WO2020091412A1 - Procédé et dispositif destinés à réaliser une transmission conjointe dans un système lan sans fil - Google Patents

Procédé et dispositif destinés à réaliser une transmission conjointe dans un système lan sans fil Download PDF

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Publication number
WO2020091412A1
WO2020091412A1 PCT/KR2019/014454 KR2019014454W WO2020091412A1 WO 2020091412 A1 WO2020091412 A1 WO 2020091412A1 KR 2019014454 W KR2019014454 W KR 2019014454W WO 2020091412 A1 WO2020091412 A1 WO 2020091412A1
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Prior art keywords
sta
joint transmission
aps
information
frame
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PCT/KR2019/014454
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English (en)
Korean (ko)
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박성진
김정기
박은성
최진수
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엘지전자 주식회사
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Publication of WO2020091412A1 publication Critical patent/WO2020091412A1/fr

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    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B7/00—Radio transmission systems, i.e. using radiation field
    • H04B7/02—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas
    • H04B7/022—Site diversity; Macro-diversity
    • H04B7/024—Co-operative use of antennas of several sites, e.g. in co-ordinated multipoint or co-operative multiple-input multiple-output [MIMO] systems
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B7/00—Radio transmission systems, i.e. using radiation field
    • H04B7/02—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas
    • H04B7/04—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas
    • H04B7/0413—MIMO systems
    • H04B7/0452—Multi-user MIMO systems
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B7/00—Radio transmission systems, i.e. using radiation field
    • H04B7/02—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas
    • H04B7/04—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas
    • H04B7/06—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas at the transmitting station
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L1/00—Arrangements for detecting or preventing errors in the information received
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L1/00—Arrangements for detecting or preventing errors in the information received
    • H04L1/12—Arrangements for detecting or preventing errors in the information received by using return channel
    • H04L1/16—Arrangements for detecting or preventing errors in the information received by using return channel in which the return channel carries supervisory signals, e.g. repetition request signals
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W16/00—Network planning, e.g. coverage or traffic planning tools; Network deployment, e.g. resource partitioning or cells structures
    • H04W16/24—Cell structures
    • H04W16/28—Cell structures using beam steering
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W56/00—Synchronisation arrangements
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W84/00—Network topologies
    • H04W84/02—Hierarchically pre-organised networks, e.g. paging networks, cellular networks, WLAN [Wireless Local Area Network] or WLL [Wireless Local Loop]
    • H04W84/10—Small scale networks; Flat hierarchical networks
    • H04W84/12—WLAN [Wireless Local Area Networks]
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W84/00—Network topologies
    • H04W84/18—Self-organising networks, e.g. ad-hoc networks or sensor networks
    • H04W84/20—Master-slave selection or change arrangements
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W88/00—Devices specially adapted for wireless communication networks, e.g. terminals, base stations or access point devices
    • H04W88/08—Access point devices

Definitions

  • the present specification relates to a technique for performing joint transmission in a wireless LAN system, and more specifically, a method and apparatus for performing joint transmission by selecting an S-AP and performing a sounding procedure by an M-AP in a wireless LAN system It is about.
  • the wireless local area network has been improved in various ways.
  • the IEEE 802.11ax standard proposed an improved communication environment using orthogonal frequency division multiple access (OFDMA) and downlink multi-user multiple input (MIMO) techniques.
  • OFDMA orthogonal frequency division multiple access
  • MIMO downlink multi-user multiple input
  • the new communication standard may be an recently discussed extreme high throughput (EHT) standard.
  • EHT extreme high throughput
  • the EHT standard can use newly proposed increased bandwidth, improved PHY layer protocol data unit (PPDU) structure, improved sequence, and hybrid automatic repeat request (HARQ) technique.
  • PPDU PHY layer protocol data unit
  • HARQ hybrid automatic repeat request
  • the EHT standard may be referred to as the IEEE 802.11be standard.
  • an increased number of spatial streams can be used.
  • the signaling technique in the WLAN system may need to be improved.
  • This specification proposes a method and apparatus for performing joint transmission in a wireless LAN system.
  • An example of the present specification proposes a method for performing joint transmission.
  • the next-generation wireless LAN system is a wireless LAN system (EHT or 802.11be) that improves the 802.11ax system and may satisfy backward compatibility with the 802.11ax system.
  • EHT or 802.11be wireless LAN system
  • This embodiment is performed by a transmitting STA, and the transmitting STA may correspond to an M-AP.
  • the receiving STA of this embodiment is an STA supporting an EHT (Extremely High Throughput) WLAN system, and is received by the first S-AP, second S-AP, or third S-AP through a joint transmission to a STA that receives data. You can respond.
  • EHT Extremely High Throughput
  • the master-access point selects first to third slave-access points (S-APs) to participate in the joint transmission.
  • the M-AP manages a link with the first to third S-APs to share the first information between the first to third S-APs.
  • the M-AP performs the joint transmission to a STA (station) through the first to third S-APs based on the first information.
  • an S-AP suitable for joint transmission is selected by performing a sounding procedure according to a multi-AP coordination scheme, preventing interference from an OBSS STA or an unintended STA, and efficiently performing joint transmission. Can be done with
  • FIG. 1 shows an example of a transmitting device and / or a receiving device of the present specification.
  • WLAN wireless LAN
  • 3 is a diagram for explaining a general link setup process.
  • FIG. 4 is a diagram showing an example of a PPDU used in the IEEE standard.
  • FIG. 5 is a diagram showing the arrangement of a resource unit (RU) used on a 20MHz band.
  • RU resource unit
  • FIG. 6 is a view showing the arrangement of a resource unit (RU) used on the 40MHz band.
  • RU resource unit
  • FIG. 7 is a view showing the arrangement of a resource unit (RU) used on the 80MHz band.
  • RU resource unit
  • FIG. 11 shows an example of a trigger frame.
  • FIG. 13 shows an example of a sub-field included in a per user information field.
  • 16 shows an example of a channel used / supported / defined within a 5 GHz band.
  • FIG. 17 shows an example of a channel used / supported / defined within a 6 GHz band.
  • 20 is a diagram illustrating multiple AP adjustment.
  • 21 shows an example of a null steering operation for avoiding interference.
  • 22 shows an example in which AP coordination and interference are controlled.
  • 25 is a view for explaining C-OFDMA.
  • 26 shows an example of the joint transmission.
  • 27 shows an example of performing joint transmission through M-AP and S-AP.
  • 29 shows an example of joint transmission when direct transmission / reception between M-AP and STA is possible.
  • 31 is a flowchart illustrating a procedure for performing joint transmission in a transmitting STA according to the present embodiment.
  • 32 is a flowchart illustrating a procedure for receiving data through joint transmission in a receiving STA according to the present embodiment.
  • control information EHT-Signal
  • EHT-Signal EHT-Signal
  • EHT-signal EHT-signal
  • the following example of the present specification can be applied to various wireless communication systems.
  • the following example of the present specification may be applied to a wireless local area network (WLAN) system.
  • WLAN wireless local area network
  • this specification may be applied to the IEEE 802.11a / g / n / ac standard, or the IEEE 802.11ax standard.
  • the present specification can be applied to the newly proposed EHT standard or IEEE 802.11be standard.
  • an example of the present specification may be applied to a new wireless LAN standard that improves the EHT standard or IEEE 802.11be.
  • FIG. 1 shows an example of a transmitting device and / or a receiving device of the present specification.
  • STA includes two stations (STA).
  • STA (110, 120) is a mobile terminal (mobile terminal), a wireless device (wireless device), a wireless transmit / receive unit (WTRU), user equipment (User Equipment; UE), mobile station (Mobile Station; MS) , It can also be called various names such as a mobile subscriber unit or simply a user.
  • the STAs 110 and 120 may be called various names such as a receiving device, a transmitting device, a receiving STA, a transmitting STA, a receiving device, and a transmitting device.
  • the STAs 110 and 120 may perform an access point (AP) role or a non-AP role. That is, the STAs 110 and 120 of the present specification may perform functions of an AP and / or a non-AP.
  • AP access point
  • non-AP non-AP
  • the STAs 110 and 120 of the present specification may support various communication standards other than the IEEE 802.11 standard. For example, it may support a communication standard (eg, LTE, LTE-A, 5G NR standard) according to the 3GPP standard. Also, the STA of the present specification may be implemented with various devices such as a mobile phone, a vehicle, and a personal computer.
  • a communication standard eg, LTE, LTE-A, 5G NR standard
  • 3GPP 3rd Generation
  • the STA of the present specification may be implemented with various devices such as a mobile phone, a vehicle, and a personal computer.
  • the STAs 110 and 120 may include a medium access control (MAC) compliant with the IEEE 802.11 standard and a physical layer interface to a wireless medium.
  • MAC medium access control
  • the first STA 110 may include a processor 111, a memory 112, and a transceiver 113.
  • the illustrated processor, memory, and transceiver may each be implemented as separate chips, or at least two or more blocks / functions may be implemented through one chip.
  • the transceiver 113 of the first STA performs a signal transmission / reception operation.
  • an IEEE 802.11 packet eg, IEEE 802.11a / b / g / n / ac / ax / be, etc.
  • the first STA 110 may perform an intended operation of the AP.
  • the processor 111 of the AP may receive a signal through the transceiver 113, process the received signal, generate a transmission signal, and perform control for signal transmission.
  • the memory 112 of the AP may store a signal (ie, a received signal) received through the transceiver 113 and may store a signal (ie, a transmitted signal) to be transmitted through the transceiver.
  • the second STA 120 may perform an intended operation of the Non-AP STA.
  • the non-AP transceiver 123 performs a signal transmission / reception operation.
  • an IEEE 802.11 packet eg, IEEE 802.11a / b / g / n / ac / ax / be, etc.
  • an IEEE 802.11 packet can be transmitted and received.
  • the processor 121 of the Non-AP STA may receive a signal through the transceiver 123, process the received signal, generate a transmission signal, and perform control for signal transmission.
  • the memory 122 of the non-AP STA may store a signal (ie, a received signal) received through the transceiver 123 and may store a signal (ie, a transmitted signal) to be transmitted through the transceiver.
