Method and apparatus for ppdu transmission and reception in wireless lan system

Abstract

Methods and apparatuses for PPDU transmission and reception in a wireless LAN system are disclosed. A method according to embodiments of the present disclosure can include the steps of generating, by a first STA, a PPDU, wherein one or more data bits are mapped to each of data subcarriers for data transmission in the PPDU based on an MCS; and transmitting, by the first STA, the PPDU to a second STA.

Description

Technical Field

[0001] This disclosure relates to a method and apparatus for transmitting and receiving Physical Protocol Data Units (PPDUs) in a Wireless Local Area Network (WLAN) system. Background Technology

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

[0003] To provide a more advanced wireless communication environment, improved techniques for Extremely High Throughput (EHT) are being discussed. For example, techniques for MIMO and multiple access point (AP) coordination that support increased bandwidth, efficient use of multiple frequency bands, and increased spatial flow are being investigated. Specifically, various techniques are being explored to support low-latency or real-time services. Furthermore, new technologies to support Ultra-High Reliability (UHR), including improvements or extensions to EHT techniques, are being discussed. Summary of the Invention

[0004] Technical issues

[0005] The technical objective of this disclosure is to provide methods and apparatus for transmitting and receiving PPDUs using spatial modulation schemes.

[0006] The technical objectives to be achieved by this disclosure are not limited to those described above, and other technical objectives not described herein will be clearly understood by those skilled in the art through the following description.

[0007] Technical solution

[0008] A method according to one aspect of this disclosure may include the following steps: generating a PPDU (Physical Protocol Data Unit) by a first station (STA), wherein one or more data bits are mapped to each of the data subcarriers within the PPDU for data transmission based on a modulation and coding scheme (MCS); and transmitting the PPDU from the first STA to a second STA, wherein an additional bit of data is transmitted in each of the data subcarriers based on spatial modulation using a combination of specific antennas.

[0009] The method according to an additional aspect of this disclosure may include the following steps: receiving a PPDU (Physical Protocol Data Unit) from a first STA by a second station (STA); and processing the PPDU. One or more data bits are mapped to each of the data subcarriers within the PPDU for data transmission based on a modulation and coding scheme (MCS), and an additional bit of data is transmitted in each of the data subcarriers based on spatial modulation using a combination of specific antennas.

[0010] Technical effect

[0011] According to embodiments of this disclosure, additional data bits are further transmitted and received in each subcarrier based on spatial modulation using antenna combinations, thereby increasing data transmission throughput and improving wireless communication efficiency.

[0012] The effects achievable by this disclosure are not limited to those described above, and those skilled in the art can clearly understand other effects not described herein through the following description. Attached Figure Description

[0013] The accompanying drawings, which are included as part of the detailed description of this disclosure, provide embodiments of the disclosure and, together with the detailed description, describe the technical features of the disclosure.

[0014] Figure 1 A configuration block diagram of a wireless communication device according to an embodiment of the present disclosure is illustrated.

[0015] Figure 2 This is a diagram illustrating an exemplary structure of a WLAN system to which this disclosure can be applied.

[0016] Figure 3 This is a diagram used to illustrate the link establishment process that can be applied to this disclosure.

[0017] Figure 4 This is a diagram used to illustrate the backoff processing that can be applied to this disclosure.

[0018] Figure 5 This is a diagram illustrating the CSMA / CA-based frame transmission operation that can be applied to this disclosure.

[0019] Figure 6 This is a diagram illustrating an example of a frame structure that can be used in a WLAN system to which this disclosure may be applied.

[0020] Figure 7 This is a diagram illustrating an example of a PPDU as defined in the IEEE 802.11 standard of this disclosure.

[0021] Figure 8This is a diagram illustrating an exemplary arrangement of resource units (RUs) used in a 20 MHz frequency band.

[0022] Figure 9 This is a diagram illustrating an exemplary arrangement of resource units (RUs) used in a 40 MHz frequency band.

[0023] Figure 10 This is a diagram illustrating an exemplary arrangement of resource units (RUs) used in the 80 MHz band.

[0024] Figure 11 A transmitter block diagram according to one embodiment of the present disclosure is illustrated.

[0025] Figure 12 An example of a PPDU format according to one embodiment of the present disclosure is shown.

[0026] Figure 13 A receiver block diagram according to one embodiment of the present disclosure is illustrated.

[0027] Figure 14 The operation of a transmitting apparatus for a PPDU transmitting and receiving method according to one embodiment of the present disclosure is illustrated.

[0028] Figure 15 The operation of a receiving apparatus for a PPDU transmission and reception method according to one embodiment of the present disclosure is illustrated. Detailed Implementation

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

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

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

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

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

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

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

[0036] Figure 1 A block diagram illustrating a wireless communication device according to an embodiment of the present disclosure is shown.

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

[0038] Figure 1 The devices 100 and 200 illustrated herein may be referred to as stations (STAs). For example, Figure 1 The devices 100 and 200 illustrated herein may be referred to by various terms such as transmitting device, receiving device, transmitting STA, and receiving STA. For example, STA 110 and 200 may perform an access point (AP) role or a non-AP role. That is, in this disclosure, STA 110 and 200 may perform AP and / or non-AP functions. When STA 110 and 200 perform AP functions, they may simply be referred to as APs, and when STA 110 and 200 perform non-AP functions, they may simply be referred to as STAs. Alternatively, in this disclosure, AP may also be referred to as AP STA.

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

[0040] In addition to wireless LAN technology, the first device 100 and the second device 200 can also support various communication standards (e.g., 3GPP LTE series, 5G NR series standards, etc.). Furthermore, the devices disclosed herein can be implemented in various devices such as mobile phones, vehicles, personal computers, augmented reality (AR) devices, and virtual reality (VR) devices. Additionally, the STA of this specification can support various communication services such as voice calls, video calls, data communication, autonomous driving, machine-type communication (MTC), machine-to-machine (M2M), device-to-device (D2D), and IoT (Internet of Things).

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

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

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

[0044] One or more processors 102, 202 may be referred to as controllers, microcontrollers, microprocessors, or microcomputers. One or more processors 102, 202 may be implemented by hardware, firmware, software, or a combination thereof. For example, one or more ASICs (Application-Specific Integrated Circuits), one or more DSPs (Digital Signal Processors), one or more DSPDs (Digital Signal Processing Devices), one or more PLDs (Programmable Logic Devices), or one or more FPGAs (Field-Programmable Gate Arrays) may be included in one or more processors 102, 202. The descriptions, functions, processes, suggestions, methods, and / or operation flowcharts included in this disclosure may be implemented using firmware or software, and the firmware or software may be implemented to include modules, processes, functions, etc. Firmware or software configured to execute the descriptions, functions, processes, suggestions, methods, and / or operation flowcharts included in this disclosure may be included in one or more processors 102, 202, or may be stored in one or more memories 104, 204 and driven by one or more processors 102, 202. The descriptions, functions, processes, suggestions, methods and / or operation flowcharts included in this disclosure may be implemented using firmware or software in the form of code, instructions and / or instruction sets.

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

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

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

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

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

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

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

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

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

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

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

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

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

[0058] In addition to the DS structure described above, Extended Service Sets (ESS) can also be configured to provide wide coverage.

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

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

[0061] Figure 3 This is a diagram illustrating the link establishment process that can be applied to this disclosure.

[0062] In order for a STA to establish a link with the network and send / receive data, it first discovers the network, performs authentication, establishes an association, and performs authentication processing for security. The link establishment process can also be called session initiation processing or session establishment processing. Furthermore, the discovery, authentication, association, and security establishment processes of the link establishment process can be collectively referred to as association processing.

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

[0064] Scanning schemes include active scanning and passive scanning. Figure 3An exemplary network discovery operation including active scanning processing is illustrated. In active scanning, the STA performing the scan sends a probe request frame to discover which APs are present around it as the channel moves and awaits a response. The responder sends a probe response frame as a response to the probe request frame to the STA that sent the probe request frame. Here, the responder may be the STA that last sent a beacon frame in the BSS of the channel being scanned. In the BSS, the AP becomes the responder because it sends a beacon frame, and in the IBSS, the STAs in the IBSS rotate to send beacon frames, so the responder is not constant. For example, an STA that sends a probe request frame on channel 1 and receives a probe response frame on channel 1 may store the BSS-related information included in the received probe response frame and may move to the next channel (e.g., channel 2) and perform a scan in the same manner (i.e., sending and receiving probe requests / responses on channel 2).

