Triggering distributed MIMO communications in a cluster of wireless nodes

Abstract

Various aspects of the present disclosure relate to distributed multiple-input multiple-output (MIMO) communications, such as triggering distributed MIMO communications, coordinated beamforming, or joint MIMO within a cluster of wireless nodes. In some aspects, distributed MIMO is used to support communications within a cluster of wireless nodes (e.g., access points). A distributed MIMO scheduling scheme, as taught herein, is used to schedule wireless nodes (e.g., access points and / or stations) operating within the cluster. For example, a selected station can be triggered to communicate with a corresponding access point.

Description

[0001] This application is a divisional application of the Chinese patent application with the application date of March 9, 2018, application number 201880016987.2 (international application number PCT / US2018 / 021854), and invention name “Triggering distributed MIMO communication in a wireless node cluster”.

[0002] CROSS-REFERENCE TO RELATED APPLICATIONS

[0003] This application claims priority to and the benefit of Provisional Application No. 62 / 601,116 filed in the U.S. Patent and Trademark Office on March 11, 2017, Provisional Application No. 62 / 471,954 filed in the U.S. Patent and Trademark Office on March 15, 2017, and Non-Provisional Application No. 15 / 916,195 filed in the U.S. Patent and Trademark Office on March 8, 2018, the entire contents of which are incorporated herein by reference. Technical Field

[0004]

[0014] Various aspects described herein relate to wireless communications, and particularly, but not exclusively, to distributed multiple-input, multiple-output (MIMO) communications for clusters of wireless nodes (e.g., access points). Background Art

[0005] Some types of wireless communication devices employ multiple antennas to provide higher levels of performance than devices using a single antenna. One example is a Multiple-Input Multiple-Output (MIMO) system, in which a transmitting device uses multiple transmit antennas to send signals to a receiving device with one or more receive antennas. Another example is a millimeter wave (mmW) system, in which multiple antennas are used for beamforming (e.g., in the 30 GHz, 60 GHz, and other ranges).

[0006] Figure 1 A communication system 100 is illustrated in which a mmW access point (AP) 102 communicates with a first mmW station (STA) 104 and a second mmW STA 106 via different beamforming directions. The mmW AP 102 can communicate via any one of a plurality of directional beams, as indicated by beam set 108. The first mmW STA 104 can communicate via any one of a plurality of directional beams, as indicated by beam set 110. The second mmW STA 106 can communicate via any one of a plurality of directional beams, as indicated by beam set 112. For example, the AP 102 can communicate with the first mmW STA 104 via a first beamforming direction 114 and with the second mmW STA 106 via a second beamforming direction 116.

[0007] In practice, different devices will transmit (e.g., send beamformed transmissions) on shared communication resources. However, even when the signals are beamformed, a transmission by one device on a particular communication resource can interfere with the communication of another device on the same communication resource. Therefore, efficient techniques for sharing communication resources are needed. Summary of the Invention

[0008] The following is a brief overview of some aspects of the present disclosure to provide a basic understanding of these aspects. This overview is not an exhaustive overview of all contemplated features of the present disclosure, and is neither intended to identify key or critical elements of all aspects of the present disclosure nor to delineate the scope of any or all aspects of the present disclosure. Its sole purpose is to present various concepts of some aspects of the present disclosure in a simplified form as a prelude to the more detailed description that will be presented later.

[0009] In some aspects, the present disclosure provides an apparatus configured for communication, the apparatus comprising a processing system and an interface. The interface is configured to obtain a communication schedule identifying a plurality of first wireless nodes in a cluster of wireless nodes for collectively serving a plurality of second wireless nodes via distributed multiple-input multiple-output (MIMO) communication, wherein the communication schedule specifies that a first second wireless node in the plurality of second wireless nodes communicate with a first first wireless node in the plurality of first wireless nodes during a specific time slot, and a second second wireless node in the plurality of second wireless nodes communicate with a second first wireless node in the plurality of first wireless nodes during a specific time slot. The processing system is configured to generate a frame to trigger distributed MIMO communication by the plurality of second wireless nodes, wherein generation of the frame is based on the communication schedule. The interface is further configured to output the frame for transmission.

[0010] In some aspects, the present disclosure provides a method for communication of an apparatus. The method includes: obtaining a communication schedule identifying a plurality of first wireless nodes in a cluster of wireless nodes for collectively serving a plurality of second wireless nodes via distributed multiple-input multiple-output (MIMO) communication, wherein the communication schedule specifies that a first second wireless node in the plurality of second wireless nodes communicate with a first first wireless node in the plurality of first wireless nodes during a specific time slot, and a second second wireless node in the plurality of second wireless nodes communicate with a second first wireless node in the plurality of first wireless nodes during a specific time slot; generating a frame to trigger the distributed MIMO communication by the plurality of second wireless nodes, wherein the generation of the frame is based on the communication schedule; and outputting the frame for transmission.

[0011] In some aspects, the present disclosure provides an apparatus configured for communication. The apparatus includes: means for obtaining a communication schedule identifying a plurality of first wireless nodes in a cluster of wireless nodes for collectively serving a plurality of second wireless nodes via distributed multiple-input multiple-output (MIMO) communication, wherein the communication schedule specifies that a first second wireless node in the plurality of second wireless nodes communicate with a first first wireless node in the plurality of first wireless nodes during a specific time slot, and a second second wireless node in the plurality of second wireless nodes communicate with a second first wireless node in the plurality of first wireless nodes during a specific time slot; means for generating a frame to trigger distributed MIMO communication by the plurality of second wireless nodes, wherein the generation of the frame is based on the communication schedule; and means for outputting the frame for transmission.

[0012] In some aspects, the present disclosure provides a wireless node. The wireless node includes a processing system, a receiver, and a transmitter. The receiver is configured to receive a communication schedule identifying a plurality of first wireless nodes in a cluster of wireless nodes for collectively serving a plurality of second wireless nodes via distributed multiple-input multiple-output (MIMO) communication, wherein the communication schedule specifies that a first second wireless node in the plurality of second wireless nodes communicate with a first first wireless node in the plurality of first wireless nodes during a specific time slot, and a second second wireless node in the plurality of second wireless nodes communicate with a second first wireless node in the plurality of first wireless nodes during a specific time slot. The processing system is configured to generate a frame to trigger distributed MIMO communication by the plurality of second wireless nodes, wherein generation of the frame is based on the communication schedule. The transmitter is configured to transmit the frame.

[0013] In some aspects, the present disclosure provides a computer-readable medium (e.g., a non-transitory computer-readable medium) storing computer-executable code, the computer-executable code including code for: obtaining a communication schedule identifying a plurality of first wireless nodes in a cluster of wireless nodes for collectively serving a plurality of second wireless nodes via distributed multiple-input multiple-output (MIMO) communication, wherein the communication schedule specifies that a first second wireless node in the plurality of second wireless nodes communicate with a first first wireless node in the plurality of first wireless nodes during a specific time slot, and a second second wireless node in the plurality of second wireless nodes communicate with a second first wireless node in the plurality of first wireless nodes during a specific time slot; generating a frame to trigger distributed MIMO communication by the plurality of second wireless nodes, wherein the generation of the frame is based on the communication schedule; and outputting the frame for transmission.

[0014] These and other aspects of the present disclosure will be more fully understood after reading the following detailed description. After studying the description of the specific implementation of the present disclosure below in conjunction with the accompanying drawings, other aspects, features and implementations of the present disclosure will be obvious to those of ordinary skill in the art. Although the features of the present disclosure may be discussed below with respect to certain implementations and drawings, all implementations of the present disclosure may include one or more of the advantageous features discussed herein. In other words, although one or more implementations may be discussed as having certain advantageous features, one or more of such features may also be used according to the various implementations of the present disclosure discussed herein. In a similar manner, although some implementations may be discussed below as device, system or method implementations, it should be understood that such implementations can be implemented in various devices, systems, and methods. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The accompanying drawings are presented to aid in describing the aspects of the disclosure and are provided solely for illustration of the aspects and not limitation thereof.

[0016] Figure 1 An example of a wireless communication system is illustrated in which aspects of the present disclosure may be employed.

[0017] Figure 2 Another example of a wireless communication system is illustrated in which aspects of the present disclosure may be employed.

[0018] Figure 3 is an example illustrating access point clustering according to some aspects of the present disclosure.

[0019] Figure 4 An example of downlink scheduling in accordance with some aspects of the present disclosure is illustrated.

[0020] Figure 5 is another example illustrating access point clustering according to some aspects of the present disclosure.

[0021] Figure 6

[0014] Illustrated are examples of uplink scheduling according to some aspects of the present disclosure.

[0022] Figure 7 An example of downlink signal measurement signaling using beacons is illustrated in accordance with some aspects of the present disclosure.

[0023] Figure 8 An example of downlink signal measurement signaling using dedicated sequences in accordance with some aspects of the present disclosure is illustrated.

[0024] Figure 9

[0014] An example of uplink signal measurement signaling using block acknowledgments in accordance with some aspects of the present disclosure is illustrated.

[0025] Figure 10

[0014] An example of uplink signal measurement signaling using trigger frames in accordance with some aspects of the present disclosure is illustrated.

[0026] Figure 11

[0014] An example of downlink coordinated beamforming sounding in which access points independently send null data packet announcements in accordance with some aspects of the present disclosure is illustrated.

[0027] Figure 12

[0014] An example of downlink coordinated beamforming sounding in which a master access point sends a null data packet announcement for all access points is illustrated in accordance with some aspects of the present disclosure.

[0028] Figure 13 An example of a multiple basic service set sounding scheduling frame is illustrated in accordance with some aspects of the present disclosure.

[0029] Figure 14 An example of aggregating null data packet announcements in accordance with some aspects of the present disclosure is illustrated.

[0030] Figure 15 Illustrated is an example of sending a scheduling decision in a sounding trigger and scheduling frame at the beginning of an uplink sounding per base station serving set, in accordance with some aspects of the present disclosure.

[0031] Figure 16 Illustrated is an example of sending a query frame to solicit input from a participant access point in accordance with some aspects of the present disclosure.

[0032] Figure 17 An example of a scheduler polling potential stations in a participant basic service set for per-station information is illustrated in accordance with aspects of the present disclosure.

[0033] Figure 18 Illustrated is an example of an access point advertising the input of its basic service set in a transmitted frame in accordance with some aspects of the present disclosure.

[0034] Figure 19 An example of stations advertising their per-station information in transmitted frames is illustrated in accordance with some aspects of the present disclosure.

[0035] Figure 20 Illustrated is an example of sending a multi-access point trigger to initiate downlink coordinated beamforming transmissions in accordance with some aspects of the present disclosure.

[0036] Figure 21 Illustrated is an example of signaling in which an initiator node maintains long transmission opportunities for a sequence of downlink coordinated beamforming transmissions in accordance with some aspects of the present disclosure.

[0037] Figure 22 Illustrated is an example of signaling in which subsequent multi-access point trigger frames are ignored, in accordance with some aspects of the present disclosure.

[0038] Figure 23 An example of downlink coordinated beamforming scheduling involving sending a query frame to solicit candidate station information from a set of access points is illustrated in accordance with some aspects of the present disclosure.

[0039] Figure 24 Illustrated is an example of downlink coordinated beamforming scheduling in which each access point advertises candidate station information in frames transmitted by the access point, in accordance with some aspects of the present disclosure.

[0040] Figure 25 An example of downlink coordinated beamforming scheduling in which each access point advertises candidate station information during a defined time period is illustrated in accordance with some aspects of the present disclosure.

[0041] Figure 26 An example of downlink coordinated beamforming cascade scheduling in accordance with some aspects of the present disclosure is illustrated.

[0042] Figure 27 Illustrated is an example of signaling in which each access point sends an individual trigger frame to trigger uplink transmissions from its station(s) in accordance with some aspects of the present disclosure.

[0043] Figure 28 Illustrated is an example of signaling in which an access point sends a trigger frame on the same resources in accordance with some aspects of the present disclosure.

[0044] Figure 29

[0014] An example of sending a scheduling decision in a scheduling frame in accordance with some aspects of the present disclosure is illustrated.

[0045] Figure 30 An example is illustrated in which a scheduling frame directly triggers signaling for all scheduled stations in accordance with some aspects of the present disclosure.

[0046] Figure 31 Illustrated is an example of signaling in which an initiating node maintains long transmission opportunities for a sequence of uplink coordinated beamforming transmissions in accordance with some aspects of the present disclosure.

[0047] Figure 32 An example of signaling in which an acknowledgement by each access point is combined with a trigger frame is illustrated in accordance with some aspects of the present disclosure.

[0048] Figure 33 An example of uplink coordinated beamforming scheduling involving sending a query frame to solicit candidate station information from a set of access points is illustrated in accordance with some aspects of the present disclosure.

[0049] Figure 34 An example is illustrated of a scheduler polling potential stations within range of the scheduler to obtain per-station information in accordance with some aspects of the present disclosure.

[0050] Figure 35

[0014] An example of uplink coordinated beamforming scheduling in which each access point advertises candidate station information in frames transmitted by the access point is illustrated in accordance with some aspects of the present disclosure.

[0051] Figure 36 An example of uplink coordinated beamforming scheduling in which each station advertises its per-station information in station-transmitted frames is illustrated in accordance with some aspects of the present disclosure.

[0052] Figure 37 Another example of access point clustering in accordance with some aspects of the present disclosure is illustrated.

[0053] Figure 38 An example of uplink coordinated beamforming cascade scheduling in accordance with some aspects of the present disclosure is illustrated.

[0054] Figure 39 An example of a composite downlink coordinated beamforming frame is illustrated in accordance with some aspects of the present disclosure.

[0055] Figure 40 An example of a composite downlink orthogonal frequency division multiple access frame is illustrated in accordance with some aspects of the present disclosure.

[0056] Figure 41 Illustrated are examples of downlink multiple basic service set frames in accordance with some aspects of the present disclosure.

[0057] Figure 42 Illustrated are examples of frames with a common scheduling preamble in accordance with some aspects of the present disclosure.

[0058] Figure 43 is another example illustrating access point clustering according to some aspects of the present disclosure.

[0059] Figure 44 An example comparison of multi-user carrier sense multiple access, coordinated beamforming, and joint MIMO is illustrated.

[0060] Figure 45 An example of a wireless communication system is illustrated in which aspects of the present disclosure may be employed.

[0061] Figure 46 is a functional block diagram of an example apparatus that may be employed within a wireless communication system in accordance with some aspects of the present disclosure.

[0062] Figure 47 It is available in Figure 46 A functional block diagram of example components for transmitting wireless communications in an apparatus.

[0063] Figure 48 It is available in Figure 46A functional block diagram of example components in an apparatus for receiving wireless communications.

[0064] Figure 49 is a functional block diagram of an example apparatus according to some aspects of the present disclosure.

[0065] Figure 50 is a flow diagram of an example process for identifying nodes for a null operation according to some aspects of the present disclosure.

[0066] Figure 51 is a flow chart of an example process for providing an indication based on signal measurement information according to some aspects of the present disclosure.

[0067] Figure 52 is a flow diagram of an example sounding scheduling process according to some aspects of the present disclosure.

[0068] Figure 53 is a flow diagram of an example scheduling process according to some aspects of the present disclosure.

[0069] Figure 54 is a flow diagram of an example of a scheduled communication process according to some aspects of the present disclosure.

[0070] Figure 55 is a flow diagram of an example process for triggering communications according to some aspects of the present disclosure.

[0071] Figure 56 is a flow diagram of another example of a scheduled communication process according to some aspects of the present disclosure.

[0072] Figure 57 is a simplified block diagram of several sample aspects of an apparatus configured with functionality according to some aspects of the present invention.

[0073] Figure 58 is a simplified block diagram of several sample aspects of memory configured with code according to some aspects of the present invention. DETAILED DESCRIPTION

[0074] The various aspects of the present disclosure are described below. It should be apparent that the teachings herein can be embodied in a variety of forms, and any specific structure, function, or both disclosed herein are merely representative. Based on the teachings herein, it will be appreciated by those skilled in the art that the aspects disclosed herein can be implemented independently of any other aspect and two or more of these aspects can be combined in various ways. For example, any number of aspects set forth herein can be used to implement a device or practice a method. In addition, other structures, functions, or structures and functions that are supplementary to or different from one or more aspects set forth herein can be used to implement such a device or practice such a method. Furthermore, an aspect can include at least one element of a claim. For example, a method of communication may include: obtaining a communication schedule identifying multiple first wireless nodes in a wireless node cluster for jointly serving multiple second wireless nodes via distributed multiple-input multiple-output (MIMO) communication, wherein the communication schedule specifies that a first second wireless node among the multiple second wireless nodes communicates with a first first wireless node among the multiple first wireless nodes during a specific time slot, and a second second wireless node among the multiple second wireless nodes communicates with a second first wireless node among the multiple first wireless nodes during a specific time slot; generating a frame to trigger distributed MIMO communication by the multiple second wireless nodes, wherein the generation of the frame is based on the communication schedule; and outputting the frame for transmission.

[0075] Wireless MIMO systems can use multiple transmit antennas to provide beamforming-based signal transmission. Typically, the phase (and optionally the amplitude) of beamforming-based signals transmitted from different antennas is adjusted so that the resulting signal power is focused on the receiving device (e.g., an access terminal).

[0076] Wireless MIMO systems can support communication to a single user at a time or to multiple users concurrently. Transmission to a single user (e.g., a single receiving device) is often referred to as single-user MIMO (SU-MIMO), while concurrent transmission to multiple users is often referred to as multi-user MIMO (MU-MIMO).

[0077] MIMO can be used in wireless local area networks (WLANs) that support IEEE 802.11ax or some other 802.11-based standards. An access point (e.g., a base station) in an 802.11-based MIMO system uses multiple antennas for data transmission and reception, while each user STA (which may be referred to as user equipment) uses one or more antennas. The access point communicates with the STA via a forward link channel and a reverse link channel. In some aspects, a downlink (DL) channel refers to a communication channel from the access point's transmit antenna to the STA's receive antenna, while an uplink (UL) channel refers to a communication channel from the STA's transmit antenna to the access point's receive antenna. The downlink and uplink may be referred to as a forward link and a reverse link, respectively.

[0078] Because precoding (e.g., beamforming) is employed to direct transmissions toward the receive antennas, a MIMO channel corresponding to a transmission from a set of transmit antennas to a receive antenna is referred to as a spatial stream. Thus, in some aspects, each spatial stream corresponds to at least one dimension. Thus, MIMO systems provide improved performance (e.g., higher throughput and / or greater reliability) by utilizing the additional dimensionality provided by these spatial streams.

[0079] Various aspects of the present disclosure relate to distributed MIMO communications, which may relate to, for example, coordinated beamforming (COBF), joint MIMO, multi-base station service set (multi-BSS) joint communications, or orthogonal frequency division multiple access (OFDMA) communications or be implemented using them. In some aspects, distributed MIMO is used to support communications in a cluster of access points. For example, a distributed MIMO scheduling scheme as taught herein may be used to schedule COBF transmissions by access points and / or stations operating within a cluster, where blanking is scheduled as needed to mitigate interference between these devices. For purposes of illustration, various aspects of the present invention may be described in the context of COBF or another form of distributed MIMO communications. However, it should be understood that these teachings may be equally applicable to general distributed MIMO communications and / or other forms of communications. Similarly, various aspects of the present disclosure may be described in the context of UL and / or DL ​​communications. It should be understood that these teachings may be equally applicable to other forms of communications (e.g., peer-to-peer communications, etc.).

[0080] Access points (APs) that do not utilize all of their dimensions (e.g., antennas) for communication with the STAs they serve may be grouped for coordinated beamforming. In some aspects, coordinated beamforming can fully utilize the unused AP dimensions by grouping APs with underutilized dimensions together in the same time slot. In this case, the unused AP dimensions are used to form nulls for stations (STAs) of other APs (e.g., other basic service sets, BSSs) of the beamforming group to mitigate interference caused by transmissions from clustered devices during that time slot. For example, nulls can be formed by configuring beamforming parameters (e.g., phase) for a set of antennas to reduce interference caused by a nulled device at another device or to reduce interference from another device at a nulled device.

[0081] Figure 2 A wireless communication system 200 is illustrated in which a first device 202 (e.g., an AP) and a second device 204 (e.g., an AP) are part of a cluster (e.g., an AP cluster). An optional third device 206 (e.g., a scheduling entity, a central controller, or some other entity) is also shown. The first device 202 serves a fourth device 208 (e.g., a STA). The second device 204 serves a fifth device 210 (e.g., a STA). In other scenarios, a different number of devices may be associated with the cluster.

[0082] Figure 2 Each device in the embodiment includes a respective transceiver 212, 214, 216, 218, or 220 for wireless communication and / or wired communication. The first device 202 includes a transceiver 212 for communicating via a wireless communication medium. The second device 204 includes a transceiver 214 for communicating via a wireless communication medium. The fourth device 208 includes a transceiver 218 for communicating via a wireless communication medium. The fifth device 210 includes a transceiver 220 for communicating via a wireless communication medium. The third device 206 may include a transceiver 216 for communicating via a wireless communication medium. Alternatively or additionally, communications to or from the third device 206 may be over a wired medium (e.g., a wired backhaul).

[0083] The first device 202 and the second device 204 include functionality for scheduling distributed MIMO transmissions and sending and receiving information for creating a schedule. To this end, the first device 202 includes functionality 222 for distributed MIMO scheduling and signaling control, and the second device 204 includes functionality 224 for distributed MIMO scheduling and signaling control. For example, the second device 204 (e.g., an AP that is a leader or group leader of a cluster) may receive dimension information and station information from the first device 202 (e.g., an AP) to determine how to schedule distributed MIMO transmissions for the cluster. In some implementations, the third device may include functionality 226 for distributed MIMO scheduling. For example, the third device 206 may receive dimension information and station information from the first device 202 and the second device 204 to determine how to schedule distributed MIMO transmissions for the cluster. The exchange of this scheduling-related information and other scheduling-related information is performed by Figure 2 The communication code elements 236, 238 and 240 are represented.

[0084] Any of the first device 202, the second device 204, and the third device 206 may obtain information from the fourth device 208 and the fifth device 210 to facilitate distributed MIMO scheduling. To this end, the fourth device 208 includes functionality 228 for measurement operations and functionality 232 for providing input for scheduling. In addition, the fifth device 210 includes functionality 230 for measurement operations and functionality 234 for providing input for scheduling. This information and other information between the first device 202, the second device 204, the fourth device 208, and the fifth device 210 and the scheduled distributed MIMO transmission are communicated by Figure 2 The communication code elements 242 and 244 are represented.

[0085] I. Overview

[0086] In some aspects, the present disclosure relates to over-the-air (OTA) scheduling and communication for clusters that may have unplanned, unmanaged AP deployments (e.g., dense apartment buildings). In such deployments, there may be no central controller or wired inter-AP communication. However, legacy APs may be present. Scheduling and communication can be summarized as four steps for operations associated with DL data transmission and three steps for operations associated with UL data transmission.

[0087] IA.DL Steps

[0088] Initially referring to the DL, in step 1, an AP forms or joins a cluster. In some cases, a cluster may remain static for a relatively long period of time (e.g., hours or days). An AP that is not currently in a cluster may discover compatible standalone APs with which to form a cluster, or an AP may discover an existing cluster within range that the AP can join. Standalone APs and devices (e.g., APs) in the cluster may broadcast AP information and cluster information on their operating channels. Step 1 is not discussed in detail in the following discussion.

