The present disclosure relates to a transmission or reception method and device based on resource unit allocation in a wireless local area network (WLAN) system.
New technologies for improving transmission rates, increasing bandwidth, improving reliability, reducing errors, and reducing latency have been introduced for a wireless LAN (WLAN). Among WLAN technologies, an Institute of Electrical and Electronics Engineers (IEEE) 802.11 series standard may be referred to as Wi-Fi. For example, technologies recently introduced to WLAN include enhancements for Very High-Throughput (VHT) of the 802.11ac standard, and enhancements for High Efficiency (HE) of the IEEE 802.11ax standard.
In order to provide a more improved wireless communication environment, the improvement technology for Extremely High Throughput (EHT) is being discussed. For example, technologies for Multiple Input Multiple Output (MIMO) supporting increased bandwidth, efficient utilization of multiple bands and increased spatial streams and for adjusting multiple access points (APs) are being studied, and in particular, various technologies for supporting traffic with low latency or real-time characteristics are being studied. Furthermore, new technologies are being discussed to support ultra high reliability (UHR), including improvements or extensions to EHT technology.
A technical object of the present disclosure is to provide a method and device for allocating a resource unit in a wireless LAN system.
An additional technical object of the present disclosure is to provide a method and device for performing uplink/downlink transmission and reception by defining and applying a resource unit/multi-resource unit considering wider bandwidth in a wireless LAN system.
The technical objects to be achieved by the present disclosure are not limited to the above-described technical objects, and other technical objects which are not described herein will be clearly understood by those skilled in the pertinent art from the following description.
A method performed by a station (STA) in a wireless LAN system according to an aspect of the present disclosure may comprise: receiving a physical layer protocol data unit (PPDU) including a SIG field for resource unit allocation related information from another STA; and obtaining a data field in the PPDU, based on the resource unit allocation related information. Herein, the resource unit allocation related information may indicate a specific candidate within a set including a pre-defined number of multiple RU (MRU) candidates for a bandwidth exceeding 320 MHz.
A method performed by a station (STA) in a wireless LAN system according to another aspect of the present disclosure may comprise: constructing a SIG field for resource unit allocation related information; and transmitting a physical layer protocol data unit (PPDU) including the SIG field to another STA. Herein, the resource unit allocation related information may indicate a specific candidate within a set including a pre-defined number of multiple RU (MRU) candidates for a bandwidth exceeding 320 MHz.
According to the present disclosure, a method and device for allocating a resource unit in a wireless LAN system may be provided.
According to the present disclosure, a method and device for performing uplink/downlink transmission and reception by defining and applying a resource unit/multi-resource unit considering wider bandwidth in a wireless LAN system may be provided.
Effects achievable by the present disclosure are not limited to the above-described effects, and other effects which are not described herein may be clearly understood by those skilled in the pertinent art from the following description.
The accompanying drawings, which are included as part of the detailed description to aid understanding of the present disclosure, provide embodiments of the present disclosure and together with the detailed description describe technical features of the present disclosure.
Hereinafter, embodiments according to the present disclosure will be described in detail by referring to accompanying drawings. Detailed description to be disclosed with accompanying drawings is to describe exemplary embodiments of the present disclosure and is not to represent the only embodiment that the present disclosure may be implemented. The following detailed description includes specific details to provide complete understanding of the present disclosure. However, those skilled in the pertinent art knows that the present disclosure may be implemented without such specific details.
In some cases, known structures and devices may be omitted or may be shown in a form of a block diagram based on a core function of each structure and device in order to prevent a concept of the present disclosure from being ambiguous.
In the present disclosure, when an element is referred to as being “connected”, “combined” or “linked” to another element, it may include an indirect connection relation that yet another element presents therebetween as well as a direct connection relation. In addition, in the present disclosure, a term, “include” or “have”, specifies the presence of a mentioned feature, step, operation, component and/or element, but it does not exclude the presence or addition of one or more other features, stages, operations, components, elements and/or their groups.
In the present disclosure, a term such as “first”, “second”, etc. is used only to distinguish one element from other element and is not used to limit elements, and unless otherwise specified, it does not limit an order or importance, etc. between elements.
Accordingly, within a scope of the present disclosure, a first element in an embodiment may be referred to as a second element in another embodiment and likewise, a second element in an embodiment may be referred to as a first element in another embodiment.
A term used in the present disclosure is to describe a specific embodiment, and is not to limit a claim. As used in a described and attached claim of an embodiment, a singular form is intended to include a plural form, unless the context clearly indicates otherwise. A term used in the present disclosure, “and/or”, may refer to one of related enumerated items or it means that it refers to and includes any and all possible combinations of two or more of them. In addition, “/” between words in the present disclosure has the same meaning as “and/or”, unless otherwise described.
Examples of the present disclosure may be applied to various wireless communication systems. For example, examples of the present disclosure may be applied to a wireless LAN system. For example, examples of the present disclosure may be applied to an IEEE 802.11a/g/n/ac/ax standards-based wireless LAN. Furthermore, examples of the present disclosure may be applied to a wireless LAN based on the newly proposed IEEE 802.11be (or EHT) standard. Examples of the present disclosure may be applied to an IEEE 802.11be Release-2 standard-based wireless LAN corresponding to an additional enhancement technology of the IEEE 802.11be Release-1 standard. Additionally, examples of the present disclosure may be applied to a next-generation standards-based wireless LAN after IEEE 802.11be. Further, examples of this disclosure may be applied to a cellular wireless communication system. For example, it may be applied to a cellular wireless communication system based on Long Term Evolution (LTE)-based technology and 5G New Radio (NR)-based technology of the 3rd Generation Partnership Project (3GPP) standard.
Hereinafter, technical features to which examples of the present disclosure may be applied will be described.
The first device 100 and the second device 200 illustrated in
The devices 100 and 200 illustrated in
Referring to
In addition, the first device 100 and the second device 200 may additionally support various communication standards (e.g., 3GPP LTE series, 5G NR series standards, etc.) technologies other than wireless LAN technology. In addition, the device of the present disclosure may be implemented in various devices such as a mobile phone, a vehicle, a personal computer, augmented reality (AR) equipment, and virtual reality (VR) equipment, etc. In addition, the STA of the present specification may support various communication services such as a voice call, a video call, data communication, autonomous-driving, machine-type communication (MTC), machine-to-machine (M2M), device-to-device (D2D), IoT (Internet-of-Things), etc.
A 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. A processor 102 may control a memory 104 and/or a transceiver 106 and may be configured to implement description, functions, procedures, proposals, methods and/or operation flow charts disclosed in the present disclosure. For example, a processor 102 may transmit a wireless signal including first information/signal through a transceiver 106 after generating first information/signal by processing information in a memory 104. In addition, a processor 102 may receive a wireless signal including second information/signal through a transceiver 106 and then store information obtained by signal processing of second information/signal in a memory 104. A memory 104 may be connected to a processor 102 and may store a variety of information related to an operation of a processor 102. For example, a memory 104 may store a software code including instructions for performing all or part of processes controlled by a processor 102 or for performing description, functions, procedures, proposals, methods and/or operation flow charts disclosed in the present disclosure. Here, a processor 102 and a memory 104 may be part of a communication modem/circuit/chip designed to implement a wireless LAN technology (e.g., IEEE 802.11 series). A transceiver 106 may be connected to a processor 102 and may transmit and/or receive a wireless signal through one or more antennas 108. A transceiver 106 may include a transmitter and/or a receiver. A transceiver 106 may be used together with a RF (Radio Frequency) unit. In the present disclosure, a device may mean a communication modem/circuit/chip.
A 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. A processor 202 may control a memory 204 and/or a transceiver 206 and may be configured to implement description, functions, procedures, proposals, methods and/or operation flows charts disclosed in the present disclosure. For example, a processor 202 may generate third information/signal by processing information in a memory 204, and then transmit a wireless signal including third information/signal through a transceiver 206. In addition, a processor 202 may receive a wireless signal including fourth information/signal through a transceiver 206, and then store information obtained by signal processing of fourth information/signal in a memory 204. A memory 204 may be connected to a processor 202 and may store a variety of information related to an operation of a processor 202. For example, a memory 204 may store a software code including instructions for performing all or part of processes controlled by a processor 202 or for performing description, functions, procedures, proposals, methods and/or operation flow charts disclosed in the present disclosure. Here, a processor 202 and a memory 204 may be part of a communication modem/circuit/chip designed to implement a wireless LAN technology (e.g., IEEE 802.11 series). A transceiver 206 may be connected to a processor 202 and may transmit and/or receive a wireless signal through one or more antennas 208. A transceiver 206 may include a transmitter and/or a receiver. A transceiver 206 may be used together with a RF unit. In the present disclosure, a device may mean a communication modem/circuit/chip.
Hereinafter, a hardware element of a device 100, 200 will be described in more detail. It is not limited thereto, but one or more protocol layers may be implemented by one or more processors 102, 202. For example, one or more processors 102, 202 may implement one or more layers (e.g., a functional layer such as PHY, MAC). One or more processors 102, 202 may generate one or more PDUs (Protocol Data Unit) and/or one or more SDUs (Service Data Unit) according to description, functions, procedures, proposals, methods and/or operation flow charts disclosed in the present disclosure. One or more processors 102, 202 may generate a message, control information, data or information according to description, functions, procedures, proposals, methods and/or operation flow charts disclosed in the present disclosure. One or more processors 102, 202 may generate a signal (e.g., a baseband signal) including a PDU, a SDU, a message, control information, data or information according to functions, procedures, proposals and/or methods disclosed in the present disclosure to provide it to one or more transceivers 106, 206. One or more processors 102, 202 may receive a signal (e.g., a baseband signal) from one or more transceivers 106, 206 and obtain a PDU, a SDU, a message, control information, data or information according to description, functions, procedures, proposals, methods and/or operation flow charts disclosed in the present disclosure.
One or more processors 102, 202 may be referred to as a controller, a micro controller, a micro processor or a micro computer. One or more processors 102, 202 may be implemented by a hardware, a firmware, a software, or their combination. In an example, one or more ASICs (Application Specific Integrated Circuit), one or more DSPs (Digital Signal Processor), one or more DSPDs (Digital Signal Processing Device), one or more PLDs (Programmable Logic Device) or one or more FPGAs (Field Programmable Gate Arrays) may be included in one or more processors 102, 202. Description, functions, procedures, proposals, methods and/or operation flow charts disclosed in the present disclosure may be implemented by using a firmware or a software and a firmware or a software may be implemented to include a module, a procedure, a function, etc. A firmware or a software configured to perform description, functions, procedures, proposals, methods and/or operation flow charts disclosed in the present 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. Description, functions, procedures, proposals, methods and/or operation flow charts disclosed in the present disclosure may be implemented by using a firmware or a software in a form of a code, an instruction and/or a set of instructions.
One or more memories 104, 204 may be connected to one or more processors 102, 202 and may store data, a signal, a message, information, a program, a code, an indication and/or an instruction in various forms. One or more memories 104, 204 may be configured with ROM, RAM, EPROM, a flash memory, a hard drive, a register, a cash memory, a computer readable storage medium and/or their combination. One or more memories 104, 204 may be positioned inside and/or outside one or more processors 102, 202. In addition, one or more memories 104, 204 may be connected to one or more processors 102, 202 through a variety of technologies such as a wire or wireless connection.
