 and 200 can perform the expected operation of a non-AP STA. Figure 1 Transceivers 106 and 206 can perform transmission and reception operations of signals (e.g., packet or physical layer protocol data units (PPDUs) conforming to IEEE 802.11a / b / g / n / ac / ax / be). Furthermore, in this disclosure, the operations of generating transmit / receive signals or performing data processing or calculations on transmit / receive signals in advance by various STAs can be performed by… Figure 1 Processors 102 and 202 perform the following operations: For example, examples of generating transmit / receive signals or performing data processing or calculations on transmit / receive signals in advance may include 1) determining / acquiring / configuring / calculating / decoding / encoding bit information of fields (signals (SIG), short training field (STF), long training field (LTF), data, etc.) included in the PPDU; 2) determining / configuring / acquiring time resources or frequency resources (e.g., subcarrier resources) for the fields (SIG, STF, LTF, data, etc.) included in the PPDU; 3) determining / configuring / acquiring specific sequences (e.g., pilot sequences, STF / LTF sequences, additional sequences applied to SIG) for the fields (SIG, STF, LTF, data, etc.) included in the PPDU action; 4) power control operations and / or power-saving operations applied to the STA; and 5) operations related to determining / acquiring / configuring / calculating / encoding the ACK signal. Additionally, in the following examples, various information used by various STAs to determine / acquire / configure / calculate / decode / encode transmitted and received signals (e.g., information related to fields / subfields / control fields / parameters / power, etc.) can be stored. Figure 1 In memory 104 and 204.

[0048] In the following text, downlink (DL) can refer to a link used for communication from an AP STA to a non-AP STA, and DL PPDUs / packets / signals can be sent and received via DL. In DL communication, the transmitter can be part of an AP STA, and the receiver can be part of a non-AP STA. Uplink (UL) can refer to a link used for communication from a non-AP STA to an AP STA, and UL PPDUs / packets / signals can be sent and received via UL. In UL communication, the transmitter can be part of a non-AP STA, and the receiver can be part of an AP STA.

[0049] Figure 2 This is a diagram illustrating an exemplary structure of a wireless LAN system to which this disclosure can be applied.

[0050] A wireless LAN system can be structured by multiple components. Wireless LANs that support STA mobility transparent to upper layers can be provided through the interaction of these components. The Basic Services Set (BSS) corresponds to the basic building blocks of a wireless LAN. Figure 2 An example is shown where there are two BSSs (BSS1 and BSS2) and two STAs are included as members of each BSS (STA1 and STA2 are included in BSS1, and STA3 and STA4 are included in BSS2). Figure 2 The ellipse representing the BSS can also be interpreted as representing the coverage area within the corresponding BSS where STAs maintain communication. This area can be called the Basic Service Area (BSA). When a STA moves out of the BSA, it cannot directly communicate with other STAs within the BSA.

[0051] If we do not consider Figure 2 The DS shown represents the most basic type of BSS in a wireless LAN, which is the Independent BSS (IBSS). For example, an IBSS can have a minimal form containing only two STAs. For instance, assuming other components are omitted, BSS1 containing only STA1 and STA2, or BSS2 containing only STA3 and STA4, can respectively correspond to representative examples of IBSS. This configuration is possible when STAs can communicate directly without an AP. Furthermore, in this type of wireless LAN, it is not pre-configured but can be configured when a LAN is needed, and this can be called a self-organizing network. Because an IBSS does not include an AP, there is no centralized management entity. That is, in an IBSS, STAs are managed in a distributed manner. In an IBSS, all STAs can consist of mobile STAs and are not allowed to access the Distributed System (DS), thus forming a self-contained network.

[0052] A STA's membership in the BSS can be dynamically changed by opening or closing the STA, entering or leaving a BSS zone, etc. To become a member of the BSS, an STA can join the BSS using a synchronization process. To access all services of the BSS infrastructure, an STA should be associated with the BSS. This association can be established dynamically and can include the use of Distributed System Services (DSS).

[0053] Direct STA-to-STA distance in a wireless LAN can be limited by PHY performance. In some cases, this distance limit may be sufficient, but in others, communication between STAs at greater distances may be required. Distributed systems (DS) can be configured to support extended coverage.

[0054] DS refers to the interconnected structure of BSSs. Specifically, such as... Figure 2As shown, a BSS can exist as an extension of a network composed of multiple BSSs. A DS is a logical concept and can be specified by the characteristics of the Distributed System Medium (DSM). In this respect, the Wireless Medium (WM) and the DSM can be logically separated. Each logical medium is used for a different purpose and by different components. These media are not limited to being the same, nor are they limited to being different. Thus, the flexibility of wireless LAN architectures (DS architectures or other network architectures) can be interpreted as multiple media being logically different. That is, wireless LAN architectures can be implemented in various ways, and the corresponding wireless LAN architectures can be independently specified by the physical characteristics of each embodiment.

[0055] DS can support mobile devices by providing seamless integration of multiple BSSs and the logical services necessary for address addressing to the destination. Additionally, DS can further include a component called a portal, which acts as a bridge for connections between the wireless LAN and other networks, such as IEEE 802.X.

[0056] An AP enables access to a DS via WM for its associated non-AP STA, and this implies an entity that also functions as a STA. Data movement between the BSS and DS can be performed through the AP. For example, Figure 2 STA2 and STA3, as shown, possess the functionality of STAs and provide the ability for associated non-AP STAs (STA1 and STA4) to access the DS. Furthermore, since all APs essentially correspond to STAs, all APs are addressable entities. The address used by an AP for communication on the WM is not necessarily the same as the address used by an AP for communication on the DSM. A BSS consisting of APs and one or more STAs can be referred to as an infrastructure BSS.

[0057] Data sent from one of the STAs associated with the AP to the STA address of the corresponding AP can always be received on an uncontrolled port and can be processed by an IEEE 802.1X port access entity. Alternatively, when the controlled port is authenticated, transmitted data (or frames) can be delivered to the DS.

[0058] In addition to the DS structure described above, an Extended Service Set (ESS) can be configured to provide broad coverage.

[0059] An ESS (Service Set Identity) refers to a network of arbitrary size and complexity consisting of DS (Service Controller) and BSS (Service Set Service). An ESS can correspond to a set of BSSs connected to a DS. However, an ESS does not include the DS. An ESS network is characterized by being treated as an IBSS (Independent Service Set Service) within the Logical Link Control (LLC) layer. STAs included in an ESS can communicate with each other, and a mobile STA can move from one BSS to another BSS (within the same ESS), which is transparent to the LLC. APs included in an ESS can have the same Service Set Identity (SSID). The SSID is distinct from the BSSID, which is the identifier of the BSS.

[0060] Wireless LAN systems do not assume anything about the relative physical location of BSSs, and all of the following forms are possible. BSSs can partially overlap, which is a common form used to provide continuous coverage. Additionally, BSSs may not have physical connections, and logically, there is no limit to the distance between BSSs. Furthermore, BSSs may be physically located in the same location, which can be used to provide redundancy. Additionally, one (or more) IBSS or ESS networks can physically exist in the same space as one (or more) ESS networks. This can be analogous to the form corresponding to ESS networks when an ad hoc network operates in a location where an ESS network exists, when physically overlapping wireless networks are configured by different organizations, or when two or more different access and security policies are required in the same location.

[0061] Figure 3 This is a diagram used to explain the link setup process to which this disclosure can be applied.

[0062] For a STA to establish a link to the network and send / receive data, the network must first be discovered, authentication performed, and association established. A security authentication process is also required. This link establishment process can also be called the session initiation process or session setup process. Furthermore, the discovery, authentication, association, and security settings within the link establishment process can be collectively referred to as the association process.

[0063] In step S310, the STA can perform a network discovery operation. The network discovery operation may include a scanning operation by the STA. That is, in order for the STA to access the network, it needs to find networks it can participate in. Before participating in a wireless network, the STA should identify compatible networks, and the process of identifying networks present in a specific area is called scanning.

[0064] Scanning schemes include active scanning and passive scanning. Figure 3An exemplary illustration depicts a network discovery operation including an active scanning process. In an active scan, the STA performing the scan sends probe request frames while moving channels to discover which APs are present in its vicinity and awaits a response. A responder sends a probe response frame to the STA that sent the probe request frame as a response to the probe request frame. Here, the responder could be the STA that last sent a beacon frame in the BSS of the scanned channel. In the BSS, the AP becomes the responder because it sends a beacon frame, and in the IBSS, STAs in the IBSS take turns sending beacon frames, so the responder is 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 store the BSS-related information included in the received probe response frame and can move to the next channel (e.g., channel 2) and perform a scan in the same manner (i.e., sending / receiving probe requests / responses on channel 2).

[0065] Although Figure 3 Although not shown, scanning operations can be performed passively. In passive scanning, the STA performing the scan waits for beacon frames while moving through channels. Beacon frames are one of the management frames defined in IEEE 802.11 and are periodically sent to notify of the existence of a wireless network and allow the STA performing the scan to find and participate in the network. In a BSS, the AP periodically sends beacon frames, and in an IBSS, STAs within the IBSS take turns sending beacon frames. When a STA performing the scan receives a beacon frame, it stores the BSS information included in the beacon frame and records the beacon frame information for each channel while moving to another channel. The STA receiving the beacon frame can store the BSS-related information included in the received beacon frame, move to the next channel, and perform the scan in the next channel in the same manner. Comparing active and passive scanning, active scanning has the advantages of lower latency and lower power consumption.

[0066] After the STA discovers the network, an authentication process can be performed in step S320. To clearly distinguish this authentication process from the security setup operation in step S340, which will be described later, this authentication process can be referred to as the first authentication process.

[0067] The authentication process includes the STA sending an authentication request frame to the AP, and in response, the AP sending an authentication response frame to the STA. The authentication frame used for the authentication request / response corresponds to the management frame.

[0068] The authentication frame includes the authentication algorithm number, authentication transaction sequence number, status code, challenge text, robust security network (RSN), and finite cycle group, etc. This corresponds to some examples of information that can be included in the authentication request / response frame, and may be replaced with other information or may include further additional information.

[0069] A STA can send an authentication request frame to an AP. The AP can determine whether to allow the corresponding STA to authenticate based on the information included in the received authentication request frame. The AP can then provide the result of the authentication process to the STA via an authentication response frame.

[0070] After successful STA authentication, the association process can be performed in step S330. The association process includes the STA sending an association request frame to the AP, and in response, the AP sending an association response frame to the STA.