[0089] Step 2 involves identifying, for each BSS of the cluster, STAs in the BSS that do not need to be nulled (referred to herein as reused STAs or InBSS STAs) and STAs that need to be nulled (referred to herein as non-reused STAs or OBSS STAs). This STA identification may be repeated (e.g., once per second or at other times) to track any changes in path loss (PL).

[0090] Each AP selects its InBSS STAs to report measured received signal strength indicators (RSSIs) or some other channel quality or signal measurement from all APs in the cluster. Based on these measurements, the AP determines the identity of the AP that will need to perform blanking operations for all of these STAs. In other words, each AP determines the blanking OBSS AP ID on a per-STA basis. Measurements can be based on beacons, null data packet (NDP) soundings, dedicated measurement sequences, or some other form of signaling.

[0091] After the measurement phase, the AP can send the results to the scheduler (e.g., the leader AP, such as a cluster head) or to all APs in the cluster. The scheduler or the APs forming the cluster can then use this information to schedule sounding in step 3 or for DL ​​COBF transmission (Tx) in step 4. Alternatively, the AP can send the results as part of the reported candidate STA information to these entities in steps 3 and 4. These and other aspects of step 2 for DL ​​will be discussed in detail in Section IV-A below.

[0092] Step 3 involves DL COBF sounding scheduling and transmission. These operations may be repeated (e.g., every 20 milliseconds). For scheduling, the leader AP may collect candidate STA information from each AP in the cluster, make a sounding scheduling decision based on this information, and announce the sounding scheduling decision. This decision may include the identifiers (IDs) of the participating APs (AP IDs), the NDP order or configuration, the IDs of the STAs to measure the NDPs of each AP, and the beamforming report (BFRP) configuration of the STAs.

[0093] In some cases, the scheduling decision may be based simply on the results from step 2. For example, the scheduling decision may be to schedule only certain STAs (eg, those that need to be blanked by at least one AP) to measure the NDP.

[0094] Once the sounding is scheduled, the sounding transmission is performed. The participating AP executes the sounding sequence based on the sounding decision. These and other aspects of step 3 for DL ​​will be discussed in detail in the subsequent section V.

[0095] Step 4 involves scheduling and transmitting DL COBF data transmissions. These operations can be repeated (e.g., every 4 ms). For scheduling, the AP that wins channel access can collect candidate STA information from each AP in the cluster, make a DL data transmission scheduling decision based on this information, and announce the DL data transmission scheduling decision. This decision may include, for example, the ID of the scheduled STA, the stream number (#) per STA (number of streams per station), the ID of the blanking OBSS AP per STA, the DL COBF transmission duration and bandwidth (BW), and the UL acknowledgment (ACK) resource per STA. This decision can use the results from step 2 to ensure that the STA is blanked by the appropriate OBSS AP if necessary and that the scheduled STA reports its BFRP to all its blanking APs in step 3.

[0096] Once the DL COBF data transmission is scheduled, the DL COBF data transmission is performed. The participating AP performs the DL data transmission based on the transmission scheduling decision. These and other aspects of step 4 for DL ​​will be discussed in detail in the subsequent section VI.

[0097] IB.UL Steps

[0098] Referring now to the UL, step 1 here is the same as step 1 discussed above for the DL.

[0099] As in step 2 for the DL, step 2 for the UL involves identifying reused and non-reused STAs for each BSS in the cluster. Similarly, this STA identification can be repeated (e.g., once per second or at some other time) to track any changes in path loss (PL). However, the way STAs are identified is slightly different from that for the UL.

[0100] For the UL, each AP estimates the UL RSSI (or some other channel quality or signal measurement) caused by each of its InBSS STAs at each AP in the cluster. The AP then determines the ID of the OBSS AP that will need to null the STA in the UL. This STA identification can be combined with the identification for the DL (e.g., step 2 for the DL).

[0101] After the measurement phase, the AP can send the results to the scheduler (e.g., the leader AP, such as a cluster head) or to all APs in the cluster. The scheduler or the APs forming the cluster can then use this information to schedule UL COBF transmissions in step 3. Alternatively, the AP can send the results to these entities as part of the reported candidate STA information in step 3. These and other aspects of step 2 for the UL will be discussed in detail in Section IV-B below.

[0102] Step 3 involves scheduling and transmitting UL COBF data transmissions (e.g., every 4 ms or at other intervals). For scheduling, the AP that wins channel access collects candidate STA information from each AP in the cluster, makes a UL data transmission scheduling decision based on this information, and announces the UL data transmission scheduling decision. This decision may include, for example, the ID of the scheduled STA, the number of streams per STA, the ID of the blanking OBSS AP per STA, the UL COBF transmission duration and bandwidth, and the DL ACK resources per AP. This decision can use the results from step 2 to ensure that the STA is blanked in the UL by the appropriate OBSS AP, if necessary.

[0103] The scheduling decision may also include resource allocation for each AP's trigger frame (TF). The AP's TF will trigger the AP's STAs to perform UL COBF transmissions.

[0104] Once the UL COBF data transmission is scheduled, the UL COBF data transmission is performed. The participating AP performs the data transmission based on the UL transmission scheduling decision. These and other aspects of step 3 for the UL will be discussed in detail in the subsequent section VII.

[0105] Now refer to Figure 3-44 The above steps for distributed MIMO scheduling and transmission according to the teachings of this document are described in more detail. For the purpose of explanation, Figure 3-42 Various concepts are explained in the context of the coordinated beamforming (COBF) architecture. Figure 43 and 44 As discussed, for example, the teachings herein are applicable to other types of distributed MIMO (eg, joint MIMO, etc.).

[0106] II. DL COBF Scheduling Example

[0107] Figure 3An exemplary wireless communication system 300 is illustrated in which four APs (AP1-AP4) form a group for COBF transmission. In this example, each AP has two STAs in its basic service set (BSS). The first AP, AP1, serves STAs S1-1 and S1-2, the second AP, AP2, serves STAs S2-1 and S2-2, the third AP, AP3, serves STAs S3-1 and S3-2, and the fourth AP, AP4, serves STAs S4-1 and S4-2. Each AP has at least five antennas (i.e., five dimensions). Each STA has a single antenna. Other configurations may be used in other scenarios.

[0108] In some aspects, there may be two categories of STAs. The first category of STAs does not require blanking by its serving AP and may be referred to as InBSS STAs (or IBSS STAs). The second category of STAs requires blanking by at least one AP other than its serving AP and may be referred to as Out-BSS STAs (OBSS STAs).

[0109] InBSS STA( Figure 3 The boxes with thicker lines in the figure have sufficient signal to interference and noise ratio (SINR) to be served simultaneously without being nulled by any overlapping BSS (OBSS) APs in the beamforming group. Figure 3 The InBSS STAs in are designated STAS1-2, S2-2, S3-2 and S4-2.

[0110] OBSS STA( Figure 3 The boxes with thinner lines in the figure are those STAs where OBSS AP transmissions may significantly reduce the SINR of the STA. According to the teachings herein, an OBSS STA may be blanked by at least one OBSS AP. Figure 3 The OBSS STAs in the STA are designated as STAs S1-1, S2-1, S3-1, and S4-1.

[0111] exist Figure 3 In the example shown in FIG1 , one STA in each BSS (the box with thinner lines) is relatively close to three OBSS APs and therefore may require blanking from these OBSS APs. For example, STA S1-1 may require blanking from the second AP AP2, the third AP AP3, and the fourth AP AP4. Other STAs in the BSS (the boxes with thicker lines) are farther away from the three OBSS APs and therefore may not require blanking from these OBSS APs. For example, STA S1-2 may not require blanking signals from the second AP AP2, the third AP AP3, and the fourth AP AP4.

[0112] According to the teachings herein, in a given coordinated beamforming transmission time slot, an AP may serve at least one InBSS STA and / or at least one OBSS STA. Figure 4 Downlink coordinated beamforming (DL-COBF) scheduling 400, Figure 4 DL COBF transmissions by a first AP AP1, a second AP AP2, a third AP AP3, and a fourth AP AP4 are shown. Each AP uses X dimensions to serve its X selected IBSS STAs (in Figure 3 Each AP uses its remaining Y dimensions to serve or empty Y selected OBSS STAs (in Figure 3 In the example, Y=1).

[0113] In which each AP has five dimensions Figure 3 In DL COBF scheduling, each AP can use two dimensions to serve its two STAs and use the remaining three dimensions to form nulls for the three OBSS STAs that need to be nulled. For example, the first AP AP1 can serve STAs S1-1 and S1-2 in its BSS and form three nulls for the three OBSS STAs (STAS2-1, S3-1, and S4-1) that need to be nulled.

[0114] III. UL Coordinated Beamforming

[0115] UL COBF scheduling example will refer to Figure 5 As discussed in the wireless communication system 500. Figure 3 In the example, Figure 5 Each AP (AP1, AP2, AP3, and AP4) has at least five antennas (five dimensions) and uses two dimensions to receive simultaneously from its two InBSS STAs in the UL. Figure 6 UL-COBF Scheduler 600, Figure 6 UL COBF transmissions by STAs S1-1, S1-2, S2-1, S2-2, S3-1, S3-2, S4-1, and S4-2 are shown.

[0116] Each AP can use its remaining three dimensions to null three interfering OBSS STAs in the UL (e.g., OBSS STAs received at the interfering AP). For example, a first AP, AP1, can simultaneously receive from STAs S1-1 and S1-2 in its BSS and null three interfering OBSS STAs in the UL (e.g., STAs S2-1, S3-1, and S4-1). In some aspects, COBF communication according to the teachings herein can achieve a fourfold gain in resource utilization compared to a scheme using conventional time division multiplexing (TDM) between four APs.

[0117] IV. Identify APs and STAs

[0118]

[0014] In some aspects, the present disclosure is directed to solving the following problem regarding identifying APs and STAs to be included in scheduling decisions.

[0119] Various criteria may be used to determine the DL and UL blanking OBSS APs per STA.In some aspects, the present disclosure relates to using per-STA estimated DL and UL RSSI or SINR to determine the DL and UL blanking OBSS APs required by the STA.

[0120] Various sequence formats may be used to measure DL and UL RSSI per AP.In some aspects, the present disclosure relates to measuring DL and UL RSSI per AP based on beacons, multi-BSS sounding sequences, new dedicated sequences, STAs' UL signals, or a combination thereof.

[0121] Various entities may make the above determinations. Furthermore, various OTA messages may be used for this purpose. In some aspects, the present disclosure relates to making the determination by a STA, its associated AP, or a third-party node (e.g., a cluster leader AP or a central controller). The required OTA message may be sent by the STA in the IEEE 802.11 High Efficiency (HE) control field of any frame, in the frame body of a dedicated frame, or in some other manner.

[0122] IV-A. Standards for determining DL blanking OBSS AP per STA

[0123] In some aspects, the criteria for determining the blanking OBSS AP may include determining the DL blanking OBSS AP per STA based on an estimated DL RSSI or SINR with the following options.

[0124] The first option uses RSSI per OBSS AP. If the RSSI caused by the mth OBSS AP at the STA is above a threshold (e.g., -92dBm), it should null the STA. Here, RSSI is measured from the mth OBSS AP without nulling.

[0125] The second option uses SINR with single AP interference. The mth OBSS AP should blank the STA if: 1) the STA's SINR (see Equation 1 below) drops by at least X dB (e.g., 3 dB); and / or 2) the SINR drops below Y dB (e.g., 20 dB).

[0126] SINR m =S / (I m +N) Formula 1

[0127] Here, S is the estimated RSSI from the serving AP without blanking, I m is the estimated RSSI from the mth OBSS AP with or without blanking, and N is the noise power.

[0128] The third option uses the worst SINR with all AP interference. For example, the worst case scenario could be that all potential scheduled APs are transmitting at full power in DL COBF transmission. The APs could be all APs in the same DL COBF cluster.

[0129] The worst-case SINR described above may be used to determine the blanked OBSS AP as in Equation 2.

[0130]

[0131] In formula 2, I m is the estimated RSSI from the mth OBSS AP with or without blanking.The parameters S and N may have the same meaning as in the second option.

[0132] The blanked OBSS AP set is the minimum set for blanking STAs so that: 1) the worst-case SINR A The drop is less than X dB (eg, 3 dB); or / and 2) the drop value is still higher than Y dB (eg, 20 dB).

[0133] The residual interference in the case of nulling can be estimated by subtracting a certain offset (eg, 30 dB) from the original interference. The residual interference can be signaled by the network or obtained in other ways.

[0134] IV-B. Standard for determining UL emptying OBSS AP per STA

[0135] The UL blanked OBSS AP may be determined per STA based on the estimated UL RSSI or SINR with the following options, or equivalently, the UL blanked OBSS STA may be determined per AP.

[0136] The first option uses RSSI per STA. If the RSSI caused by the STA at the AP is above a threshold (e.g., -92dBm), the AP should blank the mth OBSS STA. Here, RSSI is measured at the AP without blanking.

[0137] The second option uses the SINR with single STA interference. The AP should null the mth OBSS STA if: 1) the SINR of the STA served at the AP (see Equation 3 below) drops by at least X dB (e.g., 3 dB); and / or 2) the SINR drops below Y dB (e.g., 20 dB).

[0138] SINR m =S / (I m +N) Formula 3

[0139] Here, S can be the minimum or average RSSI of all served STAs at the AP without blanking, I m is the RSSI from the mth OBSS STA at the AP with or without blanking, and N is the noise power.

[0140] The third option uses the worst SINR with all STA interference. For example, the worst case scenario could be that all potential scheduled OBSS STAs are transmitting in UL COBF transmission. The above worst case SINR can be used to determine the blanked OBSS STAs at the AP as performed in Equation 4.

[0141]

[0142] In formula 4, I m is the estimated RSSI of the mth OBSS STA at the AP with or without blanking. Parameters S and N may have the same meanings as in the second option. The blanked OBSS STA set is the minimum set to be blanked such that: 1) the worst-case SINR A The decrease is less than X dB (eg, 3 dB); or / and 2) the decrease is still higher than Y dB (eg, 20 dB).

[0143] IV-C. Method for identifying DL and UL blanking OBSS APs per STA

[0144] In some aspects, the present disclosure relates to identifying DL and UL blanking APs per STA. In some aspects, this may involve obtaining input for identifying blanking APs, identifying blanking APs based on DL signaling, or identifying blanking APs based on UL signaling.

[0145] IV-C. Input for clearing AP ID.

[0146] As described above, the input for identifying blanking APs may include RSSI. The per-STA identification of DL blanking APs may be based on the DL RSSI of all APs at each STA. The per-STA identification of UL blanking APs may be based on at least the UL RSSI of the STA for all APs. Depending on the specific criteria used, the identification may also be based on the UL RSSI of the STAs served by each AP.

[0147] Therefore, the DL and UL COBF scheduler can determine the DL and UL RSSI between all APs and potential scheduled STAs. Alternatively, the scheduler can directly determine the identified DL and UL blanking APs on a per-STA basis. RSSI input or identification results can be provided by each AP.

[0148] Several options for the scheduler to obtain RSSI input or identification results on a per-STA basis will now be described. Initially, options based on DL signaling will be processed, followed by options based on UL signaling.

[0149] IV-C.2. DL signal-based identification

[0150] The identification based on DL signals may include the following three steps.

[0151] In the first step, the APs in the cluster send a DL measurement signal, and the STAs in the cluster measure the DL RSSI per AP based on the received signal.

[0152] In the second step, each STA reports its RSSI input and / or identification result to its associated AP. The result may include the STA's DL and UL blanking APID. The input may include the STA's DL and UL RSSI per AP.

[0153] The UL RSSI may be calculated based on the DL RSSI as follows: UL RSSI=STA transmit power−(AP transmit power−DL RSSI). The AP may indicate its transmit power in the AP's DL measurement signal.

[0154] In the third step, the scheduler collects the input and / or results of the STA using the latter options.

[0155] In the first option (Option 1), the AP exchanges the inputs and / or results of its InBSS STAs after receiving their STA reports. In this way, each AP can determine the inputs and / or results of all STAs when acting as a scheduler. This exchange can be triggered by the leader AP.

[0156] In the second option (Option 2), before each scheduling, each AP sends its candidate STA input and / or results to the scheduler. Each AP may send these inputs and / or results together with other information.

[0157] Three DL signal-based identification methods will now be described: a first method is a beacon-based method, a second method is a sounding-based method, and a third method is a dedicated sequence-based method.

[0158] IV-C.2.a. Method 1: Beacon-based method

[0159] Figure 7 This example illustrates signaling 700 in which an AP's beacon can be used as a DL measurement signal. Each AP can broadcast an offset between its transmit power for beacon and DL COBF transmission. The offset can be added to the measured beacon RSSI. The corrected DL RSSI can then be used for DL ​​blanking AP identification. The method employs the following steps.

[0160] In the first step, each AP sends a measurement request 702 to request the InBSS STA set to periodically measure the AP's beacon RSSI (e.g., once per second per AP). Figure 7 To reduce the complexity, only one AP (AP1) is shown. The selected InBSS STAs (e.g., STA1 and STA2) can be those with DL and / or UL traffic. The AP can indicate the STA's measurement period and target beacon transmission time (TBTT) offset per measuring AP in the request.

[0161] exist Figure 7 In the example of FIG, STA1 measures the beacon 704 of AP1 and measures the beacon 706 of AP2. In addition, STA2 measures the beacon 708 of AP1 and measures the beacon 710 of AP2.

[0162] In the second step, each STA reports the identification result and / or RSSI input to its associated AP to determine the above results (e.g., after receiving the trigger frame 712 from the AP). Figure 7 In the example, STA1 sends report 714 and STA2 sends report 716. The identification result may include the DL blanking AP ID and UL blanking AP ID of the STA. The RSSI input may include the DL RSSI of the STA per AP and the UL RSSI of the STA per AP.

[0163] In the third step, the DL and UL COBF schedulers collect inputs and / or results from STAs using the following two options.

[0164] In the first option (Option 1), the AP exchanges its InBSS STA input and / or results after receiving its corresponding STA report. For example, AP1 may send Figure 7 In this way, each AP is aware of the input and / or results of all STAs when acting as a scheduler. This exchange can be triggered by a trigger frame sent by the leader AP.

[0165] In the second option (Option 2), before each scheduling, each AP sends the input and / or results of its candidate STAs to the scheduler. For example, AP1 may send Figure 7 The information indicated in 718. Each AP may send these inputs and / or results along with other information.

[0166] IV-C.2.b. Method 2: Sounding-based method

[0167] In the sounding-based approach, a STA can measure the DL channel response per AP in a multi-BSS sounding procedure. Here, this procedure is reused to determine the blank AP ID of the STA.

[0168] In the first step, in a multi-BSS sounding procedure, a set of STAs across the BSSs is selected to measure the NDP for each AP and send the corresponding BFRP to the AP. The selected STAs can be those in the cluster with DL and / or UL traffic. The selected STAs can be announced in each AP's NDPA or in a single aggregated NDPA. See Section V for an example of a multi-BSS sounding sequence.

[0169] In the second step, the AP calculates the DL RSSI of each InBSS STA per AP and the UL RSSI per AP based on the STA's BFRP. The AP can know the AP and STA transmit power to determine the RSSI. The AP further determines the identification result of each InBSS STA.

[0170] The third step is the same as method 1.

[0171] IV-C.2.c. Method 3: Dedicated sequence-based method

[0172] Figure 8 An example of signaling 800 in which a dedicated sequence can be used as a DL measurement signal is illustrated. The DL measurement signal can be a new sequence, a simplified sounding sequence (e.g., where a STA only reports RSSI from multiple APs), or some other type of signal. The following sequence is an example for the case of two APs (AP1 and AP2).

[0173] In the first step, in each measurement cycle (e.g., repeated once per second), both APs send NDP announcements (NDPA) and NDPs sequentially. Figure 8In FIG, AP1 sends NDPA1 802 and NDP1 804, while AP2 sends NDPA2 806 and NDP2 808. Each AP specifies in the NDPA the InBSS STAs for which the RSSIs of the two NDPs are to be measured. The selected InBBSS STAs may be those with DL traffic and / or UL traffic.

[0174] In the second step, both APs send TF to collect the measured DL RSSI and UL RSSI from their STAs. Figure 8 In FIG. 8 , AP1 transmits TF1 810 and receives RSSI reports 812 from STAs in BSS1, while AP2 transmits TF2 814 and receives RSSI reports 816 from STAs in BSS2. Each AP further determines a per-STA DL blanking AP ID and a per-STA UL blanking AP ID.

[0175] The third step is the same as method 1. Figure 8 , AP1 sends result 818, and AP2 sends result 820.

[0176] IV-C.3. Identification based on UL signal

[0177] The identification based on the UL signal may include the following steps.

[0178] In the first step, STAs in the cluster send UL measurement signals. Each AP measures the UL RSSI between itself and each STA based on the received signals.

[0179] Each AP can also derive the DL RSSI between itself and each STA based on the UL RSSI. This derivation can use the following formula: DL RSSI = AP transmit power - (STA transmit power - UL RSSI). The STA can indicate its transmit power in the STA's UL measurement signal.

[0180] In the second step, the APs exchange their DL RSSI for each STA and the UL RSSI for each STA. In this way, each AP will know the DL RSSI per STA and the UL RSSI per STA of all APs. Based on the above RSSI inputs, each AP knows the identification results of all STAs when acting as a scheduler.

[0181] IV-C-3.a. Options for UL Signaling:

[0182] In the first option (Option 1) for UL signaling, each AP sends a Block ACK Request (BAR) to solicit a Block ACK (BA) from each selected InBSS STA. BARs / BAs can be sent in other frame types (e.g., RTS / CTS, TF / Response, etc.). TFs can indicate the response type (e.g., BSR, BQR, BA, CTS, NDP, etc.). The cluster leader AP can send TFs to poll each AP in the cluster to initiate a BAR / BA sequence. This process is repeated (e.g., every second).

[0183] Figure 9 An example of Option 1 signaling 900 for one BSS (BSS1) is illustrated. Initially, the cluster leader AP sends a TF 902. AP1 sends a BAR 904 to STA-1, which responds with a BA 906. AP1 sends a BAR 908 to STA-2, which responds with a BA 910. This process continues for all N STAs in the BSS. Ultimately, AP1 sends a BAR 912 to STA-N, which responds with a BA 914.

[0184] In the second option (Option 2) for UL signaling, each AP sends a TF to solicit responses from multiple InBSS STAs. The TF may indicate the response type (e.g., BSR, BQR, BA, CTS, NDP, etc.). The TF may allocate resources per STA (e.g., different subbands, time slots, spatial streams).

[0185] Figure 10 An example of signaling 1000 for Option 2 for one BSS (BSS1) is illustrated. Initially, the cluster leader AP sends a TF 1002. AP1 sends a TF 1004 to a first set of STAs (STA-1-STA-X). Each of these STAs sends a response, as represented by responses 1006 through 1008. This process continues for all N STAs in the BSS. Figure 10 In the example of FIG, AP1 sends a TF 1010 to a second set of STAs (STA-X+1-STA-N). Each of these STAs sends a response, as represented by responses 1012 to 1014.

[0186] IV-D. Options for Nulling the AP Identifier and Required Signaling

[0187] Various entities may be used to identify a blanking AP. The following describes options where the identifier is a STA, an AP, or a third-party node.