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

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

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

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

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

[0070] After the STA is successfully authenticated, the association process can be performed in step S330. The association process includes the following steps: the STA sends an association request frame to the AP, and in response, the AP sends an association response frame to the STA.

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

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

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

[0074] Figure 4 This is a diagram illustrating the fallback process that can be applied to this disclosure.

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

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

[0077] Reference Figure 4 This section describes the operation based on a random backoff period. When an occupied / busy medium becomes idle, multiple STAs can attempt to transmit data (or frames). As a method to minimize collisions, each STA can individually select a random backoff count and attempt to transmit after waiting for the corresponding time slot. The random backoff count has a pseudo-random integer value and can be determined as one of the values ​​ranging from 0 to CW. Here, CW is the contention window parameter value. The CW parameter is assigned an initial value of CWmin, but can take a value twice as large as in the event of transmission failure (e.g., when no ACK is received for the transmitted frame). When the CW parameter value reaches CWmax, data transmission can be attempted while maintaining the CWmax value until successful data transmission, and when successful, the CWmin value is reset. The values ​​of CW, CWmin, and CWmax are preferably set to 2.n -1 (n=0, 1, 2, ...).

[0078] When random backoff processing begins, the STA continuously monitors the medium during the backoff time slot countdown based on the determined backoff count value. When monitoring the medium for occupancy, it stops the countdown and waits, and restarts the remainder of the countdown when the medium becomes idle.

[0079] exist Figure 4 In the example, when the packet to be sent arrives at STA 3's MAC, STA 3 can send the frame immediately after confirming that the medium has been idle for up to DIFS. The remaining STAs monitor and wait for the medium to be occupied / busy. Meanwhile, the data to be sent can also occur in each of STA 1, STA 2, and STA 5, and when the medium is detected as idle, each STA waits for up to DIFS, and then performs a countdown for the backoff slot based on a random backoff count value chosen by each STA. Assume STA 2 chooses the minimum backoff count value, and STA 1 chooses the maximum backoff count value. That is, the example illustrates the case where STA 5's remaining backoff time is shorter than STA 1's remaining backoff time when STA 2 completes its backoff count and begins frame transmission. STA 1 and STA 5 temporarily stop the countdown and wait while STA 2 occupies the medium. When STA 2's occupancy ends and the medium becomes idle again, STA 1 and STA 5 wait for DIFS and restart the stopped backoff count. In other words, frame transmission can begin after a countdown for the remaining backoff slot based on the remaining backoff time. Since STA5 has a shorter remaining backoff time than STA1, STA5 begins frame transmission. Data to be transmitted can also occur in STA4 while STA2 is occupying the medium. From STA4's perspective, when the medium becomes idle, STA4 can wait for DIFS, then execute a countdown based on a random backoff count value selected by STA4, and begin transmitting frames. Figure 4 The example illustrates a scenario where the remaining backoff time of STA5 accidentally conflicts with the random backoff count value of STA4. In this case, a collision may occur between STA4 and STA5. When a collision occurs, neither STA4 nor STA5 receives an ACK, so data transmission fails. In this situation, STA4 and STA5 can double the CW value, select a random backoff count value, and begin a countdown. While the medium is occupied due to the transmissions of STA4 and STA5, STA1 waits; when the medium becomes idle, STA1 waits for DIFS, and then begins frame transmission after the remaining backoff time has elapsed.

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

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

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

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

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

[0085] To reduce the likelihood of transmission conflicts among multiple STAs in CSMA / CA-based frame transmission operations, a mechanism using RTS / CTS frames can be applied. Figure 5 In the example, when STA1 is transmitting, as a result of carrier sensing by STA3, it can be determined that the medium is in an idle state. That is, STA1 can correspond to a hidden node with respect to STA3. Alternatively, in Figure 5 In the example, it can be determined that while STA2 is transmitting, the carrier sensing result medium of STA3 is in an idle state. That is, STA2 can correspond to a hidden node with respect to STA3. By exchanging RTS / CTS frames before performing data transmission and reception between STA1 and STA2, STAs outside the transmission range of either STA1 or STA2, or STAs outside the carrier sensing range of transmissions from STA1 or STA3, can avoid attempting to occupy the channel during data transmission and reception between STA1 and STA2.

[0086] Specifically, STA1 can determine whether a channel is in use through carrier sensing. Regarding physical carrier sensing, STA1 can determine the channel occupancy / idle status based on the energy level or signal correlation detected in the channel. Alternatively, regarding virtual carrier sensing, STA1 can use a Network Allocation Vector (NAV) timer to determine the channel occupancy status.

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

[0102] Compared to the basic PPDU format, the HT PPDU format (IEEE 802.11n) additionally includes the HT-SIG, HT-STF, and HT-LFT fields. Figure 7 The HT PPDU format shown in (b) can be referred to as the HT hybrid format. Furthermore, an HT green format PPDU can be defined, and this corresponds to a format consisting of HT-GF-STF, HT-LTF1, HT-SIG, one or more HT-LTFs and data fields, excluding L-STF, L-LTF, and L-SIG (not shown).

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

[0104] Compared to the basic PPDU format, examples of the HE PPDU format (IEEE 802.11ax) additionally include repeated L-SIG (RL-SIG), HE-SIG-A, HE-SIG-B, HE-STF, HE-LTF, and Packet Extension (PE) fields (such as...). Figure 7 (as shown in (d)). Some fields can be excluded, or their lengths can vary depending on the detailed examples of the HE PPDU format. For example, the HE-SIG-B field is included in the HE PPDU format for multi-user (MU), but not in the HE PPDU format for single-user (SU). Furthermore, the HE-Trigger-Based (TB) PPDU format does not include HE-SIG-B, and the length of the HE-STF field can vary up to 8 μs. The Extended Range (HE ER) SU PPDU format does not include the HE-SIG-B field, and the length of the HE-SIG-A field can vary up to 16 μs. For example, RL-SIG can be configured to be the same as L-SIG. Based on the presence of RL-SIG, the receiving STA can determine whether the received PPDU is an HE PPDU or an EHT PPDU, which will be described later.

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

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

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

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

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

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

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

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

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

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

[0115] For example, the version-independent bits of U-SIG may include a 3-bit Physical Layer Version Identifier (PHY Version Identifier), which can indicate the PHY version (e.g., EHT, UHR, etc.) of the transmitted / received PPDU. The version-independent bits of U-SIG may include a 1-bit UL / DL Flag field. The first value of the 1-bit UL / DL Flag field is related to UL communication, and the second value is related to DL communication. The version-independent bits of U-SIG may include information about the length of the Transmission Opportunity (TXOP) and information about the BSS color ID.

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

[0117] Information required for PPDU transmission and reception can be included in the U-SIG. For example, the U-SIG may also include information about bandwidth, information about the MCS technique applied to non-traditional SIGs (e.g., EHT-SIG or UHR-SIG), information indicating whether DCM (dual-carrier modulation) techniques (e.g., techniques used to achieve effects similar to frequency diversity by reusing the same signal on two subcarriers) are applied to non-traditional SIGs, information about the number of symbols used for non-traditional SIGs, and information about whether non-traditional SIGs are generated across the entire frequency band.

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

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

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

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

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

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

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

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

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

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

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

[0129] Figure 7 The names of each field in the PPDU format are exemplary, and the scope of this disclosure is not limited to these names. Furthermore, the examples in this disclosure can be applied to… Figure 7 The PPDU format shown and based on Figure 7 A new PPDU format that excludes some fields and / or adds some fields, based on the PPDU format.

[0130] Resource Units (RUs) and Resource Allocation

[0131] Figures 8 to 10 This is a diagram illustrating an example of a resource unit for a wireless LAN system to which this disclosure can be applied.

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

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

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

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

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

[0137] exist Figure 8 The examples illustrate various sizes of RUs, namely 26-RU, 52-RU, 106-RU, 242-RU, etc., but the specific size of these RUs can be reduced or expanded. Therefore, the specific size of each RU in this disclosure (i.e., the number of corresponding tones) is exemplary and not limiting. Furthermore, within a given bandwidth in this disclosure (e.g., 20 MHz, 40 MHz, 80 MHz, 160 MHz, 320 MHz, ...), the number of RUs can vary depending on the RU size. The following description... Figure 9 and / or Figure 10 Examples and Figure 8 The example is the same, because the size and / or number of RUs can be changed.