One or more transceivers 106, 206 may transmit user data, control information, a wireless signal/channel, etc. mentioned in methods and/or operation flow charts, etc. of the present disclosure to one or more other devices. One or more transceivers 106, 206 may receiver user data, control information, a wireless signal/channel, etc. mentioned in description, functions, procedures, proposals, methods and/or operation flow charts, etc. disclosed in the present disclosure from one or more other devices. For example, one or more transceivers 106, 206 may be connected to one or more processors 102, 202 and may transmit and receive a wireless signal. For example, one or more processors 102, 202 may control one or more transceivers 106, 206 to transmit user data, control information or a wireless signal to one or more other devices. In addition, one or more processors 102, 202 may control one or more transceivers 106, 206 to receive user data, control information or a wireless signal from one or more other devices. In addition, 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, a wireless signal/channel, etc. mentioned in description, functions, procedures, proposals, methods and/or operation flow charts, etc. disclosed in the present disclosure through one or more antennas 108, 208. In the present disclosure, one or more antennas may be a plurality of physical antennas or a plurality of logical antennas (e.g., an antenna port). One or more transceivers 106, 206 may convert a received wireless signal/channel, etc. into a baseband signal from a RF band signal to process received user data, control information, wireless signal/channel, etc. by using one or more processors 102, 202. One or more transceivers 106, 206 may convert user data, control information, a wireless signal/channel, etc. which are processed by using one or more processors 102, 202 from a baseband signal to a RF band signal. Therefor, one or more transceivers 106, 206 may include an (analogue) oscillator and/or a filter.
For example, one of the STAs 100 and 200 may perform an intended operation of an AP, and the other of the STAs 100 and 200 may perform an intended operation of a non-AP STA. For example, the transceivers 106 and 206 of
Hereinafter, downlink (DL) may mean a link for communication from an AP STA to a non-AP STA, and a DL PPDU/packet/signal may be transmitted and received through the DL. In DL communication, a transmitter may be part of an AP STA, and a receiver may be part of a non-AP STA. Uplink (UL) may mean a link for communication from non-AP STAs to AP STAs, and a UL PPDU/packet/signal may be transmitted and received through the UL. In UL communication, a transmitter may be part of a non-AP STA, and a receiver may be part of an AP STA.
The structure of the wireless LAN system may consist of be composed of a plurality of components. A wireless LAN supporting STA mobility transparent to an upper layer may be provided by interaction of a plurality of components. A Basic Service Set (BSS) corresponds to a basic construction block of a wireless LAN.
If the DS shown in
Membership of an STA in the BSS may be dynamically changed by turning on or off the STA, entering or exiting the BSS area, and the like. To become a member of the BSS, the STA may join the BSS using a synchronization process. In order to access all services of the BSS infrastructure, the STA shall be associated with the BSS. This association may be dynamically established and may include the use of a Distribution System Service (DSS).
A direct STA-to-STA distance in a wireless LAN may be limited by PHY performance. In some cases, this distance limit may be sufficient, but in some cases, communication between STAs at a longer distance may be required. A distributed system (DS) may be configured to support extended coverage.
DS means a structure in which BSSs are interconnected. Specifically, as shown in
A DS may support a mobile device by providing seamless integration of a plurality of BSSs and providing logical services necessary to address an address to a destination. In addition, the DS may further include a component called a portal that serves as a bridge for connection between the wireless LAN and other networks (e.g., IEEE 802.X).
The AP enables access to the DS through the WM for the associated non-AP STAs, and means an entity that also has the functionality of an STA. Data movement between the BSS and the DS may be performed through the AP. For example, STA2 and STA3 shown in
Data transmitted from one of the STA(s) associated with an AP to a STA address of the corresponding AP may be always received on an uncontrolled port and may be processed by an IEEE 802.1X port access entity. In addition, when a controlled port is authenticated, transmission data (or frames) may be delivered to the DS.
In addition to the structure of the DS described above, an extended service set (ESS) may be configured to provide wide coverage.
An ESS means a network in which a network having an arbitrary size and complexity is composed of DSs and BSSs. The ESS may correspond to a set of BSSs connected to one DS. However, the ESS does not include the DS. An ESS network is characterized by being seen as an IBSS in the Logical Link Control (LLC) layer. STAs included in the ESS may communicate with each other, and mobile STAs may move from one BSS to another BSS (within the same ESS) transparently to the LLC. APs included in one ESS may have the same service set identification (SSID). The SSID is distinguished from the BSSID, which is an identifier of the BSS.
The wireless LAN system does not assume anything about the relative physical locations of BSSs, and all of the following forms are possible. BSSs may partially overlap, which is a form commonly used to provide continuous coverage. In addition, BSSs may not be physically connected, and logically there is no limit on the distance between BSSs. In addition, the BSSs may be physically located in the same location, which may be used to provide redundancy. In addition, one (or more than one) IBSS or ESS networks may physically exist in the same space as one (or more than one) ESS network. 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, this may correspond to the form of an ESS network in the like.
In order for an STA to set up a link with respect to a network and transmit/receive data, it first discovers a network, performs authentication, establishes an association, and need to perform the authentication process for security. The link setup process may also be referred to as a session initiation process or a session setup process. In addition, the processes of discovery, authentication, association, and security setting of the link setup process may be collectively referred to as an association process.
In step S310, the STA may perform a network discovery operation. The network discovery operation may include a scanning operation of the STA. That is, in order for the STA to access the network, it needs to find a network in which it can participate. The STA shall identify a compatible network before participating in a wireless network, and the process of identifying a network existing in a specific area is called scanning.
Scanning schemes include active scanning and passive scanning.
Although not shown in
After the STA discovers the network, an authentication process may be performed in step S320. This authentication process may be referred to as a first authentication process in order to be clearly distinguished from the security setup operation of step S340 to be described later.
The authentication process includes a process in which the STA transmits an authentication request frame to the AP, and in response to this, the AP transmits an authentication response frame to the STA. An authentication frame used for authentication request/response corresponds to a management frame.
The authentication frame includes an authentication algorithm number, an authentication transaction sequence number, a status code, a challenge text, a robust security network (RSN), and a Finite Cyclic Group, etc. This corresponds to some examples of information that may be included in the authentication request/response frame, and may be replaced with other information or additional information may be further included.
The STA may transmit an authentication request frame to the AP. The AP may determine whether to allow authentication of the corresponding STA based on information included in the received authentication request frame. The AP may provide the result of the authentication process to the STA through an authentication response frame.
After the STA is successfully authenticated, an association process may be performed in step S330. The association process includes a process in which the STA transmits an association request frame to the AP, and in response, the AP transmits an association response frame to the STA.
For example, the association request frame may include information related to various capabilities, a beacon listen interval, a service set identifier (SSID), supported rates, supported channels, RSN, mobility domain, supported operating classes, Traffic Indication Map Broadcast request (TIM broadcast request), interworking service capability, etc. For example, the association response frame may include information related to various capabilities, status code, association ID (AID), supported rates, enhanced distributed channel access (EDCA) parameter set, received channel power indicator (RCPI), received signal to noise indicator (RSNI), mobility domain, timeout interval (e.g., association comeback time), overlapping BSS scan parameters, TIM broadcast response, Quality of Service (QOS) map, etc. This corresponds to some examples of information that may be included in the association request/response frame, and may be replaced with other information or additional information may be further included.
After the STA is successfully associated with the network, a security setup process may be performed in step S340. The security setup process of step S340 may be referred to as an authentication process through Robust Security Network Association (RSNA) request/response, and the authentication process of step S320 is referred to as a first authentication process, and the security setup process of step S340 may also simply be referred to as an authentication process.
The security setup process of step S340 may include, for example, a process of setting up a private key through 4-way handshaking through an Extensible Authentication Protocol over LAN (EAPOL) frame. In addition, the security setup process may be performed according to a security scheme not defined in the IEEE 802.11 standard.
In the wireless LAN system, a basic access mechanism of medium access control (MAC) is a carrier sense multiple access with collision avoidance (CSMA/CA) mechanism. The CSMA/CA mechanism is also called Distributed Coordination Function (DCF) of IEEE 802.11 MAC, and basically adopts a “listen before talk” access mechanism. According to this type of access mechanism, the AP and/or STA may perform Clear Channel Assessment (CCA) sensing a radio channel or medium during a predetermined time interval (e.g., DCF Inter-Frame Space (DIFS)), prior to starting transmission. As a result of the sensing, if it is determined that the medium is in an idle state, frame transmission is started through the corresponding medium. On the other hand, if it is detected that the medium is occupied or busy, the corresponding AP and/or STA does not start its own transmission and may set a delay period for medium access (e.g., a random backoff period) and attempt frame transmission after waiting. By applying the random backoff period, since it is expected that several STAs attempt frame transmission after waiting for different periods of time, collision may be minimized.
In addition, the IEEE 802.11 MAC protocol provides a Hybrid Coordination Function (HCF). HCF is based on the DCF and Point Coordination Function (PCF). PCF is a polling-based synchronous access method and refers to a method in which all receiving APs and/or STAs periodically poll to receive data frames. In addition, HCF has Enhanced Distributed Channel Access (EDCA) and HCF Controlled Channel Access (HCCA). EDCA is a contention-based access method for a provider to provide data frames to multiple users, and HCCA uses a non-contention-based channel access method using a polling mechanism. In addition, the HCF includes a medium access mechanism for improving QoS (Quality of Service) of the wireless LAN, and may transmit QoS data in both a Contention Period (CP) and a Contention Free Period (CFP).
Referring to
When the random backoff process starts, the STA continuously monitors the medium while counting down the backoff slots according to the determined backoff count value. When the medium is monitored for occupancy, it stops counting down and waits, and resumes the rest of the countdown when the medium becomes idle.
In the example of
As in the example of
A Quality of Service (QOS) STA may perform the backoff that is performed after an arbitration IFS (AIFS) for an access category (AC) to which the frame belongs, that is, AIFS[i] (where i is a value determined by AC), and then may transmit the frame. Here, the frame in which AIFS[i] can be used may be a data frame, a management frame, or a control frame other than a response frame.
As described above, the CSMA/CA mechanism includes virtual carrier sensing in addition to physical carrier sensing in which a STA directly senses a medium. Virtual carrier sensing is intended to compensate for problems that may occur in medium access, such as a hidden node problem. For virtual carrier sensing, the MAC of the STA may use a Network Allocation Vector (NAV). The NAV is a value indicating, to other STAs, the remaining time until the medium is available for use by an STA currently using or having the right to use the medium. Therefore, the value set as NAV corresponds to a period in which the medium is scheduled to be used by the STA transmitting the frame, and the STA receiving the NAV value is prohibited from accessing the medium during the corresponding period. For example, the NAV may be configured based on the value of the “duration” field of the MAC header of the frame.
In the example of
In order to reduce the possibility of collision of transmissions of multiple STAs in CSMA/CA based frame transmission operation, a mechanism using RTS/CTS frames may be applied. In the example of
Specifically, the STA1 may determine whether a channel is being used through carrier sensing. In terms of physical carrier sensing, the STA1 may determine a channel occupation idle state based on an energy level or signal correlation detected in a channel. In addition, in terms of virtual carrier sensing, the STA1 may determine a channel occupancy state using a network allocation vector (NAV) timer.