[0188] IV-D-1.STA is the identifier

[0189] In a first option, the STA determines the blanking APs on a per-STA basis. For example, the STA may identify its blanking APs based on the STA's measured DL RSSI for all APs and the measured UL RSSI for all APs.

[0190] In this case, the STA sends its DL and UL Blanking AP IDs to the STA's associated AP, which can then forward this information to potential DL and UL COBF schedulers (e.g., other APs). The STA can report the list in the HE Control field of any frame, in the frame body of a dedicated frame, or in some other manner. Reporting can have different report types, including, for example, polling by the AP, periodic reporting, or event-triggered reporting (e.g., reporting only when the list changes).

[0191] The AP may send the following information to assist the STA in making a decision: RSSI, SINR threshold, report type, or any combination thereof.

[0192] Two potential correction factors are as follows: If DL RSSI is estimated from beacons, an offset between the AP total transmit power for beacons and for DL ​​COBF transmissions can be used. An offset that estimates the residual interference (eg, how much to subtract) after nulling from the original interference can also be used.

[0193] IV-D-2.AP is an identifier

[0194] In the second option, the per-STA blanking AP is determined by the AP associated with the STA. Here, the STA sends back input for all APs (e.g., DL RSSI and UL RSSI). The AP determines the STA's DL blanking AP list and UL blanking AP list and can forward them to potential DL and UL COBF schedulers (e.g., other APs).

[0195] The following signaling may be used. The STA may send back the above estimates in the HE Control field of any frame, in the frame body of a dedicated frame, or in some other manner. The estimates may have different reporting types, including, for example, polled by the AP, periodic, or event-triggered (e.g., reporting only when any estimate changes).

[0196] IV-D-3. Third-party nodes are identifiers

[0197] In the third option, a third-party node (not the STA or its associated AP) determines the blanking AP on a per-STA basis. The third-party node can be the leader AP in a COBF cluster, a central controller connected to all APs via a backhaul, or another type of node. The STA sends the estimated RSSI input to its associated AP, which then forwards this information to the third-party node. The third-party node then determines the per-STA DL blanking AP and the per-STA UL blanking AP. If the third-party node is not the scheduler, the third-party node forwards this decision to the DL and UL COBF schedulers. This signaling can be similar to option 2.

[0198] V. Input Collection to Schedule Soundings for DL ​​Coordinated Beamforming Transmissions

[0199] To null out the OBSS STA in DL COBF transmission, the AP first determines the DL channel information for the STA. The channel can be estimated by performing a sounding procedure. The following are two examples of multi-BSS sounding sequences for DL ​​COBF.

[0200] Reference Figure 11 In the wireless communication system 1102 and signaling 1104 of the first DL COBF sounding example, each AP sends NDPA 1106, NDP 1108 and TF 1110 (e.g., aggregation trigger) to query the InBSS STAs and OBSS STAs that require blanking from the AP to measure NDP and send BFRP. Figure 11 In the example shown, STA S1 sends report 1112, STA S2 sends report 1114, STA S4 sends report 1116, STA S6 sends report 1118, and STA S8 sends report 1120. This sequence is performed for each BSS. Each AP sends an NDP-A, followed by an NDP in the baseline scenario, unless: 1) the AP is able to sound the OBSS STA (e.g., using UL OFDMA from the STA); 2) the STA will monitor the NDPA, NDP, and triggers sent from the OBSS AP; 3) the STA sends beamforming report information to the OBSS AP.

[0201] Figure 12 Wireless communication signaling 1202 illustrating a second DL COBF sounding example (e.g., which may be used by the wireless communication system 1102). Here, the master AP sends an NDPA, while each AP in the cluster sends an NDP and a TF to query the InBSS STAs and OBSS STAs that require blanking from the AP to measure their NDPs and send BFRPs. Figure 12, the master AP sends NDP-A 1202 (e.g., aggregated NDPA), followed by NDPs 1204 from AP-1, 1206 from AP-2, 1208 from AP-3, and 1210 from AP-4. Each AP sends a TF to poll the InBSSSTAs and OBSSSTAs that require blanking from the AP to send BFRPs. Figure 12 Here, AP1 sends TF 1212 (eg, aggregation trigger), and in response, STA S1 sends report 1214, STA S2 sends report 1216, STA S4 sends report 1218, STA S6 sends report 1220, and STA S8 sends report 1222.

[0202] The sounding scheduler can decide: 1) which InBSS STAs and OBSS STAs should measure the AP's NDP; 2) the STA's BFRP configuration; 3) each AP's NDP configuration (e.g., BW, maximum number of flows, etc.). The scheduler can be any node (e.g., an AP participating in DL COBF transmission or leading a DL COBF cluster, a central controller connected to all APs via backhaul, or some other node).

[0203] In some aspects, the present disclosure relates to techniques for the scheduler to signal the scheduling decision and the content of the decision (scheduling) to each participating AP. This enables each AP to announce the decision in its NDPA when necessary, configure its NDP accordingly, and trigger the corresponding STA to send a BFRP.

[0204] In some aspects, a node signals the scheduling decision in a frame it sounds at the start of a sounding session (e.g., in a "Multi-BSS Sounding Schedule" frame or in an aggregated NDPA). The scheduling decision may include the participating AP IDs and their NDP order, the IDs of the STAs that need to measure each AP's NDP, their BFRP configuration, and the AP's NDP configuration. The frame sender may be the scheduler. Otherwise, the scheduler communicates the scheduling decision to the frame sender.

[0205] In some aspects, the present disclosure relates to obtaining certain information to make the above decisions, and techniques for the scheduler to collect this information. In some cases, it may be beneficial to determine a minimum set of STAs to measure and report (for example, because the BFRP size may be large for a large number of STAs, BW, or flows).

[0206] In some aspects, the scheduler may use the following method to collect sounding candidate STA information per BSS.

[0207] The first method involves OTA explicit query. Before sounding the scheduler, the scheduler explicitly queries each AP.

[0208] The second method involves OTA autonomous advertising. Each AP autonomously advertises its input in the transmission frame.

[0209] A third approach involves a hybrid of approaches 1 and 2. For example, the scheduler may query only when it has not received an advertisement.

[0210] Another approach uses wired backhaul. Here, the scheduler can collect sounding scheduling information from all APs via the wired backhaul.

[0211] VA.DL COBF signaling for scheduling decisions

[0212] The following operations can be used to signal the sounding scheduling decision.

[0213] VA-1. Contents of the Exploration Decision

[0214] The scheduler may generate the following decision information for sounding scheduling. Other examples are also possible.

[0215] The decision may include the IDs of the APs that participate in the sounding. Also, the order in which the NDPs are sent may be specified.

[0216] For each of the above APs, the decision may include the ID of the STA that needs to measure the NDP of the AP, the BFRP configuration of each measuring STA, and the NDP configuration of the AP.

[0217] The IDs of STAs that need to measure the AP's NDP may include the AP's InBSS STAs and the AP's OBSS STAs that need blanking from the AP. The AP will later trigger them to report BFRP.

[0218] The BFRP configuration of each measuring STA may include, for example, a frequency tone grouping number and a codebook size.

[0219] The NDP configuration of the AP may include, for example, the NDP bandwidth and the maximum number of sounding flows.

[0220] The above decision can be signaled to each participating AP. In this way, each AP can announce the decision in its NDPA when necessary, configure its NDP accordingly, and trigger the corresponding STA to send BFRP.

[0221] VA-2. Scenario 1: Each AP sends its own NDPA in the sounding sequence (Sequence Example 1)

[0222] Reference Figure 13The signaling 1300 of the multi-BSS sounding schedule frame 1302 can send the scheduling decision at the beginning of the sounding sequence. Each AP then sends the NDPA, NDP, and TF to its STAs for BFRP. Each AP can know the order in which its NDP is transmitted and fill its NDPA with the relevant decision (for example, the ID of the STA that needs to measure the AP's NDP and the BFRP configuration for each measuring STA).

[0223] Figure 13 The per-BSS sequence for one BSS is illustrated. AP1 sends NDPA 1304, NDP 1306, and TF 1308 (e.g., aggregation trigger). In response, STA S1 sends report 1310, STA S2 sends report 1312, STA S4 sends report 1314, STA S6 sends report 1316, and STA S8 sends report 1318.

[0224] The sender of the scheduling frame can be the node that initiated the sounding sequence. If the scheduler is not the sender, the scheduler can pass the decision to the sender of the scheduling frame. If the two senders are the same, the scheduling frame can be merged into the NDPA of AP1.

[0225] VA-3. Scenario 2: One AP sends a single aggregated NDPA (Sequence Example 2)

[0226] Reference Figure 14 The scheduling decision can be sent in the aggregated NDPA at the beginning of the sounding sequence using signaling 1400. All participating APs and STAs will take action based on this decision. If the scheduler is not the sender, the scheduler can pass the decision to the sender of the aggregated NDPA. Alternatively, the scheduling decision can be sent in a separate frame before the aggregated NDPA.

[0227] exist Figure 14 In FIG, one AP sends NDP-A 1402 (e.g., aggregated NDPA with sounding scheduling), followed by NDPs from AP-1 1404, AP-2 1406, AP-3 1408, and AP-4 1410. Each AP sends a TF to request STAs to send BFRPs. Figure 14 Here, AP1 sends TF 1412 (eg, aggregation trigger), and in response, STA S1 sends report 1414, STA S2 sends report 1416, STA S4 sends report 1418, STA S6 sends report 1420, and STA S8 sends report 1422.

[0228] VA-4. Scenario 3: An AP sends a probe trigger and schedule frame to initiate UL probe signaling

[0229] Reference Figure 15Signaling 1500, available in Per BSS The start of UL sounding sends the scheduling decision in the sounding trigger and scheduling frame. Figure 15 In the example of FIG1 , AP1) will send individual NDP TFs to trigger the scheduled InBSS STAs to send NDPs, which will be measured by all APs. At the end of this process, each AP will have channel state information from all sounded STAs across the BSS. The sounding sequence can be simplified by sending a single aggregated sounding TF and scheduling frame for all BSSs at the beginning, and / or each scheduled AP can send only a single NDP TF at the beginning.

[0230] exist Figure 15 In the example shown in FIG1 , the cluster leader AP sends a sounding trigger and scheduling frame 1502 to BSS1. AP1 of BSS1 sends a TF 1504 to trigger STA-1 to send an NDP 1506. AP1 sends a TF 1508 to trigger STA-2 to send an NDP 1510. This operation is repeated for all N STAs in BSS1. Thus, ultimately, AP1 sends a TF 1512 to trigger STA-N to send an NDP 1514.

[0231] VB. Input collection for DL ​​COBF sounding scheduling

[0232] The following input collection operations may be used for sounding scheduling.The specific sounding scheduling inputs used may depend on the scheduling criteria, such as listed below.

[0233] The first criterion (Criterion 1) involves probing all STAs in the cluster. All STAs in any BSS of the cluster will measure the NDP of each AP and send a BFRP to the AP.

[0234] The second criterion (Criterion 2) involves STAs with DL data. The STAs with DL data (eg, STAs scheduled to receive DL data) will measure the NDP of each AP and send a BFRP to the AP.

[0235] The third criterion (Criterion 3) involves STAs with DL data that need blanking. The above STAs that also need blanking from the AP will measure the AP's NDP and send a BFRP to the AP.

[0236] VA-1. Input for sounding scheduling

[0237] Depending on the applicable criteria, the dispatcher may obtain the following information to make decisions.

[0238] In some aspects, the input may include the STA IDs per BSS that are potential DL COBF receivers. These STAs will support DL COBF reception and typically have DL data (e.g., scheduled). They may be identified by their associated AP or the STA itself. If criterion 1 above is used, there is no need to check the "Has DL Data" parameter.

[0239] If blanking from those APs is required (e.g., to determine which OBSS STAs should measure each AP's NDP), the input may also include the OBSS APID for each of the STAs. This input is not required if criteria 1 or 2 are used. Previously measured DL channel information from all APs to the STA can be used as input to the scheduler to determine the "Blank APID" rather than receiving an explicit "Blank AP ID."

[0240] For each of the above STAs, the input may also include capability information for DL ​​COBF sounding (e.g., to determine the STA's reporting configuration and the AP's NDP configuration). The capability information may include the frequency-frequency grouping size supported in the report (e.g., Ng = 16), the codebook size (quantization granularity) supported in the report, and the maximum number of sounding streams per supported NDP BW (to determine the AP's NDP configuration, e.g., BW and the maximum number of sounding streams).

[0241] The sounding scheduler may use the following method to collect the input information described previously.

[0242] VB-2. Method 1: OTA Explicit Query

[0243] Figure 16 The signaling 1600 of the first method is illustrated. Before sounding the scheduler (in this example, AP1) sends a query frame 1602 to solicit input from the participating APs (in this example, AP2, AP3, and AP4). The query frame 1602 also indicates the resources (e.g., different subbands, spatial streams, time slots) in response to each AP.

[0244] Each queried AP responds with an entry for its BSS (as listed previously). Figure 161604, AP2 responds with an input for BSS2, AP3 responds with an input for BSS3, and AP4 responds with an input for BSS4, 1608. The scheduler reports the scheduling decision to the NDPA sender (also AP1 in this example), which initiates the sounding sequence (e.g., as discussed above). For example, AP1 may send an aggregated NDPA 1610, after which AP1 sends DNP1 1612, AP2 sends DNP2 1614, AP3 sends DNP3 1616, and AP4 sends DNP4 1618. AP1 sends a TF 1620 and the STA measuring NDP 1 sends its BFRP 1622. This is performed for all NDPs (e.g., AP4 sends a TF 1624 and the STA measuring NDP 4 sends its BFRP 1626, and so on).

[0245] In by Figure 17 In an alternative implementation depicted by signaling 1700, the scheduler (AP1 in this example) may poll potential STAs in participating BSSs to obtain their per-STA information, rather than querying each AP for potential STAs that are DL COBF recipients. For example, AP1 may send a query 1702 for sounding schedule input in an UL OFDMA random access trigger frame. The potential STAs may then respond with their per-STA information 1704 (ID, OBSS APID for blanking, and sounding capabilities) via a random access procedure (e.g., similar to IEEE 802.11ax).

[0246] VB-3. Method 2: OTA Independent Advertising

[0247] Reference Figure 18 With signaling 1800, each AP may advertise the input of its BSS in the transmitted frame. For example, this information may be sent in the PHY preamble (such as in a new field in SIG-A, SIG-B, or the new SIG-C). As another example, this information may be sent in the MAC header (such as in a new HE Control field). In a DL MU PPDU, the new HE Control field may be multicast to other APs in the same cluster on a dedicated resource element (with RA as the cluster ID). As yet another example, the information may be sent in a new information element (IE), in the body of a management / action frame, such as a beacon.

[0248] Dispatcher ( Figure 18 The AP1 in the example of NDPA decides the schedule based on the latest advertisement of each participant AP. Subsequently, the scheduler reports the schedule decision to the NDPA sender (also AP1 in this example).

[0249] The AP can signal in the PHY preamble that the frame carries candidate STA information. In this way, the OBSS AP will not discard the frame for reuse.

[0250] exist Figure 18 , AP3 sends input for BSS3 1802, AP1 sends input for BSS1 1804, AP2 sends input for BSS2 1806, and AP4 sends input for BSS4 1808. Subsequently, AP1 may send aggregated NDPA 1810, after which AP1 sends DNP1 1812, AP2 sends DNP2 1814, AP3 sends DNP3 1816, and AP4 sends DNP4 1818.

[0251] In by Figure 19 In an alternative implementation depicted by signaling 1900, STAs that are potential DL COBF recipients can advertise their per-STA information in transmitted frames 1902-1904. The information placement within the frames can be similar to the AP advertising scenario described above. The scheduler (AP1 in this example) makes scheduling decisions based on the latest advertisement from the advertising STA and reports its scheduling decision to the sender of the NDPA 1906 (also AP1 in this example).

[0252] VB-4. Method 3: A combination of methods 1 and 2

[0253] The scheduler may query a participant AP only when the scheduler has not recently received an advertisement from the participant AP (e.g., within the last 50ms). This potentially saves query overhead.

[0254] VB-5. Method 4: Based on wired backhaul

[0255] The scheduler can collect the sounding scheduling input from all participating APs via the wired backhaul. These APs can be located in the same DLCOBF cluster.

[0256] VB-6. Dedicated Resources for Scheduling

[0257] In OTA methods 1-3, scheduling-related information can be sent on dedicated resources different from DL COBF transmission resources (e.g., in different time slots, frequency channels, and / or spatial streams). Scheduling-related information may include explicit query and response frames for potential sounded STA information, autonomous advertisement frames for potential sounded STA information, and frames carrying DL COBF sounding scheduling decisions. For example, when the scheduler is not the NDPA sender, the scheduler may send the decision to the NDPA sender via these frames.

[0258] As a specific example, the advertisement frames may be sent in periodic time windows on a common management channel (eg, a channel in the 900 MHz band or the 2.4 GHz band).

[0259] VB-7. Limitation on the number of STA reports

[0260] To save overhead, there may be a limit on the reported or advertised number of candidate STAs to be sounded in methods 1 through 4. In method 1, the limit may be specified by the querying AP in the query frame. In method 2, the limit may be specified by the cluster leader AP. In method 4, the limit may be specified by a central controller.

[0261] This limit may include the total number of reported / advertised candidate STAs per AP. This limit may also include the total maximum number of supported streams for the reported / advertised candidate STAs per AP. The above metric may apply to all candidate STAs, all candidate STAs that need to be blanked, or all candidate STAs that do not need to be blanked.

[0262] VI.DL Coordinated Beamforming Transmission Scheduling Signaling and Input Collection

[0263] In some scenarios, the scheduling decision may be made by a node (e.g., an AP participating in DL COBF transmission or leading a DL COBF cluster, or a central controller connected to all APs via backhaul). The scheduler ensures that each participating AP has sufficient dimensions to serve the selected InBSS STAs and blanks the selected OBSS STAs that need to be blanked.

[0264] In some aspects, the present disclosure relates to techniques for the scheduler to signal the decision and the content of the decision to each participating AP. In this way, each AP knows which InBSS STAs to serve and which OBSS STAs to blank in a DL COBF transmission.

[0265] The node may signal the scheduling decision in a frame prior to the DL COBF transmission (e.g., the trigger frame that triggers the DL COBF transmission). The scheduling decision may include each scheduled STAID, the corresponding number of streams, the OBSS APID (if blanked, if necessary), and the resources used for UL ACK. The frame sending node may be the scheduler. Otherwise, the scheduler communicates the scheduling decision to the frame sending node.

[0266] In some aspects, the present disclosure relates to techniques for determining which inputs to use for the above-mentioned scheduling and how the scheduler can collect them. Here, the scheduler determines which STAs with DL COBF capabilities have DL data (e.g., scheduled) per BSS and their urgency at that moment.

[0267] The scheduler may use the following four methods to collect input about candidate STAs on a per BSS basis.

[0268] The first method (method 1) involves OTA explicit querying: the scheduler explicitly queries each AP for the input of the AP's BSS before the COBF transmission.

[0269] The second method (Method 2) involves OTA autonomous advertising. The scheduler is aware of each AP's input from previous advertising.

[0270] The third method (method 3) is a hybrid of methods 1 and 2. The scheduler only queries when it is not receiving an advertisement.

[0271] The fourth method (Method 4) uses a wired backhaul. The scheduler collects input from all APs via the wired backhaul.

[0272] VI-A. DL COBF Scheduling Decision Signaling

[0273] The following operations may be used to signal DL COBF scheduling decisions.

[0274] VI-A-1. Frame used to send DL COBF scheduling decision

[0275] Reference Figure 20 In signaling 2000, the cluster leader AP or any AP can send a "multi-AP trigger" to initiate DL COBF transmission. Figure 20 In the example shown in FIG, the AP sends a “Multi-AP Trigger” 2002 that triggers DL COBF transmissions 2004 from AP1, 2006 from AP2, 2008 from AP3, and 2010 from AP4. The STAs in the cluster respond to these DL COBF transmissions with UL ACK 2012.

[0276] If the scheduler is also the node that sends the trigger, the scheduler can send the scheduling decision in the trigger frame. Otherwise, the scheduler can pass the scheduling decision to the triggering node.

[0277] Alternatively, the scheduling decision may be sent in a separate frame before or after the trigger frame. In this case, the scheduler may pass the scheduling decision to the frame sender.

[0278] VI-A-2. Scheduling Signaling for DL ​​COBF Transmission Sequences

[0279] Reference Figure 21 With signaling 2100, the initiator node may maintain a long TXOP for a sequence of DL COBF transmissions. The per-transmission scheduling decision may be signaled in the following options. In the first option, the decision for all transmissions is signaled in the primary frame (e.g., the first multi-AP TF). In the second option, the per-transmission decision is signaled in the multi-AP TF prior to the DL COBF transmission. Furthermore, the first TF may indicate the STAIDs that may be scheduled in subsequent transmissions.

[0280] Figure 21 An example of the first option is illustrated in which a primary frame 2102 (e.g., a multi-AP TF with scheduling for all transmissions) triggers DL COBF transmissions from AP1 2104, DL COBF transmissions from AP2 2106, DL COBF transmissions from AP3 2108, and DL COBF transmissions from AP4 2110. The scheduled STAs in the cluster respond to these DL COBF transmissions with UL ACKs 2112.

[0281] Figure 21 Also illustrated is an example of a second option in which a trigger frame 2114 (e.g., a multi-AP TF with a schedule for the next transmission) triggers a DL COBF transmission from AP1 2116, a DL COBF transmission from AP2 2118, a DL COBF transmission from AP3 2120, and a DL COBF transmission from AP4 2122. The scheduled STAs in the cluster respond to these DL COBF transmissions with a UL ACK 2124.

[0282] Reference Figure 22 In the signaling 2200 with multiple DL COBF transmissions per TXOP, the sequence can be simplified by omitting the following multiple AP TFs. Alternatively or additionally, the STA UL ACK can be replaced by a delayed ACK (eg, the delayed ACK is later solicited by the AP).

[0283] exist Figure 22 In FIG. 2 , a primary frame 2202 (e.g., a multi-AP TF with scheduling for all transmissions) triggers DL COBF transmissions 2204 from AP1, 2206 from AP2, 2208 from AP3, and 2210 from AP4. The scheduled STAs in the cluster respond to these DL COBF transmissions with UL ACKs 2212. The primary frame 2202 also triggers DL COBF transmissions 2214 from AP1, 2216 from AP2, 2218 from AP3, 2220 from AP4, and so on.

[0284] VI-A-3. Contents of DL COBF Scheduling Decision

[0285] The scheduling decision may include scheduling information for data transmission and scheduling information for UL ACK transmission.

[0286] Scheduling information for data transmission may include the scheduled STA ID per BSS. Furthermore, for each of the aforementioned STAs, this information may include the starting stream index, number of streams, modulation and coding scheme (MCS), and OBSS APID (if blanking from these is required). Alternatively, this information may include, for example, blanking of OBSS APs not required within a cluster. This information may also include the total duration and bandwidth of the DL COBF transmission.

[0287] The scheduling information for UL ACK transmission may include a STAID and ACK resource information (eg, starting stream index, number of streams, time slot, subband, and MCS) for each scheduled STA.