[0071] For example, an association request frame may include information related to various capabilities, beacon listening intervals, service set identifiers (SSIDs), supported rates, supported channels, RSNs, mobile domains, supported operation classes, service indication map broadcast requests (TIM broadcast requests), and interoperability capabilities. Similarly, an association response frame may include information related to various capabilities, status codes, association IDs (AIDs), supported rates, enhanced distributed channel access (EDCA) parameter sets, received channel power indicators (RCPIs), received signal-to-noise ratio indicators (RSNIs), mobile domains, timeout intervals (e.g., association recovery time), overlapping BSS scan parameters, TIM broadcast responses, and quality of service (QoS) maps. These correspond to examples of information that can be included in association request / response frames and may be replaced with other information or further supplementary information.

[0072] After the STA successfully associates with the network, a security setup process can be performed in step S340. The security setup process in step S340 can be referred to as the authentication process via a Robust Secure Network Association (RSNA) request / response, and the authentication process in step S320 is referred to as the first authentication process. The security setup process in step S340 can also be simply referred to as the authentication process.

[0073] The security setup process in step S340 may include, for example, a process of establishing a private key via a four-way handshake using Extensible Authentication Protocol (EAPOL) frames over a LAN. Alternatively, the security setup process may be performed according to a security scheme not defined in the IEEE 802.11 standard.

[0074] Figure 4 This is a diagram used to explain the retreat process to which this disclosure can be applied.

[0075] In wireless LAN systems, the basic access mechanism for Media Access Control (MAC) is Carrier Sense Multiple Access with Collision Avoidance (CSMA / CA). Also known as the Distributed Coordination Function (DCF) of IEEE 802.11 MAC, CSMA / CA essentially employs a "listen-before-speak" access mechanism. Under this type of access mechanism, the AP and / or STA can perform a sensed free channel assessment (CCA) of the wireless channel or medium within a predetermined time interval (e.g., the DCF inter-frame interval (DIFS)) before initiating transmission. As a result of the sensing, if the medium is determined to be idle, frame transmission begins through the corresponding medium. Conversely, if the medium is detected to be occupied or busy, the corresponding AP and / or STA does not initiate its own transmission and can set a delay period for medium intervention (e.g., a random backoff period) and attempt frame transmission after waiting. By applying a random backoff period, collisions can be minimized because several STAs are expected to attempt frame transmission after waiting for different time periods.

[0076] In addition, the IEEE 802.11 MAC protocol provides Hybrid Coordination Function (HCF). HCF is based on DCF and Point Coordination Function (PCF). PCF is a polling-based synchronous access method, referring to a method in which all receiving APs and / or STAs periodically poll to receive data frames. Furthermore, HCF includes Enhanced Distributed Channel Access (EDCA) and HCF-Controlled Channel Access (HCCA). EDCA is a contention-based access method used by providers to deliver data frames to multiple users, while HCCA uses a polling mechanism to employ a non-contention-based channel access method. Additionally, HCF includes a media access mechanism for improving the QoS (Quality of Service) of wireless LANs and can transmit QoS data during both contention-based (CP) and contention-free (CFP) periods.

[0077] refer to Figure 4This section describes the operation based on a random backoff period. When a occupied / busy medium becomes idle, several STAs may attempt to transmit data (or frames). As a method to minimize collisions, each STA can individually select a random backoff count and attempt transmission after waiting for the corresponding time slot. The random backoff count has a pseudo-random integer value and can be determined as one of the values ​​from 0 to CW. Here, CW is the contention window parameter value. The CW parameter is assigned an initial value of CWmin, but can be doubled if a transmission failure occurs (e.g., when an ACK for a transmitted frame is not received). When the CW parameter value reaches CWmax, data transmission can be attempted while maintaining the CWmax value until successful data transmission, and the CWmin value is reset when data transmission is successful. The values ​​of CW, CWmin, and CWmax are preferably set to 2. n -1 (n = 0, 1, 2, ...).

[0078] When the random backoff process begins, the STA continuously monitors the medium while counting down the backoff time slot based on the determined backoff count value. When medium occupancy is detected, it stops counting down and waits, and resumes the remaining countdown when the medium becomes free.

[0079] exist Figure 4 In the example, when the packet to be sent arrives at STA3's MAC, STA3 can send the frame immediately after confirming that the medium is free for as long as DIFS. The remaining STAs monitor and wait for the medium to be occupied / busy. Meanwhile, data to be sent may also occur in each of STA1, STA2, and STA5, and when the medium is detected as free, each STA waits for as long as DIFS, and can then count down the backoff slots according to a random backoff count value selected by each STA. Assume that STA2 chooses the minimum backoff count value, and STA1 chooses the maximum backoff count value. That is, the case where STA5's remaining backoff time is less than STA1's remaining backoff time when STA2 completes its backoff count and begins frame transmission is illustrated. STA1 and STA5 temporarily stop the countdown and wait, while STA2 occupies the medium. When STA2 finishes occupying the medium and it becomes free again, STA1 and STA5 wait for DIFS and resume the stopped backoff count. That is, after counting down the remaining backoff slots for the remaining backoff time, frame transmission can begin. Because STA5's remaining backoff time is less than STA1's, STA5 begins frame transmission. While STA2 is occupying the medium, data to be transmitted may also appear in STA4. From STA4's perspective, when the medium becomes idle, STA4 can wait for DIFS, and then execute a countdown based on a random backoff count value selected by STA4 and begin transmitting frames. Figure 4The example illustrates a scenario where the remaining backoff time of STA5 coincides exactly with the random backoff count of STA4. In this case, a collision may occur between STA4 and STA5. When a collision occurs, neither STA4 nor STA5 receives an ACK, thus data transmission fails. In this situation, STA4 and STA5 can double their CW value, choose a random backoff count, and begin a countdown. STA1 waits while the medium is occupied due to the transmissions of STA4 and STA5, waits for DIFS when the medium becomes idle, and then begins frame transmission after the remaining backoff time has elapsed.

[0080] like Figure 4 As shown in the example, data frames are frames used to transmit data forwarded to higher layers and can be sent after a backoff performed after the DIFS (Distributed Access Frame) begins to elapse when the medium becomes idle. Management frames, on the other hand, are frames used to exchange management information that is not forwarded to higher layers and are sent after a backoff performed after an IFS (Initial Point Coordination Function) such as a DIFS or a Point Coordination Function IFS (PIFS). Subtypes of management frames include beacons, association requests / responses, reassociation requests / responses, probe requests / responses, authentication requests / responses, etc. Control frames are frames used to control access to the medium. Subtypes of control frames include request to send (RTS), clear send (CTS), acknowledgment (ACK), power-saving polling (PS-Poll), block ACK (BlockAck), block ACK request (BlockACKReq), empty data packet advertisement (NDP advertisement), and triggers, etc. If a control frame is not a response frame to a previous frame, it is sent after a backoff performed after the DIFS elapses; if it is a response frame to a previous frame, it is sent without a backoff performed after the short IFS (SIFS) elapses. The type and subtype of a frame can be identified by the type field and subtype field in the Frame Control (FC) field.

[0081] The Quality of Service (QoS) ST can perform a backoff following the Arbitration IFS (AIFS) of the Access Class (AC) to which the frame belongs, i.e., AIFS[i] (where i is a value determined by the AC), and then the frame can be sent. Here, frames that can use AIFS[i] can be data frames, management frames, or control frames other than response frames.

[0082] Figure 5 This is a diagram used to explain the CSMA / CA-based frame transmission operation to which this disclosure can be applied.

[0083] As mentioned above, the CSMA / CA mechanism includes virtual carrier sensing in addition to physical carrier sensing, which is directly sensed by the STA. Virtual carrier sensing is designed to compensate for problems that may arise in media access, such as hidden node issues. For virtual carrier sensing, the STA's MAC can use a Network Allocation Vector (NAV). The NAV is a value that indicates to other STAs the remaining time until the media becomes available for use by the currently used or authorized STA. Therefore, a value set to NAV corresponds to a period of time during which the media is scheduled for use by the STA sending the frame, and the STA receiving the NAV value is prohibited from accessing the media during the corresponding period. For example, the NAV can be configured based on the value of the "Duration" field in the MAC header of the frame.

[0084] exist Figure 5 In the example, it is assumed that STA1 intends to send data to STA2, and STA3 is in a position that can listen to some or all of the frames sent and received between STA1 and STA2.

[0085] To reduce the likelihood of transmission conflicts between multiple STAs in CSMA / CA-based frame transmission operations, a mechanism using RTS / CTS frames can be applied. Figure 5 In the example, while STA1 is transmitting, as a result of STA3's carrier sensing, it can be determined that the medium is in an idle state. That is, STA1 can correspond to a hidden node of STA3. Alternatively, in Figure 5 In the example, it can be determined that the carrier sensing result medium of STA3 is idle while the transmission of STA2 is being performed. That is, STA2 can correspond to a hidden node of STA3. By exchanging RTS / CTS frames before data transmission and reception between STA1 and STA2, STAs outside the transmission range of either STA1 or STA2, or STAs outside the carrier sensing range for transmissions from STA1 or STA3, can not attempt to occupy the channel during data transmission and reception between STA1 and STA2.

[0086] Specifically, STA1 can determine whether a channel is in use through carrier sensing. Regarding physical carrier sensing, STA1 can determine the channel occupancy status based on the energy level or signal correlation detected in the channel. Furthermore, regarding virtual carrier sensing, STA1 can use a network allocation vector (NAV) timer to determine the channel occupancy status.

[0087] When the channel is idle during DIFS, STA1 can send an RTS frame to STA2 after performing backoff. When STA2 receives the RTS frame, STA2 can send a CTS frame to STA1 after SIFS as a response to the RTS frame.

[0088] If STA3 cannot listen to CTS frames from STA2 but can listen to RTS frames from STA1, STA3 can use the duration information included in the RTS frame 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 can listen to CTS frames from STA2, even if STA3 cannot listen to RTS frames from STA1, STA3 can use the duration information included in the CTS frame to set the NAV timer for subsequent consecutive frame transmission periods (e.g., SIFS+data frame+SIFS+ACK frame). That is, if STA3 can listen to one or more RTS or CTS frames from STA1 or STA2, STA3 can set the NAV accordingly. When STA3 receives a new frame before the NAV timer expires, STA3 can update the NAV timer using the duration information included in the new frame. STA3 does not attempt channel access before the NAV timer expires.

[0089] When STA1 receives a CTS frame from STA2, STA1 can send a data frame to STA2 after the SIFS period starting from the time when the CTS frame reception is completed. When STA2 successfully receives the data frame, STA2 can send an ACK frame to STA1 as a response to the data frame after the SIFS period. When the NAV timer expires, STA3 can determine whether the channel is being used through carrier sensing. When STA3 determines that the channel is not being used by other terminals during the DIFS period after the NAV timer expires, STA3 can attempt channel access after the contention window (CW) for random backoff has elapsed.

[0090] Figure 6 This is a diagram used to explain an example of the frame structure that can be used in a WLAN system to which this disclosure can be applied.