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

[0139] For example, when using RUs of various sizes Figure 8 In the example, Figure 9Examples 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 guard bands in the leftmost band of the 40MHz band, and 11 tones can be used as guard bands in the rightmost band of the 40MHz band.

[0140] Additionally, as shown in the figure, the 484-RU can be used for a single user.

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

[0142] For example, using RUs of various sizes Figure 8 and Figure 9 In the example, Figure 10 Examples can also use 26-RU, 52-RU, 106-RU, 242-RU, 484-RU, 996-RU, etc. Furthermore, in the case of an 80 MHz PPDU, the RU layout of the HE PPDU and EHT PPDU can be different, and... Figure 10 The example shows an example of a RU layout for an 80 MHz EHT PPDU. Figure 10 In the example, 12 tones are used as guard bands in the leftmost band of the 80 MHz band, and 11 tones are used as guard bands in the rightmost band of the 80 MHz band, which is the same for both HE PPDU and EHT PPDU. Unlike the HE PPDU, which inserts 7 DC tones in the DC band and has one 26-RU corresponding to 13 tones on each of the left and right sides of the DC band, the EHT PPDU inserts 23 DC tones in the DC band and has one 26-RU on each of the left and right sides of the DC band. Unlike the HE PPDU, which has one empty subcarrier between the 242-RUs excluding the center band, the EHT PPDU has five empty subcarriers. In the HE PPDU, a 484-RU does not contain any empty subcarriers, while in the EHT PPDU, a 484-RU contains five empty subcarriers.

[0143] Furthermore, as shown in the figure, when used for a single user, the 996-RU can be used, in which case the insertion of 5 DC tones is common to both the HE PPDU and EHT PPDU.

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

[0145] Here, an MRU corresponds to a group of subcarriers (or tones) composed of multiple RUs, and the multiple RUs constituting an MRU can be RUs of the same size or RUs of different sizes. For example, a single MRU can be defined as 52+26 tones, 106+26 tones, 484+242 tones, 996+484 tones, 996+484+242 tones, 2×996+484 tones, 3×996 tones, or 3×996+484 tones. The multiple RUs constituting an MRU can correspond to small-sized RUs (e.g., 26, 52, 106) or large-sized RUs (e.g., 242, 484, 996, etc.). That is, a single MRU including both small-sized and large-sized RUs may not be configured / defined. Furthermore, the multiple RUs constituting a single MRU may or may not be contiguous in the frequency domain.

[0146] If the 80 MHz subblock includes RUs with fewer than 996 tones, or if the position of the 80 MHz subblock is punched, then the 80 MHz subblock can use an RU placement other than the 996-tone RUs.

[0147] Depending on the bandwidth of each PPDU, the location of the RU can be fixed as defined in Tables 1 to 5 below.

[0148] Table 1 illustrates the index of RUs in a 20 MHz PPDU, as well as the data and pilot subcarrier indexes (range) for each RU.

[0149] [Table 1]

[0150] Table 2 illustrates the index of RUs within a 40 MHz PPDU, as well as the data and pilot subcarrier indexes (range) for each RU.

[0151] [Table 2]

[0152] Table 3 illustrates the index of RUs within an 80 MHz PPDU, as well as the data and pilot subcarrier indexes (range) for each RU.

[0153] [Table 3]

[0154] Table 4 illustrates the index of RUs within a 160 MHz PPDU, as well as the data and pilot subcarrier indexes (range) for each RU.

[0155] [Table 4]

[0156] Table 5 illustrates the index of RUs within a 320 MHz PPDU, as well as the data and pilot subcarrier indexes (range) for each RU.

[0157] [Table 5]

[0158] In Table 1, RU5 corresponds to the middle 26-tone RU.

[0159] Referring to Tables 1 through 5, subcarrier index 0 corresponds to the DC tone. A negative subcarrier index corresponds to a subcarrier with a frequency lower than the DC tone. A positive subcarrier index corresponds to a subcarrier with a frequency higher than the DC tone. A DC subcarrier can refer to a subcarrier with zero energy, including both the DC tone and subcarrier indices adjacent to subcarrier index 0 (i.e., the DC tone). A guard subcarrier can refer to a subcarrier located at the edge of an OFDM symbol in the frequency domain and having zero energy. Empty subcarriers are located near the DC or edge tones to prevent transmission center frequency leakage, receiver DC offset, and interference from adjacent RUs or MRUs, and have zero energy.

[0160] Reference Figures 8 to 10 And Tables 1 to 5 show that for each RU, the RU index can be assigned in order from low frequency to high frequency.

[0161] A PPDU in the 160 MHz or higher range can consist of multiple 80 MHz frequency subblocks. The tone scheme and RU allocation for each 80 MHz frequency subblock can be the same as those for the 80 MHz PPDU. If the 80 MHz frequency subblock of a 160 MHz or 320 MHz PPDU is not punched and the entire 80 MHz frequency subblock is used as an RU or part of an RU / MRU, then the 80 MHz frequency subblock can be used. Figure 9The 996-tone RU is shown. If the 80 MHz frequency subblock includes RUs with fewer than 996 tones or a portion of the 80 MHz frequency subblock is punched, the 80 MHz frequency subblock can use tone schemes and RU allocations other than 996-tone RUs, such as... Figure 9 As shown.

[0162] Multiple RUs (MRUs) can be assigned to a STA. The subcarrier index of an MRU can be formed by the indices of the corresponding RUs that make up the MRU.

[0163] The RU disclosed herein can be used for uplink (UL) and / or downlink (DL) communication. For example, when performing trigger-based UL-MU communication, the STA that sends the trigger (e.g., AP) can assign a first RU (e.g., 26 / 52 / 106 / 242-RU, etc.) and a second RU (e.g., 26 / 52 / 106 / 242-RU, etc.) to a second STA via trigger information (e.g., trigger frame or TRS (Trigger Response Scheduler)). The first STA can then send a first trigger-based (TB) PPDU based on the first RU, and the second STA can send a second TB PPDU based on the second RU. The first TB PPDU / second TB PPDU can be sent to the AP at the same time interval.

[0164] For example, when DL MU PPDU is configured, the STA (e.g., AP) that sends DL MU PPDU can assign the first RU (e.g., 26 / 52 / 106 / 242-RU, etc.) to the first STA and assign the second RU (e.g., 26 / 52 / 106 / 242-RU, etc.) to the second STA.

[0165] EHT-SIG field

[0166] The EHT-SIG field of a 20 MHz EHT MU PPDU includes one EHT-SIG content channel. For multi-user OFDMA and non-OFDMA transmissions, the EHT-SIG field of a 40 MHz or 80 MHz EHT MU PPDU includes two EHT-SIG content channels. For multi-user OFDMA and non-OFDMA transmissions, the EHT-SIG field of a 160 MHz or larger EHT MU PPDU contains two EHT-SIG content channels per 80 MHz frequency sub-block. When the bandwidth of the EHT MU PPDU used for OFDMA transmission is wider than 80 MHz, the EHT-SIG content channels per 80 MHz frequency sub-block can carry different information.

[0167] Each EHT-SIG content channel may include a common field and a user-specific field, wherein, depending on the PPDU frequency bandwidth, the common field may include one or two RU allocation subfields.

[0168] For OFDMA transmission, the common field of the EHT-SIG content channel can include information for RU allocation, such as the RU allocation to be used in the EHT modulation field of the PPDU, the RUs allocated to MU-MIMO, and the number of users in the MU-MIMO allocation. When the bandwidth is 20 / 30 / 80 MHz, the common field can consist of one common coding block, and the common coding block can include one or two RU allocation-A subfields. When the bandwidth is 160 MHz, the common field can consist of two common coding blocks, and the first common coding block can include two RU allocation-A subfields, and the second common coding block can include two RU allocation-B subfields. When the bandwidth is 320 MHz, the common field can consist of two common coding blocks, and the first common coding block can include two RU allocation-A subfields, and the second common coding block can include six RU allocation-B subfields.

[0169] In non-OFDMA transmissions, the common fields of the EHT-SIG content channel may not include the RU allocation subfield.

[0170] The RU allocation-A subfield of the EHT-SIG content channel corresponding to the 20 MHz frequency subchannel can indicate the RU or MRU allocation, including the size of the RU / MRU and its arrangement in the frequency domain. The RU allocation-A subfield can also indicate the information necessary to calculate the number of users allocated to each RU / MRU.

