Method and device for defining pilot tone for interference mitigation during 40 mhz transmission in wireless LAN system

Abstract

A method and device for defining a pilot tone for interference mitigation during 40 MHz transmission in a wireless LAN system are proposed. Specifically, a non-AP STA receives a PPDU from an AP and decodes same. The PPDU includes a data field. The data field includes an IM pilot having zero energy. On the basis that a bandwidth of the PPDU is 40 MHz, the IM pilot is inserted at intervals of nine subcarrier indices from a first subcarrier index to a second subcarrier index, and is inserted at intervals of nine indices from a third subcarrier index to a fourth subcarrier index. The first subcarrier index is -240, the second subcarrier index is -6, the third subcarrier index is 6, and the fourth subcarrier index is 240.

Description

Method and apparatus for defining a pilot tone for interference mitigation during 40 MHz transmission in a wireless LAN system

[0001] The present specification relates to an Interference Mitigation (IM) pilot tone plan in a wireless LAN system, and more specifically, to a method and apparatus for defining an IM pilot that enables a receiving STA to measure and mitigate interference when transmitting in a 40 MHz frequency band to increase reception reliability in UHR or next wi-fi.

[0002] Next-generation Wi-Fi (e.g., IEEE 802.11be and / or later) aims to support ultra-high reliability when transmitting signals to STAs, and to this end, various technologies are being considered to support high throughput, low latency, and extended range. For example, a procedure to insert an IM pilot to measure and mitigate interference can be performed.

[0003] This specification proposes a method and apparatus for defining a pilot tone for interference mitigation during 40MHz transmission in a wireless LAN system.

[0004] One example of the present specification proposes a method for defining an IM pilot capable of measuring and mitigating interference during transmission in a 40 MHz frequency bandwidth.

[0005] This embodiment can be performed in a network environment that supports a next-generation wireless LAN system (UHR (Ultra High Reliability) wireless LAN system or next wi-fi). The next-generation wireless LAN system is a wireless LAN system that improves upon the 802.11be system and can satisfy backward compatibility with the 802.11be system.

[0006] This embodiment can be performed at a non-AP STA (non-access point station). The non-AP STA can be replaced with a non-AP MLD (non-access point Multi-link Device). The AP (access point) of this embodiment can be replaced with an AP MLD.

[0007] This embodiment proposes a method for defining an IM (Interference Mitigation) pilot capable of measuring and mitigating interference during transmission in a 40 MHz frequency band to increase reception reliability in a wireless LAN system. Specifically, it defines a method for determining the location of an IM pilot using an index so that the IM pilot does not overlap with existing pilots transmitted for Carrier Frequency Offset (CFO) tracking and compensation.

[0008] A non-AP STA (non-access point station) receives a PPDU (Physical Protocol Data Unit) from an AP (access point).

[0009] The above non-AP STA decodes the above PPDU.

[0010] The above PPDU includes a data field.

[0011] The above data field includes an IM (Interference Mitigation) pilot having 0 energy.

[0012] Based on the fact that the bandwidth of the above PPDU is 40 MHz, the above IM pilot,

[0013] It is inserted at intervals of 9 indices from the first subcarrier index to the second subcarrier index, and at intervals of 9 indices from the third subcarrier index to the fourth subcarrier index.

[0014] The first subcarrier index may be -240, the second subcarrier index may be -6, the third subcarrier index may be 6, and the fourth subcarrier index may be 240. For example, the index of the subcarrier into which the IM pilot is inserted may be represented as [-240:9:-6], [6:9:240], etc. That is, when many IM pilots are defined and inserted, the pilot overhead increases, which reduces the number of subcarriers for data transmission. To compensate for this, when considering the IM pilot overhead as 10~11%, IM pilots can be defined at intervals of 9 subcarrier units. By arranging IM pilots at intervals of 9 subcarriers and limiting the number of IM pilots to a certain range, the number of subcarriers for data transmission is secured, thereby ensuring the throughput of data transmission. Additionally, the subcarrier placement of the above IM pilot is positioned at a certain distance from the guard subcarrier and DC (Direct Current) subcarrier, which has the effect of reducing the influence of the guard subcarrier and DC subcarrier.

[0015] For example, the above IM pilot can be deployed based on a negative subcarrier index and a positive subcarrier index that form mirror symmetry.

[0016] At this time, the positive subcarrier index may be configured to have the same absolute value as the negative subcarrier index and the opposite sign.

[0017] In other words, when the IM pilot does not form mirror symmetry, implementation is easy because the IM pilot is defined using fixed subcarrier positions in units of 9 subcarriers; however, there is a disadvantage that interference measurements may be inaccurate when transmitted at low or high frequencies because the spacing between the IM pilot subcarriers from the left guard subcarrier and the right guard subcarrier differs. Therefore, the IM pilot can be placed at negative and positive subcarrier indices that form mirror symmetry with respect to the DC (Direct Current), and as a result, the spacing between the IM pilot subcarriers from the left guard subcarrier and the right guard subcarrier becomes the same, allowing for more accurate interference measurements.

[0018] Previously, signal transmission and reception performance was degraded due to interference caused by the OBSS (Overlapping Basic Service Set) and AP density. However, according to the method proposed in this embodiment, signal transmission and reception performance can be improved by including an IM pilot during 40 MHz PPDU transmission and reception to measure and mitigate the effects of interference.

[0019] FIG. 1 shows an example of a transmitting device and / or receiving device of the present specification.

[0020] Figure 2 is a conceptual diagram showing the structure of a wireless LAN (WLAN).

[0021] Figure 3 is a diagram illustrating a general link setup process.

[0022] FIG. 4 illustrates an example of a multi-link (ML).

[0023] FIG. 5 illustrates a PPDU (physical protocol data unit or physical layer (PHY) protocol data unit) transmitted / received in an STA of the present specification.

[0024] Figure 6 is a diagram showing the arrangement of resource units (RU) used for a 20 MHz PPDU.

[0025] Figure 7 is a diagram showing the arrangement of resource units (RU) used for a 40 MHz PPDU.

[0026] Figure 8 is a diagram showing the arrangement of resource units (RU) used for an 80 MHz PPDU.

[0027] Figure 9 shows the operation according to UL-MU.

[0028] Figure 10 shows an example of a channel used / supported / defined within the 2.4 GHz band.

[0029] FIG. 11 illustrates an example of a channel used / supported / defined within the 5 GHz band.

[0030] FIG. 12 illustrates an example of a channel used / supported / defined within the 6 GHz band.

[0031] Figure 13 shows an example of a MAC frame header.

[0032] FIG. 14 shows a modified example of a transmitting device and / or receiving device of the present specification.

[0033] Figure 15 shows an example of an IM pilot being inserted.

[0034] FIG. 16 is a flowchart illustrating the operation of a transmitting device according to the present embodiment.

[0035] FIG. 17 is a flowchart illustrating the operation of a receiving device according to the present embodiment.

[0036] FIG. 18 is a flowchart illustrating the procedure for a non-AP STA to receive a PPDU according to the present embodiment.

[0037] FIG. 19 is a flowchart illustrating the procedure for an AP to transmit a PPDU according to the present embodiment.

[0038] In this specification, “A or B” may mean “only A,” “only B,” or “both A and B.” Alternatively, in this specification, “A or B” may be interpreted as “A and / or B.” For example, in this specification, “A, B or C” may mean “only A,” “only B,” “only C,” or “any combination of A, B and C.”

[0039] As used herein, a slash ( / ) or a comma may mean “and / or.” For example, “A / B” may mean “A and / or B.” Accordingly, “A / B” may mean “only A,” “only B,” or “both A and B.” For example, “A, B, C” may mean “A, B, or C.”

[0040] In this specification, “at least one of A and B” may mean “only A,” “only B,” or “both A and B.” Additionally, in this specification, the expressions “at least one of A or B” or “at least one of A and / or B” may be interpreted as synonymous with “at least one of A and B.”

[0041] Additionally, parentheses used in this specification may mean “for example.” Specifically, when indicated as “control information (UHR-Signal field),” the “UHR-Signal field” may be proposed as an example of “control information.” In other words, the “control information” of this specification is not limited to the “UHR-Signal field,” and the “UHR-Signal field” may be proposed as an example of “control information.” Furthermore, even when indicated as “control information (UHR-Signal field),” the “UHR-Signal field” may be proposed as an example of “control information.”

[0042] Additionally, as used herein, “a / an” may mean “at least one” or “one or more.” Also, terms ending in “(s)” may mean “at least one” or “one or more.”

[0043] Additionally, the expressions “based on,” “on the basis of,” or “according to” as used herein mean “based at least in part on,” and do not mean “based only on one.”

[0044] Technical features described individually within a single drawing in this specification may be implemented individually or simultaneously.

[0045] The following examples of this specification may be applied to various wireless communication systems. For example, the following examples of this specification may be applied to wireless local area network (WLAN) systems. For example, this specification may be applied to IEEE 802.11a / g / n / ac / ax / be / bn standards. In addition, the examples of this specification may be applied to Ultra High Reliability (UHR) standards or next-generation wireless LAN standards that enhance IEEE 802.11bn. In addition, the examples of this specification may be applied to mobile communication systems. For example, they may be applied to mobile communication systems based on Long Term Evolution (LTE) and its evolution based on 3GPP (3rd Generation Partnership Project) standards.

[0046] To explain the technical features of this specification, the technical features to which this specification can be applied are described below.

[0047] FIG. 1 shows an example of a transmitting device and / or receiving device of the present specification.

[0048] An example of FIG. 1 can perform various technical features described below. FIG. 1 relates to at least one STA (station). For example, the STA (110, 120) of this specification may also be referred to by various names such as mobile terminal, wireless device, Wireless Transmit / Receive Unit (WTRU), User Equipment (UE), Mobile Station (MS), Mobile Subscriber Unit, or simply user. The STA (110, 120) of this specification may also be referred to by various names such as network, base station, Node-B, Access Point (AP), repeater, router, relay, etc. The STA (110, 120) of this specification may also be referred to by various names such as receiving apparatus, transmitting device, receiving STA, transmitting STA, receiving device, transmitting device, etc.

[0049] For example, the STA (110, 120) can perform the role of an access point (AP) or a non-AP. That is, the STA (110, 120) of this specification can perform the functions of an AP and / or a non-AP. In this specification, an AP may also be indicated as an AP STA.

[0050] The STA (110, 120) of this specification may support various communication standards other than the IEEE 802.11 standard. For example, it may support communication standards according to 3GPP standards (e.g., LTE, LTE-A, 5G NR standards). In addition, the STA of this specification may be implemented in various devices such as mobile phones, vehicles, and personal computers. Furthermore, the STA of this specification may support communication for various communication services such as voice calls, video calls, data communication, and self-driving.

[0051] In this specification, the STA (110, 120) may include a medium access control (MAC) that complies with the provisions of the IEEE 802.11 standard and a physical layer interface for the wireless medium.

[0052] Based on side drawing (a) of Fig. 1, STA (110, 120) is described as follows.

[0053] The first STA (110) may include a processor (111), memory (112), and a transceiver (113). The illustrated processor, memory, and transceiver may each be implemented as separate chips, or at least two blocks / functions may be implemented through a single chip.

[0054] The transceiver (113) of the first STA performs the operation of transmitting and receiving signals. Specifically, it can transmit and receive IEEE 802.11 packets (e.g., IEEE 802.11a / b / g / n / ac / ax / be, etc.).

[0055] For example, the first STA (110) can perform the intended operation of the AP. For example, the processor (111) of the AP can receive a signal through the transceiver (113), process the received signal, generate a transmitted signal, and perform control for transmitting the signal. The memory (112) of the AP can store the signal received through the transceiver (113) (i.e., the received signal) and the signal to be transmitted through the transceiver (i.e., the transmitted signal).

[0056] For example, the second STA (120) can perform the intended operation of a Non-AP STA. For example, the non-AP transceiver (123) performs the operation of transmitting and receiving signals. Specifically, it can transmit and receive IEEE 802.11 packets (e.g., IEEE 802.11a / b / g / n / ac / ax / be, etc.).