[0091] Using instructions or primitives (meaning a set of instructions or parameters) from the MAC layer, the PHY layer can prepare a MAC PDU (MPDU) to be sent. For example, when it receives a command from the MAC layer requesting the PHY layer to begin transmission, the PHY layer switches to transport mode and configures the information (e.g., data) provided from the MAC layer in the form of a frame and sends it. Additionally, when the PHY layer detects a valid preamble to a received frame, it monitors the preamble header and sends a command to the MAC layer notifying the PHY layer of the start of reception.

[0092] In this way, information transmission / reception in a wireless LAN system is performed in the form of frames, and for this purpose, the PHY layer Protocol Data Unit (PPDU) frame format is defined.

[0093] A basic PPDU frame can include a Short Training Field (STF), a Long Training Field (LTF), a Signal (SIG) field, and a Data field. The most basic PPDU format (e.g., Figure 7 The non-HT (high throughput) fields shown may consist only of legacy STF (L-STF), legacy LTF (L-LTF), legacy SIG (L-SIG) fields, and a data field. Additionally, depending on the PPDU format type (e.g., HT mixed format PPDU, HT-greenfield format PPDU, VHT (very high throughput) PPDU, etc.), additional (or different types of) RL-SIG, U-SIG, non-legacy SIG fields, non-legacy STF, non-legacy LTF (i.e., xx-SIG, xx-STF, xx-LTF (e.g., xx is HT, VHT, HE, EHT, etc.)) may be included between the L-SIG field and the data field.

[0094] STF is a signal used for signal detection, automatic gain control (AGC), diversity selection, precise time synchronization, etc., while LTF is a signal used for channel estimation and frequency error estimation. STF and LTF can be referred to as signals used for synchronization and channel estimation in the OFDM physical layer.

[0095] The SIG field can include various information related to PPDU transmission and reception. For example, the L-SIG field consists of 24 bits and can include a 4-bit rate field, a 1-bit reserved bit, a 12-bit length field, a 1-bit parity field, and a 6-bit tail field. The RATE field can include information about the modulation and coding rate of the data. For example, the 12-bit length field can include information about the length or duration of the PPDU. For example, the value of the 12-bit length field can be determined based on the type of PPDU. For example, for non-HT, HT, VHT, or EHT PPDUs, the value of the length field can be determined to be a multiple of 3. For example, for HE PPDUs, the value of the length field can be determined to be a multiple of 3+1 or 3+2.

[0096] The data field may include the SERVICE field, Physical Layer Service Data Unit (PSDU), and PPDU tail bits, and may also include padding bits if necessary. Some bits of the SERVICE field can be used for synchronization of the descrambler at the receiver. The PSDU corresponds to the MAC PDU defined in the MAC layer and may include data generated / used in the upper layer. The PPDU tail bits can be used to return the encoder to a 0 state. Padding bits can be used to adjust the length of the data field in predetermined units.

[0097] MAC PDUs are defined according to various MAC frame formats, and a basic MAC frame consists of a MAC header, a frame body, and a Frame Check Sequence (FCS). MAC frames can be composed of MAC PDUs and are transmitted / received via the PSDU in the data portion of the PPDU frame format.

[0098] The MAC header includes a frame control field, a duration / ID field, and an address field. The frame control field can include control information required for frame transmission / reception. The duration / ID field can be set to the time for transmitting the corresponding frame. For detailed information on the sequence control, QoS control, and HT control subfields of the MAC header, please refer to the IEEE 802.11 standard document.

[0099] The NDP (Narrow Data PPDU) format refers to a PPDU format that does not include the data field. In other words, NDP refers to a frame format that includes the PPDU preamble (i.e., L-STF, L-LTF, L-SIG fields and additional non-legacy SIG, non-legacy STF, and non-legacy LTF (if present)) but does not include the remaining portion (i.e., the data field) in the general PPDU frame format.

[0100] Figure 7 This is a diagram illustrating an example of a PPDU as defined in the IEEE 802.11 standard that can be applied to this disclosure.

[0101] Various types of PPDUs are used in standards such as IEEE 802.11a / g / n / ac / ax. The basic PPDU format (IEEE 802.11a / g) includes L-LTF, L-STF, L-SIG, and a data field. The basic PPDU format can also be referred to as a non-HT PPDU format (e.g., ...). Figure 7 (as shown in (a)).

[0102] In addition to the basic PPDU format, the HT PPDU format (IEEE 802.11n) also includes the HT-SIG, HT-STF and HT-LFT fields. Figure 7The HT PPDU format shown in (b) can be called the HT-mixed format. Alternatively, an HT-greenfield format PPDU can be defined, which corresponds to a format consisting of HT-GF-STF, HT-LTF1, HT-SIG, one or more HT-LTFs and a data field, excluding L-STF, L-LTF and L-SIG (not shown).

[0103] Examples of VHT PPDU format (IEEE 802.11ac) include, in addition to the basic PPDU format, VHT SIG-A, VHT-STF, VHT-LTF, and VHT-SIG-B fields (such as...). Figure 7 (as shown in (c)).

[0104] Examples of HE PPDU format (IEEE 802.11ax) include, in addition to the basic PPDU format, repeated L-SIG (RL-SIG), HE-SIG-A, HE-SIG-B, HE-STF, HE-LTF(s), and packet extension (PE) fields (such as...). Figure 7 (as shown in (d)). Based on the detailed example of the HE PPDU format, some fields may be excluded or their lengths may vary. For example, the HE-SIG-B field is included in the HE PPDU format for multi-user (MU) applications, but not in the HE PPDU format for single-user (SU) applications. Additionally, the HE trigger (TB) based PPDU format does not include HE-SIG-B, and the length of the HE-STF field may vary to 8µs. The extended range (HE ER) SU PPDU format does not include the HE-SIG-B field, and the length of the HE-SIG-A field may vary to 16µs. For example, RL-SIG can be configured to be the same as L-SIG. The receiving STA can determine whether the received PPDU is an HE PPDU or an EHT PPDU based on the presence of RL-SIG, which will be described later.

[0105] EHT PPDU format can include Figure 7 (e) EHT MU (Multi-user) and Figure 7 (f) EHT TB (trigger-based) PPDU. The EHT PPDU format is similar to the HE PPDU format in that it includes RL-SIG, followed by L-SIG, but may include U (generic)-SIG, EHT-SIG, EHT-STF and EHT-LTF following RL-SIG.

[0106] Figure 7In (e), the EHT MU PPDU corresponds to a PPDU that carries one or more data (or PSDU) for one or more users. That is, the EHT MU PPDU can be used for both SU and MU transmissions. For example, the EHT MU PPDU can correspond to a PPDU used for one or more receiving STAs.

[0107] Compared to EHT MU PPDU, Figure 7 In (f), the EHT-SIG is omitted from the EHT TB PPDU. A STA that receives a trigger (e.g., a trigger frame or trigger response schedule (TRS)) for UL MU transmission can perform UL transmission based on the EHT TB PPDU format.

[0108] The L-STF, L-LTF, L-SIG, RL-SIG, U-SIG (General Signal), and EHT-SIG fields can be encoded and modulated so that even legacy STAs can attempt demodulation and decoding, and can be mapped based on a determined subcarrier frequency interval (e.g., 312.5 kHz). These can be referred to as pre-EHT modulated fields. Next, the EHT-STF, EHT-LTF, Data, and PE fields can be encoded and modulated for demodulation and decoding by an STA that has successfully decoded a non-legacy SIG (e.g., U-SIG and / or EHT-SIG) and obtained the information contained in the fields, and can be mapped based on a determined subcarrier frequency interval (e.g., 78.125 kHz). These can be referred to as EHT modulated fields.

[0109] Similarly, in the HE PPDU format, the L-STF, L-LTF, L-SIG, RL-SIG, HE-SIG-A, and HE-SIG-B fields can be referred to as pre-HE modulation fields, and the HE-STF, HE-LTF, Data, and PE fields can be referred to as HE modulation fields. Additionally, in the VHT PPDU format, the L-STF, L-LTF, L-SIG, and VHT-SIG-A fields can be referred to as free VHT modulation fields, and the VHT STF, VHT-LTF, VHT-SIG-B, and Data fields can be referred to as VHT modulation fields.

[0110] Figure 7The U-SIG included in the EHT PPDU format can be configured based on, for example, two symbols (e.g., two consecutive OFDM symbols). Each symbol used for the U-SIG (e.g., an OFDM symbol) can have a duration of 4 µs, and the U-SIG can have a total duration of 8 µs. Each symbol of the U-SIG can be used to transmit 26 bits of information. For example, each symbol of the U-SIG can be transmitted and received based on 52 data tones and 4 pilot tones.

[0111] U-SIGs can be constructed in 20MHz units. For example, if an 80MHz PPDU is constructed, the U-SIGs may be repeated. That is, an 80MHz PPDU can include the same four U-SIGs. PPDUs with bandwidths exceeding 80MHz can include different U-SIGs.

[0112] For example, A uncoded bits can be sent via U-SIG. The first symbol of U-SIG (e.g., U-SIG-1 symbol) can send the first X bits of the total A bits of information, and the second symbol of U-SIG (e.g., U-SIG-2 symbol) can send the remaining Y bits of the total A bits of information. The A bits of information (e.g., 52 uncoded bits) can include a CRC field (e.g., a 4-bit field) and a tail field (e.g., a 6-bit field). For example, the tail field can be used to terminate the grid of the convolutional decoder and can be set to 0.

[0113] The bit information sent by U-SIG can be divided into version-independent bits and version-dependent bits. For example, U-SIG can be included in... Figure 7 In the new PPDU format (e.g., UHR PPDU format) not shown in the figure, and in the format of the U-SIG field included in the EHT PPDU format and the format of the U-SIG field included in the UHR PPDU format, the version-independent bits may be the same, and some or all of the version-related bits may be different.

[0114] For example, the size of the version-independent bits in U-SIG can be fixed or variable. Version-independent bits can be assigned only to the U-SIG-1 symbol, or to both the U-SIG-1 and U-SIG-2 symbols. Version-independent bits and version-dependent bits can be referred to by various names, such as first control bits and second control bits.

[0115] For example, the version-independent bits of U-SIG may include a 3-bit Physical Layer Version Identifier (PHY Version Identifier), and this information can indicate the PHY version (e.g., EHT, UHR, etc.) of the transmitted / received PPDU. The version-independent bits of 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. The version-independent bits of U-SIG may include information about the length of the Transmission Opportunity (TXOP) and information about the BSS color ID.

[0116] For example, the version-related bits of U-SIG may include information that directly or indirectly indicates the type of PPDU (e.g., SUPPDU, MU PPDU, TB PPDU, etc.).

