Configuration of frame format for long range communication
The ELR PPDU structure addresses the power imbalance issue in wireless LAN systems by replicating the ELR-SIG field in the frequency domain, enhancing transmission range and ensuring reliable communication across access points and non-access point stations.
Patent Information
- Application Number
- PCT/KR2025/008788
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- Priority Date
- 2024-08-09
- Filing Date
- 2025-06-24
- Publication Date
- 2026-01-22
Smart Images

Figure KR2025008788_22012026_PF_FP_ABST
Abstract
Description
Composition of frame format for long-distance communication
[0001] This specification relates to a wireless LAN system, and more specifically, to a method and device for improving the structure of a frame format related to long-range communication in a wireless LAN system.
[0002] Wireless local area networks (WLANs) have been improved in various ways. For example, the Extreme High Throughput (EHT) standard can utilize newly proposed increased bandwidth, an improved PHY layer protocol data unit (PPDU) structure, improved sequences, and the Hybrid Automatic Repeat Request (HARQ) technique.
[0003] For example, a new standard that further improves the EHT standard is called the Ultra High Reliability (UHR) standard. The UHR standard may also be referred to as IEEE 802.11bn or WIFI 8. For example, the UHR standard may propose technical features that improve data rates even at low signal-to-interference-plus-noise ratio (SINR) levels. Furthermore, the UHR standard may propose technical features that minimize latency and jitter even in scenarios with mobility and overlapping BSSs. Furthermore, the UHR standard may propose technical features for wireless medium reuse.
[0004] For example, the UHR standard may propose a new frame structure or PPDU format. For example, a PPDU format designed to address the problem of transmission power imbalance between uplink and downlink may be discussed in UHR systems.
[0005] A wireless LAN system can operate with various STAs, including access points (APs) and non-AP STAs (stations). Typically, the TX power of an AP is greater than that of a non-AP STA. This difference in TX power can result in a difference between the downlink and uplink signal transmission ranges in a wireless LAN system.
[0006] To overcome these signal transmission range differences, a new physical protocol data unit (PPDU) structure could be proposed. These PPDUs could incorporate a frame structure designed to increase signal transmission range. For example, improved frequency mapping techniques, such as those in the PPDU's data field, may be required to increase signal transmission range.
[0007] Furthermore, to accurately decode PPDU data fields, a new signal field containing information for PPDU interpretation needs to be defined. This newly defined signal field should offer various technical features for long-distance communication. Furthermore, the position of this newly defined signal field among other existing fields (e.g., LTF, STF, Legacy Signal, etc.) should be discussed. Furthermore, various technical features applicable to new PPDUs for long-distance communication should be discussed.
[0008] The present disclosure may propose a method for transmitting / receiving a physical protocol data unit (PPDU) with an improved structure and a device related thereto.
[0009] Among the various examples of this specification, a PPDU that can increase the transmission range may be related to LR (long range), ER (extended range), and ELR (enhanced long range or extended long range) communication. An STA (station) related to this specification may generate an ELR PPDU including a data field. For example, the bandwidth of the ELR PPDU may be 20 MHz. For example, the data field may be transmitted through four 52-tone RUs (resource units) duplicated in the frequency domain in units of 52-tone RUs. For example, the ELR PPDU of this specification may further include an LTF signal.
[0010] The ELR PPDU may include an L-SIG (legacy signal) field including information related to the length of the ELR PPDU and a U-SIG (universal signal) field including information for interpreting the ELR PPDU.
[0011] For example, the L-SIG field, the RL-SIG field, and the U-SIG field may be generated based on the first subcarrier frequency spacing.
[0012] For example, the ELR PPDU may further include an STF (Short Training Field), an LTF (Long Training Field), an ELR-SIG (ELR Signal) field, and a data field.
[0013] For example, the STF, the LTF, the ELR-SIG field, and the data field may be generated based on the second subcarrier frequency spacing.
[0014] For example, the ELR-SIG field may be transmitted via four 52-tone resource units (RUs) duplicated in the frequency domain.
[0015] An example of this specification proposes an improved structure for an ELR PPDU. For example, according to an example of this specification, an improved frequency mapping technique is proposed in which RUs of a specific size are repeated. Based on this, the transmission range of the PPDU can be increased. For example, the frequency mapping technique for a specific field included in the PPDU can be improved. For example, data bits for a data field can be replicated in units of RUs of a specific size, and improved performance phase rotation can be applied to multiple replicated RUs.
[0016] An example of the present specification proposes a new signal field that includes various information related to ELR PPDU and / or ELR communication. The signal field may have various names, such as the ELR-SIG field. The ELR-SIG field may include a portion of information included in the existing L-SIG, RL-SIG, and U-SIG fields. For example, the ELR-SIG field may be proposed in preparation for cases where the existing L-SIG, RL-SIG, and U-SIG fields are not successfully received by a receiving STA due to a UL / DL power imbalance issue. To this end, the ELR-SIG field may be replicated in the frequency domain in units of a specific size of RU (e.g., 52-tone RU), unlike the existing L-SIG, RL-SIG, and U-SIG fields. For example, the ELR PPDU of this specification includes the existing L-SIG, RL-SIG, and U-SIG fields, but there is no need for the fields to be repeated in the time domain or duplicated in the frequency domain. In other words, the ELR PPDU of this specification proposes a technique that proposes the performance of ELR-SIG without increasing the overhead of the existing L-SIG, RL-SIG, and U-SIG fields.
[0017] For example, the ELR-SIG may have the same OFDM numerology as the ELR-Data field, since it is replicated in the frequency domain, similar to the ELR-Data field. Additionally or alternatively, the ELR-SIG may be placed immediately after the STF / LTF included in the UHR PPDU to achieve the technical effects of synchronization / channel estimation / CFO achieved through the STF / LTF.
[0018] Additionally, the ELR-SIG of this specification may include various optimized fields related to the ELR PPDU so that the ELR PPDU can be received even in situations where the existing L-SIG, RL-SIG, and U-SIG fields are not duplicated.
[0019] Figure 1 illustrates an example of a transmitting device and / or a receiving device of the present specification.
[0020] Figure 2 is a conceptual diagram showing the structure of a wireless local area network (WLAN).
[0021] Figure 3 is a diagram illustrating a general link setup process.
[0022] Figure 4 illustrates one embodiment of a multi-link (ML).
[0023] Figure 5 illustrates a PPDU transmitted / received by an STA of this specification.
[0024] Figure 6 is a diagram showing the layout of resource units (RUs) used for 20MHz PPDU.
[0025] Figure 7 is a diagram showing the layout of resource units (RUs) used for 40MHz PPDU.
[0026] Figure 8 is a diagram showing the layout of resource units (RUs) used for 80MHz PPDU.
[0027] Figure 9 shows the operation according to UL-MU.
[0028] Figure 10 shows an example of channels used / supported / defined within the 2.4 GHz band.
[0029] Figure 11 illustrates an example of channels used / supported / defined within the 5 GHz band.
[0030] Figure 12 illustrates an example of channels used / supported / defined within the 6 GHz band.
[0031] Figure 13 shows an example of a header of a MAC frame.
[0032] FIG. 14 illustrates a modified example of a transmitting device and / or a receiving device of the present specification.
[0033] Figure 15 shows an example of a PPDU proposed in this specification.
[0034] Figure 16 shows an example of the legacy preamble of this specification.
[0035] Figure 17 shows an example of a number of fields / subfields that may be included in an ELR preamble.
[0036] Figure 18 illustrates replication in the frequency domain applicable to ELR-SIG.
[0037] Figure 19 shows an example of an ELR PPDU of this specification.
[0038] Figure 20 is a diagram showing four 52-tone RUs included in an ELR PPDU.
[0039] Figure 21 is an example of a procedure flowchart related to this specification.
[0040] Figure 22 is an example of a procedure flowchart related to this specification.
[0041] As used herein, "A or B" can mean "only A," "only B," or "both A and B." In other words, as used herein, "A or B" can be interpreted as "A and / or B." For example, as used herein, "A, B or C" can mean "only A," "only B," "only C," or "any combination of A, B and C."
[0042] As used herein, a slash ( / ) or a comma can mean "and / or." For example, "A / B" can mean "A 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."
[0043] In this specification, "at least one of A and B" may mean "only A", "only B" or "both A and B". Additionally, in this specification, the expressions "at least one of A or B" or "at least one of A and / or B" may be interpreted identically to "at least one of A and B".
[0044] In addition, parentheses used in this specification may mean "for example". Specifically, when it is indicated as "control information (UHR-Signal field)", the "UHR-Signal field" may be proposed as an example of "control information". In other words, the "control information" in this specification is not limited to the "UHR-Signal field", and the "UHR-Signal field" may be proposed as an example of "control information". In addition, even when it is indicated as "control information (UHR-Signal field)", the "UHR-Signal field" may be proposed as an example of "control information".
[0045] 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."
[0046] 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".
[0047] Technical features individually described in a single drawing in this specification may be implemented individually or simultaneously.
[0048] 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 following examples of this 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 following examples of this specification can be applied to mobile communication systems based on the Long Term Evolution (LTE) and its evolution based on the 3rd Generation Partnership Project (3GPP) standard.
