Access point and communication device

Abstract

An access point configured to communicate with a first communication device and a second communication device, the access point including circuitry configured to: - send a CBF response to a second communication device configured to communicate with a third communication device in response to a coordinated beamforming (CBF) request; - receive a feedback response from either the second or third communication device, the feedback response including post-coded information of the third communication device for communicating with the second communication device and / or channel information of the channel between the access point and the third communication device; - determine second guidance information based on the feedback response; and - communicate with the first communication device using the second guidance information and coordinate communication between the second and third communication devices.

Description

Technical Field

[0001] This disclosure relates to access points and communication devices, specifically access points and communication devices for coordinating beamforming. Furthermore, the invention relates to corresponding communication methods. Background Technology

[0002] Due to the need for high-definition video transmission from users' mobile locations at any given moment, future wireless extended reality (XR) applications demand low latency and extremely high throughput. While WLANs employ carrier sense mechanisms as part of channel access, this mechanism does not adequately guarantee that each station (STA; generally referred to as the "communication device" in this document) can transmit data whenever data traffic arrives at the STA. Furthermore, communication interference exists between access points (APs) and STAs, such as in cases of low-latency communication between two STAs on direct links (e.g., point-to-point (P2P) links).

[0003] The “Background Art” description provided herein is for the purpose of presenting the general context of this disclosure. The work of the currently named inventors, within the scope described in this Background Art section and in aspects that may not be described as prior art at the time of application, is neither explicitly nor implicitly acknowledged as prior art relative to this disclosure. Summary of the Invention

[0004] One objective is to ensure low-latency and / or extremely high-throughput communication between two communication devices, and to avoid or at least reduce interference in such communication that may occur during parallel communication between an access point and another communication device. Another objective is to provide a corresponding method and a corresponding computer program and a non-transitory computer-readable recording medium storing a computer program product for implementing the method.

[0005] According to one aspect, an access point configured to communicate with a first communication device and a second communication device is provided, the access point including circuitry configured to perform the following steps: - In response to a Coordinated Beamforming (CBF) request, a CBF response is sent to a second communication device configured to communicate with a third communication device; - Receive a feedback response from the second or third communication device, the feedback response including post-coded information used by the third communication device to communicate with the second communication device and / or channel information of the channel between the access point and the third communication device; - Determine the second guidance information based on the feedback response; and - Use the second guidance information to communicate with the first communication device, and coordinate the communication between the second and third communication devices.

[0006] According to another aspect, a second communication device is provided, configured to communicate with a third communication device and an access point, the second communication device including circuitry configured to perform the following steps: - Send a coordinated beamforming (CBF) request to the access point configured to communicate with the first and second communication devices. - In response to a CBF request, receive a CBF response from the access point; and - Send a feedback request to a third communication device, thereby requesting the third communication device to send a feedback response to the access point. The feedback response includes post-encoded information used by the third communication device to communicate with the second communication device and / or channel information of the channel between the access point and the third communication device.

[0007] According to another aspect, a third communication device is provided, configured to communicate with a second communication device, the third communication device including circuitry configured to perform the following steps: - Receive training packets from an access point configured to communicate with a first communication device and a second communication device, and / or receive a feedback request from the second communication device to send a feedback response to the access point, the feedback response including post-coded information for communication between the third communication device and the second communication device; and - In response to feedback requests and / or training groups, send feedback responses to the access point.

[0008] According to another aspect, a corresponding method, a computer program including program units, and a non-transitory computer-readable recording medium are provided, the program units being used to cause the computer to perform the steps of the method disclosed herein when the computer program is executed on a computer, the non-transitory computer-readable recording medium storing a computer program product therein, the computer program product causing the method disclosed herein to be executed when executed by a processor.

[0009] The embodiments are defined in the dependent claims. It should be understood that the disclosed method, the disclosed computer program, and the disclosed computer-readable recording medium have other embodiments similar to and / or identical to the claimed apparatus and as defined in the dependent claims and / or disclosed herein.

[0010] One aspect of this disclosure is the use of feedback responses sent from participants in low-latency and / or extremely high-throughput communication (referred to herein as the "third communication device") to an access point. The feedback responses include, for example, post-coding (or MIMO (Multiple-Input Multiple-Output) equalizer) information in the form of a post-coding matrix, which enables the access point to determine, for example, guidance information in the form of a guidance matrix, for communication with the access point's communication device (referred to herein as the "first communication device"), thereby avoiding or at least reducing interference in communication between the participants in the low-latency and / or extremely high-throughput communication (the second and third communication devices).