[0117] The information necessary for PPDU transmission and reception can be included in the U-SIG. For example, the U-SIG may further include information about the bandwidth, information about the MCS technique applied to the non-legacy SIG (e.g., EHT-SIG or UHR-SIG), information indicating whether a DCM (dual-carrier modulation) technique (e.g., a technique that achieves a frequency diversity-like effect by repeating the same signal on two subcarriers) is applied to the non-legacy SIG, information about the number of symbols used for the non-legacy SIG, and may also include information about whether the non-legacy SIG is generated across the entire band, etc.

[0118] Some information necessary for PPDU transmission and reception can be included in the U-SIG and / or non-legacy SIG (e.g., EHT-SIG or UHR-SIG, etc.). For example, information about the type of non-legacy LTF / STF (e.g., EHT-LTF / EHT-STF or UHR-LTF / UHR-STF, etc.), information about the length of the non-legacy LTF and the CP (cyclic prefix) length, information about the GI (guard interval) applicable to the non-legacy LTF, information about the preamble perforation applicable to the PPDU, information about RU (resource unit) allocation, etc., can be included only in the U-SIG, only in the non-legacy SIG, or indicated by a combination of information included in the U-SIG and information included in the non-legacy SIG.

[0119] A preamble can refer to the transmission of a PPDU in which no signal is present in one or more frequency units within the bandwidth of the PPDU. For example, the size of the frequency unit (or the resolution of the preamble) can be defined as 20MHz, 40MHz, etc. For example, a preamble can be applied to a PPDU of a predetermined size or larger bandwidth.

[0120] exist Figure 7 In the examples, non-legacy SIGs such as HE-SIG-B and EHT-SIG can include control information for receiving STAs. Non-legacy SIGs can be transmitted on at least one symbol, and a symbol can have a length of 4 µs. Information regarding the number of symbols used for EHT-SIGs can be included in previous SIGs (e.g., HE-SIG-A, U-SIG, etc.).

[0121] Non-legacy SIGs such as HE-SIG-B and EHT-SIG can include public fields and user-specific fields. Public fields and user-specific fields can be encoded separately.

[0122] In some cases, the common field can be omitted. For example, in compressed mode using non-OFDMA (Orthogonal Frequency Multiple Access), the common field can be omitted, and multiple STAs can receive PPDUs (e.g., the data field of the PPDU) through the same frequency band. In uncompressed mode using OFDMA, multiple users can receive PPDUs (e.g., the data field of the PPDU) through different frequency bands.

[0123] The number of user-specific fields can be determined based on the number of users. A user block field can include up to two user fields. Each user field can be associated with a MU-MIMO allocation or with a non-MU-MIMO allocation.

[0124] The common fields may include CRC bits and tail bits, where the length of the CRC bits can be determined to be 4 bits, and the length of the tail bits can be determined to be 6 bits and set to 000000. The common fields may include RU allocation information. RU allocation information may include information about the locations of RUs assigned to multiple users (i.e., multiple receiving STAs).

[0125] An RU can include multiple subcarriers (or tones). RUs can be used when transmitting signals to multiple STAs based on OFDMA technology. Additionally, RUs can be defined even when transmitting signals to a single STA. Resources can be allocated in units of RUs for non-legacy STFs, non-legacy LTFs, and data fields.

[0126] The appropriate RU size can be defined based on the PPDU bandwidth. For the applied PPDU format (e.g., HE PPDU, EHT PPDU, UHR PPDU, etc.), the RUs can be defined the same or different. For example, in the case of an 80MHz PPDU, the RU placement for HEPPDU and EHT PPDU may differ. The applicable RU size, number and location, DC (direct current) subcarrier location and number, empty subcarrier location and number, guard subcarrier location and number, etc., for each PPDU bandwidth can be referred to as the tone scheme. For example, a tone scheme for high bandwidth can be defined as multiple iterations of a low bandwidth tone scheme.

[0127] RUs of various sizes can be defined as 26-tone RUs, 52-tone RUs, 106-tone RUs, 242-tone RUs, 484-tone RUs, 996-tone RUs, 2×996-tone RUs, 3×996-tone RUs, etc. An MRU (multiple RUs) is distinguished from multiple individual RUs and corresponds to a group of subcarriers composed of multiple RUs. For example, an MRU can be defined as 52+26 tones, 106+26 tones, 484+242 tones, 996+484 tones, 996+484+242 tones, 2×996+484 tones, 3×996 tones, or 3×996+484 tones. Furthermore, the multiple RUs constituting an MRU can be continuous or non-contiguous in the frequency domain.

[0128] The specific size of an RU can be reduced or increased. Therefore, the specific size of each RU (i.e., the number of corresponding tones) in this disclosure is not limiting and is illustrative. In addition, in this disclosure, the number of RUs can vary depending on the RU size within a predetermined bandwidth (e.g., 20, 40, 80, 160, 320 MHz, ...).

[0129] Figure 7 The names of each field in the PPDU format are exemplary, and the scope of this disclosure is not limited to the names. Furthermore, the examples in this disclosure can be applied to... Figure 7 The PPDU format illustrated in the figure, and its application in... Figure 7 The PPDU format excludes some fields and / or adds some fields to the new PPDU format.

[0130] Resource Unit

[0131] Figures 8 to 10 This is a diagram illustrating an example of a resource unit for a WLAN system to which the present disclosure may be applied.

[0132] refer to Figures 8 to 10This describes the Resource Unit (RU) defined in a wireless LAN system. An RU can include multiple subcarriers (or tones). RUs can be used when transmitting signals to multiple STAs based on an OFDMA scheme. Additionally, an RU can be defined even when transmitting a signal to a single STA. RUs can be used in the data fields of STF, LTF, PPDU, etc.

[0133] like Figures 8 to 10 As shown, RUs corresponding to different numbers of tones (i.e., subcarriers) are used to construct some fields of 20MHz, 40MHz, or 80MHz X-PPDUs (where X is HE, EHT, etc.). For example, resources can be allocated to RU cells shown for X-STF, X-LTF, and data fields.

[0134] Figure 8 This is a diagram illustrating an exemplary allocation of resource units (RUs) used on a 20MHz band.

[0135] like Figure 8 As shown at the top, 26 units (i.e., units corresponding to 26 tones) can be allocated. Six tones can be used as guard bands in the leftmost band of the 20MHz band, and five tones can be used as guard bands in the rightmost band of the 20MHz band. Additionally, seven DC tones are inserted in the center band, i.e., the DC band, and 26 units corresponding to each of the 13 tones can exist on the left and right sides of the DC band. Furthermore, 26 units, 52 units, and 106 units can be allocated to other bands. Each unit can be assigned to a STA or user.

[0136] Figure 8 The RU allocation is utilized not only in multi-user (MU) scenarios but also in single-user (SU) scenarios, and in this case, a 242-unit configuration can be used, such as... Figure 8 As shown at the bottom. In this case, three DC tones can be inserted.

[0137] exist Figure 8 In the examples, various sizes of RUs, i.e., 26-RU, 52-RU, 106-RU, 242-RU, etc., are exemplified, but the specific size of these RUs can be reduced or increased. Therefore, in this disclosure, the specific size of each RU (i.e., the number of corresponding tones) is exemplary and not limiting. Furthermore, within the predetermined bandwidth of this disclosure (e.g., 20, 40, 80, 160, 320 MHz, ...), the number of RUs can vary depending on the size of the RUs. This will be described below. Figure 9 and / or Figure 10 In the example, the fact that the size and / or number of RUs can vary is consistent with... Figure 8 The examples are the same.

[0138] Figure 9 This is a diagram illustrating an exemplary allocation of resource units (RUs) used on a 40MHz band.

[0139] As in Figure 8 The examples use RUs of various sizes, just like in... Figure 9 Examples can also use 26-RU, 52-RU, 106-RU, 242-RU, 484-RU, etc. Additionally, five DC tones can be inserted at the center frequency, twelve tones can be used as guard bands in the leftmost band of the 40MHz band, and eleven tones can be used as guard bands in the rightmost band of the 40MHz band.

[0140] In addition, as shown, a 484-RU can be used when used for a single user.

[0141] Figure 10 This is a diagram illustrating an exemplary allocation of resource units (RUs) used on an 80MHz band.

[0142] Just like in Figure 8 and Figure 9 The examples use RUs of various sizes, just like in... Figure 10 Examples can also use 26-RU, 52-RU, 106-RU, 242-RU, 484-RU, 996-RU, etc. Additionally, in the case of an 80MHz PPDU, the RU allocation for the HE PPDU and EHT PPDU may differ, and... Figure 10 The example shows an instance of RU allocation for an 80MHz EHT PPDU. Figure 10 The scheme of using 12 tones as a guard band in the leftmost band of the 80MHz band and 11 tones as a guard band in the rightmost band of the 80MHz band is the same in both HE PPDU and EHT PPDU. Unlike HE PPDU, where 7 DC tones are inserted in the DC band and there is one 26-RU corresponding to each of the 13 tones on the left and right sides of the DC band, in EHT PPDU, 23 DC tones are inserted in the DC band, and there is one 26-RU on each side of the DC band. Unlike HE PPDU, where there is an empty subcarrier between 242-RUs instead of in the center band, there are five empty subcarriers in EHT PPDU. In HE PPDU, a 484-RU does not include an empty subcarrier, but in EHT PPDU, a 484-RU includes 5 empty subcarriers.

[0143] Additionally, as shown, when used for a single user, the 996-RU can be used, and in this case, five DC tones are inserted together with the HEPPDU and EHT PPDU.

[0144] It can be configured with a 160MHz EHT PPDU. Figure 10 Multiple 80MHz sub-blocks within. RU allocation for each 80MHz sub-block can be... Figure 10 The 80MHz EHT PPDU is the same. If the 80MHz sub-block of the 160MHz or 320MHz EHT PPDU is not perforated and the entire 80MHz sub-block is used as part of an RU or multiple RUs (MRUs), then the 80MHz sub-block can be used. Figure 10 996-RU.

[0145] Here, an MRU corresponds to a group of subcarriers (or tones) consisting of multiple RUs, and the multiple RUs constituting an MRU can be RUs of the same size or RUs of different sizes. For example, a single MRU can be defined as 52+26 tones, 106+26 tones, 484+242 tones, 996+484 tones, 996+484+242 tones, 2×996+484 tones, 3×996 tones, or 3×996+484 tones. The multiple RUs constituting an MRU can correspond to small-sized (e.g., 26, 52, or 106) RUs or large-sized (e.g., 242, 484, or 996) RUs. That is, an MRU including both small-sized and large-sized RUs can be configured / defined without further configuration. Furthermore, the multiple RUs constituting an MRU can be consecutive in the frequency domain or not.

[0146] When the 80MHz subblock includes RUs with fewer than 996 tones or when a portion of the 80MHz subblock is perforated, the 80MHz subblock can use RUs other than the 996-tone RUs.