[0049] In order to explain the technical features of this specification, the technical features to which this specification can be applied are described below.
[0050] Figure 1 illustrates an example of a transmitting device and / or a receiving device of the present specification.
[0051] 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.
[0052] 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.
[0053] 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).
[0054] 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.
[0055] Based on the sub-drawing (a) of Fig. 1, STA (110, 120) is described as follows.
[0056] 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.
[0057] 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.).
[0058] 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 (e.g., a received signal) received through the transceiver (113) and store a signal (e.g., a transmitted signal) to be transmitted through the transceiver.
[0059] 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.).
[0060] 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 (e.g., a reception signal) received through the transceiver (123) and store a signal (e.g., a transmission signal) to be transmitted through the transceiver.
[0061] 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).
[0062] 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).
[0063] 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 for generating a transmission / reception signal or performing data processing or operation in advance for a transmission / reception signal may include 1) an operation for determining / obtaining / configuring / computing / decoding / encoding bit information of a subfield (SIG, STF, LTF, Data) field included in a PPDU, 2) an operation for 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 for 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.
[0064] 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.
[0065] 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.
[0066] 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.
[0067] 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.
[0068] 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.
[0069] 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 EXYNOS® 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.
[0070] 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.
[0071] Figure 2 is a conceptual diagram showing the structure of a wireless local area network (WLAN).
[0072] 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.
[0073] 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).
[0074] The BSS may include at least one STA, an AP (225, 230) providing a distribution service, and a distribution system (DS, 210) connecting multiple APs.
[0075] 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).
[0076] 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).
[0077] 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).
[0078] The bottom of Figure 2 is a conceptual diagram showing IBSS.
[0079] 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.
[0080] Figure 3 is a diagram illustrating a general link setup process.
[0081] 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.
[0082] 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 (e.g., transmitting and receiving probe requests / responses on channel 2) in the same manner.
[0083] 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.
[0084] 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.
[0085] 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.
[0086] 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.
[0087] 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.
[0088] 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.
[0089] Figure 4 illustrates one embodiment of a multi-link (ML).
[0090] 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 (e.g., AP STAs), and the non-AP MLD can include affiliated STAs (e.g., non-AP STAs, or user-STAs).
[0091] 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.
[0092] 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.
[0093] In the example of FIG. 4, AP1 can 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 can 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 (e.g., user-STA or non-AP STA) illustrated in FIG. 1 and / or FIG. 2.
[0094] 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.
[0095] FIG. 5 illustrates a PPDU (physical protocol data unit or physical layer (PHY) protocol data unit) transmitted / received by an STA of this specification.
[0096] 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.
[0097] 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.
[0098] 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).
[0099] 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.
[0100] 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.
[0101] 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).
[0102] 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.
[0103] 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}.
[0104] 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.
[0105] 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.
[0106] 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 μs. 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.
[0107] 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 (e.g., BCC encoding) based on a rate of R=1 / 2 to generate 52 coded bits, and perform interleaving on the 52 coded bits. The transmitting STA can perform BPSK modulation on the interleaved 52 coded bits to generate 52 BPSK symbols 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.
[0108] 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".
[0109] 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.
[0110] 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.
[0111] 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.
[0112] 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.
[0113] For example, the version-independent bits of U-SIG may contain information about the length of the TXOP and information about the BSS color ID.
[0114] 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.
[0115] For example, U-SIG may include 1) a bandwidth field including information about bandwidth, 2) a field including information about a Modulation and Coding Scheme (MCS) technique applied to UHR-SIG, 3) an indication field including information about whether a dual subcarrier modulation (DCM) technique is applied to UHR-SIG, 4) a field including information about the number of symbols used for UHR-SIG, 5) a field including information about whether 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 UHR-LTF and the CP length.
[0116] 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 may apply puncturing to the secondary 20 MHz band within the 80 MHz band, and transmit the PPDU only through the primary 20 MHz band and the secondary 40 MHz band.
[0117] 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.
[0118] 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.
[0119] 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-SIGs 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 (e.g., information regarding a preamble puncturing pattern). Additionally, the first field of the second U-SIG may include information regarding a 160 MHz bandwidth, and the second field of the second U-SIG may include information regarding preamble puncturing applied to the second 80 MHz band (e.g., information regarding a preamble puncturing pattern). Meanwhile, the UHR-SIG consecutive to the first U-SIG may include information regarding preamble puncturing applied to the second 80 MHz band (e.g., information regarding a preamble puncturing pattern), and the UHR-SIG consecutive to the second U-SIG may include information regarding preamble puncturing applied to the first 80 MHz band (e.g., information regarding a preamble puncturing pattern).
[0120] 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 (e.g., 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 (e.g., information regarding preamble puncturing patterns).
[0121] 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.
[0122] The UHR-SIG of FIG. 5 may include control information for a receiving STA. The UHR-SIG may be transmitted over at least one symbol, and each symbol may have a length of 4 μs. Information regarding the number of symbols used for the UHR-SIG may be included in the U-SIG.
[0123] 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 (e.g., UHR modulated fields of an UHR PPDU).
[0124] 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.
[0125] 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.
[0126] As shown at the top of Fig. 6, 26 units (e.g., units corresponding to 26 tones) may be arranged. Six tones may be used as a guard band in the leftmost band of the 20 MHz band, and five tones may be used as a guard band in the rightmost band of the 20 MHz band. In addition, seven DC tones may be inserted in the center band, i.e., the DC band, and 26 units corresponding to 13 tones may exist on each side of the DC band. In addition, 26 units, 52 units, and 106 units may be allocated to other bands. Each unit may be allocated for a receiving station, i.e., a user.
[0127] 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.
[0128] 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 sizes of each RU (e.g., 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.
[0129] Figure 7 is a diagram showing the layout of resource units (RUs) used for 40MHz PPDU.
[0130] 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.
[0131] 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.
[0132] 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.
[0133] Figure 9 illustrates an operation according to UL-MU. As illustrated, a transmitting STA (e.g., AP) can acquire a TXOP (925) by performing channel access through contending (e.g., backoff operation) and transmit a trigger frame (930). That is, the transmitting STA (e.g., AP) can 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.
[0134] 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. For example, the ACK frame (950) for the TB PPDU can be implemented in the form of a BA (block ACK).
[0135] In FIG. 9, transmission(s) of a Trigger Frame (930), TB PPDU (941, 942) and / or ACK frame (950) can be performed within a TXOP (925).
[0136] Figure 10 shows an example of channels used / supported / defined within the 2.4 GHz band.
[0137] 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.
[0138] 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.
[0139] 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.
[0140] Figure 11 illustrates an example of channels used / supported / defined within the 5 GHz band.
[0141] 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.
[0142] 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.
[0143] 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.
[0144] Figure 12 illustrates an example of channels used / supported / defined within the 6 GHz band.
[0145] 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.
[0146] 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.
[0147] 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.
[0148] Below, the structure and types / subtypes of MAC frames are described.
[0149] 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.
[0150] 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.
[0151] 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.
[0152] 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).
[0153] 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).
[0154] 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.
[0155] The MAC frame / signal used in this specification can be identified through the type field / information and subtype field / information described above. For example, the "trigger 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, B4 bits in the frame control field are also 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).
[0156] FIG. 14 illustrates a modified example of a transmitting device and / or a receiving device of the present specification.
[0157] 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.
[0158] 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.
[0159] 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.
[0160] 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.
[0161] 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).
[0162] The wireless LAN system (e.g., IEEE 802.11bn or UHR system) related to this specification aims to support ultra-high reliability in signal transmission to STAs. To this end, various technologies are being considered for high throughput, low latency, and extended range support. Based on these various technologies, a method for extending the range of signal transmission may be possible to expand not only reliability within the BSS but also signal transmission coverage of the BSS. The following technical features are related to proposing a new structure (or type) of frame (or PPDU / preamble) for extended range (ER) communication in a wireless LAN system.
[0163] A device (e.g., non-AP STA, AP, non-AP MLD, AP, MLD) based on the present specification may support a new ELR (extended long range or enhanced long range) PPDU designed to overcome link budget imbalances between uplink and downlink and improve spectral efficiency of STAs operating far from the AP. The term ELR may be replaced with terms such as LR (long range) or ER (extended range). Accordingly, terms such as ER transmission or LR transmission may be expressed as ELR transmission. For example, in the examples below, an LR PPDU may also be referred to as an ER PPDU or an ELR PPDU. For example, an ELR PPDU has a fixed bandwidth of 20 MHz and can be used for both downlink and uplink in 2.4 GHz band operation, but can be used only for uplink in 5 GHz and 6 GHz band operation. In other words, ELR PPDU may consist of only 20 MHz and may not have bandwidths such as 40 / 80 / 160 / 320 MHz.
[0164] As described above, in a wireless LAN system (e.g., IEEE 802.11bn or UHR system), LR / ER / ELR communication can be considered to ensure smooth signal transmission and reception for STAs located within the coverage boundary of the AP and to overcome the transmission range difference caused by the transmission power difference between the AP and the STA. For example, the difference in transmission power between the AP and non-AP STAs can be about 10 dB. For example, the link budget for the received signal between the AP and non-AP STAs due to this TX power difference can be about 6 dB. For example, long-range transmission to provide a gain of 6 dB, which is the link budget difference, can be performed using the following method.
