Method and device for performing sounding protocol for applying beamforming during application of spatial modulation in wireless LAN system

Abstract

Proposed are a method and device for performing a sounding protocol for applying beamforming during the application of spatial modulation in a wireless LAN system. Specifically, a reception STA receives an NDPA frame from a transmission STA. The reception STA receives an NDP frame from the transmission STA. The reception STA transmits a feedback frame to the transmission STA. The NDPA frame includes first to third fields. The first field includes information about whether beamforming for spatial modulation is indicated. The second field includes information about a modulation order of the spatial modulation. The third field includes information about the number of activated antenna elements for spatial modulation.

Description

Method and device for performing a sounding protocol for applying beamforming when applying spatial modulation in a wireless LAN system

[0001] This specification relates to a technique for performing a sounding protocol for applying beamforming when applying spatial modulation in a wireless LAN system, and more specifically, to a method and device for performing beamforming to which spatial modulation is applied by configuring an NDPA frame and a compressed beamforming / CQI frame.

[0002] Wireless local area networks (WLANs) have been improved in various ways. For example, the IEEE 802.11ax standard proposed an improved communication environment using orthogonal frequency division multiple access (OFDMA) and downlink multi-user multiple input, multiple output (DL MU MIMO) techniques.

[0003] This specification proposes technical features that can be utilized in a new communications standard. For example, the new communications standard could be the Extreme High Throughput (EHT) standard, which is currently under discussion. The EHT standard could utilize newly proposed increased bandwidth, an improved PHY layer protocol data unit (PPDU) structure, improved sequences, and the Hybrid Automatic Repeat Request (HARQ) technique. The EHT standard could also be referred to as the IEEE 802.11be standard.

[0004] New wireless LAN standards may allow for an increased number of spatial streams. This may necessitate improvements to signaling techniques within the wireless LAN system to properly utilize these increased spatial streams.

[0005] This specification proposes a method and device for performing a sounding protocol for applying beamforming when applying spatial modulation in a wireless LAN system.

[0006] An example of this specification proposes a method for performing a sounding protocol for applying beamforming when applying spatial modulation.

[0007] The present 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 the 802.11be system and can satisfy backward compatibility with the 802.11be system.

[0008] The present embodiment is performed in a receiving STA, and the receiving STA may correspond to at least one STA (station) or beamformer. The transmitting STA may correspond to an AP (access point) or beamformer.

[0009] This embodiment proposes a method for performing beamforming by applying spatial modulation, a technique for increasing transmission rate by informing whether a specific antenna is on or off. In particular, this specification proposes a signaling method for feeding back all component V matrices.

[0010] A receiving STA (station) receives an NDPA (Null Data Packet Announcement) frame from a transmitting STA.

[0011] The above receiving STA receives an NDP frame from the above transmitting STA.

[0012] The receiving STA transmits a feedback frame to the transmitting STA.

[0013] The above NDPA frame includes first to third fields.

[0014] The first field includes information on whether beamforming for spatial modulation is indicated. For example, if the first field is set to 1, it may indicate that spatial modulation is applied. If the first field is set to 0, it may indicate that spatial modulation is not applied.

[0015] The second field includes information about the modulation order of the spatial modulation. The modulation order of the spatial modulation may be determined based on the number of transmission antennas of the transmitting STA and the number of activated antenna elements described below. The spatial modulation may be a technology that secures a transmission stream through activated antenna elements by information about whether the transmission antennas are on or off, thereby increasing the transmission rate.

[0016] The third field includes information about the number of activated antenna elements for spatial modulation. Based on the third field, the dimension of the beamforming matrix fed back by the beamformer can be specified.

[0017] The present embodiment proposes a sounding feedback mechanism that enables a beamformer / beamformee that wishes to apply the above spatial modulation to obtain an appropriate beamforming matrix. To this end, a signaling method is proposed for feeding back all element V matrices by modifying the NDPA frame and the feedback frame (or compressed beamforming / Channel Quality Indicator (CQI) frame) in the existing sounding feedback mechanism. This has the effect of obtaining beamforming gain even when operating the above spatial modulation, thereby improving the overall system throughput.

[0018] Figure 1 illustrates an example of a transmitting device and / or a receiving device of the present specification.

[0019] Figure 2 is a conceptual diagram showing the structure of a wireless local area network (WLAN).

[0020] Figure 3 is a diagram illustrating a general link setup process.

[0021] Figure 4 illustrates one embodiment of a multi-link (ML).

[0022] FIG. 5 illustrates a PPDU (physical protocol data unit or physical layer (PHY) protocol data unit) transmitted / received by an STA of this specification.

[0023] Figure 6 is a diagram showing the layout of resource units (RUs) used for 20MHz PPDU.

[0024] Figure 7 is a diagram showing the layout of resource units (RUs) used for 40MHz PPDU.

[0025] Figure 8 is a diagram showing the layout of resource units (RUs) used for 80MHz PPDU.

[0026] Figure 9 shows the operation according to UL-MU.

[0027] Figure 10 shows an example of channels used / supported / defined within the 2.4 GHz band.

[0028] Figure 11 illustrates an example of channels used / supported / defined within the 5 GHz band.

[0029] Figure 12 illustrates an example of channels used / supported / defined within the 6 GHz band.

[0030] Figure 13 shows an example of a header of a MAC frame.

[0031] FIG. 14 illustrates a modified example of a transmitting device and / or a receiving device of the present specification.

[0032] Figure 15 shows an example of EHT non-TB sounding.

[0033] Figure 16 shows an example of EHT TB sounding.

[0034] Figure 17 shows an example of the EHT NDP Announcement frame format.

[0035] Figure 18 illustrates an example block diagram of a TX device implementing spatial modulation.

[0036] Figure 19 illustrates an example of the sounding feedback mechanism proposed in this specification.

[0037] Figure 20 illustrates an example of the STA Info field of NDPA proposed in this specification.

[0038] Figure 21 illustrates another example of the STA Info field of NDPA proposed in this specification.

[0039] Figure 22 illustrates an example of the MIMO control field proposed in this specification.

[0040] Figure 23 illustrates an example of a spatial modulation based compressed beamforming report proposed in this specification.

[0041] Figure 24 illustrates another example of the MIMO control field proposed in this specification.

[0042] Figure 25 illustrates another example of a spatial modulation based compressed beamforming report proposed in this specification.

[0043] Figure 26 illustrates an example of a PPDU of this specification.

[0044] Figure 27 illustrates a procedure for a transmitting device according to the present embodiment to perform a sounding protocol for applying spatial modulation.

[0045] Figure 28 illustrates a procedure for a receiving device according to the present embodiment to perform a sounding protocol for applying spatial modulation.

[0046] Figure 29 illustrates the overall procedure of a sounding protocol for applying spatial modulation according to the present embodiment.

[0047] Figure 30 is a flowchart illustrating the operation of a transmitting device according to the present embodiment.

[0048] Figure 31 is a flowchart illustrating the operation of a receiving device according to the present embodiment.

[0049] FIG. 32 is a flowchart illustrating a procedure for performing a sounding protocol for applying beamforming when a transmitting STA according to the present embodiment applies spatial modulation.

[0050] FIG. 33 is a flowchart illustrating a procedure for performing a sounding protocol for applying beamforming when a receiving STA according to the present embodiment applies spatial modulation.

[0051] In this specification, “A or B” can mean “only A,” “only B,” or “both A and B.” In other words, “A or B” in this specification can be interpreted as “A and / or B.” For example, “A, B or C” in this specification can mean “only A,” “only B,” “only C,” or “any combination of A, B, and C.”

[0052] As used herein, a slash ( / ) or a comma can mean "and / or." For example, "A / B" can mean "and / or B." Accordingly, "A / B" can mean "only A," "only B," or "both A and B." For example, "A, B, C" can mean "A, B, or C."

[0053] In this specification, “at least one of A and B” can 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” can be interpreted identically to “at least one of A and B.”

[0054] In addition, parentheses used in this specification may mean “for example.” Specifically, when “control information (UHR-Signal field)” is indicated, the “UHR-Signal field” may be suggested as an example of “control information.” In other words, the “control information” in this specification is not limited to the “UHR-Signal field,” and the “UHR-Signal field” may be suggested as an example of “control information.” In addition, even when indicated as “control information (UHR-Signal field),” the “UHR-Signal field” may be suggested as an example of “control information.”

[0055] Additionally, as used herein, “a / an” can mean “at least one” or “one or more.” Additionally, terms ending in “(s)” can mean “at least one” or “one or more.”

[0056] Additionally, the expressions “based on” or “on the basis of” or “according to” used herein mean “based at least in part on” and not “based solely on.”

[0057] Technical features individually described in a single drawing in this specification may be implemented individually or simultaneously.

[0058] The following examples of this specification can be applied to various wireless communication systems. For example, the following examples of this specification can be applied to wireless local area network (WLAN) systems. For example, the present specification can be applied to the IEEE 802.11a / g / n / ac / ax / be / bn standards. In addition, the examples of this specification can be applied to the Ultra High Reliability (UHR) standard or the next-generation wireless LAN standard that enhances IEEE 802.11bn. In addition, the examples of this specification can be applied to mobile communication systems. For example, the examples of this specification can be applied to mobile communication systems based on Long Term Evolution (LTE) and its evolution based on the 3rd Generation Partnership Project (3GPP) standard.

[0059] In order to explain the technical features of this specification, the technical features to which this specification can be applied are described below.

[0060] Figure 1 illustrates an example of a transmitting device and / or a receiving device of the present specification.

[0061] 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 the present specification may also be referred to by various names such as a mobile terminal, a wireless device, a Wireless Transmit / Receive Unit (WTRU), a User Equipment (UE), a Mobile Station (MS), a Mobile Subscriber Unit, or simply a user. The STA (110, 120) of the present specification may also be referred to by various names such as a network, a base station, a Node-B, an access point (AP), a repeater, a router, a relay, etc. The STA (110, 120) of the present specification may also be referred to by various names such as a receiving apparatus, a transmitting apparatus, a receiving STA, a transmitting STA, a receiving device, a transmitting device, etc.

[0062] For example, STA (110, 120) may perform the role of an AP (access point) or a non-AP role. That is, STA (110, 120) of the present specification may perform the functions of an AP and / or a non-AP. In the present specification, AP may also be indicated as an AP STA.

[0063] The STA (110, 120) of this specification can support various communication standards other than the IEEE 802.11 standard. For example, it can support communication standards according to the 3GPP standard (e.g., LTE, LTE-A, 5G NR standard). In addition, the STA of this specification can be implemented in various devices such as mobile phones, vehicles, and personal computers. In addition, the STA of this specification can support communication for various communication services such as voice calls, video calls, data communications, and autonomous driving (Self-Driving, Autonomous-Driving).

[0064] In this specification, STA (110, 120) may include a medium access control (MAC) and a physical layer interface for a wireless medium that follow the provisions of the IEEE 802.11 standard.

[0065] Based on the sub-drawing (a) of Fig. 1, STA (110, 120) is described as follows.

[0066] The first STA (110) may include a processor (111), a 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.

[0067] The transceiver (113) of the first STA performs signal transmission and reception operations. Specifically, it can transmit and receive IEEE 802.11 packets (e.g., IEEE 802.11a / b / g / n / ac / ax / be, etc.).

[0068] 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 transmission signal, and perform control for signal transmission. The memory (112) of the AP can store a signal received through the transceiver (113) (i.e., a reception signal) and store a signal to be transmitted through the transceiver (i.e., a transmission signal).

[0069] For example, the second STA (120) can perform the intended operation of a non-AP STA. For example, the transceiver (123) of the non-AP performs signal transmission and reception operations. Specifically, it can transmit and receive IEEE 802.11 packets (e.g., IEEE 802.11a / b / g / n / ac / ax / be, etc.).

[0070] For example, the processor (121) of the Non-AP STA can receive a signal through the transceiver (123), process the received signal, generate a transmission signal, and perform control for signal transmission. The memory (122) of the Non-AP STA can store a signal received through the transceiver (123) (i.e., a reception signal) and store a signal to be transmitted through the transceiver (i.e., a transmission signal).

[0071] For example, in the specification below, the operation of a device indicated as AP may be performed in the first STA (110) or the second STA (120). For example, if the first STA (110) is an AP, the operation of the device indicated as AP may be controlled by the processor (111) of the first STA (110), and a related signal may be transmitted or received through a transceiver (113) controlled by the processor (111) of the first STA (110). In addition, control information related to the operation of the AP or a transmission / reception signal of the AP may be stored in the memory (112) of the first STA (110). In addition, when the second STA (110) is an AP, the operation of the device indicated as an AP is controlled by the processor (121) of the second STA (120), and a related signal can 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 signal of the AP can be stored in the memory (122) of the second STA (110).