[0057] For example, the processor (121) of the Non-AP STA can receive a signal through the transceiver (123), process the received signal, generate a transmitted signal, and perform control for transmitting the signal. The memory (122) of the Non-AP STA can store the signal received through the transceiver (123) (i.e., the received signal) and can store the signal to be transmitted through the transceiver (i.e., the transmitted signal).

[0058] For example, the operation of the device indicated as AP in the following specification may be performed in the first STA (110) or the second STA (120). For example, if the first STA (110) is the AP, the operation of the device indicated as AP is controlled by the processor (111) of the first STA (110), and related signals may be transmitted or received through a transceiver (113) controlled by the processor (111) of the first STA (110). Additionally, control information related to the operation of the AP or the transmission / reception signals of the AP may be stored in the memory (112) of the first STA (110). Additionally, if the second STA (110) is the AP, the operation of the device indicated as AP is controlled by the processor (121) of the second STA (120), and related signals may be transmitted or received through a transceiver (123) controlled by the processor (121) of the second STA (120). In addition, control information related to the operation of the AP or the transmission / reception signals of the AP can be stored in the memory (122) of the second STA (110).

[0059] For example, the operation of a device indicated as non-AP (or User-STA) in the following specification may be performed in the STA (110) or the second STA (120). For example, if the second STA (120) is non-AP, the operation of the device indicated as non-AP is controlled by the processor (121) of the second STA (120), and related signals may be transmitted or received through a transceiver (123) controlled by the processor (121) of the second STA (120). Additionally, control information related to the operation of the non-AP or the transmission / reception signals of the AP may be stored in the memory (122) of the second STA (120). For example, if the first STA (110) is a non-AP, the operation of the device marked as non-AP is controlled by the processor (111) of the first STA (110), and the related signal can be transmitted or received through a transceiver (113) controlled by the processor (111) of the first STA (120). Additionally, control information related to the operation of the non-AP or the transmission / reception signal of the AP can be stored in the memory (112) of the first STA (110).

[0060] In the following specification, a device referred to as (transmission / reception) STA, first STA, second STA, STA1, STA2, AP, first AP, second AP, AP1, AP2, (transmission / reception) Terminal, (transmission / reception) device, (transmission / reception) apparatus, network, etc. may refer to the STA (110, 120) of FIG. 1. For example, a device indicated without specific drawing symbols as (transmission / reception) STA, first STA, second STA, STA1, STA2, AP, first AP, second AP, AP1, AP2, (transmission / reception) Terminal, (transmission / reception) device, (transmission / reception) apparatus, network, etc. may also refer to the STA (110, 120) of FIG. 1. For example, in the following example, the operation of various STAs transmitting and receiving signals (e.g., PPPDU) may be performed by the transceiver (113, 123) of FIG. 1. Additionally, in the following example, the operation of various STAs generating transmission and reception signals or performing data processing or calculations in advance for transmission and reception signals may be performed by the processor (111, 121) of FIG. 1.For example, an example of an operation to generate a transmission / reception signal or to perform data processing or operations in advance for a transmission / reception signal may include: 1) an operation to determine / acquire / configure / operate / decode / encode bit information of sub-fields (SIG, STF, LTF, Data) included in the PPDU; 2) an operation to determine / configure / acquire time resources or frequency resources (e.g., subcarrier resources) used for sub-fields (SIG, STF, LTF, Data) included in the PPDU; 3) an operation to determine / configure / acquire specific sequences (e.g., pilot sequence, STF / LTF sequence, extra sequence applied to SIG) used for sub-fields (SIG, STF, LTF, Data) included in the PPDU; 4) a power control operation and / or power saving operation applied to the STA; and 5) an operation related to determining / acquiring / configuring / operating / decoding / encoding of an ACK signal. In addition, in the following example, various information (e.g., information related to fields, subfields, control fields, parameters, power, etc.) used by various STAs for determining / acquiring / configuring / calculating / decoding / encoding of transmission and reception signals can be stored in the memory (112, 122) of FIG. 1.

[0061] The device / STA of the aforementioned supplementary drawing (a) of FIG. 1 can be modified as shown in supplementary drawing (b) of FIG. 1. Hereinafter, the STA (110, 120) of this specification will be described based on supplementary drawing (b) of FIG. 1.

[0062] For example, the transceiver (113, 123) shown in side drawing (b) of FIG. 1 can perform the same function as the transceiver shown in side drawing (a) of FIG. 1 described above. For example, the processing chip (114, 124) shown in side drawing (b) of FIG. 1 may include a processor (111, 121) and a memory (112, 122). The processor (111, 121) and the memory (112, 122) shown in side drawing (b) of FIG. 1 can perform the same function as the processor (111, 121) and the memory (112, 122) shown in side drawing (a) of FIG. 1 described above.

[0063] The mobile terminal, wireless device, Wireless Transmit / Receive Unit (WTRU), User Equipment (UE), Mobile Station (MS), Mobile Subscriber Unit, user, User STA, network, Base Station, Node-B, AP (Access Point), repeater, router, relay, receiving device, transmitting device, receiving STA, transmitting STA, receiving Device, transmitting Device, receiving Apparatus, and / or transmitting Apparatus described below may refer to the STA (110, 120) shown in side drawings (a) / (b) of FIG. 1, or the processing chip (114, 124) shown in side drawing (b) of FIG. 1. That is, the technical features of the present specification may be performed in the STA (110, 120) shown in side drawings (a) / (b) of FIG. 1, or only in the processing chip (114, 124) shown in side drawing (b) of FIG. 1. For example, the technical feature of the transmitting STA transmitting a control signal may be understood as a technical feature in which a control signal generated in the processor (111, 121) shown in side drawings (a) / (b) of FIG. 1 is transmitted through the transceiver (113, 123) shown in side drawings (a) / (b) of FIG. 1. Alternatively, the technical feature of the transmitting STA transmitting a control signal may be understood as a technical feature in which a control signal to be transmitted from the processing chip (114, 124) shown in side drawing (b) of FIG. 1 is generated to the transceiver (113, 123).

[0064] For example, the technical feature of the receiving STA receiving a control signal can be understood as the technical feature of the control signal being received by the transceiver (113, 123) shown in side view (a) of FIG. 1. Alternatively, the technical feature of the receiving STA receiving a control signal can be understood as the technical feature of the control signal received by the transceiver (113, 123) shown in side view (a) of FIG. 1 being acquired by the processor (111, 121) shown in side view (a) of FIG. 1. Alternatively, the technical feature of the receiving STA receiving a control signal can be understood as the technical feature of the control signal received by the transceiver (113, 123) shown in side view (b) of FIG. 1 being acquired by the processing chip (114, 124) shown in side view (b) of FIG. 1.

[0065] Referring to side view (b) of FIG. 1, software code (115, 125) may be included in memory (112, 122). The software code (115, 125) may include instructions that control the operation of the processor (111, 121). The software code (115, 125) may be included in various programming languages.

[0066] The processor (111, 121) or processing chip (114, 124) illustrated in FIG. 1 may include an application-specific integrated circuit (ASIC), other chipsets, logic circuits, and / or data processing devices. The processor may be an application processor (AP). For example, the processor (111, 121) or processing chip (114, 124) illustrated in FIG. 1 may include at least one of a digital signal processor (DSP), a central processing unit (CPU), a graphics processing unit (GPU), and a modem (modulator and demodulator). For example, the processor (111, 121) or processing chip (114, 124) illustrated in FIG. 1 may be a SNAPDRAGON™ series processor manufactured by Qualcomm®, an EXYNOSTM series processor manufactured by Samsung®, an A series processor manufactured by Apple®, a HELIO™ series processor manufactured by MediaTek®, an ATOM™ series processor manufactured by INTEL®, or a processor enhanced therefrom.

[0067] In this specification, an uplink may refer to a link for communication from a non-AP STA to an AP STA, and uplink PPDUs / packets / signals, etc. may be transmitted through the uplink. Additionally, in this specification, a downlink may refer to a link for communication from an AP STA to a non-AP STA, and downlink PPDUs / packets / signals, etc. may be transmitted through the downlink.

[0068] Figure 2 is a conceptual diagram showing the structure of a wireless LAN (WLAN).

[0069] The top of Figure 2 shows the structure of the IEEE (Institute of Electrical and Electronic Engineers) 802.11 infrastructure BSS (basic service set).

[0070] The top of Figure 2 shows the structure of the IEEE (Institute of Electrical and Electronic Engineers) 802.11 infrastructure BSS (basic service set).

[0071] Referring to the top of FIG. 2, the wireless LAN system may include one or more infrastructure BSSs (200, 205) (hereinafter BSS). The BSS (200, 205) is a set of APs and STAs, such as an AP (access point, 225) and STA1 (Station, 200-1), that can communicate with each other by successfully synchronizing, and is not a concept referring to a specific area. The BSS (205) may include one or more STAs (205-1, 205-2) that can be combined with one AP (230).

[0072] The BSS may include at least one STA, an AP (225, 230) that provides a distribution service, and a distribution system (DS, 210) that connects multiple APs.

[0073] A distributed system (210) can implement an extended service set (ESS, 240) by connecting multiple BSSs (200, 205). The term ESS (240) may be used to refer to a network formed by connecting one or more APs through the distributed system (210). APs included in a single ESS (240) may have the same service set identification (SSID).

[0074] The portal (portal, 220) can act as a bridge to connect a wireless LAN network (IEEE 802.11) with another network (e.g., 802.X).

[0075] In a BSS like the one at the top of Fig. 2, a network between APs (225, 230) and a network between APs (225, 230) and STAs (200-1, 205-1, 205-2) can be implemented. However, it may also be possible to establish a network between STAs and perform communication without APs (225, 230). A network that establishes a network between STAs and performs communication without APs (225, 230) is defined as an ad-hoc network or an independent basic service set (IBSS).

[0076] The bottom of Fig. 2 is a conceptual diagram showing IBSS.

[0077] Referring to the bottom of Fig. 2, the IBSS is a BSS that operates in ad-hoc mode. Since the IBSS does not include an AP, there is no centralized management entity that performs management functions centrally. That is, in the IBSS, the STAs (250-1, 250-2, 250-3, 255-4, 255-5) are managed in a distributed manner. In the IBSS, all STAs (250-1, 250-2, 250-3, 255-4, 255-5) can be mobile STAs, and since access to the distributed system is not allowed, they form a self-contained network.

[0078] Figure 3 is a diagram illustrating a general link setup process.

[0079] In the described S310 step, the STA can perform a network discovery operation. The network discovery operation may include the STA's scanning operation. That is, in order for the STA to access a network, it must find a network it can join. Before joining a wireless network, the STA must identify a compatible network, and the process of identifying networks existing in a specific area is called scanning. Scanning methods include active scanning and passive scanning.

[0080] Figure 3 illustrates a network discovery operation that includes an active scanning process as an example. In active scanning, the STA performing the scanning moves between channels and transmits a probe request frame to search for nearby APs, and waits for a response. The responder transmits a probe response frame as a response to the probe request frame to the STA that transmitted the probe request frame. Here, the responder may be the STA that last transmitted a beacon frame from the BSS of the channel being scanned. In a BSS, the AP becomes the responder because it transmits the beacon frame, whereas in an IBSS, the responder is not constant because STAs within the IBSS take turns transmitting the beacon frame. For example, an STA that transmits a probe request frame on channel 1 and receives a probe response frame on channel 1 can store BSS-related information included in the received probe response frame and move to the next channel (e.g., channel 2) to perform scanning in the same way (i.e., transmit and receive probe request / response on channel 2).

[0081] Although not shown in the example of Fig. 3, scanning operations may also be performed using a passive scanning method. An STA performing scanning based on passive scanning can wait for a beacon frame while switching between channels. A beacon frame is one of the management frames in IEEE 802.11, which announces the presence of a wireless network and is periodically transmitted to allow a scanning STA to find the wireless network and join it. In a BSS, the AP performs the role of periodically transmitting beacon frames, while in an IBSS, STAs within the IBSS take turns transmitting beacon frames. When a scanning STA receives a beacon frame, it stores the information about the BSS included in the beacon frame and records the beacon frame information in each channel while moving to another channel. An STA that has received a beacon frame can store the BSS-related information included in the received beacon frame, move to the next channel, and perform scanning in the next channel in the same manner.