[0171] The RU allocation-B subfield of the EHT-SIG content channel corresponding to the 20 MHz frequency subchannel can indicate the RU or MRU allocation, including the size of the RU / MRU and its arrangement in the frequency domain. The RU allocation-B subfield can also indicate the information necessary to calculate the number of users allocated to each RU / MRU.

[0172] The RU allocation-A subfield and the RU allocation-B subfield can both be referred to as RU allocation subfields located in different common coding blocks.

[0173] For OFDMA transmissions wider than 80 MHz, the RU allocation subfield for each 80 MHz frequency subblock can convey consistent RU or MRU size and arrangement information for the entire PPDU.

[0174] Table 6 illustrates the number of user fields per RU or MRU associated with user-specific fields within the same EHT SIG content channel, and the mapping from the 9-bit RU allocation subfield to RU allocation.

[0175] [Table 6]

[0176] Referring to Table 6, for RU allocation subfields with a value greater than or equal to 64, y2y1y0=000-111 indicates the number of user fields in the EHT-SIG content channel including the corresponding 9-bit RU allocation subfield. The binary vector y2y1y0 indicates the number of N in the EHT-SIG content channel containing the corresponding 9-bit RU allocation subfield. user (r,c)=2 2 × y² + 2 1 × y1+y0+ 1 user field.

[0177] In Table 6, the number of entries can represent the number of RU allocation subfield values ​​referring to the same RU allocation used in the frequency domain. However, due to different RU allocation subfield values, different numbers of user fields can be included in the user-specific fields of the same EHT-SIG content channel as that RU allocation subfield.

[0178] If the RU allocation subfield in Table 6 has a value that is specified as ignored, then STA can skip the N indicated by the subfield value. user (r, c) user fields and continue processing the EHT-SIG field.

[0179] Table 7 illustrates the RU or MRU associated with each RU allocation subfield and PPDU bandwidth for each EHT-SIG content channel.

[0180] [Table 7]

[0181] Table 8 shows an example of the index for empty subcarriers of each RU size when the channel bandwidth is 20 MHz and 40 MHz.

[0182] [Table 8]

[0183] Table 9 shows examples of the indexes for empty subcarriers of each RU size when the channel bandwidth is 80 MHz, 160 MHz, and 320 MHz.

[0184] [Table 9]

[0185] Spatial Modulation

[0186] To enhance SU-MIMO (Single-User MIMO), the number of LTFs can be extended, and limited singular feedback can be reported within the SU-type CSI (Channel State Information) report. Spatial modulation can transmit additional antenna selection bits along with data bits. Multilayer transmission with different MCS (Modulation and Coding Schemes) for each TX stream is possible. An AP can typically have eight or more TX antennas, but a STA may be limited by the number of RX antennas. For example, more than two RX antennas are rarely seen in a typical smartphone. Therefore, the throughput of SU-MIMO between a single AP and a single STA is limited by the number of RX antennas. To address this issue, spatial modulation (SM) can be used. By transmitting additional antenna selection bits along with data bits, spatial modulation can achieve improved throughput and is applicable to single AP and single STA use cases where the number of TX antennas is greater than the number of RX antennas.

[0187] In SU-MIMO transmission, the transmission rank is limited by the number of RF (radio frequency) chains within the RX (receiver). That is, the number of available TX RF chains is equal to or greater than the number of RX RF chains.

[0188] When the number of TX RF chains exceeds the transmission rank, TX RF chains are randomly selected from the total available TX RF chains based on the transmission rank. The random selection of TX RF chains is determined by selection bits that are part of the source data. Additionally, TX RF chains are randomly selected for each subcarrier.

[0189] Assume two RX antennas with four TX (i.e., four TX RF chains) and rank-2 transmission (i.e., the number of spatial streams (N)). ss =2).

[0190] Instead of applying a 4×2 Q matrix to map the two spatial streams to four TX antennas, two TX antennas can be arbitrarily selected according to Table 10 below.

[0191] Table 10 illustrates the two antenna selection (AS) bits used to select two TX antennas from four available TX antennas.

[0192] [Table 10]

[0193] In this case, due to the number of spatial flows (N) SS Since the MCS is 2, the two streaming data bits in each subcarrier are called d0 and d1. Here, depending on the MCS of the data, d0 or d1 can be a quadrature amplitude modulation (QAM) symbol.

[0194] For example, if the selected TXs are TX0 and TX1, then d0 is sent from TX0 and d1 is sent from TX1, while TX2 and TX3 can send empty data when there is no energy.

[0195] As another example, if the selected TXs are TX0 and TX3, then d0 is sent from TX0 and d1 is sent from TX3, while TX1 and TX2 can send empty data without energy.

[0196] Since the antenna selection bits are not encoded or interleaved, this information can have the same effect as MCS 3 transmission of data information in terms of total information bits.

[0197] Spatial modulation (SM) on the TX side can be performed as follows.

[0198] Figure 11 A transmitter block diagram according to one embodiment of the present disclosure is illustrated.

[0199] Reference Figure 11 A scrambler scrambles data to reduce the probability of long sequences of zero or one.

[0200] When using binary convolutional code (BCC) encoding, the bit parser (or encoder parser) polls N bits in a round-robin fashion. ES The number of BCC encoders used for the data field is used to demultiplex the scrambled bits between the BCC encoders.

[0201] Forward error correction (FEC) encoders encode data to achieve error correction. An FEC encoder may include a binary composite encoder followed by a punching device, or it may include a low-density parity check (LDPC) encoder.

[0202] The stream parser divides the encoder's output into blocks and sends them to other interleavers and mapping devices. The sequence of bits sent to the interleaver is called the spatial stream (SS).

[0203] The interleaver interleaves the bits of each spatial stream (SS) (changing the order of the bits) to prevent long sequences of adjacent noise bits from being input to the BCC decoder. Here, interleaving is only applied when using BCC encoding.

[0204] The constellation mapper maps the bit sequence of each spatial stream (SS) to constellation points (complex numbers).

[0205] The Inverse Discrete Fourier Transform (IDFT) transforms a block of constellation points into a block of time.

[0206] Cyclic shift diversity (CSD) can be inserted to prevent unwanted beamforming. CSD insertion can be performed before or after IDFT. There are three types of cyclic shifts.

[0207] Guard interval (GI) insertion adds its own cyclic extension before the symbol.

[0208] Spatial antenna streams (SAS) can be introduced into WLANs to achieve spatial modulation (SM). That is, through spatial mapping on the TX side, the spatial stream (SS) is mapped to the spatial antenna stream (SAS), and this stream can be mapped to the TX antenna.

[0209] Here, the spatial stream (SS) is aligned with the transmission rank and can be less than or equal to the number of RX. Additionally, the SS can be mapped to the SAS via the SM. The SAS can be mapped via a predefined method for the TX antennas, and the number of TX antennas can be equal to or greater than the number of SAS.

[0210] Antenna selection bits may not be encoded or interleaved. That is, antenna selection bits can be directly passed from the bit resolver to the spatial map. Therefore, in terms of total information bits, this information can have the same effect as MCS 3 transmission of data information.

[0211] Cyclic shift diversity (CSD) can be applied to SS before spatial mapping.

[0212] The number of LTFs can depend on the number of SASs available rather than the number of SSs. LTF extensions can be applied based on P matrix extensions (e.g., for the case of 4 SASs, a 4×4 or 4×8 P matrix can be applied).

[0213] The linear operating range of the TX power amplifier must be flexible enough to support the case where the maximum TX power is split across the flow between SS and SAS.

[0214] Information may be needed to indicate that the frame / PPDU is an SM frame / PPDU, which will be explained below with reference to the accompanying drawings.

[0215] Figure 12 An example of a PPDU format according to one embodiment of the present disclosure is shown.

[0216] Reference Figure 12RL-SIG (repeated L-SIG) is included after L-LTF, L-STF and L-SIG, followed by UHR-SIG field, UHR-STF and UHR-LTF (1, ..., N), followed by data field and FCS.

[0217] An SM frame indication can be included in the SIG field to indicate that the frame / PPDU is an SM frame / PPDU. For example, an SM frame indication can be added within U-SIG or UHR-SIG, where a 1-bit subfield is used for the SM frame indication.

[0218] Additionally, the quantity of SAS can be indicated by the SIG field (e.g., U-SIG or UHR-SIG).

[0219] Figure 13 A receiver block diagram according to one embodiment of the present disclosure is illustrated.