[0165] Figure 15 illustrates an example of a PPDU proposed in this specification. The example of Figure 15 may be referred to by various names. For example, it may be referred to by various names such as ELR PPDU, ER PPDU, LR PPDU, etc. Or it may be referred to by various names such as UHR PPDU, UHR ELR PPDU, etc.
[0166] For example, the example of FIG. 15 can be generated to provide a 6 dB gain, which is the link budget difference described above. The example of FIG. 15 can be used for uplink, but can also be used for downlink (e.g., downlink within the 2.4 GHz band).
[0167] For example, the bandwidth of the example of Fig. 15 can be 40 / 80 / 160 / 320 MHz. However, considering that the example of Fig. 15 is used for ELR communication, it is desirable to transmit and receive based on a bandwidth of 20 MHz. That is, in order to obtain additional gain (e.g., a gain of 6 dB, which is the link budget difference), the example of Fig. 15 is preferably used for narrow band communication.
[0168] An example of FIG. 15 may include a legacy preamble (1510). For example, the legacy preamble (1510) may include L-STF, L-LTF, L-SIG, and U-SIG. For example, the legacy preamble (1510) may be configured based on 1x (OFDM) numerology. In other words, the value of the subcarrier frequency spacing of each field included in the legacy preamble (1510) may be 312.5 kHz. The name of the legacy preamble (1510) may be modified in various ways.
[0169] Fig. 16 illustrates an example of a legacy preamble (1510) of the present specification. As illustrated, the legacy preamble (1510) may include an L-STF (1610), an L-LTF (1620), an L-SIG (1630), and a RL-SIG (1640). In addition, although not illustrated in Fig. 16, a U-SIG field consecutive to the RL-SIG (1640) may also be additionally included.
[0170] For example, the L-STF (1610) and L-LTF (1620) illustrated in FIG. 16 can be configured based on the same sequence as the L-STF and L-LTF described in FIG. 5. Additionally or alternatively, power boosting of 3 / 4 / 5 / 6 dB can be applied to the L-STF (1610) and L-LTF (1620).
[0171] For example, the L-SIG (1630) illustrated in FIG. 16 may be repeated in the time domain. For example, the RL-SIG (1640) may be a repetition of the L-SIG (1630). Although one L-SIG (1630) and one RL-SIG (1640) are illustrated in the PPDU of FIG. 16, an additional RL-SIG may be included. The RL-SIG (1640) may be continuous with the L-SIG (1630). For example, power boosting of 3 / 4 / 5 / 6 dB may not be necessary for the L-SIG (1630) and the RL-SIG (1640). This is because the content of the L-SIG (1630) is repeated in the time domain.
[0172] For example, the L-SIG (1630) and the RL-SIG (1640) illustrated in FIG. 16 may be configured identically to the L-SIG and RL-SIG of FIG. 5.
[0173] For example, if an ELR PPDU is configured including RL-SIG (1640), an STA (e.g., non-AP STA or AP) that receives the PPDU can determine that the received PPDU is a PPDU of version 11ax or higher through the L-SIG repetition check. In addition, the value of length%3 of RL-SIG (1640) can determine whether the PPDU is 11ax or 11be / UHR / next version.
[0174] In other words, the RL-SIG (1640) field is a repeat of the L-SIG (1630) field and is used to differentiate an UHR PPDU from a non-HT PPDU, HT PPDU, and VHT PPDU.
[0175] Additionally or alternatively, the legacy preamble (1510) may include a U-SIG, through which protection for legacy STAs (e.g., 11be or EHT STAs) may be performed.
[0176] For example, the U-SIG included in the legacy preamble (1510) may be based on the U-SIG of FIG. 5. For example, the U-SIG included in the legacy preamble (1510) may be continuous with the RL-SIG (1640), similar to the U-SIG of FIG. 5. The U-SIG included in the legacy preamble (1510) may include a 3-bit long PHY version identifier (information / field), similar to the U-SIG of FIG. 5. The value of the PHY version identifier (information / field) may be set to one (1) to indicate that the legacy preamble (1510) is related to a UHR PPDU. In other words, based on the fact that the value of the PHY version identifier (information / field) is set to one (1), it may be indicated that the PPDU being received / transmitted is a UHR PPDU, an ELR PPDU, or a UHR ELR PPDU.
[0177] For example, the U-SIG included in the legacy preamble (1510) may include PPDU Type And Compression Mode (e.g., 2 bits), similar to the U-SIG of FIG. 5. For example, the 2-bit field / bit (e.g., PPDU Type And Compression Mode) may be used to indicate ELR transmission. Specifically, for the same indication in DL and UL transmission, the value of the PPDU Type And Compression Mode may be set to 3.
[0178] For example, the U-SIG included in the legacy preamble (1510) may include TXOP information, similarly to the U-SIG of FIG. 5. Accordingly, an STA (e.g., non-AP or AP) that receives a PPDU (e.g., ELR PPDU) including the legacy preamble (1510) may set a NAV based on the TXOP information if it is not the intended STA. Through this, the STA may perform power saving (and / or protection for ELR transmission in progress between other STAs).
[0179] The U-SIG included in the legacy preamble (1510) (in other words, the U-SIG included in the ELR PPDU) may include various bits / subfields. More specific characteristics regarding the bits / subfields included in the U-SIG are described with reference to FIG. 19. That is, the U-SIG described in FIG. 19 may be the same as the U-SIG included in the legacy preamble (1510) (in other words, the U-SIG included in the ELR PPDU).
[0180] Below, the ELR preamble (1510) of FIG. 15 is explained with reference to FIG. 17.
[0181] Fig. 17 shows an example of a plurality of fields / subfields that may be included in an ELR preamble. For example, as illustrated in Fig. 15, an ELR preamble (1520) may be continuous with the legacy preamble (1510). For example, as illustrated in Fig. 15, a plurality of fields that may be included in the ELR preamble (1520) may be configured based on 4x (OFDM) numerology, unlike the legacy preamble (1510). In other words, the value of the subcarrier frequency spacing of each field included in the ELR preamble (1520) may be 78.125 kHz. The name of the ELR preamble (1520) may be modified in various ways.
[0182] For example, the ELR preamble (1520) may include an ELR-STF (1710), an ELR-LTF (1720), and an ELR-SIG (1730). The ELR-STF (1710) may be continuous to the ELR-LTF (1720), and the ELR-LTF (1720) may be continuous to the ELR-SIG (1730). For example, the fields included in the ELR preamble (1520) may be limited to only the three fields (ELR-STF (1710), ELR-LTF (1720), and ELR-SIG (1730)) illustrated in FIG. 17.
[0183] For example, ELR-STF (1710) can be configured based on HE / EHT-STF. For example, ELR-STF can be configured based on the sequence below.
[0184] [Formula 1]
[0185] UHRS_{-112 : 16 : 112} = M · (1+j) / ( )
[0186] The value of STF sequence at null tone index 0 is zero.
[0187] M = {-1, -1, -1, 1, 1, 1, -1, 1, 1, 1, -1, 1, 1, -1, 1}
[0188] As in the above equation 1, ERL-STF (1710) can be generated / configured / defined based on an STF sequence expressed in UHRS. For example, the lowest tone / subcarrier index of the STF sequence of equation 1 is -112, and the highest tone / subcarrier index is +112. For example, the STF sequence of equation 1 can have values / coefficients at 16 tone / subcarrier intervals. For example, the STF sequence of equation 1 is defined based on an M sequence, and the M sequence can be a sequence having 15 elements / values / coefficients as in equation 1.
[0189] For example, the ERL-STF (1710) can be configured to repeat a 0.8 μs sequence, similar to the legacy STF described in Fig. 5. Using the STF sequence configured as described above, the ELR-STF can be configured / defined / transmitted as an 8 μs symbol.
[0190] For example, the ELR-STF (1710) can be modified in various ways. For example, the generated 0.8 μs sequence can be included / repeated 5 times, and thus the ELR-STF can be composed / defined / transmitted as a 4 μs symbol.
[0191] Although Equation 1 above describes an example in which value / coefficient is defined with a 16 tone / subcarrier interval, an 8 tone / subcarrier interval can be used instead of a 16 tone / subcarrier interval. The 1.6 μs unit sequence generated based on this can be repeated 5 or 10 times, ultimately forming an ELR-STF (1710) based on an 8 μs or 16 μs duration. The above can be expressed as a formula as follows.
[0192] [Formula 2]
[0193] UHRS_{-120 : 8: 120} = {M, 0, -M} · (1+j) / ( )
[0194] M = {-1, -1, -1, 1, 1, 1, -1, 1, 1, 1, -1, 1, 1, -1, 1}
[0195] For example, ELR-LTF (1710) can be configured based on HE / EHT-LTF. For example, ELR-LTF (1710) can be configured / defined / generated based on various LTF sequences. For example, ELR-LTF (1710) can be based on 4x LTF sequence among 1x, 2x, and 4x LTF sequences. Since ELR PPDU is transmitted and received based on one SS, if ELR-LTF (1710) is configured / generated based on 4x LTF sequence, the corresponding LTF can be configured as one OFDM symbol.