  • the operation of the device indicated as the AP in the following specification may be performed in the first STA 110.
  • the operation of the device indicated by the AP is controlled by the processor 111 of the first STA 110, and a related signal is transmitted or received through the transceiver 113 controlled by the processor 111 of the first STA 110.
  • control information related to the operation of the AP or the transmission / reception signal of the AP may be stored in the memory 112 of the first STA 110.
  • the operation of the device indicated as non-AP in the following specification may be performed in the second STA 120.
  • the operation of the device marked as non-AP is controlled by the processor 121 of the second STA 120, and a related signal is transmitted through the transceiver 123 controlled by the processor 121 of the second STA 120. Or it can be received.
  • control information related to the operation of the non-AP or an AP transmission / reception signal may be stored in the memory 212 of the second STA 120.
  • WLAN wireless LAN
  • FIG. 2 shows the structure of an infrastructure basic service set (BSS) of the Institute of Electrical and Electronic Engineers (IEEE) 802.11.
  • BSS infrastructure basic service set
  • IEEE Institute of Electrical and Electronic Engineers
  • the wireless LAN system may include one or more infrastructure BSSs 200 and 205 (hereinafter, BSS).
  • BSSs 200 and 205 are a set of APs and STAs such as an access point (AP) and STA1 (Station, 200-1) that can successfully communicate with each other by synchronizing, and are not a concept indicating a specific area.
  • the BSS 205 may include one or more combineable STAs 205-1 and 205-2 in one AP 230.
  • the BSS may include at least one STA, APs 225 and 230 providing a distributed service, and a distributed system (DS, 210) connecting multiple APs.
  • DS distributed system
  • the distributed system 210 may connect multiple BSSs 200 and 205 to implement an extended service set (ESS) 240.
  • ESS 240 may be used as a term indicating one network formed by connecting one or several APs through the distributed system 210.
  • APs included in one ESS 240 may have the same service set identification (SSID).
  • the portal may serve as a bridge that performs a connection between a wireless LAN network (IEEE 802.11) and another network (eg, 802.X).
  • IEEE 802.11 IEEE 802.11
  • 802.X another network
  • a network between APs 225 and 230 and a network between APs 225 and 230 and STAs 200-1, 205-1 and 205-2 may be implemented.
  • a network that establishes a network even among STAs without APs 225 and 230 to perform communication is defined as an ad-hoc network or an independent basic service set (BSS).
  • FIG. 2 is a conceptual diagram showing IBSS.
  • IBSS is a BSS operating in an ad-hoc mode. Since IBSS does not include an AP, there is no centralized management entity. That is, STAs 250-1, 250-2, 250-3, 255-4, and 255-5 in IBSS are managed in a distributed manner. In IBSS, all STAs (250-1, 250-2, 250-3, 255-4, 255-5) can be made of mobile STAs, and access to a distributed system is not allowed, so a self-contained network (self-contained) network).
  • 3 is a diagram for explaining a general link setup process.
  • 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 is necessary to find a network that can participate.
  • the STA must identify a compatible network before joining a wireless network, and the network identification process existing in a specific area is called scanning.
  • the scanning methods include active scanning and passive scanning.
  • the STA performing scanning transmits a probe request frame and waits for a response to search for which AP is present while moving channels.
  • the responder transmits a probe response frame to the STA that has transmitted the probe request frame in response to the probe request frame.
  • the responder may be the STA that last transmitted a beacon frame from the BSS of the channel being scanned.
  • the AP since the AP transmits a beacon frame, the AP becomes a responder, and in the IBSS, STAs in the IBSS rotate and transmit a beacon frame, so the responder is not constant.
  • an STA that transmits a probe request frame on channel 1 and receives a probe response frame on channel 1 stores BSS-related information included in the received probe response frame and stores the next channel (for example, number 2).
  • Channel to perform scanning (ie, probe request / response transmission / reception on channel 2) in the same way.
  • the scanning operation may be performed by a passive scanning method.
  • An STA performing scanning based on passive scanning may wait for a beacon frame while moving channels.
  • the beacon frame is one of the management frames in IEEE 802.11, and is periodically transmitted to inform the presence of the wireless network and allow STAs performing scanning to find the wireless network and participate in the wireless network.
  • the AP serves to periodically transmit the beacon frame
  • STAs in the IBSS rotate and transmit the beacon frame.
  • the STA performing scanning stores information on the BSS included in the beacon frame and records beacon frame information in each channel while moving to another channel.
  • the STA receiving the beacon frame may store BSS-related information included in the received beacon frame and move to the next channel to perform scanning in the next channel in the same manner.
  • the STA discovering the network may perform an authentication process through step SS320.
  • Such an authentication process may be referred to as a first authentication process in order to clearly distinguish the security setup operation of step S340, which will be described later.
  • the authentication process of S320 may include a process in which the STA transmits an authentication request frame to the AP, and in response, the AP sends an authentication response frame to the STA.
  • the authentication frame used for authentication request / response corresponds to a management frame.
  • the authentication frame includes authentication algorithm number, authentication transaction sequence number, status code, challenge text, robust security network (RSN), and finite cycle group (Finite Cyclic). Group).
  • the STA may transmit an authentication request frame to the AP.
  • the AP may determine whether to allow authentication for the corresponding STA based on the information included in the received authentication request frame.
  • the AP may provide the result of the authentication process to the STA through the authentication response frame.
  • the successfully authenticated STA may perform a connection process based on step S330.
  • the connection 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.
  • the connection request frame includes information related to various capabilities, beacon listening interval, service set identifier (SSID), supported rates, supported channels, RSN, and mobility domain. , Supported operating classes, TIM broadcast request, and information on interworking service capabilities.
  • the connection response frame includes information related to various capabilities, status codes, association ID (AID), support rate, enhanced distributed channel access (EDCA) parameter set, received channel power indicator (RCPI), and received signal to noise (RSNI). Indicator), mobility domain, timeout interval (association comeback time (association comeback time)), overlapping (overlapping) BSS scan parameters, TIM broadcast response, QoS map, and the like information may be included.
  • step S340 the STA may perform a security setup process.
  • the security setup process of step S340 may include, for example, a process of performing private key setup through 4-way handshaking through an Extensible Authentication Protocol over LAN (EAPOL) frame. .
  • EAPOL Extensible Authentication Protocol over LAN
  • FIG. 4 is a diagram showing an example of a PPDU used in the IEEE standard.
  • PHY protocol data units As illustrated, various types of PHY protocol data units (PPDUs) have been used in standards such as IEEE a / g / n / ac. Specifically, the LTF and STF fields included training signals, and SIG-A and SIG-B included control information for the receiving station, and the data fields contained user data corresponding to PSDU (MAC PDU / Aggregated MAC PDU). Was included.
  • PPDUs PHY protocol data units
  • the HE PPDU according to FIG. 4 is an example of a PPDU for multiple users, and the HE-SIG-B is included only for multiple users, and the corresponding HE-SIG-B may be omitted in the PPDU for a single user.
  • HE-PPDU for multiple users is a legacy-short training field (L-STF), legacy-long training field (L-LTF), legacy-signal (L-SIG), High efficiency-signal A (HE-SIG-A), high efficiency-signal-B (HE-SIG-B), high efficiency-short training field (HE-STF), high efficiency-long training field (HE-LTF) , Data field (or MAC payload) and PE (Packet Extension) field.
  • L-STF legacy-short training field
  • L-LTF legacy-long training field
  • L-SIG legacy-signal
  • HE-SIG-A High efficiency-signal A
  • HE-SIG-B high efficiency-short training field
  • HE-LTF high efficiency-long training field
  • PE Packet Extension
  • the resource unit may include a plurality of subcarriers (or tones).
  • the resource unit may be used when transmitting signals to multiple STAs based on the OFDMA technique.
  • a resource unit may be defined when transmitting a signal to one STA.
  • Resource units can be used for STF, LTF, data fields, and the like.
  • FIG. 5 is a diagram showing the arrangement of a resource unit (RU) used on a 20MHz band.
  • RU resource unit
  • Resource Units corresponding to different numbers of tones (ie, subcarriers) may be used to configure some fields of the HE-PPDU. For example, resources may be allocated in units of RU shown for HE-STF, HE-LTF, and data fields.
  • 26-units i.e., units corresponding to 26 tones
  • Six tones may be used as a guard band in the leftmost band of the 20 MHz band, and five tones may be used as a guard band in the rightmost band of the 20 MHz band.
  • 7 DC tones are inserted into the central band, that is, the DC band, and 26-units corresponding to each of 13 tones may exist on the left and right sides of the DC band.
  • 26-units, 52-units, and 106-units may be allocated to other bands.
  • Each unit can be assigned for a receiving station, ie a user.
  • the RU arrangement of FIG. 5 is utilized not only for a situation for multiple users (MU), but also for a situation for single users (SU).
  • MU multiple users
  • SU single users
  • one 242-unit is used. It is possible to use and in this case 3 DC tones can be inserted.
  • FIG. 6 is a view showing the arrangement of a resource unit (RU) used on the 40MHz band.
  • RU resource unit
  • examples of FIG. 6 may also be 26-RU, 52-RU, 106-RU, 242-RU, 484-RU, and the like.
  • 5 DC tones may be inserted into the center frequency, 12 tones are used in the leftmost band of the 40 MHz band as a guard band, and 11 tones in the rightmost band of the 40 MHz band. It can be used as a guard band.
  • 484-RU when used for a single user, 484-RU can be used. Meanwhile, the fact that the specific number of RUs can be changed is the same as the example of FIG. 4.
  • FIG. 7 is a view showing the arrangement of a resource unit (RU) used on the 80MHz band.
  • RU resource unit
  • examples of FIG. 7 may also be 26-RU, 52-RU, 106-RU, 242-RU, 484-RU, 996-RU, etc. have.
  • 7 DC tones can be inserted into the center frequency, 12 tones are used in the leftmost band of the 80 MHz band as a guard band, and 11 tones are located in the rightmost band of the 80 MHz band. It can be used as a guard band. It is also possible to use 26-RUs with 13 tones located on the left and right sides of the DC band.