[0220] Figure 13 Each component of the receiver in the process can perform operations with... Figure 11 The corresponding component of the transmitter in the diagram performs the opposite operation, and its detailed description is omitted.

[0221] The antenna selection (AS) bit is detected on the RX side using maximum likelihood (ML) detection. The log-likelihood ratio (LLR) for the AS bit is calculated as follows.

[0222] [Formula 1]

[0223] In Equation 1, It is an LLR selected for the i-th antenna bit, where the received signal is a vector Y across the RX stream, and It is the channel matrix for the selected set of antennas. This indicates the selected antenna bit selection. This represents the set of antennas when the i-th antenna bit is selected as 1. It is the QAM constellation collection, and It refers to the entire QAM constellation set.

[0224] Referring to the examples in Table 10, if the first AS bit is "1", the selected TX antenna pair can be (TX0, TX3) or (TX1, TX2). Alternatively, if the first AS bit is "0", the selected TX antenna pair can be (TX0, TX1) or (TX2, TX2).

[0225] The Euclidean distance between the received signal and all possible QAM symbols can be calculated, multiplied by the estimated channel for the corresponding TX antenna pair, and then the minimum Euclidean distance can be selected. Here, the minimum Euclidean distance for AS bit "0" minus the Euclidean distance for AS bit "1" corresponds to the LLR for that AS bit position. In this way, once the LLR for each AS bit position is obtained, hard decision can be performed. That is, an LLR less than "0" indicates a bit "0" for that AS bit position.

[0226] Method of transmitting data bits using spatial modulation

[0227] As mentioned above, in order to increase the throughput in a wireless LAN system (802.11), a spatial modulation scheme can be applied to use an antenna combination to transmit additional data bits in each subcarrier.

[0228] This disclosure proposes a method for transmitting data using spatial modulation. Specifically, to minimize the implementation complexity of decoding additional data bits at the receiver and the implementation complexity related to antenna selection at the transmitter when applying spatial modulation, a simplified spatial modulation method is proposed, which limits the size of the data bits transmitted via spatial modulation (e.g., 1 bit or 2 bits). An antenna combination scheme and a signaling scheme for implementing this are also proposed.

[0229] As mentioned above, applying spatial modulation schemes can improve throughput because, in each subcarrier, not only is data mapped to specific constellation points of the information to be transmitted according to the MCS, as in conventional methods, but additional data bits can also be transmitted depending on the combination of antennas used. However, in this case, the receiver implementation may become complex to decode the additional data bits transmitted according to the spatial modulation scheme at the receiver, and the transmitter implementation for various antenna combinations may also become complex. Therefore, in order to improve throughput to a certain level while reducing the complexity of the transmitter and receiver, a simplified spatial modulation technique (called Type I spatial modulation) is proposed, which limits the size of the additional data transmitted according to the spatial modulation technique (e.g., limited to 1 bit), and the following presents an antenna combination method for this purpose.

[0230] Method 1: The transmitter can send an additional 1 bit of data by not using two specific antennas among multiple transmit antennas. In this case, any antenna other than the two unused antennas can always participate in the transmission. That is, if the two specific antennas are designated as antenna x and antenna y, then if antenna x is not used and all other antennas, including antenna y, are used, data "0" (i.e., bit value 0) can be sent (i.e., the receiver interprets / identifies that data "0" has been sent), and if antenna y is not used and all other antennas, including antenna x, are used, data "1" (i.e., bit value 1) can be sent (i.e., the receiver interprets / identifies that data "1" has been sent). Alternatively, the opposite can be true.

[0231] Here, as an example of two unused antennas, the antenna with the first index and the antenna with the last index can be mapped to antenna x and antenna y, respectively.

[0232] In this case, a relatively large number of antennas can be used in the transmitter compared to the two methods described below, thus allowing for additional performance gains.

[0233] Method 2: The transmitter can transmit 1 bit of data by using a combination of antennas with even-numbered indices and a combination of antennas with odd-numbered indices, respectively. For example, the combination of antennas with even-numbered indices can be used to transmit data "0" (i.e., bit value 0) (i.e., the receiver interprets / identifies that data "0" has been transmitted), and the combination of antennas with odd-numbered indices can be used to transmit data "1" (i.e., bit value 1) (i.e., the receiver interprets / identifies that data "1" has been transmitted). Alternatively, the opposite can be true.

[0234] According to this method, since there are no overlapping antennas among the different antenna combinations used to transmit additional data bits, decoding the corresponding data bits at the receiver can be easier compared to method 1.

[0235] Method 3: Assume the number of transmitting antennas is N (where N is an integer greater than 0). In this case, the transmitter can use either floor(N / 2) (floor(x) is the largest integer not greater than x) or ceil(N / 2) (ceil(x) is the smallest integer not less than x) antenna combinations starting with the antenna with the lowest index, and the remaining antenna combinations to transmit 1 bit of data. For example, data “0” can be transmitted using either floor(N / 2) or ceil(N / 2) antenna combinations starting with the antenna with the lowest index (i.e., interpreted / identified as data “0” at the receiver), and data “1” can be transmitted using the remaining antenna combinations (i.e., interpreted / identified as data “0” at the receiver). Alternatively, it can be the opposite.

[0236] Similar to Method 2, since there are no overlapping antennas used between the different antenna combinations used to transmit additional data bits, decoding the corresponding data bits at the receiver can be easier compared to Method 1.

[0237] In this disclosure, various signaling methods can be proposed by considering simplified spatial modulation methods.

[0238] For example, the proposed subfield described below can be included in the common field of U-SIG or UHR-SIG or in the user field of UHR-SIG. If included in the common field of U-SIG or UHR-SIG, it can indicate whether spatial modulation is applied to the entire PPDU (i.e., if spatial modulation is applied, it is applied to the entire PPDU). On the other hand, if applied to the user field of UHR-SIG, it can indicate whether spatial modulation is applied to each RU / MRU to which a particular STA is assigned (i.e., spatial modulation is applied individually to each RU / MRU assigned to each STA). Considering OFDMA methods, the latter may be preferred, while the former may be advantageous in non-OFDMA transmissions and may also be preferred in terms of overhead.

[0239] Signaling method 1: can be defined as a 1-bit subfield for indicating spatial modulation (e.g., the SM flag subfield or other names may be used; for ease of explanation, it is referred to as the SM flag subfield) and / or include a subfield for indicating the size of a specific bit of additional data bits during spatial modulation (e.g., the SM data size subfield or other names may be used; for ease of explanation, it is referred to as the SM data size subfield).

[0240] For example, if the size of the additional data bits transmitted via spatial modulation is defined as up to 2 bits, the SM data size subfield may include 1 bit (e.g., 0 indicates a size of 1 additional data bit, i.e., simplified spatial modulation, and 1 indicates a size of 2 additional data bits, i.e., general spatial modulation (i.e., referred to as type 2 spatial modulation)).

[0241] Alternatively, if only one additional data bit size (e.g., 1 bit) is defined for spatial modulation, then the SM data size subfield does not need to be defined.

[0242] Additionally, if the antenna combination scheme used for simplified spatial modulation is fixed to one type, the additional subfield may not be necessary; however, if not, a subfield indicating the antenna combination scheme used for simplified spatial modulation can be defined (e.g., a simplified spatial modulation (simplified SM) subfield or other names can be used; for ease of explanation below, it will be referred to as the simplified SM subfield). For example, if all three schemes described above are used, the simplified spatial modulation subfield can be defined as 2 bits (e.g., value 0 indicates scheme 1, value 1 indicates scheme 2, value 2 indicates scheme 3, and value 3 is reserved). Alternatively, since there is no significant difference between method 2 and method 3, if they are defined as only one of the two (i.e., the available antenna combinations are defined as {method 1 and method 2} or {method 1 and method 3}), the simplified spatial modulation subfield can be defined as 1 bit (e.g., value 0 indicates method 1, and value 1 indicates method 2 or method 3).

[0243] If all three subfields mentioned above are defined, the SM data size subfield can have meaning when the SM flag subfield indicates that spatial modulation has been applied. In this case, the simplified SM subfield can have meaning when the SM data size subfield indicates the bit size corresponding to simplified spatial modulation.

[0244] Therefore, when the SM flag subfield indicates that spatial modulation is not applied, the SM data size subfield and the simplified SM subfield can be reserved or used for other purposes. Additionally, when the SM flag subfield indicates that spatial modulation is applied but the SM data size subfield does not indicate the bit size of the simplified spatial modulation, the simplified SM subfield can be reserved or used for other purposes.