The STA1 may transmit an RTS frame to the STA2 after performing a backoff when the channel is in an idle state during DIFS. When the STA2 receives the RTS frame, the STA2 may transmit a CTS frame as a response to the RTS frame to the STA1 after SIFS.
If the STA3 cannot overhear the CTS frame from the STA2 but can overhear the RTS frame from the STA1, the STA3 may set a NAV timer for a frame transmission period (e.g., SIFS+CTS frame+SIFS+data frame+SIFS+ACK frame) that is continuously transmitted thereafter, using the duration information included in the RTS frame. Alternatively, if the STA3 can overhear a CTS frame from the STA2 although the STA3 cannot overhear an RTS frame from the STA1, the STA3 may set a NAV timer for a frame transmission period (e.g., SIFS+data frame+SIFS+ACK frame) that is continuously transmitted thereafter, using the duration information included in the CTS frame. That is, if the STA3 can overhear one or more of the RTS or CTS frames from one or more of the STA1 or the STA2, the STA3 may set the NAV accordingly. When the STA3 receives a new frame before the NAV timer expires, the STA3 may update the NAV timer using duration information included in the new frame. The STA3 does not attempt channel access until the NAV timer expires.
When the STA1 receives the CTS frame from the the STA2, the STA1 may transmit the data frame to the STA2 after SIFS from the time point when the reception of the CTS frame is completed. When the STA2 successfully receives the data frame, the STA2 may transmit an ACK frame as a response to the data frame to the STA1 after SIFS. The STA3 may determine whether the channel is being used through carrier sensing when the NAV timer expires. When the STA3 determines that the channel is not used by other terminals during DIFS after expiration of the NAV timer, the STA3 may attempt channel access after a contention window (CW) according to a random backoff has passed.
By means of an instruction or primitive (meaning a set of instructions or parameters) from the MAC layer, the PHY layer may prepare a MAC PDU (MPDU) to be transmitted. For example, when a command requesting transmission start of the PHY layer is received from the MAC layer, the PHY layer switches to the transmission mode and configures information (e.g., data) provided from the MAC layer in the form of a frame and transmits it. In addition, when the PHY layer detects a valid preamble of the received frame, the PHY layer monitors the header of the preamble and sends a command notifying the start of reception of the PHY layer to the MAC layer.
In this way, information transmission/reception in a wireless LAN system is performed in the form of a frame, and for this purpose, a PHY layer protocol data unit (PPDU) frame format is defined.
A basic PPDU frame may include a Short Training Field (STF), a Long Training Field (LTF), a SIGNAL (SIG) field, and a Data field. The most basic (e.g., non-High Throughput (HT)) PPDU frame format may consist of only L-STF (Legacy-STF), L-LTF (Legacy-LTF), SIG field, and data field. In addition, depending on the type of PPDU frame format (e.g., HT-mixed format PPDU, HT-greenfield format PPDU, VHT (Very High Throughput) PPDU, etc.), an additional (or different type) STF, LTF, and SIG fields may be included between the SIG field and the data field (this will be described later with reference to
The STF is a signal for signal detection, automatic gain control (AGC), diversity selection, precise time synchronization, and the like, and the LTF is a signal for channel estimation and frequency error estimation. The STF and LTF may be referred to as signals for synchronization and channel estimation of the OFDM physical layer.
The SIG field may include a RATE field and a LENGTH field. The RATE field may include information on modulation and coding rates of data. The LENGTH field may include information on the length of data. Additionally, the SIG field may include a parity bit, a SIG TAIL bit, and the like.
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 may be used for synchronization of the descrambler at the receiving end. 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 may be used to return the encoder to a 0 state. Padding bits may be used to adjust the length of a data field in a predetermined unit.
A MAC PDU is 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). The MAC frame may consist of MAC PDUs and be transmitted/received through the PSDU of the data part of the PPDU frame format.
The MAC header includes a Frame Control field, a Duration/ID field, an Address field, and the like. The frame control field may include control information required for frame transmission/reception. The duration/ID field may be set to a time for transmitting a corresponding frame or the like. For details of the Sequence Control, QoS Control, and HT Control subfields of the MAC header, refer to the IEEE 802.11 standard document.
A null-data packet (NDP) frame format means a frame format that does not include a data packet. That is, the NDP frame refers to a frame format that includes a physical layer convergence procedure (PLCP) header part (i.e., STF, LTF, and SIG fields) in a general PPDU frame format and does not include the remaining parts (i.e., data field). A NDP frame may also be referred to as a short frame format.
In standards such as IEEE 802.11a/g/n/ac/ax, various types of PPDUs have been used. The basic PPDU format (IEEE 802.11a/g) includes L-LTF, L-STF, L-SIG and Data fields. The basic PPDU format may also be referred to as a non-HT PPDU format.
The HT PPDU format (IEEE 802.11n) additionally includes HT-SIG, HT-STF, and HT-LFT(s) fields to the basic PPDU format. The HT PPDU format shown in
An example of the VHT PPDU format (IEEE 802.11ac) additionally includes VHT SIG-A, VHT-STF, VHT-LTF, and VHT-SIG-B fields to the basic PPDU format.
An example of the HE PPDU format (IEEE 802.11ax) additionally includes Repeated L-SIG (RL-SIG), HE-SIG-A, HE-SIG-B, HE-STF, HE-LTF(s), Packet Extension (PE) field to the basic PPDU format. Some fields may be excluded or their length may vary according to 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), and the HE-SIG-B is not included in the HE PPDU format for single user (SU). In addition, the HE trigger-based (TB) PPDU format does not include the HE-SIG-B, and the length of the HE-STF field may vary to 8 us. The Extended Range (HE ER) SU PPDU format does not include the HE-SIG-B field, and the length of the HE-SIG-A field may vary to 16 us.
Referring to
As shown in
As shown at the top of
The RU allocation of
In the example of
Just as RUs of various sizes are used in the example of
In addition, as shown, when used for a single user, a 484-RU may be used.
Just as RUs of various sizes are used in the example of
In addition, as shown, when used for a single user, 996-RU may be used, and in this case, 5 DC tones are inserted in common with HE PPDU and EHT PPDU.
EHT PPDUs over 160 MHz may be configured with a plurality of 80 MHz subblocks in
Here, the MRU corresponds to a group of subcarriers (or tones) composed of a plurality of RUs, and the plurality of RUs constituting the MRU may be RUs having the same size or RUs having different sizes. For example, a single MRU may 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. Here, the plurality of RUs constituting one MRU may correspond to small size (e.g., 26, 52, or 106) RUs or large size (e.g., 242, 484, or 996) RUs. That is, one MRU including a small size RU and a large size RU may not be configured/defined. In addition, a plurality of RUs constituting one MRU may or may not be consecutive in the frequency domain.
When an 80 MHz subblock includes RUs smaller than 996 tones, or parts of the 80 MHz subblock are punctured, the 80 MHz subblock may use RU allocation other than the 996-tone RU.
The RU of the present disclosure may be used for uplink (UL) and/or downlink (DL) communication. For example, when trigger-based UL-MU communication is performed, the STA transmitting the trigger (e.g., AP) may allocate a first RU (e.g., 26/52/106/242-RU, etc.) to a first STA and allocate a second RU (e.g., 26/52/106/242-RU, etc.) to a second STA, through trigger information (e.g., trigger frame or triggered response scheduling (TRS)). Thereafter, the first STA may transmit a first trigger-based (TB) PPDU based on the first RU, and the second STA may transmit a second TB PPDU based on the second RU. The first/second TB PPDUs may be transmitted to the AP in the same time period.
For example, when a DL MU PPDU is configured, the STA transmitting the DL MU PPDU (e.g., AP) may allocate a first RU (e.g., 26/52/106/242-RU, etc.) to a first STA and allocate a second RU (e.g., 26/52/106/242-RU, etc.) to a second STA. That is, the transmitting STA (e.g., AP) may transmit HE-STF, HE-LTF, and Data field for the first STA through the first RU and transmit HE-STF, HE-LTF, and Data field for the second STA through the second RU, in one MU PPDU,
Information on the allocation of RUs may be signaled through HE-SIG-B in the HE PPDU format.
As shown, the HE-SIG-B field may include a common field and a user-specific field. If HE-SIG-B compression is applied (e.g., full-bandwidth MU-MIMO transmission), the common field may not be included in HE-SIG-B, and the HE-SIG-B content channel may include only a user-specific field. If HE-SIG-B compression is not applied, the common field may be included in HE-SIG-B.
The common field may include information on RU allocation (e.g., RU assignment, RUs allocated for MU-MIMO, the number of MU-MIMO users (STAs), etc.)
The common field may include N*8 RU allocation subfields. Here, N is the number of subfields, N=1 in the case of 20 or 40 MHz MU PPDU, N=2 in the case of 80 MHz MU PPDU, N=4 in the case of 160 MHz or 80+80 MHz MU PPDU, etc. One 8-bit RU allocation subfield may indicate the size (26, 52, 106, etc.) and frequency location (or RU index) of RUs included in the 20 MHz band.
For example, if a value of the 8-bit RU allocation subfield is 00000000, it may indicate that nine 26-RUs are sequentially allocated in order from the leftmost to the rightmost in the example of
As an additional example, if the value of the 8-bit RU allocation subfield is 01000y2y1y0, it may indicate that one 106-RU and five 26-RUs are sequentially allocated from the leftmost to the rightmost in the example of
Basically, one user/STA may be allocated to each of a plurality of RUs, and different users/STAs may be allocated to different RUs. For RUs larger than a predetermined size (e.g., 106, 242, 484, 996-tones, . . . ), a plurality of users/STAs may be allocated to one RU, and MU-MIMO scheme may be applied for the plurality of users/STAs.
The set of user-specific fields includes information on how all users (STAs) of the corresponding PPDU decode their payloads. User-specific fields may contain zero or more user block fields. The non-final user block field includes two user fields (i.e., information to be used for decoding in two STAs). The final user block field contains one or two user fields. The number of user fields may be indicated by the RU allocation subfield of HE-SIG-B, the number of symbols of HE-SIG-B, or the MU-MIMO user field of HE-SIG-A. A User-specific field may be encoded separately from or independently of a common field.
In the example of
The user field may be constructed based on two formats. The user field for a MU-MIMO allocation may be constructed with a first format, and the user field for non-MU-MIMO allocation may be constructed with a second format. Referring to the example of
The user field of the first format (i.e., format for MU-MIMO allocation) may be constructed as follows. For example, out of all 21 bits of one user field, B0-B10 includes the user's identification information (e.g., STA-ID, AID, partial AID, etc.), B11-14 includes spatial configuration information such as the number of spatial streams for the corresponding user, B15-B18 includes Modulation and Coding Scheme (MCS) information applied to the Data field of the corresponding PPDU, B19 is defined as a reserved field, and B20 may include information on a coding type (e.g., binary convolutional coding (BCC) or low-density parity check (LDPC)) applied to the Data field of the corresponding PPDU.