[0011] The foregoing paragraphs have been provided by way of general description and are not intended to limit the scope of the appended claims. The described embodiments and other advantages will be best understood from the following detailed description, taken in conjunction with the accompanying drawings. Attached Figure Description

[0012] A more comprehensive understanding of this disclosure and its many accompanying advantages will become better understood, and thus readily available, through the following detailed description taken in conjunction with the accompanying drawings: Figure 1 A diagram illustrating an exemplary system to which this disclosure can be applied is shown.

[0013] Figure 2 It shows Figure 1 The diagram shows an exemplary system, indicating different channels.

[0014] Figure 3 The equation for the interference signal from the third communication device at the access point is shown.

[0015] Figure 4 The equation for the interference signal from the third communication device at the access point is shown, and its terminology is consistent with... Figure 3 The parts are different.

[0016] Figure 5 It shows Figure 1 The diagram shows an exemplary system, in which exemplary beams are indicated to illustrate embodiments of this disclosure.

[0017] Figure 6 A diagram illustrating an implementation of the communication scheme according to this disclosure is shown.

[0018] Figure 7 An example of frequency channel allocation for two links is shown.

[0019] Figure 8 A diagram illustrating another embodiment of the communication scheme according to this disclosure is shown.

[0020] Figure 9A diagram illustrating yet another embodiment of the communication scheme according to this disclosure is shown.

[0021] Figure 10 A flowchart illustrating the communication method of the access point is shown.

[0022] Figure 11 A flowchart of the communication method of the second communication device is shown.

[0023] Figure 12 A flowchart of the communication method of the third communication device is shown. Detailed Implementation

[0024] Referring now to the accompanying drawings, the same reference numerals consistently designate the same or corresponding parts in several views. Figure 1 A diagram illustrating an exemplary system to which this disclosure can be applied is shown. In this example, both high reliability and high data rate are achieved in an XR application between STA2 and STA3. All STAs (also commonly referred to as communication devices) belong to the same Basic Service Set (BSS). STA2 (e.g., a PC or console device; also referred to herein as “second communication device”) and STA3 (e.g., a head-mounted display; HMD; also referred to herein as “third communication device”) are connected to each other as a direct link (e.g., a point-to-point (P2P) link) using a Tunneled Direct Link Setup (TDLS) disclosed in the IEEE 802.11 standard. STA2 and STA3 can communicate with each other on a channel different from the primary channel of the BSS, but due to the high throughput requirements of XR applications on the P2P link, it is difficult to allocate wide bandwidth for the P2P link without overlapping with any other links. AP and STA1 (also referred to herein as “first communication device”) can communicate with each other via a separate link, which can be a non-P2P link. AP may be a source of interference on the STA2-STA3 link.

[0025] A potential solution is to utilize the AP's spatial domain to guide nulls to the HMD (i.e., mitigate interference) when the AP is transmitting data to STA1 and STA2 is simultaneously transmitting data to STA3; this is called Coordinated Beamforming (CBF). Typically, the AP derives a steering matrix (more generally, steering information) orthogonal to the channel between the AP and STA3, and uses this steering matrix to mitigate interference to STA3. Although CBF requires Channel State Information (CSI) and may require the transmitter (e.g., Figure 1While the AP and STA2 in the signaling circuit synchronize with each other for better performance, it essentially allows transmitters to simultaneously transmit to different destinations on partially or fully overlapping channels, mitigating interference at unintended destinations. CBF utilizes concurrent probing between transmitters to achieve better performance. Although there are several different terms indicating CBF (such as coordinated nulling, joint processing, etc.), CBF in this paper should be understood as a beamforming scheme in which several transmitters are directed to nulls at unintended receivers for simultaneous transmission, resulting in less interference at the intended receiver.

[0026] Typically, the term "Basic Service Set (BSS)" refers to the set of STAs that have been successfully synchronized. The term "beamforming receiver" refers to an STA that receives data units (e.g., Physical Layer (PHY) Protocol Data Units (PPDUs)) transmitted using a beamforming steering matrix. The term "beamforming transmitter" refers to an STA that transmits data units (e.g., PPDCUs) using a beamforming steering matrix. The term "beamforming steering matrix" refers to a matrix determined using knowledge of the channel between the transmitter and the intended receiver, mapping the spatiotemporal flow to the transmit antenna with the goal of improving the signal power or signal-to-noise ratio (SNR) at the intended receiver.