[0288] VI-A-4. AP / STA Actions After Receiving the Decision

[0289] After receiving the scheduling decision, each AP participating in the DL COBF transmission may take the following actions. The AP may perform DL COBF transmission for scheduled InBSS STAs while forming nulls for OBSS STAs that require nulling from the AP. The AP may also convey UL ACK scheduling information to each scheduled InBSS STA via the DL COBF transmission. For example, this information may be sent in the HE Control field in a data frame or in a separate trigger frame (e.g., a short NDP frame) addressed to each scheduled STA.

[0290] After receiving the DL COBF transmission, each STA may send a UL ACK based on the indicated UL ACK scheduling information.

[0291] VI-B. Input Collection for DL ​​COBF Scheduling

[0292] The following input collection operations may be used for DL ​​COBF scheduling: As described above, the scheduler collects candidate STA information per BSS to cross-BSS scheduled STAs for each DL COBF transmission.

[0293] VI-B-1. Method 1: OTA Explicit Query

[0294] Reference Figure 23 Signaling 2300, after obtaining the transmission opportunity (TXOP), the scheduler ( Figure 23 In the example of FIG, AP1) sends a query frame 2302 to request candidate STA information from the set of APs. The query frame also indicates the resources (e.g., different subbands, spatial streams, time slots, etc.) to which each AP responds.

[0295] Each AP responds with the candidate STA information of its BSS. Figure 23, AP2 responds with candidate STA information 2304 of BSS2, AP3 responds with candidate STA information 2306 of BSS3, and AP4 responds with candidate STA information 2308 of BSS4.

[0296] The scheduler sends a TF with scheduling decisions based on the collected inputs 2310. AP1 sends a DL COBF transmission 2312, AP2 sends a DL COBF transmission 2314, AP3 sends a DL COBF transmission 2316, and AP4 sends a DL COBF transmission 2318. The scheduled STAs send their UL ACKs 2320.

[0297] VI-B-2. Method 2: OTA Self-Advertising

[0298] Reference Figure 24 Each AP advertises candidate STA information in its transmitted frames using signaling 2400 (the AP may signal in the PHY preamble that the frame carries candidate STA information so that the OBSS AP does not discard the frame for reuse). For example, this information may be advertised in the PHY preamble (such as in a new field in SIG-A, SIG-B, or the new SIG-C). This information may be advertised in the MAC header (such as in a new HE Control field, e.g., in the AP's TF). In a DL MU PPDU, the new HE Control field may be multicast to other APs in the same cluster on a dedicated resource element (with RA as the cluster ID). This information may also be sent in a new IE or in the body of a management / action frame, such as a beacon.

[0299] exist Figure 24 In the example, AP3 sends candidate STA information 2402 of BSS3, AP1 sends candidate STA information 2404 of BSS1, AP2 sends candidate STA information 2406 of BSS2, and AP4 sends candidate STA information 2408 of BSS4.

[0300] After obtaining TXOP, the scheduler ( Figure 24 AP1 in the example of FIG4 determines a schedule based on the latest advertisement per AP and sends out a TF 2410. AP1 sends a DL COBF transmission 2412, AP2 sends a DL COBF transmission 2414, AP3 sends a DL COBF transmission 2416, and AP4 sends a DL COBF transmission 2418.

[0301] VI-B-3. Method 3: OTA-run advertising at predefined times

[0302] Method 3 is similar to method 2, however, there is a defined time period during which the AP may publish this information, e.g. Figure 25As shown in . The scheduler AP will listen during the "advertisement" period to collect information from other APs. The scheduler can advertise this schedule until the end of each advertising period. In some systems, this schedule will remain true until the next advertising period.

[0303] exist Figure 25 In the figure, during a first time period, AP1 transmits candidate STA information 2502 for BSS1, AP2 transmits candidate STA information 2504 for BSS2, AP3 transmits candidate STA information 2506 for BSS3, and AP4 transmits candidate STA information 2508 for BSS4. AP1 transmits TF 2510, after which AP1 transmits DL COBF transmission 2512, AP2 transmits DL COBF transmission 2514, AP3 transmits DL COBF transmission 2516, and AP4 transmits DL COBF transmission 2518. Subsequently, during a second time period, AP1 transmits candidate STA information 2520 for BSS1, AP2 transmits candidate STA information 2522 for BSS2, AP3 transmits candidate STA information 2524 for BSS3, and AP4 transmits candidate STA information 2526 for BSS4.

[0304] VI-B-4. Method 3: A combination of methods 1 and 2

[0305] The scheduler queries the AP only when the scheduler has not received an advertisement from the AP recently (e.g., within the last 50ms). This can save query overhead.

[0306] VI-B-5. Method 4: Wired Backhaul

[0307] The scheduler collects candidate STA information from all APs via the wired backhaul. These APs may be located in the same DL COBF cluster.

[0308] VI-B-6. Dedicated resources for scheduling related information

[0309] In OTA methods 1-3, scheduling-related information may be sent on dedicated resources different from DL COBF transmission resources (e.g., different time slots, frequency channels, and / or spatial streams). Scheduling-related information may include explicit query and response frames for candidate user information, autonomous advertisement frames for candidate user information, frames carrying DL COBF transmission scheduling decisions, and frames triggering multi-AP DL COBF transmissions. This information may be sent on a different channel from DL COBF transmissions.

[0310] As a specific example, advertisement frames may be sent in periodic time windows on a common management channel (eg, a channel in the 900 MHz or 2.4 GHz band).

[0311] VI-B-7. Contents of Candidate STA Information

[0312] The candidate STA information sent by the AP may include, for example, STA information for data transmission and STA information for UL ACK transmission.

[0313] STA information for data transmission may include candidate STA IDs in the AP's BSS. Typically, these STAs will support DL COBF Rx and have DL data at this time. For each candidate STA, this information may also include: DL COBF reception capabilities (e.g., maximum stream # per supported BW, whether fractional BW is supported); required DL data resources (e.g., transmission duration for reference BW and stream #, or amount of buffered data + MCS); OBSS APID (if blanking from them is required) (the APs considered may be those in the same cluster); scheduling priority metrics (e.g., highest access category for buffered DL data, maximum latency, latency requirement, proportional fairness metric (ratio of instantaneous rate to average rate)); and inputs for checking DL RSSI differences (as specified below).

[0314] For each candidate STA, the STA information for UL ACK transmission may include UL ACK transmission capability, required UL ACK resources (similar to that for DL ​​COBF data transmission above), and MCS.

[0315] VI-B-8. Input for DL ​​RSSI Difference Check

[0316] The following check ensures that participating APs across BSSs can mutually meet the maximum tolerable RSSI difference requirement at their scheduled STAs. For each participating STA, the RSSI of each OBSS AP at the STA (without nulls) must be less than or equal to the maximum tolerable RSSI at the STA. Alternatively, the condition "of each OBSS AP" can be replaced by "of the sum of the OBSS APs."

[0317] The above check may use the following inputs per candidate STA.

[0318] The first input (Input 1) is the maximum tolerable RSSI at the STA. This is equal to the STA's own AP's RSSI for the STA plus the maximum tolerable RSSI difference. The STA's AP's RSSI for the STA is equal to the AP's allocated transmit power for the STA minus its PL.

[0319] The second input (Input 2) is the RSSI of each AP at the STA. This RSSI is equal to the total transmit power of the AP minus the corresponding PL. Both inputs can be replaced by other similar forms (e.g., variables used to calculate the input).

[0320] VI-B-9. Additional Input

[0321] The scheduler can ensure that DL COBF scheduling meets the following feasibility requirements: For each AP that joins DL COBF reception, the total dimension used for blanking + the dimension of its served InBSS STAs <= its total available dimension for DL ​​COBF.

[0322] To check the above requirements, the scheduler can determine the total available dimension for DL ​​COBF per AP. This information can be obtained via OTA messages. For example, each AP can signal its total dimension for DL ​​COBF in the transmitted frame, for example, in a new "DL COBF Capability" information element (IE) in the beacon, or sent together with the candidate STA information.

[0323] VI-B-10. Limitation on the number of STA reports

[0324] To save overhead, there may be a limit on the number of candidate STAs reported or advertised in methods 1-4 just described. In method 1, this limit may be specified by the querying AP in the query frame. In method 2, this limit may be specified by the cluster leader AP. In method 4, this limit may be specified by the central controller.

[0325] This limit can be in the form of: total reported / advertised candidate STA number per AP; maximum total number of supported streams for reported / advertised number of candidate STAs per AP. The above metrics can be for total candidate STAs, total candidate STAs that need to be blanked, or total candidate STAs that do not need to be blanked.

[0326] VI-B-11. Cascade Scheduling

[0327] An example of cascade scheduling is in Figure 26 As shown in the signaling 2600 of . As mentioned above, the previous method describes a scenario where one scheduler makes a scheduling decision. In other implementations, scheduling decisions can be made by all APs in a distributed manner. After obtaining the TXOP, the initiator node ( Figure 26 In the example of FIG, AP1) sends a frame 2602 with scheduling decisions for its own InBSS STAs. This frame indicates the order in which the OBSS APs respond with decisions for their InBSS STAs. The frame also indicates the orthogonal partitioning of the remaining resources among the OBSS APs for both DL COBF transmission and UL ACK (e.g., AP2-AP4 use the remaining dimensions 3-4, 5-6, and 7-8 for their InBSS STAs, respectively).

[0328] Each AP responds with scheduling decisions for its own InBSS STAs within the assigned resource range and in the assigned order. Figure 26, AP2 sends its scheduling decision 2604, followed by AP3 sending its scheduling decision 2606, and then AP4 sending its scheduling decision 2608. Thus, each AP is aware of the decisions of the other APs.

[0329] The response of the last AP (AP4 in this example) also triggers a multi-AP DL COBF transmission: AP1 sends a DL COBF transmission 2610, AP2 sends a DL COBF transmission 2612, AP3 sends a DL COBF transmission 2614, and AP4 sends a DL COBF transmission 2616. The scheduled STAs send their UL ACKs 2618.

[0330] VII. UL Coordinated Beamforming Receive Scheduling Signaling and Input Collection

[0331] For the UL, in some scenarios, the scheduling decision may be made by one node (e.g., an AP participating in UL COBF reception or leading a UL COBF cluster, or a central controller connected to all APs via backhaul). The scheduling node ensures that each participating AP has sufficient dimensions to serve the selected InBSS STAs and blanks the selected OBSS STAs that need to be blanked in the UL.

[0332] In some aspects, the present disclosure relates to techniques for a scheduling node to signal a decision and the content of the decision to each participating AP. In this way, each AP knows which InBSS STAs to serve and which OBSS STAs to blank in UL COBF reception.

[0333] A node may signal a scheduling decision in a frame prior to UL COBF reception (e.g., a scheduling frame prior to AP TF and UL COBF transmission). The scheduling decision may include each scheduled STA ID, the corresponding number of streams, the OBSS APID (if blanked), and the resources used for DL ​​ACK per AP. The decision may also include the resource allocation per AP TF to trigger transmissions for its STAs. The frame sending node may be the scheduling node. Otherwise, the scheduling node may communicate the scheduling decision to the frame sending node.

[0334] In some aspects, the present disclosure relates to techniques for determining inputs to be used for the above-mentioned scheduling and how the scheduling node collects them. Here, the scheduling node can determine which STAs with UL COBF capability have UL data and their urgency at that moment on a per-BSS basis.

[0335] The scheduling node may use the following four methods to collect input about candidate STAs per BSS.

[0336] The first method (method 1) involves OTA explicit querying: the scheduling node directly and explicitly queries each AP or individual STA.

[0337] The second method (Method 2) involves OTA autonomous advertising. The scheduling node is aware of each AP's input from previous advertisements.

[0338] The third method (method 3) is a hybrid of methods 1 and 2. For example, the scheduling node may query only when it is not receiving an advertisement.

[0339] The fourth method (Method 4) uses a wired backhaul. The scheduling node collects input from all APs via the wired backhaul.

[0340] VII-A. Signaling of UL COBF Scheduling Decisions

[0341] The following operations may be used to signal the UL COBF scheduling decision.

[0342] VII-A-1. Frame used to send UL COBF scheduling decision

[0343] Reference Figure 27 To align UL transmissions from multiple BSS STAs, each AP can send individual TFs to trigger UL transmissions from its STAs at target times. For example, AP1 through AP4 can each send a TF (represented by TFs 2702 through 2704). The STAs will then respond to TFs 2702 through 2704 by sending their UL transmissions (represented by UL transmission 2706 from STA1-1, UL transmission 2708 from STA1-2, and UL transmission 2710 from STA4-2).

[0344] The controller can provide the TF transmission reference time. The controller can be the AP or a separate entity.

[0345] To avoid interference, individual AP TFs can use orthogonal resources. For example, TFs can be transmitted via different time slots, different frequency bands, or different spatial streams.

[0346] Figure 28Signaling 2800 illustrates an alternative example of using shared resources rather than orthogonal resources for TFs. In this scenario, individual AP TFs can use the same resources with the same PHY and MAC format to send a multi-BSS UL trigger frame 2802. The STAs will then send their UL transmissions in response to TF 2802 (represented by UL transmission 2804 from STA1-1, UL transmission 2806 from STA1-2, and UL transmission 2808 from STA4-2). Here, TFs 2802 carry the same content and are therefore essentially identical signals at the STAs. This technique may require fewer resources than TFs in different time slots and may be more easily received by STAs than TFs in different subbands or spatial streams.

[0347] A node can send the UL COBF scheduling decision in a scheduling frame before or after the individual AP TF. This node can be the leader AP or any AP in the cluster that won access (e.g., AP1). If the scheduler is not the sender, the scheduler passes the decision to the sender of the scheduling frame. The scheduling frame can also serve as a multi-AP TF for the individual AP TF.

[0348] After receiving the scheduling frame, each AP copies at least the decisions related to its InBSS STAs to its individual TFs. If TFs are sent on the same resources, the AP ensures that the TFs have the same content, for example, by copying the decisions for all STAs to the TFs. The scheduling frame sender may or may not send individual TFs.

[0349] Figure 29 Signaling 2900 illustrates an example in which AP1 sends a TF with a scheduling decision 2902, after which AP1 through AP4 send their own TFs (represented by TFs 2904 through 2906). The STAs send their UL transmissions in response to the TFs (represented by UL transmission 2908 from STA1-1, UL transmission 2910 from STA1-2, and UL transmission 2912 from STA4-2). Subsequently, the APs acknowledge the UL transmissions (represented by ACK 2914 from AP1 through ACK 2916 from AP4).

[0350] Reference Figure 30 Signaling 3000, if all scheduled STAs are within range of the scheduling frame sender, individual AP TFs can be avoided. In this case, the scheduling frame can directly trigger all scheduled STAs. An indicator in the scheduling frame can be set to notify the AP to skip TFs. The scheduling frame sender can identify all STAs within range based on the scheduling input for all STAs (discussed below) (e.g., a blank AP ID for each STA, DL / UL RSSI, or PL for each AP in the cluster).

[0351] exist Figure 30 In the example, AP1 sends a TF with a scheduling decision 3002, and the STAs then send their UL transmissions in response to the TF (represented by UL transmission 3004 from STA1-1, UL transmission 3006 from STA1-2, and UL transmission 3008 from STA4-2). Subsequently, the APs acknowledge the UL transmissions (represented by ACK 3010 from AP1 and ACK 3012 from AP4).

[0352] VII-A-2. Scheduling Signaling for UL COBF Transmission Sequences

[0353] In some scenarios, the initiator node may maintain a long TXOP for a sequence of UL COBF transmissions. The following options may be used to signal the scheduling decision for each transmission. In the first option, the decision for all transmissions is signaled in the primary frame (e.g., the first multi-AP TF). In the second option, the decision for each transmission is signaled in the multi-AP TF before each UL COBF transmission. Furthermore, the first multi-AP TF may indicate the STA IDs that are potentially scheduled in subsequent transmissions.

[0354] Figure 31 3100 illustrates an example of a first option in which a primary frame 3102 (e.g., multiple APTFs with scheduling for all transmissions) triggers TFs 3104 from AP1, 3106 from AP2, 3108 from AP3, and 3110 from AP4. The scheduled STAs in the cluster respond to these TFs with UL COBF transmissions 3112. The APs then acknowledge the UL transmissions (represented by ACKs 3114 from AP1, 3116 from AP2, 3118 from AP3, and 3120 from AP4).

[0355] Figure 31 Also illustrated is an example of a second option in which a trigger frame 3122 (e.g., a multi-AP TF with a schedule for the next transmission) triggers a TF 3124 from AP1, a TF 3126 from AP2, a TF 3128 from AP3, and a TF 3130 from AP4. The scheduled STAs in the cluster respond to these TFs with a UL COBF transmission 3132. The APs then acknowledge the UL transmissions (represented by ACK 3134 from AP1, ACK 3136 from AP2, ACK 3138 from AP3, and ACK 3140 from AP4).

[0356] In scenarios with multiple UL COBF transmissions per TXOP, the sequence can be simplified by combining each AP's ACK with the TF and ignoring the multiple AP TFs in between. Alternatively or additionally, the AP's ACK can be replaced by a delayed ACK (which is sent to the AP later).

[0357] Figure 32 3200 illustrates an example of the second option where ACK is combined with TF. A primary frame 3202 (e.g., multi-AP TF with scheduling for all transmissions) triggers TF 3204 from AP1, TF 3206 from AP2, TF 3208 from AP3, and TF 3210 from AP4. The scheduled STAs in the cluster respond to these TFs with UL COBF transmissions 3212. The APs then acknowledge the UL transmissions, with each acknowledgment including a TF (represented by ACK+TF 3214 from AP1, ACK+TF 3216 from AP2, ACK+TF 3218 from AP3, and ACK+TF 3220 from AP4). The scheduled STAs in the cluster respond to these ACK+TFs with UL COBF transmissions 3222. If there are no more UL transmissions, the APs only acknowledge the last UL transmission (represented by ACK 3224 from AP1, ACK 3226 from AP2, ACK 3228 from AP3, and ACK 3230 from AP4).

[0358] VII-A-3. Contents of UL COBF Scheduling Decision

[0359] The scheduling decision may include, for example, scheduling information for individual AP TFs, scheduling information for UL data transmission, and scheduling information for DL ​​ACK transmission.

[0360] For each participating AP, the scheduling information for the individual AP TF may include the AP ID and the allocated resources for its TF (e.g., starting stream index, stream #, time slot, subband, MCS, etc.) For the entire individual AP TF transmission, the scheduling information may also include the total duration and bandwidth.

[0361] For each scheduled STA, the scheduling information for UL data transmission may include the STA ID, the allocated resources for its UL COBF transmission (as listed above), the OBSS APID (if UL blanking is required for those APs), the STA's target RSSI at the associated AP or the STA's maximum target RSSI, the transmit power or the maximum transmit power (to potentially control over-silence issues due to multi-BSS transmissions). For the entire UL COBF transmission, the scheduling information may also include the total duration, bandwidth, number of long training fields (LTFs), guard intervals (GIs), and LTF duration.

[0362] For each participating AP, the scheduling information for DL ​​ACK transmission may include the allocated resources for DL ​​ACK for all of its STAs (e.g., starting stream index, stream #, time slot, subband, MCS), or the allocated resources for DL ​​ACK for each of its STAs (e.g., by specifying DL ACK resources per STA).

[0363] VII-B. Input Collection for UL COBF Scheduling

[0364] For example, the following candidate STA information may be sent to the scheduler by the STA's associated AP or by the STA itself as scheduling input: STA information for UL data transmission and STA information for DL ​​ACK transmission.

[0365] STA information for UL data transmission may include candidate STAID(s). These STAs should support UL COBF transmission and typically have UL data at this time. For each candidate STA, the STA information may include: STA_ID, UL COBF transmission capabilities (e.g., maximum stream # per supported BW, whether partial BW is supported); required UL data resources (e.g., transmission duration, amount of buffered data, and MCS for reference BW and stream #); OBSS APID (if UL blanking is required for those APs); scheduling priority metrics (e.g., highest access category of buffered UL data, maximum wait time, wait time requirement, proportional fairness metric (ratio of instant rate to average rate)); and input to check UL RSSI difference (as specified below).

[0366] The STA information for DL ​​ACK transmission may include the required DL ACK resources (similar to that for data transmission above) and MCS of the candidate STAs.

[0367] The following check ensures that scheduled STAs across the BSS can meet each other's maximum tolerable RSSI difference requirements. For each participating AP, the RSSI caused by each STA to the AP is less than or equal to the maximum tolerable RSSI per STA of that AP. In an alternative check, the term "per STA" can be replaced with "the sum of the STAs" (excluding "per STA"). For each participating AP, an alternative check can be that the RSSI caused by the sum of the STAs to the AP is less than or equal to the maximum tolerable RSSI of the AP.

[0368] The above check may use one or more of the following inputs per candidate STA. The first input is the STA's maximum tolerable RSSI at its own AP. This is equal to the target RSSI for the STA's MCS plus the maximum tolerable RSSI difference. The second input is the RSSI that the STA contributes to each AP. This can be calculated as the STA's target RSSI at its own AP plus the STA's PL for its own AP minus the STA's PL for each AP considered. Both inputs can be replaced by other similar forms (e.g., the variables used to calculate them).

[0369] For each UL COBF transmission, the scheduler collects candidate STA information per BSS to the cross-BSS scheduled STAs. The following are several examples of input.

[0370] VII-B-1. Method 1: OTA Explicit Query

[0371] Reference Figure 33 Signaling 3300, after obtaining TXOP, the scheduler ( Figure 33 In the example of FIG, AP1) sends a query frame 3302 to request candidate STA information from the set of APs. The query frame also indicates the resources (e.g., different subbands, spatial streams, time slots, etc.) to which each AP responds.

[0372] Each AP responds with the candidate STA information of its BSS. Figure 33 In the example, AP2 responds with the candidate STA information 3304 of BSS2, AP3 responds with the candidate STA information 3306 of BSS3, and AP4 responds with the candidate STA information 3308 of BSS4.

[0373] The scheduler sends a multi-AP TF with scheduling decisions 3310. AP1 sends TF 3312, AP2 sends TF 3314, AP3 sends TF 3316, and AP4 sends TF 3318. The scheduled STAs send their UL transmissions 3320. The APs then acknowledge the UL transmissions (represented by ACK 3322 from AP1, ACK 3324 from AP2, ACK 3326 from AP3, and ACK 3328 from AP4).

[0374] In by Figure 34 In an alternative approach, as depicted by signaling 3400, the scheduler (in this example, AP1) can poll potential STAs within its range to obtain their per-STA information, rather than querying each AP. For example, AP1 can send a query 3402 in an UL OFDMA random access TF. Potential STAs respond with their per-STA information 3404 (as discussed above) via the random access procedure.

[0375] VII-B-2. Method 2: OTA Self-Advertising

[0376] Each AP may advertise candidate STA information in its transmitted frames (e.g., the AP may signal in the PHY preamble that the frame carries candidate STA information so that the OBSS AP does not discard the frame for reuse). For example, this information may be advertised in the PHY preamble (e.g., in a new field in SIG-A, SIG-B, or the new SIG-C). This information may be advertised in the MAC header (e.g., in a new HE Control field). In a DL MU PPDU, the new HE Control field may be multicast to other APs in the same cluster on a dedicated resource element (with RA as the cluster ID). This information may be sent in a new IE or in the body of a management / action frame, such as a beacon.