[0147] The RU disclosed herein can be used for uplink (UL) and / or downlink (DL) communication. For example, when performing trigger-based UL-MU communication, the STA that sends the trigger (e.g., AP) can assign a first RU (e.g., 26 / 52 / 106 / 242-RU, etc.) and a second RU (e.g., 26 / 52 / 106 / 242-RU, etc.) to a second STA via trigger information (e.g., trigger frame or triggered response schedule (TRS)). Subsequently, the first STA can send a first trigger-based (TB) PPDU based on the first RU, and the second STA can send a second TB PPDU based on the second RU. The first / second TB PPDUs can be sent to the AP within the same time period.

[0148] For example, when configuring a DL MU PPDU, the STA (e.g., AP) transmitting the DL MU PPDU can 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. In other words, within a MU PPDU, the transmitting STA (e.g., AP) can transmit X-STF (e.g., X is HE, EHT, etc.), X-LTF, and data fields to the first STA via the first RU, and transmit X-STF, X-LTF, and data fields to the second STA via the second RU. Information about the RU arrangement can be signaled using the X-SIG (e.g., X is HE, EHT, U) field in the X-PPDU format.

[0149] Distributed resource unit

[0150] Due to varying regional regulations, power spectral density (PSD) limits may apply in the sub-7GHz (e.g., 6GHz) band. For non-AP STAs in the low-power indoor (LPI) band, the PSD limit might be -1dBm / MHz. For example, for an existing 52-tone RU, the maximum transmit (Tx) power might be approximately 6dBm.

[0151] Furthermore, different restrictions may be applied in the 2.4 GHz and 5 GHz bands. For example, in the EU / China / Japan / South Korea, a PSD limit of 10 dBm / MHz may be applied in the 2.4 GHz band. For an existing 52-tone RU, the maximum Tx power is likely to be around 17 dBm. If the PSD limit can be avoided in the 5 GHz band, the transmit power can be increased. For example, for an existing 52-tone RU, the maximum transmit power is 24 dBm, which is always 6 dBm lower than the maximum permissible effective isotropic radiated power (EIRP) of 30 dBm.

[0152] When the PSD limitation is overcome, the transmission power can be increased, thereby enhancing spectral efficiency or extending the range.

[0153] Considering the PSD limit defined for each STA per MHz, when the tones of a small RU are distributed over a wide bandwidth, the tones used for each STA are discontinuous, and therefore each tone may be transmitted at high power. RUs that include tones distributed in this way are called distributed RUs (DRUs), and to distinguish them, RUs that include continuous tones as defined in existing WLAN systems (e.g., systems according to IEEE 802.11ax, 11be, etc.) can be called conventional RUs (RRUs).

[0154] A STA transmitting a DRU can use higher power compared to a STA transmitting an existing RRU. For example, a 52-tone DRU spanning 80MHz has only one tone per MHz, while a 52-tone RRU has approximately 13 tones per MHz. Assuming a PSD limit of -1dBm / MHz in the 6GHz LPI band, the transmission power can be increased by approximately 11dB for a 52-tone RU when using a DRU. When transmission power is increased in this way, a higher MCS can be applied and a longer range can be supported.

[0155] Figure 11 This is a diagram used to describe an example of a DRU to which this disclosure can be applied.

[0156] Figure 11 The example illustratively illustrates that STA1 performs a transmission on DRU1, STA2 performs a transmission on DRU2, and STA3 performs a transmission on DRU3. Each STA can apply a transmission power boost by using a DRU. Higher transmission power can be applied to all tones in the DRU compared to using an RRU of the same size, and correspondingly, spectral efficiency can be greatly improved. In this way, DRUs can be usefully applied, particularly in UL-OFDMA.

[0157] In the case of the AP, DRUs can also be utilized. In some cases, the AP can perform DL-OFDMA transmission to the STA using only some of DRU1, DRU2, and DRU3, and in this case, the transmission power boost due to the use of DRUs can be applied.

[0158] To maximize power gains, tones can be distributed as widely as possible within a single DRU. For example, a DRU comprising one tone per MHz is considered an optimal example. The size of a DRU (or the number of available tones included in a DRU, i.e., the number of remaining tones after excluding unavailable tones such as zero tones, guard tones, DC tones, etc.) can be defined to be the same as the size of an RRU (or the number of available tones included in an RRU). Therefore, the impact on various techniques previously defined based on RRUs can be minimized. Examples of power gains (in dB) achievable with various DRUs distributed across different bandwidths are shown below. The examples in the table assume a 6 GHz LPI band, and power gains can also be achieved in the 2.4 GHz and 5 GHz bands in other regions. For example, in an 80 MHz UL-OFDMA transmission with 8 users, the overall performance can be improved by approximately 8.13 dB when each user uses a 106-tone DRU compared to using a 106-tone RRU per user. In this way, DRUs can be used to overcome the limitations of PSD and achieve significant benefits.

[0159] [Table 1]

[0160] DRU tone scheme-based transmission and reception

[0161] As described above, in order to overcome the PSD limitation and improve power gain, DRUs using distributed tone / subcarriers can be applied in addition to RRUs using continuous tone / subcarriers. That is, even when applying DRUs, tone plans can be defined, and tone plans can be defined not only when applying DRUs in specific bandwidths (e.g., 20, 40, 80, 160, 320 MHz), but also when applying DRUs in specific channel sizes (e.g., 20, 40, 80, 160, 320 MHz channels) in wideband situations.

[0162] Pilot tones can be used to compensate for residual CFO. In a predefined RU (i.e., RRU), a fixed-position pilot tone is always used, which reduces the reliability of residual CFO measurements that depend on channel conditions. Similarly, in a DRU, a fixed-position pilot tone can also cause problems with residual CFO measurements. In particular, given the susceptibility of DRUs to CFO, the use of a fixed-position pilot tone may not be desirable.

[0163] To address the aforementioned problems, this disclosure describes a method for altering the position of the pilot tone symbolically when the STA transmits a DRU-based PPDU. In other words, this disclosure describes a method for using a traveling pilot with a symbolically shifted pilot tone for efficient measurement and compensation of residual CFO.

[0164] Figure 12 This is a diagram illustrating an example of a PPDU receiving method based on a DRU tone scheme for a first STA according to this disclosure. Figure 12 and Figure 13 In this context, the first STA and the second STA can be either a non-AP STA or an AP.

[0165] The first STA can generate a PPDU (S1210) that includes multiple symbol groups. Here, multiple symbol groups can be mapped to at least one distributed resource unit (DRU).

[0166] Here, multiple symbol groups may include a first symbol group and a second symbol group following the first symbol group (e.g., a second symbol group adjacent to the first symbol group). As an example, the first symbol group may include: i) the first symbol of the UHR field of the PPDU; or ii) the entire symbol of the UHR-LTF field of the PPDU and the first symbol of the data portion of the UHR-LTF field of the PPDU.

[0167] Furthermore, at least one first pilot tone corresponding to a position in the first symbol group can be used among multiple pilot tones of a bandwidth-related predefined resource unit (RU) (i.e., RRU). In other words, at least one first pilot tone existing at a position in the first symbol group among multiple pilot tones of an RRU corresponding to a specific bandwidth can be used in the first symbol group mapped to the DRU. Therefore, pilot tones in the DRU corresponding to the positions of pilot tones in the first symbol group of an RRU of the same size can be used.

[0168] For example, based on the fact that at least one DRU is a 26-tone DRU, at least one first pilot tone can be one of {the 6th tone of the 26-tone DRU, the 20th tone of the 26-tone DRU}, {the 7th tone of the 26-tone DRU, the 21st tone of the 26-tone DRU}, or {the 7th tone of the 26-tone DRU, the 20th tone of the 26-tone DRU}.

[0169] As another example, based on the fact that at least one DRU is a 52-tone DRU, at least one first pilot tone can be one of {the 6th tone of the 52-tone DRU, the 20th tone of the 52-tone DRU, the 32nd tone of the 52-tone DRU, the 46th tone of the 52-tone DRU} or {the 7th tone of the 52-tone DRU, the 22nd tone of the 52-tone DRU, the 33rd tone of the 52-tone DRU, the 47th tone of the 52-tone DRU}.

[0170] As another example, based on the fact that at least one DRU is a 106-tone DRU, at least one first pilot tone can be one of {the 7th tone of the 106-tone DRU, the 33rd tone of the 106-tone DRU, the 75th tone of the 106-tone DRU, the 101st tone of the 106-tone DRU} or {the 6th tone of the 106-tone DRU, the 32nd tone of the 106-tone DRU, the 74th tone of the 106-tone DRU, the 100th tone of the 106-tone DRU}.

[0171] As another example, based on the premise that at least one DRU is a 242-tone DRU, at least one first pilot tone can be {the 7th tone of the 242-tone DRU, the 33rd tone of the 242-tone DRU, the 75th tone of the 242-tone DRU, the 101st tone of the 242-tone DRU, the 141st tone of the 242-tone DRU, the 167th tone of the 242-tone DRU, the 209th tone of the 242-tone DRU}. {235th tone of 242-tone DRU} or {8th tone of 242-tone DRU, 34th tone of 242-tone DRU, 76th tone of 242-tone DRU, 102nd tone of 242-tone DRU, 142nd tone of 242-tone DRU, 168th tone of 242-tone DRU, 210th tone of 242-tone DRU, 236th tone of 242-tone DRU}.

[0172] As another example, based on the premise that at least one DRU is a 484-tone DRU, at least one first pilot tone can be {the 7th tone of the 484-tone DRU, the 33rd tone of the 484-tone DRU, the 75th tone of the 484-tone DRU, the 101st tone of the 484-tone DRU, the 141st tone of the 484-tone DRU, the 167th tone of the 484-tone DRU, the 209th tone of the 484-tone DRU}. The 235th tone of the 484-tone DRU, the 250th tone of the 484-tone DRU, the 276th tone of the 484-tone DRU, the 318th tone of the 484-tone DRU, the 344th tone of the 484-tone DRU, the 384th tone of the 484-tone DRU, the 410th tone of the 484-tone DRU, the 452nd tone of the 484-tone DRU, and the 478th tone of the 484-tone DRU.

[0173] As another example, based on the premise that at least one DRU is a 996-tone DRU, at least one first pilot tone can be {the 33rd tone of the 996-tone DRU, the 101st tone of the 996-tone DRU, the 167th tone of the 996-tone DRU, the 235th tone of the 996-tone DRU, the 281st tone of the 996-tone DRU, the 349th tone of the 996-tone DRU, the 415th tone of the 996-tone DRU}. The tones of the 996-tone DRU are: the 483rd tone, the 514th tone, the 582nd tone, the 648th tone, the 716th tone, the 762nd tone, the 830th tone, the 896th tone, and the 964th tone.