The user field of the second format (i.e., the format for non-MU-MIMO allocation) may be constructed as follows. For example, out of all 21 bits of one user field, B0-B10 includes the user's identification information (e.g., STA-ID, AID, partial AID, etc.), B11-13 includes information on the number of spatial streams (NSTS) applied to the corresponding RU, B14 includes information indicating whether beamforming is performed (or whether a beamforming steering matrix is applied), B15-B18 includes Modulation and Coding Scheme (MCS) information applied to the Data field of the corresponding PPDU, B19 includes information indicating whether DCM (dual carrier modulation) is applied, and B20 may include information on a coding type (e.g., BCC or LDPC) applied to the Data field of the corresponding PPDU.
MCS, MCS information, MCS index, MCS field, and the like used in the present disclosure may be indicated by a specific index value. For example, MCS information may be indicated as index 0 to index 11. MCS information includes information on constellation modulation type (e.g., BPSK, QPSK, 16-QAM, 64-QAM, 256-QAM, 1024-QAM, etc.), and coding rate (e.g., ½, ⅔, ¾, ⅚, etc.). Information on a channel coding type (e.g., BCC or LDPC) may be excluded from the MCS information.
The PPDU of
The EHT MU PPDU of
In the EHT TB PPDU of
In the example of the EHT PPDU format of
A Subcarrier frequency spacing of L-STF, L-LTF, L-SIG, RL-SIG, Universal SIGNAL (U-SIG), EHT-SIG field (these are referred to as pre-EHT modulated fields) may be set to 312.5 kHz. A subcarrier frequency spacing of the EHT-STF, EHT-LTF, Data, and PE field (these are referred to as EHT modulated fields) may be set to 78.125 kHz. That is, the tone/subcarrier index of L-STF, L-LTF, L-SIG, RL-SIG, U-SIG, and EHT-SIG field may be indicated in units of 312.5 kHz, and the tone/subcarrier index of EHT-STF, EHT-LTF, Data, and PE field may be indicated in units of 78.125 kHz.
The L-LTF and L-STF of
The L-SIG field of
For example, the transmitting STA may apply BCC encoding based on a coding rate of ½ to 24-bit information of the L-SIG field. Thereafter, the transmitting STA may obtain 48-bit BCC coded bits. BPSK modulation may be applied to 48-bit coded bits to generate 48 BPSK symbols. The transmitting STA may map 48 BPSK symbols to any location except for a pilot subcarrier (e,g, {subcarrier index −21, −7, +7, +21}) and a DC subcarrier (e.g., {subcarrier index 0}). As a result, 48 BPSK symbols may be mapped to subcarrier indices −26 to −22, −20 to −8, −6 to −1, +1 to +6, +8 to +20, and +22 to +26. The transmitting STA may additionally map the signals of {−1, −1, −1, 1} to the subcarrier index {−28, −27, +27, +28}. The above signal may be used for channel estimation in the frequency domain corresponding to {−28, −27, +27, +28}.
The transmitting STA may construct RL-SIG which is constructed identically to L-SIG. For RL-SIG, BPSK modulation is applied. The receiving STA may recognize that the received PPDU is a HE PPDU or an EHT PPDU based on the existence of the RL-SIG.
After the RL-SIG of
The U-SIG may include N-bit information and may include information for identifying the type of EHT PPDU. For example, U-SIG may be configured based on two symbols (e.g., two consecutive OFDM symbols). Each symbol (e.g., OFDM symbol) for the U-SIG may have a duration of 4 us, and the U-SIG may have a total 8 us duration. Each symbol of the U-SIG may be used to transmit 26 bit information. For example, each symbol of the U-SIG may be transmitted and received based on 52 data tones and 4 pilot tones.
Through the U-SIG (or U-SIG field), for example, A bit information (e.g., 52 un-coded bits) may be transmitted, the first symbol of the U-SIG (e.g., U-SIG-1) may transmit the first X bit information (e.g., 26 un-coded bits) of the total A bit information, and the second symbol of the U-SIG (e.g., U-SIG-2) may transmit the remaining Y-bit information (e.g., 26 un-coded bits) of the total A-bit information. For example, the transmitting STA may obtain 26 un-coded bits included in each U-SIG symbol. The transmitting STA may generate 52-coded bits by performing convolutional encoding (e.g., BCC encoding) based on a rate of R=½, and perform interleaving on the 52-coded bits. The transmitting STA may generate 52 BPSK symbols allocated to each U-SIG symbol by performing BPSK modulation on the interleaved 52-coded bits. One U-SIG symbol may be transmitted based on 56 tones (subcarriers) from subcarrier index −28 to subcarrier index +28, except for DC index 0. The 52 BPSK symbols generated by the transmitting STA may be transmitted based on the remaining tones (subcarriers) excluding pilot tones −21, −7, +7, and +21 tones.
For example, the A bit information (e.g., 52 un-coded bits) transmitted by the U-SIG includes a CRC field (e.g., a 4-bit field) and a tail field (e.g., 6 bit-length field). The CRC field and the tail field may be transmitted through the second symbol of the U-SIG. The CRC field may be constructed based on 26 bits allocated to the first symbol of U-SIG and 16 bits remaining except for the CRC/tail field in the second symbol, and may be constructed based on a conventional CRC calculation algorithm. In addition, the tail field may be used to terminate the trellis of the convolution decoder, and for example, the tail field may be set to 0.
A bit information (e.g., 52 un-coded bits) transmitted by the U-SIG (or U-SIG field) may be divided into version-independent bits and version-independent bits. For example, a size of the version-independent bits may be fixed or variable. For example, the version-independent bits may be allocated only to the first symbol of U-SIG, or the version-independent bits may be allocated to both the first symbol and the second symbol of U-SIG. For example, the version-independent bits and the version-dependent bits may be referred as various names such as a first control bit and a second control bit, etc.
For example, the version-independent bits of the U-SIG may include a 3-bit physical layer version identifier (PHY version identifier). For example, the 3-bit PHY version identifier may include information related to the PHY version of the transmitted/received PPDU. For example, the first value of the 3-bit PHY version identifier may indicate that the transmission/reception PPDU is an EHT PPDU. In other words, when transmitting the EHT PPDU, the transmitting STA may set the 3-bit PHY version identifier to a first value. In other words, the receiving STA may determine that the received PPDU is an EHT PPDU based on the PHY version identifier having the first value.
For example, the version-independent bits of U-SIG may include a 1-bit UL/DL flag field. A first value of the 1-bit UL/DL flag field is related to UL communication, and a second value of the UL/DL flag field is related to DL communication.
For example, the version-independent bits of the U-SIG may include information on the length of a transmission opportunity (TXOP) and information on a BSS color ID.
For example, if the EHT PPDU is classified into various types (e.g., EHT PPDU related to SU mode, EHT PPDU related to MU mode, EHT PPDU related to TB mode, EHT PPDU related to Extended Range transmission, etc.), information on the type of EHT PPDU may be included in the version-dependent bits of the U-SIG.
For example, the U-SIG may include information on 1) a bandwidth field containing information on a bandwidth, 2) a field containing information on a MCS scheme applied to EHT-SIG, 3) an indication field containing information related to whether the DCM technique is applied to the EHT-SIG, 4) a field containing information on the number of symbols used for EHT-SIG, 5) a field containing information on whether EHT-SIG is constructed over all bands, 6) a field containing information on the type of EHT-LTF/STF, and 7) a field indicating the length of EHT-LTF and CP length.
Preamble puncturing may be applied to the PPDU of
For example, for an EHT MU PPDU, information on preamble puncturing may be included in the U-SIG and/or the EHT-SIG. For example, the first field of the U-SIG may include information on the contiguous bandwidth of the PPDU, and the second field of the U-SIG may include information on preamble puncturing applied to the PPDU.
For example, the U-SIG and the EHT-SIG may include information on preamble puncturing based on the following method. If the bandwidth of the PPDU exceeds 80 MHz, the U-SIG may be individually constructed in units of 80 MHz. For example, if the bandwidth of the PPDU is 160 MHz, the PPDU may include a first U-SIG for a first 80 MHz band and a second U-SIG for a second 80 MHz band. In this case, the first field of the first U-SIG includes information on the 160 MHz bandwidth, and the second field of the first U-SIG includes information on preamble puncturing applied to the first 80 MHz band (i.e., information on a preamble puncturing pattern). In addition, the first field of the second U-SIG includes information on a 160 MHz bandwidth, and the second field of the second U-SIG includes information on preamble puncturing applied to a second 80 MHz band (i.e., information on a preamble puncturing pattern). The EHT-SIG following the first U-SIG may include information on preamble puncturing applied to the second 80 MHz band (i.e., information on a preamble puncturing pattern), and the EHT-SIG following the second U-SIG may include information on preamble puncturing applied to the first 80 MHz band (i.e., information on a preamble puncturing pattern).
Additionally or alternatively, the U-SIG and the EHT-SIG may include information on preamble puncturing based on the following method. The U-SIG may include information on preamble puncturing for all bands (i.e., information on a preamble puncturing pattern). That is, EHT-SIG does not include information on preamble puncturing, and only U-SIG may include information on preamble puncturing (ie, information on a preamble puncturing pattern).
U-SIG may be constructed in units of 20 MHz. For example, if an 80 MHz PPDU is constructed, the U-SIG may be duplicated. That is, the same 4 U-SIGs may be included in the 80 MHz PPDU. PPDUs exceeding 80 MHz bandwidth may include different U-SIGs.
The EHT-SIG of
The EHT-SIG may include technical features of HE-SIG-B described through
As in the example of
In the same way as in the example of
As in the example of
A mode in which a common field of EHT-SIG is omitted may be supported. The mode in which the common field of the EHT-SIG is omitted may be referred as a compressed mode. When the compressed mode is used, a plurality of users (i.e., a plurality of receiving STAs) of the EHT PPDU may decode the PPDU (e.g., the data field of the PPDU) based on non-OFDMA. That is, a plurality of users of the EHT PPDU may decode a PPDU (e.g., a data field of the PPDU) received through the same frequency band. When a non-compressed mode is used, multiple users of the EHT PPDU may decode the PPDU (e.g., the data field of the PPDU) based on OFDMA. That is, a plurality of users of the EHT PPDU may receive the PPDU (e.g., the data field of the PPDU) through different frequency bands.