[0196] For example, if a 4x LTF sequence is used, the performance of channel estimation using LTF can be expected to improve because coefficients / values are defined for all frequency indices / tones. However, an example of the present specification may propose configuring an ELR-LTF (1710) based on a 2x LTF sequence. In a 2x LTF sequence, coefficients / values can be defined only for even frequency indices / tones. When a Fourier transform is performed on the sequence, a signal in which the same sequence is repeated within one symbol in the time domain can be generated. If such a signal is transmitted twice through two symbols in the time domain, the receiving STA can obtain sufficient channel estimation performance. That is, the performance of channel estimation can be improved by transmitting an LTF signal that is repeated through two 8 μs symbols, rather than sending only one 8 μs symbol generated based on a 2x LTF sequence.
[0197] For example, although the coefficients / values of a 2x LTF sequence are not defined for all frequency indices / tones, they can support channel estimation through interpolation for odd indices / tones. Accordingly, if an 8 μs symbol generated based on a 2x LTF sequence is transmitted twice (e.g., repeatedly transmitted in the time domain), a maximum-ratio combining (MRC) gain can be obtained compared to a 16 μs symbol based on a 4x LTF sequence transmitted once, thereby further improving the performance of channel estimation.
[0198] For example, the ELR-LTF (1710) can be configured based on various 2x LTF sequences. For example, the ELR-LTF (1710) can be generated based on the following sequence.
[0199] 2x LTF = {-1, 0, -1, 0, -1, 0, +1, 0, +1, 0, -1, 0, +1, 0, -1, 0, -1, 0, -1, 0, -1, 0, +1, 0, -1, 0, +1, 0, -1, 0, -1, 0, +1, 0, +1, 0, -1, 0, +1, 0, +1, 0, +1, 0, +1, 0, +1, 0, -1, 0, +1, 0, -1, 0, +1, 0, -1, 0, -1, 0, +1, 0, +1, 0, -1, 0, +1, 0, -1, 0, -1, 0, -1, 0, -1, 0, +1, 0, -1, 0, +1, 0, +1, 0, +1, 0, -1, 0, -1, 0, +1, 0, -1, 0, -1, 0, -1, 0, -1, 0, -1, 0, -1, 0, -1, 0, +1, 0, -1, 0, -1, 0, +1, 0, -1, 0, -1, 0, +1, 0, +1, 0, +1, 0, -1, 0, -1, 0, +1, 0, 0, 0, +1, 0, -1, 0, +1, 0, +1, 0, -1, 0, +1, 0, +1, 0, -1, 0, +1, 0, +1, 0, -1, 0, +1, 0, +1, 0, -1, 0, +1, 0, -1, 0, +1, 0, +1, 0, -1, 0, -1, 0, +1, 0, -1, 0, -1, 0, -1, 0, -1, 0, -1, 0, -1, 0, -1, 0, +1, 0, -1, 0, +1, 0, -1, 0, +1, 0, +1, 0, -1, 0, -1, 0, +1, 0, -1, 0, +1, 0, -1, 0, -1, 0, -1, 0, +1, 0, -1, 0, +1, 0, -1, 0, +1, 0, -1, 0, -1, 0, -1, 0, -1, 0, -1, 0, -1, 0, +1, 0, -1, 0, +1}
[0200] For the proposed ELR-LTF (1710), a GI of 3.2 μs is applied. For example, a GI of 3.2 μs is not necessarily required and a GI of 1.6 μs may also be used.
[0201] Similar to L-STF and L-LTF, power boosting of 3 / 4 / 5 / 6 dB can be applied to the above-described ELR-STF (1710) and / or ELR-LTF (1720). Through this, the receiving STA can normally receive the corresponding ELR-STF (1710) and / or ELR-LTF (1720).
[0202] Below is a description of ELR-SIG (1730).
[0203] For example, the ELR-SIG (1730) may be included in the ELR preamble (1520). For example, the ELR-SIG (1730) may be present after the ELR-LTF (1720). In other words, the ELR-SIG (1730) may be continuous with the ELR-LTF (1720).
[0204] For example, ELR-SIG (1730) can be composed of two symbols. For example, ELR-SIG (1730) can include various information related to ELR communication (e.g., various information for interpretation / decoding / demodulation of data fields and / or ELR PPDU). Examples of various subfields / bits that can be included in ELR-SIG (1730) are described in more detail in FIG. 19.
[0205] For the ELR-SIG (1730) of this specification, it is preferable that duplication be performed in the frequency domain in units of 52-tone RU / subcarriers according to the following technique. For example, it is preferable that duplication in the frequency domain applied to the ELR-SIG (1730) is applied identically to the ELR Data (1530). For example, the 52-tone RU that serves as a reference when duplication is performed in the frequency domain may be identical to the 52-tone RU defined in IEEE 802.11ax / be. More specific features regarding this 52-tone RU may be described with reference to FIG. 18 and / or FIG. 20.
[0206] Figure 18 illustrates replication in the frequency domain applicable to ELR-SIG.
[0207] As illustrated, ELR-SIG is replicated in 52-tone RU units on the frequency domain. In other words, bit information transmitted and received through ELR-SIG can be mapped to one 52-tone RU. One 52-tone RU is repeated on the frequency domain. In the example of Fig. 18, the leftmost ELR-SIG can be replicated through three repeated ELR-SIGs (RELR-SIGs). That is, all four 52-tone RUs illustrated in Fig. 18 can be used to transmit and receive the same bit information (e.g., the same contents). For example, in addition to the four 52-tone RUs illustrated in Fig. 18, two 13-subcarriers and seven DC tones may not be used for ELR-SIG.
[0208] For example, the frequency mapping technique illustrated in FIG. 18 can be equally applied to ELR Data as well as ELR-SIG (1730).
[0209] For example, a limited MCS technique may be applied to the ELR-SIG (1730) and / or the ELR data field to which the technique of FIG. 18 is applied. For example, only the MCS technique associated with the MCS0 index (BPSK with 1 / 2 code rate) may be applied, or only the MCS technique associated with a preset MCS index (e.g., MCS1) may be applied.
[0210] For example, DC or null subcarriers may be included between the four 52-tone RUs illustrated in FIG. 18. Alternatively, the four 52-tone RUs illustrated in FIG. 18 may be arranged consecutively with each other.
[0211] As described above, by replicating ELR-SIG (1730) in the frequency domain based on 52 tones, a link budget gain of 6 dB can be achieved. In addition, the performance and reliability of the SIG field can be improved during long-range transmission.
[0212] Fig. 19 illustrates an example of an ELR PPDU of the present specification. As illustrated, an ELR PPDU (or a PPDU used for ELR communication) may include L-STF (1905), L-LTF (1910), L-SIG (1915), RL-SIG (1920), U-SIG (1925), ELR-MARK (1930), UHR-STF (1935), UHR-LTF (1940), ELR-SIG (1945), and Data (1950). For example, some fields of Fig. 19 may be omitted. For example, the order of some fields of Fig. 19 may be changed differently. Each field disclosed in Fig. 19 may be called by various names such as signal / bit.
[0213] The PPDU and / or fields of FIG. 19 are examples that further specify the examples of FIGS. 15 to 18. Accordingly, the technical features applied to FIG. 19 may include the technical features applied to the examples of FIGS. 15 to 18.
[0214] For example, L-STF (1905) to ELR-MARK (1930) of FIG. 19 may be included in Legacy Preamble (1510) of FIG. 15. For example, L-STF (1905) to RL-SIG (1920) of FIG. 19 may be identical to L-STF (1610) to RL-SIG (1640) of FIG. 16. For example, U-SIG (1925) of FIG. 19 may be identical to U-SIG included in FIG. 15 and / or FIG. 16.
[0215] The UHR-STF (1935), UHR-LTF (1940), and ELR-SIG (1945) of FIG. 19 may be included in the ELR Preamble (1520) of FIG. 15. In other words, the UHR-STF (1935) of FIG. 19 may be identical to the ELR-STF (1710) described above. In other words, the UHR-LTF (1940) of FIG. 19 may be identical to the ELR-LTF (1920) described above. In other words, the ELR-SIG (1945) of FIG. 19 may be identical to the ELR-SIG (1730) of FIG. 17.
[0216] Data (1950) of Fig. 19 may be identical to ELR Data (1530) of Fig. 15.
[0217] As described above, the value of the number of spatial streams (e.g., Nss) for the ELR PPDU of the present specification may be limited to 1. Additionally or alternatively, for example, the ELR PPDU has a fixed bandwidth of 20 MHz and can be used for both downlink and uplink in 2.4 GHz band operation, but can be used only for uplink in 5 GHz and 6 GHz band operation. In other words, the ELR PPDU may consist of only 20 MHz and may not have bandwidths such as 40 / 80 / 160 / 320 MHz.
[0218] For example, the ELR-MARK (1930) of FIG. 19 may be composed of two OFDM symbols. The ELR-MARK (1930) may include information about an identifier (e.g., BSS_COLOR) indicating the BSS color to which the STA transmitting the corresponding PPDU belongs.