  • 996-RU when used for a single user, 996-RU can be used, in which case 5 DC tones can be inserted.
  • the RU arrangement (ie, RU location) shown in FIGS. 5 to 7 may be applied to a new wireless LAN system (eg, EHT system) as it is. Meanwhile, in the 160 MHz band supported by the new WLAN system, the arrangement of the RU for 80 MHz (that is, the example of FIG. 7) is repeated twice or the arrangement of the RU for 40 MHz (that is, the example of FIG. 6) is 4 times It can be repeated. In addition, when the EHT PPDU is configured in the 320 MHz band, the arrangement of RUs for 80 MHz (example of FIG. 7) may be repeated 4 times or the arrangement of RUs for 40 MHz (ie, example of FIG. 6) may be repeated 8 times. have.
  • EHT PPDU is configured in the 320 MHz band
  • the arrangement of RUs for 80 MHz (example of FIG. 7) may be repeated 4 times or the arrangement of RUs for 40 MHz (ie, example of FIG. 6) may be repeated 8 times.
  • One RU in this specification may be allocated for only one STA (eg, non-AP). Or, a plurality of RUs may be allocated for one STA (eg, non-AP).
  • the RU described herein may be used for UL (Uplink) communication and DL (Downlink) communication.
  • the transmitting STA eg, AP
  • the second STA may be assigned a second RU (eg, 26/52/106 / 242-RU, etc.).
  • the first STA may transmit the first Trigger-based PPDU based on the first RU
  • the second STA may transmit the second Trigger-based PPDU based on the second RU.
  • the first / second trigger-based PPDU is transmitted to the AP in the same time interval.
  • the transmitting STA (eg, AP) allocates a first RU (eg, 26/52/106 / 242-RU, etc.) to the first STA, and A second RU (for example, 26/52/106 / 242-RU, etc.) may be allocated to the 2 STAs. That is, the transmitting STA (for example, the AP) can transmit the HE-STF, HE-LTF, and Data fields for the first STA through the first RU in one MU PPDU, and the second STA through the second RU. The HE-STF, HE-LTF, and Data fields for 2 STAs may be transmitted.
  • a first RU eg, 26/52/106 / 242-RU, etc.
  • a second RU for example, 26/52/106 / 242-RU, etc.
  • the HE-STF, HE-LTF, and Data fields for 2 STAs may be transmitted.
  • HE-SIG-B Information on the arrangement of the RU may be signaled through HE-SIG-B.
  • the HE-SIG-B field 810 includes a common field 820 and a user-specific field 830.
  • the common field 820 may include information commonly applied to all users (ie, user STAs) receiving SIG-B.
  • the user-individual field 830 may be referred to as a user-individual control field.
  • the user-individual field 830 may be applied to only some of a plurality of users when SIG-B is delivered to a plurality of users.
  • the common field 920 and the user-individual field 930 may be separately encoded.
  • the common field 920 may include N * 8 bits of RU allocation information.
  • the RU allocation information may include information regarding the location of the RU. For example, when a 20 MHz channel is used as shown in FIG. 5, the RU allocation information may include information on which RU (26-RU / 52-RU / 106-RU) is arranged in which frequency band. .
  • up to nine 26-RUs may be allocated to a 20 MHz channel.
  • the RU allocation information of the common field 820 is set as '00000000' as shown in Table 8
  • nine 26-RUs may be allocated to the corresponding channel (ie, 20 MHz).
  • the RU allocation information of the common field 820 is set as '00000001'
  • seven 26-RUs and one 52-RU are arranged in corresponding channels. That is, in the example of FIG. 5, 52-RU is allocated on the right-most side and seven 26-RU are allocated on the left side.
  • Table 1 shows only a part of RU locations that can be displayed by RU allocation information.
  • the RU allocation information may further include an example of Table 2 below.
  • “01000y2y1y0” is related to an example in which 106-RU is allocated to the left-most side of a 20 MHz channel, and 5 26-RU are allocated to the right.
  • a number of STAs (eg, User-STA) may be assigned to the 106-RU based on the MU-MIMO technique.
  • a maximum of 8 STAs (eg, User-STA) may be allocated to the 106-RU, and the number of STAs (eg, User-STA) allocated to the 106-RU may be 3 bit information (y2y1y0). ).
  • the 3-bit information (y2y1y0) is set to N
  • the number of STAs (eg, User-STA) allocated to the 106-RU based on the MU-MIMO technique may be N + 1.
  • a plurality of different STAs may be assigned to a plurality of RUs.
  • a plurality of STAs may be allocated based on the MU-MIMO technique.
  • the user-individual field 830 may include a plurality of user fields.
  • the number of STAs (eg, User STAs) allocated to a specific channel may be determined based on RU allocation information of the common field 820. For example, when the RU allocation information of the common field 820 is '00000000', one user STA may be allocated to each of the nine 26-RUs (that is, a total of nine user STAs are allocated). That is, up to 9 User STAs may be allocated to a specific channel through OFDMA. In other words, up to 9 User STAs can be assigned to a specific channel through a non-MU-MIMO technique.
  • RU allocation when RU allocation is set to “01000y2y1y0”, a plurality of User STAs are allocated through the MU-MIMO technique to 106-RUs disposed at the left-most side, and five 26-RUs disposed at the right side thereof. Five user STAs may be allocated through a non-MU-MIMO technique. This case is embodied through the example of FIG. 9.
  • RU allocation is set to “01000010” as shown in FIG. 9, based on Table 2, 106-RU is allocated to the left-most of a specific channel and 5 26-RU are allocated to the right. Can be.
  • a total of three User STAs can be allocated to the 106-RU through the MU-MIMO technique.
  • the user-individual field 830 of HE-SIG-B may include 8 User fields.
  • Eight User fields may be included in the order shown in FIG. 9. Also, as illustrated in FIG. 8, two user fields may be implemented as one user block field.
  • the user fields illustrated in FIGS. 8 and 9 may be configured based on two formats. That is, the User field related to the MU-MIMO technique may be configured in the first format, and the User field related to the non-MU-MIMO technique may be configured in the second format. Referring to the example of FIG. 9, User fields 1 to User field 3 may be based on the first format, and User fields 4 to User Field 8 may be based on the second format.
  • the first format or the second format may include bit information of the same length (for example, 21 bits).
  • the transmitting STA may perform channel access through contending (ie, backoff operation) and transmit a trigger frame 1030. That is, the transmitting STA (eg, AP) may transmit the PPDU including the Trigger Frame 1330.
  • a trigger-based (TB) PPDU is transmitted after a delay of SIFS.
  • TB PPDUs 1041 and 1042 may be transmitted at the same time, and may be transmitted from a plurality of STAs (eg, User STAs) whose AIDs are indicated in the Trigger frame 1030.
  • STAs eg, User STAs
  • the ACK frame 1050 for the TB PPDU may be implemented in various forms.
  • an orthogonal frequency division multiple access (OFDMA) technique or MU MIMO technique may be used, and OFDMA and MU MIMO techniques may be used simultaneously.
  • OFDMA orthogonal frequency division multiple access
  • the trigger frame of FIG. 11 allocates resources for uplink multiple-user transmission (MU) transmission and may be transmitted from an AP, for example.
  • the trigger frame may be composed of a MAC frame and may be included in the PPDU.
  • Each field illustrated in FIG. 11 may be partially omitted, and other fields may be added. Also, the length of each field may be changed differently from that shown.
  • the frame control field 1110 of FIG. 11 includes information on the version of the MAC protocol and other additional control information, and the duration field 1120 is time information for NAV setting or an identifier of the STA (eg For example, AID) may be included.
  • the RA field 1130 includes address information of a receiving STA of a corresponding trigger frame, and may be omitted if necessary.
  • the TA field 1140 includes address information of an STA (eg, AP) that transmits the trigger frame, and the common information field 1150 is applied to a receiving STA that receives the trigger frame.
  • Contains control information For example, a field indicating the length of the L-SIG field of the uplink PPDU transmitted corresponding to the trigger frame or a SIG-A field of the uplink PPDU transmitted corresponding to the trigger frame (ie, HE-SIG-A Field) may include information that controls the content.
  • the common control information information on the length of the CP of the uplink PPDU transmitted corresponding to the trigger frame or information on the length of the LTF field may be included.
  • the individual user information field may be referred to as an “assignment field”.
  • the trigger frame of FIG. 11 may include a padding field 1170 and a frame check sequence field 1180.
  • Each of the individual user information fields 1160 # 1 to 1160 # N illustrated in FIG. 11 may include a plurality of subfields again.
  • FIG. 12 shows an example of a common information field of a trigger frame. Some of the subfields of FIG. 12 may be omitted, and other subfields may be added. Also, the length of each of the illustrated sub-fields can be changed.
  • the illustrated length field 1210 has the same value as the length field of the L-SIG field of the uplink PPDU transmitted corresponding to the trigger frame, and the length field of the L-SIG field of the uplink PPDU indicates the length of the uplink PPDU.
  • the length field 1210 of the trigger frame can be used to indicate the length of the corresponding uplink PPDU.
  • cascade indicator field 1220 indicates whether a cascade operation is performed.
  • Cascade operation means that downlink MU transmission and uplink MU transmission are performed together in the same TXOP. That is, after the downlink MU transmission is performed, it means that the uplink MU transmission is performed after a predetermined time (for example, SIFS).
  • a predetermined time for example, SIFS.
  • AP transmission device
  • a plurality of transmission devices eg, non-AP
  • the CS request field 1230 indicates whether a state of a radio medium or NAV should be considered in a situation in which a receiving device receiving a corresponding trigger frame transmits a corresponding uplink PPDU.
  • the HE-SIG-A information field 1240 may include information that controls the content of the SIG-A field (that is, the HE-SIG-A field) of the uplink PPDU transmitted corresponding to the trigger frame.
  • the CP and LTF type field 1250 may include information on the length and CP length of the LTF of the uplink PPDU transmitted corresponding to the corresponding trigger frame.
  • the trigger type field 1060 may indicate the purpose for which the corresponding trigger frame is used, for example, normal triggering, triggering for beamforming, request for Block ACK / NACK, and the like.