[0082] The STA that discovered the network can perform an authentication process through step S320. This authentication process may be referred to as the first authentication process to clearly distinguish it from the security setup operation of step S340 described later. The authentication process of S320 may include the STA sending an authentication request frame to the AP, and the AP sending an authentication response frame to the STA in response. The authentication frame used in the authentication request / response corresponds to a management frame.

[0083] The authentication frame may include information regarding the authentication algorithm number, authentication transaction sequence number, status code, challenge text, RSN (Robust Security Network), Finite Cyclic Group, etc.

[0084] The STA can send an authentication request frame to the AP. Based on the information contained in the received authentication request frame, the AP can determine whether to allow authentication for the STA. The AP can provide the result of the authentication process to the STA through an authentication response frame.

[0085] A successfully authenticated STA may perform an association process based on 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. For example, the association request frame may include information regarding various capabilities, beacon listen interval, service set identifier (SSID), supported rates, supported channels, RSN, mobility domain, supported operating classes, Traffic Indication Map Broadcast request, interworking service capabilities, etc. For example, a connection response frame may include information related to various capabilities, status code, AID (Association ID), support rate, EDCA (Enhanced Distributed Channel Access) parameter set, RCPI (Received Channel Power Indicator), RSNI (Received Signal to Noise Indicator), mobility domain, timeout interval (association comeback time), overlapping BSS scan parameters, TIM broadcast response, QoS map, etc.

[0086] Subsequently, in step S340, the STA may perform a security setup process. The security setup process of step S340 may include, for example, a process of setting up a private key through a 4-way handshake via an EAPOL (Extensible Authentication Protocol over LAN) frame.

[0087] FIG. 4 illustrates an example of a multi-link (ML).

[0088] As illustrated in FIG. 4, multiple multi-link devices (MLDs) can communicate through a multi-link. The MLDs can be classified into an AP MLD containing multiple AP STAs and a non-AP MLD containing multiple non-AP STAs. That is, the AP MLD may include affiliated APs (i.e., AP STAs), and the non-AP MLD may include affiliated STAs (i.e., non-AP STAs, or user-STAs).

[0089] A multilink may include a first link and a second link, and different channels / subchannels / frequency resources may be assigned to the first and second links. The first and second multilinks may be identified by a link ID of 4 bits (or other n bits). The first and second links may be configured in the same 2.4 GHz, 5 GHz, or 6 GHz band. Alternatively, the first link and the link may be configured in different bands.

[0090] The AP MLD of FIG. 4 includes three affiliated APs. In one example of FIG. 4, AP1 may operate in the 2.4 GHz band, AP2 may operate in the 5 GHz band, and AP3 may operate in the 6 GHz band. In one example of FIG. 4, the first link in which AP1 and non-AP1 operate may be defined as a channel / subchannel / frequency resource within the 2.4 GHz band. Additionally, in one example of FIG. 4, the second link in which AP2 and non-AP2 operate may be defined as a channel / subchannel / frequency resource within the 5 GHz band. Additionally, in one example of FIG. 4, the third link in which AP3 and non-AP3 operate may be defined as a channel / subchannel / frequency resource within the 6 GHz band.

[0091] In one example of FIG. 4, AP1 can initiate a multilink setup procedure (ML setup procedure) by transmitting an Association Request frame to non-AP STA1. In one example of FIG. 4, non-AP STA1 can transmit an Association Response frame in response to the Association Request frame. Each AP (e.g., AP1 / 2 / 3) shown in FIG. 4 may be the same as the AP shown in FIG. 1 and / or FIG. 2, and each non-AP (e.g., non-AP1 / 2 / 3) shown in FIG. 4 may be the same as the STA shown in FIG. 1 and / or FIG. 2 (i.e., user-STA or non-AP STA).

[0092] The specific features of this specification are not limited to the specific features of FIG. 4. That is, the number of links can be defined in various ways, and multiple links can be defined in various ways within at least one band.

[0093] FIG. 5 illustrates a PPDU (physical protocol data unit or physical layer (PHY) protocol data unit) transmitted / received in an STA of the present specification.

[0094] The STAs of this specification (e.g., AP STA, non-AP STA, AP MLD, non-AP MLD) can transmit and / or receive the PPDU of FIG. 5. The PPDU described in this specification may have the structure of FIG. 5, for example. Additionally, the PPDU described in this specification, the Ultra High Reliability (UHR) PPDU, may be referred to by various names such as transmit PPDU, receive PPDU, first type or N type PPDU. The PPDU described in this specification may be used in WLAN systems defined according to IEEE 802.11bn and / or next-generation WLAN systems that improve upon IEEE 802.11bn.

[0095] The PPDU of FIG. 5 may be related to various PPDU types used in a UHR system. For example, the example of FIG. 5 may be used for at least one of SU (single-user) mode / type / transmission, MU (multi-user) mode / type / transmission, and NDP (null data packet) mode / type / transmission related to channel sounding. For example, if the example of FIG. 5 is related to NDP, the illustrated Data field may be omitted. If the PPDU of FIG. 5 is used for TB (Trigger-based) mode, the UHR-SIG of FIG. 5 may be omitted. In other words, an STA that receives a Trigger frame for UL-MU (Uplink-MU) communication may transmit a PPDU in which the UHR-SIG is omitted in the example of FIG. 5.

[0096] In FIG. 5, L-STF to UHR-LTF can be called a preamble or physical preamble and can be generated / transmitted / received / acquired / decoded at the physical layer (included in the transmitting / receiving STA).

[0097] Each block illustrated in FIG. 5 may be referred to as a field / subfield / signal, etc. As illustrated in FIG. 5, the names of these fields / subfields / signals may be L-STF (legacy short training field), L-LTF (legacy long training field), L-SIG (legacy signal), RL-SIG (repeated L-SIG), U-SIG (Universal Signal), UHR-SIG (UHR-signal), etc.

[0098] The subcarrier spacing of the L-STF, L-LTF, L-SIG, RL-SIG, U-SIG, and UHR-SIG fields in Fig. 5 can be set to 312.5 kHz, and the subcarrier spacing of the UHR-STF, UHR-LTF, and Data fields can be set to 78.125 kHz. That is, the tone index (or subcarrier index) of the L-STF, L-LTF, L-SIG, RL-SIG, U-SIG, and UHR-SIG fields can be displayed in units of 312.5 kHz, and the tone index (or subcarrier index) of the UHR-STF, UHR-LTF, and Data fields can be displayed in units of 78.125 kHz.

[0099] The PPDU of Fig. 5, L-LTF and L-STF, may be the same as conventional fields (e.g., non-HT LTF and non-HT STF defined in conventional WLAN standards).

[0100] The L-SIG field of FIG. 5 may contain, for example, 24 bits of bit information. For example, the 24 bits of information may include a 4-bit Rate field, a 1-bit Reserved bit, a 12-bit Length field, a 1-bit Parity bit, and a 6-bit Tail bit. For example, the 12-bit Length field may contain information regarding the length or time duration of the PPDU. For example, the value of the 12-bit Length field may be determined based on the type of the PPDU. For example, if the PPDU is a non-HT (non-High Throughput), HT (High Throughput), VHT (Very High Throughput) PPDU, or an EHT (extremely high throughput) PPDU, or a UHR PPDU, the value of the Length field may be determined as a multiple of 3. For example, if the PPDU is an HE PPDU, the value of the Length field may be determined as "a multiple of 3 + 1" or "a multiple of 3 + 2". In other words, for non-HT, HT, VHT PPDU, or EHT PPDU, UHR PPDU, the value of the Length field can be determined as a multiple of 3, and for HE (High-Efficiency) PPDU, the value of the Length field can be determined as "a multiple of 3 + 1" or "a multiple of 3 + 2". In other words, the Length field in a UHR PPDU is set to a value satisfying the condition that the remainder is zero when LENGTH is divided by 3.

[0101] For example, a (non-AP and AP) STA can apply BCC encoding based on a code rate of 1 / 2 to 24 bits of information in the L-SIG field. Subsequently, the transmitting STA can obtain 48 bits of BCC encoding. BPSK modulation can be applied to the 48 bits of encoding to generate 48 BPSK symbols. The transmitting STA can map the 48 BPSK symbols to positions excluding the pilot subcarrier {subcarrier indices -21, -7, +7, +21} and the DC subcarrier {subcarrier index 0}. Consequently, the 48 BPSK symbols can be mapped to subcarrier indices -26 to -22, -20 to -8, -6 to -1, +1 to +6, +8 to +20, and +22 to +26. The transmitting STA can additionally map the signal of {-1, -1, -1, 1} to the subcarrier index {-28, -27, +27, +28}. The above signal can be used for channel estimation for the frequency domain corresponding to {-28, -27, +27, +28}.

[0102] For example, the (non-AP and AP) STA can generate an RL-SIG that is identical to the L-SIG. BPSK modulation may be applied to the RL-SIG. The receiving (non-AP and AP) STA can determine that the received PPDU is a HE PPDU, EHT PPDU, or UHR PPDU based on the presence of the RL-SIG. In other words, the receiving (non-AP and AP) STA can determine that the received PPDU is one of the HE PPDU, EHT PPDU, or UHR PPDU if the RL-SIG is present. In other words, the receiving (non-AP and AP) STA can determine that the received PPDU is one of the non-HT PPDU, HT PPDU, or VHT PPDU if the RL-SIG is not present. In other words, the RL-SIG field is a repeat of the L-SIG field and is used to differentiate an UHR PPDU from a non-HT PPDU, HT PPDU, and VHT PPDU.

[0103] After the RL-SIG in Fig. 5, a U-SIG (Universal SIG) may be inserted. The U-SIG may be referred to by various names such as the first SIG field, first SIG, first type SIG, control signal, control signal field, first (type) control signal, common control field, and common control signal.

[0104] U-SIG may contain N bits of information and may contain information to identify the type of EHT PPDU. For example, U-SIG may be constructed based on two symbols (e.g., two consecutive OFDM symbols). Each symbol for U-SIG (e.g., OFDM symbol) may have a duration of 4 us. Each symbol of U-SIG may be used to transmit 26 bits of information. For example, each symbol of U-SIG may be transmitted and received based on 52 data tones and 4 pilot tones.

[0105] For example, A bit information (e.g., 52 un-coded bits) can be transmitted through U-SIG, and the first symbol of U-SIG can transmit the first X bit information (e.g., 26 un-coded bits) of the total A bit information, and the second symbol of U-SIG can transmit the remaining Y bit information (e.g., 26 un-coded bits) of the total A bit information. For example, the transmitting STA can obtain the 26 un-coded bits included in each U-SIG symbol. The transmitting STA can generate 52-coded bits by performing convolutional encoding (i.e., BCC encoding) based on a rate of R=1 / 2 and can perform interleaving on the 52-coded bits. The transmitting STA can generate 52 BPSK symbols assigned to each U-SIG symbol by performing BPSK modulation on the interleaved 52-coded bits. A single U-SIG symbol can be transmitted based on 56 tones (subcarriers) from subcarrier index -28 to subcarrier index +28, excluding DC index 0. 52 BPSK symbols generated by the transmitting STA can be transmitted based on the remaining tones (subcarriers), excluding the pilot tones -21, -7, +7, and +21.

[0106] For example, A bit information (e.g., 52 un-coded bits) transmitted by U-SIG may include a CRC field (e.g., a field of 4 bits) and a tail field (e.g., a field of 6 bits). The CRC field and the tail field may be transmitted through a second symbol of U-SIG. The CRC field may be generated based on 26 bits assigned to the first symbol of U-SIG and the remaining 16 bits within the second symbol excluding the CRC / tail field, and may be generated based on a conventional CRC calculation algorithm. Additionally, the tail field may be used to terminate the trellis of a convolutional decoder and may be set, for example, to "000000".

[0107] A bit information (e.g., 52 un-coded bits) transmitted by U-SIG (or U-SIG field) can be divided into version-independent bits and version-dependent bits. For example, the size of the version-independent bits can be fixed or variable. For example, the version-independent bits may be assigned only to the first symbol of U-SIG, or the version-independent bits may be assigned to both the first and second symbols of U-SIG. For example, the version-independent bits and the version-dependent bits may be referred to by various names, such as the first control bit and the second control bit.