[0377] exist Figure 35 In the signaling 3500, AP3 sends candidate STA information 3502 of BSS3, AP1 sends candidate STA information 3504 of BSS1, AP2 sends candidate STA information 3506 of BSS2, and AP4 sends candidate STA information 3508 of BSS4.

[0378] After obtaining TXOP, the scheduler ( Figure 35 AP1 in the example of FIG5 ) determines a schedule based on the latest advertisement per AP and sends multi-AP TF 3510. AP1 sends TF 3512, AP2 sends TF 3514, AP3 sends TF 3516, and AP4 sends TF 3518.

[0379] In by Figure 36 In an alternative embodiment depicted by signaling 3600, potential STAs in UL COBF transmissions can advertise their per-STA information in transmitted frames 3602-3604. The information location within the frames can have a format similar to the AP advertisements discussed above. The scheduler (AP1 in this example) determines the schedule based on the latest advertisement from the advertising STA and sends a multi-AP TF 3606.

[0380] VII-B-3. Method 3: A combination of methods 1 and 2

[0381] The scheduler may query an AP or STA when the scheduler has not received its advertisement recently (e.g., within the last 50 ms). This may save query overhead.

[0382] VII-B-4. Method 4: Based on wired backhaul

[0383] The scheduler can collect candidate STA information from all APs via the wired backhaul. These APs may be located in the same UL COBF cluster.

[0384] VII-C. Reuse of LTF Sequences

[0385] As discussed above, each scheduled STA in an UL COBF transmission can be assigned certain spatial streams. The scheduler can specify the starting stream index and the number of streams per STA. Each stream index corresponds to a temporally orthogonal LTF sequence (e.g., a row in the P matrix) used for UL channel estimation. The LTF sequence assignment can have the following options.

[0386] In the first option (Option 1), each stream uses a different LTF sequence. For example, a total of 6 scheduled streams may require 6 LTF sequences over 6 LTF symbols.

[0387] In the second option (Option 2), if there are disjoint sets of affected APs, streams can reuse the same LTF sequence. If a stream is causing a relatively high RSSI at the AP, then the stream is affecting the AP. This stream can be identified using the candidate STA information described above (e.g., the RSSI caused by the STA for each AP, or the STA's UL Blanking AP ID). Reuse may occur because the affected AP only sees LTFs from the affected stream. Reuse can reduce the total number of LTF sequences, thereby reducing the number of LTF symbols.

[0388] Will refer to Figure 37 3700 describes an example of LTF sequence reuse. In this example, four APs (AP1-AP4) participate in UL COBF reception. Each AP serves one InBSS STA using a single antenna. For example, the first AP AP1 serves STA S1-1, the second AP AP2 serves STA S2-1, and so on. In addition, for the purpose of this discussion, each STA only "affects" two APs: STA S1-1 affects the first AP AP1 and the second AP AP2, STA S2-1 affects the second AP AP2 and the fourth AP AP4, STA S3-1 affects the first AP AP1 and the third AP AP3, and STA S4-1 affects the third AP AP3 and the fourth AP AP4.

[0389] In this case, STAs S1-1 and S4-1 can reuse the same LTF sequence, while STAs S2-1 and S3-1 can reuse other sequences. The total required number of LTF sequences, and therefore the number of LTF symbols, is two. In contrast, no reuse would require four.

[0390] VII-D. Additional Inputs for COBF Scheduling

[0391] The scheduling node can ensure that UL COBF scheduling meets the following feasibility requirements: For each AP that participates in UL COBF reception, the total dimension used by the AP for blanking plus the dimension it serves for InBSS STAs is less than or equal to its total available dimension for UL COBF.

[0392] To check the above requirements, the scheduling node can determine the total available dimension for UL COBF per AP. This information can be obtained via OTA messages. For example, each AP can signal its total dimension for UL COBF in the transmitted frame, for example, in a new "UL COBF Capability" IE in the beacon, or sent together with the candidate STA information.

[0393] VII-E. Limitation on the number of STA reports

[0394] To save overhead, there may be a limit on the number of candidate STAs reported or advertised in methods 1-4 just described. In method 1, this limit may be specified by the querying AP in the query frame. In method 2, this limit may be specified by the cluster leader AP. In method 4, this limit may be specified by the central controller.

[0395] This constraint can take the following forms: The first constraint is the total reported / advertised number of candidate STAs per AP. The second constraint is the maximum total number of supported streams for the reported / advertised number of candidate STAs per AP. The above metrics can be for total candidate STAs, total candidate STAs that need to be blanked, or total candidate STAs that do not need to be blanked.

[0396] VII-F. Cascade Scheduling

[0397] An example of cascade scheduling is given by Figure 38 As shown in the signaling 3800 of . As mentioned above, the previous method describes a scenario where one scheduler makes a scheduling decision. In other implementations, scheduling decisions can be made by all APs in a distributed manner. After obtaining the TXOP, the initiator node ( Figure 38 In the example of FIG, AP1) sends a frame 3802 with scheduling decisions for its own InBSS STAs. This frame indicates the order in which the OBSS APs respond with decisions for their InBSS STAs. The frame also indicates the orthogonal partitioning of the remaining resources among the OBSS APs for both UL COBF transmission and DL ACK (e.g., AP2-AP4 use remaining dimensions 3-4, 5-6, and 7-8 for their InBSS STAs, respectively).

[0398] Each AP responds with scheduling decisions for its own InBSS STAs within the assigned resource range and in the assigned order. Figure 38, AP2 sends its scheduling decision 3804, followed by AP3 sending its scheduling decision 3806, followed by AP4 sending its scheduling decision 3808. Thus, each AP is aware of the decisions of the other APs.

[0399] The last AP's response also triggers individual AP TFs 3810 , 3812 , 3814 and 3816 and UL COBF transmission 3818 .

[0400] VII-G.DL multi-BSS composite frame format

[0401] In some aspects, the present disclosure relates to a composite frame format for COBF. Following are several examples.

[0402] like Figure 39 As shown in signaling 3900, for DL ​​COBF transmission, a composite DL COBF frame may be sent from a participating AP to its STAs. A multi-AP trigger 3902 is sent after a carrier sense multiple access (CSMA) backoff, followed by a composite frame F including a DL COBF transmission 3904 from AP1, a DL COBF transmission 3906 from AP2, a DL COBF transmission 3908 from AP3, and a DL COBF transmission 3910 from AP4. The STA sends a UL ACK 3912 in response to the composite frame F.

[0403] like Figure 40 As shown in signaling 4000, for UL COBF transmissions, a composite DL OFDMA frame can be sent from participating APs to trigger UL transmissions by their STAs. Multi-AP trigger 4002 triggers the transmission of a composite frame F that includes TFs from AP1 to AP4 (represented by TFs 4004 to TF 4006). The STAs transmit UL transmissions in response to composite frame F (represented by transmissions 4008, 4010, to 4012). AP1 to AP4 then acknowledge the UL transmissions (represented by ACKs 4014 to 4106).

[0404] The DL multi-BSS composite frame may have the following options based on how the DL scheduling information of each AP is signaled.

[0405] The first option (Option 1) involves orthogonal scheduling related PHY preambles. Here, the scheduling related PHY preamble can be similar to the SIG-B in the IEEE 802.11ax DL MU-MIMO PPDU. Each AP sends its scheduling information on orthogonal resources.

[0406] The second option (Option 2) involves sharing the scheduling-related PHY preamble. Here, each AP sends the scheduling information of all APs on the same resource.

[0407] VII-G-1. Option 1: Orthogonal Scheduling Preamble

[0408] The DL multi-BSS frame may have four main components. Figure 41 As shown, these components may include a common preamble region 4102, a scheduling-related physical layer (PHY) preamble region 4104, a training symbol region 4106 for training symbols from all APs, and a data region 4108 for data from all APs.

[0409] VII-G-1.a. Components 1: Shared preamble

[0410] All APs may transmit the same common preamble on each 20 MHz channel. For example, all APs transmit the same common preamble on channel 1, all APs transmit the same common preamble on channel 2, all APs transmit the same common preamble on channel 3, and all APs transmit the same common preamble on channel 4. This preamble will be detected by the AP's STAs on the cluster's primary channel and will preserve the entire bandwidth. This preamble may have a fixed size and include information common to all APs. For example, the preamble may include a portion of the L-STF, L-LTF, L-SIG, and 11ax SIG-A information. This may include a format bit (e.g., to indicate a new DL multi-BSS frame), a color bit (e.g., a dedicated cluster color, or the color of the AP that won access), and common frame parameters (e.g., bandwidth, GI+LTF duration, TXOP duration, number of LTFs, number of scheduled preamble symbols and MCS, SR information, Doppler mode, etc.).

[0411] VII-G-1.b. Components 2: Scheduling-related PHY preamble

[0412] An AP may send its scheduling preamble on orthogonal resource units (RUs), which may have variable durations and include information for the AP's own BSS operations. For example, AP1 may send its scheduling preamble 4110 on channel 1, AP2 may send its scheduling preamble 4112 on channel 2, AP3 may send its scheduling preamble 4114 on channel 3, and AP4 may send its scheduling preamble 4116 on channel 4. This information may include DL STA resource allocation and DL reception information (e.g., LDPC additional symbol indicator, pre-FEC filling factor, PE ambiguity indicator). The content of the scheduling preamble may have a format similar to SIG-B. Here, an extension bit may be set to indicate that an additional field is added in addition to the DL resource allocation information. Alternatively, the scheduling preamble may have a new format different from SIG-B.

[0413] A STA may use the following options to determine the RU for its AP's scheduled preamble.

[0414] The first option (Option 1) involves fixed RU allocation. Each cluster member AP has a fixed RU allocation, for example, determined at cluster setup.

[0415] In the second option (Option 2), the RU allocation is signaled in the common preamble.

[0416] The first sub-option of Option 2 (Option 2-1) involves signaling the index of the preconfigured allocation, for example, the index can be a bitmap of the participating AP indices. For example, the bitmap "1110" can mean the first 3 APs in the frame, where the 3 preconfigured RUs are sequentially allocated to them.

[0417] The mapping of indexes to preconfigured allocations may have the following sub-options. One further sub-option (option 2-1-1) relates to a mapping decision made by the standards body (e.g., bitmap "1110" means always use equal RUs for the first three APs). Another further sub-option (option 2-1-2) relates to a mapping based on a table negotiated at cluster setup (e.g., bitmap "1110" in the negotiated table means the first AP has twice as many RUs as the second and third APs).

[0418] The second sub-option (option 2-1) involves signaling dynamic resource allocation information per AP. The dynamic allocation information may include the tone / stream start index and number. The allocation is flexible, but the common preamble may have varying sizes.

[0419] VII-G-1.c. Components 3: Training symbols from all APs

[0420] All APs transmit STF and LTF in the training symbol region 4106. For the case of cross-BSS DL OFDMA, the training symbols of each AP may be only within its allocated subband.

[0421] VII-G-1.d. Components 4: Data from all APs

[0422] All APs transmit data in the data region 4108. The AP may transmit data for each InBSS STA based on the allocation in its scheduling preamble.

[0423] VII-G-2. Option 2: Shared Scheduling Preamble

[0424] Option 2 is the same as option 1, except that the orthogonal scheduling preamble is replaced by a common scheduling preamble 4204, such as in Figure 42As shown in . All APs may send the same common scheduling preamble 4204 on each 20 MHz. For example, all APs send a common scheduling preamble 4210 on channel 1, all APs send a common scheduling preamble 4212 on channel 2, all APs send a common scheduling preamble 4214 on channel 3, and all APs send a common scheduling preamble 4216 on channel 4. The common scheduling preamble contains scheduling information for all APs. No signaling is required to notify the scheduling preamble allocation. There is no change in the AP transmission BW. This approach may be more reliable due to the combined energy from all APs. The common scheduling preamble may be different for different 20 MHz bands (e.g., the preamble only carries scheduling information related to that 20 MHz).

[0425] VIII. Signaling for DL ​​and UL Joint MIMO

[0426] As discussed above, distributed MIMO can take various forms. An example of joint MIMO will be described with reference to Figure 43 Wireless communication system 4300 and Figure 44 Let’s discuss the schedule shown in .

[0427] As discussed above, there may be two categories of STAs: reused STAs and non-reused STAs. Reused STAs are those STAs that have sufficient SINR to be served simultaneously without being blanked.

[0428] For non-reused / edge STAs, any OBSS transmission will degrade the SINR of these STAs. Therefore, these STAs can be time-division multiplexed (TDM) without distributed MIMO. Distributed MIMO allows these STAs to be multiplexed using joint MIMO or using COBF.

[0429] Figure 44 Illustrated is an example of scheduling of baseline CSMA with MU 4402. Since the APs are in the same collision domain, each BSS is time division multiplexed.

[0430] Figure 44 An example of scheduling of COBF 4404 is also illustrated for comparison. This technique creates additional reuse opportunities for non-reused STAs by nulling out dominant interferers. The number of non-reused STAs that can be scheduled depends on the number of unutilized dimensions.

[0431] at last, Figure 44 An example of scheduling for joint MIMO 4406 is illustrated for further comparison. In a TXOP, a cluster (4 APs) can serve N 1-SS STAs, where N is approximately ¾ of the total number of antennas across all 4 APs. The following is an example of signaling that can be used for joint MIMO (similar to the signaling described above).

[0432] The first step involves cluster formation. If we ignore the overhead, it is almost always beneficial to participate in joint MIMO operation, regardless of whether the dimensions of the AP are fully utilized or underutilized. Therefore, no metric is needed to help determine whether clustering is beneficial.

[0433] The second step involves reusing STA identification. This may not be critical for joint MIMO, as each stream consumes one dimension. Therefore, even if a STA does not see all APs, there may be no reuse within the joint MIMO cluster. Potential identification benefits include: in DL joint MIMO, STAs do not need to send BFRPs for unseen APs (but this is not a problem if the UL signal is used for DL ​​sounding), and in UL joint MIMO, STAs affecting disjoint sets of APs can share the same UL LTF sequence.

[0434] The third step involves sounding for DL ​​joint MIMO. If targeting a large number of STAs, UL sounding NDP can save significant overhead (which may also be beneficial for DL ​​COBF). However, periodic calibration may be required to correct for antenna chain phase shifts across APs. Sounding scheduling decision frames (or frames) may be useful for organizing sounding. See the discussion above regarding the signaling of DL COBF sounding scheduling decisions.

[0435] The fourth step involves checking RSSI differences in data transmission scheduling. This step may not be necessary for DL ​​joint MIMO, as all streams sent by all APs can reach each STA with similar RSSI. This step can be used for UL joint MIMO, as the total RSSI per STA received by all APs can vary significantly across STAs.

[0436] The fifth step involves the frame sequence and format used for data transmission. The frame sequence can be similar to DL / UL COBF (e.g., as discussed herein). For DL ​​joint MIMO, the sequence can be a multi-AP TF + DL multi-BSS frame for joint MIMO + UL STA ACK. See the discussion above regarding the signaling of DL COBF scheduling decisions. For UL joint MIMO, the sequence can be a multi-AP TF + DL multi-BSS frame for individual AP TF + UL joint MIMO transmission + DL AP ACK. See the discussion above regarding the signaling of UL COBF scheduling decisions.

[0437] A multi-AP TF may have similar content for scheduling decisions. Alternatively, a central controller may send decisions via the backhaul.

[0438] The DL multi-BSS frame may have a similar format: replicated SIG-A across APs + orthogonal SIG-B. See the discussion of the DL multi-BSS composite frame format above.

[0439] The sixth step involves PHY operations that may not require new MAC signaling. If UL sounding is used in DL joint MIMO, periodic calibration can be used to correct for phase shifts across APs. This phase shift can be estimated from the primary AP's signal (e.g., multi-AP TF or ACK).

[0440] If UL sounding is used in DL joint MIMO, the AP can remove its AGC gain and phase shift on the measured UL channel. The AP can know its actual AGC gain and phase shift through its own offline calibration.

[0441] For data transmission in DL joint MIMO, the AP can remove its phase shift associated with PA adjustment. The AP may know its associated phase shift through its own offline calibration.

[0442] For data transmission in DL joint MIMO, the AP may remove the transmitter phase shift during the data transmission duration.The AP may estimate the frequency offset from the master AP based on the master AP's signal.

[0443] Example Wireless Communication System

[0444] Various wireless technologies and / or various spectrums can be used to implement the teachings herein. Wireless network technologies may include various types of wireless local area networks (WLANs). WLANs can be used to interconnect nearby devices using widely used networking protocols. Various aspects described herein can be applied to any communication standard, such as Wi-Fi, or more generally any member of the IEEE 802.11 wireless protocol family.

[0445] In some aspects, wireless signals may be transmitted in accordance with the 802.11 protocol using orthogonal frequency division multiplexing (OFDM), direct sequence spread spectrum (DSSS) communications, a combination of OFDM and DSSS communications, or other schemes.

[0446] Some of the devices described herein may further implement Multiple Input Multiple Output (MIMO) technology and be implemented as part of the 802.11 protocol. A MIMO system uses multiple (N t ) transmitting antennas and multiple (N r N receiving antennas for data transmission. t emission and N r The MIMO channel composed of N receiving antennas can be decomposed into s independent channels also called spatial channels or streams, where N s ≤min{N t ,N r}. sEach of the 10 independent channels corresponds to a dimension. If the additional dimensionality created by the multiple transmit and receive antennas is utilized, the MIMO system can provide improved performance (eg, higher throughput and / or greater reliability).

[0447] In some implementations, a WLAN includes various devices that access the wireless network. For example, there can be two types of devices: access points ("APs") and clients (also called stations, or "STAs"). Generally speaking, an AP serves as the hub or base station of a WLAN, while a STA serves as a user of the WLAN. For example, a STA can be a laptop computer, a personal digital assistant (PDA), a mobile phone, etc. In one example, a STA connects to an AP via a wireless link compliant with Wi-Fi (e.g., the IEEE 802.11 protocol) to obtain general connectivity to the Internet or other wide area networks. In some implementations, a STA can also function as an AP.

[0448] An access point ("AP") may also include, be implemented as, or be referred to as a transmit reception point (TRP), a NodeB, a radio network controller ("RNC"), an evolved NodeB, a base station controller ("BSC"), a base transceiver station ("BTS"), a base station ("BS"), a transceiver function ("TF"), a radio router, a radio transceiver, or some other term.

[0449] A station "STA" may also include, be implemented as, or be referred to as an access terminal ("AT"), a subscriber station, a subscriber unit, a mobile station, a remote station, a remote terminal, a user terminal, a user agent, a user device, a user equipment, or some other terminology. In some implementations, an access terminal may include, be implemented as, or be referred to as a cellular phone, a cordless phone, a Session Initiation Protocol ("SIP") phone, a wireless local loop ("WLL") station, a personal digital assistant ("PDA"), a handheld device with wireless connectivity, or some other suitable processing device connected to a wireless modem. Thus, one or more aspects taught herein may be incorporated into a phone (e.g., a cellular phone or a smartphone), a computer (e.g., a laptop computer), a portable communication device, a headset, a portable computing device (e.g., a personal data assistant), an entertainment device (e.g., a music or video device, or a satellite radio), a gaming device or system, a global positioning system device, a medical device, a sensor device, or any other suitable device configured to communicate via a wireless medium.

[0450] Figure 45An example of a wireless communication system 4500 in which aspects of the present disclosure may be employed is illustrated. The wireless communication system 4500 may operate in accordance with a wireless standard, such as the 802.11 standard. The wireless communication system 4500 may include an AP 4504 that communicates with STAs 4506a, 4506b, 4506c, 4506d, 4506e, and 4506f (collectively, STAs 4506).

[0451] STAs 4506e and 4506f may have difficulty communicating with AP 4504, or may be out of range of and unable to communicate with AP 4504. As such, another STA 4506d may be configured as a relay device (e.g., a device including STA and AP functionality) that relays communications between AP 4504 and STAs 4506e and 4506f.

[0452] Various procedures and methods can be used for transmissions between the AP 4504 and the STAs 4506 in the wireless communication system 4500. For example, signals can be sent and received between the AP 4504 and the STAs 4506 using OFDM / OFDMA technology. In this case, the wireless communication system 4500 can be referred to as an OFDM / OFDMA system. Alternatively, signals can be sent and received between the AP 4504 and the STAs 4506 using CDMA technology. In this case, the wireless communication system 4500 can be referred to as a CDMA system.

[0453] The communication link that facilitates transmissions from the AP 4504 to one or more STAs 4506 may be referred to as a downlink (DL) 4508, and the communication link that facilitates transmissions from one or more STAs 4506 to the AP 4504 may be referred to as an uplink (UL) 4510. Alternatively, the downlink 4508 may be referred to as a forward link or forward channel, and the uplink 4510 may be referred to as a reverse link or reverse channel.

[0454] The AP 4504 may act as a base station and provide wireless communication coverage in a basic service area (BSA) 4502. The AP 4504, along with the STAs 4506 associated with and communicating using the AP 4504, may be referred to as a basic service set (BSS).

[0455] Access points may thus be deployed in a communication network to provide access to one or more services (e.g., network connectivity) for one or more access terminals that may be installed within or roaming within the coverage area of ​​the network. For example, at various points in time, an access terminal may be connected to AP 4504 or to some other access point (not shown) in the network.

[0456] Each access point can communicate with one or more network entities (for convenience, Figure 45 45. The present invention also provides a method for implementing a wide area network (WAN) that communicates with a plurality of network entities (represented by network entity 4512 in the WAN) (including communicating with each other) to facilitate wide area network connectivity. A network entity may take various forms, such as, for example, one or more radio and / or core network entities. Thus, in various implementations, network entity 4512 may represent functionality such as at least one of: network management (e.g., via an authentication, authorization, and accounting (AAA) server), session management, mobility management, gateway functionality, interworking functionality, database functionality, or some other suitable network functionality. Two or more of such network entities may be co-located and / or two or more of such network entities may be distributed throughout the network.

[0457] It should be noted that in some implementations, the wireless communication system 4500 may not have a central AP 4504, but may instead function as a peer-to-peer network between STAs 4506. Accordingly, the functionality of the AP 4504 described herein may alternatively be performed by one or more STAs 4506. Also, as mentioned above, a relay may incorporate at least some functionality of both the AP and the STAs.

[0458] Figure 46 Illustrated are various components that may be utilized in an apparatus 4602 (e.g., a wireless device) that may be employed within the wireless communication system 4500. The apparatus 4602 is an example of a device that may be configured to implement the various methods described herein. For example, the apparatus 4602 may be employed Figure 45 It may be in the form of an AP 4504, a relay (e.g., STA 4506d), or one of the STAs 4506.

[0459] Device 4602 may include a processing system 4604 that controls the operation of device 4602. Processing system 4604 may also be referred to as a central processing unit (CPU). Memory component 4606 (e.g., including a memory device), which may include both read-only memory (ROM) and random access memory (RAM), provides instructions and data to processing system 4604. A portion of memory component 4606 may also include non-volatile random access memory (NVRAM). Processing system 4604 typically performs logical and arithmetic operations based on program instructions stored within memory component 4606. The instructions in memory component 4606 may be executable to implement the methods described herein.

[0460] When the apparatus 4602 is implemented or used as a transmitting node, the processing system 4604 can be configured to select one of a plurality of media access control (MAC) header types and generate a packet having the MAC header type. For example, the processing system 4604 can be configured to generate a packet including a MAC header and a payload and determine which type of MAC header to use.