  • the trigger type field 1260 of the trigger frame indicates a basic type trigger frame for normal triggering.
  • a basic type trigger frame may be referred to as a basic trigger frame.
  • the user information field 1300 of FIG. 13 shows an example of a sub-field included in a per user information field.
  • the user information field 1300 of FIG. 13 may be understood as any one of the individual user information fields 1160 # 1 to 1160 # N mentioned in FIG. 11. Some of the subfields included in the user information field 1300 of FIG. 13 may be omitted, and other subfields may be added. Also, the length of each of the illustrated sub-fields can be changed.
  • the user identifier (User Identifier) field 1310 of FIG. 13 indicates an identifier of an STA (ie, a receiving STA) corresponding to per user information, and an example of the identifier is an association identifier (AID) of the receiving STA It can be all or part of the value.
  • a RU Allocation field 1320 may be included. That is, when the receiving STA identified by the user identifier field 1310 transmits the TB PPDU in response to the trigger frame, the TB PPDU is transmitted through the RU indicated by the RU allocation field 1320.
  • the RU indicated by the RU Allocation field 1320 may be the RU shown in FIGS. 5, 6, and 7.
  • the sub-field of FIG. 13 may include a coding type field 1330.
  • the coding type field 1330 may indicate a coding type of TB PPDU. For example, when BCC coding is applied to the TB PPDU, the coding type field 1330 may be set to '1', and when LDPC coding is applied, the coding type field 1330 may be set to '0'. have.
  • the sub-field of FIG. 13 may include an MCS field 1340.
  • the MCS field 1340 may indicate an MCS technique applied to TB PPDU. For example, when BCC coding is applied to the TB PPDU, the coding type field 1330 may be set to '1', and when LDPC coding is applied, the coding type field 1330 may be set to '0'. have.
  • the transmitting STA may allocate 6 RU resources as illustrated in FIG. 14 through a trigger frame.
  • the AP includes first RU resources (AID 0, RU 1), second RU resources (AID 0, RU 2), third RU resources (AID 0, RU 3), and fourth RU resources (AID 2045, RU) 4), the fifth RU resource (AID 2045, RU 5), the sixth RU resource (AID 3, RU 6) can be allocated.
  • Information regarding AID 0, AID 3, or AID 2045 may be included, for example, in the user identification field 1310 of FIG. 13.
  • Information about RU 1 to RU 6 may be included in the RU allocation field 1320 of FIG. 13, for example.
  • the first to third RU resources of FIG. 14 may be used as a UORA resource for an associated STA
  • the fourth to fifth RU resources of FIG. 14 for a non-associated STA It may be used as a UORA resource
  • the sixth RU resource of FIG. 14 may be used as a resource for a normal UL MU.
  • the ODMA (OFDMA random access BackOff) counter of STA1 is decreased to 0, so that STA1 randomly selects the second RU resources (AID 0 and RU 2).
  • the OBO counter of STA2 / 3 is larger than 0, uplink resources are not allocated to STA2 / 3.
  • STA1 in FIG. 14 is an associated STA, there are a total of 3 eligible RA RUs for STA1 (RU 1, RU 2, and RU 3), and accordingly, STA1 decreases the OBO counter by 3, resulting in an OBO counter. It became zero.
  • STA2 in FIG. 14 is an associated STA, there are a total of 3 eligible RA RUs for STA2 (RU 1, RU 2, RU 3), and accordingly, STA2 reduces the OBO counter by 3, but the OBO counter is 0. It is in a larger state.
  • STA3 of FIG. 14 is a non-associated STA, there are a total of two eligible RA RUs for STA3 (RU 4 and RU 5), and accordingly, STA3 reduces the OBO counter by 2, but the OBO counter is It is greater than zero.
  • the 2.4 GHz band may be referred to by other names such as the first band (band).
  • the 2.4 GHz band may mean a frequency range in which channels having a center frequency adjacent to 2.4 GHz (eg, channels having a center frequency within 2.4 to 2.5 GHz) are used / supported / defined.
  • the 2.4 GHz band may include multiple 20 MHz channels.
  • 20 MHz in the 2.4 GHz band may have multiple channel indices (eg, indices 1 to 14).
  • the center frequency of a 20 MHz channel to which channel index 1 is allocated may be 2.412 GHz
  • the center frequency of a 20 MHz channel to which channel index 2 is allocated may be 2.417 GHz
  • the 20 MHz to which channel index N is allocated The center frequency of the channel may be (2.407 + 0.005 * N) GHz.
  • the channel index may be called various names such as a channel number. The specific values of the channel index and the center frequency can be changed.
  • the illustrated first frequency domain 1510 to the fourth frequency domain 1540 may each include one channel.
  • the first frequency domain 1510 may include a channel 1 (a 20 MHz channel having an index 1).
  • the center frequency of channel 1 may be set to 2412 MHz.
  • the second frequency domain 1520 may include channel 6.
  • the center frequency of channel 6 may be set to 2437 MHz.
  • the third frequency domain 1530 may include channel 11.
  • the center frequency of the channel 11 may be set to 2462 MHz.
  • the fourth frequency domain 1540 may include channel 14. At this time, the center frequency of the channel 14 may be set to 2484 MHz.
  • 16 shows an example of a channel used / supported / defined within a 5 GHz band.
  • the 5 GHz band may be referred to by other names such as the second band / band.
  • the 5 GHz band may refer to a frequency range in which channels having a center frequency of 5 GHz or more and less than 6 GHz (or less than 5.9 GHz) are used / supported / defined.
  • the 5 GHz band may include a plurality of channels between 4.5 GHz and 5.5 GHz. The specific numerical values shown in FIG. 16 may be changed.
  • a plurality of channels in the 5 GHz band includes UNII (Unlicensed National Information Infrastructure) -1, UNII-2, UNII-3, and ISM.
  • UNII-1 can be called UNII Low.
  • UNII-2 may include frequency domains called UNII Mid and UNII-2Extended.
  • UNII-3 can be called UNII-Upper.
  • Multiple channels may be set in the 5 GHz band, and the bandwidth of each channel may be variously set to 20 MHz, 40 MHz, 80 MHz, or 160 MHz.
  • the 5170 MHz to 5330 MHz frequency range / range in UNII-1 and UNII-2 may be divided into eight 20 MHz channels.
  • the 5170 MHz to 5330 MHz frequency domain / range can be divided into four channels through the 40 MHz frequency domain.
  • the 5170 MHz to 5330 MHz frequency domain / range may be divided into two channels through the 80 MHz frequency domain.
  • the 5170 MHz to 5330 MHz frequency domain / range may be divided into one channel through the 160 MHz frequency domain.
  • FIG. 17 shows an example of a channel used / supported / defined within a 6 GHz band.
  • the 6 GHz band may be referred to by other names such as third band / band.
  • the 6 GHz band may mean a frequency domain in which channels with a center frequency of 5.9 GHz or higher are used / supported / defined.
  • the specific numerical values shown in FIG. 17 may be changed.
  • the 20 MHz channel of FIG. 17 may be defined from 5.940 GHz.
  • the left-most channel may have an index 1 (or a channel index, a channel number, etc.), and a center frequency of 5.945 GHz may be allocated. That is, the center frequency of the index N channel may be determined as (5.940 + 0.005 * N) GHz.
  • the index (or channel number) of the 20 MHz channel in FIG. 17 is 1, 5, 9, 13, 17, 21, 25, 29, 33, 37, 41, 45, 49, 53, 57, 61, 65, 69, 73, 77, 81, 85, 89, 93, 97, 101, 105, 109, 113, 117, 121, 125, 129, 133, 137, 141, 145, 149, 153, 157, 161, 165, 169, 173, 177, 181, 185, 189, 193, 197, 201, 205, 209, 213, 217, 221, 225, 229, 233.
  • the index of the 40 MHz channel of FIG. 17 is 3, 11, 19, 27, 35, 43, 51, 59, 67, 75, 83, 91, 99, 107, 115, 123, 131, 139, 147, 155, 163, 171, 179, 187, 195, 203, 211, 219, 227.
  • the PPDU of FIG. 18 may be called various names such as an EHT PPDU, a transmitting PPDU, a receiving PPDU, a first type or an N-type PPDU.
  • EHT PPDU transmitting PPDU
  • receiving PPDU receives a packet data packet
  • N-type PPDU receives a packet data packet
  • it can be used in a new wireless LAN system with an improved EHT system and / or EHT system.
  • the sub-field of FIG. 18 may be changed to various names.
  • the SIG A field may be called an EHT-SIG-A field
  • the SIG B field an EHT-SIG-B
  • the STF field an EHT-STF field
  • the LTF field an EHT-LTF field.
  • the subcarrier spacing of the L-LTF, L-STF, L-SIG, and RL-SIG fields of FIG. 18 may be determined as 312.5 kHz, and the subcarrier spacing of the STF, LTF, and Data fields may be determined as 78.125 kHz. That is, the subcarrier index of the L-LTF, L-STF, L-SIG, and RL-SIG fields may be displayed in 312.5 kHz units, and the subcarrier index of the STF, LTF, and Data fields may be displayed in 78.125 kHz units.
  • the SIG A and / or SIG B fields of FIG. 18 may include additional fields (eg, SIG C or one control symbol, etc.).
  • the subcarrier spacing of all / part of the SIG A and SIG B fields may be set to 312.5 kHz, and the subcarrier spacing of the remaining portions may be set to 78.125 kHz.
  • the PPDU of FIG. 18 may have the same L-LTF and L-STF fields.
  • the L-SIG field of FIG. 18 may include, for example, 24-bit bit information.
  • the 24-bit information may include a rate field of 4 bits, a reserved bit of 1 bit, a length field of 12 bits, a parity bit of 1 bit, and a tail bit of 6 bits.
  • the 12-bit Length field may include information on the number of octets of the PSDU (Physical Service Data Unit).
  • the value of the 12-bit Length field may be determined based on the type of PPDU. For example, if the PPDU is a non-HT, HT, VHT PPDU or an EHT PPDU, the value of the Length field may be determined in multiples of 3.