[0072] For example, in the specification below, the operation of a device indicated as a non-AP (or User-STA) may be performed in the STA (110) or the second STA (120). For example, if the second STA (120) is a non-AP, the operation of the device indicated as a non-AP may be controlled by the processor (121) of the second STA (120), and a related signal 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 non-AP or the transmission / reception signal 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 a device indicated as a non-AP is controlled by the processor (111) of the first STA (110), and a related signal may be transmitted or received through a transceiver (113) controlled by the processor (111) of the first STA (120). In addition, control information related to the operation of the non-AP or the transmission / reception signal of the AP may be stored in the memory (112) of the first STA (110).

[0073] In the following specification, devices called (transmitting / receiving) STA, first STA, second STA, STA1, STA2, AP, first AP, second AP, AP1, AP2, (transmitting / receiving) Terminal, (transmitting / receiving) device, (transmitting / receiving) apparatus, network, etc. may refer to the STA (110, 120) of FIG. 1. For example, devices indicated as (transmitting / receiving) STA, first STA, second STA, STA1, STA2, AP, first AP, second AP, AP1, AP2, (transmitting / receiving) Terminal, (transmitting / receiving) device, (transmitting / receiving) apparatus, network, etc. without specific drawing symbols may also refer to the STA (110, 120) of FIG. 1. For example, in the example below, the operation of various STAs transmitting and receiving signals (e.g., PPPDU) may be performed by the transceiver (113, 123) of FIG. 1. In addition, in the example below, 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 that generates a transmission / reception signal or performs data processing or operation in advance for a transmission / reception signal may include 1) an operation of determining / obtaining / configuring / computing / decoding / encoding bit information of a subfield (SIG, STF, LTF, Data) field included in a PPDU, 2) an operation of determining / configuring / obtaining time resources or frequency resources (e.g., subcarrier resources) used for a subfield (SIG, STF, LTF, Data) field included in a PPDU, 3) an operation of determining / configuring / obtaining a specific sequence (e.g., a pilot sequence, an STF / LTF sequence, an extra sequence applied to SIG) used for a subfield (SIG, STF, LTF, Data) field included in a PPDU, 4) a power control operation and / or a power saving operation applied to an STA, 5) an operation related to determining / obtaining / configuring / computing / decoding / encoding an ACK signal, etc. Additionally, in the examples below, various information (e.g., information related to fields / subfields / control fields / parameters / power, etc.) used by various STAs for determining / acquiring / configuring / computing / decoding / encoding transmission / reception signals can be stored in the memory (112, 122) of FIG. 1.

[0074] The device / STA of the sub-drawing (a) of the above-described FIG. 1 can be modified as in the sub-drawing (b) of FIG. 1. Hereinafter, the STA (110, 120) of the present specification will be described based on the sub-drawing (b) of FIG. 1.

[0075] For example, the transceiver (113, 123) illustrated in sub-drawing (b) of FIG. 1 may perform the same function as the transceiver illustrated in sub-drawing (a) of FIG. 1 described above. For example, the processing chip (114, 124) illustrated in sub-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) illustrated in sub-drawing (b) of FIG. 1 may perform the same function as the processor (111, 121) and the memory (112, 122) illustrated in sub-drawing (a) of FIG. 1 described above.

[0076] 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, Access Point (AP), 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) illustrated in the sub-drawings (a) / (b) of FIG. 1, or may refer to the processing chip (114, 124) illustrated in the sub-drawing (b) of FIG. 1. That is, the technical feature of the present specification may be performed in the STA (110, 120) illustrated in the sub-drawings (a) / (b) of FIG. 1, or may be performed only in the processing chip (114, 124) illustrated in the sub-drawings (b) of FIG. 1. For example, the technical feature that the transmitting STA transmits a control signal may be understood as a technical feature that the control signal generated in the processor (111, 121) illustrated in the sub-drawings (a) / (b) of FIG. 1 is transmitted through the transceiver (113, 123) illustrated in the sub-drawings (a) / (b) of FIG. 1. Alternatively, the technical feature that the transmitting STA transmits a control signal may be understood as a technical feature that the control signal to be transmitted to the transceiver (113, 123) is generated in the processing chip (114, 124) illustrated in the sub-drawings (b) of FIG. 1.

[0077] For example, the technical feature of a receiving STA receiving a control signal can be understood as a technical feature of a control signal being received by a transceiver (113, 123) illustrated in sub-drawing (a) of FIG. 1. Alternatively, the technical feature of a receiving STA receiving a control signal can be understood as a technical feature of a control signal received by a transceiver (113, 123) illustrated in sub-drawing (a) of FIG. 1 being acquired by a processor (111, 121) illustrated in sub-drawing (a) of FIG. 1. Alternatively, the technical feature of a receiving STA receiving a control signal can be understood as a technical feature of a control signal received by a transceiver (113, 123) illustrated in sub-drawing (b) of FIG. 1 being acquired by a processing chip (114, 124) illustrated in sub-drawing (b) of FIG.

[0078] Referring to the sub-drawing (b) of FIG. 1, software code (115, 125) may be included in the 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.

[0079] The processor (111, 121) or processing chip (114, 124) illustrated in FIG. 1 may include an application-specific integrated circuit (ASIC), another chipset, a logic circuit, and / or a data processing device. 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 an enhanced processor thereof.

[0080] In this specification, uplink may mean a link for communication from a non-AP STA to an AP STA, and uplink PPDU / packet / signal, etc. may be transmitted through the uplink. In addition, in this specification, downlink may mean a link for communication from an AP STA to a non-AP STA, and downlink PPDU / packet / signal, etc. may be transmitted through the downlink.

[0081] Figure 2 is a conceptual diagram showing the structure of a wireless local area network (WLAN).

[0082] The upper part of Figure 2 shows the structure of the infrastructure BSS (basic service set) of IEEE (institute of electrical and electronic engineers) 802.11.

[0083] The upper part of Figure 2 shows the structure of the infrastructure BSS (basic service set) of IEEE (institute of electrical and electronic engineers) 802.11.

[0084] Referring to the top of FIG. 2, the wireless LAN system may include one or more infrastructure BSSs (200, 205) (hereinafter, BSS). The BSSs (200, 205) are a collection of APs and STAs, such as an access point (AP) 225 and a station (STA1, 200-1), that have successfully synchronized and can communicate with each other, and are not a concept that designates a specific area. The BSS (205) may also include one or more STAs (205-1, 205-2) that can be associated with one AP (230).

[0085] A BSS may include at least one STA, an AP (225, 230) providing a distribution service, and a distribution system (DS, 210) connecting multiple APs.

[0086] A distributed system (210) can connect multiple BSSs (200, 205) to implement an extended service set (ESS, 240). An ESS (240) can be used as a term to indicate a network formed by connecting one or more APs through the distributed system (210). APs included in a single ESS (240) can have the same SSID (service set identification).

[0087] The portal (portal, 220) can act as a bridge to connect a wireless LAN network (IEEE 802.11) to another network (e.g., 802.X).

[0088] In a BSS such as the upper part 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 and perform communication between STAs without an AP (225, 230). A network that establishes a network and performs communication between STAs without an AP (225, 230) is defined as an ad-hoc network or an independent basic service set (IBSS).

[0089] The bottom of Figure 2 is a conceptual diagram showing IBSS.

[0090] 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 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 access to the distributed system is not permitted, forming a self-contained network.

[0091] Figure 3 is a diagram illustrating a general link setup process.

[0092] In step S310, the STA may perform a network discovery operation. This network discovery operation may include scanning by the STA. That is, for the STA to access the network, it must find a network it can join. Before joining a wireless network, the STA must identify compatible networks. The process of identifying networks in a specific area is called scanning. Scanning methods include active scanning and passive scanning.

[0093] Figure 3 illustrates a network discovery operation that includes an active scanning process as an example. In active scanning, an STA performing scanning transmits a probe request frame to discover which APs exist in the vicinity while moving between channels and waits for a response. A responder transmits a probe response frame to the STA that transmitted the probe request frame in response to the probe request frame. Here, the responder may be the STA that last transmitted a beacon frame in the BSS of the channel being scanned. In a BSS, the AP transmits the beacon frame, so the AP becomes the responder. In an IBSS, the STAs within the IBSS take turns transmitting beacon frames, so the responder is not constant. For example, an STA that transmits a probe request frame on channel 1 and receives a probe response frame on channel 1 can store BSS-related information included in the received probe response frame and move to the next channel (e.g., channel 2) to perform scanning (i.e., transmitting and receiving probe requests / responses on channel 2) in the same manner.

[0094] Although not shown in the example of FIG. 3, the scanning operation can also be performed in a passive scanning manner. An STA performing scanning based on passive scanning can wait for a beacon frame while moving between channels. A beacon frame is one of the management frames in IEEE 802.11. It announces the presence of a wireless network and is periodically transmitted so that the scanning STA can find the wireless network and participate in the wireless network. In the BSS, the AP periodically transmits the beacon frame, and in the IBSS, the STAs within the IBSS take turns transmitting the beacon frame. When the scanning STA receives a beacon frame, it stores the information about the BSS included in the beacon frame and moves to another channel, recording the beacon frame information on each channel. An STA that receives a beacon frame can store the BSS-related information included in the received beacon frame, move to the next channel, and perform scanning on the next channel in the same manner.

[0095] An STA that discovers a 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 below. The authentication process of S320 may include a process in which the STA transmits an authentication request frame to the AP, and the AP responds by transmitting an authentication response frame to the STA. The authentication frame used for the authentication request / response corresponds to a management frame.

[0096] The authentication frame may include information such as an authentication algorithm number, an authentication transaction sequence number, a status code, a challenge text, a Robust Security Network (RSN), and a Finite Cyclic Group.

[0097] An STA can transmit an authentication request frame to an AP. The AP can determine whether to grant authentication to the STA based on the information contained in the received authentication request frame. The AP can provide the result of the authentication process to the STA via an authentication response frame.

[0098] A successfully authenticated STA may perform an association process based on step S330. The association process includes a process in which the STA transmits an association request frame to the AP, and the AP transmits an association response frame to the STA in response. For example, the association request frame may include information related to various capabilities, such as a beacon listen interval, a service set identifier (SSID), supported rates, supported channels, RSN, mobility domain, supported operating classes, a Traffic Indication Map Broadcast request, and interworking service capabilities. For example, the association response frame may contain information related to various capabilities, status codes, Association ID (AID), supported rates, Enhanced Distributed Channel Access (EDCA) parameter sets, Received Channel Power Indicator (RCPI), Received Signal to Noise Indicator (RSNI), mobility domains, timeout interval (association comeback time), overlapping BSS scan parameters, TIM broadcast response, QoS maps, etc.

[0099] 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 four-way handshaking using an Extensible Authentication Protocol over LAN (EAPOL) frame.

[0100] Figure 4 illustrates one embodiment of a multi-link (ML).

[0101] As illustrated in FIG. 4, multiple multi-link devices (MLDs) can communicate over a remote link. The MLDs can be categorized into AP MLDs including multiple AP STAs and non-AP MLDs including multiple non-AP STAs. That is, the AP MLD can include affiliated APs (i.e., AP STAs), and the non-AP MLD can include affiliated STAs (i.e., non-AP STAs, or user-STAs).

[0102] A multilink may include a first link and a second link, and different channels / subchannels / frequency resources may be allocated to the first and second links. The first and second multilinks may be identified through 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 second link may be configured in different bands.

[0103] The AP MLD of FIG. 4 includes three affiliated APs. In the 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 the 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. Furthermore, in the 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. Furthermore, in the 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.

[0104] In the example of FIG. 4, AP1 may initiate a multi-link setup procedure (ML setup procedure) by transmitting an Association Request frame to non-AP STA1. In the example of FIG. 4, non-AP STA1 may transmit an Association Response frame in response to the Association Request frame. Each AP (e.g., AP1 / 2 / 3) illustrated in FIG. 4 may be identical to the AP illustrated in FIG. 1 and / or FIG. 2, and each non-AP (e.g., non-AP1 / 2 / 3) illustrated in FIG. 4 may be identical to the STA (i.e., user-STA or non-AP STA) illustrated in FIG. 1 and / or FIG. 2.

[0105] 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.

[0106] FIG. 5 illustrates a PPDU (physical protocol data unit or physical layer (PHY) protocol data unit) transmitted / received by an STA of this specification.

[0107] The STA (e.g., AP STA, non-AP STA, AP MLD, non-AP MLD) of the present specification can transmit and / or receive the PPDU of FIG. 5. The PPDU described in the present specification may have, for example, the structure of FIG. 5. In addition, the PPDU described in the present specification may be called by various names such as a transmission PPDU, a reception PPDU, a first type PPDU, or an Nth type PPDU, etc. The PPDU described in the present specification can be used in a WLAN system defined according to IEEE 802.11bn and / or a next-generation WLAN system that improves IEEE 802.11bn.