[0245] In other words, the use of the SM data size subfield and the simplified SM subfield can be determined by the value of the SM flag subfield. Additionally, the use of the simplified SM subfield can be determined by the value of the SM data size subfield.

[0246] Furthermore, considering cases where the above two subfields are defined in addition to simplifying the SM subfield, the SM data size subfield can be meaningful if the SM flag subfield indicates that spatial modulation has been applied. If the SM flag subfield indicates that spatial modulation has not been applied, the SM data size subfield can be reserved or used for other purposes. In other words, the use of the SM data size subfield can be determined by the value of the SM flag subfield.

[0247] Furthermore, considering the case where the above two subfields are defined in addition to the SM data size subfield, the simplified SM subfield can be meaningful if the SM flag subfield indicates that spatial modulation has been applied. If the SM flag subfield indicates that spatial modulation has not been applied, the simplified SM subfield can be reserved or used for other purposes. In other words, the use of the simplified SM subfield can be determined by the value of the SM flag subfield.

[0248] Compared to signaling methods 2 and 3 described below, signaling method 1 can reduce overhead.

[0249] Signaling Method 2: The 1-bit subfield used for spatial modulation indication in Signaling Method 1 (which may be called SM flag subfield or other names; for ease of explanation below) remains unchanged and can be defined as a subfield that integrates the SM data size subfield and the simplified SM subfield (which may be called SM type subfield or other names; for ease of explanation below).

[0250] The content of SM type subfields can be configured in various ways as follows.

[0251] For example, if simplified spatial modulation scheme 1, simplified spatial modulation scheme 2, and simplified spatial modulation scheme 3 are defined / supported, and 2-bit spatial modulation is defined / supported, then the SM type subfield can be defined as 2 bits. In this case, for example, a value of 0 can indicate simplified spatial modulation scheme 1, a value of 1 can indicate simplified spatial modulation scheme 2, a value of 2 can indicate simplified spatial modulation scheme 3, and a value of 3 can indicate 2-bit spatial modulation.

[0252] As another example, if only Simplified Spatial Modulation Scheme 1, Simplified Spatial Modulation Scheme 2, and Simplified Spatial Modulation Scheme 3 are defined / supported, then the SM type subfield can be defined as 2 bits. In this case, for example, a value of 0 can indicate Simplified Spatial Modulation Scheme 1, a value of 1 can indicate Simplified Spatial Modulation Scheme 2, a value of 2 can indicate Simplified Spatial Modulation Scheme 3, and a value of 3 can be reserved.

[0253] As another example, if simplified spatial modulation scheme 1 is defined / supported, only one of schemes 2 and 3 is defined / supported, and 2-bit spatial modulation is defined / supported, then the SM type subfield can be defined as 2 bits. In this case, for example, a value of 0 can indicate simplified spatial modulation scheme 1, a value of 1 can indicate simplified spatial modulation scheme 2 or simplified spatial modulation scheme 3, a value of 2 can indicate 2-bit spatial modulation, and a value of 3 can be reserved.

[0254] As another example, if simplified spatial modulation scheme 1 is defined / supported and only one of schemes 2 and 3 is defined / supported, then the SM type subfield can be defined as 1 bit. In this case, for example, a value of 0 can indicate simplified spatial modulation scheme 1, and a value of 1 can indicate simplified spatial modulation scheme 2 or simplified spatial modulation scheme 3.

[0255] As another example, if only one of the simplified spatial modulation schemes (i.e., any one of schemes 1 to 3) is defined / supported and 2-bit spatial modulation is defined / supported, then the SM type subfield can be defined as 1 bit. In this case, for example, a value of 0 can indicate a simplified spatial modulation scheme, and a value of 1 can indicate 2-bit spatial modulation.

[0256] As another example, if only one of the simplified spatial modulation schemes is defined / supported (i.e., any one of schemes 1 to 3), the SM type subfield can be defined as 1 bit. In this case, for example, a value of 0 indicates a simplified spatial modulation scheme, and 1 can be reserved.

[0257] If the SM flag subfield indicates that spatial modulation has been applied, then the SM type subfield can have meaning. That is, if the SM flag subfield indicates that spatial modulation has not been applied, then the SM type subfield can be reserved or used for other purposes. In other words, the use of the SM type subfield can be determined by the value of the SM flag subfield.

[0258] Compared to signaling scheme 3 described below, signaling scheme 2 described above can reduce overhead.

[0259] Signaling Method 3: All subfields of Signaling Method 1 can be integrated to indicate SM-related information. The corresponding subfield (which may be called SM subfield or other names; for ease of explanation, it will be referred to as SM subfield below) can be defined by a specific number of bits, where a value of 0 indicates that spatial modulation is not applied, and the remaining values ​​can indicate the spatial modulation type, the simplified spatial modulation method, the size of the data transmitted using spatial modulation, etc.

[0260] For example, if simplified spatial modulation scheme 1, simplified spatial modulation scheme 2, and simplified spatial modulation scheme 3 are defined / supported, and 2-bit spatial modulation is defined, then the SM subfield can be defined by 3 bits. In this case, for example, value 0 indicates that spatial modulation is not applied, value 1 indicates simplified spatial modulation scheme 1, value 2 indicates simplified spatial modulation scheme 2, value 3 indicates simplified spatial modulation scheme 3, value 4 indicates 2-bit spatial modulation, and the remaining values ​​5 to 7 can be reserved.

[0261] As another example, when only simplified spatial modulation scheme 1 and simplified spatial modulation scheme 3 are defined / supported (i.e., 2-bit spatial modulation is not defined / supported), the SM subfield can be defined as 2 bits. In this case, for example, a value of 0 indicates that spatial modulation is not applied, a value of 1 indicates simplified spatial modulation scheme 1, a value of 2 indicates simplified spatial modulation scheme 2, and a value of 3 indicates simplified spatial modulation scheme 3.

[0262] As another example, when a simplified spatial modulation scheme 1 is defined / supported and only one of schemes 2 and 3 is defined / supported, and 2-bit spatial modulation is defined / supported, the SM subfield can be defined as 2 bits. In this case, for example, a value of 0 indicates that no spatial modulation is applied, a value of 1 indicates simplified spatial modulation scheme 1, a value of 2 indicates simplified spatial modulation scheme 2 or simplified spatial modulation scheme 3, and a value of 3 indicates 2-bit spatial modulation.

[0263] As another example, if simplified spatial modulation scheme 1 is defined / supported and only one of schemes 2 and 3 is defined / supported, then the SM subfield can be defined as 2 bits. In this case, for example, a value of 0 indicates that spatial modulation is not applied, a value of 1 indicates simplified spatial modulation scheme 1, a value of 2 indicates simplified spatial modulation scheme 2 or simplified spatial modulation scheme 3, and a value of 3 can be reserved.

[0264] As another example, if only one of the simplified spatial modulation schemes is defined and 2-bit spatial modulation is defined, the SM subfield can be defined as 2 bits. In this case, for example, a value of 0 indicates that no spatial modulation is applied, a value of 1 indicates a simplified spatial modulation scheme, a value of 2 indicates 2-bit spatial modulation, and a value of 3 can be reserved.

[0265] As another example, if only one of the simplified spatial modulation schemes is defined, the SM subfield can be defined as 1 bit. In this case, for example, a value of 0 indicates that no spatial modulation is applied, and a value of 1 indicates a simplified spatial modulation scheme.

[0266] The signaling scheme 3 described above is simpler than the previously described signaling schemes 1 and 2, and is therefore likely to be desirable in terms of implementation.

[0267] Although various examples have been described for ease of explanation only by considering / assuming that the size of the additional data bits that can be transmitted using spatial modulation in the various signaling methods described above, this disclosure is not limited thereto. That is, the size of the additional data bits that can be transmitted using spatial modulation can be considered to be 3 bits or more, and in this case, the bit size of the subfields mentioned above can be increased.

[0268] Figure 14 The operation of a transmitting apparatus for a PPDU transmitting and receiving method according to one embodiment of the present disclosure is illustrated.

[0269] Figure 14 The operation of a transmitting device based on the previously proposed method is illustrated. Figure 14 The examples in this document are for illustrative purposes only and are not intended to limit the scope of this disclosure. Depending on the circumstances and / or configuration, they may be omitted. Figure 14 Some of the steps shown.