[0027] In the following explanation, the following assumptions are made: The channel used for the communication link between AP and STA1 may partially overlap with the channel used for the P2P link between STA2 and STA3. ,in It is the number of spatial flows on the link between STA2 and STA3, and This refers to the number of receiving antennas for STA3.

[0028] If STA2 has the capability to perform interference suppression, or is assumed to perform interference suppression (in other words, to guide the AP sending signals toward STA1 into a null trap), then... again ,in It is the number of spatial flows on the link between AP and STA1, and This represents the number of transmit antennas for the AP. Equation This means that the AP does not have enough transmit antennas to transmit to STA1 while simultaneously receiving from STA2. The STA3-guided zero trap of a spatial flow. Another equation This means that STA3 does not have enough receiving antennas to receive signals from STA2, while suppressing signals transmitted to STA1. Interference from the AP of a spatial flow. One example that satisfies the above equation is... .

[0029] If STA2 does not have the ability to perform interference suppression, or if it is assumed that it does not perform interference suppression, then the above conditions can be ruled out. And should satisfy In this case, This is one example under this assumption.

[0030] In the above equation, and They usually satisfy respectively and .

[0031] As a typical example of the above discussion, we can assume that the AP-STA1 link uses one spatial flow (SS), the STA2-STA3 link uses one SS, the AP has two antennas, and STA3 has two antennas. The problem with CBF (Cross-Current Flow) might be that the AP requires three antennas in this case because one spatial degree of freedom (DoF) is allocated for transmitting to STA1, and the other two spatial DoFs are consumed to guide nulls towards STA3. Intuitively, in this case, "spatial DoF" is "the number of antennas of the AP." The problem with interference suppression (or Rx nulls) might be that STA3 requires three antennas in this case because one spatial DoF is used to receive the SS from STA2, and the other two spatial DoFs are consumed to guide nulls towards the AP. Intuitively, in this case, "spatial DoF" is "the number of antennas of STA3." There wouldn't be any problem if each device had more antennas, but in practice, a small number of antennas is usually set up or assumed.

[0032] More generally, under the assumptions mentioned above, AP can use at most One space DoF, but using regular CBF consumes Each spatial degree of freedom is used to guide STA3 towards a null trap. If If the AP cannot prevent interference with STA3 when both the AP and STA are transmitting simultaneously, then at least the interference needs to be reduced. To meet the conditions In order to meet the conditions To implement CBF, improvements to the BF algorithm and protocol are required. To this end, several implementation methods are proposed in this disclosure.

[0033] Figure 2 It shows Figure 1 The diagram shows an exemplary system, indicating different channels. h 1 indicates the channel (also known as the first channel) of the link from STA2 to STA3 (P2P link). h 2 represents the channel (also known as the second channel) of the link from AP to STA3 (interference link 1), and h3 indicates the channel (also known as the third channel) of the link from AP to STA1 (non-P2P link). Furthermore, it should be assumed that STA... k have One antenna and the AP has One antenna.

[0034] In normal operation, AP knows before guiding STA3 to the zero trap. h 2, but the post-coding matrix to be used for the P2P link at STA3 is unknown. P (More generally, post-encoded information), because the post-encoded matrix P Based on at least h 1. And the number of spatial flows on the P2P link, usually determined by STA2. In this case, the AP's steering matrix can be calculated. w AP This makes the guidance matrix (almost) the same as h 2. Orthogonal to ensure less interference at STA3. Equation (1) expresses the received signal as the first signal from STA2 at STA3. i Space Flow y i ,in This is an expected signal from STA2. It is spatial flow interference from STA2. It is an interference signal from AP targeting the i-th spatial stream from STA2, and w STA2 This is the STA2 steering matrix for P2P links. X ] (a,b) Indicator Matrix X The (a,b) components:

[0035] However, in practice, the number of antennas that can be implemented is limited, making it difficult to satisfy certain conditions. In certain circumstances, the above mechanisms will hardly work. It should be assumed that... h 2 is take Matrix, and h The rank of 2 is When AP attempts to guide STA3 to a zero trap, AP consumes... One spatial degree of freedom is used for zero traps, and AP can be allocated at most One spatial degree of freedom is used for transmission to the STA. In this case, the AP calculates... w AP , making w AP (Almost) with h2 orthogonal, such as Figure 3 As shown in the figure, this diagram illustrates the equation for the interference signal from the AP at STA3. If If so, the AP cannot allocate or compute any vectors for transmission to STA1.