[0461] When the apparatus 4602 is implemented or used as a receiving node, the processing system 4604 can be configured to process packets with a variety of different MAC header types. For example, the processing system 4604 can be configured to determine the type of MAC header used in a packet and process the packet and / or fields of the MAC header.

[0462] The processing system 4604 may include, or be a component of, a larger processing system implemented with one or more processors. The one or more processors may be implemented with any combination of general-purpose microprocessors, microcontrollers, digital signal processors (DSPs), field programmable gate arrays (FPGAs), programmable logic devices (PLDs), controllers, state machines, gated logic, discrete hardware components, dedicated hardware finite state machines, or any other suitable entity capable of performing calculations or other manipulations on information.

[0463] The processing system may also include a machine-readable medium for storing software. Software should be broadly interpreted to mean any type of instructions, whether referred to as software, firmware, middleware, microcode, hardware description language, or otherwise. Instructions may include code (e.g., in source code format, binary code format, executable code format, or any other suitable code format). These instructions, when executed by the one or more processors, cause the processing system to perform the various functions described herein.

[0464] Device 4602 may also include a housing 4608, which may include a transmitter 4610 and a receiver 4612 to allow data transmission and reception between device 4602 and a remote location. Transmitter 4610 and receiver 4612 may be combined into a single communication device (e.g., transceiver 4614). Antenna 4616 may be attached to housing 4608 and electrically coupled to transceiver 4614. Device 4602 may also include (not shown) multiple transmitters, multiple receivers, multiple transceivers, and / or multiple antennas. Transmitter 4610 and receiver 4612 may take the form of an integrated device (e.g., a transmitter circuit and a receiver circuit implemented as a single communication device) in some implementations, may take the form of separate transmitter devices and separate receiver devices in some implementations, or may be implemented in other ways in other implementations.

[0465] Transmitter 4610 may be configured to wirelessly transmit packets having different MAC header types. For example, transmitter 4610 may be configured to transmit packets having different header types generated by processing system 4604, as discussed above.

[0466] Receiver 4612 may be configured to wirelessly receive packets having different MAC header types. In some aspects, receiver 4612 is configured to detect the type of MAC header used and process the packet accordingly.

[0467] Receiver 4612 may be configured to detect and quantify the level of a signal received by transceiver 4614. Receiver 4612 may detect signals such as total energy, energy per symbol per subcarrier, power spectral density, and other signals. Apparatus 4602 may also include a digital signal processor (DSP) 4620 for processing signals. DSP 4620 may be configured to generate data units for transmission. In some aspects, the data units may be physical layer data units (PPDUs). In some aspects, PPDUs are referred to as packets.

[0468] In some aspects, device 4602 may further include a user interface 4622. User interface 4622 may include a keypad, a microphone, a speaker, and / or a display. User interface 4622 may include any element or component that conveys information to a user of device 4602 and / or receives input from the user.

[0469] The various components of device 4602 can be coupled together by a bus system 4626. Bus system 4626 can include, for example, a data bus, as well as a power bus, a control signal bus, and a status signal bus in addition to the data bus. Those skilled in the art will appreciate that the various components of device 4602 can be coupled together or use some other mechanism to receive or provide input from each other.

[0470] although Figure 46 4604, but one or more of these components may be combined or implemented together. For example, the processing system 4604 may be used to implement not only the functionality described above with respect to the processing system 4604, but also the functionality described above with respect to the transceiver 4614 and / or the DSP 4620. In addition, Figure 46 Each component illustrated in the can be implemented using multiple separate elements. In addition, the processing system 4604 can be used to implement any one of the components, modules, circuits, or the like described below, or each can be implemented using multiple separate elements.

[0471] For ease of reference, when apparatus 4602 is configured as a transmitting node, it is referred to as apparatus 4602t hereinafter. Similarly, when apparatus 4602 is configured as a receiving node, it is referred to as apparatus 4602r hereinafter. Devices in wireless communication system 4500 may implement only the functionality of a transmitting node, only the functionality of a receiving node, or both the functionality of a transmitting node and a receiving node.

[0472] As discussed above, the device 4602 may take the form of an AP 4504 or a STA 4506 and may be used to transmit and / or receive communications having a variety of MAC header types.

[0473] Figure 46 The components of can be implemented in various ways. In some implementations, Figure 46 The components of may be implemented in one or more circuits, such as, for example, one or more processors and / or one or more ASICs (which may include one or more processors). Here, each circuit may use and / or incorporate at least one memory component for storing information or executable code used by the circuit to provide this functionality. For example, Figure 46 Some or all of the functionalities represented by the various blocks of FIG may be implemented by the processor and memory components of the device (e.g., by executing appropriate code and / or by appropriately configuring the processor components). It should be appreciated that these components may be implemented in different types of devices (e.g., ASICs, system-on-chip (SoC), etc.) in different implementations.

[0474] As discussed above, the device 4602 may take the form of an AP 4504, a STA 4506, a relay, or some other type of device, and may be used to transmit and / or receive communications. Figure 47 Illustrated are various components that may be utilized in device 4602t to transmit wireless communications. Figure 47 The components illustrated in can be used, for example, to transmit OFDM communications. In some aspects, Figure 47 The components illustrated in are used to generate and transmit packets to be sent over a bandwidth less than or equal to 1 MHz.

[0475] Figure 47 The device 4602t may include a modulator 4702 configured to modulate bits for transmission. For example, the modulator 4702 may receive bits from the processing system 4604 ( Figure 46 ) or user interface 4622 ( Figure 46) bits to determine multiple symbols. These bits may correspond to user data or control information. In some aspects, these bits are received in codewords. In one aspect, modulator 4702 may include a QAM (quadrature amplitude modulation) modulator, such as a 16-QAM modulator or a 64-QAM modulator. In other aspects, modulator 4702 may include a binary phase shift keying (BPSK) modulator, a quadrature phase shift keying (QPSK) modulator, or an 8-PSK modulator.

[0476] The apparatus 4602t may further include a transform module 4704 configured to convert the symbols or otherwise modulated bits from the modulator 4702 into the time domain. Figure 47 , the transform module 4704 is illustrated as being implemented by an inverse fast Fourier transform (IFFT) module. In some implementations, there may be multiple transform modules (not shown) that transform data units of different sizes. In some implementations, the transform module 4704 itself may be configured to transform data units of different sizes. For example, the transform module 4704 may be configured with multiple modes, and a different number of points may be used in each mode to transform codewords. For example, the IFFT may have a mode in which 32 points are used to convert codewords being transmitted on 32 frequency tones (i.e., subcarriers) into the time domain, and a mode in which 64 points are used to convert codewords being transmitted on 64 frequency tones into the time domain. The number of points used by the transform module 4704 may be referred to as the size of the transform module 4704.

[0477] exist Figure 47 4704 are illustrated as being implemented in the DSP 4720. However, in some aspects, one or both of the modulator 4702 and the transform module 4704 are implemented in the processing system 4604 or in another element of the device 4602t (e.g., see above with reference to FIG. Figure 46 description).

[0478] As discussed above, the DSP 4720 may be configured to generate a data unit for transmission.In some aspects, the modulator 4702 and the transform module 4704 may be configured to generate a data unit comprising a plurality of fields including control information and a plurality of data symbols.

[0479] Back to Figure 47 As described above, the device 4602t may further include a digital-to-analog converter (D / A) 4706 configured to convert the output of the transform module into an analog signal. For example, the time domain output of the transform module 4704 may be converted into a baseband OFDM signal by the D / A converter 4706. The D / A converter 4706 may be implemented in Figure 46In some aspects, the digital-to-analog converter 4706 is implemented in the transceiver 4614 ( Figure 46 ) or in a data transmission processor.

[0480] The analog signal may be transmitted wirelessly by the transmitter 4710. The analog signal may be further processed, such as filtered or up-converted to an intermediate frequency or carrier frequency, before being transmitted by the transmitter 4710. Figure 47 , transmitter 4710 includes a transmit amplifier 4708. Prior to being transmitted, the analog signal may be amplified by the transmit amplifier 4708. In some aspects, the amplifier 4708 may include a low noise amplifier (LNA).

[0481] The transmitter 4710 is configured to transmit one or more packets or data units in a wireless signal based on the analog signal. These data units may be processed using the processing system 4604 ( Figure 46 ) and / or DSP 4720, for example, using the modulator 4702 and transform module 4704 discussed above. Data units that may be generated and transmitted as discussed above are described in more detail below.

[0482] Figure 48 Explanation available in Figure 46 Various components of device 4602 for receiving wireless communications. Figure 48 The components illustrated in can be used, for example, to receive OFDM communications. For example, Figure 48 The components described in the foregoing may be used to receive Figure 47 The unit of data transferred by the component in question.

[0483] The receiver 4812 of the device 4602r is configured to receive one or more packets or data units in a wireless signal. The data units may be received and decoded or otherwise processed as discussed below.

[0484] exist Figure 48 In the aspects illustrated in FIG. 4 , receiver 4812 includes a receive amplifier 4801. Receive amplifier 4801 may be configured to amplify wireless signals received by receiver 4812. In some aspects, receiver 4812 is configured to adjust the gain of receive amplifier 4801 using an automatic gain control (AGC) procedure. In some aspects, the automatic gain control uses information in one or more received training fields, such as, for example, a received short training field (STF), to adjust the gain. Methods for performing AGC will be understood by those of ordinary skill in the art. In some aspects, amplifier 4801 may include an LNA.

[0485] Device 4602r may include an analog-to-digital converter 4810 configured to convert the amplified wireless signal from receiver 4812 into a digital representation thereof. Following amplification, the wireless signal may be processed, such as by being filtered or downconverted to an intermediate frequency or baseband frequency, before being converted by analog-to-digital converter 4810. Analog-to-digital converter 4810 may be implemented in processing system 4604 ( Figure 46 ) or implemented in another element of the device 4602r. In some aspects, the analog-to-digital converter 4810 is implemented in the transceiver 4614 ( Figure 46 ) or in a data receiving processor.

[0486] The apparatus 4602r may further comprise a transform module 4804 configured to transform the representation of the wireless signal into a frequency spectrum. Figure 48 , the transform module 4804 is illustrated as being implemented by a Fast Fourier Transform (FFT) module. In some aspects, the transform module may identify a symbol for each point it uses. Figure 47 As described, the transform module 4804 can be configured with multiple modes and can use a different number of points to transform the signal in each mode. The number of points used by the transform module 4804 can be referred to as the size of the transform module 4804. In some aspects, the transform module 4804 can identify the codeword for each point it uses.

[0487] The apparatus 4602r may further include a channel estimator and equalizer 4805 configured to form an estimate of the channel over which the data unit is received and to remove certain effects of the channel based on the channel estimate. For example, the channel estimator and equalizer 4805 may be configured to approximate a function of the channel, and the channel equalizer may be configured to apply an inverse of the function to the data in the frequency spectrum.

[0488] The apparatus 4602r may further include a demodulator 4806 configured to demodulate the equalized data. For example, the demodulator 4806 may determine a plurality of bits from the symbols output by the transform module 4804 and the channel estimator and equalizer 4805, for example by reversing the mapping of bits to symbols in the constellation. These bits may be processed by the processing system 4604 ( Figure 46 ) is processed or evaluated, or is used to provide user interface 4622 ( Figure 46) displays information or otherwise outputs information to it. In this way, data and / or information can be decoded. In some aspects, these bits correspond to codewords. In one aspect, demodulator 4806 may include a QAM (quadrature amplitude modulation) demodulator, such as an 8-QAM demodulator or a 64-QAM demodulator. In other aspects, demodulator 4806 may include a binary phase shift keying (BPSK) demodulator or a quadrature phase shift keying (QPSK) demodulator.

[0489] exist Figure 48 48, the transform module 4804, the channel estimator and equalizer 4805, and the demodulator 4806 are illustrated as being implemented in the DSP 4820. However, in some aspects, one or more of the transform module 4804, the channel estimator and equalizer 4805, and the demodulator 4806 are implemented in the processing system 4604 ( Figure 46 ) or in device 4602 ( Figure 46 ) is implemented in another element.

[0490] As discussed above, the wireless signal received at receiver 4612 may include one or more data units. Using the functions or components described above, the data units or data symbols therein may be decoded, evaluated, or otherwise evaluated or processed. For example, processing system 4604 ( Figure 46 ) and / or DSP 4820 can be used to decode data codewords in a data unit using a transform module 4804, a channel estimator and equalizer 4805, and a demodulator 4806.

[0491] The data units exchanged by AP 4504 and STA 4506 may include control information or data, as discussed above. At the physical (PHY) layer, these data units may be referred to as physical layer protocol data units (PPDUs). In some aspects, a PPDU may be referred to as a packet or physical layer packet. Each PPDU may include a preamble and a payload. The preamble may include a training field and a SIG field. The payload may include, for example, a media access control (MAC) header or data from other layers, and / or user data. The payload may be transmitted using one or more data symbols. The systems, methods, and apparatus herein may utilize data units with training fields whose peak power ratio has been minimized.

[0492] Figure 47 The device 4602t shown in FIG. 4 is an example of a single transmit chain for transmitting via an antenna. Figure 48 The device 4602r shown in FIG is an example of a single receive chain for receiving via an antenna. In some implementations, the device 4602t or 4602r may implement a portion of a MIMO system that uses multiple antennas to transmit data simultaneously.

[0493] The wireless communication network 4500 may employ a method based on unpredictable data transmission to allow efficient access to the wireless medium while avoiding collisions. Thus, according to various aspects, the wireless communication system 4500 implements Carrier Sense Multiple Access / Collision Avoidance (CSMA / CA), which may be referred to as a Distributed Coordination Function (DCF). More generally, a device 4602 having data for transmission senses the wireless medium to determine whether the channel is occupied. If the device 4602 senses that the channel is idle, the device 4602 transmits the prepared data. Otherwise, the device 4602 may delay for a certain period of time before again determining whether the wireless medium is idle for transmission. A method for implementing CSMA may employ various gaps between successive transmissions to avoid collisions. In one aspect, the transmission may be referred to as a frame, and the gap between frames is referred to as an interframe space (IFS). Each frame may be any of user data, control frames, management frames, and the like.

[0494] The IFS time duration may vary depending on the type of time gap provided. Some examples of IFS include short interframe space (SIFS), point interframe space (PIFS), and DCF interframe space (DIFS), where SIFS is shorter than PIFS, which is shorter than DIFS. Transmissions following a shorter time duration will have a higher priority than transmissions that must wait longer before attempting to access the channel.

[0495] A wireless device may include various components that perform functions based on signals transmitted by or received at the wireless device. For example, in some implementations, the wireless device may include a user interface configured to output an indication based on a received signal, as taught herein.

[0496] A wireless device as taught herein may communicate via one or more wireless communication links that are based on or otherwise support any suitable wireless communication technology. For example, in some aspects, a wireless device may be associated with a network such as a local area network (e.g., a Wi-Fi network) or a wide area network. To this end, the wireless device may support or otherwise utilize one or more of a variety of wireless communication technologies, protocols, or standards (such as, for example, Wi-Fi, WiMAX, CDMA, TDMA, OFDM, and OFDMA). Similarly, the wireless device may support or otherwise utilize one or more of a variety of corresponding modulation or multiplexing schemes. The wireless device may thus include appropriate components (e.g., air interfaces) to establish one or more wireless communication links using the above or other wireless communication technologies and communicate via the one or more wireless communication links. For example, a device may include a wireless transceiver with associated transmitter and receiver components that may include various components (e.g., signal generators and signal processors) that facilitate communication over a wireless medium.

[0497] The teachings herein may be incorporated into (e.g., implemented within or performed by) various devices (e.g., nodes). In some aspects, a device (e.g., a wireless device) implemented according to the teachings herein may comprise an access point, a relay, or an access terminal.

[0498] An access terminal may include, be implemented as, or be referred to as, user equipment, a subscriber station, a subscriber unit, a mobile station, a mobile station, a mobile node, a remote station, a remote terminal, a user terminal, a user agent, a user device, or other terminology. In some implementations, an access terminal may take the form of a cellular phone, a cordless phone, a Session Initiation Protocol (SIP) phone, a wireless local loop (WLL) station, a personal digital assistant (PDA), a handheld device with wireless connection capabilities, or some other suitable processing device connected to a wireless modem. Accordingly, one or more aspects taught herein may be incorporated into a phone (e.g., a cellular phone or a smart phone), a computer (e.g., a laptop), a portable communication device, a portable computing device (e.g., a personal data assistant), an entertainment device (e.g., a music device, a video device, or a satellite radio), a global positioning system device, or any other suitable device configured to communicate via a wireless medium.

[0499] An access point may include, be implemented as, or be referred to as, a NodeB, an evolved NodeB, a radio network controller (RNC), a base station (BS), a radio base station (RBS), a base station controller (BSC), a base transceiver station (BTS), a transceiver function (TF), a radio transceiver, a radio router, a basic service set (BSS), an extended service set (ESS), a macro cell, a macro node, a home evolved NodeB (HeNB), a femto cell, a femto node, a pico node, or some other similar terminology.

[0500] A relay may include, be implemented as, or be referred to as a relay node, a relay device, a relay station, a relay apparatus, or some other similar term.As discussed above, in some aspects a relay may include some access terminal functionality and some access point functionality.

[0501] In some aspects, a wireless device may comprise an access device (e.g., an access point) of a communication system. Such an access device provides connectivity to another network (e.g., a wide area network such as the Internet or a cellular network), for example, via a wired or wireless communication link. Thus, the access device enables another device (e.g., a wireless station) to access other networks or some other functionality. It should also be appreciated that one or both of these devices may be portable or, in some cases, relatively non-portable. It should also be appreciated that the wireless device may also be capable of transmitting and / or receiving information in a non-wireless manner (e.g., via a wired connection) via an appropriate communication interface.

[0502] The teachings of this article can be incorporated into various types of communication systems and / or system components. In some aspects, the teachings of this article can be used in a multiple access system that can support communication with multiple users by sharing available system resources (e.g., by specifying one or more of bandwidth, transmit power, coding, interleaving, etc.). For example, the teachings of this article can be applied to any one of the following technologies or a combination thereof: code division multiple access (CDMA) system, multi-carrier CDMA (MCCDMA), wideband CDMA (W-CDMA), high-speed packet access (HSPA, HSPA+) system, time division multiple access (TDMA) system, frequency division multiple access (FDMA) system, single carrier FDMA (SC-FDMA) system, orthogonal frequency division multiple access (OFDMA) system, or other multiple access technologies. A wireless communication system using the teachings of this article can be designed to implement one or more standards, such as IS-95, cdma2000, IS-856, W-CDMA, TDSCDMA, and other standards. A CDMA network can implement a radio technology such as Universal Terrestrial Radio Access (UTRA), cdma2000, or some other technology. UTRA includes W-CDMA and Low Chip Rate (LCR). cdma2000 technology covers IS-2000, IS-95 and IS-856 standards. TDMA networks can implement radio technologies such as Global System for Mobile Communications (GSM). OFDMA networks can implement radio technologies such as Evolved UTRA (E-UTRA), IEEE 802.11, IEEE 802.16, IEEE 802.20, Radio technologies such as UTRA, E-UTRA, and GSM are part of the Universal Mobile Telecommunications System (UMTS). The teachings herein can be implemented in 3GPP Long Term Evolution (LTE) systems, Ultra Mobile Broadband (UMB) systems, and other types of systems. LTE is a version of UMTS that uses E-UTRA. UTRA, E-UTRA, GSM, UMTS, and LTE are described in documents from an organization called the 3rd Generation Partnership Project (3GPP), while cdma2000 is described in documents from an organization called the 3rd Generation Partnership Project 2 (3GPP2). Although certain aspects of the present disclosure may be described using 3GPP terminology, it should be understood that the teachings herein are applicable to 3GPP (e.g., Rel (Release) 99, Rel 5, Rel 6, Rel 7) technologies as well as 3GPP2 (e.g., 1xRTT, 1xEV-DO Rel 0, Rev (Revision) A, Rev B) technologies and other technologies.

[0503] Example Communication Device

[0504] Figure 49 An example apparatus 4900 (e.g., an AP, an AT, or some other type of wireless communication node) in accordance with certain aspects of the present disclosure is illustrated. The apparatus 4900 includes an apparatus 4902 (e.g., an integrated circuit) and may optionally include at least one other component 4908. In some aspects, the apparatus 4902 may be configured to operate in a wireless communication node (e.g., an AP or an AT) and perform one or more operations described herein. For convenience, a wireless communication node may be referred to herein as a wireless node. In different scenarios, a wireless node may be an AP, a STA, a central dispatcher, or some other type of communication node. The apparatus 4902 includes a processing system 4904 and a memory 4906 coupled to the processing system 4904. An example implementation of the processing system 4904 is provided herein. In some aspects, Figure 49 The processing system 4904 and memory 4906 may correspond to Figure 46 processing system 4604 and memory component 4606.

[0505] The processing system 4904 is generally adapted for processing, including executing such programming stored on the memory 4906. For example, the memory 4906 may store instructions that, when executed by the processing system 4904, cause the processing system 4904 to perform one or more operations described herein. As used herein, the terms "programming" or "instructions" or "code" should be interpreted broadly to include, without limitation, instruction sets, instructions, data, code, code segments, program code, programs, programming, subroutines, software modules, applications, software applications, software packages, routines, subroutines, objects, executables, threads of execution, procedures, functions, and the like, whether referred to as software, firmware, middleware, microcode, hardware description language, or otherwise.

[0506] In some implementations, the device 4902 communicates with at least one other component 4908 of the device 4900 (i.e., a component external to the device 4902). To this end, in some implementations, the device 4902 may include at least one interface 4910 (e.g., a transmit / receive interface) coupled to the processing system 4904 for outputting and / or obtaining (e.g., sending and / or receiving) information (e.g., received information, generated information, decoded information, messages, etc.) between the processing system 4904 and the at least one other component 4908. In some implementations, the at least one interface 4910 may include an interface bus, a bus driver, a bus receiver, other suitable circuitry, or a combination thereof. In some implementations, the at least one interface 4910 may include radio frequency (RF) circuitry (e.g., an RF transmitter and / or an RF receiver). In some implementations, the at least one interface 4910 may be configured to connect the device 4902 to one or more other components (e.g., an RF transmitter and / or an RF receiver) of the device 4900. Figure 49 4904 and / or other components not shown). For example, at least one interface 4910 can be configured to interface the processing system 4904 with a radio frequency (RF) front end (e.g., an RF transmitter and / or an RF receiver). In some implementations, the interface can include multiple interfaces. For example, a bidirectional interface can include a first interface for acquisition and a second interface for output.

[0507] Device 4902 can communicate with other devices in various ways. Figure 49In some cases (not shown), the device 4902 may transmit and receive information (e.g., frames, messages, bits, etc.) via RF signaling. In some cases, the device 4902 may have an interface that provides (e.g., outputs, sends, transmits, etc.) information for RF transmission, rather than transmitting information via RF signaling. For example, the processing system 4904 may output information to the RF front end via a bus interface for RF transmission. Similarly, the device 4902 may have an interface that obtains information received by another device, rather than receiving information via RF signaling. For example, the processing system 4904 may obtain (e.g., receive) information via the bus interface from an RF receiver that receives information via RF signaling.