[0270] Reference Figure 14 The transmitting device generates a PPDU (S1401).

[0271] Here, the transmitting device of the PPDU can be an AP or a non-AP STA, and the receiving device of the PPDU can be an AP or a non-AP STA. For ease of explanation, the transmitting device can be referred to as the first STA, and the receiving device can be referred to as the second STA.

[0272] The transmitting device can obtain the aforementioned information regarding tone planning and / or spatial modulation. As described above, the information regarding tone planning may include the size and location of the RU, control information associated with the RU, information about the frequency band including the RU, and information about the STA receiving the RU, etc. Additionally, the information regarding spatial modulation may include information about specific antenna combinations. This information can be obtained through trigger frames when transmitting TB PPDUs.

[0273] Furthermore, the transmitting device can configure / generate a PPDU based on the obtained control information. The steps of configuring / generating a PPDU may include configuring / generating each field of the PPDU. That is, step S1401 may include configuring one or more fields (e.g., U-SIG and UHR-SIG-A / B fields) that include control information regarding the tone plan. For example, step S1401 may include configuring a field that includes control information indicating the bandwidth of the PPDU and / or configuring a field that includes control information indicating the size / location (e.g., N-bitmap) of the RU / MRU and / or configuring a field that includes the identifier (e.g., AID) of the STA receiving the RU / MRU. In the case of a TB PPDU, only some information may be included.

[0274] Additionally, step S1401 may include generating an STF / LTF sequence transmitted via a specific RU / MRU. The STF / LTF sequence can be generated based on a pre-configured STF generation sequence / LTF generation sequence. Furthermore, step S1401 may include determining the number of symbols in the LTF based on spatial modulation information.

[0275] Additionally, step S1401 may include the step of generating a data field (i.e., MPDU) transmitted through a specific RU. Furthermore, step S1401 may include the step of determining the antenna combination transmitted from each subcarrier of the data field based on spatial modulation information.

[0276] According to embodiments of this disclosure, it is possible to... Figure 12 The example shows the configuration of the PPDU.

[0277] Furthermore, according to embodiments of this disclosure, one or more data bits can be mapped to each of the data subcarriers within the PPDU for data transmission based on the MCS. Additionally, an additional bit of data can be transmitted based on spatial modulation (e.g., simplified spatial modulation or first-type spatial modulation) using a combination of specific antennas in each of the aforementioned data subcarriers.

[0278] Here, in each of the data subcarriers, an additional bit of data can be transmitted depending on which of the two predetermined antennas is not used. For example, in each of the data subcarriers, if antenna x is not used, a value of 0 can be used to indicate additional data, and if antenna y is not used, a value of 1 can be used to indicate additional data.

[0279] Additionally, in each of the data subcarriers, an additional bit of data can be transmitted using both even-indexed and odd-indexed antenna combinations. For example, in each of the data subcarriers, if only even-indexed antennas are used, a value of 0 can indicate additional data, and if only odd-indexed antennas are used, a value of 1 can indicate additional data.

[0280] Additionally, in each of the data subcarriers, one bit of additional data can be transmitted by sequentially using a combination of some antennas, starting with the lowest-indexed antenna, and a combination of the remaining antennas. For example, in each data subcarrier, if only some antennas are used sequentially starting with the lowest-indexed antenna, the value 0 indicates additional data, and if only antennas with the remaining indices are used, the value 1 indicates additional data.

[0281] Additionally, the PPDU may include a first field indicating whether spatial modulation is applied to the PPDU transmission, and a second field indicating the bit size of the additional data transmitted using spatial modulation (e.g., 1 bit according to a first type of spatial modulation, or 2 or more bits according to a second type of spatial modulation). Furthermore, the PPDU may also include a third field indicating the antenna combination method used to transmit one bit of additional data.

[0282] Alternatively, the PPDU may include a first field indicating whether spatial modulation is applied to the PPDU transmission, the bit size of the additional data transmitted using spatial modulation (e.g., 1 bit according to a first type of spatial modulation or 2 or more bits according to a second type of spatial modulation), and a fourth field indicating the antenna combination method for transmitting one bit of additional data.

[0283] Alternatively, the PPDU may include a fifth field indicating whether spatial modulation is applied to the transmission of the PPDU, the bit size of the additional data transmitted using spatial modulation (e.g., 1 bit according to a first type of spatial modulation, or 2 or more bits according to a second type of spatial modulation), and the antenna combination method for transmitting one bit of additional data.

[0284] The transmitting device (i.e., the first STA) sends a PPDU to the receiving device (i.e., the second STA) (S1402).

[0285] Here, for the operation of S1402, the transmitting device (i.e., the first STA) may perform at least one of the following operations: cyclic shift diversity (CSD), spatial mapping, inverse discrete Fourier transform (IDFT) / inverse fast Fourier transform (IFFT) operation, guard interval (GI) insertion, etc.

[0286] Figure 14 The methods described in the examples can be derived from... Figure 1 The first device (100) is executed. For example, Figure 1 One or more processors (102) of the first device (100) can be configured to generate PPDUs and transmit them via a transceiver (106). Furthermore, one or more memories (104) of the first device (100) can store data executed when performed by one or more processors (102). Figure 14 The example or instructions of the method described in the example above.

[0287] Figure 15 The operation of a receiving apparatus for a PPDU transmission and reception method according to one embodiment of the present disclosure is illustrated.

[0288] Figure 15 The operation of a receiving device based on the previously proposed method is illustrated. Figure 15 The examples in this document are for illustrative purposes only and do not limit the scope of this disclosure. They may be omitted depending on the circumstances and / or configuration. Figure 15 Some of the steps shown.

[0289] Reference Figure 15 The receiving device receives the PPDU (S1501).

[0290] Here, the transmitting device of the PPDU can be an AP or a non-AP STA, and the receiving device of the PPDU can be an AP or a non-AP STA. For ease of explanation, the transmitting device can be referred to as the first STA, and the receiving device can be referred to as the second STA.

[0291] Here, the receiving device (i.e., the second STA) can receive all or part of the PPDU through step S1501. Here, for the operation of step S1501, the receiving device (i.e., the second STA) can perform operations to recover the results of the CSD, spatial mapping, IDFT / IFFT operations and GI insertion operations applied by the transmitting device (e.g., applied in step S1402 above).

[0292] The receiving device (i.e., the second STA) processes the PPDU (S1502).

[0293] Here, the receiving device (i.e., the second STA) can perform decoding of all or part of the PPDU. In addition, the receiving device (i.e., the second STA) can obtain control information related to the tone plan (i.e., RU) from the decoded PPDU.

[0294] More specifically, the receiving device can decode the x-SIG field of the PPDU based on conventional STF / LTF and obtain the information contained in the x-SIG field. For example, information about the various tone schemes (i.e., RUs) proposed in this disclosure can be included in the x-SIG field, and the receiving STA can obtain information about the tone scheme (i.e., RU) through the x-SIG field.

[0295] Furthermore, the receiving device (i.e., the second STA) can decode the remaining parts of the PPDU based on information about the obtained tone plan (i.e., RU). For example, the receiving device (i.e., the second STA) can decode the STF / LTF fields of the PPDU based on information about the tone plan (i.e., RU). Additionally, the receiving device (i.e., the second STA) can decode the data fields of the PPDU based on information about the tone plan (i.e., RU) and obtain the MPDU included in the data fields. It can also obtain information about the antenna combination and decode the data.

[0296] Additionally, the receiving device (i.e., the second STA) can perform processing operations to send the decoded data to a higher layer (e.g., the MAC layer). Furthermore, if signal generation is directed from the higher layer to the PHY layer in response to the data being sent to the higher layer, subsequent operations can be performed.

[0297] According to embodiments of this disclosure, it is possible to... Figure 12 The example shows the configuration of the PPDU.

[0298] Furthermore, according to embodiments of this disclosure, one or more data bits can be mapped to each of the data subcarriers within the PPDU for data transmission based on the MCS. Additionally, an additional bit of data can be transmitted based on spatial modulation (e.g., simplified spatial modulation or first-type spatial modulation) using a combination of specific antennas in each of the aforementioned data subcarriers.

[0299] Here, in each of the data subcarriers, an additional bit of data can be transmitted depending on which of the two predetermined antennas is not used. For example, in each of the data subcarriers, if antenna x is not used, a value of 0 can be used to indicate additional data, and if antenna y is not used, a value of 1 can be used to indicate additional data.