[0108] 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 a single-user (SU) mode / type / transmission, a multi-user (MU) mode / type / transmission, and a null data packet (NDP) mode / type / transmission related to channel sounding. For example, if the example of FIG. 5 is related to NDP, the Data field illustrated may be omitted. If the PPDU of FIG. 5 is used for a trigger-based (TB) mode, the UHR-SIG of FIG. 5 may be omitted. In other words, an STA that has received a trigger frame for UL-MU (Uplink-MU) communication may transmit a PPDU with the UHR-SIG omitted in the example of FIG. 5.

[0109] In FIG. 5, L-STF or UHR-LTF may be called a preamble or physical preamble, and may be generated / transmitted / received / acquired / decoded in the physical layer (included in the transmitting / receiving STA).

[0110] Each block illustrated in Fig. 5 may be called a field / subfield / signal, etc. The names of these fields / subfields / signals may be, as illustrated in Fig. 5, 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.

[0111] The subcarrier spacing of the L-STF, L-LTF, L-SIG, RL-SIG, U-SIG, and UHR-SIG fields in FIG. 5 may be set to 312.5 kHz, and the subcarrier spacing of the UHR-STF, UHR-LTF, and Data fields may 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 may be expressed in units of 312.5 kHz, and the tone index (or subcarrier index) of the UHR-STF, UHR-LTF, and Data fields may be expressed in units of 78.125 kHz.

[0112] In the PPDU of Fig. 5, L-LTF and L-STF may be identical to conventional fields (e.g., non-HT LTF and non-HT STF defined in conventional WLAN standards).

[0113] The L-SIG field of FIG. 5 may include, 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 include information about the length or time duration of the PPDU. For example, the value of the 12 bit Length field may be determined based on the type of the PPDU. For example, 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 UHR PPDU, the value of the Length field may be determined as a multiple of 3. For example, if the PPDU is a 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, 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 an UHR PPDU is set to a value satisfying the condition that the remainder is zero when LENGTH is divided by 3.

[0114] For example, (non-AP and AP) STAs can apply BCC encoding based on a code rate of 1 / 2 to the 24 bits of information in the L-SIG field. Then, the transmitting STA can obtain 48 BCC coded bits. BPSK modulation can be applied to the 48 coded bits to generate 48 BPSK symbols. The transmitting STA can map the 48 BPSK symbols to positions excluding the pilot subcarriers {subcarrier index -21, -7, +7, +21} and the DC subcarrier {subcarrier index 0}. As a result, 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 {-1, -1, -1, 1} to the subcarrier indices {-28, -27, +27, +28}. The above signal can be used for channel estimation for the frequency domain corresponding to {-28, -27, +27, +28}.

[0115] For example, (non-AP and AP) STA can generate RL-SIG, which is generated in the same manner as L-SIG. BPSK modulation can be applied to RL-SIG. Receiving (non-AP and AP) STA can determine whether the received PPDU is a HE PPDU, EHT PPDU, or UHR PPDU based on the presence of RL-SIG. In other words, if RL-SIG is present, receiving (non-AP and AP) STA can determine whether the received PPDU is one of HE PPDU, EHT PPDU, or UHR PPDU. In other words, if RL-SIG is not present, receiving (non-AP and AP) STA can determine whether the received PPDU is one of non-HT PPDU, HT PPDU, or VHT PPDU. 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.

[0116] After the RL-SIG in Fig. 5, a U-SIG (Universal SIG) may be inserted. The U-SIG may be called by various names such as the first SIG field, the first SIG, the first type SIG, the control signal, the control signal field, the first (type) control signal, the common control field, and the common control signal.

[0117] A U-SIG can contain N bits of information and can include information for identifying the type of EHT PPDU. For example, a U-SIG can be formed based on two symbols (e.g., two consecutive OFDM symbols). Each symbol (e.g., an OFDM symbol) for a U-SIG can have a duration of 4 microseconds. Each symbol of a U-SIG can be used to transmit 26 bits of information. For example, each symbol of a U-SIG can be transmitted and received based on 52 data tones and 4 pilot tones.

[0118] For example, A bit information (e.g., 52 uncoded bits) can be transmitted through U-SIG, and the first symbol of U-SIG can transmit the first X bits of information (e.g., 26 uncoded bits) out of the total A bit information, and the second symbol of U-SIG can transmit the remaining Y bits of information (e.g., 26 uncoded bits) out of the total A bit information. For example, the transmitting STA can obtain 26 uncoded bits included in each U-SIG symbol. The transmitting STA can perform convolutional encoding (i.e., BCC encoding) based on a rate of R=1 / 2 to generate 52 coded bits, and perform interleaving on the 52 coded bits. The transmitting STA can perform BPSK modulation on the interleaved 52 coded bits to generate 52 BPSK symbols allocated to each U-SIG symbol. 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. The 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.

[0119] For example, A bit information (e.g., 52 uncoded bits) transmitted by U-SIG may include a CRC field (e.g., a 4-bit long field) and a tail field (e.g., a 6-bit long field). The CRC field and the tail field may be transmitted through the second symbol of the U-SIG. The CRC field may be generated based on 26 bits allocated to the first symbol of the U-SIG and the remaining 16 bits excluding the CRC / tail field within the second symbol, and may be generated based on a conventional CRC calculation algorithm. In addition, the tail field may be used to terminate the trellis of the convolutional decoder and may be set to, for example, "000000".

[0120] The A bit information (e.g., 52 uncoded bits) transmitted by the 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 can be assigned only to the first symbol of the U-SIG, or the version-independent bits can be assigned to both the first symbol and the second symbol of the U-SIG. For example, the version-independent bits and the version-dependent bits can be called by various names, such as the first control bit and the second control bit.

[0121] For example, the version-independent bits of the 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 (e.g., a value of 000) of the 3-bit PHY version identifier may indicate that the transmitted and received PPDU is an EHT PPDU. In addition, a second value (e.g., a value of 001) of the 3-bit PHY version identifier may indicate that the transmitted and received PPDU is an UHR PPDU.

[0122] In other words, when the (AP / non-AP) STA transmits an EHT PPDU, it can set the 3-bit PHY version identifier to the first value. In other words, the 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 an UHR PPDU based on the PHY version identifier having the second value.

[0123] 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 relates to UL communication, and the second value of the UL / DL flag field relates to DL communication.

[0124] For example, the version-independent bits of U-SIG may include information about the length of a transmission opportunity (TXOP) and information about the BSS color ID.

[0125] For example, if a UHR PPDU is classified into various types (e.g., a type related to SU transmission (performed based on UL or DL), a type related to DL transmission, a type related to NDP transmission, a type related to DL non-MU-MIMO, a type related to DL MU-MIMO, a type related to Multi-AP operation, a type related to CBF (Coordinated beamforming), SR (Spatial Reuse), a type related to C-OFDMA (Coordinated OFDMA), a type related to C-TDMA (Coordinated TDMA)), information about the type of the EHT PPDU (e.g., 2-bit or 3-bit information) can be included in the version-dependent bits of the U-SIG.

[0126] For example, a U-SIG may include information about 1) a bandwidth field including information about a bandwidth, 2) a field including information about an MCS technique applied to the UHR-SIG, 3) an indication field including information about whether a dual subcarrier modulation (DCM) technique is applied to the UHR-SIG, 4) a field including information about the number of symbols used for the UHR-SIG, 5) a field including information about whether the UHR-SIG is generated over the entire band, 6) a field including information about the type of UHR-LTF / STF, and 7) a field indicating the length of the UHR-LTF and the CP length.

[0127] Preamble puncturing may be applied to the PPDU of FIG. 5. Preamble puncturing refers to applying puncturing to a portion of the entire bandwidth of the PPDU (e.g., the 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.

[0128] For example, the pattern of preamble puncturing can be preset. For example, when the first puncturing pattern is applied, puncturing can be applied only to the secondary 20 MHz band within the 80 MHz band. For example, when the second puncturing pattern is applied, puncturing can be applied only to one of the two secondary 20 MHz bands included in the secondary 40 MHz band within the 80 MHz band. For example, when the third puncturing pattern is applied, puncturing can be applied only to the secondary 20 MHz band included in the primary 80 MHz band within the 160 MHz band (or 80+80 MHz band). For example, when the fourth puncturing pattern is applied, a primary 40 MHz band included in the primary 80 MHz band within the 160 MHz band (or 80+80 MHz band) may be present, and puncturing may be applied to at least one 20 MHz channel that does not belong to the primary 40 MHz band.

[0129] 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.

[0130] 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 individually configured in units of 80 MHz. For example, if the bandwidth of the PPDU is 160 MHz, the PPDU may include a first U-SIG for 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 about a 160 MHz bandwidth, and the second field of the second U-SIG may include information about preamble puncturing applied to the second 80 MHz band (i.e., information about a preamble puncturing pattern). Meanwhile, the UHR-SIG consecutive to the first U-SIG may include information about preamble puncturing applied to the second 80 MHz band (i.e., information about a preamble puncturing pattern), and the UHR-SIG consecutive to the second U-SIG may include information about preamble puncturing applied to the first 80 MHz band (i.e., information about a preamble puncturing pattern).

[0131] Additionally or alternatively, U-SIG and UHR-SIG may include information regarding preamble puncturing based on the following methods. 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).

[0132] 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 can contain different U-SIGs.

[0133] The UHR-SIG of FIG. 5 may include control information for a receiving STA. The UHR-SIG may be transmitted via at least one symbol, and each 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.

[0134] UHR-SIG provides additional signals to the U-SIG field to enable STAs to interpret / decode UHR PPDUs. The UHR-SIG field may contain U-SIG overflow bits that are common to all users. The UHR-SIG field also contains resource allocation information, allowing STAs to look up resources used in fields containing data fields / UHR-STF / UHR-LTF (i.e., UHR modulated fields of an UHR PPDU).

[0135] The frequency resources of the UHR-LTF, UHR-STF, and data fields illustrated in FIG. 5 can be determined based on RUs (resource units) defined by multiple subcarriers / tones. That is, the UHR-LTF, UHR-STF, and data fields of this specification can be transmitted / received through RUs (resource units) defined by multiple subcarriers / tones.

[0136] FIG. 6 is a diagram illustrating the layout of resource units (RUs) used for a 20 MHz PPDU. That is, the 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.

[0137] As shown at the top of Fig. 6, 26 units (i.e., units corresponding to 26 tones) can be arranged. Six tones can be used as a guard band in the leftmost band of the 20 MHz band, and five tones can be used as a guard band in the rightmost band of the 20 MHz band. In addition, seven DC tones can be inserted in the center band, i.e., the DC band, and 26 units corresponding to 13 tones can exist on each side of the DC band. In addition, 26 units, 52 units, and 106 units can be allocated to other bands. Each unit can be allocated for a receiving station, i.e., a user.

[0138] Meanwhile, the RU arrangement of FIG. 6 is utilized not only in a situation for multiple users (MUs) but also in a situation for a single user (SU), in which case it is possible to use one 242-unit as shown at the bottom of FIG. 4, in which case three DC tones can be inserted.

[0139] In the example of Fig. 6, RUs of various sizes, such as 26-RU, 52-RU, 106-RU, and 242-RU, are proposed. Since the specific sizes 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 represented as N-tone RU, etc. For example, 26-RU may be represented as 26-tone RU.

[0140] Figure 7 is a diagram showing the layout of resource units (RUs) used for 40MHz PPDU.

[0141] As in the example of Fig. 6 where RUs of various sizes were used, the example of Fig. 7 can also use 26-RU, 52-RU, 106-RU, 242-RU, 484-RU, etc. In addition, 5 DC tones can be inserted at the center frequency, 12 tones can be used as a guard band in the leftmost band of the 40 MHz band, and 11 tones can be used as a guard band in the rightmost band of the 40 MHz band.

[0142] Additionally, as illustrated, 484 RUs 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.

[0143] Figure 8 is a diagram illustrating the layout of resource units (RUs) used for an 80MHz PPDU. The layout of resource units (RUs) used in this specification may vary. For example, the layout of resource units (RUs) used in the 80MHz band may vary.

[0144] Figure 9 illustrates an operation according to UL-MU. As illustrated, a transmitting STA (e.g., AP) may perform channel access through contending (i.e., backoff operation) and transmit a trigger frame (930). That is, the transmitting STA (e.g., AP) may transmit a PPDU including a trigger frame (930). When a PPDU including a trigger frame is received, a TB (trigger-based) PPDU is transmitted after a delay of SIFS.