[0108] For example, the version-independent bits of U-SIG may include a 3-bit PHY version identifier. For example, the 3-bit PHY version identifier may include information related to the PHY version of the transmitted and received PPDU. For example, a first value of the 3-bit PHY version identifier (e.g., a value of 000) may indicate that the transmitted and received PPDU is an EHT PPDU. Additionally, a second value of the 3-bit PHY version identifier (e.g., a value of 001) may indicate that the transmitted and received PPDU is a UHR PPDU.

[0109] In other words, when an (AP / non-AP) STA transmits an EHT PPDU, it can set a 3-bit PHY version identifier to a first value. In other words, a receiving (AP / non-AP) STA can determine that the received PPDU is an EHT PPDU based on the PHY version identifier having the first value, and can determine that the received PPDU is a UHR PPDU based on the PHY version identifier having the second value.

[0110] For example, 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.

[0111] For example, the version-independent bits of U-SIG may include information regarding the length of the TXOP (transmission opportunity) and information regarding the BSS color ID.

[0112] For example, if the UHR PPDU is classified into various types (e.g., type related to SU transmission (performed based on UL or DL), type related to DL transmission, type related to NDP transmission, type related to DL non-MU-MIMO, type related to DL MU-MIMO, type related to Multi-AP operation, type related to CBF (Coordinated beamforming) and SR (Spatial Reuse), type related to C-OFDMA (Coordinated OFDMA), type related to C-TDMA (Coordinated TDMA)), information regarding the type of the EHT PPDU (e.g., 2-bit or 3-bit information) may be included in the version-dependent bits of the U-SIG.

[0113] For example, U-SIG may include: 1) a bandwidth field containing information regarding bandwidth; 2) a field containing information regarding the MCS technique applied to UHR-SIG; 3) a field containing information regarding the number of symbols used for UHR-SIG; 4) a field containing information regarding whether UHR-SIG is generated across the entire band; 5) a field containing information regarding the type of UHR-LTF / STF; and 6) information regarding a field indicating the length of UHR-LTF and CP length.

[0114] Preamble puncturing may be applied to the PPDU of Fig. 5. Preamble puncturing means applying puncturing to a portion of the total band of the PPDU (e.g., a secondary 20 MHz band). For example, when an 80 MHz PPDU is transmitted, the STA applies puncturing to the secondary 20 MHz band within the 80 MHz band and can transmit the PPDU only through the primary 20 MHz band and the secondary 40 MHz band.

[0115] For example, the pattern of preamble puncturing can be pre-set. For example, when a first puncturing pattern is applied, puncturing may be applied only to a secondary 20 MHz band within an 80 MHz band. For example, when a second puncturing pattern is applied, puncturing may be applied only to one of two secondary 20 MHz bands included in a secondary 40 MHz band within an 80 MHz band. For example, when a third puncturing pattern is applied, puncturing may be applied only to a secondary 20 MHz band included in a primary 80 MHz band within a 160 MHz band (or 80+80 MHz band). For example, when the fourth puncturing pattern is applied, within the 160 MHz band (or 80+80 MHz band), the primary 40 MHz band included in the primary 80 MHz band is present, and puncturing may be applied to at least one 20 MHz channel that does not belong to the primary 40 MHz band.

[0116] Information regarding preamble puncturing applied to the PPDU may be included in the U-SIG and / or UHR-SIG. For example, the first field of the U-SIG may include information regarding the contiguous bandwidth of the PPDU, and the second field of the U-SIG may include information regarding preamble puncturing applied to the PPDU.

[0117] For example, U-SIG and UHR-SIG may include information regarding preamble puncturing based on the following method. If the bandwidth of the PPDU exceeds 80 MHz, the U-SIG may be configured individually in 80 MHz units. For example, if the bandwidth of the PPDU is 160 MHz, the PPDU may include a first U-SIG for the first 80 MHz band and a second U-SIG for the second 80 MHz band. In this case, the first field of the first U-SIG may include information regarding the 160 MHz bandwidth, and the second field of the first U-SIG may include information regarding preamble puncturing applied to the first 80 MHz band (i.e., information regarding the preamble puncturing pattern). Additionally, the first field of the second U-SIG may include information regarding a 160 MHz bandwidth, and the second field of the second U-SIG may include information regarding preamble puncturing applied to the second 80 MHz band (i.e., information regarding a preamble puncturing pattern). Meanwhile, the UHR-SIG following the first U-SIG may include information regarding preamble puncturing applied to the second 80 MHz band (i.e., information regarding a preamble puncturing pattern), and the UHR-SIG following the second U-SIG may include information regarding preamble puncturing applied to the first 80 MHz band (i.e., information regarding a preamble puncturing pattern).

[0118] Additionally or generally, U-SIG and UHR-SIG may include information regarding preamble puncturing based on the following method. U-SIG may include information regarding preamble puncturing for all bands (i.e., information regarding preamble puncturing patterns). That is, UHR-SIG may not include information regarding preamble puncturing, and only U-SIG may include information regarding preamble puncturing (i.e., information regarding preamble puncturing patterns).

[0119] U-SIGs can be configured in 20 MHz units. For example, if an 80 MHz PPDU is configured, U-SIGs can be duplicated. That is, four identical U-SIGs can be included within an 80 MHz PPDU. PPDUs exceeding the 80 MHz bandwidth may contain different U-SIGs.

[0120] The UHR-SIG of FIG. 5 may include control information for a receiving STA. The UHR-SIG may be transmitted through at least one symbol, and one symbol may have a length of 4 us. Information regarding the number of symbols used for the UHR-SIG may be included in the U-SIG.

[0121] UHR-SIG provides additional signals to the U-SIG field, enabling the STA to interpret / decode the UHR PPDU. The UHR-SIG field may include U-SIG overflow bits that apply commonly to all users. Additionally, the UHR-SIG field contains resource allocation information, making it possible for the STA to look up resources used in fields containing data fields / UHR-STF / UHR-LTF (i.e., UHR modulated fields of an UHR PPDU).

[0122] The frequency resources of the UHR-LTF, UHR-STF, and data fields illustrated in FIG. 5 can be determined based on a RU (resource unit) defined by a plurality of subcarriers / tones. That is, the UHR-LTF, UHR-STF, and data fields of this specification can be transmitted / received through a RU (resource unit) defined by a plurality of subcarriers / tones.

[0123] FIG. 6 is a diagram showing the arrangement of resource units (RUs) used for a 20 MHz PPDU. That is, UHR-LTF, UHR-STF and / or data fields included in the 20 MHz PPDU can be transmitted / received through at least one of the various RUs defined in FIG. 6.

[0124] As shown at the top of Fig. 6, 26 units (i.e., units corresponding to 26 tones) may be arranged. Six tones may be used as a guard band in the leftmost band of the 20 MHz band, and five tones may be used as a guard band in the rightmost band of the 20 MHz band. Additionally, seven DC tones are inserted into the center band, i.e., the DC band, and 26 units corresponding to 13 tones may exist on the left and right sides of the DC band. Furthermore, 26 units, 52 units, and 106 units may be allocated to other bands. Each unit may be allocated for a receiving station, i.e., a user.

[0125] Meanwhile, the RU arrangement of Fig. 6 is utilized not only for situations involving multiple users (MU) but also for situations involving a single user (SU), in which case it is possible to use one 242-unit as shown at the bottom of Fig. 4, and in this case, three DC tones can be inserted.

[0126] In the example of FIG. 6, various sizes of RUs, namely 26-RU, 52-RU, 106-RU, 242-RU, etc., are proposed. Since the specific size of these RUs can be expanded or increased, the present embodiment is not limited to the specific size of each RU (i.e., the number of corresponding tones). In this specification, N-RU may be indicated as N-tone RU, etc. For example, 26-RU may be indicated as 26-tone RU.

[0127] Figure 7 is a diagram showing the arrangement of resource units (RU) used for a 40 MHz PPDU.

[0128] Just as various sizes of RUs were used in the example of FIG. 6, 26-RU, 52-RU, 106-RU, 242-RU, 484-RU, etc., may also be used in the example of FIG. 7. Additionally, 5 DC tones may be inserted at the center frequency, 12 tones may be used as guard bands in the leftmost band of the 40 MHz band, and 11 tones may be used as guard bands in the rightmost band of the 40 MHz band.

[0129] In addition, as described, 484-RU may be used when used for a single user. Meanwhile, the specific number of RUs may be changed, as in the example of FIG. 6.

[0130] FIG. 8 is a diagram showing the arrangement of resource units (RUs) used for an 80 MHz PPDU. The arrangement of resource units (RUs) used in this specification may be varied. For example, the arrangement of resource units (RUs) used in the 80 MHz band may be varied.

[0131] FIG. 9 illustrates the operation according to UL-MU. As illustrated, a transmitting STA (e.g., AP) can establish a channel connection through contending (i.e., Backoff operation) and transmit a Trigger frame (930). That is, the transmitting STA (e.g., AP) can transmit a PPDU containing the Trigger frame (930). When the PPDU containing the Trigger frame is received, a TB (trigger-based) PPDU is transmitted after a delay of SIFS.

[0132] TB PPDUs (941, 942) may be transmitted at the same time and may be transmitted from multiple STAs (e.g., User STAs) with AIDs indicated within the Trigger frame (930). The ACK frame (950) for the TB PPDU may be implemented in various forms.

[0133] Figure 10 shows an example of a channel used / supported / defined within the 2.4 GHz band.

[0134] The 2.4 GHz band may be referred to by other names, such as the first band (band). Additionally, the 2.4 GHz band may refer to a frequency range in which channels with a center frequency adjacent to 2.4 GHz (e.g., channels with a center frequency located between 2.4 and 2.5 GHz) are used / supported / defined.

[0135] The 2.4 GHz band may include multiple 20 MHz channels. The 20 MHz channels within the 2.4 GHz band may have multiple channel indices (e.g., indices 1 through 14). For example, the center frequency of a 20 MHz channel assigned to channel index 1 may be 2.412 GHz, the center frequency of a 20 MHz channel assigned to channel index 2 may be 2.417 GHz, and the center frequency of a 20 MHz channel assigned to channel index N may be (2.407 + 0.005*N) GHz. Channel indices may be referred to by various names, such as channel numbers. The specific numerical values ​​of channel indices and center frequencies may change.

[0136] FIG. 10 illustrates four channels within a 2.4 GHz band as an example. The illustrated first frequency range (1010) to fourth frequency range (1040) may each include one channel. For example, the first frequency range (1010) may include channel 1 (a 20 MHz channel having index 1). In this case, the center frequency of channel 1 may be set to 2412 MHz. The second frequency range (1020) may include channel 6. In this case, the center frequency of channel 6 may be set to 2437 MHz. The third frequency range (1030) may include channel 11. In this case, the center frequency of channel 11 may be set to 2462 MHz. The fourth frequency range (1040) may include channel 14. In this case, the center frequency of channel 14 may be set to 2484 MHz.

[0137] FIG. 11 illustrates an example of a channel used / supported / defined within the 5 GHz band.

[0138] The 5 GHz band may be referred to by other names such as the second band / band. The 5 GHz band may refer to a frequency range in which channels with a center frequency of 5 GHz or higher and less than 6 GHz (or less than 5.9 GHz) are used / supported / defined. Alternatively, the 5 GHz band may include multiple channels between 4.5 GHz and 5.5 GHz. The specific figures shown in FIG. 11 may be changed.

[0139] Multiple channels within the 5 GHz band include UNII (Unlicensed National Information Infrastructure)-1, UNII-2, UNII-3, and ISM. UNII-1 may be referred to as UNII Low. UNII-2 may include frequency regions referred to as UNII Mid and UNII-2 Extended. UNII-3 may be referred to as UNII-Upper.

[0140] Multiple channels may be configured within the 5 GHz band, and the bandwidth of each channel may be varied, such as 20 MHz, 40 MHz, 80 MHz, or 160 MHz. For example, the 5170 MHz to 5330 MHz frequency range within UNII-1 and UNII-2 may be divided into eight 20 MHz channels. The 5170 MHz to 5330 MHz frequency range may be divided into four channels through a 40 MHz frequency range. The 5170 MHz to 5330 MHz frequency range may be divided into two channels through an 80 MHz frequency range. Alternatively, the 5170 MHz to 5330 MHz frequency range may be divided into one channel through a 160 MHz frequency range.