[0036] If AP knows Ph 2, then even if it satisfies The AP may also lead to a zero trap towards STA3 while simultaneously sending data to STA1. In this case, according to this disclosure, the AP calculates... w AP , making w AP (Almost) with Ph 2. Orthogonal, not with as described above. h 2. Orthogonal. If Ph rank of 2 rank ( Ph 2) Less than Then AP only needs to consume rank ( Ph 2) Spatial degrees of freedom, and can be assigned or computed at most. One vector is used for transmission to STA1, while the AP transmits the data to the post-encoded matrix. P STA3 guide zero trap.

[0037] Typically, calculations are performed from the training field of each received signal from STA2. P It is not guaranteed that it will always be the same matrix, because... h 1 can be changed to some extent. Furthermore, P The size depends on the number of spatial streams on the P2P link. However, the AP can guide the STA3 into a null trap for a certain period of time if the following conditions are met: i) the channel h 1 and h 2 can be considered static during this duration, which means P It can also be considered static, and ii) the number of spatial streams on the P2P link is fixed during that duration.

[0038] As mentioned above, AP should know Ph 2 (in) Figure 4 The instructions are as follows X The figure shows the equation for the interference signal from the AP at STA3, with terms similar to... Figure 3 (Some parts are different). Furthermore... Ph 2 can be fed back to the AP. Below, Ph Any form of feedback is called a feedback response (which may also be called feedback information or kernel feedback).

[0039] The following describes an implementation of a communication scheme or protocol for sending feedback responses (kernel feedback). The communication link from AP to STA3 should be referred to as interference link 1, and the communication link from STA2 to STA1 should be referred to as interference link 2. It should be assumed that each device sometimes sends data to the destination on the interference link, and that signals on the interference link are not always considered interference. The feedback response for interference link 1 will be considered only below.

[0040] like Figure 2 As shown, each of STA1, STA2 (control console), and STA3 (HMD) is associated with an AP. STA2 and STA3 establish a P2P link between them with the support of the AP (e.g., based on TDLS). The capabilities of each device can be exchanged between devices by establishing associations, and may include the ability to provide feedback responses. The methods for establishing P2P links should not be discussed in more detail in this document.

[0041] Figure 5 It shows Figure 1 The diagram shows an exemplary system, in which exemplary beams are indicated to illustrate embodiments of this disclosure. Figure 6 A diagram illustrating an implementation of the communication scheme according to this disclosure is shown. Figure 5 Specific instructions were given. Figure 6 Some of the basic steps of the communication scheme shown are steps 100, 200, 300, and 400. Figure 5 and Figure 6 Part of the concept illustrated is that the AP uses knowledge of STA3's receive (Rx) beam (or post-coding matrix) to set its beam. Therefore, the AP may consume only one spatial DoF after knowing STA3's Rx beam. Since non-P2P links also require high data rates, STA2 and STA3 set their Tx / Rx beams before the AP.

[0042] The P2P link can remain active until the time specified in the P2P link settings, or until the AP receives an indication of P2P link termination from STA2 or STA3.

[0043] Initially (not shown), capability exchange can be performed. STA3 can send the following instructions to AP: · It is the minimum number of nulls required for STA3 to receive unexpected / interference signals simultaneously; and · It is the maximum number of nulls that the STA3 can receive when receiving signals simultaneously, for unexpected / interference signals.

[0044] This instruction can be sent as part of the capability during the association between AP and STA3.

[0045] In step 1, P2P link settings can be configured. For example... Figure 6 As shown, a P2P link is established between STA2 and STA3. Through the P2P link setup, AP, STA2, and STA3 negotiate which frequency channel is allocated to the P2P link and determine whether the frequency channel used for the P2P link fully or partially overlaps with the frequency channel used for the non-P2P link. STA2 can also establish a P2P link with STA1 in the same way, but the frequency channel between STA1 and STA2 should include frequency channels that overlap with both the non-P2P and P2P links. For example, if the BSS's primary channel P and secondary channel S1 are allocated for the non-P2P link, and secondary channels S1 to S3 are allocated for the P2P link between STA2 and STA3, then the channel frequency of the P2P link between STA1 and STA2 should include secondary channel S1.