[0145] TB PPDUs (941, 942) are transmitted at the same time and can be transmitted from multiple STAs (e.g., User STAs) whose AIDs are indicated in the Trigger frame (930). The ACK frame (950) for the TB PPDU can be implemented in various forms.

[0146] Figure 10 shows an example of channels used / supported / defined within the 2.4 GHz band.

[0147] The 2.4 GHz band may be referred to by other names, such as the first band (band). Furthermore, 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 between 2.4 and 2.5 GHz) are used / supported / defined.

[0148] The 2.4 GHz band may include multiple 20 MHz channels. The 20 MHz 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 channel index 1 may be 2.412 GHz, the center frequency of a 20 MHz channel assigned channel index 2 may be 2.417 GHz, and the center frequency of a 20 MHz channel assigned channel index N may be (2.407 + 0.005*N) GHz. The channel indices may be referred to by various names, such as channel numbers. The specific numerical values ​​of the channel indices and center frequencies may change.

[0149] Figure 10 exemplarily illustrates four channels within the 2.4 GHz band. The illustrated first frequency region (1010) to fourth frequency region (1040) may each include one channel. For example, the first frequency region (1010) may include channel 1 (a 20 MHz channel having an index of 1). In this case, the center frequency of channel 1 may be set to 2412 MHz. The second frequency region (1020) may include channel 6. In this case, the center frequency of channel 6 may be set to 2437 MHz. The third frequency region (1030) may include channel 11. In this case, the center frequency of channel 11 may be set to 2462 MHz. The fourth frequency region (1040) may include channel 14. In this case, the center frequency of channel 14 may be set to 2484 MHz.

[0150] Figure 11 illustrates an example of channels used / supported / defined within the 5 GHz band.

[0151] The 5 GHz band may be referred to by other names, such as a second band / band, etc. The 5 GHz band may refer to a frequency range in which channels with center frequencies greater than or equal to 5 GHz 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 are subject to change.

[0152] Multiple channels within the 5 GHz band include Unlicensed National Information Infrastructure (UNII)-1, UNII-2, UNII-3, and ISM. UNII-1 may be referred to as UNII Low. UNII-2 may include frequency ranges called UNII Mid and UNII-2Extended. UNII-3 may be referred to as UNII-Upper.

[0153] Within the 5 GHz band, multiple channels can be configured, and the bandwidth of each channel can be variously configured, such as 20 MHz, 40 MHz, 80 MHz, or 160 MHz. For example, the 5170 MHz to 5330 MHz frequency domain / range within UNII-1 and UNII-2 can be divided into eight 20 MHz channels. The 5170 MHz to 5330 MHz frequency domain / range can be divided into four channels through a 40 MHz frequency domain. The 5170 MHz to 5330 MHz frequency domain / range can be divided into two channels through an 80 MHz frequency domain. Alternatively, the 5170 MHz to 5330 MHz frequency domain / range can be divided into one channel through a 160 MHz frequency domain.

[0154] Figure 12 illustrates an example of channels used / supported / defined within the 6 GHz band.

[0155] The 6 GHz band may also be referred to by other names, such as the third band / band. The 6 GHz band may refer to the frequency range in which channels with center frequencies above 5.9 GHz are used, supported, or defined. The specific figures shown in Figure 12 are subject to change.

[0156] For example, the 20 MHz channel of FIG. 12 can be defined from 5.940 GHz. Specifically, the leftmost channel among the 20 MHz channels of FIG. 12 can have an index of 1 (or channel index, channel number, etc.), and a center frequency of 5.945 GHz can be assigned. That is, the center frequency of the indexed channel N can be determined as (5.940 + 0.005*N) GHz.

[0157] Accordingly, the indexes (or channel numbers) of the 20 MHz channels of 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, It can be 197, 201, 205, 209, 213, 217, 221, 225, 229, 233. Also, according to the (5.940 + 0.005*N) GHz rule mentioned above, the indices of the 40 MHz channels in Fig. 12 can 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.

[0158] Below, the structure and types / subtypes of MAC frames are described.

[0159] Fig. 13 illustrates an example of a header of a MAC frame. As illustrated, the MAC frame may include a frame control field / information of 2 octets in length, a duration field / information of 2 octets in length, a RA (Receiver Address) field / information of 6 octets in length, and a TA (Transmitter Address) field / information of 6 octets in length. As illustrated in Fig. 13, the four fields may be consecutive to each other. 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.

[0160] The MAC header illustrated in Fig. 13 may be positioned at the very front of a MAC frame. That is, the MAC frame may include a MAC header as illustrated in Fig. 13 and MAC body fields / information subsequent to the MAC header. The MAC frame including the MAC header of Fig. 13 is inserted / included in the data field of the PPDU (e.g., UHR PPDU) illustrated in Fig. 5.

[0161] The MAC frames included in the data field of the PPDU of this specification can be classified into various types. For example, the MAC frames of this specification can be classified into control frames, management frames, and data frames.

[0162] For example, the 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 WLAN. For the management frame, the values ​​of the type fields (B3 and B2) in FIG. 13 are set to 00. In addition, 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).

[0163] For example, the control frame includes 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 WLAN. For the control frame, the value of the type field (B3 and B2) in FIG. 13 is 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).

[0164] For example, the data frame includes (QoS) Data, (QoS) Null, etc. defined in conventional WLAN. For the management frame, the value of the type field (B3 and B2) of Fig. 13 is set to 10.

[0165] The MAC frame / signal used in this specification can be identified through the type field / information and subtype field / information described above. For example, “frame” in this specification can mean a MAC frame in which the type bits B3 and B2 bits in the frame control field of the MAC header are set to 01, and the subtype bits B7, B6, B5, and B4 bits in the frame control field are set to 0010. Various MAC frames described in this specification are inserted / included in the data fields of various PPDUs (e.g., HE / VHT / HE / EHT / UHR PPDUs).

[0166] FIG. 14 illustrates a modified example of a transmitting device and / or a receiving device of the present specification.

[0167] The devices (e.g., AP STA, non-AP STA) illustrated in FIGS. 1 to 4 may be modified as illustrated in FIG. 14. The transceiver (630) of FIG. 14 may be identical to the transceivers (113, 123) of FIG. 1. The transceiver (630) of FIG. 14 may include a receiver and a transmitter.

[0168] The processor (610) of FIG. 14 may be identical to the processor (111, 121) of FIG. 1. Alternatively, the processor (610) of FIG. 14 may be identical to the processing chip (114, 124) of FIG. 1.

[0169] The memory (150) of FIG. 14 may be the same as the memory (112, 122) of FIG. 1. Alternatively, the memory (150) of FIG. 14 may be a separate external memory different from the memory (112, 122) of FIG. 1.

[0170] Referring to FIG. 14, a power management module (611) manages power to a processor (610) and / or a transceiver (630). A battery (612) supplies power to the power management module (611). A display (613) outputs results processed by the processor (610). A keypad (614) receives input to be used by the processor (610). The keypad (614) may be displayed on the display (613). A SIM card (615) may be an integrated circuit used to securely store an international mobile subscriber identity (IMSI) and an associated key used to identify and authenticate a subscriber in a mobile phone device, such as a mobile phone or computer.

[0171] Referring to FIG. 14, the speaker (640) can output sound-related results processed by the processor (610). The microphone (641) can receive sound-related input to be used by the processor (610).

[0172] 1. EHT sounding protocol

[0173] Transmit beamforming and Downlink Multi-User-Multi-Input-Multi-Output (DL MU-MIMO) require knowledge of the channel state to compute a steering matrix applied to the transmitted signal to optimize reception at one or more receivers. The EHT STA determines the channel state information using the EHT sounding protocol. The EHT sounding protocol provides an explicit feedback mechanism, defined as EHT non-trigger-based (non-TB) sounding and EHT trigger-based (TB) sounding. Here, the EHT beamformee measures the channel using training signals transmitted by the EHT beamformer (i.e., the EHT sounding NDP) and sends back a transformed estimate of the channel state. The EHT beamformer uses this estimate to derive the steering matrix.

[0174] EHT Beamformer returns an estimate of the channel state from an EHT compressed Beamforming / CQI report contained in one or more EHT Compressed Beamforming / CQI frames. There are three types of EHT compressed Beamforming / CQI reports.

[0175] - SU Feedback: EHT Compression Beamforming / CQI report consists of EHT Compression Beamforming report field.

[0176] - MU Feedback: The EHT Compressed Beamforming / CQI report consists of an EHT Compressed Beamforming report field and an EHT MU Exclusive Beamforming report field.

[0177] - CQI Feedback: EHT Compression Beamforming / CQI Reporting consists of an EHT CQI Reporting field.

[0178] Note that the use of EHT TB sounding does not necessarily imply MU feedback. EHT TB sounding is also used to obtain SU feedback and CQI feedback.

[0179] Figure 15 shows an example of EHT non-TB sounding.

[0180] The EHT non-TB sounding sequence is initiated by the EHT beamformer using an individually addressed EHT NDP Announcement frame containing exactly one STA information field, followed by an SIFS followed by the EHT sounding NDP. The EHT beamformer responds with an EHT Compressed Beamforming / CQI frame after an SIFS.

[0181] The AID11 subfield of the STA Information field shall be set to the AID of the STA identified by the RA field of the EHT NDP Announcement frame, or shall be set to 0 if the STA identified by the RA field is a mesh STA, AP, or IBSS STA.

[0182] An example of an EHT non-TB sounding sequence with a single EHT beamformer is shown in Fig. 12.

[0183] Figure 16 shows an example of EHT TB sounding.

[0184] An EHT TB sounding sequence is initiated by an EHT beamformer using a broadcast EHT NDP Announcement frame with two or more STA information fields, followed by an SIFS followed by an EHT sounding NDP, and then a SIFS followed by a Beamforming Report Poll (BFRP) trigger frame. Each EHT beamformer responds after an SIFS with an EHT TB PPDU containing one or more EHT Compressed Beamforming / CQI frames. A BFRP trigger frame transmitted within an EHT TB sounding sequence must request an EHT TB PPDU.

[0185] An example of an EHT TB sounding sequence with two or more EHT beamformers is shown in FIG. 13.

[0186] An EHT beamformer initiating an EHT TB sounding sequence must transmit an EHT NDP Announcement frame containing two or more STA information fields and the RA field set to the broadcast address.

[0187] The EHT beamformer may initiate an EHT TB sounding sequence to request SU, MU, or CQI feedback.

[0188] Figure 17 shows an example of the EHT NDP Announcement frame format.

[0189] The VHT / HE / EHT NDP Announcement frame has three variants: the VHT NDP Announcement frame, the HE NDP Announcement frame, and the EHT NDP Announcement frame. Each variant is distinguished by the configuration of the HE subfield and the Ranging subfield within the Sounding Dialog Token field.

[0190] The VHT / HE / EHT NDP Announcement frame contains at least one STA Info field. If the VHT / HE / EHT NDP Announcement frame contains only one STA Info field, the RA field is set to the address of an STA that can provide feedback. If the VHT / HE / EHT NDP Announcement frame contains more than one STA Info field, the RA field is set to the broadcast address.

[0191] The TA field is set to the address of the STA transmitting the VHT / HE / EHT NDP Announcement frame or the bandwidth signaling TA of the STA transmitting the VHT / HE / EHT NDP Announcement frame.

[0192] The Resolution subfield of the Partial BW Info subfield indicates the resolution bandwidth for each bit of the Feedback Bitmap subfield. The Feedback Bitmap subfield indicates the request for each resolution bandwidth from the lowest frequency to the highest frequency, with B1 indicating the lowest resolution bandwidth. Each bit of the Feedback Bitmap subfield is set to 1 if feedback is requested for the corresponding resolution bandwidth.

[0193] The Partial BW Info subfield is defined in the format at the bottom of Figure 14. The Resolution bit indicates the feedback resolution bandwidth. The Resolution bit is set to 0 to indicate a resolution of 20 MHz when the BW subfield is set to 0 to 3, and is set to 1 to indicate a resolution of 40 MHz when the BW subfield is set to 4. The Feedback Bitmap subfield indicates each resolution bandwidth for which the beamformer requests feedback. Each bit in the Feedback Bitmap subfield is set to 1 if feedback is requested for the corresponding bandwidth, and 0 otherwise.

[0194] If the bandwidth of the EHT NDP Announcement frame is less than 320 MHz, the Resolution bit B0 is set to 0 to indicate a resolution of 20 MHz.

[0195] - When the bandwidth of the EHT NDP Announcement frame is 20 MHz, B1 is set to 1 to indicate a feedback request for a 242-tone RU. B2-B8 are reserved and set to 0.

[0196] - When the bandwidth of the EHT NDP Announcement frame is 40 MHz, B1 and B2 indicate feedback requests for each of the two 242-tone RUs, from low to high frequency. B3-B8 are reserved and set to 0.