[0141] FIG. 12 illustrates an example of a channel used / supported / defined within the 6 GHz band.

[0142] The 6 GHz band may be referred to by other names such as the third band / band. The 6 GHz band may refer to a frequency range in which channels with a center frequency of 5.9 GHz or higher are used / supported / defined. The specific figures shown in FIG. 12 are subject to change.

[0143] For example, the 20 MHz channel of FIG. 12 can be defined starting from 5.940 GHz. Specifically, the leftmost channel among the 20 MHz channels of FIG. 12 may have index 1 (or channel index, channel number, etc.), and the center frequency may be assigned as 5.945 GHz. That is, the center frequency of the index N channel may be determined as (5.940 + 0.005*N) GHz.

[0144] Accordingly, the indices (or channel numbers) of the 20 MHz channel in FIG. 12 are 1, 5, 9, 13, 17, 21, 25, 29, 33, 37, 41, 45, 49, 53, 57, 61, 65, 69, 73, 77, 81, 85, 89, 93, 97, 101, 105, 109, 113, 117, 121, 125, 129, 133, 137, 141, 145, 149, 153, 157, 161, 165, 169, 173, 177, 181, 185, 189, 193, 197, It may be 201, 205, 209, 213, 217, 221, 225, 229, 233. Also, according to the (5.940 + 0.005*N) GHz rule described above, the index of the 40 MHz channel of FIG. 12 may be 3, 11, 19, 27, 35, 43, 51, 59, 67, 75, 83, 91, 99, 107, 115, 123, 131, 139, 147, 155, 163, 171, 179, 187, 195, 203, 211, 219, 227.

[0145] The structure and types / subtypes of MAC frames are described below.

[0146] FIG. 13 shows an example of a MAC frame header. As illustrated, the MAC frame may include a frame control field / information of 2 octets, a duration field / information of 2 octets, a Receiver Address (RA) field / information of 6 octets, and a Transmitter Address (TA) field / information of 6 octets. As illustrated in FIG. 13, the four fields may be consecutive. The MAC header of FIG. 13 may be modified in various ways, and a new field may be inserted between the four illustrated fields, or at least one of the illustrated fields may be omitted.

[0147] The MAC header shown in FIG. 13 may be located at the very beginning of the MAC frame. That is, the MAC frame may include a MAC header such as that in FIG. 13 and a MAC body field / information following the MAC header. The MAC frame containing the MAC header of FIG. 13 is inserted / included in the data field of the PPDU (e.g., UHR PPDU) shown in FIG. 5.

[0148] MAC frames included in the data fields of the PPDU of this specification may be classified into various types. For example, MAC frames of this specification may be classified into control frames, management frames, and data frames.

[0149] For example, a management frame includes Association Request, Association Response, Reassociation Request, Reassociation Response, Probe Request, Probe Response, Beacon, Disassociation, Authentication, and Deauthentication frames / signals defined in conventional WLANs. For the management frame, the values ​​of the type fields (B3 and B2) in FIG. 13 are set to 00. Additionally, the values ​​of the subtype fields (B7, B6, B5, B4) in FIG. 13 are as follows: Association Request (0000), Association Response (0001), Reassociation Request (0010), Reassociation Response (0011), Probe Request (0100), Probe Response (0101), Beacon (1000), Disassociation (1010), Authentication (1011), Deauthentication (1100).

[0150] For example, the control frame includes the Trigger Beamforming Report Poll, NDP Announcement (NDPA), Control Frame Extension, Control Wrapper, Block Ack Request (BlockAckReq), Block Ack (BlockAck), PS-Poll, RTS, CTS, Ack, and CF-End frames / signals defined in conventional WLANs. For the control frame, the values ​​of the type fields (B3 and B2) in FIG. 13 are set to 01. Also, the values ​​of the subtype fields (B7, B6, B5, B4) of FIG. 13 are as follows: Trigger(0010), Beamforming Report Poll(0100), NDP Announcement(0101), Control Frame Extension(0110), Control Wrapper(0111), BlockAckReq(1000), BlockAck(1001), PS-Poll(1010), RTS(1011), CTS(1100), Ack(1101), CF-End(1110).

[0151] For example, the data frame includes (QoS) Data, (QoS) Null, etc., defined in conventional WLANs. For the management frame, the value of the type field (B3 and B2) in FIG. 13 is set to 10.

[0152] MAC frames / signals used in this specification can be identified through the type field / information and subtype field / information described above. For example, the “frame” in this specification may refer to a MAC frame in which the type bits B3 and B2 within the frame control field of the MAC header are set to 01, and the subtype bits B7, B6, B5, and B4 within the frame control field are set to 0010. Various MAC frames described in this specification are inserted into / included in the data fields of various PPDUs (e.g., HE / VHT / HE / EHT / UHR PPDU).

[0153] FIG. 14 shows a modified example of a transmitting device and / or receiving device of the present specification.

[0154] The device illustrated in FIGS. 1 to 4 (e.g., AP STA, non-AP STA) can be modified as in FIG. 14. The transceiver (1430) of FIG. 14 may be identical to the transceiver (113, 123) of FIG. 1. The transceiver (1430) of FIG. 14 may include a receiver and a transmitter.

[0155] The processor (1410) of FIG. 14 may be the same as the processor (111, 121) of FIG. 1. Or, the processor (1410) of FIG. 14 may be the same as the processing chip (114, 124) of FIG. 1.

[0156] The memory (1420) of FIG. 14 may be the same as the memory (112, 122) of FIG. 1. Alternatively, the memory (1420) of FIG. 14 may be a separate external memory different from the memory (112, 122) of FIG. 1.

[0157] Referring to FIG. 14, a power management module (1411) manages power for a processor (1410) and / or a transceiver (1430). A battery (1412) supplies power to the power management module (1411). A display (1413) outputs results processed by the processor (1410). A keypad (1414) receives input to be used by the processor (1410). The keypad (1414) may be displayed on the display (1413). A SIM card (1415) may be an integrated circuit used to securely store an international mobile subscriber identity (IMSI) and associated keys used to identify and authenticate a subscriber in a mobile device such as a mobile phone and a computer.

[0158] Referring to FIG. 14, the speaker (1440) can output sound-related results processed by the processor (1410). The microphone (1441) can receive sound-related inputs to be used by the processor (1410).

[0159] In this specification, subcarrier and tone are used interchangeably.

[0160] 1. Definition of an IM Pilot

[0161] IM (Interference Mitigation) is a technology that enables reliable reception of PPDUs in the presence of interference signals, and can use additional pilots in the data portion of the PPDU to mitigate interference.

[0162] A UHR (Ultra High Reliability) STA can transmit an IM-enabled UHR PPDU only if all of the following conditions are satisfied.

[0163] - The UHR PPDU must be a Single-user SU using the UHR MU PPDU format.

[0164] - The Punctured Channel Information field in the U-SIG field must be set to 0. (No channel puncturing)

[0165] - The UL / DL field of the U-SIG field must be set to 1 (UL transport) or the UL / DL field must be set to 0 (DL transport) and the data field must use only one spatial stream.

[0166] - Data fields must not use UHR-MCS (Ultra High Reliability-Modulation and Coding Scheme) 15.

[0167] The transmission of the IM pilot is used only in LDPC (Low Density Parity Check), and when IM is enabled, the number of data bits per symbol (N DBPS ), number of coding bits per symbol (N CBPS ), and the number of data subcarriers (N SD ) decreases.

[0168] The IM pilot is used in all OFDM (Orthogonal Frequency Division Multiplexing) symbols, and for a specific bandwidth (BW), its subcarrier position can be fixed in all OFDM symbols. The IM pilot has zero energy.

[0169] To disperse IM pilots in the frequency domain, these zero-value pilots are first inserted into the LDPC tone mapper.

[0170] For 160 MHz and 320 MHz, IM pilots can be inserted individually within each 80 MHz sub-block.

[0171] Number of IM pilots (N SP,IM ) and LDPC tone mapper block size (N TM ) can also be defined as Table 1 as follows.

[0172] ParameterCBW20CBW40CBW80CBW160CBW320DescriptionN SD,total 20841688217643528Total number of data subcarriersN SP,IM 265298196392Number of IM pilotsN TM 234468980980980LDPC Tone Mapper block sizeN SP 816163264Number of pilot subcarriersN ST 24248499619923984Total number of subcarriersN SR 12224450010122036Highest data subcarrier indexN DC 3552323Number of null subcarriers at DCN Guard,Left 612121212Number of low frequency guard subcarriersN Guard,Right 511111111Number of high frequency guard subcarriers

[0173] However, N in the table above SD,total, N SP,IM The value of the parameter may vary depending on the placement of the pilot subcarriers. When encoded using the LDPC method, the data field may contain the LDPC-encoded data and the IM pilot. For example, the index of the LDPC-encoded data can be determined by the following Equation 1. However, the following Equation is merely an example, and the index of the LDPC-encoded data can be determined in a different way.

[0174] [Mathematical Formula 1]

[0175] t(k, l) = ( D TM_l * ( k mod (N TM / DTM_l ) ) + γ+ floor( (k * D TM_l ) / N TM ) ) mod N TM

[0176] Here, D TM_l represents the LDPC tone mapping distance for the portion where the RU or MRU is located in the l-th frequency subblock. In this case, the LDPC tone mapping distance is a number that determines the tone interval at which the LDPC-encoded bits are placed in the subcarrier. k represents the index for the subcarrier to which the data encoded using the LDPC method is mapped to the said RU or MRU. N TM represents the LDPC subcarrier mapper block size. In this case, the LDPC subcarrier mapper block size is the sum of the number of data subcarriers and IM pilots included in the corresponding bandwidth, and examples of LDPC subcarrier mapper block size values ​​for each bandwidth are listed in Table 1 above.

[0177] γ is determined by the following mathematical formula 2.

[0178] [Mathematical Formula 2]

[0179] γ = floor(D TM_l / 2),

[0180] In the case of a 242-tone RU, γ is 4.

[0181] In the case of a 484-tone RU, γ is 4.

[0182] In the case of 996-tone RU, 2x996-tone RU, or 4x996-tone RU, γ is 5.

[0183] 2. Characteristics of the IM Pilot

[0184] 802.11bn defines interference mitigation to prevent signal reception performance degradation caused by interference from OBSS or other STAs during transmission and reception between an AP and a non-AP. In order to eliminate the effects of such interference, it is necessary to define a pilot tone (i.e., IM pilot) to measure interference. This specification proposes a method for allocating an IM pilot tone to measure interference during signal transmission and reception using a 40 MHz channel.

[0185] The IM pilot transmitted for interference measurement and mitigation is additionally defined separately from the existing pilot transmitted for CFO tracking and compensation. Furthermore, the said IM pilot can be defined so as not to overlap with the existing pilot.

[0186] When transmitting with the addition of an IM pilot to reduce the impact of interference, some subcarriers are allocated for the IM pilot, so the number of subcarriers used for data transmission can be reduced.

[0187] In this specification, the range of subcarriers constituting a 484-tone RU in a 40 MHz bandwidth may be defined by an index such as [-244:-3, 3:244]. Data, existing pilot (CFO pilot), or IM pilot may be assigned to the subcarriers constituting the 484-tone RU.

[0188] The transmission of IM pilots for interference mitigation on the receiving side can be performed during non-OFDMA (non-Orthogonal Frequency Division Multiple Access) transmission, that is, SU transmission. In addition, IM pilots may not be considered in MU-MIMO (Multi-User Multiple Input Multiple Output) to reduce the ease and complexity of implementation.

[0189] 3. IM Pilot Subcarrier Index Setting Process

[0190] The tone plan considered for 40 MHz transmission in UHR is as follows.

[0191] This specification proposes a 40 MHz IM pilot tone plan. It assumes the same 484 tone RU size as the 40 MHz RU tone plan defined in 802.11ax / 802.11bn, and the same locations and number of guard subcarrier / null subcarrier / DC subcarrier / CFO pilots.