  • the value of the Length field may be determined as “multiple of 3 + 1” or “multiple of 3 +2”.
  • the value of the Length field can be determined as a multiple of 3 for non-HT, HT, VHT PPDU or EHT PPDU, and the value of the Length field for HE PPDU is a multiple of 3 + 1 or multiple of 3 +2 ”.
  • the transmitting STA may apply BCC encoding based on a code rate of 1/2 to the 24-bit information of the L-SIG field. Thereafter, the transmitting STA may acquire 48 bits of BCC coded bits. For the 48-bit coded bit, BPSK modulation may be applied to generate 48 BPSK symbols. The transmitting STA may map 48 BPSK symbols to positions excluding pilot subcarriers ⁇ subcarrier index -21, -7, +7, +21 ⁇ and DC subcarrier ⁇ subcarrier index 0 ⁇ .
  • the transmitting STA may further map the signals of ⁇ -1, -1, -1, 1 ⁇ to the subcarrier index ⁇ -28, -27, +27, 28 ⁇ .
  • the above signal can be used for channel estimation for the frequency domain corresponding to ⁇ -28, -27, +27, 28 ⁇ .
  • the transmitting STA may generate the RL-SIG generated in the same way as the L-SIG. BPSK modulation is applied to RL-SIG.
  • the receiving STA can know that the received PPDU is an HE PPDU or an EHT PPDU based on the presence of the RL-SIG.
  • EHT-SIG-A or one control symbol may be inserted.
  • the symbol (i.e., EHT-SIG-A or one control symbol) contiguous to the RL-SIG may include 26 bits of information and may include information for identifying the type of the EHT PPDU.
  • EHT PPDU type information may be included in a symbol subsequent to the RL-SIG.
  • Symbols subsequent to the RL-SIG may include, for example, information about the length of the TXOP and information about the BSS color ID.
  • a SIG-A field may be configured in succession to a symbol (eg, one control symbol) consecutive to RL-SIG.
  • a symbol subsequent to RL-SIG may be a SIG-A field.
  • the SIG-A field is 1) a DL / UL indicator, 2) a BSS color field that is an identifier of a BSS, 3) a field including information on the remaining time of the current TXOP section, 4) a bandwidth.
  • Bandwidth field including information 5) Field including information on MCS technique applied to SIG-B, 6) Contains information related to whether dual subcarrier modulation technique is applied to SIG-B Indication field, 7) a field including information on the number of symbols used for SIG-B, 8) a field including information on whether SIG-B is generated over the entire band, 9) LTF / STF A field including information on the type of 10, 10) may include information on a field indicating the length of the LTF and CP length.
  • the STF of FIG. 18 may be used to improve automatic gain control estimation in a multiple input multiple output (MIMO) environment or OFDMA environment.
  • the LTF of FIG. 18 can be used to estimate a channel in a MIMO environment or an OFDMA environment.
  • the STF of FIG. 18 can be set to various types.
  • a first type that is, 1x STF
  • the STF signal generated based on the first type STF sequence may have a period of 0.8 ⁇ s, and the period signal of 0.8 ⁇ s may be repeated 5 times to become a first type STF having a length of 4 ⁇ s.
  • a second type that is, 2x STF
  • a second type that is, 2x STF
  • STF among STFs may be generated based on a second type STF sequence in which non-zero coefficients are arranged at 8 subcarrier intervals.
  • the STF signal generated based on the second type STF sequence may have a period of 1.6 ⁇ s, and the period signal of 1.6 ⁇ s may be repeated 5 times to become a second type EHT-STF having a length of 8 ⁇ s.
  • a third type of STF ie, 4x EHT-STF
  • the STF signal generated based on the third type STF sequence may have a period of 3.2 ⁇ s, and the period signal of 3.2 ⁇ s may be repeated 5 times to become a third type EHT-STF having a length of 16 ⁇ s.
  • the EHT-LTF field may have first, second, and third types (ie, 1x, 2x, 4x LTF).
  • the first / second / third type LTF field may be generated based on an LTF sequence in which non-zero coefficients are arranged at 4/2/1 subcarrier intervals.
  • the first / second / third type LTF may have a time length of 3.2 / 6.4 / 12.8 ⁇ s.
  • various lengths of GI eg, 0.8 / 1/6 / 3.2 ⁇ s
  • Information about the type of STF and / or LTF may be included in the SIG A field and / or the SIG B field of FIG. 18.
  • the PPDU of FIG. 18 may be identified as an EHT PPDU based on the following method.
  • the receiving STA may determine the type of the received PPDU as the EHT PPDU based on the following. For example, 1) the first symbol after the L-LTF signal of the received PPDU is BPSK, 2) the RL-SIG where the L-SIG of the received PPDU is repeated is detected, and 3) the length of the L-SIG of the received PPDU. When the result of applying “modulo 3” to the value is detected as “0”, the received PPDU may be determined as the EHT PPDU. If the received PPDU is determined to be the EHT PPDU, the receiving STA is based on the bit information included in the symbol after RL-SIG in FIG.
  • the receiving STA is 1) the first symbol after the L-LTF signal, which is the BSPK, 2) the result of applying the RL-SIG identical to the L-SIG in the L-SIG field and 3) “modulo 3”. Based on the L-SIG including the Length field set to “0”, the received PPDU can be determined as the EHT PPDU.
  • the receiving STA may determine the type of the received PPDU as HE PPDU based on the following. For example, 1) the first symbol after the L-LTF signal is BPSK, 2) the RL-SIG where the L-SIG is repeated is detected, and 3) “modulo 3” is applied to the length value of the L-SIG. When the result is detected as "1" or "2", the received PPDU may be determined as the HE PPDU.
  • the receiving STA may determine the type of the received PPDU as non-HT, HT and VHT PPDU based on the following. For example, 1) the first symbol after the L-LTF signal is BPSK, 2) the RL-SIG where the L-SIG is repeated is not detected, and 3) “modulo 3” for the length value of the L-SIG. When the applied result is detected as “0”, the received PPDU can be determined as non-HT, HT and VHT PPDU.
  • CSMA / CA carrier sense multiple access / collision avoidance
  • IEEE 802.11 communication is performed in a shared wireless medium, so it has fundamentally different characteristics from a wired channel environment.
  • a wired channel environment communication was possible based on carrier sense multiple access / collision detection (CSMA / CD).
  • CSMA / CD carrier sense multiple access / collision detection
  • the channel environment does not change significantly, so Rx is transmitted without experiencing a large signal attenuation.
  • detection was possible. This is because the power detected at the Rx stage is instantaneously greater than the power transmitted by Tx.
  • various factors for example, signal attenuation may be large depending on distance or may experience instantaneous deep fading) affect the channel.
  • Tx cannot accurately perform carrier sensing.
  • DCF distributed coordination function
  • CSMA / CA carrier sense multiple access / collision avoidance
  • the random backoff period enables collision avoidance, because assuming that there are several STAs for transmitting data, each STA has a different probability of backoff interval and eventually has a different transmission time. to be. When one STA starts transmitting, other STAs cannot use the medium.
  • the random backoff time and procedure are as follows. When a certain medium changes from busy to idle, several STAs start preparing to send data. At this time, in order to minimize collision, STAs that want to transmit data each select a random backoff count and wait for the slot time.
  • the random backoff count is a pseudo-random integer value, and one of the uniform distribution values in the [0 CW] range is selected.
  • CW stands for contention window.
  • the CW parameter takes the CWmin value as the initial value, but if the transmission fails, the value is doubled. For example, if an ACK response for a transmitted data frame is not received, collision may be considered.
  • the STA selects a random backoff count within the [0 CW] range and continuously monitors the medium while the backoff slot is counted down. In the meantime, when the medium becomes busy, the count down is stopped. When the medium becomes idle again, the countdown of the remaining backoff slot is resumed.
  • the terminal uses physical carrier sense and virtual carrier sense to determine whether the DCF medium is busy / idle.
  • Physical carrier sense is achieved at the PHY (physical layer) stage and is performed through energy detection or preamble detection. For example, if it is determined that the voltage level at the Rx stage is read or the preamble is read, it can be determined that the medium is busy.
  • Virtual carrier sense is to prevent other STAs from transmitting data by setting a network allocation vector (NAV), which is achieved through the value of the Duration field of the MAC header.
  • NAV network allocation vector
  • the PHY transmit procedure is converted to a single PSDU (PHY service data unit) in the PHY stage when an MACDU (MAC protocol data unit) or A-MPDU (Aggregate MPDU) comes from the MAC stage, and preamble and tail bits, padding bits (if necessary) ), And this is called a PPDU.
  • PSDU PHY service data unit
  • A-MPDU Aggregate MPDU
  • the PHY receive procedure is usually as follows. When energy detection and preamble detection (L / HT / VHT / HE-preamble detection for each Wifi version) are performed, information on PSDU configuration is obtained from the PHY header (L / HT / VHT / HE-SIG), MAC header is read, and data Read
  • Mesh Wi-Fi (Multi-AP solution) is well accepted in the market for better coverage, easy deployment and high throughput.
  • AP 1 sends an adjustment signal to AP 2 and AP 3 to start joint transmission.
  • AP 2 and AP 3 transmit and receive data with multiple STAs using OFDMA and MU-MIMO in one data packet.
  • STA 2 and STA 3 are in different resource units (RUs), and each RU is a frequency segment.
  • STA 1 and STA 4 are in the same resource unit using MU-MIMO.
  • Each RU may be transmitted in a multi-space stream.
  • 20 is a diagram illustrating multiple AP adjustment.
  • Multiple AP coordination utilizes wired (eg, enterprise) or wireless (eg, home mesh) backbone for data + clock synchronization.
  • multi-AP coordination has improved link budget and regulated power limits than a single AP with a large antenna array.
  • the techniques of multi-AP steering include null steering for interference avoidance, joint beamforming, and joint MU-MIMO.
  • Null steering for interference avoidance is useful when the AP has a large dimension (4x4 or 8x8).
  • 22 shows an example in which AP coordination and interference are controlled.
  • Coordinated scheduling mitigates / decreases the number of collisions from AP / STA of another BSS.