[0197] - When the bandwidth of the EHT NDP Announcement frame is 80 MHz, B1 to B4 represent feedback requests for each of the four 242-tone RUs, from low frequency to high frequency. B5 to B8 are reserved and set to 0. If B1 to B4 are all set to 1, it represents a feedback request for the 996-tone RU.

[0198] - When the bandwidth of the EHT NDP Announcement frame is 160 MHz, B1-B8 represent feedback requests for each of the eight 242-tone RUs from low to high frequency. If B1-B4 are all set to 1, it represents a feedback request for the lower 996-tone RU, and if B5-B8 are all set to 1, it represents a feedback request for the upper 996-tone RU.

[0199] When the bandwidth of the EHT NDP Announcement frame is 320 MHz, the Resolution bit B0 is set to 1 to indicate a resolution of 40 MHz. B1 through B8 represent feedback requests for each of the eight 484-tone RUs from low to high frequency. When B1 and B2 are both set to 1, it represents a feedback request for the lowest 996-tone RU, when B3 and B4 are both set to 1, it represents a feedback request for the second-lowest 996-tone RU, when B5 and B6 are both set to 1, it represents a feedback request for the second-highest 996-tone RU, and when B7 and B8 are both set to 1, it represents a feedback request for the highest 996-tone RU.

[0200] 1. Spatial modulation

[0201] Spatial modulation is a technology that increases transmission rate by digitizing the on / off status of antennas. It is particularly useful in situations where the number of transmit antennas exceeds the number of transmit streams, resulting in higher transmission rate gains without compromising the number of transmission streams. However, it has the disadvantage of requiring a complex receiver based on the Log-Likelihood Ratio (LLR) to detect which antennas are active.

[0202] To apply beamforming in a spatial modulation system, LTF symbols capable of estimating the channel for all possible component matrices must be included in the PPDU and transmitted to enable correct channel estimation. Here, component matrix means that if there are 4 AP TX antennas and 2 STA RX antennas and only 2 are active spatial modulations to be applied, there can be 6 2 by 2 HV matrices, which is 4C2 (=(4×3) / (2×1)=6), and 4 possible HV matrices when 2-bit spatial modulation encoding is performed. In addition, applying beamforming itself may be possible only when the compressed beamforming matrix for all component matrices (2 by 2 V matrix) is fed back. Alternatively, if all of the U matrix and gamma matrix are fed back, it may not be necessary to feed back all of the component matrices, but there are situations where the feedback overhead of the component matrices is lower depending on the antenna combination. (2 by 3, 2 by 4 channel situations, etc.) On the other hand, in UL (uplink) situations (when the dimension of the U matrix is ​​much higher than the dimension of the V matrix), feeding back all component V matrices can be more resource-efficient in terms of feedback overhead in many situations than feeding back the U matrix. However, in this situation, it can be applied only by sacrificing the transmission stream, so the spatial modulation transmission rate must be higher than the stream loss to be applied advantageously.Considering this LTF overhead or sounding feedback overhead, it may be a trend to not use beamforming, but if you want to apply it to long packets, the throughput gain may be better than the loss, and beamforming may be applied for this purpose.

[0203] However, this issue has not been addressed in the current standard because a single user does not need to estimate multiple channel matrices. In this situation, when performing channel sounding, only the beamforming V matrix in the case where all transmit antennas are used was fed back, but in order to apply beamforming in spatial modulation, feedback for multiple component V matrices is required. (Feedback of the U matrix and gamma matrix is ​​not covered in this specification.) Therefore, this specification proposes a method for feeding back multiple component V matrices and the signaling required for that.

[0204] Figure 18 illustrates an example block diagram of a TX device implementing spatial modulation.

[0205] Referring to Fig. 18, Spatial Modulation (SM) can be implemented by introducing a Spatial-Antenna Stream (SAS) into a wireless LAN system. On the TX side, a spatial stream (SS) is mapped to a spatial antenna stream, and the spatial antenna stream is mapped to a TX antenna.

[0206] At this time, the spatial streams (SS) are sorted by transmission priority and are less than or equal to the number of RXs. The spatial streams are mapped to spatial antenna streams (SAS) through the introduced SM. The SAS can be mapped to TX antennas using a proprietary solution, and the number of TX antennas is greater than or equal to the SAS.

[0207] CSD (Cyclic Shift Diversity) can be applied to SS.

[0208] The number of LTFs follows the number of available SAS, not the SS. LTF expansion can be applied according to the P-matrix expansion (e.g., for 4 SAS cases, a 4X4 or 4X8 P-matrix can be applied).

[0209] The linear operating range of the TX power amplifier must be flexible enough to support cases where the maximum TX power is split across the streams between SS and SAS.

[0210] The beamforming of the existing standard can be performed based on a non-TB (non-trigger-based) sounding protocol as shown in FIG. 15. This is an example, and TB (trigger-based) sounding as shown in FIG. 16 can also be used. Specifically, when the beamformer transmits an NDPA (Null data PPDU announcement) to convey feedback-related instruction information and then transmits an NDP (Null Data PPDU) after a SIFS, the beamformer estimates the channel using the NDP and then transmits the estimated channel information through a compressed beamforming / CQI frame. The beamformer can transmit a PPDU with beamforming applied based on the received channel information to the beamformer.

[0211] However, if the sounding feedback mechanism of the existing standard is used as is, only the beamforming matrix when all antennas are active is fed back, so the beamformer cannot obtain the beamforming matrix when spatial modulation is applied.

[0212] Therefore, the purpose of this specification is to propose a sounding feedback mechanism that enables STAs seeking to apply spatial modulation to obtain an appropriate beamforming matrix. To this end, we propose modifying the NDPA frame and the compressed beamforming / CQI frame, as shown in Figure 19.

[0213] Figure 19 illustrates an example of the sounding feedback mechanism proposed in this specification.

[0214] The scope disclosed in this specification is not limited by the name NDPA (or modified NDPA) frame and / or compressed beamforming / CQI (or modified compressed beamforming / CQI) frame. That is, the scope disclosed in this specification may include frames of any name that include characteristic fields / information of the NDPA frame / compressed beamforming / CQI frame described below. For example, NDPA may be referred to as a spatial modulation information request frame, and compressed beamforming / CQI may be referred to as a spatial modulation information report frame.

[0215] In this specification, a beamformer is not limited to an AP and can be applied even when a non-AP STA is a beamformer. Furthermore, in this specification, a beamformee is not limited to a non-AP STA and can be applied even when an AP is a beamformee. For example, although the examples in this specification primarily describe downlink beamforming for downlink transmissions from an AP to a non-AP STA for ease of understanding, this specification also includes the application of the examples described below to uplink beamforming for uplink transmissions from a non-AP STA to an AP.

[0216] 2. Proposed sounding feedback mechanism

[0217] 1) NDPA-based spatial modulation sounding & feedback request

[0218] The beamformer must transmit the NDPA to indicate that the sounding & feedback sequence is intended for spatial modulation. It must also convey the information the beamformer needs to generate feedback information. For this purpose, the following fields are proposed for inclusion in the NDPA:

[0219] A. Spatial modulation indication

[0220] This field requests the beamformer to provide feedback on the beamforming matrix for spatial modulation. It can utilize 1 bit. For example, a spatial modulation indication of 1 can indicate that spatial modulation has been applied, while a spatial modulation indication of 0 can indicate that it has not been applied.

[0221] B. Spatial modulation order

[0222] This field indicates the modulation order of spatial modulation. It conveys how many bits the spatial modulation applied to one subcarrier consists of. Up to 3 bits can be utilized. (When using 4 elements in 8 antennas, up to 7 bits can be configured, and since the minimum bit that can express 7 is 3) For example, the field can be configured as shown in Table 1. In some cases, this field may not be necessary when the system is designed so that the modulation order is determined naturally once the number of TX antennas and the number of active antennas are determined to reduce complexity. However, this may be undesirable because it may not be possible to select an appropriate transmission rate depending on the SNR situation. Table 1 shows an example of the spatial modulation order field configuration.

[0223] Field valuesModulation order011223344556677reserved

[0224] C. # of active antenna elements

[0225] This field indicates the number of active antenna elements. This field is transmitted to specify the beamforming matrix dimension of the beamformer. Two bits can be used to indicate 1 to 4. Table 2 shows an example of the configuration of the # of active antenna elements field.

[0226] Field values# of active antenna elements01122334

[0227] The above fields may exist in the STA Info field of NDPA as shown in Fig. 20.

[0228] Figure 20 illustrates an example of the STA Info field of NDPA proposed in this specification.

[0229] Alternatively, if you want to request multiple spatial modulation information at once, it can be structured as follows. For example, if you want to operate a system that can apply different modulation orders depending on the SNR (Signal Noise Ratio) or channel quality, you may need signaling fields for multiple spatial modulation orders and active antenna numbers. In other words, the two fields mentioned above can be designed to exist multiple times within a single STA Info field.

[0230] D. Spatial modulation indication

[0231] A. Set the same as the spatial modulation indication. That is, this is a field that requests the beamformer to feed back the beamforming matrix for spatial modulation. 1 bit can be utilized. For example, when the spatial modulation indication is 1, it can indicate that spatial modulation has been applied, and when the spatial modulation indication is 0, it can indicate that it has not been applied.

[0232] E. # of spatial modulation modes

[0233] This field indicates the number of spatial modulation order fields and # of active antenna elements.

[0234] F. Spatial modulation order

[0235] B. Set the same as Spatial modulation order, but can exist multiple times depending on the field value of # of spatial modulation modes.

[0236] G. # of active antenna elements

[0237] C. Same as # of active antenna elements, but can exist multiple times depending on the field value of # of spatial modulation modes.

[0238] The above fields can exist in the STA Info field of NDPA as shown in Fig. 21. However, since the STA Info field has only 4 reserved bits, the STA Info field needs to be expanded to apply the proposed technology.

[0239] Figure 21 illustrates another example of the STA Info field of NDPA proposed in this specification.

[0240] 2) Compressed beamforming / CQI frame-based spatial modulation beamforming matrix feedback

[0241] Let's assume the # of active antenna elements is N. Also, let's assume the spatial modulation order is M. The above values ​​can be the result of interpreting the NDPA field, or they can be values ​​independently selected by the beamformer. This is because the beamformer can provide feedback as instructed, but the beamformer can also provide feedback of its own judgment due to reasons such as inability to handle decoding complexity capability. This decision can be indicated in the MIMO control field.

[0242] At this time, since it is desirable to configure candidates as powers of 2 for symbol encoding, the number of beamforming matrices that the beamformer must feed back is 2^M, and the dimension of the corresponding matrix is ​​N by Nr. Here, Nr is the number of receiving antennas.

[0243] Based on this, we propose to configure the fields of the Compressed beamforming / CQI frame as follows.

[0244] A. MIMO Control

[0245] i. Spatial modulation indication

[0246] This field informs the beamformer to feed back the beamforming matrix for spatial modulation. 1 bit can be used.

[0247] ii. Spatial modulation order

[0248] This field indicates the modulation order of spatial modulation. It conveys the number of bits of spatial modulation applied to a single subcarrier. Up to 3 bits can be utilized (up to 6-bit modulation is possible when using 4 elements in 8 antennas, and the minimum bit that can express 6 is 3).

[0249] iii. # of active antenna elements

[0250] This field indicates the number of active antenna elements. This field is transmitted to specify the beamforming matrix dimension of the beamformer. Two bits can be used to indicate 1 to 4.

[0251] The above fields can exist in the MIMO Control field as shown in Fig. 22. Since the MIMO control field has only 6 reserved bits, the MIMO Control field needs to be expanded to apply the proposed method.

[0252] Figure 22 illustrates an example of the MIMO control field proposed in this specification.

[0253] B. Spatial modulation based compressed beamforming report

[0254] This field transmits phi and psi information by rotating 2^M N by Nr beamforming matrices. The order of the beamforming matrices can be determined in advance through a pre-arrangement. In other words, the order of the beamforming matrices for a given antenna combination can be determined in advance through a pre-arrangement, thereby avoiding unnecessary signaling.

[0255] The above field may exist in a Spatial modulation based compressed beamforming report field as shown in Fig. 23.

[0256] Figure 23 illustrates an example of a spatial modulation based compressed beamforming report proposed in this specification.

[0257] Alternatively, if you want to transmit multiple spatial modulation information at once, it can be structured as follows. In this case, if there are multiple spatial modulation orders, define each as M_i (i=1,2,..,K).

[0258] C. MIMO Control (if you want to request multiple spatial modulation information at once)

[0259] iv. Spatial modulation indication

[0260] This field informs the beamformer to feed back the beamforming matrix for spatial modulation. 1 bit can be used.