[0192] The subcarrier range constituting the 484-tone RU used for 40MHz transmission in UHR is [-244:-3, 3:244]. The index of the CFO pilot tone defined within the subcarrier range constituting the 484-tone RU is [-238, -212, -170, -144, -104, -78, -36, -10, 10, 36, 78, 104, 144, 170, 212, 238].

[0193] IM pilots for measuring and mitigating interference during signal transmission and reception using a 40 MHz PPDU can be defined by being evenly distributed across available tones within 40 MHz. At this time, the index of the IM pilot is defined so as not to overlap with the existing pilot (i.e., CFO pilot) of the 40 MHz / 484 tone RU.

[0194] The IM pilot can be defined as follows when transmitting a 40 MHz PPDU.

[0195] 3.1 Tone plan when IM pilots exist at 4 subcarrier intervals

[0196] IM pilot tones are assigned within the available tone range so as not to overlap with existing pilot tones (i.e., CFO pilot tones). Negative tones among the IM pilot tones can be assigned evenly across four subcarrier intervals from the lowest tone to the DC tone. In this case, the index of the lowest tone available for 40MHz PPDU transmission is -243. Positive tones of the IM pilot tone can be assigned by applying mirror symmetry. The IM pilot tone plan, assigned across four subcarrier intervals so as not to overlap with existing pilot tones (i.e., CFO pilot tones), is defined as follows.

[0197] (1) Method 1-1

[0198] IM pilot tone plan with 4 subcarrier intervals

[0199] : [-243:4:-3, 3:4:243]

[0200] As described above, IM pilot tones are assigned to a total of 122 tones within the subcarrier range constituting the 484-tone RU and used for interference mitigation.

[0201] (2) Method 1-2

[0202] Unlike the above method 1-1, to reduce the number of IM pilot tones and thereby reduce the reduction in tones used for data transmission, negative tones among the IM pilot tones are evenly distributed from the tone at the index (i.e., -241) which is shifted three tones from the index of the lowest tone available for 40MHz PPDU transmission (i.e., -243) to the DC tone. Positive tones of the IM pilot tones are assigned by applying mirror symmetry to the negative tones of the IM pilot tones.

[0203] IM pilot tone plan with 4 subcarrier intervals

[0204] : [-241:4:-5, 241:4:5]

[0205] As described above, by shifting the start tone to assign IM pilot tones, the number of assigned IM pilot tones becomes 120, which has the effect of defining fewer IM pilot tones than in Method 1-1 and using more subcarriers for data transmission.

[0206] Accurate interference measurement and mitigation can be performed by allocating 120 / 122 tones within the available tone range as IM pilot tones and defining approximately 25~26% of the available tones for interference measurement and mitigation.

[0207] 3.2 Tone plan when IM pilots exist at 6 subcarrier intervals

[0208] To reduce the overhead for IM pilot tones, IM pilot tones can be allocated at six subcarrier intervals within the available tone range. In this case, the allocated IM pilot tones are defined so as not to overlap with existing pilot tones.

[0209] (1) Method 2-1

[0210] IM pilot tone plan with 6 subcarrier intervals

[0211] : [-243:6:-3, 3:6:243]

[0212] As described above, a total of 82 tones are allocated as IM pilot tones within the subcarrier range constituting the existing 484-tone RU and used for interference mitigation. By defining fewer IM pilot tones than in Method 1, the reduction in tones used for data transmission can be reduced, thereby reducing the impact of IM pilot overhead.

[0213] (2) Method 2-2

[0214] To reduce the number of IM pilot tones while avoiding overlap between the existing pilot tone (i.e., CFO pilot) and the IM pilot tone, negative tones among the IM pilot tones are assigned at intervals of 6 subcarriers from the tone at the index (i.e., -241) which is shifted 3 tones from the lowest tone index (i.e., -243) where IM pilot tone assignment begins, to the DC tone. Positive tones are assigned by applying mirror symmetry to the negative tones of the above IM pilot tones.

[0215] IM pilot tone plan with 6 subcarrier intervals

[0216] : [-241:6:-7, 7:6:241]

[0217] By allocating only 80 IM pilot tones within the subcarrier range constituting the 484-tone RU, the pilot overhead can be further reduced compared to Method 2-1.

[0218] (3) Method 2-3

[0219] To assign pilot tones closer to the DC tone while avoiding overlap between the existing pilot tone and the IM pilot tone, the tone index at which the assignment of IM pilot tones begins is shifted to assign negative tones among the IM pilot tones at intervals of 6 subcarriers from the tone with index -239 to the DC tone. Positive tones are assigned by applying mirror symmetry to the above negative tones. At this time, the total number of tones assigned as IM pilot tones is defined as 80.

[0220] IM pilot tone plan with 6 subcarrier intervals

[0221] : [-239:6:-5, 5:6:239]

[0222] By defining the IM pilot tone as described above, the number of IM pilot tones can be reduced by two compared to Method 2-1, thereby reducing the IM pilot overhead.

[0223] In addition, by assigning an IM pilot tone near the DC tone, it can have robust characteristics against signal distortion near the DC tone.

[0224] When configuring a PPDU by allocating IM pilot tones at intervals of 6 subcarriers, 17~18% of the subcarriers constituting a 484-tone RU are allocated as IM pilot tones, which has the effect of reducing overhead for IM pilot tones and improving data reception performance through smooth IM execution.

[0225] 4. IM pilot tone plan considering pilot overhead reduction

[0226] IM pilots are transmitted through the tones of the data field (i.e., the subcarriers constituting the 484-tone RU). Therefore, defining and inserting many IM pilots for interference mitigation has the disadvantage of increasing pilot overhead and reducing data throughput. To compensate for this, only 10–11% of the subcarriers constituting the 484-tone RU can be allocated to IM pilots.

[0227] 4.1 Tone plan when IM pilots exist at 9 subcarrier intervals

[0228] The IM pilot tone is defined so as not to overlap with existing pilot tones defined in the subcarriers constituting the 484-tone RU in the 40 MHz bandwidth.

[0229] The above IM pilot tone is defined within the range of subcarriers constituting the 484-tone RU, [ -244:-3, 3: 244], and can be defined using or not using mirror symmetry within the range of subcarriers constituting the 484-tone RU.

[0230] (1) Method 1-1. No mirror symmetric case

[0231] For example, in the no mirror symmetric case, the tone plan for the IM pilot can be defined as follows.

[0232] [-240:9:237]

[0233] The IM pilot is defined within the range of the subcarriers constituting the 484-tone RU, and implementation is easy because the IM pilot is defined using tone locations set at a constant interval of 9 tones. However, there is a disadvantage that interference measurements may be inaccurate when transmitted at low or high frequencies because the intervals from the left guard and right guard to the IM pilot tone are different.

[0234] (2) Method 1-2. Mirror symmetric case

[0235] An IM pilot defined at a negative tone index centered on DC is identically defined at a positive tone index using mirror symmetry. In the mirror symmetric case, the tone plan for the IM pilot can be defined as one of the following tone plans.

[0236] [-241:9:-7] [7:9:241]

[0237] [-240:9:-6] [6:9:240]

[0238] [-236:9:-11] [11:9:236]

[0239] The first and second tone plans allocate 54 IM pilots.

[0240] The third tone plan allocates 52 IM pilots, which can reduce the overhead caused by IM pilots compared to other tone plans.

[0241] Assigning IM pilot tones using mirror symmetry has the advantage of being easy to implement and requiring minimal memory for tone allocation.

[0242] Figure 15 shows an example of an IM pilot being inserted.

[0243] In Fig. 15, 54 IM pilot tones and 414 LDPC encoded data are inserted into the data field at regular index intervals in a 40 MHz transmission.

[0244] 54 IM pilot tones are arranged with 9 subcarrier intervals.

[0245] Specifically, in FIG. 15, the IM pilot tone is inserted into the tone index of [-240:9:-6] [6:9:240].

[0246] LDPC encoded data is first placed in 54 tones at intervals of 9 subcarriers, starting from the tone with an index that is 1 greater than the first index of the IM pilot tone (i.e., IM pilot 0) (i.e., Data Tone 0), and then the process is repeated by returning to the beginning and placing the next 54 tones at intervals of 9 subcarriers, starting from the tone with the next index (i.e., Data tone 54), so that all 414 LDPC encoded data are placed.

[0247] γ (i.e., gamma in Fig. 15) is the interval between the index of the left guard subcarrier (i.e., -244 in Fig. 15) and the index of the first IM pilot subcarrier (i.e., -240 in Fig. 15).

[0248] γ is determined by mathematical formula 2.

[0249] However, Fig. 15 is exemplary, and the tone placement method of the LDPC encoded data may vary depending on the placement of the CFO pilot.

[0250] 4.2 Tone plan when IM pilots exist at 10 subcarrier intervals

[0251] The IM pilot tone is defined so as not to overlap with the existing pilot tone (i.e., CFO pilot) defined in the 40 MHz RU tone plan.

[0252] The above IM pilot tone is defined within the range of subcarriers constituting the 484-tone RU, [-244:-3, 3:244], and can be defined using or not using mirror symmetry within the range of subcarriers constituting the 484-tone RU.

[0253] (1) Method 2-1. No mirror symmetric case

[0254] The tone plan for the IM pilot can be defined as one of the following tone plans.

[0255] [-243:10:237]

[0256] [-237:10:243]

[0257] [-235:10:235]

[0258] The first and second tone plans allocate 49 tones for the IM pilot.

[0259] The third tone plan allocates 48 tones for the IM pilot. Additionally, the third tone plan allocates the IM pilot at equal intervals from the left guard and right guard, and the IM pilot tones are spaced at regular intervals from the guard tone and DC tone, which has the effect of reducing the influence of the guard tone and DC tone.

[0260] (2) Method 2-2. mirror symmetric case

[0261] An IM pilot tone plan with 10 subcarrier intervals and mirror symmetry applied can be defined as one of the following tone plans.

[0262] [-243:10:-3] [3:10:243]

[0263] [-241:10:-11] [11:10:241]

[0264] [-239:10:-9] [9:10:239]

[0265] [-237:10:-7] [7:10:237]

[0266] [-235:10:-5] [5:10:235]

[0267] The first tone plan can improve the accuracy of IM by defining 50 IM pilots, but it has the disadvantage that the assigned IM pilots are adjacent to the guard tone and DC tone, so they can be affected by the guard tone and DC tone.

[0268] The second to fourth tone plan defines 48 IM pilots. By defining IM pilots using tones spaced similarly from the guard tone and DC tone, errors during expolation can be reduced.

[0269] 4.3 Tone plan when IM pilots exist at 11 subcarrier intervals

[0270] IM pilot is defined using fixed tone locations within 40 MHz with 11 subcarrier intervals.

[0271] Since the IM pilot tone interval is 11 subcarrier intervals, it has the advantage of reducing pilot overhead more than 4.1 & 4.2.

[0272] The above IM pilot tone is defined within the range of subcarriers constituting the 484-tone RU, [-244:-3, 3:244], and can be defined using mirror symmetry within the range of subcarriers constituting the 484-tone RU.

[0273] A tone plan to ensure that the IM pilot is positioned in 11 subcarrier units and does not overlap with existing pilot tones within the subcarriers constituting the 484-tone RU can be defined as follows.

[0274] [-244:11:-13] [13:11:244]

[0275] [-242:11:-11] [11:11:242]

[0276] [-240:11:-9] [9:11:240]

[0277] [-235:11:-4] [4: 11: 235]

[0278] The above IM pilot tone plan defines 44 IM pilot tones within the range of subcarriers constituting a 484-tone RU.

[0279] The IM pilot tone proposed in this specification can be set to have the same power value or to have zero power.

[0280] The IM pilot for interference mitigation used in this specification is an example and may be defined differently.

[0281] The IM pilot proposed in this specification is different from existing pilots defined for CFO tracking and does not have the same tone location.

[0282] FIG. 16 is a flowchart illustrating the operation of a transmitting device according to the present embodiment.

[0283] An example of FIG. 16 can be performed on a transmitting STA or a transmitting device (AP and / or non-AP STA).

[0284] Some of the steps (or detailed sub-steps described later) of the example in Fig. 16 may be omitted or changed.