EHT-SIG may be constructed based on various MCS scheme. As described above, information related to the MCS scheme applied to the EHT-SIG may be included in the U-SIG. The EHT-SIG may be constructed based on the DCM scheme. The DCM scheme may reuse the same signal on two subcarriers to provide an effect similar to frequency diversity, reduce interference, and improve coverage. For example, modulation symbols to which the same modulation scheme is applied may be repeatedly mapped on available tones/subcarriers. For example, modulation symbols (e.g., BPSK modulation symbols) to which a specific modulation scheme is applied may be mapped to first contiguous half tones (e.g., 1st to 26th tones) among the N data tones (e.g., 52 data tones) allocated for EHT-SIG, and modulation symbols (e.g., BPSK modulation symbols) to which the same specific modulation scheme is applied may be mapped to the remaining contiguous half tones (e.g., 27th to 52nd tones). That is, a modulation symbol mapped to the 1st tone and a modulation symbol mapped to the 27th tone are the same. As described above, information related to whether the DCM scheme is applied to the EHT-SIG (e.g., a 1-bit field) may be included in the U-SIG. The EHT-STF of
Information on the type of STF and/or LTF (including information on a guard interval (GI) applied to LTF) may be included in the U-SIG field and/or the EHT-SIG field of
The PPDU (i.e., EHT PPDU) of
For example, a EHT PPDU transmitted on a 20 MHz band, that is, a 20 MHz EHT PPDU may be constructed based on the RU of
The EHT PPDU transmitted on the 80 MHz band, that is, the 80 MHz EHT PPDU may be constructed based on the RU of
The tone-plan for 160/240/320 MHz may be configured in the form of repeating the pattern of
The PPDU of
The receiving STA may determine the type of the received PPDU as the EHT PPDU based on the following. For example, when 1) the first symbol after the L-LTF signal of the received PPDU is BPSK, 2) RL-SIG in which the L-SIG of the received PPDU is repeated is detected, and 3) the result of applying the modulo 3 calculation to the value of the Length field of the L-SIG of the received PPDU (i.e., the remainder after dividing by 3) is detected as 0, the received PPDU may be determined as a EHT PPDU. When the received PPDU is determined to be an EHT PPDU, the receiving STA may determine the type of the EHT PPDU based on bit information included in symbols subsequent to the RL-SIG of
For example, the receiving STA may determine the type of the received PPDU as the HE PPDU based on the following. For example, when 1) the first symbol after the L-LTF signal is BPSK, 2) RL-SIG in which L-SIG is repeated is detected, and 3) the result of applying modulo 3 to the length value of L-SIG is detected as 1 or 2, the received PPDU may be determined as a HE PPDU.
For example, the receiving STA may determine the type of the received PPDU as non-HT, HT, and VHT PPDU based on the following. For example, when 1) the first symbol after the L-LTF signal is BPSK and 2) RL-SIG in which L-SIG is repeated is not detected, the received PPDU may be determined as non-HT, HT, and VHT PPDU.
In addition, when the receiving STA detects an RL-SIG in which the L-SIG is repeated in the received PPDU, it may be determined that the received PPDU is a HE PPDU or an EHT PPDU. In this case, if the rate (6 Mbps) check fails, the received PPDU may be determined as a non-HT, HT, or VHT PPDU. If the rate (6 Mbps) check and parity check pass, when the result of applying modulo 3 to the Length value of L-SIG is detected as 0, the received PPDU may be determined as an EHT PPDU, and when the result of Length mod 3 is not 0, it may be determined as a HE PPDU.
The PPDU of
A trigger frame may allocate a resource for at least one TB PPDU transmission and request TB PPDU transmission. A trigger frame may also include other information required by a STA which transmits a TB PPDU in response thereto. A trigger frame may include common information and a user information list field in a frame body.
A common information field may include information commonly applied to at least one TB PPDU transmission requested by a trigger frame, e.g., a trigger type, a UL length, whether a subsequent trigger frame exists (e.g., More TF), whether channel sensing (CS) is required, a UL bandwidth (BW), etc.
A trigger type subfield in a 4-bit size may have a value from 0 to 15. Among them, a value of a trigger type subfield, 0, 1, 2, 3, 4, 5, 6 and 7, is defined as corresponding to basic, Beamforming Report Poll (BFRP), multi user-block acknowledgment request (MU-BAR), multi user-request to send (MU-RTS), Buffer Status Report Poll (BSRP), groupcast with retries (GCR) MU-BAR, Bandwidth Query Report Poll (BQRP) and NDP Feedback Report Poll (NFRP) and a value of 8-15 is defined as being reserved.
Among common information, a trigger dependent common information subfield may include information that is selectively included based on a trigger type.
A special user information field may be included in a trigger frame. A special user information field does not include user-specific information, but includes extended common information which is not provided in a common information field.
A user information list includes at least 0 user information field.
It represents that a AID12 subfield is basically a user information field for a STA having a corresponding AID. In addition, when a AID12 field has a predetermined specific value, it may be utilized for other purpose including allocating a random access (RA)-RU or being configured in a form of a special user information field. A special user information field is a user information field which does not include user-specific information but includes extended common information not provided in a common information field. For example, a special user information field may be identified by an AID12 value of 2007 and a special user information field flag subfield in a common information field may represent whether a special user information field is included.
A RU allocation subfield may represent a size and a position of a RU/a MRU. To this end, a RU allocation subfield may be interpreted with a PS160 (primary/secondary 160 MHz) subfield of a user information field, a UL BW subfield of a common information field, etc.
Additionally, in the present disclosure, a tone plan may be related to a rule for determining the size and/or location of a resource unit (RU). Hereinafter, a tone plan applied to a HE PPDU (i.e., a PPDU according to the IEEE 802.11ax standard) is described as an example. Specifically, the RU size/location applied to the HE PPDU and the control information related to the RU applied to the HE PPDU are described.
In the present disclosure, the control information related to the RU (or the control information related to the tone plan) may include control information onabout the size and location of the RU, information on the user STA allocated to a specific RU, a frequency bandwidth for a PPDU including the RU, and/or a modulation scheme applied to the specific RU. The control information related to the RU may be included in the SIG field. For example, the control information related to the RU may be included in the HE-SIG-B field. That is, in the process of generating a transmission PPDU, the transmitting STA may include control information on the RU included in the PPDU in the HE-SIG-B field. In addition, the receiving STA may receive the HE-SIG-B included in the reception PPDU, obtain the control information included in the HE-SIG-B, determine whether there is an RU allocated to the corresponding receiving STA, and decode the allocated RU based on the HE-SIG-B.
In the existing wireless LAN system (e.g., IEEE 802.11ax standard), HE-STF, HE-LTF, and data fields can be configured in RU units. That is, when the first RU for the first receiving STA is configured, the STF/LTF/data fields for the first receiving STA may be transmitted and received through the first RU.
In an existing wireless LAN system (e.g., IEEE 802.11ax standard), a PPDU for one receiving STA (i.e., SU PPDU) and a PPDU for multiple receiving STAs (i.e., MU PPDU) may be defined separately, and a tone plan for each may be defined separately.
Specifically, the RU may include multiple subcarriers. For example, if the RU includes N subcarriers, it may be expressed as an N-tone RU or N RU. The location of a specific RU may be indicated by a subcarrier index. Here, the subcarrier index may be defined in units of subcarrier frequency spacing. For example, in a wireless LAN system, the subcarrier frequency spacing may be 312.5 kHz or 78.125 kHz, and the subcarrier frequency spacing for the RU may be 78.125 kHz. That is, the subcarrier index “+1” for the RU may mean a location that is increased by 78.125 kHz based on the DC tone, and the subcarrier index “−1” for the RU may mean a location that is decreased by 78.125 kHz based on the DC tone. For example, if the location of a specific RU is represented as [−121:−96], the RU is located in the region from subcarrier index −121 to subcarrier index −96, and as a result, the RU may include 26 subcarriers. In addition, the N-tone RU may include a pre-configured pilot tone.
In existing wireless LAN systems (e.g., systems compatible with the IEEE 802.11ax and IEEE 802.11be standards), various methods have been discussed for efficient use of wideband (e.g., up to 320 MHz) in single-user and/or multi-user transmissions, such as preamble puncturing or multiple RU (MRU) allocation. Here, the MRU allocation method refers to a method of combining multiple RUs and allocating them to a specific STA in order to improve throughput, efficiency, etc.
As mentioned above, in the existing wireless LAN system, RU and MRU used in non-OFDMA/OFDMA transmission up to a bandwidth of up to 320 MHz (e.g., 20 MHz, 40 MHz, 80 MHz, 160 MHz, 320 MHz) are defined. The allocation information for RU/MRU may be transmitted/indicated by being included in the U-SIG related to MU PPDU, or may be transmitted/indicated through RU allocation information in the trigger frame requesting TB PPDU, etc. In particular, in the case of non-OFDMA transmission, restricted RU/MRU may be applied for each bandwidth considering the preamble puncturing situation.
Specifically, as described with reference to
As described above, the U-SIG field may include version-independent fields and version-dependent fields. The version-independent fields may include a 3-bit version identifier indicating the Wi-Fi version of IEEE 802.11be and subsequent standards, a 1-bit DL/UL flag, BSS color, TXOP duration information, etc. The version-dependent fields may include information such as PPDU format type, bandwidth, MCS, etc. The U-SIG field may be jointly encoded with two symbols, and may consist of 52 data tones and 4 pilot tones for each 20 MHz channel. In addition, the U-SIG may be modulated with BPSK ½ code rate, the same as the HE-SIG-A.
In this regard, the puncturing pattern (i.e., RU/MRU pattern) may be indicated through the preamble puncturing related information (e.g., punctured channel information field) in the U-SIG field. Here, the information may be set to the same value in all 20 MHz channels that are not punctured for non-OFDMA transmission.
As described above, EHT-SIG may include common fields and user-specific fields, and may be encoded with variable MCS. Information on spatial streams and RUs may be indicated through the common fields, and information on a specific user or STA, such as information ID, MCS, and coding, may be indicated through the user-specific fields. In addition, EHT-SIG may include different information in units of 80 MHz, and may include two EHT-SIG content channels (e.g., EHT-SIG content channel 1 (CC1) and EHT-SIG CC2) within 80 MHz.
As mentioned above, various sizes of RU/MRU may be defined and used in the IEEE 802.11be standard. For example, 26 tone RU, 52 tone RU, 106 tone RU, 242 tone RU, 484 tone RU, 996 tone RU, etc. may be defined. For example, 26+52 tone MRU, 106+26 tone MRU, 484+242 tone MRU, 996+484 tone MRU, 996+484+242 tone MRU (only for non-OFDMA transmission), 2×996+484 tone MRU, 3×996 tone MRU, 3×996+484 tone MRU, etc. may be defined. Accordingly, an STA compatible with the 11be standard may be allocated one RU/MRU defined as above in OFDMA or non-OFDMA operation, and may perform signal transmission or reception on the allocated one RU/MRU. In the case of a small-sized MRU (i.e., 26+52 tone MRU, or 106+26 tone MRU), the RUs included in one MRU are adjacent to each other in the frequency domain. A large-sized MRU (i.e., 484+242 tone MRU, 996+484 tone MRU, 996+484+242 tone MRU, 2×996+484 tone MRU, 3×996 tone MRU, or 3×996+484 tone MRU) may be applied when some subchannel(s) are punctured, and the RUs included in one MRU are adjacent to each other in the frequency domain except for the punctured subchannels.
In next-generation wireless LAN systems (e.g., IEEE 802.11 be release 2, next Wi-Fi, etc.), bandwidths exceeding the existing wideband (i.e., up to 320 MHz) may be utilized to improve throughput/utility.
Therefore, the present disclosure proposes a method for defining and allocating RU/multiple RU (MRU) in a case where a bandwidth exceeding the wideband of an existing wireless LAN system is defined/applied.
For clarity of explanation, the proposal of the present disclosure is explained below assuming the case of 480 MHz/640 MHz, but may be expanded and applied to various bandwidths that may be utilized in next-generation wireless LAN systems.