[0219] For convenience of explanation, the technical characteristics of ELR PPDU are described in detail below, focusing on the above four fields / signals (1925, 1940, 1945, 1950).
[0220] For example, the U-SIG (1925) may have the following characteristics. For example, the U-SIG (1925) of the present specification may be composed of signals / fields for an ELR PPDU. For example, a PPDU other than an ELR PPDU (e.g., a UHR MU PPDU or a UHR TB PPDU) also contains a U-SIG, but the contents of the U-SIG (1925) of the present specification may contain different contents.
[0221] For example, the U-SIG (1925) of the present specification has a length of 2 symbols, and each symbol can be represented as U-SIG-1 and U-SIG-2. For example, the B0 bit to the B2 bit of the U-SIG-1 can have various names such as the first information described above or the PHY Version Identifier, and can include a value (e.g., a value of 1) that identifies that the PHY version of the PPDU is UHR. For example, the positions of the B0 bit to the B2 bit can be changed.
[0222] Additionally or alternatively, the B3 bits to the B5 bits of the U-SIG-1 may have various names such as the second information or the BW information, and may include information regarding the bandwidth of the ELR PPDU. For example, the B3 bits to the B5 bits of the U-SIG-1 may only have a value of 0. This is because the bandwidth of the ELR PPDU is preferably fixed to 20 MHz. For example, the positions of the B3 bits to the B5 bits may be changed.
[0223] Additionally or alternatively, the B6 bit of the U-SIG-1 may contain information regarding whether the PPDU is transmitted in the UL or DL. For example, the position of the B6 bit may be changed.
[0224] Additionally or alternatively, bits B7 to B12 of U-SIG-1 may indicate the ID of a Basic Service Set (BSS). For example, bits B7 to B12 may include ID information (or BSS color information) of a BSS to which an STA transmitting / receiving the corresponding PPDU belongs. For example, the positions of bits B7 to B12 may be changed.
[0225] Additionally or alternatively, bits B13 to B19 of U-SIG-1 may contain information related to the duration of a transmission opportunity (TXOP). For example, the positions of bits B13 to B19 may be changed.
[0226] Additionally or alternatively, bits B20 through B24 of U-SIG-1 may all be set to 1, and the bits may be referred to as disregard. For example, the positions of bits B20 through B24 may be changed.
[0227] Additionally or alternatively, the B25 bit of U-SIG-1 may be set to 1, and the bit may be called Validate. For example, the position of the B25 bit may be changed.
[0228] Additionally or alternatively, the B0 bit and the B1 bit of the U-SIG-2 may have various names such as the third information or PPDU Type And Compression Mode. The B0 bit and the B1 bit may always have a value of 3 regardless of whether the related PPDU is a DL PPDU or an UL PPDU, thereby indicating / identifying that the PPDU is an ELR PPDU. For example, the positions of the B0 bit and the B1 bit may be changed.
[0229] Additionally or alternatively, bits B2 to B12 of U-SIG-2 may be configured as an STA ID. For example, bits B2 to B12 may be configured as a portion of 11 bits (e.g., 11 bits of the LSB or 11 bits of the MSB) of the Association ID (AID) of the STA transmitting the corresponding PPDU. For example, the positions of bits B2 to B12 may be changed.
[0230] Additionally or alternatively, bits B13 to B15 of U-SIG-2 may be configured as ER / ELR validate. These three bits may be used to identify an ELR PPDU, and these three bits may all be set to 1 (i.e., these three bits have a value of 7). For example, the positions of bits B13 to B15 may be changed.
[0231] Additionally or alternatively, bits B16 to B19 of the U-SIG-2 may be configured as a CRC.
[0232] Additionally or alternatively, bits B20 through B25 of U-SIG-2 may be configured as a tail, such that all bits are zero.
[0233] For example, the above U-SIG1 and U-SIG2 may be repeated in the time domain based on at least one of FIGS. 15 to 18.
[0234] For example, the UHR-LTF (1940) may have the following characteristics. The UHR-LTF (1940) may be divided into signals for ELR communication and signals for non-ELR communication.
[0235] Additionally or alternatively, the UHR-LTF for the ELR communication may be configured based on a 2x LTF sequence. The 2x LTF sequence may be defined in the range of indices -122 to +122. The sequence may be expressed as follows.
[0236] 2x LTF = {-1, 0, -1, 0, -1, 0, +1, 0, +1, 0, -1, 0, +1, 0, -1, 0, -1, 0, -1, 0, +1, 0, -1, 0, +1, 0, -1, 0, -1, 0, +1, 0, +1, 0, -1, 0, +1, 0, +1, 0, +1, 0, +1, 0, +1, 0, -1, 0, +1, 0, -1, 0, +1, 0, -1, 0, +1, 0, +1, 0, -1, 0, +1, 0, -1, 0, -1, 0, -1, 0, -1, 0, -1, 0, -1, 0, -1, 0 0, +1, 0, +1, 0, +1, 0, -1, 0, -1, 0, +1, 0, -1, 0, -1, 0, -1, 0, -1, 0, +1, 0, -1, 0, -1, 0, -1, 0, +1, 0, +1, 0, +1, 0, -1, 0, -1, 0, +1, 0, 0, 0, +1, 0, -1, 0, +1, 0, +1, 0, +1, 0, -1, 0, +1, 0, +1, 0, -1, 0, +1, 0, +1, 0, -1, 0, +1, 0, +1, 0, +1, 0, +1, 0, -1 0, +1, 0, -1, 0, +1, 0, +1, 0, -1, 0, +1, 0, -1, 0, -1, 0, -1, 0, -1, 0, +1, 0, -1, 0, +1, 0, +1, 0, -1, 0, -1, 0, +1, 0, +1, 0, -1, 0, -1, 0, -1, 0, -1, 0, +1, 0, +1, 0, +1, 0, -1, 0, -1, 0, +1, 0, -1, 0, +1, 0, -1, 0, -1, 0, +1, 0, -1, 0, -1, 0, -1, 0, -1, 0, +1, 0, -1 0, +1}
[0237] For example, not all elements (or values) of the above 2x LTF sequence may be used. For example, among the elements (or values) of the above 2x LTF sequence, elements that do not correspond to the 52-tone RUs (1610, 1620, 1630, 1640) that are replicated four times as in FIG. 16 may be replaced with zero. In other words, ELR transmission may use the above 2X LTF sequence in 20 MHz, but only populates subcarriers corresponding to four 52-tone RUs in 20 MHz. For non-populated subcarriers, the values of the 2X UHR-LTF sequence may be replaced by zero.
[0238] For example, a power boost of 3 / 4 / 5 / 6 dB can be applied to the UHR-LTF (1940) so that the UHR-LTF (1940) has a similar power level to the L-LTF (1910).
[0239] For example, the ELR-SIG (1945) may have the following characteristics. For example, the ELR-SIG (1945) of the present specification may have two parts. Each part may be represented as ELR-SIG-1 and ELR-SIG-2. For example, the B0 bit of the ELR-SIG-1 may include the first ER / ELR-SIG information described above or the ELR Version Identifier. For example, the B0 bit of the ELR-SIG-1 may have information for identifying the ELR version, and the ELR Version Identifier included in the ELR PPDU having the technical characteristics described in the present specification may have a value of 0. For example, the position of the B0 bit may be changed.
[0240] Additionally or alternatively, the B1 bit of the ELR-SIG-1 may include a UL / DL field. For example, the bit may include information regarding whether the ELR PPDU is transmitted in UL / DL. For example, the position of the B1 bit may be changed.
[0241] Additionally or alternatively, the B2 bit of the ELR-SIG-1 may include an MCS field. For example, the bit may include information related to MCS information applied to a data field of an ELR PPDU. For example, when the bit is set to a first value (e.g., 0), the bit may indicate that BPSK with a coding rate of 1 / 2 is applied to the data field of the ELR PPDU. For example, when the bit is set to a second value (e.g., 1), the bit may indicate that QPSK with a coding rate of 1 / 2 is applied to the data field of the ELR PPDU. For example, the position of the B2 may be changed.
[0242] Additionally or alternatively, the B3 bit of the ELR-SIG-1 may include a coding (type) field. For example, the bit may include information related to coding (type) information applied to a data field of the ELR PPDU. For example, when the bit is set to a first value (e.g., 0), the bit may indicate that the BCC technique is applied to the data field of the ELR PPDU. For example, when the bit is set to a second value (e.g., 1), the bit may indicate that the LDPC technique (e.g., LDPC with a word length of 648, 1296, or 1944) is applied to the data field of the ELR PPDU.
[0243] Additionally or alternatively, bits B4 to B12 of the ELR-SIG-1 may include a length field. For example, the length field may have a length of 9 bits, and the specific bit positions may be changed. For example, the field may include information regarding the number of symbols in the data field included in the ELR PPDU.
[0244] Additionally or alternatively, the B13 bit of the ELR-SIG-1 may contain information regarding the presence of an LDPC extra (OFDM) symbol. For example, the information may include information regarding whether additional OFDM symbols are required for LDPC encoding of the PPDU.