  • coordinated scheduling is a distributed mechanism and increases the number / probability of parallel transmissions in a coordinated manner rather than spatial reuse. It is necessary to exchange messages between APs.
  • Coordinated beamforming allows simultaneous downlink transmission without co-channel interference caused by beamforming, such as designating a nulling point to another STA or distributed joint beamforming. have.
  • coordinated beamforming is suitable for managed deployments (eg, corporate offices, hotels), and has the advantage of area throughput and a consistent user experience.
  • the adjusted beamforming requires adjusted downlink scheduling and improved MU sounding to reduce overhead, synchronization, and the like.
  • the solid arrow in FIG. 24 indicates data transmission in the BSS STA, and the dotted arrow in FIG. 24 is null transmitted to OBSS STAs.
  • a signal for the user is transmitted from only one AP while forming null in the OBSS STA.
  • 25 is a view for explaining C-OFDMA.
  • C-OFDMA Coordinated-OFDMA
  • C-OFDMA is an extension of 11ax OFDMA from a single BSS to multiple BSS scenarios.
  • C-OFDMA efficiently utilizes frequency resources throughout the network.
  • C-OFDMA improves efficiency when BSS traffic does not fully utilize resources.
  • a spectrum 2510 used for transmission of BSS1 and a spectrum 2520 used for transmission of BSS2 exist in a total of 40 MHz band in a 20 MHz band. Synchronized transmission can be performed to obtain orthogonality.
  • the spectrum 2510 used for the transmission of BSS1 is assigned STAs 1 to 3
  • the spectrum 2520 used for the transmission of BSS2 is assigned STAs 4 and 5.
  • 26 shows an example of the joint transmission.
  • one STA is serviced by AP1 and AP2.
  • Joint transmissions may have more stringent synchronization requirements and should be considered separately. Joint transmission may be performed more easily than joint processing transmission for multiple STAs. However, joint transmission may exploit beamforming and power gain from multiple APs.
  • 27 shows an example of performing joint transmission through M-AP and S-AP.
  • the M-AP serves as an AP coordinator.
  • S-AP (Slave AP) participates in joint transmission coordinated by M-AP and may have both STA and AP functions. Referring to FIG. 27, S-AP1 and S-AP2 have a STA function in a coordination step and an AP function in a joint transmission step.
  • multi-AP coordination technology minimizes interference between BSSs during data transmission / reception or transmits / receives data to / from the terminal by sharing channel feedback information and scheduling information of the terminal between APs when transmitting and receiving data frames between the terminal and the AP. This is a method of increasing data transmission efficiency by participating in two or more APs at a time.
  • such multi-AP coordination technology has not been standardized yet.
  • IEEE802.11 EHT TIG discussion on standardization related to multi-AP coordination with the next wi-fi technology is ongoing. In this specification, we propose a method in which multiple APs can perform joint transmission by using Multi-AP coordination in a Wi-Fi system.
  • a master AP selects a plurality of APs performing multi-AP communication by performing a selection procedure for coordinating multiple APs with slave-APs (S-APs).
  • S-AP 1 to S-AP 3 selected by the M-AP may perform a sounding procedure to perform joint transmission to the STA.
  • the description of the M-AP, S-AP (s) and STA shown in FIG. 28 is as follows.
  • JTX Joint Transmission
  • the Master AP manages links with Slave-APs to group Slave-APs and share information between Slave-APs.
  • the Master AP manages the information of the BSS configured by the Slave APs and the STAs associated with the BSS.
  • -Slave-AP can establish control association with Master AP to share control information, management information, and data traffic with each other.
  • -Slave-AP basically performs the same function as the AP that can form the BSS in the existing WLAN.
  • -STA configures BSS by associating with Slave AP or Master AP as in the existing WLAN.
  • -Slave AP associated with STA
  • STA can directly transmit and receive each other.
  • One of the Slave APs can be the Master AP.
  • 29 shows an example of joint transmission when direct transmission / reception between M-AP and STA is possible.
  • the M-AP selects S-AP through a sounding procedure and performs joint transmission to the STA together with the selected S-AP. Details will be described later.
  • the M-AP selects S-AP through a sounding procedure, and only selected S-APs can perform joint transmission for the STA. Details will be described later.
  • the joint transmission procedure of FIGS. 29 and 30 may be composed of steps 1) to 7).
  • the Master AP sends a JTX trigger frame to Slave AP 1, Slave AP 2, and Slave AP 3 (2910, 3010).
  • -JTX trigger frame is transmitted to multiple Slave APs at once.
  • the Master AP may transmit a JTX trigger frame only to specific Slave APs or all Slave APs that can receive a JTX trigger frame transmitted by a Mater AP.
  • -Slave APs that receive JTX trigger frames operate to match the Master AP or Slave APs with synchronization (Timing, carrier frequency offset (CFO), sampling frequency offset (SFO), and phase drift).
  • the Slave AP (Slave AP 1) associated with the STA prepares to transmit a NDP (Null Data Packet) request frame.
  • NDP Null Data Packet
  • Slave AP (associated with STA) transmits a JTX NDP request frame to the STA (3020).
  • the JTX NDP request frame can be transmitted in a control mode using the SU PPDU format.
  • the STA receiving the JTX NDP request prepares to transmit the JTX NDP.
  • step 2) If the STA can directly receive the frame transmitted by the Master AP, the procedure of step 2) may be omitted, and the Master AP may directly transmit the JTX NDP request frame to the STA (2920).
  • the content included in the JTX trigger frame and JTX NDP request of FIG. 29 and the JTX trigger frame and JTX NDP request of FIG. 30 may be the same.
  • the Master AP may perform steps 1) and 2) at the same time.
  • STA transmits the JTX NDP frame to Slave APs (2930, 3030).
  • the STA transmits only the preamble as in the existing NDP format or includes information indicating the slave APs to be received using the newly defined JTX NDP frame.
  • the content is included in the PHY header, and when the STA sends the newly defined JTX NDP frame to indicate the Slave APs, the content is included in the payload.
  • -Slave APs that have received the JTX NDP frame each have channel information with the corresponding STA (received signal strength indicator (RSSI), signal-to-noise ratio (SNR), signal-to-interference-plus-noise ratio (SINR), etc. ).
  • RSSI received signal strength indicator
  • SNR signal-to-noise ratio
  • SINR signal-to-interference-plus-noise ratio
  • SINR signal-to-interference-plus-noise ratio
  • the Slave APs can clearly see if the JTX NDP frame is from them.
  • Channel reciprocity means a method of estimating a downlink (DL) channel through a sounding procedure of an uplink (UL) channel.
  • the STA may transmit a new JTX NDP frame including only LTF for one stream without using an existing NDP frame. At this time, the STA can only report the power strength and does not support Multi-Input Multi-Output (MIMO) when transmitting a JTX NDP frame. At this time, it is possible to check whether the frames that the Slave APs came to fit by including the indicators of Slave APs in the newly defined frame.
  • MIMO Multi-Input Multi-Output
  • the Master AP transmits a JTX NDP feedback trigger frame to Slave APs (2940, 3040).
  • the JTX NDP feedback trigger frame is a frame for requesting or triggering a JTX NDP feedback frame.
  • the Master AP transmits the JTX NDP feedback trigger frame to the corresponding Slave APs at once.
  • JTX -Slave AP indicators included in the JTX trigger frame and indicators of the Slave APs are included in the JTX NDP feedback trigger frame.
  • JTX NDP feedback trigger frame operate to synchronize the Master AP or Slave APs (Timing, CFO, SFO, Phase drift), and prepare to transmit the JTX NDP feedback frame.
  • -Slave APs transmit JTX NDP feedback frames in UL MU-MIMO or UL MU-OFDMA.
  • JTX NDP feedback frames may be transmitted in order of one Slave AP at the same time.
  • the JTX NDP feedback frame includes channel estimation values between each Slave AP and the corresponding STA.
  • the Master AP receiving the JTX NDP feedback frame combines the individual channel estimation values between the Slave APs and the corresponding STA into one channel, and selects the Slave APs most suitable for the JTX based on the combined channel information.
  • the Master AP transmits a JTX selection frame to selected Slave APs based on JTX NDP feedback (2960, 3060).
  • the JTX selection frame is transmitted only to the Slave APs that will finally participate in JTX.
  • data can be transmitted between the Master AP and the Slave APs by including data to be transmitted to JTX.
  • the JTX selection frame includes antenna information to be used for each Slave AP, number of streams, and information on JTX settings such as Modulation and Coding Scheme (MCS).
  • MCS Modulation and Coding Scheme
  • the JTX selection frame contains the addresses or indicators of slave APs that will participate in JTX.
  • the JTX selection frame may include data to be transmitted to JTX.
  • the Master AP may share the same data with each Slave AP or different data.
  • the Master AP can send the JTX NDP request once again before performing data sharing to the Slave APs to perform the channel estimation procedure for the JTX and finally select the Slave APs to participate in the JTX.
  • channel estimation for JTX can be performed using a JTX NDP frame transmitted by the selected Slave APs to the STA through the selection procedure. That is, since channel reciprocity is not supported, the selected Slave APs can perform channel estimation by directly transmitting a JTX NDP frame to DL.
  • the selected Slave APs transmit data to the corresponding STA using JTX (2970, 3070).
  • the Master AP can transmit data using JTX with the selected Slave AP 1 (2970).
  • 31 is a flowchart illustrating a procedure for performing joint transmission in a transmitting STA according to the present embodiment.
  • the example of FIG. 31 may be performed in a network environment in which a next generation wireless LAN system is supported.
  • the next-generation wireless LAN system is a wireless LAN system (EHT or 802.11be) that improves the 802.11ax system and may satisfy backward compatibility with the 802.11ax system.
  • EHT or 802.11be wireless LAN system
  • This embodiment is performed by a transmitting STA, and the transmitting STA may correspond to an M-AP.
  • the receiving STA of this embodiment is an STA supporting an EHT (Extremely High Throughput) WLAN system, and is received by the first S-AP, second S-AP, or third S-AP through a joint transmission to a STA that receives data. You can respond.