[0046] Figure 7 An example of frequency channel allocation for two links is shown. For non-P2P links, P and S1 are allocated, but S2 and S3 are not allocated (or sometimes not allocated at all). In another example, S1 through S3 can be allocated as channel candidates for P2P links, but permission from the AP is required before S1 can be used for a P2P link, for example, because non-P2P links are given priority on S1.

[0047] To distinguish P2P links, the P2P link between STA1 and STA2 will be referred to as "P2P link 12" in the following text, and the P2P link between STA2 and STA3 will be referred to as "P2P link 23". P2P link 12 and interference link 2 are essentially the same, but the difference lies in whether a P2P link is established to send data.

[0048] After setting up the P2P link in step 1, STA2 sends a coordinated beamforming request to AP in step 2. Figure 6 The CBF request preferably includes one or more of the following indications: i) Request AP to send a CBF response to STA2; and ii) The maximum number of spatial flows in P2P link 23 during the upcoming CBF. .

[0049] In addition, a CBF request may include one or more of the following instructions: iii) The total number of STA2 spatial degrees of freedom that can be utilized in the upcoming CBF; iv) Permissible overlapping frequency channels between non-P2P links and P2P link 23 in the upcoming CBF; v) If traffic from STA2 to STA3 should be prioritized, then the preferred transmission time / duration of the CBF and the identifier of the CBF transmission; and vi) Does STA2 prioritize channel probing with STA3 on P2P link 23 after the CBF response?

[0050] The CBF request in step 2 can also be interpreted by the AP as such that after the AP sends a CBF response to STA2 in response to the CBF request, STA2 will at least perform a probe with STA1, or such an indication can also be included in the CBF request.

[0051] After the AP receives the CBF request from STA2 in step 2 ( Figure 6 In step 3, the AP sends a CBF response to STA2 (in the CBF res). The CBF response preferably includes one or more of the following indications: i) Permission to conduct CBF with STA2; ii) The minimum number of spatial degrees of freedom of the null trap from AP to STA3 during CBF; and iii) An indication of whether a feedback response (kernel feedback) is planned to be sent thereafter.

[0052] The CBF response may also include the maximum number of spatial streams on non-P2P links, the frequency channel for P2P link 12, and an indication of the frequency channel for P2P link 23.

[0053] In some implementations, CBF requests and CBF responses can be exchanged as part of the P2P link setup in step 1.

[0054] If the number of spatial streams sent by AP to STA1 is greater than Then the AP can decide to obtain a feedback response from STA3 (i.e., perform kernel feedback) and then instruct the plan to perform a feedback response (kernel feedback) thereafter.

[0055] If STA2 receives a CBF response in step 3 indicating a subsequent feedback response (kernel feedback) from STA3, STA2 can set up P2P link 12 and perform channel probing with STA1 on P2P link 12 to enable guided nulling in step 400. If STA1 and STA2 do not need any frame exchange, for example, if STA2 does not need to guide nulling to STA1 in step 4, this P2P link setup (i.e., step 4) can be skipped.

[0056] After receiving the CBF response in step 3, STA2 performs channel probing with STA1 (steps 5, 6, and 7) and STA3 (step 100, including steps 101, 102, and 103) to determine the steering matrix for P2P link 23. The channel probing between STA2 and STA1 is specifically designed to enable STA2 to guide nulls toward STA1 during the CBF in step 400. This channel probing, as well as the guiding nulls from STA2 to STA1, is optional and can be skipped in some implementations. Channel probing between STA2 and each of STA1 and STA3 allows STA2 to calculate the steering matrix (or set the beam), but can be skipped if each channel probing has already been performed before receiving the CBF response in step 4. If channel probing with STA3 has not been performed beforehand, it should be performed in step 100. Therefore, step 100 performs channel probing between STA2 and STA3, where STA2 sets the Tx beam to be used (for the steering matrix).