[0261] v. # of spatial modulation modes

[0262] This field indicates the number of spatial modulation order fields and # of active antenna elements.

[0263] vi. Spatial modulation order

[0264] ii. It is set to the same as partial modulation order, but can exist multiple times depending on the value of the #of spatial modulation modes field.

[0265] vii. # of active antenna elements

[0266] iii. It is set identically to # of active antenna elements, but can exist multiple times depending on the value of the #of spatial modulation modes field.

[0267] The above fields may exist in the MIMO Control field as shown in Fig. 24.

[0268] Figure 24 illustrates another example of the MIMO control field proposed in this specification.

[0269] D. Spatial modulation based compressed beamforming report (if you want to request multiple spatial modulation information at once)

[0270] It is a field that transmits phi and psi information by rotating the given N by Nr beamforming matrices, which are the sum of the numbers from i=1 to K for 2^(M_i). The order of the beamforming matrices can be determined in advance through an agreement.

[0271] The above field may exist in a Spatial modulation based compressed beamforming report field as shown in FIG. 25.

[0272] Figure 25 illustrates another example of a spatial modulation based compressed beamforming report proposed in this specification.

[0273] 3. Device / method in which an example of this specification operates

[0274] 2.1. How the signals of this specification are transmitted / received

[0275] Figure 26 illustrates an example of a PPDU of this specification.

[0276] Fig. 26 is an example of a PPDU that can be used in a UHR system, and all or part of all parts (i.e., fields) illustrated can be divided into multiple subparts / subfields. Except for the LTF and Data fields, the remaining fields can be transmitted in units of 4us * N (N is an integer). The LTF and Data fields may not be in units of 4us depending on the GI length combination. A common subcarrier frequency spacing value (delta_f = 312.5 kHz / N or 312.5 kHz * N, N = integer) may be applied to all of the illustrated fields, or the first delta_f may be applied to the first part (e.g., all Legacy-Part, all / part of SIG-Part), and the second delta_f (e.g., a value smaller than the first delta_f) may be applied to all / part of the remaining parts.

[0277] The illustrated Legacy Part (100) may include at least one of a conventional Non-HT Short Training Field (L-STF), a Non-HT Long Training Field (L-LTF), and a Non-HT Signal Field (L-SIG).

[0278] The illustrated SIG-Part (200) may include various control information for the transmitted PPDU. For example, it may include control information for decoding the STF-Part (300), LTF-Part (400), and Data (500).

[0279] The illustrated STF-Part (300) may include an STF sequence.

[0280] The illustrated LTF-Part (400) may include a training field (i.e., an LTF sequence) for channel estimation.

[0281] The data field (500) includes user data and may include a packet for an upper layer. That is, it may include an MPDU (MAC Frame).

[0282] An NDPA frame including new fields according to the present specification (e.g., Spatial modulation indication, # of spatial modulation modes, spatial modulation order, # of antenna elements) may be included in the data field (500) of the first PPDU.

[0283] A UHR Compressed Beamforming / CQI frame including new fields according to the present specification (e.g., Spatial modulation indication, spatial modulation order, # of active antenna elements, spatial modulation based compressed beamforming report) may be included in the data field (500) of the second PPDU.

[0284] Beamforming can be applied to NDP's LTF symbols.

[0285] Additionally, since Fig. 26 is a predicted drawing, some of the fields shown may be omitted and the order of the fields may be changed in various ways.

[0286] 2.2. Method of this specification

[0287] 1) Transmission method

[0288] Figure 27 illustrates a procedure for a transmitting device according to the present embodiment to perform a sounding protocol for applying spatial modulation.

[0289] An example of FIG. 27 can be performed at a transmitting device (AP and / or non-AP STA).

[0290] Some of the steps (or detailed sub-steps described below) in the example of Fig. 27 may be omitted or changed.

[0291] S100: A transmitting device (transmitting STA or beamformer) may generate an MPDU containing an NDPA frame including one or more of the following fields: spatial modulation indication, # of spatial modulation modes, spatial modulation order, and / or # of active antenna elements.

[0292] The transmitting device can configure / generate a PPDU based on the generated MPDU. The step of configuring / generating the PPDU can include a step of configuring / generating each field of the PPDU. That is, step S300 includes a step of configuring U-SIG and UHR SIG fields. In addition, step S300 can include a step of generating an STF / LTF sequence. The STF / LTF sequence can be generated based on a preset STF generation sequence / LTF generation sequence.

[0293] A transmitting device can transmit a configured PPDU to a receiving device.

[0294] In PPDU transmission, the transmitting device may perform at least one of operations such as beamforming, CSD, Spatial Mapping, IDFT / IFFT operation, and GI insertion.

[0295] For example, beamforming can be performed based on the V matrix most recently received from the receiving device (or beamformer). At this time, an appropriate one of the fed-back V matrices can be selected and performed.

[0296] A signal / field / sequence configured according to this specification can be transmitted in the form of FIG. 26.

[0297] S200: The transmitting device may transmit one or more NDPs to the receiving device after a predetermined time (e.g., SIFS) after transmitting the NDPA.

[0298] S300: The transmitting device can receive a compressed beamforming / CQI frame from the receiving device.

[0299] For example, the transmitting device may receive all or part of the PPDU. The received signal may have the form of FIG. 26. For example, the transmitting device may perform an operation to restore the results of the applied CSD, Spatial Mapping, IDFT / IFFT operation, and GI insertion operation on the received PPDU.

[0300] For example, a transmitting device can decode the L-SIG, U-SIG, and UHR-SIG of a PPDU based on Legacy STF / LTF, and obtain information contained in the L-SIG, U-SIG, and UHR-SIG fields. Based on that information, the transmitting device can decode the remaining portion of the PPDU.

[0301] For example, a transmitting device may perform a processing operation to forward decoded data to a higher layer (e.g., a MAC layer). Furthermore, if the higher layer instructs the PHY layer to generate a signal in response to the data forwarded to the higher layer, a subsequent operation may be performed.

[0302] For example, the transmitting device can decode / parse the acquired MPDU.

[0303] For example, a transmitting device can decode a PPDU from a receiving device to obtain an MPDU containing compressed beamforming / CQI. By decoding / parsing the MPDU, etc., the information can be obtained through fields included in the compressed beamforming / CQI frame (e.g., Spatial modulation indication, # of spatial modulation modes, spatial modulation order, # of active antenna elements, and / or spatial modulation based compressed beamforming report).

[0304] A compressed beamforming / CQI frame may be transmitted by a receiving device upon a request / trigger from a transmitting device. Alternatively, the compressed beamforming / CQI frame may be transmitted by a receiving device without a request / trigger from the transmitting device.

[0305] A transmitting device can apply spatial modulation to subsequent data transmissions to a corresponding receiving device based on information obtained from fields included in a compressed beamforming / CQI frame. For example, a transmitting device can receive a compressed beamforming / CQI frame and store in memory the V matrices required for spatial modulation for use in the next PPDU transmission.

[0306] S400: The transmitter can perform the optimization of the present disclosure based on compressed beamforming / CQI. That is, it can obtain a diagonal phase rotation matrix to be multiplied by the beamforming matrix.

[0307] S500: The transmitting device can apply optimized parameters for subsequent beamforming transmissions to the receiving device based on information obtained from fields included in the compressed beamforming / CQI frame. For example, the transmitting device can receive the compressed beamforming / CQI frame, generate a beamforming vector to be used for the next PPDU transmission, and store it in memory.

[0308] 2) Receiving method

[0309] Figure 28 illustrates a procedure for a receiving device according to the present embodiment to perform a sounding protocol for applying spatial modulation.

[0310] The above-described PPDU can be received according to an example of FIG. 28.

[0311] An example of FIG. 28 can be performed at a receiving device (AP and / or non-AP STA).

[0312] Some of the steps (or detailed sub-steps described below) in the example of Fig. 28 may be omitted.

[0313] S400: For example, the receiving device may receive all or part of the PPDU. The received signal may be in the form of FIG. 26. For example, the receiving device may perform an operation to restore the results of the applied CSD, Spatial Mapping, IDFT / IFFT operation, and GI insertion operation on the received PPDU.

[0314] For example, a receiving device can decode the L-SIG, U-SIG, and UHR-SIG of a PPDU based on Legacy STF / LTF, and obtain information contained in the L-SIG, U-SIG, and UHR-SIG fields. Based on that information, the receiving device can decode the remaining portion of the PPDU.

[0315] For example, a receiving device may perform a processing operation to pass decoded data to a higher layer (e.g., a MAC layer). Furthermore, if the higher layer instructs the PHY layer to generate a signal in response to the data passed to the higher layer, a subsequent operation may be performed.

[0316] For example, the receiving device can decode / parse the acquired MPDU.

[0317] A receiving device (receiving STA or beamformer) according to the present disclosure can obtain information about a spatial modulation indication, # of spatial modulation modes, spatial modulation order, and / or # of active antenna elements included in an NDPA frame through PPDU decoding or the like.

[0318] S500: The receiving device may perform channel estimation after receiving an NDPA frame and subsequently receiving one or more NDPs.

[0319] S600: The receiving device can determine parameters for optimization based on the channel estimation results. Based on the determined optimization parameters, the receiving device can generate an MPDU including a compressed beamforming / CQI frame including new fields according to the present disclosure (e.g., a Spatial modulation indication, a # of spatial modulation modes, a Spatial modulation order, a # of active antenna elements, and / or a spatial modulation based compressed beamforming report field).

[0320] A receiving device can configure / generate a PPDU based on the generated MPDU. The step of configuring / generating the PPDU may include a step of configuring / generating each field of the PPDU. For example, the PPDU configuration / generation may include a step of configuring U-SIG and UHR SIG fields, a step of generating an STF / LTF sequence, etc. The STF / LTF sequence may be generated based on a preset STF generation sequence / LTF generation sequence.

[0321] The receiving device can transmit the configured PPDU to the receiving device.

[0322] In PPDU transmission, the receiving device can perform at least one of operations such as beamforming, CSD, Spatial Mapping, IDFT / IFFT operation, and GI insertion.

[0323] A signal / field / sequence configured according to this specification can be transmitted in the form of FIG. 26.

[0324] A compressed beamforming / CQI frame may be transmitted by a receiving device upon a request / trigger from a transmitting device. Alternatively, the compressed beamforming / CQI frame may be transmitted by a receiving device without a request / trigger from the transmitting device.

[0325] The receiving device may expect subsequent beamforming transmissions from the transmitting device to be performed based on information indicated by fields included in the compressed beamforming / CQI frame.

[0326] 3.3. Device of this specification

[0327] 1) Transmitter

[0328] The transmitting device may include a memory (1920), a processor (1910), and a transceiver (1930).

[0329] The above processor (1910) can perform all / part of the operations illustrated in FIG. 27.

[0330] The illustrated transceiver (1930) includes an antenna and can perform analog signal processing. Specifically, the processor (1910) can control the transceiver (1930) to transmit a PPDU generated by the processor (1910).

[0331] Alternatively, the processor (1910) may generate a transmission PPDU and store information about the transmission PPDU in the memory (1920).

[0332] The processor (1910) may generate a first PPDU including an NDPA including one or more of a spatial modulation indication, a # of spatial modulation modes, a spatial modulation order, and / or a # of active antenna elements field and transmit the first PPDU via the transceiver (1930).

[0333] Additionally, the processor (1910) can transmit NDP through the transceiver (1930).

[0334] Additionally, the processor (1910) can transmit a PPDU to which spatial modulation is applied through a transceiver (1930).

[0335] 2) Receiving device

[0336] The receiving device may include a memory (2020), a processor (2010), and a transceiver (2030).

[0337] The transceiver (2030) can receive a PPDU based on the control of the processor (2010). For example, the transceiver (2030) may include multiple sub-units. For example, the transceiver (2030) may include at least one receiving antenna and a filter for the receiving antenna.

[0338] A PPDU received via a transceiver (2030) may be stored in a memory (2020). A processor (2010) may decode the received PPDU via the memory (2020). The processor (2010) may obtain control information (e.g., EHT-SIG) regarding Tone-Plan / RU included in the PPDU and store the obtained control information in the memory (2020).

[0339] The processor (2010) can perform decoding on the received PPDU. Specifically, it can perform operations to restore the results of CSD, Spatial Mapping, IDFT / IFFT operations, and GI insertion applied to the PPDU. The operations to restore the results of CSD, Spatial Mapping, IDFT / IFFT operations, and GI insertion can be performed by multiple processing units (not shown) individually implemented within the processor (2010).

[0340] Additionally, the processor (2010) can decode the data field of the PPDU received through the transceiver (2030).