For example, bandwidths of 640 MHz and 480 MHz may be defined in a subsequent wireless LAN system to improve throughput. Considering this, various RUs/MRUs need to be defined to efficiently use/utilize the channel even in the corresponding situation/bandwidth.
In this regard, for non-OFDMA transmission in a wider bandwidth, a new RU/MRU applying a preamble puncturing method may be defined. In addition, for OFDMA transmission, in addition to the RU/MRU defined in the existing wireless LAN system (e.g., IEEE 802.11 be), a newly defined RU/MRU for non-OFDMA transmission situations may be defined/utilized.
In the following disclosure, for ease of explanation, some descriptions may be expressed/described only in terms of the size of RU/MRU, excluding the RU/MRU expression.
Additionally, although the present disclosure describes the MRU pattern as a representative example, the pattern according to the proposal of the present disclosure may also be interpreted as an RU pattern that can be utilized in a bandwidth exceeding 320 MHz.
This embodiment is about a new RU/MRU that can be used for non-OFDMA transmission and OFDMA transmission at 640 MHz, when considering 480 MHz as one case of punctured 640 MHz, rather than defining 480 MHz as one separate bandwidth.
First, a RU/MRU for non-OFDMA transmission at 640 MHz is described.
The MRU for non-OFDMA transmission can be configured in various ways, taking into account the preamble puncturing situation, as in the following example.
For example, in the absence of preamble puncturing, 8×996 tone RU/MRU may be defined. Additionally, in the case of considering one or more 80 MHz puncturing, 7×996 tone MRU, 6×996 tone MRU, 5×996 tone MRU, and 4×996 tone MRU may be considered.
That is, as described above, an 80 MHz (sub) channel/bandwidth may correspond to 996 tones, and preamble puncturing in units of 80 MHz channel/bandwidth may mean preamble puncturing in units of 996 tones.
Hereinafter, for clarity of explanation, preamble puncturing in units of X MHz (sub) channel/bandwidth is referred to as X MHz channel puncturing.
Referring to
The 996-tone RUs in
Additionally, 7×996 tone MRU 1 to 8 exemplify cases of 7×996 tone MRUs in which one 80 MHz channel puncturing is performed. That is, in this case, one 996 tone RU may be punctured, and 8 MRUs may be defined depending on the puncturing location.
For example, the MRU illustrated in
Table 1 illustrates 8×996 tone RU/MRU and 7×996 tone MRU available in 640 MHz bandwidth.
Referring to Table 1, the channel size corresponding to each “O” and “X” is 80 MHz, and each channel may be mapped from the lowest 80 MHz to the highest 80 MHz within the 640 MHz bandwidth. Here, “O” represents the non-punctured portion, and “X” represents the punctured portion.
If the expression in Table 1 is extended to the cases of 6×996 tone MRU, 5×996 tone MRU, and 4×996 tone MRU, it may be expressed as shown in Table 2 below.
Table 2 illustrates 8×996 tone RU/MRU, 7×996 tone MRU, 6×996 tone MRU, 5×996 tone MRU, and 4×996 tone MRU available in 640 MHz bandwidth.
Referring to Table 2, considering preamble puncturing for each RU/MRU, various MRU patterns may be defined. One MRU pattern may be defined for 8×996 tone RU/MRU. Eight MRU patterns may be defined for 7×996 tone MRU. 28 MRU patterns may be defined for 6×996 tone MRU. 56 MRU patterns may be defined for 5×996 tone MRU. 70 MRU patterns may be defined for 4×996 tone MRU.
For MRU patterns such as Table 2, there may be a large number of MRU patterns because we consider cases where more than one 80 MHz channel puncturing is performed. In this case, it may be very complicated in terms of scheduling.
For example, the puncturing pattern may be indicated by the puncturing-related information (e.g., Punctured channel information field) in the U-SIG. As the number of puncturing patterns increases, the field size of the corresponding information increases, which may increase signaling overhead and implementation complexity.
Therefore, in order to reduce scheduling overhead and implementation complexity, the available puncturing patterns may be defined with restrictions as in the following example.
For example, considering the case of no 80 MHz channel puncturing, 8×996 tone RU/MRU may be defined. Additionally, considering one 80 MHz channel puncturing, 7×996 tone MRU may be defined.
In this case, 8×996 tone RU/MRU and 7×996 tone MRU may correspond to the pattern in
Additionally, a 6×996 tone MRU may be defined considering one 160 MHz channel puncturing (i.e. puncturing of 2×996 tone units).
Referring to
Additionally, a 5×996 tone MRU may be defined considering one 80 MHz channel puncturing and one 160 MHz channel puncturing.
Referring to
At this time, 80 MHz channel puncturing and 160 MHz channel puncturing may be performed on consecutive RUs (i.e., consecutive 996 tones and 2×996 tones) or on non-consecutive RUs (i.e., non-consecutive 996 tones and 2×996 tones).
Additionally, a 4×996 tone MRU may be defined considering two 160 MHz channel puncturing.
Referring to
At this time, the two 160 MHz channel puncturings may be performed on either consecutive RUs (i.e., two consecutive 2×996 tones) or on non-consecutive RUs (i.e., two non-consecutive 2×996 tones).
Additionally or alternatively, with respect to the 4×996 tone MRU pattern, one 320 MHz channel puncturing may be considered. Here, the 320 MHz channel puncturing may correspond to channel puncturing for four consecutive 996 tones. In this case, two 4×996 tone MRUs may be defined, such as a pattern such as 4×996 tone MRU 1 and a pattern such as 4×996 tone MRU 6 in
In the case of considering the puncturing of the 320 MHz channel, it may be interpreted as a non-OFDMA RU/MRU of 320 MHz, not a non-OFDMA RU/MRU of 640 MHz band. In this regard, 4×996 tone MRU may be defined only on Primary 320 MHz or Secondary 320 MHz. In the existing wireless LAN system, transmission on at least Primary 20 MHz channel is essential, so it may not be allowed to transmit non-OFDMA PPDU only on Secondary 320 MHz excluding Primary channel in actual transmission. In addition, transmission of non-OFDMA PPDU only on Primary 320 may correspond to non-OFDMA PPDU in 320 MHz band. Additionally or alternatively, assuming that transmission is allowed only on the secondary channel, excluding the primary channel, the 320 MHz channel puncturing may also be defined as a non-OFDMA RU/MRU in the 640 MHz band.
Based on the restrictions on available puncturing patterns as described above, 8×996 tone RU/MRU, 7×996 tone MRU, 6×996 tone MRU, 5×996 tone MRU, and 4×996 tone MRU (e.g.,
Table 3 illustrates 8×996 tone RU/MRU, 7×996 tone MRU, 6×996 tone MRU, 5×996 tone MRU, and 4×996 tone MRU considering signaling overhead in 640 MHz bandwidth.
Referring to Table 3, one MRU pattern may be defined for 8×996 tone RU/MRU. Eight MRU patterns may be defined for 7×996 tone MRU. Four MRU patterns may be defined restrictively for 6×996 tone MRU. 24 MRU patterns may be defined restrictively for 5×996 tone MRU. Six and/or two MRU patterns may be defined restrictively for 4×996 tone MRU.
Additionally, for the various RU/MRU patterns described above (e.g., Table 2, Table 3), an additional 40 MHz channel puncturing may be considered. Here, the 40 MHz channel puncturing may correspond to puncturing in 484 tone units.
For example, considering an additional 40 MHz channel puncturing for a particular RU/MRU, 7×996+484 tone MRU, 6×996+484 tone MRU, 5×996+484 tone MRU, and 4×996+484 tone MRU may be defined/utilized.
Here, the 7×996+484 tone MRU may correspond to a RU/MRU configured by puncturing any one 40 MHz channel in an 8×996 tone RU/MRU.
Additionally, a 6×996+484 tone MRU may correspond to a RU/MRU configured by puncturing any one 40 MHz channel in a 7×996 tone MRU.
Additionally, a 5×996+484 tone MRU may correspond to a RU/MRU configured by puncturing any one 40 MHz channel in a 6×996 tone MRU.
Additionally, a 4×996+484 tone MRU may correspond to a RU/MRU configured by puncturing any one 40 MHz channel in a 5×996 tone MRU.
As mentioned above, considering an additional 40 MHz channel puncturing may increase the number of RU/MRU candidates. In addition, using or not using an additional 484 tone RU in a wider bandwidth (e.g., bandwidth greater than 320 MHz) may not significantly affect the throughput. Considering this, the case of considering an additional 40 MHz channel puncturing may be excluded.
Additionally, for 5×996 tone MRU, 5×996+484 tone MRU, and 4×996+484 tone MRU, it may be considered that the lowest or highest 160 MHz channel within the 640 MHz bandwidth is always punctured.
That is, except for one of the 160 MHz channels at both ends, a 480 MHz channel may be formed in which the 320 MHz channel and the 160 MHz channel are located consecutively. Here, various 5×996 tone MRUs may be formed by puncturing one 80 MHz channel, and various 4×996+484 tone MRUs may be formed by puncturing one additional 40 MHz channel. In addition, various 5×996+484 tone MRUs may be formed by puncturing one 40 MHz channel for the 480 MHz channel formed as described above.
Additionally, for 6×996 tone MRU, only two 6×996 tone MRUs may be considered, considering the case where the lowest or highest 160 MHz channel within the 640 MHz bandwidth is always punctured.
If 480 MHz is defined as one bandwidth (i.e., 480 MHz is assumed as an independent bandwidth rather than a case of 640 MHz), among the non-OFDMA RU/MRUs in the previously proposed 640 MHz bandwidth, 5×996 tone MRU, 5×996+484 tone MRU, and 4×996+484 tone MRU may be excluded. In addition, exclusion of 6×996 tone MRU and 4×996 tone MRU may also be considered. In this case, the excluded RU/MRU may be redefined as a non-OFDMA RU/MRU in the 480 MHz bandwidth in the embodiment described below (e.g., embodiment 2).
Additionally or alternatively, a method of applying RU/MRU in 320 MHz non-OFDMA defined in existing wireless LAN systems (e.g., IEEE 802.11 be, etc.) to two 320 MHz channels constituting a 640 MHz channel may also be considered.
A method of defining RU/MRU patterns for a 640 MHz bandwidth based on RU/MRU patterns defined in existing wireless LAN systems may be applied. That is, unlike existing wireless LAN systems, a method of defining RU/MRU patterns for relatively large bandwidths by combining pre-defined RU/MRU patterns for relatively small bandwidths may be considered.
Specifically, RU/MRU in 320 MHz non-OFDMA may be applied independently according to the preamble puncturing pattern within each 320 MHz, and consequently, RU/MRU in 640 MHz non-OFDMA may be configured by a combination of these.
For example, in a existing wireless LAN system, for a 320 MHz bandwidth, 4×996 tone RU/MRU, 3×996 tone RU/MRU, 3×996+484 tone RU/MRU, and 2×996+484 tone RU/MRU are defined based on 80 MHz/40 MHz channel puncturing.
At this time, the RU/MRU in 640 MHz non-OFDMA configured based on the existing RU/MRU defined for the 320 MHz bandwidth is as shown in Table 4 below.
Table 4 illustrates RU/MRU in 640 MHz non-OFDMA according to the existing defined RU/MRU combinations.