[0057] like Figure 6 As shown, in some implementations, STA2 sends a Null Data Packet Announcement (NDPA) (steps 5 and 101) before sending a Null Data Packet (NDP; also known as a training packet or training data) (steps 6 and 102). The NDPA and NDP can be designed and contain information as defined in the standard IEEE 802.11, but the NDPA (in step 101) may additionally include one or more of the following indications (hereinafter, FBCK request): i) The plan is to subsequently conduct probes for feedback (kernel feedback); ii) The destination of the feedback (kernel feedback) and / or the initiator of the probe used for the feedback (kernel feedback); and iii) Feedback Figure 6 The number of spatial streams that will be used on P2P link 23 after the kernel FBCK in the middle.

[0058] After receiving the NDP from STA2 (steps 6 and 102), STA1 and STA3 send CSI feedback (CSI FBCK) to STA2 in steps 6 and 103. The CSI feedback can be designed and includes information defined as compressed feedback in the standard IEEE 802.11.

[0059] In some implementations, such as Figure 6 As shown, the feedback request (kernel feedback request) Figure 6The FBCK req in step 200 can be included in the beamforming data unit (e.g., a PPDU (PHY Protocol Data Unit) or another NDP sent from STA2 to STA3 in a separate step 201 of step 200), or appended to the beamforming data unit instead of being included in the NDPA sent in step 101. Therefore, the feedback request is sent after the CSI feedback in step 103. In an optional step 202, STA3 can send an acknowledgment (Ack) to STA2. Thus, beamforming PPDU reception from STA2 is performed in step 200, where STA3 sets the Rx beam (or post-coded matrix) to be used.

[0060] During data unit transmission, STA2 can use (set) the steering matrix calculated from the CSI feedback (sent in step 103) from STA3. w 2 (i.e., STA2 sets the beam) so that STA3 can calculate the post-coding matrix for P2P link 23 before STA3 receives NDP from AP (step 301). P This enables STA3 to compute feedback responses (kernel feedback). If no beamforming data unit is sent to STA3 during the time from the P2P link setup for P2P link 12 (step 4) to the NDP transmission from the AP (step 301), STA3 can reuse the post-coded matrix that has already been used in previous communications with STA2.

[0061] After the detection / feedback (steps 100 and 200) is completed, the AP sends NDPA (step 301) and NDP (step 302) to STA3 for channel detection of interfering link 1. STA2 (or STA3) may optionally send a frame (in... Figure 6 In step 8, referred to as the probe request from STA3, this frame implicitly or explicitly requests the AP to perform an NDPA / NDP transmission, that is, to notify AP STA3 that it is ready for step 300. This probe request in step 8 can be designed and contain the same information as the CF (Contentless Competition) end frame defined in standard IEEE 802.11 to indicate the termination of STA2's TXOP (Transmission Opportunity).

[0062] If STA2 sends a probe request to AP in step 8 to request AP to perform channel probing of interfering link 1, this probe request may also include the estimated interference level at STA1 in the upcoming CBF. The estimated interference level can be derived from the CSI feedback from STA1 to STA2 (step 7) and the CSI feedback from STA3 to STA2 (step 103), for example, by using the following equation: The CSI indicated in the CSI feedback from STA1 to STA2. w 2 is The first eigenvector, p This is the expected transmit power of STA2 for P2P link 23 during CBF, and yes The first in i Line 1 j Column elements.

[0063] The NDPA in step 301 may be designed to include information as defined in standard IEEE 802.11, and it may also include an indication requesting feedback response (core feedback) from the expected receiver.

[0064] After receiving NDPA and NDP, STA3 sends a feedback response (kernel feedback) to AP in step 303. Therefore, in step 300, the transmission of the feedback response is initiated and executed, where STA3 will... Ph 2(= X Notify AP.

[0065] Upon receiving the feedback response, the AP calculates the steering matrix based on the feedback response and sends a trigger to STA2 to perform CBF (step 401). The time / duration can be determined based on the scheduling information received within the CBF request. Afterward, the AP and STA2 can perform CBF and simultaneously transmit data, for example, in PPDU format (steps 402, 403). Therefore, in step 400, the AP and STA2 are able to transmit simultaneously because the AP sets its Tx beam (or steering matrix) to reduce interference to the Rx beam of STA3. The AP can calculate the steering matrix. w AP As shown in the following equation:

[0066] in k It is a real number representing the power coefficient, and e It has the largest eigenvalue Z One of the feature vectors

[0067] in H 1 is the channel matrix between AP and STA1. It is the matrix indicated in the feedback response (kernel feedback). N It is the signal-to-noise ratio, and I It is an identity matrix.