[0245] Additionally or alternatively, bits B14 to B17 of ELR-SIG-1 may contain CRC bits, and bits B18 to B23 of ELR-SIG-1 may contain tail bits and have a value of 0.
[0246] Additionally or alternatively, bits B0 to B10 of the ELR-SIG-2 may contain information regarding the STA-ID. For example, these bits may be composed of a portion of 11 bits (e.g., 11 bits of the LSB or 11 bits of the MSB) of the AID of the STA transmitting the ELR PPDU. For example, the positions of these bits may be changed.
[0247] Additionally or alternatively, bits B1 through B13 of the ELR-SIG-2 may contain a disregard field / information. Each bit of the 3-bit field / information may be set to 1.
[0248] Additionally or alternatively, bits B14 to B17 of ELR-SIG-2 may contain CRC bits, and bits B18 to B23 of ELR-SIG-1 may contain tail bits and have a value of 0.
[0249] For example, the Data (1950) field may be called by various names such as ER / ELR-Data, Payload, etc. The Data (1950) field and ELR-SIG (1945) of this specification may be transmitted via four replicated 52-tone RUs as described below.
[0250] For example, each of ELR-SIG-1 and ELR-SIG-2 included in ELR-SIG (1945) may include information with a length of 24 bits (e.g., uncoded bits with a length of 24 bits). BCC encoding by a code rate of 1 / 2 may be applied to the 24-bit information (e.g., uncoded bits with a length of 24 bits) to generate coded bits with a length of 48 bits. BPSK modulation may be applied to the coded bits to generate 48 BPSK symbols corresponding to each of ELR-SIG-1 and ELR-SIG-2. Four pilots are added to the 48 BPSK symbols to generate data corresponding to a total of 52 subcarriers / tones, and the data is included in a 52-tone RU. These 52-tone RUs can be transmitted via a 52-tone RU replicated / repeated four times in the frequency domain (or via four replicated 52-tone RUs) according to the method described herein.
[0251] For example, information contained in Data (1950) can be mapped to a 52-tone RU based on BPSK or QPSK modulation.
[0252] An example of configuring four replicated 52-tone RUs is described below. The example of Fig. 20 described below is a more specific example of the example of Fig. 19 described above.
[0253] Figure 20 is a diagram showing four 52-tone RUs included in an ELR PPDU.
[0254] As illustrated, at least one of the ELR-SIG (1945) and / or Data (1950) fields of an ELR PPDU can be transmitted and received via four 52-tone RUs (2010, 2020, 2030, 2040). The illustrated 52-tone RUs (2010, 2020, 2030, 2040) can be included in a 20 MHz ELR PPDU.
[0255] For example, based on the technique described above, encoding of at least one of the ELR-SIG (1945) and / or Data (1950) may be performed for a 52-tone RU (2010). The 52-tone RU (2010) may be duplicated into three 52-tone RUs (2020, 2030, 2040) within a 20 MHz PPDU. In other words, the ELR-SIG and data fields may be transmitted over a 52-tone RU with four times duplication in the frequency domain across four 52-tone RUs in 20 MHz.
[0256] Additionally or alternatively, phase rotation may be performed on the four 52-tone RUs (2010, 2020, 2030, 2040).
[0257] Additionally or alternatively, a phase rotation of "-1" may be applied to the lower half of the third 52-tone RU (2030). Additionally or alternatively, a phase rotation of "-1" may be applied to the lower half of the data subcarriers of the third 52-tone RU (2030). For example, the lower half of the 52-tone RU (2030) may mean 26 subcarriers having lower indices among the 52 subcarriers of the 52-tone RU (2030) (e.g., data tones having a subcarrier index range of [43: 68]).
[0258] Additionally or alternatively, a phase rotation of "-1" may be applied to the upper half of the fourth 52-tone RU (2040). Additionally or alternatively, a phase rotation of "-1" may be applied to the data subcarriers of the upper half of the fourth 52-tone RU (2030). For example, the upper half of the 52-tone RU (2040) may mean 26 subcarriers having high indices among the 52 subcarriers of the 52-tone RU (2040) (e.g., data tones having a subcarrier index range of [96: 121]).
[0259] For example, in the example of FIG. 20, the first 52-tone RU (2010) may be located on the index range of [-121: -70]. For example, among the index range of [-121: -70], a 4-tone pilot sequence may be inserted into the indices {-116, -102, -90, -76}, and a data subcarrier may be placed on the remaining 48 tones. The 48-tone data subcarrier may include information for the ELR-SIG (1945) and / or Data (1950) fields.
[0260] For example, in the example of FIG. 20, the second 52-tone RU (2020) may be located on the index range of [-68: -17]. For example, among the index range of [-68: -17], a 4-tone pilot sequence may be inserted into the indices {-62, -48, -36, -22}, and a data subcarrier may be placed on the remaining 48 tones. The data subcarrier of the 48-tone may include information for the ELR-SIG (1945) and / or Data (1950) fields.
[0261] For example, in the example of FIG. 20, the third 52-tone RU (2030) may be located on the index range of [17: 68]. For example, among the index range of [17: 68], a pilot sequence of 4 tones may be inserted into the indices {22, 36, 48, 62}, and a data subcarrier may be placed on the remaining 48 tones. The data subcarrier of the 48 tones may include information for the ELR-SIG (1945) and / or Data (1950) fields. For example, on the third 52-tone RU (2030), the index range of [17: 42] corresponds to the lower half, and thus a phase rotation of "-1" may be applied. More specifically, a phase rotation of "-1" can be applied to the remaining 24 tones in the [17: 42] index range, excluding the pilot index {22, 36}.
[0262] For example, in the example of FIG. 20, the fourth 52-tone RU (2040) may be located on the index range of [70: 121]. For example, among the index range of [70: 121], a 4-tone pilot sequence may be inserted into the {76, 90, 102, 116} indices, and a data subcarrier may be placed on the remaining 48 tones. The 48-tone data subcarrier may include information for the ELR-SIG (1945) and / or Data (1950) fields. For example, on the fourth 52-tone RU (2040), the index range of [96: 121] corresponds to the upper half, and thus a phase rotation of "-1" may be applied. More specifically, a phase rotation of "-1" can be applied to the remaining 24 tones in the index range of [96: 121], excluding the pilot index {102, 116}.
[0263] For example, the above-mentioned index, or index range, may have a subcarrier subspacing of 78.125 kHz applied. That is, a difference of one index (or frequency index, subcarrier index, or tone index) may mean a difference of 78.125 kHz in the frequency domain.
[0264] An example of the present specification can solve problems of the prior art from various perspectives. For example, the present specification proposes an optimized location of the ELR-SIG related to ELR transmission and reception. According to an example of the present specification, the ELR-SIG is located in the ELR Preamble (1520) of FIG. 15, which is configured based on 4x (OFDM) numerology, and can be located immediately after the ELR-STF (1710) and the ELR-LTF (1720). Similar to the UHR PPDU and / or EHT PPDU, the ELR PPDU has an RL-SIG and a U-SIG, which can be used to distinguish the ELR PPDU format from other PPDU formats. However, it may be difficult to distinguish the ELR PPDU format with only the RL-SIG and / or the U-SIG. For example, due to power imbalance of UL and DL, L-SIG, RL-SIG, and / or U-SIG included in an ELR PPDU may not be correctly decoded by the receiving STA. For example, L-STF and L-LTF included in an ELR PPDU can be normally decoded and received by the receiving STA through a power boost of 3 to 6 dB. However, considering the existing PPDU transmission and reception structure, it is known that the power headroom is small for fields after the L-SIG field. Considering backward compatibility, etc., it may be desirable for the ELR PPDU to include L-SIG, RL-SIG, and / or U-SIG fields similar to those of a conventional PPDU. However, if the ELR PPDU includes L-SIG, RL-SIG, and / or U-SIG fields with a structure similar to that of a conventional PPDU, a problem may occur in which the receiving STA normally decodes only the L-STF and L-LTF and cannot normally decode the L-SIG, RL-SIG, and / or U-SIG fields.
[0265] Considering these points, it is necessary to propose additional signal fields so that a receiving STA (e.g., non-AP or AP) can normally decode an ELR PPDU even in situations where normal decoding of the L-SIG, RL-SIG, and / or U-SIG fields is not performed, and an example of such additional signal fields may be the ELR-SIG proposed in the present specification.
[0266] The ELR-SIG proposed in this specification can be replicated in the frequency domain in the same manner as the ELR Data field (e.g., the ELR Data field of FIG. 15) to overcome the power imbalance problem of UL and DL. For example, since the ELR-SIG of this specification is transmitted through a total of four 52-tone RUs in the frequency domain, normal decoding can be guaranteed at the receiving STA despite the power imbalance problem described above.
[0267] In this case, to replicate the ELR-SIG in the frequency domain in the same manner as the Data field, it is desirable to apply the same OFDM numerology to the Data field. In other words, as with the Data field, it is desirable to apply a subcarrier frequency spacing of 78.125 kHz to the ELR-SIG.