  • EHT Extremely High Throughput
  • a master-access point selects first to third slave-access points (S-APs) to participate in the joint transmission.
  • step S3120 the M-AP manages a link with the first to third S-APs to share the first information between the first to third S-APs.
  • step S3130 the M-AP performs the joint transmission to a STA (station) through the first to third S-APs based on the first information.
  • the M-AP is based on a connection with the first to third S-APs, information about a basic service set (BSS) of the first to third S-APs, and information about a STA associated with the BSS. Can be obtained.
  • BSS basic service set
  • the first information may include control information, management information, and data traffic information for the joint transmission.
  • the M-AP may transmit a joint transmission trigger frame to the first to third S-APs.
  • the joint transmission trigger frame may include information about the address of the STA, the BSS to which the STA belongs, and the address of the S-AP associated with the STA. Synchronization between the M-AP and the first to third S-APs may be performed based on the joint transmission trigger frame.
  • a joint transmission NDP (Null Data Packet) request frame may be transmitted to the STA by the first S-AP.
  • the joint transmission NDP request frame may include information about the address of the STA and the address of the S-AP to receive the joint transmission NDP frame.
  • the joint transmission NDP frame may be transmitted to the first to third S-APs by the STA.
  • the joint transmission NDP frame may include information on the address of the S-AP to receive the joint transmission NDP frame.
  • channel estimation between the first to third S-APs and the STA is performed, channel information between the first to third S-APs and the STA is obtained, and the first The synchronization between the third S-AP and the STA may be performed.
  • the channel information may include a received signal strength indicator (RSSI), a signal-to-noise ratio (SNR), and a signal-to-interference-plus-noise ratio (SINR).
  • RSSI received signal strength indicator
  • SNR signal-to-noise ratio
  • SINR signal-to-interference-plus-noise ratio
  • Channel reciprocity is a method of estimating a downlink (DL) channel through a sounding procedure of an uplink (UL) channel.
  • the UL MU transmission of the STA (joint transmission NDP) is performed using channel reciprocity.
  • Frame a method for performing estimation of DL channels of S-APs will be described.
  • the M-AP may transmit a joint transmission NDP feedback trigger frame to the first to third S-APs.
  • the M-AP may receive a joint transmission NDP feedback frame in response to the joint transmission NDP feedback trigger frame from the first to third S-APs.
  • the M-AP may select the optimal S-AP for the joint transmission based on the joint transmission NDP feedback frame.
  • the joint transmission NDP feedback frame may include channel information in which individual values of channel estimation performed between the first to third S-APs and the STA are combined into one.
  • the optimal S-AP for the joint transmission may be selected as the first and second S-APs based on the channel information combined into the one.
  • the M-AP may transmit a joint transmission selection frame to the first and second S-APs.
  • the joint transmission selection frame is based on data to be used for the joint transmission, antennas to be used by the first and second S-APs, the number of streams supported by the first and second S-APs, and modulation and coding scheme (MCS). Information.
  • MCS modulation and coding scheme
  • the data can be shared between the M-AP and the first and second S-APs.
  • the data may be transmitted to the STA by the first and second S-APs. That is, joint transmission by multiple APs may be performed through the above-described procedure.
  • the joint transmission NDP frame includes only a Long Training Field (LTF) for one stream. Can be.
  • LTF Long Training Field
  • MIMO multi-input multi-output
  • the joint transmission NDP frame may be transmitted to the STA by the first and second S-APs.
  • 32 is a flowchart illustrating a procedure for receiving data through joint transmission in a receiving STA according to the present embodiment.
  • the example of FIG. 32 may be performed in a network environment in which a next generation wireless LAN system is supported.
  • the next-generation wireless LAN system is a wireless LAN system (EHT or 802.11be) that improves the 802.11ax system and may satisfy backward compatibility with the 802.11ax system.
  • EHT or 802.11be wireless LAN system
  • This embodiment is performed at the receiving STA, and the receiving STA is an STA supporting an Extreme High Throughput (EHT) wireless LAN system, and performs joint transmission from the first S-AP, the second S-AP, or the third S-AP. It may correspond to the STA receiving the data.
  • the transmitting STA of this embodiment may correspond to the M-AP.
  • a STA station receives the data from the first and second S-AP (Slave-Access Point) through the joint transmission.
  • step S3220 the STA decodes the data.
  • the first and second S-APs are S-APs selected by a master-access point (M-AP) among the first to third S-APs.
  • M-AP master-access point
  • the M-AP and the first to third S-AP links are established.
  • the data is received based on the first information.
  • the M-AP is based on a connection with the first to third S-APs, information about a basic service set (BSS) of the first to third S-APs, and information about a STA associated with the BSS. Can be obtained.
  • BSS basic service set
  • the first information may include control information, management information, and data traffic information for the joint transmission.
  • the M-AP may transmit a joint transmission trigger frame to the first to third S-APs.
  • the joint transmission trigger frame may include information about the address of the STA, the BSS to which the STA belongs, and the address of the S-AP associated with the STA. Synchronization between the M-AP and the first to third S-APs may be performed based on the joint transmission trigger frame.
  • a joint transmission NDP (Null Data Packet) request frame may be transmitted to the STA by the first S-AP.
  • the joint transmission NDP request frame may include information about the address of the STA and the address of the S-AP to receive the joint transmission NDP frame.
  • the joint transmission NDP frame may be transmitted to the first to third S-APs by the STA.
  • the joint transmission NDP frame may include information on the address of the S-AP to receive the joint transmission NDP frame.
  • channel estimation between the first to third S-APs and the STA is performed, channel information between the first to third S-APs and the STA is obtained, and the first The synchronization between the third S-AP and the STA may be performed.
  • the channel information may include a received signal strength indicator (RSSI), a signal-to-noise ratio (SNR), and a signal-to-interference-plus-noise ratio (SINR).
  • RSSI received signal strength indicator
  • SNR signal-to-noise ratio
  • SINR signal-to-interference-plus-noise ratio
  • Channel reciprocity is a method of estimating a downlink (DL) channel through a sounding procedure of an uplink (UL) channel.
  • the STA uses UL MU transmission (joint transmission NDP) using channel reciprocity. Frame), a method for performing estimation of DL channels of S-APs will be described.
  • the M-AP may transmit a joint transmission NDP feedback trigger frame to the first to third S-APs.
  • the M-AP may receive a joint transmission NDP feedback frame in response to the joint transmission NDP feedback trigger frame from the first to third S-APs.
  • the M-AP may select the optimal S-AP for the joint transmission based on the joint transmission NDP feedback frame.
  • the joint transmission NDP feedback frame may include channel information in which individual values of channel estimation performed between the first to third S-APs and the STA are combined into one.
  • the optimal S-AP for the joint transmission may be selected as the first and second S-APs based on the channel information combined into the one.
  • the M-AP may transmit a joint transmission selection frame to the first and second S-APs.
  • the joint transmission selection frame is based on data to be used for the joint transmission, antennas to be used by the first and second S-APs, the number of streams supported by the first and second S-APs, and modulation and coding scheme (MCS). Information.
  • MCS modulation and coding scheme
  • the data can be shared between the M-AP and the first and second S-APs.
  • the data may be transmitted to the STA by the first and second S-APs. That is, joint transmission by multiple APs may be performed through the above-described procedure.
  • the joint transmission NDP frame includes only a Long Training Field (LTF) for one stream. Can be.
  • LTF Long Training Field
  • MIMO multi-input multi-output
  • the joint transmission NDP frame may be transmitted to the STA by the first and second S-APs.
  • FIG 33 shows a more detailed wireless device implementing an embodiment of the present invention.
  • the present invention described above for the transmitting device or the receiving device can be applied to this embodiment.
  • the wireless device includes a processor 610, a power management module 611, a battery 612, a display 613, a keypad 614, a subscriber identification module (SIM) card 615, a memory 620, and a transceiver 630 ), One or more antennas 631, a speaker 640 and a microphone 641.
  • a processor 610 a power management module 611, a battery 612, a display 613, a keypad 614, a subscriber identification module (SIM) card 615, a memory 620, and a transceiver 630 ), One or more antennas 631, a speaker 640 and a microphone 641.
  • SIM subscriber identification module
  • the processor 610 may be configured to implement the proposed functions, procedures and / or methods described herein. Layers of the radio interface protocol may be implemented in the processor 610.
  • the processor 610 may include an application-specific integrated circuit (ASIC), other chipsets, logic circuits, and / or data processing devices.
  • the processor may be an application processor (AP).
  • the processor 610 may include at least one of a digital signal processor (DSP), a central processing unit (CPU), a graphics processing unit (GPU), and a modem (modulator and demodulator).
  • DSP digital signal processor
  • CPU central processing unit
  • GPU graphics processing unit
  • modem modulator and demodulator
  • processors 610 include SNAPDRAGONTM series processors manufactured by Qualcomm®, EXYNOSTM series processors manufactured by Samsung®, A series processors manufactured by Apple®, HELIOTM series processors manufactured by MediaTek®, and INTEL®. It may be an ATOMTM series processor manufactured by or a corresponding next-generation processor.
  • the power management module 611 manages power for the processor 610 and / or the transceiver 630.
  • the battery 612 supplies power to the power management module 611.
  • the display 613 outputs the results processed by the processor 610.
  • Keypad 614 receives input to be used by processor 610.
  • the keypad 614 may be displayed on the display 613.
  • the SIM card 615 is an integrated circuit used to securely store an international mobile subscriber identity (IMSI) used to identify and authenticate a subscriber in a mobile phone device such as a mobile phone and a computer, and a key associated therewith. Many SIM cards can also store contact information.
  • IMSI international mobile subscriber identity
  • the memory 620 is operatively coupled with the processor 610, and stores various information for operating the processor 610.
  • the memory 620 may include read-only memory (ROM), random access memory (RAM), flash memory, a memory card, a storage medium, and / or other storage devices.
  • ROM read-only memory
  • RAM random access memory
  • flash memory a memory card
  • storage medium e.g., hard disk drives
  • / or other storage devices e.g, hard disk drives, a hard disk drives, a hard disk drives, and the like.
  • modules may be stored in memory 620 and executed by processor 610.