[0300] Additionally, in each of the data subcarriers, an additional bit of data can be transmitted using both even-indexed and odd-indexed antenna combinations. For example, in each of the data subcarriers, if only even-indexed antennas are used, a value of 0 can indicate additional data, and if only odd-indexed antennas are used, a value of 1 can indicate additional data.

[0301] Additionally, in each of the data subcarriers, one bit of additional data can be transmitted by sequentially using a combination of some antennas, starting with the lowest-indexed antenna, and a combination of the remaining antennas. For example, in each data subcarrier, if only some antennas are used sequentially starting with the lowest-indexed antenna, the value 0 indicates additional data, and if only antennas with the remaining indices are used, the value 1 indicates additional data.

[0302] Additionally, the PPDU may include a first field indicating whether spatial modulation is applied to the PPDU transmission, and a second field indicating the bit size of the additional data transmitted using spatial modulation (e.g., 1 bit according to a first type of spatial modulation, or 2 or more bits according to a second type of spatial modulation). Furthermore, the PPDU may also include a third field indicating the antenna combination method used to transmit one bit of additional data.

[0303] Alternatively, the PPDU may include a first field indicating whether spatial modulation is applied to the PPDU transmission, the bit size of the additional data transmitted using spatial modulation (e.g., 1 bit according to a first type of spatial modulation or 2 or more bits according to a second type of spatial modulation), and a fourth field indicating the antenna combination method for transmitting one bit of additional data.

[0304] Alternatively, the PPDU may include a fifth field indicating whether spatial modulation is applied to the transmission of the PPDU, the bit size of the additional data transmitted using spatial modulation (e.g., 1 bit according to a first type of spatial modulation, or 2 or more bits according to a second type of spatial modulation), and the antenna combination method for transmitting one bit of additional data.

[0305] Figure 15 The methods described in the examples can be derived from... Figure 1 The second device (200) is executed. For example, Figure 1 One or more processors (202) of the second device (200) can be configured to receive and process PPDUs via a transceiver (106). Furthermore, one or more memories (204) of the second device (200) can store data executed when performed by one or more processors (202). Figure 15 The example or instructions of the method described in the example above.

[0306] In conventional wireless LAN systems, data bits are mapped to each subcarrier based on a constellation mapping according to the MCS. However, according to the examples of this disclosure, additional data bits can be transmitted and received in each subcarrier based on spatial modulation using antenna combinations. Therefore, it is possible to achieve increased data transmission throughput and improved wireless communication efficiency.

[0307] The above embodiments combine the elements and features of this disclosure in a predetermined form. Unless otherwise expressly stated, each element or feature should be considered optional. Each element or feature may be implemented without being combined with other elements or features. Furthermore, embodiments of this disclosure may include combinations of some elements and / or features. The order of operations described in embodiments of this disclosure may be changed. Some elements or features of one embodiment may be included in other embodiments, or may be replaced by corresponding elements or features of other embodiments. Obviously, embodiments may include claims that are not explicitly referenced in the claims, or may be included as new claims after the application has been amended.

[0308] It will be apparent to those skilled in the art that this disclosure may be implemented in other specific forms without departing from its essential characteristics. Therefore, the above detailed description should not be construed as restrictive in every respect, but rather as illustrative. The scope of this disclosure should be determined by a reasonable interpretation of the appended claims, and all variations within the equivalent scope of this disclosure are included within its scope.

[0309] The scope of this disclosure includes software or machine-executable commands (e.g., operating systems, applications, firmware, programs, etc.) that operate in a device or computer according to methods of various embodiments, as well as non-transitory computer-readable media that cause software or commands to be stored and executable in a device or computer. Commands that can be used to program a processing system to perform the features described in this disclosure can be stored in a storage medium or a computer-readable storage medium, and the features described in this disclosure can be implemented by using a computer program product including such a storage medium. The storage medium may include, but is not limited to, high-speed random access memory, such as DRAM, SRAM, DDR RAM, or other random access solid-state storage devices, and may include non-volatile memory, such as one or more disk storage devices, optical disk storage devices, flash memory devices, or other non-volatile solid-state storage devices. The memory may optionally include one or more storage devices located remotely from the processor. The memory, or alternatively, the non-volatile memory devices in the memory include non-transitory computer-readable storage media. The features described in this disclosure can be stored in any machine-readable medium to control the hardware of a processing system and can be integrated into software and / or firmware that allows the processing system to interact with other mechanisms using the results of embodiments of this disclosure. Such software or firmware may include, but is not limited to, application code, device drivers, operating systems, and execution environments / containers.

[0310] Industrial applicability

[0311] The method presented in this disclosure is primarily described based on examples applied to IEEE 802.11-based systems (5G systems), but can be applied to various WLAN or wireless communication systems other than IEEE 802.11-based systems.

Claims

1. A method comprising the following steps: The first station (STA) generates a Physical Protocol Data Unit (PPDU), wherein one or more data bits are mapped to each of the data subcarriers within the PPDU for data transmission based on a modulation and coding scheme (MCS); and The PPDU is transmitted from the first STA to the second STA, wherein, in each of the data subcarriers, an additional bit of data is transmitted based on spatial modulation using a combination of specific antennas.

2. The method according to claim 1, wherein, In each of the data subcarriers, one bit of the additional data is transmitted depending on which of the two predetermined antennas is not used.

3. The method according to claim 1, wherein, In each of the data subcarriers, one bit of the additional data is transmitted using an even-indexed antenna combination and an odd-indexed antenna combination.

4. The method according to claim 1, wherein, In each of the data subcarriers, starting with the lowest indexed antenna, one bit of the additional data is transmitted sequentially using a combination of some antennas and the remaining antennas.

5. The method according to claim 1, wherein, The PPDU includes a first field indicating whether spatial modulation is applied to the PPDU transmission, and a second field indicating the bit size of the additional data transmitted using spatial modulation.

6. The method according to claim 5, wherein, The PPDU also includes a third field indicating an antenna combination method for transmitting one bit of the additional data.

7. The method according to claim 1, wherein, The PPDU includes a first field indicating whether spatial modulation is applied to the PPDU transmission, and a fourth field indicating the bit size of the additional data transmitted using spatial modulation and the antenna combination method for transmitting one bit of the additional data.

8. The method according to claim 1, wherein, The PPDU includes a fifth field, which indicates whether spatial modulation is applied to the PPDU transmission, the bit size of the additional data transmitted using spatial modulation, and the antenna combination method for transmitting one bit of the additional data.

9. A first-station STA device, the first STA device comprising: At least one transceiver; as well as At least one processor, said at least one processor being connected to said at least one transceiver, Wherein, the at least one processor is configured to: Generate a Physical Protocol Data Unit (PPDU), wherein one or more data bits are mapped to each of the data subcarriers within the PPDU for data transmission based on a modulation and coding scheme (MCS); and The PPDU is transmitted to the second STA, wherein, in each of the data subcarriers, an additional bit of data is transmitted based on spatial modulation using a combination of specific antennas.

10. A method comprising the following steps: The second STA receives the Physical Protocol Data Unit (PPDU) from the first STA. as well as The PPDU is processed. One or more data bits are mapped to each of the data subcarriers within the PPDU for data transmission based on a modulation and coding scheme (MCS), and In each of the data subcarriers, an additional bit of data is received based on spatial modulation using a combination of specific antennas.

11. A second-station STA device, the second STA device comprising: At least one transceiver; as well as At least one processor, said at least one processor being connected to said at least one transceiver, Wherein, the at least one processor is configured to: The second STA receives the Physical Protocol Data Unit (PPDU) from the first STA; and The PPDU is processed. One or more data bits are mapped to each of the data subcarriers within the PPDU for data transmission based on a modulation and coding scheme (MCS), and In each of the data subcarriers, an additional bit of data is received based on spatial modulation using a combination of specific antennas.

12. A processing apparatus configured to control a station (STA) in a wireless local area network (WLAN) system, the processing apparatus comprising: At least one processor; as well as At least one computer memory, operatively connected to the at least one processor, and storing instructions for performing the method according to any one of claims 1 to 8, based on execution by the at least one processor.

13. At least one non-transitory computer-readable medium, said at least one non-transitory computer-readable medium storing at least one instruction, wherein, The at least one instruction is executed by at least one processor to control the device to perform the method according to any one of claims 1 to 8 in a wireless local area network (WLAN) system.

Images