[0268] Additionally, it is desirable that the ELR-SIG be positioned immediately after the ELR-STF and ELR-LTF. Through the ELR-STF, the receiving STA can perform synchronization, automatic gain control (AGC), compensation for carrier frequency offset (CFO), etc., and through the ELR-LTF, the receiving STA can perform channel estimation. By positioning the ELR-SIG immediately after the ELR-STF and ELR-LTF, more accurate decoding by the ELR-STF and ELR-LTF can be enabled.
[0269] If the ELR-SIG (or a field performing a similar role) is located in the Legacy preamble (1510) in FIG. 15, it is difficult to transmit through a total of four 52-tone RUs in the frequency domain because it must rely on 1x OFDM numerology. In other words, if the ELR-SIG is generated based on 1x OFDM numerology, it is difficult to solve the power imbalance problem described above. Of course, a technical attempt to overcome the power imbalance problem described above can be considered by generating the ELR-SIG based on 1x OFDM numerology and repeating it in the time domain. However, if the field included in the Legacy preamble (1510) is repeated in the time domain, a problem occurs in which temporal overhead increases.
[0270] Considering these points, the ELR-SIG proposed in this specification is preferably located in the ELR Preamble (1520) of FIG. 15, which is configured based on 4x (OFDM) numerology, and is located immediately after the ELR-STF (1710) and the ELR-LTF (1720). In this case, the ELR Data (1530) may be continuous with the ELR-SIG, and the ELR-SIG preferably includes various information required for decoding the ELR Data (e.g., MCS information related to the data field and the coding type field, etc.). In addition, since it is desirable for ELR-SIG to include information necessary to interpret / decode ELR PPDU even when normal reception of L-SIG, RL-SIG, and / or U-SIG fields fails, in addition to information related to MCS and coding type, it may additionally include information such as a) 1-bit information about ELR PPDU and whether ELR PPDU is transmitted in UL / DL, b) 1-bit ELR Version Identifier, c) length field, and / or d) STA-ID. The specific configuration of ELR-SIG has already been described in detail through FIG. 19, etc.
[0271] In other words, the ELR PPDU of this specification does not perform additional repetition in the time domain for the existing L-SIG, RL-SIG, and U-SIG despite the power imbalance problem. Accordingly, one L-SIG, one RL-SIG, and one U-SIG can be configured in one ELR PPDU of this specification based on the existing 1x OFDM numerology. However, the ELR PPDU of this specification proposes a new structure in which it is transmitted a total of four times in the frequency domain immediately after the ELR-STF (1710) and ELR-LTF (1720) configured based on 4x (OFDM) numerology so that the ELR-SIG can be accurately decoded at the receiving STA while solving the power imbalance problem. The ELR-SIG may include once more some of the information that was included in the existing L-SIG, RL-SIG, and / or U-SIG fields. This is because normal decoding / interpretation of the ELR PPDU is possible through the ELR-SIG field even if the L-SIG, RL-SIG, and / or U-SIG fields are not normally decoded by the receiving STA.
[0272] Figure 21 is an example of a procedure flowchart related to the present specification. The procedure illustrated in Figure 21 may be performed by a non-AP STA, a non-AP MLD, an AP (Access Point), or an AP MLD (AP Multi-link Device).
[0273] As illustrated in step S2110, an STA (e.g., non-AP or AP) may generate (or configure, construct) an LR / ELR PPDU. For example, the ELR PPDU of step S2110 may be an ELR PPDU related to FIGS. 15 to 20.
[0274] For example, the ELR PPDU may include an L-SIG (legacy signal) field, an RL-SIG (repeated signal field) which is a repetition of the L-SIG field, and a U-SIG (universal signal) field which includes information necessary for interpreting the ELR PPDU. The L-SIG field, the RL-SIG field, and the U-SIG field may be generated based on a first subcarrier frequency spacing (or 1x OFDM numerology).
[0275] For example, the ELR PPDU may further include a Short Training Field (STF), a Long Training Field (LTF), an ELR Signal (ELR-SIG) field, and a data field. The STF, the LTF, the ELR-SIG field, and the data field may be generated based on a second subcarrier frequency spacing (or 4x OFDM numerology).
[0276] For example, the STF may be called by various names such as ELR / UHR-STF (e.g., UHR ELR STF). For example, the LTF may be called by various names such as ELR / UHR-LTF (e.g., UHR ELR LTF). The data field may be called by various names such as ELR data field, UHR data field, UHR-ELR data field, etc.
[0277] For example, the ELR-SIG field can be transmitted and received through four 52-tone resource units (RUs) duplicated in the frequency domain in units of 52-tone RUs.
[0278] For example, the above ELR PPDU may have a bandwidth of 20 MHz.
[0279] For example, the RL-SIG field may be continuous with the L-SIG field, and the U-SIG field may be continuous with the RL-SIG field. In other words, the L-SIG field may be transmitted and received through a first symbol, the RL-SIG field may be transmitted and received through a second symbol, and the U-SIG field may be transmitted and received through third and fourth symbols, and the first to fourth symbols may be continuous with each other.
[0280] For example, the LTF may be continuous to the STF, and the ELR-SIG field may be continuous to the LTF.
[0281] For example, the first subcarrier frequency spacing (e.g., 312.5 kHz) may be four times the second subcarrier frequency spacing (e.g., 78.125 kHz).
[0282] As described above, the U-SIG may include two parts (e.g., U-SIG1 and U-SIG2). For example, the first part (U-SIG1) of the two parts may include a first field related to PPDU Type and Compression Mode for identifying that the PPDU is an ELR PPDU, and the first field may have a value of three (3). For example, the second symbol of the two symbols may include a validate field for identifying that the PPDU is an ELR PPDU, the length of the validate field may be 3 bits, and the validate field may have a value of seven (7).
[0283] For example, the U-SIG field may further include various bits (e.g., various information / fields defined in U-SIG1 or U-SIG2).
[0284] For example, the ELR PPDU associated with step S2110 may further include a long training field (LTF) signal. Additionally or alternatively, the LTF signal may be based on a 2x LTF sequence as described herein.
[0285] For example, the ELR-SIG (or UHR-SIG) may include information about an MCS (modulation and coding scheme) index applied to the data field (e.g., ELR Data field). For example, the MCS applied to the data field may be related to either Binary Phase-Shift Keying (BPSK) or Quadrature Phase Shift Keying (QPSK). For example, the ER-SIG field may further include second information about a coding type applied to the data field, and the second information may have a length of 1 bit. For example, the ER-SIG field may further include third information about whether an additional OFDM (Orthogonal Frequency-Division Multiplexing) symbol for LDPC (Low-Density Parity-Check) coding of the PPDU is required, and the third information may have a length of 1 bit.
[0286] For example, the data field (and / or the ER / ELR-SIG field) may be transmitted via a plurality of 52-tone resource units (RUs) that are duplicated in the frequency domain. In other words, the data field (and / or the ER / ELR-SIG field) may be transmitted via a plurality of 52-tone RUs (e.g., four 52-tone RUs) that are duplicated in the frequency domain in units of 52-tone resource units.
[0287] For example, the data field and / or the ER / ELR-SIG field may be transmitted and received based on an RU having a structure as in FIG. 20 (e.g., a duplicated / repeated 52-tone RU). For example, the data field and / or the ER / ELR-SIG field may be transmitted based on four 52-tone RUs that are duplicated in the frequency domain (e.g., in units of 52-tone RUs). In this case, the four 52-tone RUs may be sequentially positioned in the frequency domain, from the first 52-tone RU to the fourth 52-tone RU, and a phase rotation of minus one (-1) may be applied to a tone in the lower half of the third 52-tone RU, and a phase rotation of minus one (-1) may be applied to a tone in the upper half of the fourth 52-tone RU. In this case, a phase rotation of one (1) may be applied to the first 52-tone RU and the second 52-tone RU, a phase rotation of one (1) may be applied to the upper half tone of the third 52-tone RU, and a phase rotation of one (1) may be applied to the lower half tone of the fourth 52-tone RU.
[0288] As illustrated in S2120 of FIG. 21, an STA (e.g., non-AP or AP) may transmit a PPDU. For example, the PPDU may be transmitted via a single spatial stream. For example, the RU through which the PPDU is transmitted may be based on a 52-tone RU that is duplicated / repeated as described above.
[0289] Figure 22 is an example of a procedure flowchart related to this specification. The procedure illustrated in Figure 22 may be performed by a non-AP STA, a non-AP MLD, an AP (Access Point), or an AP MLD (AP Multi-link Device).
[0290] As illustrated in S2210, an STA (e.g., non-AP or AP) can receive an ELR PPDU. For example, the ELR PPDU of step S2210 may be identical to the ELR PPDU of step S2110. Accordingly, technical features applicable to step S2110 may also be applied to step S2210. In other words, an STA can receive an ELR PPDU related to step S2110 through step S2210. Accordingly, any redundant description of step S2210 is omitted.
[0291] As illustrated in S2220, the STA (e.g., non-AP or AP) can decode the ELR PPDU received through step S2110. For example, the STA can decode the data field (e.g., ELR Data field) of the PPDU based on the information of the U-SIG field included in the PPDU and / or the information of the ELR-SIG field. For example, the STA of the present specification can decode the data field (e.g., ELR Data field) of the PPDU based on the information of the ELR-SIG field even if it fails to normally decode the U-SIG field.