[0508] Example Process

[0509] Figure 50 An example process 5000 for communication according to some aspects of the present disclosure is illustrated. The process 5000 may be performed on a processing system (e.g., Figure 49 The processing circuit may be located in an AP, a STA, or some other suitable device. Of course, in various aspects within the scope of the present disclosure, the process 5000 may be implemented by any suitable device capable of supporting communication-related operations.

[0510] At block 5002, an apparatus (e.g., an AP or some other node) obtains signal measurement information indicating channel conditions between a plurality of first wireless nodes (e.g., APs) and a plurality of second wireless nodes (e.g., STAs). In some aspects, the plurality of first wireless nodes may comprise at least a portion of a cluster of wireless nodes configured to collectively serve the plurality of second wireless nodes. In some aspects, the cluster may comprise a coordinated beamforming cluster or a joint multiple-input multiple-output (MIMO) cluster.

[0511] In different scenarios, the signal measurement information may take different forms. In some aspects, the signal measurement information may include at least one received signal strength indicator (RSSI). In some aspects, the signal measurement information may include at least one signal-to-interference and noise ratio (SINR). In some aspects, the signal measurement information may be for at least one uplink signal, at least one downlink signal, or any combination thereof.

[0512] In some aspects, the signal measurement information may include a result of at least one beacon signal measurement. Furthermore, obtaining may include obtaining the result of at least one beacon signal measurement. In some aspects, process 5000 may further include the apparatus generating a request for the plurality of second wireless nodes to measure a beacon signal from each of the plurality of first wireless nodes, and outputting the request (e.g., for transmission to an access point of the cluster). In this case, the result of the at least one beacon signal measurement may be obtained after outputting the request.

[0513] In some aspects, the signal measurement information may include a result of at least one sounding measurement. Furthermore, obtaining may include obtaining the result of the at least one sounding measurement. In some aspects, process 5000 may further include the apparatus generating a request for the plurality of second wireless nodes to perform a sounding measurement with each of the plurality of first wireless nodes, and outputting the request (e.g., for transmission to an access point of the cluster). In this case, the result of the at least one sounding measurement may be obtained after outputting the request.

[0514] In some aspects, the signal measurement information may include a result of at least one uplink signal measurement. Furthermore, obtaining may include obtaining the result of at least one uplink signal measurement. In some aspects, process 5000 may further include the apparatus generating a request for the plurality of second wireless nodes to transmit an uplink signal to each of the plurality of first wireless nodes, and outputting the request (e.g., for transmission to an access point of the cluster). In this case, the result of the at least one uplink signal measurement may be obtained after outputting the request.

[0515] In some aspects, at least one second wireless node in the plurality of second wireless nodes may be associated with a first wireless node in the plurality of first wireless nodes. In some aspects, at least one second wireless node in the plurality of second wireless nodes may be a basic service set.

[0516] At block 5004, the apparatus determines which first wireless node of a plurality of first wireless nodes is to perform a blanking operation for one or more second wireless nodes of a plurality of second wireless nodes, wherein the determination is based on the obtained signal measurement information.

[0517] At block 5006 , the apparatus generates a list identifying each first wireless node in the plurality of first wireless nodes for which to perform a blanking operation on a particular second wireless node in the plurality of second wireless nodes, wherein generation of the list is based on the determination of block 5004 .

[0518] At box 5008, the device outputs the list for transmission.

[0519] Figure 51 An example process 5100 for communicating according to some aspects of the present disclosure is illustrated. The process 5100 may be performed on a processing system (e.g., Figure 49 The processing circuit may be located in an AP, a STA, or some other suitable device. Of course, in various aspects within the scope of the present disclosure, the process 5100 may be implemented by any suitable device capable of supporting communication-related operations.

[0520] At block 5102, a device (e.g., an AP, a STA, or some other node) obtains, for each of a plurality of first wireless nodes in a cluster of first wireless nodes, signal measurement information about at least one second wireless node. In some aspects, the signal measurement information may include at least one received signal strength indication (RSSI), at least one signal to interference and noise ratio (SINR), or any combination thereof. In some aspects, the signal measurement information may be reported by the at least one second wireless node to an associated one of the plurality of first wireless nodes in the cluster. In some aspects, the cluster may include a coordinated beamforming cluster or a joint multiple-input multiple-output (MIMO) cluster.

[0521] At block 5104, the apparatus generates an indication based on the signal measurement information. In some aspects, the indication may include the signal measurement information, an identifier of the access point for which blanking is to be performed, or some other information.

[0522] At block 5106 , the apparatus outputs an indication (eg, for transmission to at least one access point).

[0523] In some aspects, process 5100 may further include the apparatus generating a packet including a medium access control (MAC) header having an efficient control field including an indication or a management frame including an indication. Additionally, outputting the indication may include outputting the packet.

[0524] In some aspects, process 5100 may further include the apparatus determining whether at least one first wireless node among the plurality of first wireless nodes is to generate at least one blanking signal for at least one second wireless node. In some aspects, the determination may be based on signal measurement information. Furthermore, generating the indication may include including at least one identifier of the at least one first wireless node among the plurality of first wireless nodes in the indication.

[0525] In some aspects, the at least one second wireless node may include a plurality of second wireless nodes in the set of second wireless nodes that are served by a first first wireless node in the plurality of first wireless nodes. Furthermore, the apparatus may output an indication for transmission to at least a second first wireless node in the plurality of first wireless nodes. In some aspects, the second set of wireless nodes may include a basic service set.

[0526] In some aspects, process 5100 may include an apparatus obtaining additional signal measurement information from at least a second first wireless node in the plurality of first wireless nodes and generating a transmission schedule based on the additional signal measurement information. In some aspects, the additional signal measurement information may relate to at least one other second wireless node associated with the at least second first wireless node in the plurality of first wireless nodes. In some aspects, transmission of the signal measurement information from a first first wireless node in the plurality of first wireless nodes to the at least second first wireless node in the plurality of first wireless nodes may be scheduled by one of the plurality of first wireless nodes in the cluster.

[0527] In some aspects, process 5100 may further include the apparatus obtaining a request to measure a beacon signal from each of the plurality of first wireless nodes in the cluster. In some aspects, obtaining the signal measurement may include measuring a beacon signal from each of the plurality of first wireless nodes in the cluster. In some aspects, outputting the indication for transmission may include outputting the measurement of the beacon signal.

[0528] In some aspects, process 5100 may further include obtaining, by the apparatus, a request to perform a sounding measurement with each of the plurality of first wireless nodes in the cluster. In some aspects, obtaining the signal measurement may include performing a sounding measurement with each of the plurality of first wireless nodes in the cluster. In some aspects, outputting the indication for transmission may include outputting a result of the sounding measurement based on the sounding measurement.

[0529] In some aspects, process 5100 may further include the device obtaining a request to transmit an uplink signal to each of a plurality of first wireless nodes in the cluster, and outputting an uplink signal for transmission to each of the plurality of first wireless nodes in the cluster after obtaining the request.

[0530] Figure 52 An example process 5200 for communication according to some aspects of the present disclosure is illustrated. The process 5200 may be performed on a processing system (e.g., Figure 49 The processing circuit may be located in an AP, a STA, or some other suitable device. Of course, in various aspects within the scope of the present disclosure, the process 5200 may be implemented by any suitable device capable of supporting communication-related operations.

[0531] At block 5202, an apparatus (e.g., an AP or some other node) identifies a plurality of first wireless nodes to be scheduled for a channel sounding operation, wherein the plurality of first wireless nodes are members of a first cluster of wireless nodes. In some aspects, the cluster may comprise a coordinated beamforming cluster or a joint multiple-input multiple-output (MIMO) cluster.

[0532] At block 5204, the apparatus identifies a plurality of second wireless nodes to be scheduled for a channel sounding operation, wherein a first second wireless node in the plurality of second wireless nodes is served by a first first wireless node in the plurality of first wireless nodes and a second second wireless node in the plurality of second wireless nodes is served by a second first wireless node in the plurality of first wireless nodes. In some aspects, identifying the plurality of second wireless nodes may include identifying a wireless node to measure each individual null data packet (NDP) sent by at least one first wireless node in the plurality of first wireless nodes.

[0533] At block 5206, the apparatus generates a sounding schedule including identifiers for the identified plurality of first wireless nodes and the identified plurality of second wireless nodes.

[0534] In some aspects, the sounding scheduling may include: an order in which the plurality of first wireless nodes are to send corresponding null data packets (NDPs), a beamforming report (BFRP) configuration for each of the plurality of second wireless nodes, a frequency modulation group number for each of the plurality of second wireless nodes, a codebook size for each of the plurality of second wireless nodes, a null data packet (NDP) configuration for each of the plurality of first wireless nodes, an NDP bandwidth for each of the plurality of first wireless nodes, a number of sounding streams for each of the plurality of first wireless nodes, or any combination thereof.

[0535] At block 5208, the apparatus outputs a sounding schedule (eg, for transmission to the access points of the cluster).

[0536] In some aspects, process 5200 may further include the apparatus generating a schedule frame including the sounding schedule therein. In some aspects, outputting the sounding schedule may include outputting the schedule frame for transmission at the beginning of the sounding sequence.

[0537] In some aspects, process 5200 may further include the apparatus generating a Null Data Packet Announcement (NDPA) frame including the sounding schedule therein. In some aspects, outputting the sounding schedule may include outputting the NDPA frame for transmission at the beginning of the sounding sequence.

[0538] In some aspects, process 5200 may further include the apparatus generating a sounding trigger and schedule frame including the sounding schedule. In some aspects, outputting the sounding schedule may include outputting the sounding trigger and schedule frame for transmission at the beginning of the sounding sequence.

[0539] In some aspects, process 5200 may further include the apparatus obtaining information for the identification of a plurality of first wireless nodes, a plurality of second wireless nodes, or any combination thereof. In some aspects, process 5200 may further include the apparatus outputting at least one query for transmission, wherein the at least one query solicits information from the plurality of first wireless nodes. In some aspects, the at least one query may indicate at least one resource to be used per response, and the at least one resource may include at least one subband, at least one spatial stream, at least one time slot, or any combination thereof. In some aspects, process 5200 may further include the apparatus outputting at least one query for transmission, wherein the at least one query solicits information from the plurality of second wireless nodes. In some aspects, obtaining information may include obtaining autonomous advertisements comprising information from the plurality of first wireless nodes. In some aspects, obtaining information may include obtaining autonomous advertisements comprising information from the plurality of second wireless nodes.

[0540] In some aspects, the information may include: a second wireless node identifier per basic service set (BSS) of any second wireless node from the plurality of second wireless nodes that is a candidate for distributed multiple-input multiple-output (MIMO) data reception within the cluster, a second wireless node identifier of any second wireless node from the plurality of second wireless nodes that has data to send, a first wireless node identifier of any first wireless node from the plurality of first wireless nodes that is a candidate for performing a nulling operation for at least one second wireless node from the plurality of second wireless nodes, capability information for distributed MIMO sounding for at least one second wireless node from the plurality of second wireless nodes, or any combination thereof.

[0541] Figure 53 Illustrated is an example process 5300 for communicating according to some aspects of the present disclosure. The process 5300 can be performed on a processing system (e.g., Figure 49 The processing circuit may be located in an AP, a STA, or some other suitable device. Of course, in various aspects within the scope of the present disclosure, process 5300 may be implemented by any suitable device capable of supporting communication-related operations.

[0542] At block 5302, an apparatus (e.g., an AP or some other node) identifies a plurality of first wireless nodes, wherein the plurality of first wireless nodes are members of a first wireless node cluster. In some aspects, identifying the plurality of first wireless nodes may include, for each of the plurality of first wireless nodes in the first wireless node cluster, determining whether the first wireless node has sufficient dimensions to serve at least one second wireless node in a basic service set of the first wireless node and to blank any second wireless nodes in the plurality of second wireless nodes that are not in the basic service set of the first wireless node and that need to be blanked for distributed MIMO communication. In some aspects, the cluster may include a coordinated beamforming cluster or a joint multiple-input multiple-output (MIMO) cluster.

[0543] At block 5304, the apparatus identifies a plurality of second wireless nodes, wherein a first second wireless node in the plurality of second wireless nodes is served by a first first wireless node in the plurality of first wireless nodes, and a second second wireless node in the plurality of second wireless nodes is served by a second first wireless node in the plurality of first wireless nodes. In some aspects, identifying the plurality of second wireless nodes may include, for each first wireless node in the plurality of first wireless nodes, identifying at least one second wireless node in the plurality of second wireless nodes that is in a basic service set of the first wireless node and is served by the first wireless node and has data to transmit. In some aspects, identifying the plurality of second wireless nodes may include, for each first wireless node in the plurality of first wireless nodes, identifying at least one second wireless node in the plurality of second wireless nodes that is not in a basic service set of the first wireless node and is left unfilled by the first wireless node.

[0544] At block 5306, the apparatus generates a communication schedule for distributed multiple-input multiple-output (MIMO) communication (e.g., downlink transmission or uplink transmission), wherein the communication schedule includes identifiers of the plurality of first wireless nodes and identifiers of the plurality of second wireless nodes. In some aspects, the distributed MIMO communication may include coordinated beamforming (COBF) communication or joint multiple-input multiple-output (MIMO) communication.

[0545] In some aspects, the communication schedule may include trigger frame scheduling information for a plurality of first wireless nodes. In some aspects, the trigger frame scheduling information may include: an identifier for each of the plurality of first wireless nodes, at least one trigger frame resource allocation for each of the plurality of first wireless nodes, at least one start stream index for each of the plurality of first wireless nodes, at least one stream number for each of the plurality of first wireless nodes, at least one time slot for each of the plurality of first wireless nodes, at least one subband for each of the plurality of first wireless nodes, at least one modulation and coding scheme (MCS) for each of the plurality of first wireless nodes, a duration for at least one trigger frame transmission, at least one bandwidth for at least one trigger frame transmission, or any combination thereof.

[0546] In some aspects, the communication schedule may include: a second wireless node identifier for each of a plurality of second wireless nodes, at least one distributed MIMO communication resource allocation for each of the plurality of second wireless nodes, at least one identifier of at least one first wireless node of a plurality of first wireless nodes scheduled to perform a nulling operation for at least one of the plurality of second wireless nodes, at least one received signal strength indication (RSSI) at each of the plurality of first wireless nodes, a duration of the distributed MIMO communication, at least one bandwidth for the distributed MIMO communication, or any combination thereof.

[0547] In some aspects, the communication schedule may include: at least one starting stream index for each of the plurality of second wireless nodes, at least one stream number for each of the plurality of second wireless nodes, at least one modulation and coding scheme (MCS) for each of the plurality of second wireless nodes, at least one identifier of at least one first wireless node of the plurality of first wireless nodes that is not scheduled to perform a nulling operation for at least one of the plurality of second wireless nodes, or any combination thereof.

[0548] In some aspects, the communication schedule may include scheduling information for at least one acknowledgment for distributed MIMO communication. In some aspects, the scheduling information may include: at least one acknowledgment resource for each of a plurality of second wireless nodes, at least one acknowledgment resource for all of the plurality of second wireless nodes, at least one starting stream index for each of the plurality of second wireless nodes, at least one stream number for each of the plurality of second wireless nodes, at least one time slot for each of the plurality of second wireless nodes, at least one subband for each of the plurality of second wireless nodes, at least one modulation and coding scheme (MCS) for each of the plurality of second wireless nodes, or any combination thereof.

[0549] At box 5308, the device outputs the communication schedule for transmission.

[0550] In some aspects, process 5300 may include the apparatus generating at least one schedule frame comprising a communication schedule. In some aspects, outputting the communication schedule may include outputting the at least one schedule frame for transmission. In some aspects, the at least one schedule frame may be output for transmission before, in combination with, or after the at least one trigger frame. In some aspects, the at least one schedule frame may include an aggregate schedule frame for all first wireless nodes in the plurality of first wireless nodes, the aggregate schedule frame output for transmission prior to distributed MIMO communication. In some aspects, the at least one schedule frame may be intended to trigger the plurality of second wireless nodes to initiate distributed MIMO communication. In some aspects, the at least one schedule frame may include an indication informing the plurality of first wireless nodes to skip transmitting the trigger frame. In some aspects, the at least one schedule frame may include a plurality of frames for a plurality of distributed MIMO transmissions, with a particular one of the frames preceding a corresponding one of the plurality of distributed MIMO transmissions. In some aspects, the plurality of frames may include a trigger frame. In some aspects, process 5300 may include the apparatus soliciting acknowledgments for the plurality of distributed MIMO transmissions. In some aspects, the at least one schedule frame may include trigger and schedule frames for all first wireless nodes in the plurality of first wireless nodes. In some aspects, the at least one scheduling frame may be configured to trigger a plurality of first wireless nodes to initiate transmission of at least one trigger frame. In some aspects, the at least one trigger frame may be configured to trigger distributed MIMO transmissions for all first wireless nodes in the plurality of first wireless nodes. In some aspects, the at least one trigger frame may be configured to trigger at least one second wireless node in the plurality of second wireless nodes to initiate distributed MIMO communication.

[0551] In some aspects, process 5300 may include the apparatus generating a trigger frame comprising a communication schedule. In some aspects, outputting the communication schedule may include outputting the trigger frame for transmission prior to the distributed MIMO communication.

[0552] In some aspects, process 5300 may include the apparatus obtaining second wireless node information. In some aspects, generating the communication schedule may be based on the second wireless node information. In some aspects, the second wireless node information may include: an identifier per basic service set (BSS) of any second wireless node from the plurality of second wireless nodes that is a candidate for distributed multiple-input multiple-output (MIMO) data reception within the cluster, a second wireless node identifier for any second wireless node from the plurality of second wireless nodes for which data is present, capability information for distributed MIMO reception by each second wireless node from the plurality of second wireless nodes, at least one resource for distributed MIMO communication to each second wireless node from the plurality of second wireless nodes, at least one identifier of at least one first wireless node from the plurality of first wireless nodes that is a candidate for performing a blanking operation for at least one second wireless node from the plurality of second wireless nodes, at least one scheduling priority metric for each second wireless node from the plurality of second wireless nodes, received signal strength indication (RSSI) difference tolerance information for each second wireless node from the plurality of second wireless nodes, or any combination thereof. In some aspects, for each second wireless node in the plurality of second wireless nodes, the RSSI difference tolerance information may include, for each second wireless node in the plurality of second wireless nodes, a maximum tolerable RSSI at the serving first wireless node due to at least one transmission by the second wireless node, an RSSI at each first wireless node due to at least one transmission by the second wireless node, or any combination thereof. In some aspects, the second wireless node information may include acknowledgment information for at least one acknowledgment for distributed MIMO data communication. In some aspects, for each second wireless node in the plurality of second wireless nodes, the acknowledgment information may include: at least one required acknowledgment resource, acknowledgment transmission capability information, at least one starting stream index, at least one stream number, at least one time slot, at least one subband, at least one modulation and coding scheme (MCS), or any combination thereof. In some aspects, the second wireless node information may include at least one acknowledgment resource for all second wireless nodes in the plurality of second wireless nodes. In some aspects, process 5300 may include the apparatus outputting at least one query for transmission. In some aspects, the at least one query may solicit second wireless node information from the plurality of first wireless nodes. In some aspects, the at least one query indicates at least one resource to be used per response, and the at least one resource may include at least one subband, at least one spatial stream index range, at least one time slot, or any combination thereof. In some aspects, process 5300 may include the device outputting at least one query for transmission. In some aspects, the at least one query may solicit second wireless node information from a plurality of second wireless nodes. In some aspects, obtaining the second wireless node information may include obtaining autonomous advertisements including the second wireless node information from a plurality of first wireless nodes. In some aspects, obtaining the autonomous advertisements may include collecting information during a designated advertisement period.In some aspects, obtaining the second wireless node information may include obtaining an autonomous advertisement including the second wireless node information from a plurality of second wireless nodes.

[0553] Figure 54 An example process 5400 for communication according to some aspects of the present disclosure is illustrated. The process 5400 may be performed on a processing system (e.g., Figure 49 The processing circuit may be located in an AP, a STA, or some other suitable device. Of course, in various aspects within the scope of the present disclosure, the process 5400 may be implemented by any suitable device capable of supporting communication-related operations.

[0554] At box 5402, an apparatus (e.g., an AP or some other node) obtains a communication schedule, wherein the communication schedule identifies a plurality of first wireless nodes and a second wireless node scheduled for distributed multiple-input multiple-output (MIMO) communication, wherein the plurality of first wireless nodes are members of a first wireless node cluster.

[0555] At block 5404, the apparatus generates information for distributed MIMO communication based on the communication schedule.

[0556] At block 5406, the device outputs the information (eg, for transmission to stations in the cluster).

[0557] In some aspects, process 5400 may include the apparatus outputting the second wireless node information for transmission. In some aspects, the second wireless node information may be used to generate a communication schedule. In some aspects, the second wireless node information may be output for transmission via: at least one physical (PHY) layer preamble, at least one high efficiency (HE) control field of a medium access control (MAC) header, at least one information element, or any combination thereof. In some aspects, process 5400 may include the apparatus obtaining at least one query. In some aspects, the at least one query may request the second wireless node information. In some aspects, the second wireless node information may be output after obtaining the at least one query.

[0558] Figure 55 Illustrated is an example process 5500 for communicating according to some aspects of the present disclosure. The process 5500 can be performed on a processing system (e.g., Figure 49 The processing circuit may be located in an AP, a STA, or some other suitable device. Of course, in various aspects within the scope of the present disclosure, process 5500 may be implemented by any suitable device capable of supporting communication-related operations.

[0559] At block 5502, an apparatus (e.g., an AP or some other node) obtains a communication schedule that identifies a plurality of first wireless nodes in a cluster of wireless nodes for collectively serving a plurality of second wireless nodes via distributed multiple-input multiple-output (MIMO) communication. In some aspects, the communication schedule may specify that a first second wireless node in the plurality of second wireless nodes communicate with a first first wireless node in the plurality of first wireless nodes during a particular time slot, and a second second wireless node in the plurality of second wireless nodes communicate with a second first wireless node in the plurality of first wireless nodes during a particular time slot.

[0560] At block 5504, the apparatus generates a frame to trigger distributed MIMO communication (e.g., uplink communication) by the plurality of second wireless nodes, wherein generation of the frame is based on a communication schedule. In some aspects, the frame may include a trigger frame including the communication schedule. In some aspects, the trigger frame may be scheduled for transmission prior to the distributed MIMO communication.

[0561] At block 5506, the apparatus outputs the frame (eg, for transmission to at least one access point in the cluster).

[0562] In some aspects, the process 5500 may include the apparatus determining, from the communication schedule, scheduling information for each second wireless node in a basic service set of a first wireless node in the plurality of first wireless nodes. In some aspects, the process 5500 may include the apparatus outputting the scheduling information for transmission on resources that are orthogonal to any resources used by any other first wireless node in the plurality of first wireless nodes for communication of other scheduling information.

[0563] In some aspects, the process 5500 may include the apparatus determining, from the communication schedule, scheduling information for each second wireless node in a basic service set of a first wireless node in the plurality of first wireless nodes. In some aspects, the process 5500 may include the apparatus outputting the scheduling information for transmission on the same resources used for communication of other scheduling information with any other first wireless node in the plurality of first wireless nodes.

[0564] In some aspects, process 5500 may include the device outputting the preamble for transmission on resources used by at least another first wireless node of the plurality of first wireless nodes for communication of the preamble.