Referring to Table 4, {x} means x tone RU/MRU within a 320 MHz channel, and the order is independent of the high and low frequencies. In addition, in each combination, there may be various forms of RU/MRU depending on the preamble puncturing pattern of each channel.
Here, some RUs/MRUs may overlap with the RUs/MRUs proposed in this embodiment.
Additionally or alternatively, considering the case where the lowest or highest 160 MHz channel among 640 MHz is punctured, a method of applying RU/MRU in 320 MHz non-OFDMA and RU/MRU in 160 MHz non-OFDMA defined in existing wireless LAN systems (e.g., IEEE 802.11 be, etc.) to one 320 MHz channel and one 160 MHz channel constituting the remaining 480 MHz channels, respectively, may also be considered.
Specifically, RU/MRU in 320 MHz non-OFDMA and RU/MRU in 160 MHz non-OFDMA may be applied independently according to the preamble puncturing pattern within each 320 MHz and the preamble puncturing pattern within 160 MHz, and as a result, RU/MRU in 640 MHz non-OFDMA may be configured by a combination of these.
For example, in an existing wireless LAN system, for a 160 MHz bandwidth, based on 40 MHz/20 MHz channel puncturing, 2×996 tone RU/MRU, 996+484+242 tone RU/MRU, and 996+484 tone RU/MRU are defined. Additionally, for a 320 MHz bandwidth, based on 80 MHz/40 MHz channel puncturing, 4×996 tone RU/MRU, 3×996 tone RU/MRU, 3×996+484 tone RU/MRU, and 2×996+484 tone RU/MRU are defined.
At this time, the RU/MRU in 640 MHz non-OFDMA configured based on the existing RU/MRU defined for the 320 MHz bandwidth and 160 MHz bandwidth (in case of 160 MHz puncturing at one of the two ends) is as shown in Table 5 below.
Table 5 illustrates RU/MRU in 640 MHz non-OFDMA according to the existing defined RU/MRU combinations.
Referring to Table 5, {x} means x tone RU/MRU within a 320 MHz channel, [y] means y tone RU/MRU within a 160 MHz channel, and the order is independent of the high and low frequencies. In addition, various forms of RU/MRU may exist depending on the preamble puncturing pattern of each channel in each combination.
Here, some RUs/MRUs may overlap with the RUs/MRUs proposed in this embodiment.
If 480 MHz is defined as one bandwidth (i.e., 480 MHz is assumed as an independent bandwidth rather than a case of 640 MHz), the RU/MRU in 640 MHz non-OFDMA formed by the combination of RU/MRU in 320 MHz non-OFDMA and RU/MRU in 160 MHz non-OFDMA may be excluded. In this case, the excluded RU/MRU may be redefined as a non-OFDMA RU/MRU in the 480 MHz bandwidth in the embodiment described below (e.g., embodiment 2).
Additionally, although various RU/MRU candidates are proposed as described above, in actual non-OFDMA transmission, the channel including the primary 20 MHz may not be punctured, and the RU/MRU may be excluded from the non-OFDMA transmission.
Next, a RU/MRU for OFDMA transmission at 640 MHz is described.
In this regard, a method of applying RU/MRU defined in an existing wireless LAN system (e.g., IEEE 802.11 be, etc.) may be considered.
For example, in the case of MRU, combinations may only be possible within a specific channel, as in the existing definition.
Specifically, small MRUs (i.e., 52+26 tone MRUs, 106+26 tone MRUs) may only be defined within a 20 MHz channel, 484+242 tone MRUs may only be defined within an 80 MHz channel, and 996+484 tone MRUs may only be defined within a 160 MHz channel. Additionally, 2×996 tone MRUs may only be defined within a 160 MHz channel, and 2×996+484 tone MRUs, 3×996 tone MRUs, and 3×996+484 tone MRUs may only be defined within a 320 MHz channel.
Additionally, the MRU defined for the non-OFDMA transmission described above in this embodiment may be additionally defined and used for OFDMA transmission. In this regard, 8×996 tone RU/MRU may be excluded, and 4×996 tone MRU may can be defined only within a 320 MHz channel.
If 480 MHz is assumed as an independent bandwidth rather than a case of 640 MHz, Some cases (i.e., some RU/MRU patterns) in non-OFDMA transmission may be excluded, but in OFDMA transmission, such cases may not be excluded and may always be defined. However, the RU/MRU may be applied only within the remaining 480 MHz excluding the first 160 MHz or the last 160 MHz of 640 MHz. That is, the RU/MRU may be independent of puncturing in the first 160 MHz channel or the last 160 MHz channel. Alternatively, the RU/MRU may be applied only within the remaining 480 MHz in a situation where the first 160 MHz channel or the last 160 MHz channel of 640 MHz is punctured.
This embodiment is about a new RU/MRU that may be used for non-OFDMA transmission and OFDMA transmission at 480 MHz, considering the case where 480 MHz is defined as one bandwidth (i.e., 480 MHz is assumed as one independent bandwidth, not one case of 640 MHz).
First, a RU/MRU for non-OFDMA transmission at 480 MHz is described.
The MRU for non-OFDMA transmission may be configured in various ways, taking into account the preamble puncturing situation, as in the following example.
For example, in the absence of preamble puncturing, 6×996 tone RU/MRU may be defined. Additionally, in the case of considering one or more 80 MHz puncturing, 5×996 tone MRU, and 4×996 tone MRU may be considered.
That is, as in the aforementioned embodiment 1, an 80 MHz channel/bandwidth may correspond to 996 tones, and 80 MHz channel preamble puncturing may mean preamble puncturing in units of 996 tones.
Referring to
The 996-tone RUs in
Additionally, 5×996 tone MRU 1 to 6 illustrate cases of 5×996 tone MRUs in which one 80 MHz channel puncturing is performed. That is, in this case, one 996 tone RU may be punctured, and six MRUs may be defined depending on the puncturing location.
Additionally, 4×996 tone MRUs 1 to 15 illustrate cases of 4×996 tone MRUs where two 80 MHz channel puncturings are performed. In this case, the two 80 MHz channel puncturings may be performed on either consecutive RUs (i.e., two consecutive 996 tones) or non-consecutive RUs (i.e., two non-consecutive 996 tones).
For example, the MRU illustrated in
Table 6 illustrates 6×996 tone RU/MRU, 5×996 tone MRU, and 4×996 tone MRU available in 480 MHz bandwidth.
Referring to Table 6, the channel size corresponding to each “O” and “X” is 80 MHz, and each channel may be mapped from the lowest 80 MHz to the highest 80 MHz within the 480 MHz bandwidth. Here, “O” represents the non-punctured portion, and “X” represents the punctured portion.
Referring to Table 6, considering preamble puncturing for each RU/MRU, various MRU patterns may be defined. One MRU pattern may be defined for 6×996 tone RU/MRU. Six MRU patterns may be defined for 5×996 tone MRU. Fifteen MRU patterns may be defined for 4×996 tone MRU.
For MRU patterns such as Table 6, since it is considered that more than one 80 MHz channel puncturing is performed, there may be a large number of MRU patterns. In this case, it may be very complicated in terms of scheduling.
Therefore, similar to the aforementioned embodiment 1, in order to reduce scheduling overhead and implementation complexity, the available puncturing patterns may be defined with restrictions as in the following example.
Referring to
Additionally, considering one 80 MHz channel puncturing, six 5×996 tone MRUs may be defined according to the puncturing location.
Additionally, considering one 160 MHz channel puncturing, three 4×996 tone MRUs may be defined according to the puncturing position. That is, unlike in
Additionally or alternatively, a 2×996 tone MRU considering one 320 MHz channel puncturing may be considered. Here, the 320 MHz channel puncturing may correspond to channel puncturing for four consecutive 996 tones.
If 480 MHz is composed of 160 MHz in a relatively low frequency region and 320 MHz in a relatively high frequency region, then the corresponding 2×996 tone MRU may correspond to an MRU in which four consecutive 996 tones corresponding to 320 MHz are punctured, and the first two consecutive 996 tones at 480 MHz are punctured. On the other hand, if 480 MHz is composed of 320 MHz in a relatively low frequency region and 160 MHz in a relatively high frequency region, then the corresponding 2×996 tone MRU may correspond to an MRU in which four consecutive 996 tones corresponding to 320 MHz are punctured, and the last two consecutive 996 tones at 480 MHz are punctured.
In the case of considering the puncturing of the 320 MHz channel, it may be interpreted as a non-OFDMA RU/MRU of 160 MHz, not a non-OFDMA RU/MRU of 480 MHz band. In this regard, 2×996 tone MRU may be defined only on Primary 160 MHz or Secondary 160 MHz. In the existing wireless LAN system, transmission on at least Primary 20 MHz channel is essential, so it may not be allowed to transmit a non-OFDMA PPDU only on Secondary 160 MHz, excluding the Primary channel, in actual transmission. In addition, a non-OFDMA PPDU only on Primary 160 may correspond to a non-OFDMA PPDU in the 160 MHz band. Additionally or alternatively, assuming that transmission is allowed only on the secondary channel, excluding the primary channel, the 320 MHz channel puncturing may also be defined as a non-OFDMA RU/MRU in the 480 MHz band.
Based on the restrictions on available puncturing patterns as described above, 6×996 tone RU/MRU, 5×996 tone MRU, and 4×996 tone MRU (e.g.,
Table 7 illustrates 6×996 tone RU/MRU, 5×996 tone MRU, and 4×996 tone MRU considering signaling overhead in 480 MHz bandwidth.
Referring to Table 7, one MRU pattern may be defined for 6×996 tone RU/MRU. Six MRU patterns may be defined for 5×996 tone MRU. Three and/or two MRU patterns may be limitedly defined for 4×996 tone MRU.
Additionally, for the various RU/MRU patterns described above (e.g., Table 6, Table 7), an additional 40 MHz channel puncturing may be considered. Here, the 40 MHz channel puncturing may correspond to puncturing in 484 tone units.
For example, considering one additional 40 MHz channel puncturing for a particular RU/MRU, 5×996+484 tone MRU, and 4×996+484 tone MRU may be defined/utilized.
Here, a 5×996+484 tone MRU may correspond to a RU/MRU configured by puncturing any one 40 MHz channel in a 6×996 tone RU/MRU.
Additionally, a 4×996+484 tone MRU may correspond to a RU/MRU configured by puncturing any one 40 MHz channel in a 5×996 tone MRU.
As mentioned above, considering an additional 40 MHz channel puncturing may increase the number of RU/MRU candidates. Also, using or not using an additional 484 tone RU in a wider bandwidth (e.g., bandwidth greater than 320 MHz) may not significantly affect the throughput. Considering this, the case of considering an additional 40 MHz channel puncturing may be excluded.
Additionally or alternatively, a method of applying RU/MRU in 320 MHz non-OFDMA and RU/MRU in 160 MHz non-OFDMA defined in existing wireless LAN systems (e.g., IEEE 802.11 be, etc.) to one 320 MHz channel and one 160 MHz channel constituting a 480 MHz channel, respectively, may also be considered.
That is, unlike in existing wireless LAN systems, a method of defining an RU/MRU pattern for a relatively large bandwidth by combining pre-defined RU/MRU patterns for relatively small bandwidths may be considered.