[0341] Additionally, the processor (2010) may process the decoded data. For example, the processor (2010) may perform a processing operation to transmit information regarding the decoded data field to a higher layer (e.g., a MAC layer). Additionally, if the upper layer instructs the PHY layer to generate a signal in response to the data transmitted to the upper layer, a subsequent operation may be performed.

[0342] The processor (2010) may receive and decode a first PPDU including an NDPA including one or more of a spatial modulation indication, # of spatial modulation modes, a spatial modulation order, and / or # of active antenna elements through a transceiver (2030) and store the first PPDU in the memory (2020).

[0343] The receiving device can receive NDP, obtain channel information, and store it in memory (2020).

[0344] The transceiver (2030) may transmit a second PPDU including a UHR compressed beamforming / CQI frame including one or more of a Spatial modulation indication, # of spatial modulation modes, spatial modulation order, # of active antenna elements, and / or a spatial modulation based compressed beamforming report field.

[0345] 3.4. Operational Examples of This Specification

[0346] Figure 29 illustrates the overall procedure of a sounding protocol for applying spatial modulation according to the present embodiment.

[0347] NDPA frame generation (2900) refers to the process of generating an NDPA frame. Field values ​​may vary depending on the circumstances described below (either as directed by the beamformer or autonomously by the beamformee).

[0348] NDPA transmission (2910) refers to the process of transmitting the NDPA frame generated in (2900) through the first PPDU.

[0349] NDP transmission (2920) means transmitting a Null data PPDU to enable Beamformee to estimate the channel.

[0350] Channel estimation (2930) refers to the process of estimating the channel matrix from the NDP received by Beamformee.

[0351] Compressed Beamforming / CQI frame generation (2940) means generating a frame containing information necessary to create a beamformed spatial modulation signal (e.g., spatial modulation indication, # of spatial modulation modes, spatial modulation order, # of active antenna elements, and / or spatial modulation based compressed beamforming report field).

[0352] Compressed Beamforming / CQI frame transmission (2950) means transmitting the Compressed Beamforming / CQI frame generated in (2940) through PPDU.

[0353] Spatial modulation (2960) refers to the process of generating a PPDU with spatial modulation applied based on information obtained from a Compressed Beamforming / CQI frame (e.g., spatial modulation indication, # of spatial modulation modes, spatial modulation order, # of active antenna elements, and / or spatial modulation based compressed beamforming report field).

[0354] Data Transmission (2970) means transmitting the data PPDU generated in (2960).

[0355] Figure 30 is a flowchart illustrating the operation of a transmitting device according to the present embodiment.

[0356] An example of FIG. 30 may be performed at a transmitting STA or transmitting device (AP and / or non-AP STA).

[0357] Some of the steps (or detailed sub-steps described below) in the example of Figure 30 may be omitted or changed.

[0358] Through step S3010, the transmitting device (transmitting STA) can obtain information regarding the aforementioned 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.

[0359] Through step S3020, the transmitting device can configure / generate a PPDU based on the acquired control information. The step of configuring / generating the PPDU may include a step of configuring / generating each field of the PPDU. That is, step S3020 may include a step of configuring an EHT-SIG field including control information regarding a Tone Plan. That is, step S3020 may include a step of configuring a field including control information indicating the size / position of an RU (e.g., an N bitmap) and / or a step of configuring a field including an identifier (e.g., an AID) of an STA receiving the RU.

[0360] Additionally, step S3020 may include a step of generating an STF / LTF sequence to be transmitted through a specific RU. The STF / LTF sequence may be generated based on a preset STF generation sequence / LTF generation sequence.

[0361] Additionally, step S3020 may include a step of generating a data field (i.e., MPDU) to be transmitted via a specific RU.

[0362] The transmitting device can transmit the PPDU configured through step S3020 to the receiving device based on step S2630.

[0363] While performing step S3030, the transmitting device may perform at least one of operations such as CSD, Spatial Mapping, IDFT / IFFT operation, and GI insertion.

[0364] A signal / field / sequence configured according to this specification can be transmitted in the form of FIG. 5.

[0365] Figure 31 is a flowchart illustrating the operation of a receiving device according to the present embodiment.

[0366] The above-described PPDU can be received according to an example of FIG. 31.

[0367] An example of FIG. 31 may be performed at a receiving STA or receiving device (AP and / or non-AP STA).

[0368] Some of the steps (or detailed sub-steps described below) in the example of Fig. 31 may be omitted.

[0369] A receiving device (receiving STA) may receive all or part of a PPDU through step S3110. The received signal may have the form of FIG. 5.

[0370] The sub-step of step S3110 can be determined based on step S3030 of Fig. 30. That is, step S3110 can perform an operation to restore the results of the CSD, Spatial Mapping, IDFT / IFFT operations, and GI insert operations applied in step S3030.

[0371] At step S3120, the receiving device can decode 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.

[0372] More specifically, the receiving device can decode the L-SIG and EHT-SIG of the PPDU based on the Legacy STF / LTF and obtain information included in the L-SIG and EHT SIG fields. Information regarding various Tone Plans (i.e., RUs) described herein can be included in the EHT-SIG, and the receiving STA can obtain information regarding the Tone Plan (i.e., RU) through the EHT-SIG.

[0373] In step S3130, the receiving device can decode the remaining portion of the PPDU based on the information about the Tone Plan (i.e., RU) acquired in step S3120. For example, the receiving STA can decode the STF / LTF field of the PPDU based on the information about one Plan (i.e., RU). In addition, the receiving STA can decode the data field of the PPDU based on the information about the Tone Plan (i.e., RU) and acquire the MPDU included in the data field.

[0374] Additionally, the receiving device may perform a processing operation to transmit the decoded data to a higher layer (e.g., MAC layer) through step S3130. Furthermore, if the generation of a signal from the higher layer to the PHY layer is instructed in response to the data transmitted to the higher layer, a subsequent operation may be performed.

[0375] Hereinafter, the above-described embodiment will be described with reference to FIGS. 1 to 31.

[0376] FIG. 32 is a flowchart illustrating a procedure for performing a sounding protocol for applying beamforming when a transmitting STA according to the present embodiment applies spatial modulation.

[0377] An example of FIG. 32 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 on the 802.11be system and can satisfy backward compatibility with the 802.11be system.

[0378] An example of FIG. 32 is performed at a transmitting STA, which may correspond to a beamformer or an access point (AP). The receiving STA of FIG. 32 may correspond to a beamformee or at least one STA (station).

[0379] This embodiment proposes a method for performing beamforming by applying spatial modulation, a technique for increasing transmission rate by informing whether a specific antenna is on or off. In particular, this specification proposes a signaling method for feeding back all component V matrices.

[0380] In step S3210, the transmitting STA (station) transmits an NDPA (Null Data Packet Announcement) frame to the receiving STA.

[0381] In step S3220, the transmitting STA transmits an NDP frame to the receiving STA.

[0382] In step S3230, the transmitting STA receives a feedback frame from the receiving STA.

[0383] The above NDPA frame includes first to third fields.

[0384] The first field includes information on whether beamforming for spatial modulation is indicated. For example, if the first field is set to 1, it may indicate that spatial modulation is applied. If the first field is set to 0, it may indicate that spatial modulation is not applied.

[0385] The second field includes information about the modulation order of the spatial modulation. The modulation order of the spatial modulation may be determined based on the number of transmission antennas of the transmitting STA and the number of activated antenna elements described below. The spatial modulation may be a technology that secures a transmission stream through activated antenna elements by information about whether the transmission antennas are on or off, thereby increasing the transmission rate.

[0386] The third field includes information about the number of activated antenna elements for spatial modulation. Based on the third field, the dimension of the beamforming matrix fed back by the beamformer can be specified.

[0387] If information about the above spatial modulation is requested multiple times at once, the NDPA frame may further include a fourth field.

[0388] The fourth field may include information about the number of the second and third fields. At least one of the second and third fields may be present in one STA information field of the NDPA frame based on the fourth field.

[0389] For example, if the transmitting STA wants to request information about the spatial modulation twice at a time, the fourth field may indicate that the number of the second and third fields is two each, and one STA information field of the NDPA frame may include two second fields and two third fields.

[0390] The above feedback frame may include the first to fourth fields and the fifth field.

[0391] The first to fourth fields included in the above feedback frame may be included in a MIMO (Multi Input Multi Output) control field.

[0392] The fifth field may include quantized information about the beamforming matrix for the spatial modulation. Specifically, the fifth field may include phi and psi information for rotating the beamforming matrix.

[0393] When the number of the activated antenna elements is N and the modulation order of the spatial modulation is M, the number of the beamforming matrices is 2^M, the dimension of the beamforming matrix is ​​N x Nr, and Nr may be the number of receiving antennas of the receiving STA.

[0394] The fifth field may include a compressed beamforming report field for each of the beamforming matrices. That is, the fifth field may be configured to feed back all component V matrices of the beamforming matrix.

[0395] That is, the present embodiment proposes a sounding feedback mechanism that enables a beamformer / beamformee that wishes to apply the spatial modulation to obtain an appropriate beamforming matrix. To this end, a signaling method for feeding back all element V matrices is proposed by modifying the NDPA frame and the feedback frame (or compressed beamforming / CQI (Channel Quality Indicator) frame) in the existing sounding feedback mechanism. This has the effect of improving the overall system throughput by obtaining beamforming gain even when operating the spatial modulation.

[0396] The above feedback frame can be configured based on the above NDPA frame and the above NDP frame.

[0397] Additionally, the receiving STA receives beamformed data from the transmitting STA. The beamformed data may be generated by applying the spatial modulation based on the feedback frame.

[0398] If the receiving STA is one STA, a non-TB (Trigger Based) sounding method is used, such as steps S3210 to S3230. However, if the receiving STA is a plurality of STAs (i.e., in the case of MU feedback), a TB sounding method that triggers the feedback frame using a BFRP (Beamforming Report Poll) trigger frame may be used between steps S3220 and S3230. Specifically, the transmitting STA can transmit the BFRP trigger frame after transmitting the NDP frame, and receive the feedback frame triggered by the BFRP trigger frame. The BFRP trigger frame includes at least one user information field, and only a receiving STA identified by the user information field can transmit the feedback frame.

[0399] The above NDP frame and the above feedback frame may be transmitted in the same band as the NDPA frame. The NDP frame may be defined as a variant of the UHR MU (Multi User) PPDU.

[0400] FIG. 33 is a flowchart illustrating a procedure for performing a sounding protocol for applying beamforming when a receiving STA according to the present embodiment applies spatial modulation.

[0401] An example of FIG. 33 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 on the 802.11be system and can satisfy backward compatibility with the 802.11be system.

[0402] An example of FIG. 33 is performed at a receiving STA, which may correspond to a beamformee or at least one STA (station). The transmitting STA of FIG. 33 may correspond to a beamformer or an AP (access point).

[0403] This embodiment proposes a method for performing beamforming by applying spatial modulation, a technique for increasing transmission rate by informing whether a specific antenna is on or off. In particular, this specification proposes a signaling method for feeding back all component V matrices.

[0404] In step S3310, the receiving STA (station) receives an NDPA (Null Data Packet Announcement) frame from the transmitting STA.

[0405] In step S3320, the receiving STA receives an NDP frame from the transmitting STA.

[0406] In step S3330, the receiving STA transmits a feedback frame to the transmitting STA.

[0407] The above NDPA frame includes first to third fields.

[0408] The first field includes information on whether beamforming for spatial modulation is indicated. For example, if the first field is set to 1, it may indicate that spatial modulation is applied. If the first field is set to 0, it may indicate that spatial modulation is not applied.

[0409] The second field includes information about the modulation order of the spatial modulation. The modulation order of the spatial modulation may be determined based on the number of transmission antennas of the transmitting STA and the number of activated antenna elements described below. The spatial modulation may be a technology that secures a transmission stream through activated antenna elements by information about whether the transmission antennas are on or off, thereby increasing the transmission rate.

[0410] The third field includes information about the number of activated antenna elements for spatial modulation. Based on the third field, the dimension of the beamforming matrix fed back by the beamformer can be specified.

[0411] If information about the above spatial modulation is requested multiple times at once, the NDPA frame may further include a fourth field.

[0412] The fourth field may include information about the number of the second and third fields. At least one of the second and third fields may be present in one STA information field of the NDPA frame based on the fourth field.

[0413] For example, if the transmitting STA wants to request information about the spatial modulation twice at a time, the fourth field may indicate that the number of the second and third fields is two each, and one STA information field of the NDPA frame may include two second fields and two third fields.

[0414] The above feedback frame may include the first to fourth fields and the fifth field.

[0415] The first to fourth fields included in the above feedback frame may be included in a MIMO (Multi Input Multi Output) control field.

[0416] The fifth field may include quantized information about the beamforming matrix for the spatial modulation. Specifically, the fifth field may include phi and psi information for rotating the beamforming matrix.