[0292] The technical features of the present disclosure may be implemented by various devices. The devices of the present disclosure may be the devices described in FIG. 1 / FIG. 14. The devices of the present disclosure may include at least one processor; and at least one computer memory operably connectable to the at least one processor, the computer memory storing instructions for performing operations based on execution by the at least one processor.
[0293] For example, the processor may be a processor described in FIG. 1 and / or FIG. 14. That is, as described above, the processor of the present specification 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). The processor may include not only computers having various architectures such as single / multiprocessor architecture, sequential (Von Neumann) / parallel architecture, but also specialized circuits such as FPGAs, ASICs, signal processing devices, and other devices. For example, the processor of the present specification may be a SNAPDRAGON® series processor manufactured by Qualcomm®, an EXYNOS® series processor manufactured by Samsung®, an A series processor manufactured by Apple®, a HELIO® series processor manufactured by MediaTek®, an ATOM® series processor manufactured by INTEL®, or a processor that enhances the same.
[0294] For example, the instructions may refer to computer program instructions executed by the at least one processor. The (computer program) instructions provide logic and / or routines that enable the technical features of the present specification to be performed by the processor. The at least one processor can load and execute a computer program by reading the at least one memory.
[0295] The computer program(s) defined by the above instructions may be delivered to the device (e.g., STA) of the present specification via an appropriate delivery mechanism. The delivery mechanism may be, for example, a computer-readable storage medium, a computer program product, a memory device, a recording medium such as a CD-ROM or DVD, or a product tangibly embodying the computer program. The delivery mechanism may be a signal configured to reliably transmit the computer program via a wireless or electrical connection.
[0296] The above (computer program) instructions may include software or firmware for a programmable processor (e.g., programmable content of a hardware device whether instructions for a processor, or configuration settings for a fixed-function device, gate array or programmable logic device, etc.).
[0297] For example, the memory may be the memory described in FIG. 1 and / or FIG. 14. That is, as described above, the memory of the present specification may store control information related to the operation of the STA of the present specification or information about signals transmitted and received by the STA (e.g., PPDU including management / control / data frames).
[0298] The technical features of this specification may be implemented in at least one computer-readable recording medium (CRM). The CRM includes instructions that are executed by at least one processor as described above. The instructions stored in the CRM may be computer program instructions as described above.
[0299] The device of the present disclosure may further include a transceiver. The transceiver may be operably connectable to the memory / processor, etc. The transceiver may be the transceiver illustrated in FIG. 1 and / or FIG. 14.
[0300] 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).
[0301] 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.
[0302] 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.
[0303] 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.
[0304] 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.
[0305] 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.
[0306] Machine learning can be classified into supervised learning, unsupervised learning, and reinforcement learning depending on the learning method.
[0307] 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 certain environment is taught to select actions or action sequences that maximize cumulative rewards in each state.
[0308] 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.
[0309] Additionally, the above-described technical features can be applied to wireless communication of robots.
[0310] 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.
[0311] 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.
[0312] Additionally, the above-described technical features can be applied to devices that support extended reality.
[0313] 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.
[0314] 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.
[0315] 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.
Claims
1. A step for generating an ELR (Enhanced Long Range) PPDU (physical protocol data unit); and Step of transmitting the above ELR PPDU Including, but not limited to, The ELR PPDU includes an L-SIG (legacy signal) field, an RL-SIG (repeated signal field) which is a repetition of the L-SIG field, and a U-SIG (Universal signal) field which includes information necessary for interpreting the ELR PPDU. The L-SIG field, the RL-SIG field, and the U-SIG field are generated based on the first subcarrier frequency spacing, The above ELR PPDU further includes an STF (Short Training Field), an LTF (Long Training Field), an ELR-SIG (ELR Signal) field, and a data field. The STF, the LTF, the ELR-SIG field, and the data field are generated based on the second subcarrier frequency spacing, The above ELR-SIG field is transmitted through four 52-tone RUs (resource units) duplicated in the frequency domain in units of 52-tone RUs. method.
2. In the first paragraph, the ELR PPDU has a bandwidth of 20 MHz. method.
3. In the first paragraph, the RL-SIG field is continuous to the L-SIG field, and the U-SIG field is continuous to the RL-SIG field. method.
4. In the first paragraph, the LTF is continuous to the STF, and the ELR-SIG field is continuous to the LTF. method.
5. In the first paragraph, the first subcarrier frequency spacing is four times the second subcarrier frequency spacing. method.
6. In paragraph 1, the ELR-SIG field includes additional information for interpreting the ELR PPDU, The above additional information includes information related to the MCS (Modulation and Coding Scheme) of the data field. method.
7. In the first paragraph, the data field is transmitted through four 52-tone RUs (resource units) duplicated in the frequency domain in units of 52-tone RUs. method.
8. In the first paragraph, the ELR PPDU is transmitted based on one spatial stream. method.
9. At least one processor; and At least one computer memory operable to said at least one processor, said memory storing instructions for performing operations based on being executed by said at least one processor, The instructions of at least one computer memory are: Generate an ELR (Enhanced Long Range) PPDU (physical protocol data unit), wherein the ELR PPDU includes an L-SIG (legacy signal) field, an RL-SIG (repeated signal field) which is a repetition of the L-SIG field, and a U-SIG (Universal signal) field which includes information necessary for interpreting the ELR PPDU. The L-SIG field, the RL-SIG field, and the U-SIG field are generated based on the first subcarrier frequency spacing, The above ELR PPDU further includes an STF (Short Training Field), an LTF (Long Training Field), an ELR-SIG (ELR Signal) field, and a data field. The STF, the LTF, the ELR-SIG field, and the data field are generated based on the second subcarrier frequency spacing, The above ELR-SIG field is transmitted in the frequency domain in units of 52-tone RU (resource unit) through four duplicated 52-tone RUs. Including STA (station) performing the action.
10. In the 9th paragraph, the command of at least one computer memory performs an operation related to any one of the 1st to 8th paragraphs. STA.
11. Receive ELR (Enhanced Long Range) PPDU (physical protocol data unit) by STA (station), The ELR PPDU includes an L-SIG (legacy signal) field, an RL-SIG (repeated signal field) which is a repetition of the L-SIG field, and a U-SIG (Universal signal) field which includes information necessary for interpreting the ELR PPDU. The L-SIG field, the RL-SIG field, and the U-SIG field are generated based on the first subcarrier frequency spacing, The above ELR PPDU further includes an STF (Short Training Field), an LTF (Long Training Field), an ELR-SIG (ELR Signal) field, and a data field. The STF, the LTF, the ELR-SIG field, and the data field are generated based on the second subcarrier frequency spacing, The above ELR-SIG field is received through four 52-tone RUs (resource units) duplicated in the frequency domain in units of 52-tone RUs; and A step of interpreting the ELR PPDU based on the U-SIG field and / or the ELR-SIG field. How to include.
12. In the 11th paragraph, the STA performs an operation related to any one of the 1st to 8th paragraphs. method.
13. At least one processor; and At least one computer memory operable to said at least one processor, said memory storing instructions for performing operations based on being executed by said at least one processor, The instructions of at least one computer memory are: By STA (station), ELR (Enhanced Long Range) PPDU (physical protocol data unit) is received, The ELR PPDU includes an L-SIG (legacy signal) field, an RL-SIG (repeated signal field) which is a repetition of the L-SIG field, and a U-SIG (Universal signal) field which includes information necessary for interpreting the ELR PPDU. The L-SIG field, the RL-SIG field, and the U-SIG field are generated based on the first subcarrier frequency spacing, The above ELR PPDU further includes an STF (Short Training Field), an LTF (Long Training Field), an ELR-SIG (ELR Signal) field, and a data field. The STF, the LTF, the ELR-SIG field, and the data field are generated based on the second subcarrier frequency spacing, The above ELR-SIG field is received through four 52-tone RUs (resource units) duplicated in the frequency domain in units of 52-tone RUs; and A step of interpreting the ELR PPDU based on the U-SIG field and / or the ELR-SIG field. Including STA (station) performing the action.
14. In the 13th paragraph, the STA performs an operation related to any one of the 1st to 8th paragraphs. method.
15. In a wireless local area network (WLAN) system, at least one computer-readable recording medium including instructions based on being executed by at least one processor, Generate an ELR (Enhanced Long Range) PPDU (physical protocol data unit), wherein the ELR PPDU includes an L-SIG (legacy signal) field, an RL-SIG (repeated signal field) which is a repetition of the L-SIG field, and a U-SIG (Universal signal) field which includes information necessary for interpreting the ELR PPDU. The L-SIG field, the RL-SIG field, and the U-SIG field are generated based on the first subcarrier frequency spacing, The above ELR PPDU further includes an STF (Short Training Field), an LTF (Long Training Field), an ELR-SIG (ELR Signal) field, and a data field. The STF, the LTF, the ELR-SIG field, and the data field are generated based on the second subcarrier frequency spacing, The above ELR-SIG field is transmitted in a step of 52-tone RU (resource unit) units through four 52-tone RUs duplicated in the frequency domain; and Step of transmitting the above ELR PPDU Performing an operation that includes Recording medium.
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