Specifically, RU/MRU in 320 MHz non-OFDMA and RU/MRU in 160 MHz non-OFDMA may be applied independently according to the preamble puncturing pattern within each 320 MHz and the preamble puncturing pattern within 160 MHz, and as a result, RU/MRU in 480 MHz non-OFDMA may be configured by a combination of these.
For example, in an existing wireless LAN system, for a 160 MHz bandwidth, based on 40 MHz/20 MHz channel puncturing, 2×996 tone RU/MRU, 996+484+242 tone RU/MRU, and 996+484 tone RU/MRU are defined. Additionally, for a 320 MHz bandwidth, based on 80 MHz/40 MHz channel puncturing, 4×996 tone RU/MRU, 3×996 tone RU/MRU, 3×996+484 tone RU/MRU, and 2×996+484 tone RU/MRU are defined.
At this time, the RU/MRU in 480 MHz non-OFDMA configured based on the existing RU/MRU defined for the 320 MHz bandwidth and 160 MHz bandwidth is as shown in Table 8 below.
Table 8 illustrates RU/MRU in 480 MHz non-OFDMA according to the existing defined RU/MRU combinations.
Referring to Table 8, {x} means x tone RU/MRU within a 320 MHz channel, [y] means y tone RU/MRU within a 160 MHz channel, and the order is independent of the high and low frequencies. In addition, various forms of RU/MRU may exist depending on the preamble puncturing pattern of each channel in each combination.
Here, some RUs/MRUs may overlap with the RUs/MRUs proposed in this embodiment.
Additionally, although various RU/MRU cases/candidates are proposed as mentioned above, in actual non-OFDMA transmission, the channel containing the primary 20 MHz cannot be punctured, and the RU/MRU may be excluded from the non-OFDMA transmission.
Next, a RU/MRU for OFDMA transmission at 480 MHz is described.
In this regard, a method of applying RU/MRU defined in an existing wireless LAN system (e.g., IEEE 802.11 be, etc.) may be considered.
For example, in the case of MRU, combinations may only be possible within a specific channel, as in the existing definition.
Specifically, small MRUs (i.e., 52+26 tone MRUs, 106+26 tone MRUs) may only be defined within a 20 MHz channel, 484+242 tone MRUs may only be defined within an 80 MHz channel, and 996+484 tone MRUs may only be defined within a 160 MHz channel. Additionally, 2×996 tone MRUs may only be defined within a 160 MHz channel, and 2×996+484 tone MRUs, 3×996 tone MRUs, and 3×996+484 tone MRUs may only be defined within a 320 MHz channel.
Additionally, the MRU defined for the non-OFDMA transmission described above in this embodiment may be additionally defined and used for OFDMA transmission. In this regard, 6×996 tone RU/MRU can be excluded, and 4×996 tone MRU may be defined only within a 320 MHz channel.
In step S2110, the STA may receive a physical layer protocol data unit (PPDU) including a SIG field for resource unit allocation related information from another STA.
For example, the resource unit allocation information may be information related to preamble puncturing, and the information may be indicated through the U-SIG field in the (MU) PPDU.
In this regard, the resource unit allocation related information may indicate a specific candidate within a set including a pre-defined number of multiple RU (MRU) candidates for a bandwidth exceeding 320 MHz.
For example, if the bandwidth exceeding 320 MHz corresponds to a 480 MHz bandwidth, the pre-defined number of MRU candidates may include at least one of a first MRU without 80 MHz channel puncturing (e.g., 6×996 tone RU/MRU), a second MRU with one 80 MHz channel puncturing applied (e.g., 5×996 tone MRU), and a third MRU with one 160 MHz channel puncturing applied (e.g., 4×996 tone MRU).
For example, the first MRU may consist of six consecutive 996-tone RUs. Additionally or alternatively, the pre-defined number of MRU candidates may further include one or more fourth MRUs configured by applying 40 MHz channel puncturing corresponding to 484-tone RUs to the first MRU. Here, the size of the one or more fourth MRUs may correspond to 5×996+484 tones.
For example, the second MRU may consist of five 996-tone RUs. The second MRU may be distinguished as one or more second MRU candidates by applying the 80 MHz channel puncturing corresponding to 996-tone RUs to the six 996-tone RUs included in the 480 MHz bandwidth. Additionally or alternatively, the pre-defined number of MRU candidates may further include one or more fifth MRUs configured by applying the 40 MHz channel puncturing corresponding to 484-tone RUs to the one or more second MRU candidates. Here, the size of the one or more fifth MRUs may correspond to 4×996+484 tones.
For example, the third MRU may consist of four 996-tone RUs. The second MRU may be distinguished as one or more third MRU candidates by applying the 160 MHz channel puncturing corresponding to 2×996-tone RUs for the six 996-tone RUs included in the 480 MHz bandwidth.
Additionally or alternatively, if the bandwidth exceeding the 320 MHz corresponds to a 480 MHz bandwidth, the 480 MHz bandwidth may include a 320 MHz channel and a 160 MHz channel. In this regard, the pre-defined number of MRU candidates may consist of a combination of the pre-defined MRU candidates at 320 MHz and the pre-defined MRU candidates at 160 MHz. Here, the size of the pre-defined MRU candidates at 320 MHz may correspond to one or more of 4×996 tones, 3×996 tones, 3×996+484 tones, or 2×996+484 tones. The size of the pre-defined MRU candidates at 160 MHz may correspond to one or more of 2×996 tones, 996+484+242 tones, or 996+484 tones.
Additionally or alternatively, the pre-defined number of MRU candidates may be associated with non-OFDMA transmissions in the 480 MHz bandwidth.
In step S2120, the STA may obtain a data field within the PPDU based on the resource unit allocation related information.
For example, a STA may receive all or part of a PPDU transmitted by another STA. For example, the received signal/field/sequence may have a form as in
The STA may perform decoding of all/part of PPDU. In addition, the STA may obtain control information on tone plan (or RU related information) from decoded PPDU. For example, the another STA may decode L-SIG/RL-SIG/U-SIG/EHT-SIG of PPDU based on L-STF/L-LTF and obtain information included therein. Various RU allocation related information (or information on tone plan) of the present disclosure may be included in U-SIG/EHT-SIG, and the STA may obtain tone plan (or RU related information) by decoding U-SIG/EHT-SIG.
The STA may decode the remaining part of the PPDU based on the acquired tone plan (or RU-related information). For example, the STA may perform automatic gain control (AGC)/channel estimation through the STF/LTF (e.g., EHT-STF/EHT-LTF) field of the PPDU based on information on one plan (or RU). In addition, the STA may decode the data field of the PPDU based on the tone plan (or RU-related information) and obtain the MPDU included in the data field.
In addition, the STA may forward the decoded data to the higher layer (e.g., MAC layer). If the generation of a signal is instructed from the higher layer to the PHY layer in response to the data forwarded to the higher layer, subsequent operations may be performed.
In step S2210, the STA may configure a SIG field for resource unit allocation related information.
The description of information related to resource unit allocation is the same as that described with reference to
In step S2220, the STA may transmit a physical layer protocol data unit (PPDU) including the SIG field to another STA.
For example, the STA may obtain information on the tone plan. Information on the tone plan may include RU size, RU location, control information related to the RU, frequency unit/frequency band that the RU is included in, information on the STA that receives the RU, etc
The STA may construct/generate a PPDU based on the obtained control information. The step of constructing/generating the PPDU may include a step of constructing/generating each field of the PPDU. For example, the STA may construct a SIG (e.g., U-SIG/EHT-SIG) including control information for a tone plan. The STA may construct a field including control information (e.g., N bitmap) indicating the size/location of the RU, and/or a field including an identifier (e.g., AID) of the STA receiving the RU. In addition, the STA may generate an STF/LTF sequence transmitted through a specific RU. The STF/LTF sequence may be generated based on a pre-configured STF generation sequence/LTF generation sequence. In addition, the STA may generate a data field (i.e., MPDU) transmitted through a specific RU.
The STA may transmit the PPDU configured in this manner to another STA. The STA may perform operations such as CSD (cyclic shift diversity), spatial mapping, IDFT (inverse discrete Fourier transform)/IFFT (inverse Fast Fourier transform) operation, GI (guard interval) insertion, etc. The signal/field/sequence configured in this manner may be transmitted in a form such as
Although the examples described above in
The STA in the aforementioned
Embodiments described above are that elements and features of the present disclosure are combined in a predetermined form. Each element or feature should be considered to be optional unless otherwise explicitly mentioned. Each element or feature may be implemented in a form that it is not combined with other element or feature. In addition, an embodiment of the present disclosure may include combining a part of elements and/or features. An order of operations described in embodiments of the present disclosure may be changed. Some elements or features of one embodiment may be included in other embodiment or may be substituted with a corresponding element or a feature of other embodiment. It is clear that an embodiment may include combining claims without an explicit dependency relationship in claims or may be included as a new claim by amendment after application.
It is clear to a person skilled in the pertinent art that the present disclosure may be implemented in other specific form in a scope not going beyond an essential feature of the present disclosure. Accordingly, the above-described detailed description should not be restrictively construed in every aspect and should be considered to be illustrative. A scope of the present disclosure should be determined by reasonable construction of an attached claim and all changes within an equivalent scope of the present disclosure are included in a scope of the present disclosure.
A scope of the present disclosure includes software or machine-executable commands (e.g., an operating system, an application, a firmware, a program, etc.) which execute an operation according to a method of various embodiments in a device or a computer and a non-transitory computer-readable medium that such a software or a command, etc. are stored and are executable in a device or a computer. A command which may be used to program a processing system performing a feature described in the present disclosure may be stored in a storage medium or a computer-readable storage medium and a feature described in the present disclosure may be implemented by using a computer program product including such a storage medium. A storage medium may include a high-speed random-access memory such as DRAM, SRAM, DDR RAM or other random-access solid state memory device, but it is not limited thereto, and it may include a nonvolatile memory such as one or more magnetic disk storage devices, optical disk storage devices, flash memory devices or other nonvolatile solid state storage devices. A memory optionally includes one or more storage devices positioned remotely from processor(s). A memory or alternatively, nonvolatile memory device(s) in a memory include a non-transitory computer-readable storage medium. A feature described in the present disclosure may be stored in any one of machine-readable mediums to control a hardware of a processing system and may be integrated into a software and/or a firmware which allows a processing system to interact with other mechanism utilizing a result from an embodiment of the present disclosure. Such a software or a firmware may include an application code, a device driver, an operating system and an execution environment/container, but it is not limited thereto.
A method proposed by the present disclosure is mainly described based on an example applied to an IEEE 802.11-based system, 5G system, but may be applied to various WLAN or wireless communication systems other than the IEEE 802.11-based system.
| Number | Date | Country | Kind |
|---|---|---|---|
| 10-2022-0041313 | Apr 2022 | KR | national |
This application is the National Stage filing under 35 U.S.C. 371 of International Application No. PCT/KR2023/004149, filed on Mar. 29, 2023, which claims the benefit of earlier filing date and right of priority to Korean Application No. 10-2022-0041313, filed on Apr. 1, 2022, the contents of which are all incorporated by reference herein in their entirety.
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/KR2023/004149 | 3/29/2023 | WO |