[0285] Through step S1610, the transmitting device (transmitting STA) can obtain information regarding the above-described Tone Plan. As described above, the information regarding the Tone Plan includes the size and location of the RU, control information related to the RU, information regarding the frequency band in which the RU is included, information regarding the STA receiving the RU, etc.

[0286] Through step S1620, the transmitting device can construct / generate a PPDU based on the acquired control information. The step of constructing / generating the PPDU may include the step of constructing / generating each field of the PPDU. That is, step S1620 includes the step of constructing a UHR-SIG field containing control information regarding a Tone Plan. That is, step S1620 may include the step of constructing a field containing control information (e.g., N bitmap) indicating the size / location of the RU and / or the step of constructing a field containing an identifier (e.g., AID) of the STA receiving the RU.

[0287] Additionally, step S1620 may include the step of generating an STF / LTF sequence transmitted through a specific RU. The STF / LTF sequence may be generated based on a pre-configured STF generation sequence / LTF generation sequence.

[0288] Additionally, step S1620 may include a step of generating a data field (i.e., MPDU) transmitted through a specific RU. The step of generating the data field may include a step of configuring it by applying UEQM / EQM.

[0289] The transmitting device can transmit the PPDU configured through step S1620 to the receiving device based on step S1630.

[0290] While performing step S1630, the transmitting device may perform at least one of the following operations: CSD, Spatial Mapping, IDFT / IFFT operation, GI insertion, etc.

[0291] A signal / field / sequence configured according to the present specification can be transmitted in the form of FIG. 5.

[0292] FIG. 17 is a flowchart illustrating the operation of a receiving device according to the present embodiment.

[0293] The above-described PPDU can be received according to an example of FIG. 17.

[0294] An example of FIG. 17 can be performed at a receiving STA or a receiving device (AP and / or non-AP STA).

[0295] Some of the steps (or detailed sub-steps described later) of each example in Fig. 17 may be omitted.

[0296] A receiving device (receiving STA) can receive all or part of the PPDU through step S1710. The received signal may be in the form of FIG. 5.

[0297] The sub-step of step S1710 can be determined based on step S1630 of FIG. 16. That is, step S1710 can perform an operation to restore the results of the CSD, Spatial Mapping, IDFT / IFFT operation, and GI insert operation applied in step S1630.

[0298] In step S1720, the receiving device can perform decoding of all or part of the PPDU. Additionally, the receiving device can obtain control information related to the Tone Plan (i.e., RU) from the decoded PPDU.

[0299] More specifically, the receiving device can decode the L-SIG, U-SIG, and UHR-SIG of the PPDU based on the Legacy STF / LTF and obtain information contained in the L-SIG, U-SIG, and UHR-SIG fields. Information regarding various Tone Plans (i.e., RU) described herein may be included in the UHR-SIG, and the receiving STA can obtain information regarding the Tone Plan (i.e., RU) through the UHR-SIG. Additionally, information regarding the application of UEQM / EQM can be obtained through the UHR-SIG.

[0300] In step S1730, the receiving device can decode the remainder of the PPDU based on information regarding the Tone Plan (i.e., RU) and UEQM / EQM obtained through step S1820. For example, the receiving STA can decode the STF / LTF field of the PPDU based on information regarding the one Plan (i.e., RU). Additionally, the receiving STA can decode the data field of the PPDU based on information regarding the Tone Plan (i.e., RU) and UEQM / EQM information, and obtain the MPDU contained in the data field.

[0301] Additionally, the receiving device can perform a processing operation to transmit the decoded data through step S1730 to an upper layer (e.g., MAC layer). Furthermore, if the generation of a signal is instructed from the upper layer to the PHY layer in response to the data transmitted to the upper layer, a subsequent operation can be performed.

[0302] Hereinafter, the above-described embodiment will be explained with reference to FIGS. 1 to 17.

[0303] FIG. 18 is a flowchart illustrating the procedure for a non-AP STA to receive a PPDU according to the present embodiment.

[0304] An example of FIG. 18 can be performed in a network environment that supports a next-generation wireless LAN system (UHR (Ultra High Reliability) wireless LAN system or next wi-fi). The next-generation wireless LAN system is a wireless LAN system that improves upon the 802.11be system and can satisfy backward compatibility with the 802.11be system.

[0305] An example of FIG. 18 can be performed at a non-AP STA (non-access point station). The non-AP STA can be replaced with a non-AP MLD (non-access point Multi-link Device). The AP (access point) of FIG. 18 can be replaced with an AP MLD.

[0306] This embodiment proposes a method for defining an interference mitigation (IM) pilot to measure and mitigate interference coming from the Overlapping Basic Service Set (OBSS) in order to increase the reliability of signal transmission and reception between an AP and a non-AP in Next Wi-Fi (beyond 11be). Specifically, this embodiment proposes a method for deploying an IM pilot to perform interference mitigation during signal transmission and reception using a 40 MHz BW.

[0307] In step S1810, the non-AP STA (non-access point station) receives a PPDU (Physical Protocol Data Unit) from the AP (access point).

[0308] In step S1820, the non-AP STA decodes the PPDU.

[0309] The above PPDU includes a data field.

[0310] The above data field includes an IM (Interference Mitigation) pilot having 0 energy.

[0311] Based on the fact that the bandwidth of the above PPDU is 40 MHz, the above IM pilot,

[0312] It is inserted at intervals of 9 indices from the first subcarrier index to the second subcarrier index, and at intervals of 9 indices from the third subcarrier index to the fourth subcarrier index.

[0313] The first subcarrier index may be -240, the second subcarrier index may be -6, the third subcarrier index may be 6, and the fourth subcarrier index may be 240. For example, the index of the subcarrier into which the IM pilot is inserted may be represented as [-240:9:-6], [6:9:240], etc. That is, when many IM pilots are defined and inserted, the pilot overhead increases, and the number of subcarriers for data transmission decreases. To compensate for this, when considering the IM pilot overhead as 10~11%, the IM pilot can be defined at intervals of 9 subcarrier units. When IM pilots are placed at intervals of 9 subcarriers, there is an effect of reducing pilot overhead compared to placing them at intervals of 4 to 6 subcarriers. Additionally, the subcarrier placement of the above IM pilot is positioned at a certain distance from the guard subcarrier and DC (Direct Current) subcarrier, which has the effect of reducing the influence of the guard subcarrier and DC subcarrier.

[0314] For example, the above IM pilot can be deployed based on a negative subcarrier index and a positive subcarrier index that form mirror symmetry.

[0315] At this time, the positive subcarrier index may be configured to have the same absolute value as the negative subcarrier index and the opposite sign.

[0316] In other words, when the IM pilot does not form mirror symmetry, implementation is easy because the IM pilot is defined using fixed subcarrier positions in units of 9 subcarriers; however, there is a disadvantage that interference measurements may be inaccurate when transmitted at low or high frequencies because the spacing between the IM pilot subcarriers from the left guard subcarrier and the right guard subcarrier is different. Therefore, by placing the IM pilot at a mirror-symmetric subcarrier index, the IM pilot defined by the negative subcarrier index centered on DC (Direct Current) is defined identically at the positive subcarrier index.

[0317] The above IM pilot may include 54 subcarriers.

[0318] The above data field may further include a CFO (Carrier Frequency Offset) pilot.

[0319] At this time, the subcarrier index of the IM pilot can be positioned so as not to overlap with the subcarrier index of the CFO pilot.

[0320] The above PPDU may be a SU (Single User) PPDU.

[0321] In addition, the above IM pilot can be used based on the data field being encoded using the LDPC (Low Density Parity Check) method.

[0322] Based on the use of the above IM pilot, the data subcarrier of the data field can be reduced. That is, the range of subcarriers constituting a 484-tone RU in a 40 MHz bandwidth can be defined by an index such as [-244:-3, 3:244], and when transmitting with the addition of the above IM pilot, a portion of the subcarriers constituting the 484-tone RU is allocated for the IM pilot, so the number of subcarriers used for data transmission can be reduced.

[0323] In this specification, the subcarrier constituting the 484-tone RU is a subcarrier that can be used for signal transmission and reception using the 484-tone RU in a 40 MHz bandwidth. A data subcarrier, an existing pilot (CFO pilot) subcarrier, or the IM pilot subcarrier may be assigned to the subcarrier constituting the 484-tone RU.

[0324] FIG. 19 is a flowchart illustrating the procedure for an AP to transmit a PPDU according to the present embodiment.

[0325] An example of FIG. 19 can be performed in a network environment that supports a next-generation wireless LAN system (UHR (Ultra High Reliability) wireless LAN system or next wi-fi). The next-generation wireless LAN system is a wireless LAN system that improves upon the 802.11be system and can satisfy backward compatibility with the 802.11be system.

[0326] An example of FIG. 19 can be performed at an access point (AP). The AP can be replaced with an access point Multi-Link Device (AP MLD). The non-access point station (non-AP STA) of FIG. 19 can be replaced with a non-access point Multi-Link Device (non-AP MLD).

[0327] This embodiment proposes a method for defining an interference mitigation (IM) pilot to measure and eliminate interference coming from the Overlapping Basic Service Set (OBSS) in order to increase the reliability of signal transmission and reception between an AP and a non-AP in Next Wi-Fi (beyond 11be). Specifically, this embodiment proposes a method for deploying an IM pilot to perform interference mitigation during signal transmission and reception using a 40 MHz BW.

[0328] In step S1910, the AP (access point) generates a PPDU (Physical Protocol Data Unit).

[0329] In step S1920, the AP transmits the PPDU to a non-AP STA (non-access point station).

[0330] The above PPDU includes a data field.

[0331] The above data field includes an IM (Interference Mitigation) pilot having 0 energy.

[0332] Based on the fact that the bandwidth of the above PPDU is 40 MHz, the above IM pilot,

[0333] It is inserted at intervals of 9 indices from the first subcarrier index to the second subcarrier index, and at intervals of 9 indices from the third subcarrier index to the fourth subcarrier index.

[0334] The first subcarrier index may be -240, the second subcarrier index may be -6, the third subcarrier index may be 6, and the fourth subcarrier index may be 240. For example, the index of the subcarrier into which the IM pilot is inserted may be represented as [-240:9:-6], [6:9:240], etc. That is, when many IM pilots are defined and inserted, the pilot overhead increases, and the number of subcarriers for data transmission decreases. To compensate for this, when considering the IM pilot overhead as 10~11%, the IM pilot can be defined at intervals of 9 subcarrier units. When IM pilots are placed at intervals of 9 subcarriers, there is an effect of reducing pilot overhead compared to placing them at intervals of 4 to 6 subcarriers. Additionally, the subcarrier placement of the above IM pilot is positioned at a certain distance from the guard subcarrier and DC (Direct Current) subcarrier, which has the effect of reducing the influence of the guard subcarrier and DC subcarrier.

[0335] For example, the above IM pilot can be deployed based on a negative subcarrier index and a positive subcarrier index that form mirror symmetry.

[0336] At this time, the positive subcarrier index may be configured to have the same absolute value as the negative subcarrier index and the opposite sign.

[0337] In other words, when the IM pilot does not form mirror symmetry, implementation is easy because the IM pilot is defined using fixed subcarrier positions in units of 9 subcarriers; however, there is a disadvantage that interference measurements may be inaccurate when transmitted at low or high frequencies because the spacing between the IM pilot subcarriers from the left guard subcarrier and the right guard subcarrier is different. Therefore, by placing the IM pilot at a mirror-symmetric subcarrier index, the IM pilot defined by the negative subcarrier index centered on DC (Direct Current) is defined identically at the positive subcarrier index.

[0338] The above IM pilot may include 54 subcarriers.

[0339] The above data field may further include a CFO (Carrier Frequency Offset) pilot.

[0340] At this time, the subcarrier index of the IM pilot can be positioned so as not to overlap with the subcarrier index of the CFO pilot.

[0341] The above PPDU may be a SU (Single User) PPDU.

[0342] In addition, the above IM pilot can be used based on the data field being encoded using the LDPC (Low Density Parity Check) method.

[0343] Based on the use of the above IM pilot, the data subcarrier of the data field can be reduced. That is, the range of subcarriers constituting a 484-tone RU in a 40 MHz bandwidth can be defined by an index such as [-244:-3, 3:244], and when transmitting with the addition of the above IM pilot, a portion of the subcarriers constituting the 484-tone RU is allocated for the IM pilot, so the number of subcarriers used for data transmission can be reduced.