[0565] In some aspects, process 5500 may include the device outputting the preamble for transmission on resources that are orthogonal to any resources used by at least another first wireless node of the plurality of first wireless nodes for communication of another preamble.

[0566] In some aspects, process 5500 may include the apparatus outputting second wireless node information for transmission, wherein the second wireless node information may be used to generate a communication schedule. In some aspects, the second wireless node information may be output for transmission via: at least one physical (PHY) layer preamble, at least one high efficiency (HE) control field of a medium access control (MAC) header, at least one information element, or any combination thereof. In some aspects, process 5500 may include the apparatus obtaining at least one query. In some aspects, the at least one query requests the second wireless node information. In some aspects, the second wireless node information may be output after the at least one query is obtained.

[0567] In some aspects, process 5500 may include the apparatus determining, from a communication schedule, scheduling information for each second wireless node in a basic service set of a first wireless node in the plurality of first wireless nodes among the plurality of second wireless nodes. In some aspects, generating a frame may include generating at least one trigger frame based on the scheduling information. In some aspects, outputting the frame may include outputting the at least one trigger frame for transmission to each second wireless node in a basic service set of a first wireless node in the plurality of first wireless nodes. In some aspects, the at least one trigger frame may include a plurality of trigger frames for a plurality of distributed MIMO transmissions. In some aspects, for a particular one of the trigger frames, the particular trigger frame precedes a corresponding one of the plurality of distributed MIMO transmissions. In some aspects, the at least one trigger frame may include at least one acknowledgment of the distributed MIMO transmission. In some aspects, the at least one trigger frame may include trigger and schedule frames for all first wireless nodes in the plurality of first wireless nodes. In some aspects, the trigger and schedule frames may be scheduled for transmission prior to the distributed MIMO communication.

[0568] In some aspects, process 5500 may include an apparatus determining scheduling information for all second wireless nodes in the plurality of second wireless nodes based on the communication schedule.In some aspects, the frame may include a trigger frame including scheduling information for all second wireless nodes in the plurality of second wireless nodes.

[0569] Figure 56 An example process 5600 for communication according to some aspects of the present disclosure is illustrated. The process 5600 may be performed on a processing system (e.g., Figure 49 The processing circuit may be located in an AP, a STA, or some other suitable device. Of course, in various aspects within the scope of the present disclosure, process 5600 may be implemented by any suitable device capable of supporting communication-related operations.

[0570] At block 5602, an apparatus (e.g., an AP or some other node) obtains a communication schedule, wherein the communication schedule identifies a plurality of first wireless nodes for joint communication over multiple basic service sets (multi-BSSs), wherein the plurality of first wireless nodes are members of a first cluster of wireless nodes. In some aspects, the communication schedule is sent by a first wireless node among the plurality of first wireless nodes prior to the joint transmission. In some aspects, the multi-BSS joint communication may be multi-BSS coordinated beamforming communication, joint MIMO communication, or orthogonal frequency division multiple access (OFDMA) communication.

[0571] At block 5604, the apparatus generates a frame based on the communication schedule.

[0572] At block 5606, the device outputs the frame (eg, for transmission to at least one station in the cluster).

[0573] In some aspects, a physical layer preamble of a frame may include a non-scheduling-related preamble portion and a scheduling-related preamble portion. In some aspects, the non-scheduling-related preamble portion has the same content for all first wireless nodes in the plurality of first wireless nodes and is for transmission by all first wireless nodes in the plurality of first wireless nodes on the same resources. In some aspects, the same content includes resource allocation information for the scheduling-related preamble portion for each first wireless node in the plurality of first wireless nodes. In some aspects, the scheduling-related preamble portion has the same content for each first wireless node in the plurality of first wireless nodes and is for transmission by all first wireless nodes in the plurality of first wireless nodes on the same resources. In some aspects, the same content includes downlink scheduling information for all scheduled second wireless nodes associated with the plurality of first wireless nodes. In some aspects, the scheduling-related preamble portion has different content for each first wireless node in the plurality of first wireless nodes and is for transmission by different first wireless nodes in the plurality of first wireless nodes on orthogonal resources. In some aspects, the different content for each of the plurality of first wireless nodes includes downlink scheduling information for all scheduled second wireless nodes associated with the plurality of first wireless nodes.

[0574] Example device

[0575] The components described herein may be implemented in various ways. Figure 57 , apparatus 5700 is represented as a series of interrelated functional blocks that represent functions implemented by, for example, one or more integrated circuits (e.g., ASICs), or in some other manner as taught herein. As discussed herein, an integrated circuit may include a processor, software, other components, or some combination thereof.

[0576] Apparatus 5700 includes one or more components (modules) that can perform one or more functions described herein with respect to the various figures. For example, circuitry 5702 (e.g., an ASIC) for obtaining (e.g., an apparatus for obtaining) may correspond to, for example, an interface (e.g., a bus interface, a transmit / receive interface), a communication device, a transceiver, a transmitter, or some other similar component discussed herein. Circuitry 5704 (e.g., an ASIC) for determining (e.g., an apparatus for determining) may correspond to, for example, a processing system discussed herein. Circuitry 5706 (e.g., an ASIC) for generating (e.g., an apparatus for generating) may correspond to, for example, a processing system discussed herein. Circuitry 5708 (e.g., an ASIC) for outputting (e.g., an apparatus for outputting) may correspond to, for example, an interface (e.g., a bus interface, a transmit / receive interface), a communication device, a transceiver, a receiver, or some other similar component discussed herein. Circuitry 5710 (e.g., an ASIC) for identifying (e.g., an apparatus for identifying) may correspond to, for example, a processing system discussed herein. A circuit 5712 (eg, an ASIC) for soliciting (eg, means for soliciting) may correspond to, for example, a processing system as discussed herein.

[0577] Figure 57 Two or more modules in the can communicate with each other or some other components via a signaling bus 5714. In various implementations, Figure 46 Processing system 4604 and / or Figure 49 The processing system 4904 may include Figure 57 One or more circuits in the circuit.

[0578] As mentioned above, in some aspects, these modules can be implemented via appropriate processor components. In some aspects, these processor components can be implemented at least in part using structures as taught herein. In some aspects, the processor can be configured to implement part or all of the functionality of one or more of these modules. Therefore, the functionality of different modules can be implemented, for example, as different subsets of integrated circuits, different subsets of software module sets, or a combination thereof. Similarly, it should be appreciated that a given subset (e.g., of an integrated circuit and / or software module set) can provide at least a portion of the functionality of more than one module. In some aspects, one or more of any components represented by dashed boxes herein can be optional.

[0579] As mentioned above, the apparatus 5700, in some implementations, includes or takes the form of one or more integrated circuits. For example, in some aspects, a single integrated circuit implements the functionality of one or more of the illustrated components, while in other aspects, more than one integrated circuit implements the functionality of one or more of the illustrated components. As a specific example, the apparatus 5700 can be a single device (e.g., where components 5702-5712 constitute different portions of an ASIC). As another specific example, the apparatus 5700 can be several devices (e.g., where components 5702 and 5708 constitute one ASIC and components 5704, 5706, 5710, and 5712 constitute another ASIC).

[0580] in addition, Figure 57 The components and functions shown and other components and functions described herein may be implemented using any suitable means. Such devices may be implemented at least in part using corresponding structures as taught herein. For example, the above combined Figure 57 The components described in the "AISC for..." components correspond to similarly designated "means for..." functionality. Thus, in some implementations, one or more of such means are implemented using one or more of processor components, integrated circuits, or other suitable structures as taught herein.

[0581] The various operations of the methods described herein may be performed by any suitable means capable of performing the corresponding functions. These means may include various hardware and / or software components and / or modules, including but not limited to circuits, application specific integrated circuits (ASICs), or processors. Generally, where there are operations illustrated in the figures, these operations may have corresponding paired means-plus-function components with similar functionality and / or numbering. For example, the blocks of processes 5000-5600 illustrated herein may correspond, at least in some aspects, to Figure 57 For example, the means for obtaining may be circuit 5702 for obtaining, the means for determining may be circuit 5704 for determining, the means for generating may be circuit 5706 for generating, the means for outputting may be circuit 5708 for outputting, the means for identifying may be circuit 5710 for identifying, and the means for soliciting may be circuit 5712 for soliciting.

[0582] Reference Figure 58 , the programming stored by the memory 5800 (eg, storage medium, memory device, etc.) when executed by the processing system (eg, Figure 49When executed by the processing system 4904, the programming may cause the processing system 4904 to perform one or more of the various functions and / or processing operations described herein. For example, the programming, when executed by the processing system 4904, may cause the processing system 4904 to perform various functions, steps, and / or processes described herein in various implementations. Figure 58 As shown, memory 5800 may include one or more of code for obtaining 5802, code for determining 5804, code for generating 5806, code for outputting 5808, code for identifying 5810, and code for soliciting 5812. In some aspects, one or more of code for obtaining 5802, code for determining 5804, code for generating 5806, code for outputting 5808, code for identifying 5810, or code for soliciting 5812 may be executed or otherwise used to provide the functionality of circuitry for obtaining 5702, circuitry for determining 5704, circuitry for generating 5706, circuitry for outputting 5708, circuitry for identifying 5710, or circuitry for soliciting 5712 described herein. In some aspects, Figure 58 The memory 5800 may correspond to Figure 49 Memory 4906.

[0583] Additional aspects

[0584] The examples set forth herein are provided to illustrate certain concepts of the present disclosure. Those of ordinary skill in the art will appreciate that these examples are merely illustrative in nature, and other examples may fall within the scope of the present disclosure and the appended claims. Based on the teachings herein, those skilled in the art will appreciate that the aspects disclosed herein may be implemented independently of any other aspects and that two or more of these aspects may be combined in various ways. For example, any number of aspects set forth herein may be used to implement a device or practice a method. Additionally, other structures, functions, or structures and functions that supplement or differ from one or more aspects set forth herein may be used to implement such a device or practice such a method.

[0585] As will be readily appreciated by those skilled in the art, the various aspects described throughout this disclosure can be extended to any suitable telecommunication system, network architecture, and communication standard. By way of example, the various aspects can be applicable to wide area networks, peer-to-peer networks, local area networks, other suitable systems, or any combination thereof, including those described by yet-to-be-defined standards.

[0586] Many aspects are described in the form of a sequence of actions to be performed by, for example, elements of a computing device. It will be appreciated that the various actions described herein can be performed by specific circuits, such as a central processing unit (CPU), a graphics processing unit (GPU), a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA), or various other types of general-purpose or special-purpose processors or circuits, by program instructions that can be executed by one or more processors, or by a combination of the two. Additionally, these action sequences described herein may be considered to be fully embodied in any form of computer-readable storage medium having a corresponding set of computer-executable instructions (e.g., a computer-readable medium storing computer executable code, including code for performing the functionality described herein) that, upon execution, causes the associated processor to perform the functionality described herein. Thus, various aspects of the present disclosure may be implemented in several different forms, all of which are contemplated to fall within the scope of the claimed subject matter. In addition, for each aspect described herein, the corresponding form of any such aspect may be described herein as, for example, "logic configured to perform the described actions."

[0587] In some aspects, a device or any component of a device may be configured (or operable or adapted) to provide functionality as taught herein. This may be achieved, for example, by manufacturing (e.g., fabricating) the device or component so that it will provide the functionality; by programming the device or component so that it will provide the functionality; or by using some other suitable implementation technique. As an example, an integrated circuit may be fabricated to provide the necessary functionality. As another example, an integrated circuit may be fabricated to support the necessary functionality and then configured (e.g., via programming) to provide the necessary functionality. As yet another example, a processor circuit may execute code to provide the necessary functionality.

[0588] Those skilled in the art will appreciate that information and signals may be represented using any of a variety of different technologies and techniques. For example, data, instructions, commands, information, signals, bits, symbols, and chips that may be referred to throughout the above description may be represented by voltages, currents, electromagnetic waves, magnetic fields or particles, optical fields or particles, or any combination thereof.

[0589] In addition, those skilled in the art will appreciate that the various illustrative logic blocks, modules, circuits, and algorithmic steps described in conjunction with the aspects disclosed herein can be implemented as electronic hardware, computer software, or a combination of both. To clearly illustrate this interchangeability of hardware and software, various illustrative components, blocks, modules, circuits, and steps are generally described above in terms of their functionality. Whether such functionality is implemented as hardware or software depends on the specific application and the design constraints imposed on the overall system. A skilled person may implement the described functionality in different ways for each specific application, but such implementation decisions should not be interpreted as causing a departure from the scope of this disclosure.

[0590] One or more of the components, steps, features and / or functions described above can be rearranged and / or combined into a single component, step, feature or function, or can be implemented in several components, steps or functions. Additional elements, components, steps and / or functions can also be added without departing from the novel features disclosed herein. The apparatus, equipment and / or components described above can be configured to perform one or more methods, features, or steps described herein. The novel algorithms described herein can also be efficiently implemented in software and / or embedded in hardware.

[0591] It should be understood that the specific order or hierarchy of steps in the disclosed methods is illustrative of example processes. Based on design preferences, it should be understood that the specific order or hierarchy of steps in these methods may be rearranged. The accompanying method claims present elements of the various steps in a sample order and are not meant to be limited to the specific order or hierarchy presented unless specifically recited herein.

[0592] The methods, sequences, or algorithms described in conjunction with the aspects disclosed herein may be embodied directly in hardware, in a software module executed by a processor, or in a combination of the two. The software module may reside in RAM memory, flash memory, ROM memory, EPROM memory, EEPROM memory, registers, a hard disk, a removable disk, a CD-ROM, or any other form of storage medium known in the art. Examples of storage media are coupled to a processor so that the processor can read and write information from / to the storage medium. Alternatively, the storage medium may be integral to the processor.

[0593] The word "exemplary" is used herein to mean "serving as an example, instance, or illustration." Any aspect described herein as "exemplary" is not necessarily to be construed as preferred or advantageous over other aspects. Likewise, the term "aspects" does not require that all aspects include the discussed feature, advantage, or mode of operation.

[0594] The terms used herein are only for the purpose of describing specific aspects, and are not intended to limit these aspects. As used herein, the singular forms "one", "some" and "the" are intended to also include plural forms, unless the context clearly indicates otherwise. It will also be understood that the terms "include", "have", "comprise" and / or "contain" specify the existence of stated features, integers, steps, operations, elements, and / or components when used in this article, but do not exclude the existence or addition of one or more other features, integers, steps, operations, elements, components and / or their groups. In addition, it is to be understood that the word "or" has the same meaning as the Boolean operator "OR (or)", that is, it covers the possibility of "either" and "both" and is not limited to "exclusive or" ("XOR"), unless otherwise clearly stated. It will also be understood that the symbol " / " between two adjacent words has the same meaning as "or", unless otherwise clearly stated. In addition, unless otherwise clearly stated, phrases such as "connected to", "coupled to" or "in communication" are not limited to direct connection.

[0595] Any reference to an element such as "first", "second" or the like is used herein and does not generally limit the quantity or order of those elements. Specifically, these references can be used as a convenient method to distinguish two or more elements or element instances in this article. Therefore, the reference to the first element and the second element does not mean that only two elements can be adopted here or that the first element must be located before the second element in some way. Similarly, unless otherwise stated, an element set may include one or more elements. In addition, the term "at least one of a, b, or c" or "one or more of a, b, or c" used in the specification or claims means "a or b or c or any combination of these elements". For example, this term can include a, or b, or c, or a and b, or a and c, or a and b and c, or 2a, or 2b, or 2c, or 2a and b, etc.

[0596] As used herein, the term "determining" encompasses a wide variety of actions. For example, "determining" may include calculating, computing, processing, deriving, investigating, searching (e.g., searching in a table, database, or other data structure), ascertaining, and the like. Furthermore, "determining" may include receiving (e.g., receiving information), accessing (e.g., accessing data in a memory), and the like. Similarly, "determining" may also include resolving, selecting, choosing, establishing, and the like.

[0597] While the foregoing disclosure shows illustrative aspects, it should be noted that various changes and modifications may be made therein without departing from the scope of the appended claims. The functions, steps, and / or actions of the method claims according to the aspects described herein do not have to be performed in any particular order unless expressly stated otherwise. Additionally, although elements may be described or claimed in the singular, the plural is also contemplated unless limitation to the singular is expressly stated.

Claims

1. A device for communication, comprising: A processing system configured to: identifying a plurality of access points in the cluster of wireless nodes for collectively serving a plurality of stations via distributed multiple-input multiple-output (MIMO) communications, and generating a communication schedule that specifies that a first station of the plurality of stations transmit to a first access point of the plurality of access points during a first time slot and a second station of the plurality of stations transmit to a second access point of the plurality of access points during the first time slot, wherein the communication schedule further specifies whether the first access point is to perform a beamforming nulling operation during the first time slot to null interference from the second station; as well as An interface is configured to output the communication schedule for transmission.

2. The apparatus of claim 1, wherein the distributed MIMO communication comprises coordinated beamforming communication or uplink joint MIMO communication.

3. The device according to claim 1, wherein The processing system is further configured to: determining that the first station is in a first basic service set of the first access point and has first uplink data to send; and It is determined that the second station is in a second basic service set of the second access point and has second uplink data to send.

4. The device according to claim 3, wherein The processing system is further configured to: It is determined that the second station is not in a basic serving set of the first access point and will be nulled by the first access point.

5. The apparatus of claim 1, wherein the communication schedule further comprises scheduling information for the plurality of access points to trigger distributed MIMO transmissions by the plurality of stations during the first time slot.

6. The apparatus of claim 5, wherein the scheduling information comprises: Identifiers of the plurality of access points, resource allocations for the plurality of access points to trigger the distributed MIMO transmission, at least one corresponding starting stream index for each of the plurality of access points, at least one corresponding number of streams for each of the plurality of access points, at least one corresponding time slot for each of the plurality of access points, at least one corresponding subband for each of the plurality of access points, at least one corresponding modulation and coding scheme (MCS) for each of the plurality of access points, a duration of at least one frame for triggering the distributed MIMO transmission, at least one bandwidth of at least one frame for triggering the distributed MIMO transmission, or any combination thereof.

7. The device according to claim 1, wherein The communication schedule includes: station identifiers of the plurality of stations, distributed MIMO communication resource allocations for the plurality of stations, at least one identifier of at least one access point of the plurality of access points scheduled to perform a blanking operation for at least one station of the plurality of stations, at least one received signal strength indication (RSSI) at each access point of the plurality of access points, a duration of the distributed MIMO communication, at least one bandwidth for the distributed MIMO communication, or any combination thereof.

8. The device according to claim 1, wherein The communication schedule further includes scheduling information of at least one downlink (DL) acknowledgement for the distributed MIMO communication.

9. The device according to claim 8, wherein The scheduling information includes: at least one DL acknowledgment resource for each of the plurality of stations, at least one DL acknowledgment resource for all of the plurality of stations, at least one starting stream index for each of the plurality of stations, at least one number of streams for each of the plurality of stations, at least one time slot for each of the plurality of stations, at least one subband for each of the plurality of stations, at least one modulation and coding scheme (MCS) for each of the plurality of stations, or any combination thereof.

10. The device of claim 1, wherein: The processing system is further configured to: Obtain station information; and The communication schedule is generated based on the station information.

11. The device according to claim 10, wherein For each of the plurality of stations, the station information includes: a station identifier, at least one distributed MIMO communication capability, at least one required UL data resource, at least one identifier of at least one access point among the plurality of access points on which a blanking operation needs to be performed, at least one scheduling priority metric, received signal strength RSSI difference information, or any combination thereof.

12. The device according to claim 11, wherein The nulling operation includes generating at least one signal to null interference from at least one station of the plurality of stations.

13. The device according to claim 11, wherein For the first station, the RSSI difference information includes: a maximum tolerable RSSI at the first access point due to uplink transmissions by the first station, at least one RSSI at each of the plurality of access points due to at least one uplink transmission by the first station, or any combination thereof.

14. The apparatus of claim 10, wherein: The station information is used for at least one downlink (DL) acknowledgement of the distributed MIMO communication.

15. The apparatus of claim 14, wherein: For each of the plurality of stations, the station information includes: at least one required DL acknowledgment resource, at least one starting stream index, at least one number of streams, at least one time slot, at least one subband, at least one modulation and coding scheme MCS, or any combination thereof.

16. The apparatus of claim 14, wherein: The station information includes at least one DL acknowledgment resource for all stations of the plurality of stations.

17. The apparatus of claim 1, wherein: The communication schedule further specifies whether the second access point is to perform a second beamforming nulling operation during the first time slot to null interference from the first station.

18. A communication method, comprising: identifying a plurality of access points in the cluster of wireless nodes for collectively serving a plurality of stations via distributed multiple-input multiple-output (MIMO) communications; generating a communication schedule that specifies that a first station of the plurality of stations transmit to a first access point of the plurality of access points during a first time slot and a second station of the plurality of stations transmit to a second access point of the plurality of access points during the first time slot, wherein the communication schedule further specifies whether the first access point is to perform a beamforming nulling operation during the first time slot to null interference from the second station; as well as The communication schedule is output for transmission.

19. The method of claim 18, wherein identifying the plurality of access points comprises: Determining whether the first access point has sufficient dimensionality to serve at least one station of the plurality of stations that is in a basic serving set of the first access point and blanking any stations of the plurality of stations that are not in a basic serving set of the first access point and that need to be blanked for the distributed MIMO communication.

20. The method of claim 18, wherein: Outputting the communication schedule for transmission includes: The communication schedule is output for transmission via at least one schedule frame.

21. The method of claim 20, wherein: The at least one scheduling frame comprises scheduling frames for all access points of the plurality of access points; and The at least one scheduled frame is scheduled for transmission prior to the distributed MIMO communication.

22. The method of claim 20, wherein the scheduling frame triggers the plurality of stations to begin the distributed MIMO communication.

23. The method of claim 22, wherein the schedule frame includes an indication informing the plurality of access points to skip a frame that triggers the plurality of stations to begin the distributed MIMO communication.

24. The method of claim 18, further comprising: Get station information; Wherein generating the communication schedule is based on the station information.

25. The method of claim 24, further comprising: At least one query is output for transmission, wherein the at least one query solicits the station information from the plurality of access points.

26. The method of claim 25, wherein: The at least one query indicates at least one resource to be used for at least one response to the at least one query; and The at least one resource includes at least one subband, at least one spatial stream, at least one time slot, or any combination thereof.

27. The method of claim 24, further comprising: At least one query is output for transmission, wherein the at least one query solicits the station information from the plurality of stations.

28. The method of claim 24, wherein: Obtaining the station information includes: Autonomous advertisements of the station information are obtained from the plurality of access points.

29. The method of claim 24, wherein: Obtaining the station information includes: Obtaining autonomous advertising of the station information from the plurality of stations.

30. A first access point, comprising: A processing system configured to: identifying a plurality of access points in a cluster of wireless nodes for collectively serving a plurality of stations via distributed multiple-input multiple-output (MIMO) communications, wherein the plurality of access points includes the first access point, and generating a communication schedule that specifies that a first station of the plurality of stations transmit to the first access point during a first time slot and a second station of the plurality of stations transmit to a second access point of the plurality of access points during the first time slot, wherein the communication schedule further specifies whether the first access point is to perform a beamforming nulling operation during the first time slot to null interference from the second station; as well as A transceiver is configured to transmit the communication schedule.

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