[0174] As an example of this disclosure, the index of each of the plurality of second pilot tones used in each of the plurality of symbols included in the second symbol group can be based on a cyclic shift value applied to each of the plurality of symbols included in the second symbol group. That is, starting with the symbols included in the second symbol group after the first symbol group, the position of the pilot tone of the symbols included in the second symbol group can be changed according to a specific cyclic shift rule.

[0175] As an example of this disclosure, the cyclic shift value applied to each symbol may be fixed. For example, the cyclic shift value applied to each of the plurality of symbols included in the second symbol group may be set to a value less than the minimum value among the intervals between at least one first pilot tone.

[0176] In another example of this disclosure, the cyclic shift value applied to each symbol can vary.

[0177] For example, the cyclic shift value applied to the nth symbol (where n is a natural number greater than or equal to 1) among the multiple symbols included in the second symbol group can be x (where x is a natural number greater than or equal to 1), and the cyclic shift value applied to the (n+1)th symbol among the multiple symbols included in the second symbol group can be "x±a" (where a is a natural number greater than or equal to 1). That is, as the symbol index increases, the cyclic shift value applied to the pilot tone can also increase.

[0178] As another example, the cyclic shift value applied to the nth symbol among the multiple symbols included in the second symbol group can be "mod(index of the nth symbol, minimum value among the intervals between at least one first pilot - 1) + 1" or "mod(index of the nth symbol + 1, minimum value among the intervals between at least one first pilot - 1) + 1".

[0179] The first STA can send a PPDU (S1220) to at least one second STA within the bandwidth.

[0180] Figure 12 The methods described in the examples can be derived from... Figure 1 The first device (100) executes. For example, Figure 1 One or more processors (102) of the first device (100) can generate PPDUs comprising multiple symbol groups. One or more processors (102) can transmit PPDUs to at least one second STA via one or more transceivers (106) in the bandwidth.

[0181] Furthermore, one or more memories (104) of the first device (100) may store data for execution when performed by one or more processors (102). Figure 12 The example or the command described in the example below.

[0182] Figure 13 This is a diagram illustrating an example of a PPDU transmission method based on a DRU tone scheme for a second STA according to this disclosure.

[0183] The second STA can receive PPDUs (S1310) containing multiple symbol groups from the first STA via bandwidth. (See reference) Figure 12 The configuration of the symbol groups that constitute the PPDU by bandwidth and the pilot tones on the symbol groups has already been described, so any redundant descriptions will be omitted.

[0184] The second STA can decode the PPDU received from the first STA (S1320). The second STA can compensate for the remaining CFO using at least one pilot tone from the DRU assigned to the PPDU. Because the position of the pilot tone changes for each symbol, frequency diversity gain can be obtained in the measurement of the remaining CFO.

[0185] Figure 13 The methods described in the examples can be derived from... Figure 1 The second device (200) performs the operation. For example, Figure 1One or more processors (202) of the second device (200) can receive PPDUs comprising multiple symbol groups from the first STA via one or more transceivers (206). One or more processors (202) can decode the PPDUs received from the first STA.

[0186] Furthermore, one or more memories (204) of the second device (200) may store data for execution when performed by one or more processors (202). Figure 13 The example or the command described in the example below.

[0187] The following describes in detail the traveling pilot in which the pilot tone is shifted sign by sign.

[0188] Example 1

[0189] Example 1 relates to how to establish the travel pilot.

[0190] Data and / or pilot tones can be assigned to DRUs in each bandwidth (e.g., 20, 40, 80, 160 MHz). For example, after the available tones for each DRU (i.e., the remaining tones excluding DC / protection / zero tones in an RRU tone plan of the same size as the DRU) are distributed and assigned, the tone at a specific location can be defined as the initial pilot tone.

[0191] Here, the initial pilot tone can be used in i) the first symbol of the UHR-LTF field; or ii) the entire symbol and the first symbol of the data portion of the UHR-LTF field.

[0192] Example 1-1

[0193] Example 1-1 relates to a method for using the tone at a position in a DRU corresponding to the pilot position in a DRU of the same size as the pilot tone.

[0194] The following describes the positions of candidate pilot tones for each DRU, and the position of each pilot tone is described / defined based on the tone with the lowest frequency. For example, "the 6th tone" can mean the 6th tone based on the tone with the lowest frequency (i.e., the tone with the lowest frequency is considered the 1st tone). This may be relatively straightforward from an implementation perspective because the tones at the corresponding positions of the pilot positions within the DRU and RRU are used as pilot tones.

[0195] -26 DRU (pilot tone count is 2): "6th tone and 20th tone", "7th tone and 21st tone" or "7th tone or 20th tone"

[0196] -52 DRU (4 pilot tones): "Tone 6, Tone 20, Tone 32 and Tone 46" or "Tone 7, Tone 21, Tone 33 and Tone 47"

[0197] -106 DRU (4 pilot tones): "7th tone, 33rd tone, 75th tone, and 101st tone" or "6th tone, 32nd tone, 74th tone, and 100th tone".

[0198] -242 DRU (8 pilot tones): "Tone 7, Tone 33, Tone 75, Tone 101, Tone 141, Tone 167, Tone 209 and Tone 235" or "Tone 8, Tone 34, Tone 76, Tone 102, Tone 142, Tone 168, Tone 210 and Tone 236"

[0199] -484 DRU (16 pilot tones): "Tone 7, Tone 33, Tone 75, Tone 101, Tone 141, Tone 167, Tone 209, Tone 235, Tone 250, Tone 276, Tone 318, Tone 344, Tone 384, Tone 410, Tone 452, and Tone 478"

[0200] -996 DRU (16 pilot tones): "Tone 33, Tone 101, Tone 167, Tone 235, Tone 281, Tone 349, Tone 415, Tone 483, Tone 514, Tone 582, Tone 648, Tone 716, Tone 762, Tone 830, Tone 896, and Tone 964."

[0201] Examples 1-2

[0202] Examples 1-2 relate to a method of shifting the first pilot tone in the pilot tones of Example 1-1 to a first position (i.e., the position where the lowest frequency tone was previously located) and then shifting the other pilots at the same intervals and in the same direction. Since the tones in the DRU corresponding to the pilot tone positions in the RRU are used as pilot tones, this method is relatively simple to implement.

[0203] In the following text, the positions of the candidate pilot tones for each DRU to which the method of Examples 1-2 is applied are described. That is, the first pilot tone means the pilot tone that is first in the frequency domain.

[0204] - 26 DRU (pilot tones are 2): "Pitch 1 and Pitch 15", "Pitch 1 and Pitch 14", "Pitch 12 and Pitch 26" or "Pitch 13 and Pitch 26"

[0205] - 52 DRU (4 pilot tones): "Tone 1, Tone 15, Tone 27 and Tone 41" or "Tone 12, Tone 26, Tone 38 and Tone 52"

[0206] - 106 DRU (4 pilot tones): "Tone 1, Tone 27, Tone 69, Tone 95" or "Tone 12, Tone 38, Tone 80 and Tone 106".

[0207] - 242 DRU (8 pilot tones): "Tone 1, Tone 27, Tone 69, Tone 95, Tone 135, Tone 161, Tone 203 and Tone 229" or "Tone 14, Tone 40, Tone 82, Tone 108, Tone 148, Tone 174, Tone 216 and Tone 242"

[0208] - 484 DRU (16 pilot tones): "Tone 1, Tone 27, Tone 69, Tone 95, Tone 135, Tone 161, Tone 203, Tone 229, Tone 244, Tone 270, Tone 312, Tone 338, Tone 378, Tone 404, Tone 446 and Tone 47..." "2 tones" or "the 13th tone, the 39th tone, the 81st tone, the 107th tone, the 147th tone, the 173rd tone, the 215th tone, the 241st tone, the 256th tone, the 282nd tone, the 324th tone, the 350th tone, the 390th tone, the 416th tone, the 458th tone, and the 484th tone"

[0209] - 996 DRU (16 pilot tones): "Tone 1, tone 69, tone 135, tone 203, tone 249, tone 317, tone 383, tone 451, tone 482, tone 550, tone 616, tone 684, tone 730, tone 798, tone 864 and tone 93..." "2 tones" or "65th tone, 133rd tone, 199th tone, 267th tone, 313th tone, 381st tone, 447th tone, 515th tone, 546th tone, 614th tone, 680th tone, 748th tone, 794th tone, 862nd tone, 928th tone, 996th tone"

[0210] Examples 1-3

[0211] Examples 1-3 relate to a method of setting the first or last tone in the frequency domain as a pilot tone and then setting the pilot tone at regular intervals. When applying Examples 1-3, it may be advantageous from a performance perspective because the pilot tone and data tone are evenly distributed.

[0212] In other words, considering cyclic shifting, a certain number of data tones can be positioned between pilot tones, and this certain number of data tones can be "(DRU size - number of pilot tones) / number of pilot tones", "floor{(DRU size - number of pilot tones) / number of pilot tones}", or "ceil{(DRU size - number of pilot tones) / number of pilot tones}". Here, "floor(a)" refers to a function that returns an integer value by lowering the decimal point when a has a decimal point. "ceil(a)" refers to a function that returns an integer value by raising the decimal point when a has a decimal point.

[0213] Considering cyclic shift, the fact that a certain number of data tones lie between pilot tones may mean that, considering cyclic shift, not only the number of data tones between each pilot tone but also the sum of the number of data tones after the last pilot tone and before the first pilot tone is a certain number. In the following text, considering cyclic shift, data tone may refer to the data tone located between the last pilot tone and the first pilot tone.

[0214] For example, suppose an RU consisting of 10 tones includes 2 pilot tones, and the first tone of the 10 tones is a pilot tone. After the pilot tone is set to the first tone, 4 data tones are set, and the pilot tone can be positioned as the sixth tone. After the pilot tone is set to the sixth tone, 4 data tones can be positioned.

[0215] The following describes the location of the pilot tone and data tone according to the DRU type.

[0216] -26 DRU (2 pilot tones): 12 data tones can be located between pilot tones, and the initial pilot tones can be "the 1st tone and the 14th tone" or "the 13th tone and the 26th tone".

[0217] - 52 DRU (4 pilot tones): There can be 12 data tones between pilot tones, and the initial pilot tones can be "the 1st tone, the 14th tone, the 27th tone and the 40th tone" or "the 13th tone, the 26th tone, the 39th tone and the 52nd tone".

[0218] -106 DRU (number of pilot tones is 4): 25 or 26 data tones can be located between pilot tones. 25 or 26 data tones can exist between pilot tones in various positions. For example, if "25+1 = a" and "26+1 = b" are defined, the first pilot tone can be set / defined as one of the following example combinations.

[0219] -- The first pitch, the first + a pitch, the first + 2a pitch, the first + 2a + b pitch, and the combination of (a, a, b).

[0220] -- The first pitch, the first + a pitch, the first + a + b pitch, the first + 2a + b pitch, and the combination of (a, b, a).