[0417] When the number of the activated antenna elements is N and the modulation order of the spatial modulation is M, the number of the beamforming matrices is 2^M, the dimension of the beamforming matrix is ​​N x Nr, and Nr may be the number of receiving antennas of the receiving STA.

[0418] The fifth field may include a compressed beamforming report field for each of the beamforming matrices. That is, the fifth field may be configured to feed back all component V matrices of the beamforming matrix.

[0419] That is, the present embodiment proposes a sounding feedback mechanism that enables a beamformer / beamformee that wishes to apply the spatial modulation to obtain an appropriate beamforming matrix. To this end, a signaling method for feeding back all element V matrices is proposed by modifying the NDPA frame and the feedback frame (or compressed beamforming / CQI (Channel Quality Indicator) frame) in the existing sounding feedback mechanism. This has the effect of improving the overall system throughput by obtaining beamforming gain even when operating the spatial modulation.

[0420] The above feedback frame can be configured based on the above NDPA frame and the above NDP frame.

[0421] Additionally, the receiving STA receives beamformed data from the transmitting STA. The beamformed data may be generated by applying the spatial modulation based on the feedback frame.

[0422] If the receiving STA is one STA, a non-TB (Trigger Based) sounding method is used, such as steps S3310 to S3330. However, if the receiving STA is a plurality of STAs (i.e., in the case of MU feedback), a TB sounding method that triggers the feedback frame using a BFRP (Beamforming Report Poll) trigger frame may be used between steps S3320 and S3330. Specifically, the transmitting STA can transmit the BFRP trigger frame after transmitting the NDP frame, and receive the feedback frame triggered by the BFRP trigger frame. The BFRP trigger frame includes at least one user information field, and only a receiving STA identified by the user information field can transmit the feedback frame.

[0423] The above NDP frame and the above feedback frame may be transmitted in the same band as the NDPA frame. The NDP frame may be defined as a variant of the UHR MU (Multi User) PPDU.

[0424] <Device Configuration>

[0425] The technical features of the present specification described above can be applied to various devices and methods. For example, the technical features of the present specification described above can be performed / supported by the devices of FIG. 1 and / or FIG. 14. For example, the technical features of the present specification described above can be applied only to a part of FIG. 1 and / or FIG. 14. For example, the technical features of the present specification described above can be implemented based on the processing chip (114, 124) of FIG. 1, or based on the processor (111, 121) and the memory (112, 122) of FIG. 1, or based on the processor (610) and the memory (620) of FIG. 14. For example, the device of the present specification receives an NDPA (Null Data Packet Announcement) frame from a transmitting STA (station); receives an NDP frame from the transmitting STA; and transmits a feedback frame to the transmitting STA.

[0426] The technical features of this specification can be implemented based on a computer-readable medium (CRM). For example, the CRM proposed by this specification is at least one computer-readable recording medium containing instructions that are executed by at least one processor.

[0427] The CRM may store instructions for performing operations including the steps of receiving an NDPA (Null Data Packet Announcement) frame from a transmitting STA (station); receiving an NDP frame from the transmitting STA; and transmitting a feedback frame to the transmitting STA. The instructions stored in the CRM of the present specification may be executed by at least one processor. At least one processor related to the CRM of the present specification may be the processor (111, 121) or the processing chip (114, 124) of FIG. 1, or the processor (610) of FIG. 14. Meanwhile, the CRM of the present specification may be the memory (112, 122) of FIG. 1, the memory (620) of FIG. 14, or a separate external memory / storage medium / disk, etc.

[0428] The technical features of this specification described above are applicable to various applications and business models. For example, the technical features described above can be applied to wireless communication in devices that support artificial intelligence (AI).

[0429] Artificial intelligence (AI) is the study of artificial intelligence or the methodologies for creating it, while machine learning (ML) defines various problems in the field of AI and studies the methodologies for solving them. Machine learning is also defined as an algorithm that improves performance on a task through consistent experience.

[0430] An artificial neural network (ANN) is a model used in machine learning. It can refer to a model with problem-solving capabilities, consisting of artificial neurons (nodes) formed by the connection of synapses to form a network. An ANN can be defined by the connection patterns between neurons in different layers, the learning process that updates model parameters, and the activation function that generates output values.

[0431] An artificial neural network may include an input layer, an output layer, and optionally one or more hidden layers. Each layer contains one or more neurons, and the artificial neural network may include synapses connecting neurons. In an artificial neural network, each neuron can output a function value of an activation function based on input signals, weights, and biases received through the synapses.

[0432] Model parameters are parameters determined through learning, including synaptic connection weights and neuron biases. Hyperparameters are parameters that must be set before learning in machine learning algorithms, including the learning rate, number of iterations, mini-batch size, and initialization function.

[0433] The goal of artificial neural network training can be seen as determining model parameters that minimize a loss function. The loss function can be used as an indicator for determining optimal model parameters during the artificial neural network training process.

[0434] Machine learning can be classified into supervised learning, unsupervised learning, and reinforcement learning depending on the learning method.

[0435] Supervised learning refers to a method for training an artificial neural network when given labels for the training data. The labels can refer to the correct answer (or output value) that the artificial neural network must infer when the training data is input to the artificial neural network. Unsupervised learning can refer to a method for training an artificial neural network when the training data is not given labels. Reinforcement learning can refer to a learning method in which an agent defined within a given environment is trained to select actions or action sequences that maximize the cumulative reward in each state.

[0436] Machine learning implemented with a deep neural network (DNN) containing multiple hidden layers among artificial neural networks is also called deep learning, and deep learning is a subset of machine learning. Hereinafter, the term "machine learning" is used to encompass deep learning.

[0437] Additionally, the above-described technical features can be applied to wireless communication of robots.

[0438] A robot can be defined as a machine that automatically performs or operates a given task based on its own capabilities. Specifically, a robot capable of perceiving its environment, making independent judgments, and performing actions can be called an intelligent robot.

[0439] Robots can be categorized into industrial, medical, household, and military applications based on their intended use or field. Robots are equipped with actuators or motors, enabling them to perform various physical actions, such as moving robot joints. Furthermore, mobile robots incorporate wheels, brakes, and propellers into their actuators, enabling them to move on the ground or fly in the air.

[0440] Additionally, the above-described technical features can be applied to devices that support extended reality.

[0441] Extended reality is a general term for virtual reality (VR), augmented reality (AR), and mixed reality (MR). VR technology presents real-world objects and backgrounds as CG images only, AR technology presents virtual CG images over images of real objects, and MR technology is a computer graphics technology that blends and combines virtual objects with the real world.

[0442] MR technology is similar to AR in that it presents both real and virtual objects simultaneously. However, while AR uses virtual objects to complement real objects, MR uses virtual and real objects on an equal footing.

[0443] XR technology can be applied to HMD (Head-Mount Display), HUD (Head-Up Display), mobile phones, tablet PCs, laptops, desktops, TVs, digital signage, etc., and devices to which XR technology is applied can be called XR devices.

[0444] The claims set forth in this specification may be combined in various ways. For example, the technical features of the method claims of this specification may be combined and implemented as a device, and the technical features of the device claims of this specification may be combined and implemented as a method. Furthermore, the technical features of the method claims and the technical features of the device claims of this specification may be combined and implemented as a device, and the technical features of the method claims and the technical features of the device claims of this specification may be combined and implemented as a method.

Claims

1. In a wireless LAN system, A step in which a receiving STA (station) receives an NDPA (Null Data Packet Announcement) frame from a transmitting STA; The step of the receiving STA receiving an NDP frame from the transmitting STA; and The receiving STA comprises a step of transmitting a feedback frame to the transmitting STA, The above NDPA frame includes first to third fields, The first field contains information on whether beamforming for spatial modulation is indicated, The second field contains information about the modulation order of the spatial modulation, and The third field contains information about the number of activated antenna elements for the spatial modulation. method.

2. In paragraph 1, When requesting information about the above spatial modulation multiple times at once, the NDPA frame further includes a fourth field, The fourth field contains information about the number of the second and third fields, The second and third fields are present in at least one STA information field of the NDPA frame based on the fourth field. method.

3. In paragraph 1, The above feedback frame includes the first to fourth fields and the fifth field, The first to fourth fields included in the feedback frame are included in a MIMO (Multi Input Multi Output) control field, The fifth field contains quantized information about the beamforming matrix for the spatial modulation. method.

4. In paragraph 3, When the number of the activated antenna elements is N and the modulation order of the spatial modulation is M, the number of the beamforming matrix is ​​2^M, the dimension of the beamforming matrix is ​​N x Nr, and the Nr is the number of receiving antennas of the receiving STA, The fifth field includes a compressed beamforming report field for each of the beamforming matrices. method.

5. In paragraph 1, The above feedback frame is configured based on the above NDPA frame and the above NDP frame. method.

6. In paragraph 1, The receiving STA further includes a step of receiving beamformed data from the transmitting STA, The above beamformed data is generated by applying the spatial modulation based on the above feedback frame. method.

7. In a wireless LAN system, a receiving STA (station) memory; transceiver; and A processor operatively coupled to the memory and the transceiver, the processor comprising: Receive an NDPA (Null Data Packet Announcement) frame from a transmitting STA; Receive an NDP frame from the transmitting STA; and Transmit a feedback frame to the above transmitting STA, The above NDPA frame includes first to third fields, The first field contains information on whether beamforming for spatial modulation is indicated, The second field contains information about the modulation order of the spatial modulation, and The third field contains information about the number of activated antenna elements for the spatial modulation. Receiving STA.

8. In a wireless LAN system, A step in which a transmitting STA (station) transmits an NDPA (Null Data Packet Announcement) frame to a receiving STA; The step of the transmitting STA transmitting an NDP frame to the receiving STA; and The transmitting STA comprises a step of receiving a feedback frame from the receiving STA, The above NDPA frame includes first to third fields, The first field contains information on whether beamforming for spatial modulation is indicated, The second field contains information about the modulation order of the spatial modulation, and The third field contains information about the number of activated antenna elements for the spatial modulation. method.

9. In paragraph 8, When requesting information about the above spatial modulation multiple times at once, the NDPA frame further includes a fourth field, The fourth field contains information about the number of the second and third fields, The second and third fields are present in at least one STA information field of the NDPA frame based on the fourth field. method.

10. In paragraph 8, The above feedback frame includes the first to fourth fields and the fifth field, The first to fourth fields included in the feedback frame are included in a MIMO (Multi Input Multi Output) control field, The fifth field contains quantized information about the beamforming matrix for the spatial modulation. method.

11. In paragraph 10, When the number of the activated antenna elements is N and the modulation order of the spatial modulation is M, the number of the beamforming matrix is ​​2^M, the dimension of the beamforming matrix is ​​N x Nr, and the Nr is the number of receiving antennas of the receiving STA, The fifth field includes a compressed beamforming report field for each of the beamforming matrices. method.

12. In paragraph 8, The above feedback frame is configured based on the above NDPA frame and the above NDP frame. method.

13. In paragraph 8, The transmitting STA further includes a step of transmitting beamformed data to the receiving STA, The above beamformed data is generated by applying the spatial modulation based on the above feedback frame. method.

14. In a wireless LAN system, a transmitting STA (station) memory; transceiver; and A processor operatively coupled to the memory and the transceiver, the processor comprising: Transmit an NDPA (Null Data Packet Announcement) frame to the receiving STA; Transmitting an NDP frame to the receiving STA; and Receive a feedback frame from the receiving STA, The above NDPA frame includes first to third fields, The first field contains information on whether beamforming for spatial modulation is indicated, The second field contains information about the modulation order of the spatial modulation, and The third field contains information about the number of activated antenna elements for the spatial modulation. Transmitting STA.

15. At least one computer-readable medium containing instructions based on being executed by at least one processor, A step of receiving an NDPA (Null Data Packet Announcement) frame from a transmitting STA (station); A step of receiving an NDP frame from the transmitting STA; and A step of transmitting a feedback frame to the transmitting STA, The above NDPA frame includes first to third fields, The first field contains information on whether beamforming for spatial modulation is indicated, The second field contains information about the modulation order of the spatial modulation, and The third field contains information about the number of activated antenna elements for the spatial modulation. Recording medium.

16. In a wireless LAN system, in the device, memory; and A processor operatively coupled to the memory, the processor comprising: Receive an NDPA (Null Data Packet Announcement) frame from a transmitting STA (station); Receive an NDP frame from the transmitting STA; and Transmit a feedback frame to the above transmitting STA, The above NDPA frame includes first to third fields, The first field contains information on whether beamforming for spatial modulation is indicated, The second field contains information about the modulation order of the spatial modulation, and The third field contains information about the number of activated antenna elements for the spatial modulation. device.

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