[0068] Figure 8A diagram illustrating another embodiment of the communication scheme according to this disclosure is shown. In this embodiment, NDPA can be sent from the AP or simultaneously from both the AP (step 301) and STA2 (steps 5 and 101), as... Figure 8 As shown. In this case, NDP can be sent from both AP (step 302) and STA2 to STA1 (step 6) and STA3 (step 102) simultaneously, and feedback can also be sent from STA1 to AP (step 7) and STA2 (step 7) simultaneously or not simultaneously, and from STA3 to AP (step 303) and STA2 (step 103).

[0069] although Figure 8 Not shown, but an indication may be sent that the NDPA and subsequent NDP are intended for feedback responses (kernel feedback) to the jamming link. This indication may include information on which receivers are scheduled to send feedback responses (kernel feedback) to which transmitters. This indication may be included in the NDPA or sent before the NDPA. This indication may be expected by the receivers ( Figure 8 The explanation of STA3 in the text is such that after receiving a data frame from STA2 after FBCK (step 103), STA3 is requested to provide a feedback response.

[0070] Figure 9 A diagram illustrating another embodiment of the communication scheme according to this disclosure is shown. In this embodiment, NDPA (step 301), NDP (step 302), and feedback response (kernel feedback) (step 303) may immediately follow the CBF response. In this case, the indications in the feedback response (kernel feedback) can be derived under any of the following assumptions. Ph 2: i) When STA3 receives the PPDU that will be sent by CBF immediately, it uses a predetermined post-encoding matrix ( P ), such as DFT (Discrete Fourier Transform) matrices; or ii) STA3 uses the same post-encoding matrix when it receives the PPDU that will be sent by the CBF immediately thereafter. P ).

[0071] In step 404, trigger 404 is sent from STA2 to trigger AP and STA2 to simultaneously send PPDU in CBF (steps 402, 403).

[0072] Figure 10A flowchart of a communication method 500 that can be performed by an AP is shown. In a first step 501, the AP, in response to a coordinated beamforming (CBF) request, sends a CBF response to a second communication device configured to communicate with a third communication device. In a second step 502, the AP receives a feedback response from either the second or third communication device, the feedback response including post-coded information used by the third communication device to communicate with the second communication device and / or channel information of the channel between the access point and the third communication device. In a third step 503, the AP determines second guidance information, such as a second guidance matrix, based on the feedback response. In a fourth step, the AP uses the second guidance information to communicate with a first communication device and coordinates communication between the second and third communication devices.

[0073] Figure 11 A flowchart of a communication method 600 that can be performed by a second communication device (e.g., STA2) is shown. In a first step 601, STA2 sends a CBF request to an AP configured to communicate with both a first and a second communication device. In a second step 602, STA2 receives a CBF response from the AP in response to the CBF request. In a third step 603, STA2 sends a feedback request to a third communication device, requesting the third communication device to send a feedback response to the access point, the feedback response including post-coded information used by the third communication device to communicate with the second communication device and / or channel information of the channel between the AP and the third communication device.

[0074] Figure 12 A flowchart of a communication method 700 that can be performed by a third communication device (e.g., STA3) is shown. In a first step 701, STA3 receives training packets from an AP configured to communicate with a first communication device and a second communication device, and / or receives a feedback request from the second communication device to send a feedback response to the AP, the feedback response including post-coded information used by the third communication device to communicate with the second communication device. In a second step 702, STA3 sends a feedback response to the access point in response to the feedback request and / or one or more training packets.

[0075] The device can be implemented by corresponding units or circuits (e.g., processors, processing circuits, computers, dedicated hardware, etc.) that perform the functions of the device. Alternatively, a common unit or circuit (e.g., a common processor or computer) can implement the various functions of the device, or separate units or elements that together represent the circuit can be used.

[0076] Therefore, the foregoing discussion has only disclosed and described exemplary embodiments of this disclosure. As those skilled in the art will understand, this disclosure may be implemented in other specific forms without departing from the spirit or essential characteristics of this disclosure. Therefore, the disclosure of this disclosure is intended to be illustrative and not to limit the scope of this disclosure and the other claims. This disclosure (including any readily identifiable variations of the teachings herein) partially defines the scope of the foregoing claims, such that no inventive subject matter is offered to the public.