[0221] -- The first tone, the 1+a tone, the 1+a+b tone, the 1+a+2b tone, and the combination of (a, b, b).

[0222] -- The first tone, the 1+bth tone, the 1+a+bth tone, the 1+2a+bth tone, and the combination of (b, a, a).

[0223] -- The first tone, the 1+bth tone, the 1+a+bth tone, the 1+a+2bth tone, and the combination of (b, a, b).

[0224] -- The first pitch, the 1+b pitch, the 1+2b pitch, the 1+a+2b pitch, and the combination of (b, b, a).

[0225] -- The 106-2a-b tone, the 106-ab tone, the 106-b tone, the 106th tone, and the combination (a, a,b).

[0226] -- The 106-2a-b tone, the 106-ab tone, the 106-a tone, the 106th tone, and the combination (a, b, a).

[0227] -- The 106-a-2bth tone, the 106-2bth tone, the 106-bth tone, the 106th tone, and the combination of (a, b, b).

[0228] -- The 106-2a-b tone, the 106-2a tone, the 106-a tone, the 106th tone, and the combination (b, a, a).

[0229] The 106-a-2b tone, the 106-ab tone, the 106-b tone, the 106th tone, and the combination of (b, a, b).

[0230] The 106-a-2b tone, the 106-ab tone, the 106-a tone, the 106th tone, and the combination (b, b, a).

[0231] The combination of (x, y, z) could mean that there are x data tones between the first and second pilot tones, y data tones between the second and third pilot tones, and z data tones between the third and fourth pilot tones.

[0232] In other words, if the pilot tone is located at the first tone and the combination (x, y, z) is set, the position of the second pilot tone can be calculated by adding 1 to x, the position of the third pilot tone can be calculated by adding 1 to y and x, and the position of the fourth pilot tone can be calculated by adding 1 to z and x and y.

[0233] In 242 / 484 / 996 DRUs, combinations of 7 / 15 / 15 numbers can be considered instead of the 3-number combinations mentioned above. The position of the next pilot tone can be derived by summing the number of data tones between pilot tones, as in 106 DRUs.

[0234] For example, if the pilot tone is located at the last tone, considering the combination (x, y, z), the position of the third pilot tone can be calculated by subtracting z from the index of the last tone. The position of the second pilot tone can be calculated by subtracting y from the position of the third pilot tone. The position of the first pilot tone can be calculated by subtracting x from the position of the third pilot tone.

[0235] In the 242 / 484 / 996 DRU, combinations of 7 / 15 / 15 numbers can be considered instead of the 3-number combinations mentioned above. The position of the next pilot tone can be derived by subtracting the number of data tones between pilot tones from the position of the last pilot tone.

[0236] - 242 DRU (8 pilot tones): 29 or 30 data tones can be positioned between pilot tones. 29 or 30 data tones can exist between pilot tones at various locations. For example, if we define "29+1 = a" and "30+1 = b", the first pilot tone can be set / defined by applying one of the following example combinations.

[0237] - (a, a, a, a, a, a, b), (a, a, a, a, a, b, a), (a, a, a, a, b, a, a), (a, a, a, b, a, a, a), (a, a, b, a, a, a, a), (a, b, a, a, a, a, a), (b, a, a,a, a, a, a), (a, a, a, a, a, b, b), (a, a, a, a, b, a, b), (a, a, a, b, a, a,b), (a, a, b, a, a, a, b), (a, b, a, a, a, a, b), (b, a, a, a, a, a, b), (a, a,a, a, b, b, a), (a, a, a, b, a, b, a), (a, a, b, a, a, b, a), (a, b, a, a, a, b,a), (b, a, a, a, a, b, a), (a, a, a, b, b, a, a), (a, a, b, a, b, a, a), (a, b,a, a, b, a, a), (b, a, a, a, b, a, a), (a, a, b, b, a, a, a), (a, b, a, b, a, a,a), (b, a, a, b, a, a, a), (a, b, b, a, a, a, a), (b, a, b, a, a, a, a), (b, b,a, a, a, a, a)

[0238] For example, if the combination (a, a, a, a, a, a, b) is applied, this might mean that the 1st tone, the 1+ath tone, the 1+2ath tone, the 1+3ath tone, the 1+4ath tone, the 1+5ath tone, the 1+6ath tone, and the 1+6a+bth tone are set / defined as pilot tones. Furthermore, between each of the pilot tones, data tones a, a, a, a, a, a, a, a, and b can be set / defined.

[0239] - 484 DRU (16 pilot tones): 29 or 30 data tones can be located between pilot tones. The 29 or 30 data tones can be located at 12 positions and 4 positions respectively. For example, if "29+1 = a" and "30+1 = b" are defined, the first pilot tone can be applied in various combinations of 12 a's and 3 b's or 11 a's and 4 b's.

[0240] - 996 DRU (16 pilot tones): 61 or 62 data tones can be located between pilot tones. The 61 or 62 data tones can be located at 12 positions and 4 positions respectively. For example, if "61+1 = a" and "62+1 = b" are defined, the first pilot tone can be applied in various combinations of 12 a's and 3 b's or 11 a's and 4 b's.

[0241] Example 2

[0242] Example 2 relates to a method in which the position of the pilot tone is changed by a specific cyclic shift rule starting from a symbol following the symbol to which the first pilot tone is applied according to Examples 1, 1-1, 1-2, and 1-3. Here, the symbol to which the first pilot tone is applied may include: i) the first symbol of the UHR-LTF field; or ii) the entire symbol of the UHR-LTF field and the first symbol of the data portion.

[0243] Example 2-1

[0244] Example 2-1 relates to a method of applying cyclic shifts at equal intervals to each symbol. In this case, the cyclic shifts can be fixed in the rightward or leftward direction.

[0245] The interval for applying the cyclic shift can be set / determined / defined as a value less than the minimum interval between pilot tones. For example, in the case of 996 DRUs, the minimum interval between pilot tones can be determined / set to 61 or 62.

[0246] As another example, the interval for applying the cyclic shift can be determined / set to be less than the minimum value among the intervals between pilot tones divided by 2. For example, the interval for applying the cyclic shift can be 1, but is not limited to this.

[0247] Because a cyclic shift value is applied as a constant value to each symbol, the implementation can be straightforward.

[0248] Example 2-2

[0249] Example 2-2 relates to a method for applying different cyclic shift values ​​to each symbol. In this case, the cyclic shift value applied to each symbol can be fixed in the rightward or leftward direction, but is not limited thereto. The cyclic shift value applied to each symbol can be determined as a rightward value for a specific symbol, but can be determined as a leftward value for other symbols. The cyclic shift value can be equal to the symbol index or can be set to "symbol index + 1".

[0250] As another example, the first value of the cyclic shift (i.e., the interval at which the first cyclic shift value is applied to the sign) can be 1, and the second value can be incremented by 'a' sequentially based on the first value. That is, the second value can be 1+a, and the third value can be 1+2a. In this case, 'a' can be a specific natural number (e.g., 1, etc.).

[0251] As another example, the first value of the cyclic shift (i.e., the cyclic shift value first applied to the symbol) can be 1, and starting with the second value (i.e., the cyclic shift value applied to the second symbol), it can be sequentially increased by 'a' based on the first value. Then, when the cyclic shift value at a specific point in time is increased by 'a', if it reaches a minimum value or a specific value within the interval between pilot tones, the cyclic shift value can be sequentially decreased by 'a'. Then, when the cyclic shift value is decreased by 'a' and reaches 1, the cyclic shift value can again be sequentially increased by 'a'.

[0252] As another example, the cyclic shift value can be set by applying a modulo operation value (e.g., (mod(a, b) = a modulo b)). For example, the cyclic shift value can be set to "mod(symbol index, minimum interval between pilots - 1) + 1" or "mod(symbol index + 1, minimum interval between pilots - 1) + 1".

[0253] According to the above embodiments, the position of the pilot tone can be changed for each symbol, and thus the traveling pilot that can obtain frequency diversity benefits in residual CFO measurements can be applied to the DRU.

[0254] Figure 14This is a diagram illustrating the PPDU transmission and reception process between a transmitting STA and a receiving STA according to an embodiment of this disclosure. Depending on the circumstances and / or settings, this may be omitted. Figure 14 Some of the steps shown. The transmitting device and the receiving STA can be an AP and / or a non-AP STA.

[0255] Sending a STA can obtain control information related to the aforementioned tone plan (or RU / DRU) (S105). The control information related to the tone plan may include information on the size and location of the RU, control information related to the RU, information on the frequency band in which the RU is included, and information on the STA receiving the RU.

[0256] The STA can construct / generate a PPDU based on the acquired control information (S110). Constructing / generating a PPDU can mean constructing / generating each field of the PPDU. That is, the step of constructing / generating a PPDU may include the step of constructing / configuring the EHT-SIG-A / B / C fields, which include control information for tone planning.

[0257] In other words, the steps of constructing / generating a PPDU may include constructing / configuring a field that includes control information (e.g., an N-bitmap) indicating the size / location of the RU and / or constructing / configuring a field that includes an identifier (e.g., an AID) of the STA receiving the RU.

[0258] Additionally, the steps of constructing / generating a PPDU may include generating an STF / LTF sequence transmitted via a specific RU. The STF / LTF sequence can be generated based on a pre-configured STF generation sequence / LTF generation sequence.

[0259] Additionally, the steps of constructing / generating a PPDU may include generating a data field (i.e., an MPDU) that is sent through a specific RU.

[0260] The sending STA can send the constructed / generated PPDU to the receiving STA (S115).

[0261] Specifically, the STA can perform at least one of the following operations: cyclic shift diversity (CSD), spatial mapping, inverse discrete Fourier transform (IDFT) / inverse fast Fourier transform (IFFT) operation, and guard interval (GI) insertion operation.

[0262] The receiving STA can decode the PPDU and obtain control information related to the tone plan (or RU) (S120).

[0263] Specifically, the receiving STA can decode the L-SIG and EHT-SIG of the PPDU based on L-STF / LTF and obtain the information included in the L-SIG and EHT-SIG fields. Information for various tone schemes (i.e., RUs) used in this disclosure can be included in the EHT-SIG (EHT-SIG-A / B / C, etc.), and the receiving STA can obtain the information for tone schemes (i.e., RUs) through the EHT-SIG.

[0264] The receiving STA can decode the remaining part of the PPDU based on the acquired tone plan (i.e., RU) information (S125). For example, the receiving STA can decode the STF / LTF field of the PPDU based on the tone plan (i.e., RU) information. In addition, the receiving STA can decode the data field of the PPDU based on the tone plan (i.e., RU) information and acquire the MPDU included in the data field.