  • the memory 620 may be implemented inside the processor 610. Alternatively, the memory 620 may be implemented outside the processor 610 and may be communicatively connected to the processor 610 through various means known in the art.
  • the transceiver 630 is operatively coupled with the processor 610, and transmits and / or receives wireless signals.
  • the transceiver 630 includes a transmitter and a receiver.
  • the transmitting and receiving unit 630 may include a baseband circuit for processing radio frequency signals.
  • the transmitting and receiving unit controls one or more antennas 631 to transmit and / or receive wireless signals.
  • the speaker 640 outputs sound-related results processed by the processor 610.
  • the microphone 641 receives sound-related inputs to be used by the processor 610.
  • the processor 610 selects first to third slave-access points (S-APs) to participate in the joint transmission, and shares first information between the first to third S-APs
  • S-APs slave-access points
  • the joint transmission to the STA (station) is performed through the first to third S-APs based on the first information.
  • the processor 610 receives the data through the joint transmission from the first and second slave-access points (S-APs) and decodes the data.
  • S-APs slave-access points
  • the M-AP is based on a connection with the first to third S-APs, information about a basic service set (BSS) of the first to third S-APs, and information about a STA associated with the BSS. Can be obtained.
  • BSS basic service set
  • the first information may include control information, management information, and data traffic information for the joint transmission.
  • the M-AP may transmit a joint transmission trigger frame to the first to third S-APs.
  • the joint transmission trigger frame may include information about the address of the STA, the BSS to which the STA belongs, and the address of the S-AP associated with the STA. Synchronization between the M-AP and the first to third S-APs may be performed based on the joint transmission trigger frame.
  • a joint transmission NDP (Null Data Packet) request frame may be transmitted to the STA by the first S-AP.
  • the joint transmission NDP request frame may include information about the address of the STA and the address of the S-AP to receive the joint transmission NDP frame.
  • the joint transmission NDP frame may be transmitted to the first to third S-APs by the STA.
  • the joint transmission NDP frame may include information on the address of the S-AP to receive the joint transmission NDP frame.
  • channel estimation between the first to third S-APs and the STA is performed, channel information between the first to third S-APs and the STA is obtained, and the first The synchronization between the third S-AP and the STA may be performed.
  • the channel information may include a received signal strength indicator (RSSI), a signal-to-noise ratio (SNR), and a signal-to-interference-plus-noise ratio (SINR).
  • RSSI received signal strength indicator
  • SNR signal-to-noise ratio
  • SINR signal-to-interference-plus-noise ratio
  • Channel reciprocity is a method of estimating a downlink (DL) channel through a sounding procedure of an uplink (UL) channel.
  • the UL MU transmission of the STA (joint transmission NDP) is performed using channel reciprocity.
  • Frame a method for performing estimation of DL channels of S-APs will be described.
  • the M-AP may transmit a joint transmission NDP feedback trigger frame to the first to third S-APs.
  • the M-AP may receive a joint transmission NDP feedback frame in response to the joint transmission NDP feedback trigger frame from the first to third S-APs.
  • the M-AP may select the optimal S-AP for the joint transmission based on the joint transmission NDP feedback frame.
  • the joint transmission NDP feedback frame may include channel information in which individual values of channel estimation performed between the first to third S-APs and the STA are combined into one.
  • the optimal S-AP for the joint transmission may be selected as the first and second S-APs based on the channel information combined into the one.
  • the M-AP may transmit a joint transmission selection frame to the first and second S-APs.
  • the joint transmission selection frame is based on data to be used for the joint transmission, antennas to be used by the first and second S-APs, the number of streams supported by the first and second S-APs, and modulation and coding scheme (MCS). Information.
  • MCS modulation and coding scheme
  • the data can be shared between the M-AP and the first and second S-APs.
  • the data may be transmitted to the STA by the first and second S-APs. That is, joint transmission by multiple APs may be performed through the above-described procedure.
  • the joint transmission NDP frame includes only a Long Training Field (LTF) for one stream. Can be.
  • LTF Long Training Field
  • MIMO multi-input multi-output
  • the joint transmission NDP frame may be transmitted to the STA by the first and second S-APs.
  • the technical features of the present specification described above can be applied to various application or business models.
  • the above-described technical features may be applied for wireless communication in a device supporting artificial intelligence (AI).
  • AI artificial intelligence
  • Machine learning refers to the field of studying the methodology to define and solve various problems in the field of artificial intelligence. do.
  • Machine learning is defined as an algorithm that improves the performance of a job through steady experience.
  • An artificial neural network is a model used in machine learning, and may refer to an overall model having a problem-solving ability, composed of artificial neurons (nodes) forming a network through synaptic coupling.
  • the artificial neural network may be defined by a connection pattern between neurons of different layers, a learning process for updating model parameters, and an activation function that generates output values.
  • the artificial neural network may include an input layer, an output layer, and optionally one or more hidden layers. Each layer contains one or more neurons, and the artificial neural network can include neurons and synapses connecting neurons. In an artificial neural network, each neuron may output a function value of an input function input through a synapse, a weight, and an active function for bias.
  • the model parameter means a parameter determined through learning, and includes weights of synaptic connections and bias of neurons.
  • the hyperparameter means a parameter that must be set before learning in a machine learning algorithm, and includes learning rate, number of iterations, mini-batch size, initialization function, and the like.
  • the purpose of training an artificial neural network can be seen as determining model parameters that minimize the loss function.
  • the loss function can be used as an index for determining an optimal model parameter in the learning process of an artificial neural network.
  • Machine learning can be classified into supervised learning, unsupervised learning, and reinforcement learning according to the learning method.
  • Supervised learning refers to a method of training an artificial neural network while a label for training data is given, and a label is a correct answer (or a result value) that the artificial neural network must infer when the training data is input to the artificial neural network.
  • Unsupervised learning may refer to a method of training an artificial neural network without a label for learning data.
  • Reinforcement learning may mean a learning method in which an agent defined in a certain environment is trained to select an action or a sequence of actions to maximize cumulative reward in each state.
  • Machine learning implemented as a deep neural network (DNN) that includes a plurality of hidden layers among artificial neural networks is also referred to as deep learning (deep learning), and deep learning is part of machine learning.
  • DNN deep neural network
  • machine learning is used to mean deep learning.
  • a robot can mean a machine that automatically handles or acts on a task given by its own capabilities.
  • a robot having a function of recognizing the environment and performing an operation by determining itself can be referred to as an intelligent robot.
  • Robots can be classified into industrial, medical, household, and military according to the purpose or field of use.
  • the robot may be provided with a driving unit including an actuator or a motor to perform various physical operations such as moving a robot joint.
  • the movable robot includes a wheel, a brake, a propeller, and the like in the driving unit, so that it can travel on the ground or fly in the air through the driving unit.
  • Augmented reality refers to virtual reality (VR), augmented reality (AR), and mixed reality (MR).
  • VR technology provides real-world objects or backgrounds only as CG images
  • AR technology provides CG images made virtually on real objects
  • MR technology is a computer that mixes and combines virtual objects in the real world.
  • MR technology is similar to AR technology in that it shows both real and virtual objects.
  • a virtual object is used as a complement to a real object, whereas in MR technology, there is a difference in that a virtual object and a real object are used with equal characteristics.
  • HMD Head-Mount Display
  • HUD Head-Up Display
  • mobile phone tablet PC, laptop, desktop, TV, digital signage, etc. It can be called.

Abstract

La présente invention concerne un procédé et un dispositif destinés à réaliser une transmission conjointe dans un système LAN sans fil. Plus précisément, un M-AP sélectionne des premier à troisième S-AP qui doivent participer à la transmission conjointe. Le M-AP gère une liaison avec les premier à troisième S-AP afin de partager des premières informations entre les premier à troisième S-AP. Le M-AP réalise une transmission conjointe vers une STA par l'intermédiaire des premier à troisième S-AP sur la base des premières informations.
PCT/KR2019/014454 2018-10-30 2019-10-30 Procédé et dispositif destinés à réaliser une transmission conjointe dans un système lan sans fil WO2020091412A1 (fr)

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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2022205460A1 (fr) * 2021-04-02 2022-10-06 Oppo广东移动通信有限公司 Procédé de communication sans fil, dispositif de station et dispositif de point d'accès

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR20150082558A (ko) * 2012-11-08 2015-07-15 인터디지탈 패튼 홀딩스, 인크 무선 근거리 네트워크들에서 균일한 다수의 액세스 포인트들의 커버리지에 대한 매체 액세스 제어를 위한 방법 및 장치
KR20150117218A (ko) * 2014-04-08 2015-10-19 한국전자통신연구원 중첩된 bss 환경에서 ap간 협력 통신을 위한 프로토콜
KR101656999B1 (ko) * 2015-05-11 2016-09-12 금오공과대학교 산학협력단 무선 랜의 협력 통신 방법 및 시스템
US20180102816A1 (en) * 2013-09-06 2018-04-12 Electronics And Telecommunications Research Institute Communication method using interference alignment in wireless lan

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR20150082558A (ko) * 2012-11-08 2015-07-15 인터디지탈 패튼 홀딩스, 인크 무선 근거리 네트워크들에서 균일한 다수의 액세스 포인트들의 커버리지에 대한 매체 액세스 제어를 위한 방법 및 장치
US20180102816A1 (en) * 2013-09-06 2018-04-12 Electronics And Telecommunications Research Institute Communication method using interference alignment in wireless lan
KR20150117218A (ko) * 2014-04-08 2015-10-19 한국전자통신연구원 중첩된 bss 환경에서 ap간 협력 통신을 위한 프로토콜
KR101656999B1 (ko) * 2015-05-11 2016-09-12 금오공과대학교 산학협력단 무선 랜의 협력 통신 방법 및 시스템

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
BROADCOM: "Constrained Distributed MU-MIMO", IEEE 802.11-18/1439R0, 4 September 2018 (2018-09-04), XP055705806 *

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2022205460A1 (fr) * 2021-04-02 2022-10-06 Oppo广东移动通信有限公司 Procédé de communication sans fil, dispositif de station et dispositif de point d'accès

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