[0344] In this specification, the subcarrier constituting the 484-tone RU is a subcarrier that can be used for signal transmission and reception using the 484-tone RU in a 40 MHz bandwidth. A data subcarrier, an existing pilot (CFO pilot) subcarrier, or the IM pilot subcarrier may be assigned to the subcarrier constituting the 484-tone RU.

[0345] <Device Configuration>

[0346] The technical features of the specification described above may be applied to various devices and methods. For example, the technical features of the specification described above may be performed or supported through the device of FIG. 1 and / or FIG. 14. For example, the technical features of the specification described above may be applied only to parts of FIG. 1 and / or FIG. 14. For example, the technical features of the specification described above may be implemented based on the processing chip (114, 124) of FIG. 1, or based on the processor (111, 121) and memory (112, 122) of FIG. 1, or based on the processor (1410) and memory (1420) of FIG. 14. For example, the device of the specification receives a PPDU (Physical Protocol Data Unit) from a transmitting STA (station); and decodes the PPDU.

[0347] The technical features of this specification may be implemented based on a computer-readable medium (CRM). For example, the CRM proposed by this specification is at least one computer-readable medium comprising instructions based on execution by at least one processor.

[0348] The above CRM may store instructions for performing operations including the step of receiving a PPDU (Physical Protocol Data Unit) from a transmitting STA (station); and the step of decoding the PPDU. Instructions stored in the CRM of this specification may be executed by at least one processor. At least one processor associated with the CRM of this specification may be the processor (111, 121) or processing chip (114, 124) of FIG. 1, or the processor (1410) of FIG. 14. Meanwhile, the CRM of this specification may be the memory (112, 122) of FIG. 1, the memory (1420) of FIG. 14, or a separate external memory / storage medium / disk, etc.

[0349] The technical features of the present specification described above are applicable to various applications or business models. For example, the technical features described above may be applied for wireless communication in devices supporting Artificial Intelligence (AI).

[0350] Artificial intelligence refers to the field of researching artificial intelligence or the methodologies to create it, while machine learning refers to the field of researching methodologies to define and solve various problems addressed within the field of artificial intelligence. Machine learning is also defined as an algorithm that improves performance on a task through continuous experience.

[0351] An Artificial Neural Network (ANN) is a model used in machine learning that can refer to any model capable of problem-solving, composed of artificial neurons (nodes) that form a network through the connection of synapses. An artificial neural network can be defined by connection patterns between neurons in different layers, a learning process that updates model parameters, and an activation function that generates output values.

[0352] An artificial neural network may include an input layer, an output layer, and optionally one or more hidden layers. Each layer may include one or more neurons, and the artificial neural network may include synapses connecting the neurons. In an artificial neural network, each neuron may output a function value of an activation function for input signals, weights, and biases input through the synapses.

[0353] Model parameters refer to parameters determined through learning, including synaptic connection weights and neuron biases. Hyperparameters, on the other hand, refer to parameters that must be set prior to training in a machine learning algorithm, including the learning rate, number of iterations, mini-batch size, and initialization function.

[0354] The objective of training an artificial neural network can be viewed as determining model parameters that minimize the loss function. The loss function can be used as an indicator to determine optimal model parameters during the training process of an artificial neural network.

[0355] Machine learning can be classified into supervised learning, unsupervised learning, and reinforcement learning depending on the learning method.

[0356] Supervised learning refers to a method of training an artificial neural network with labels provided for the training data; a label can refer to the correct answer (or result) that the neural network must infer when the training data is input. Unsupervised learning refers to a method of training an artificial neural network without labels provided for the training data. Reinforcement learning refers to a learning method in which an agent defined within an environment is trained to select an action or sequence of actions that maximizes the cumulative reward in each state.

[0357] Machine learning implemented using a Deep Neural Network (DNN) that includes multiple hidden layers among artificial neural networks is also called Deep Learning, and Deep Learning is a part of Machine Learning. Hereinafter, Machine Learning is used in a sense that includes Deep Learning.

[0358] In addition, the aforementioned technical features can be applied to the wireless communication of robots.

[0359] A robot can refer to a machine that automatically processes or operates a given task based on its own capabilities. In particular, a robot that has the ability to perceive its environment, make decisions on its own, and perform actions can be called an intelligent robot.

[0360] Robots can be classified into industrial, medical, domestic, and military types depending on their purpose or field of use. Robots are equipped with drive units, including actuators or motors, to perform various physical movements, such as moving robot joints. Additionally, mobile robots include wheels, brakes, and propellers in their drive units, enabling them to drive on the ground or fly in the air.

[0361] In addition, the aforementioned technical features can be applied to devices that support augmented reality.

[0362] Extended Reality is a collective term for Virtual Reality (VR), Augmented Reality (AR), and Mixed Reality (MR). VR technology provides real-world objects or backgrounds solely as CG images, AR technology provides virtual CG images superimposed on real-world images, and MR technology is a computer graphics technology that mixes and combines virtual objects with the real world.

[0363] MR technology is similar to AR technology in that it displays real-world objects and virtual objects together. However, there is a difference in that while virtual objects in AR technology are used to complement real-world objects, virtual objects and real-world objects are used as equals in MR technology.

[0364] XR technology can be applied to HMDs (Head-Mount Displays), HUDs (Head-Up Displays), mobile phones, tablet PCs, laptops, desktops, TVs, digital signage, etc., and devices to which XR technology is applied can be called XR devices.

[0365] The claims described in this specification may be combined in various ways. For example, the technical features of the method claims in this specification may be combined to be implemented as a device, and the technical features of the device claims in this specification may be combined to be implemented as a method. Furthermore, the technical features of the method claims and the technical features of the device claims in this specification may be combined to be implemented as a device, and the technical features of the method claims and the technical features of the device claims in this specification may be combined to be implemented as a method.

Claims

1. In a wireless LAN system, A non-AP (non-access point) STA (station) receiving a PPDU (Physical Protocol Data Unit) from an AP (access point); and The above non-AP STA includes the step of decoding the above PPDU, wherein The above PPDU includes a data field, and The above data field includes an IM (Interference Mitigation) pilot having 0 energy, and Based on the fact that the bandwidth of the above PPDU is 40 MHz, the above IM pilot, Inserted at intervals of 9 subcarrier indices from the 1st subcarrier index to the 2nd subcarrier index, and Inserted at intervals of 9 subcarrier indices from the 3rd subcarrier index to the 4th subcarrier index, and The first subcarrier index is -240, the second subcarrier index is -6, the third subcarrier index is 6, and the fourth subcarrier index is 240. method.

2. In Paragraph 1, The above IM pilot is positioned based on a negative subcarrier index and a positive subcarrier index that form mirror symmetry, and The above positive subcarrier index is configured to have the same absolute value as the above negative subcarrier index and the opposite sign. method.

3. In Paragraph 1, The number of subcarriers included in the above IM pilot is 54. method.

4. In Paragraph 1, The above data field further includes a CFO (Carrier Frequency Offset) pilot, and The subcarrier index of the above IM pilot does not overlap with the subcarrier index of the above CFO pilot method.

5. In Paragraph 1, The above PPDU is a SU (Single User) PPDU method.

6. In Paragraph 1, The above IM pilot is used based on the fact that the data field is encoded using the LDPC (Low Density Parity Check) method, and Based on the use of the above IM pilot, the data subcarrier of the above data field is reduced method 7. In a wireless LAN system, a non-AP (non-access point) STA (station) is, Memory; transceiver; and The processor comprises the memory and the transceiver, operably coupled thereto, wherein the processor comprises: Receive a PPDU (Physical Protocol Data Unit) from an AP (access point); and Decode the above PPDU, The above PPDU includes a data field, and The above data field includes an IM (Interference Mitigation) pilot having 0 energy, and Based on the fact that the bandwidth of the above PPDU is 40 MHz, the above IM pilot, Inserted at intervals of 9 subcarrier indices from the 1st subcarrier index to the 2nd subcarrier index, and Inserted at intervals of 9 subcarrier indices from the 3rd subcarrier index to the 4th subcarrier index, and The first subcarrier index is -240, the second subcarrier index is -6, the third subcarrier index is 6, and the fourth subcarrier index is 240. non-AP STA.

8. In a wireless LAN system, A step in which an AP (access point) generates a PPDU (Physical Protocol Data Unit); and The above AP includes the step of transmitting the PPDU to a non-AP (non-access point) STA (station), The above PPDU includes a data field, and The above data field includes an IM (Interference Mitigation) pilot having 0 energy, and Based on the fact that the bandwidth of the above PPDU is 40 MHz, the above IM pilot, Inserted at intervals of 9 subcarrier indices from the 1st subcarrier index to the 2nd subcarrier index, and Inserted at intervals of 9 subcarrier indices from the 3rd subcarrier index to the 4th subcarrier index, and The first subcarrier index is -240, the second subcarrier index is -6, the third subcarrier index is 6, and the fourth subcarrier index is 240. method.

9. In Paragraph 8, The above IM pilot is positioned based on a negative subcarrier index and a positive subcarrier index that form mirror symmetry, and The above positive subcarrier index is configured to have the same absolute value as the above negative subcarrier index and the opposite sign. method.

10. In Paragraph 8, The number of subcarriers included in the above IM pilot is 54. method.

11. In Paragraph 8, The above data field further includes a CFO (Carrier Frequency Offset) pilot, and The subcarrier index of the above IM pilot does not overlap with the subcarrier index of the above CFO pilot method.

12. In Paragraph 8, The above PPDU is a SU (Single User) PPDU method.

13. In Paragraph 8, The above IM pilot is used based on the fact that the data field is encoded using the LDPC (Low Density Parity Check) method, and Based on the use of the above IM pilot, the data subcarrier of the above data field is reduced method 14. In a wireless LAN system, an AP (access point) is, Memory; transceiver; and The processor comprises the memory and the transceiver, operably coupled thereto, wherein the processor comprises: Generate a PPDU (Physical Protocol Data Unit); and Transmit the above PPDU to a non-AP (non-access point) STA (station), The above PPDU includes a data field, and The above data field includes an IM (Interference Mitigation) pilot having 0 energy, and Based on the fact that the bandwidth of the above PPDU is 40 MHz, the above IM pilot, Inserted at intervals of 9 subcarrier indices from the 1st subcarrier index to the 2nd subcarrier index, and Inserted at intervals of 9 subcarrier indices from the 3rd subcarrier index to the 4th subcarrier index, and The first subcarrier index is -240, the second subcarrier index is -6, the third subcarrier index is 6, and the fourth subcarrier index is 240. AP.

15. At least one computer-readable medium comprising an instruction based on execution by at least one processor, A step of receiving a PPDU (Physical Protocol Data Unit) from an AP (access point); and The step of decoding the above PPDU is included, The above PPDU includes a data field, and The above data field includes an IM (Interference Mitigation) pilot having 0 energy, and Based on the fact that the bandwidth of the above PPDU is 40 MHz, the above IM pilot, Inserted at intervals of 9 subcarrier indices from the 1st subcarrier index to the 2nd subcarrier index, and Inserted at intervals of 9 subcarrier indices from the 3rd subcarrier index to the 4th subcarrier index, and The first subcarrier index is -240, the second subcarrier index is -6, the third subcarrier index is 6, and the fourth subcarrier index is 240. Recording media.

16. In a device in a wireless LAN system, Memory; and The processor comprises the above memory and operablely coupled thereto, wherein the processor is: Receive a PPDU (Physical Protocol Data Unit) from an AP (access point); and Decode the above PPDU, The above PPDU includes a data field, and The above data field includes an IM (Interference Mitigation) pilot having 0 energy, and Based on the fact that the bandwidth of the above PPDU is 40 MHz, the above IM pilot, Inserted at intervals of 9 subcarrier indices from the 1st subcarrier index to the 2nd subcarrier index, and Inserted at intervals of 9 subcarrier indices from the 3rd subcarrier index to the 4th subcarrier index, and The first subcarrier index is -240, the second subcarrier index is -6, the third subcarrier index is 6, and the fourth subcarrier index is 240. device.

Images