[0265] The receiving STA can also perform processing operations to deliver decoded data to higher layers (e.g., the MAC layer). Additionally, when an indication signal is generated from a higher layer to the PHY layer in response to data being delivered to a higher layer, the receiving STA can perform subsequent operations.

[0266] The above embodiments combine the elements and features of this disclosure in a predetermined form. Unless otherwise expressly stated, each element or feature should be considered optional. Each element or feature can be implemented without combination with other elements or features. Furthermore, embodiments of this disclosure may include combinations of certain elements and / or features. The order of operations described in the embodiments of this disclosure may be changed. Some elements or features of one embodiment may be included in other embodiments, or may be replaced by corresponding elements or features of other embodiments. It is clear that embodiments may include combinations of claims where there is no explicit dependency in the claims, or may be included as new claims by amendment after the application.

[0267] It will be apparent to those skilled in the art that this disclosure may be practiced in other specific forms without departing from the essential characteristics of this disclosure. Therefore, the foregoing detailed description should not be construed as restrictive in every respect, but rather as illustrative. The scope of the invention should be determined by a reasonable interpretation of the appended claims, and all variations within the equivalent scope of this disclosure are included within the scope of the invention.

[0268] The scope of this disclosure includes software or machine-executable commands (e.g., operating systems, applications, firmware, programs, etc.) that operate in a device or computer according to methods of various embodiments, and non-transitory computer-readable media that store such software or commands and can be executed in a device or computer. Commands that can be used to program a processing system to perform the features described in this disclosure can be stored in a storage medium or a computer-readable storage medium, and the features described in this disclosure can be implemented using a computer program product including such a 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 storage devices, and may include non-volatile memory, such as one or more disk storage devices, optical disk storage devices, flash memory devices, or other non-volatile solid-state storage devices. The memory may optionally include one or more storage devices located remote from the processor. Alternatively, the non-volatile memory devices in the memory may include non-transitory computer-readable storage media. The features described in this disclosure can be stored in any machine-readable medium to control the hardware of a processing system and can be integrated into software and / or firmware that allows the processing system to interact with other mechanisms using results from embodiments of this disclosure. Such software or firmware may include, but is not limited to, application code, device drivers, operating systems, and execution environments / containers.

[0269] [Industrial Applicability]

[0270] The method proposed in this disclosure is described primarily based on examples applied to IEEE 802.11-based systems, but it can also be applied to various WLAN or wireless communication systems other than IEEE 802.11-based systems.

Claims

1. A method performed by a first station (STA) in a wireless local area network (WLAN) system, the method comprising: A physical layer protocol data unit (PPDU) comprising multiple symbol groups is generated, and the multiple symbol groups are mapped to at least one distributed resource unit (DRU). as well as The PPDU is sent to at least one second STA within the bandwidth. The plurality of symbol groups includes a first symbol group and a second symbol group following the first symbol group. In this process, at least one first pilot tone, corresponding to a position in the first symbol group, is used among a plurality of pilot tones in a predefined resource unit associated with the bandwidth. The index of each of the plurality of second pilot tones used in each of the plurality of symbols included in the second symbol group is based on a cyclic shift value applied to each of the plurality of symbols included in the second symbol group.

2. The method according to claim 1, wherein: The first symbol group includes all symbols of the Ultra-High Reliability Long Training Field (UHR-LTF) of the PPDU and the first symbol of the data portion.

3. The method according to claim 1, wherein: Based on the fact that the at least one DRU is a 26-tone DRU, the at least one first pilot tone is one of {the 6th tone of the 26-tone DRU, the 20th tone of the 26-tone DRU}, {the 7th tone of the 26-tone DRU, the 21st tone of the 26-tone DRU}, or {the 7th tone of the 26-tone DRU, the 20th tone of the 26-tone DRU}.

4. The method according to claim 1, wherein: Based on the fact that the at least one DRU is a 52-tone DRU, the at least one first pilot tone is one of {the 6th tone of the 52-tone DRU, the 20th tone of the 52-tone DRU, the 32nd tone of the 52-tone DRU, the 46th tone of the 52-tone DRU} or {the 7th tone of the 52-tone DRU, the 22nd tone of the 52-tone DRU, the 33rd tone of the 52-tone DRU, the 47th tone of the 52-tone DRU}.

5. The method according to claim 1, wherein: Based on the fact that the at least one DRU is a 106-tone DRU, the at least one first pilot tone is one of {the 7th tone of the 106-tone DRU, the 33rd tone of the 106-tone DRU, the 75th tone of the 106-tone DRU, the 101st tone of the 106-tone DRU} or {the 6th tone of the 106-tone DRU, the 32nd tone of the 106-tone DRU, the 74th tone of the 106-tone DRU, the 100th tone of the 106-tone DRU}.

6. The method according to claim 1, wherein: Based on the fact that the at least one DRU is a 242-tone DRU, the at least one first pilot tone is {the 7th tone of the 242-tone DRU, the 33rd tone of the 242-tone DRU, the 75th tone of the 242-tone DRU, the 101st tone of the 242-tone DRU, the 141st tone of the 242-tone DRU, the 167th tone of the 242-tone DRU, the 209th tone of the 242-tone DRU, the 2 The 235th tone of the 42-tone DRU or the 8th tone of the 242-tone DRU, the 34th tone of the 242-tone DRU, the 76th tone of the 242-tone DRU, the 102nd tone of the 242-tone DRU, the 142nd tone of the 242-tone DRU, the 168th tone of the 242-tone DRU, the 210th tone of the 242-tone DRU, and the 236th tone of the 242-tone DRU.

7. The method according to claim 1, wherein: Based on the fact that the at least one DRU is a 484-tone DRU, the at least one first pilot tone is {the 7th tone of the 484-tone DRU, the 33rd tone of the 484-tone DRU, the 75th tone of the 484-tone DRU, the 101st tone of the 484-tone DRU, the 141st tone of the 484-tone DRU, the 167th tone of the 484-tone DRU, the 209th tone of the 484-tone DRU, the 48...} The 235th tone of the 4-tone DRU, the 250th tone of the 484-tone DRU, the 276th tone of the 484-tone DRU, the 318th tone of the 484-tone DRU, the 344th tone of the 484-tone DRU, the 384th tone of the 484-tone DRU, the 410th tone of the 484-tone DRU, the 452nd tone of the 484-tone DRU, and the 478th tone of the 484-tone DRU.

8. The method according to claim 1, wherein: Based on the fact that the at least one DRU is a 996-tone DRU, the at least one first pilot tone is {the 33rd tone of the 996-tone DRU, the 101st tone of the 996-tone DRU, the 167th tone of the 996-tone DRU, the 235th tone of the 996-tone DRU, the 281st tone of the 996-tone DRU, the 349th tone of the 996-tone DRU, the 415th tone of the 996-tone DRU, ... The 483rd tone of the 96-tone DRU, the 514th tone of the 996-tone DRU, the 582nd tone of the 996-tone DRU, the 648th tone of the 996-tone DRU, the 716th tone of the 996-tone DRU, the 762nd tone of the 996-tone DRU, the 830th tone of the 996-tone DRU, the 896th tone of the 996-tone DRU, and the 964th tone of the 996-tone DRU.

9. The method according to claim 1, wherein: The cyclic shift value applied to each of the plurality of symbols included in the second symbol group is set to a value smaller than the minimum value among the intervals between the at least one first pilot tone.

10. The method according to claim 1, wherein: The cyclic shift value applied to the nth symbol (n is a natural number greater than or equal to 1) among the plurality of symbols included in the second symbol group is x (x is a natural number greater than or equal to 1), and The cyclic shift value applied to the (n+1)th symbol among the plurality of symbols included in the second symbol group is "x±a" (where a is a natural number greater than or equal to 1).

11. The method according to claim 1, wherein: The cyclic shift value applied to the nth symbol among the plurality of symbols included in the second symbol group is "mod(index of the nth symbol, minimum value among the intervals between the at least one first pilot - 1) + 1" or "mod(index of the nth symbol + 1, minimum value among the intervals between the at least one first pilot - 1) + 1".

12. A first station (STA) device in a wireless local area network (WLAN) system, the first STA comprising: At least one transceiver; as well as At least one processor is connected to the at least one transceiver. Wherein, the at least one processor is configured to: Generate Physical Layer Protocol Data Units (PPDUs) comprising multiple symbol groups, wherein the multiple symbol groups are mapped to at least one Distributed Resource Unit (DRU); and The PPDU is transmitted to at least one second STA within the bandwidth via the at least one transceiver. The plurality of symbol groups includes a first symbol group and a second symbol group following the first symbol group. In this process, at least one first pilot tone, corresponding to a position in the first symbol group, is used among a plurality of pilot tones in a predefined resource unit associated with the bandwidth. The index of each of the plurality of second pilot tones used in each of the plurality of symbols included in the second symbol group is based on a cyclic shift value applied to each of the plurality of symbols included in the second symbol group.

13. A method performed by a second station (STA) in a wireless LAN system, the method comprising: Physical layer protocol data units (PPDUs) comprising multiple symbol groups are received from the first STA via bandwidth, and the multiple symbol groups are mapped to at least one distributed resource unit (DRU). as well as Decode the PPDU, The plurality of symbol groups includes a first symbol group and a second symbol group following the first symbol group. In this process, at least one first pilot tone, corresponding to a position in the first symbol group, is used among a plurality of pilot tones in a predefined resource unit associated with the bandwidth. The index of each of the plurality of second pilot tones used in each of the plurality of symbols included in the second symbol group is based on a cyclic shift value applied to each of the plurality of symbols included in the second symbol group.

14. A second station (STA) operating in a wireless LAN system, the second STA comprising: At least one transceiver; as well as At least one processor is connected to the at least one transceiver. Wherein, the at least one processor is configured to: Through the at least one transceiver, Physical Layer Protocol Data Units (PPDUs) comprising multiple symbol groups are received from the first STA via bandwidth, the multiple symbol groups being mapped to at least one Distributed Resource Unit (DRU); and Decode the PPDU, The plurality of symbol groups includes a first symbol group and a second symbol group following the first symbol group. In this process, at least one first pilot tone, corresponding to a position in the first symbol group, is used among a plurality of pilot tones in a predefined resource unit associated with the bandwidth. The index of each of the plurality of second pilot tones used in each of the plurality of symbols included in the second symbol group is based on a cyclic shift value applied to each of the plurality of symbols included in the second symbol group.

15. A processing device configured to control a station (STA) in a wireless local area network (WLAN) system, the processing device comprising: At least one processor; as well as At least one computer memory, operatively connected to the one or more processors and storing instructions that, when executed by the at least one processor, perform the method according to any one of claims 1 to 11.

16. At least one non-transitory computer-readable medium, said at least one non-transitory computer-readable medium storing one or more commands, in, The one or more commands are executed by one or more processors to control devices in the wireless LAN system to perform the method according to any one of claims 1 to 11.

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