[0077] In the claims, the word "comprising" does not exclude other elements or steps, and the indefinite articles "a" or "an" do not exclude multiple. A single element or other unit can perform the functions of several items listed in the claims. The mere fact that certain measures are recited in different dependent claims does not indicate that a combination of these measures cannot be used to provide an advantage.

[0078] Since embodiments of this disclosure have been described as being implemented by a data processing apparatus at least in part by software control, it will be understood that non-transitory machine-readable media (such as optical discs, magnetic disks, semiconductor memories, etc.) carrying such software are also considered to represent embodiments of this disclosure. Furthermore, such software may be distributed in other forms, such as via the Internet or other wired or wireless telecommunications systems.

[0079] The elements of the disclosed devices, apparatuses, and systems can be implemented by corresponding hardware and / or software elements (e.g., suitable circuits or circuit systems). A circuit is a structural assembly of electronic components including conventional circuit elements, integrated circuits including application-specific integrated circuits (ASICs), standard integrated circuits, application-specific standard products, and field-programmable gate arrays (FPGAs). Furthermore, the circuit includes a central processing unit, a graphics processing unit, and a microprocessor programmed or configured according to software code. The circuit does not include pure software, but it includes the hardware that executes the aforementioned software. A circuit or circuit system can be implemented by a single device or unit, multiple devices or units, a chipset (or multiple chipsets), or a processor (or multiple processors).

[0080] Below is a list of other implementations of the disclosed subject matter: 1. An access point configured to communicate with a first communication device and a second communication device, the access point including circuitry configured to perform the following steps: - In response to a Coordinated Beamforming (CBF) request, a CBF response is sent to a second communication device configured to communicate with a third communication device; - Receive a feedback response from a second or third communication device, the feedback response including post-coded information used by the third communication device to communicate with the second communication device and / or channel information of the channel between the access point and the third communication device; - Determine the second guidance information based on the feedback response; and - Use the second guidance information to communicate with the first communication device, and coordinate the communication between the second and third communication devices.

[0081] 2. According to the access point of Implementation Method 1, The feedback response received from the second or third communication device includes information about the channel matrix and / or the product of the post-coding matrix and the channel matrix between the access point and the third communication device.

[0082] 3. According to the access point of implementation method 1 or 2, The CBF response includes information about the number or minimum number of spatial degrees of freedom that guide the null trap toward the third communication device during coordinated beamforming.

[0083] 4. The access point according to any of the foregoing embodiments, The CBF response includes: - Whether you expect to receive feedback response information from a third communication device, and / or - Instructions to send feedback requests or training packets from the access point to a third communication device.

[0084] 5. According to the access point of implementation method 4, In this process, a feedback request is sent in conjunction with the second communication device.

[0085] 6. The access point according to any of the foregoing embodiments, The circuit is configured to send training packets to a third communication device and optionally send training packet announcements, triggering the third communication device to send a feedback response.

[0086] 7. The access point according to any of the foregoing embodiments, The circuit is configured to determine a second steering matrix representing the second steering information such that the product of the post-coding matrix representing the post-coding information, the channel matrix representing the channel information, and the second steering matrix is ​​essentially zero.

[0087] 8. The access point according to any of the foregoing embodiments, The circuit is configured to communicate with the first communication device and coordinate with the communication between the second and third communication devices.

[0088] 9. An access point according to any of the foregoing embodiments, wherein the circuit is configured to send a feedback request to a third communication device after sending a CBF response to the second communication device in response to a CBF request from the second communication device.

[0089] 10. A second communication device configured to communicate with a third communication device and an access point, the second communication device including circuitry configured to perform the following steps: - Send a coordinated beamforming (CBF) request to the access point configured to communicate with the first and second communication devices. - In response to a CBF request, receive a CBF response from the access point; and - Send a feedback request to a third communication device, thereby requesting the third communication device to send a feedback response to the access point, the feedback response including post-encoded information used by the third communication device to communicate with the second communication device and / or channel information of the channel between the access point and the third communication device.

[0090] 11. The second communication device according to embodiment 10, The circuit is configured to send a feedback request to a third communication device, thereby requesting the third communication device to send a feedback response to the access point in response to the training packets received from the access point.

[0091] 12. The second communication device according to embodiment 10 or 11, The circuit is configured to communicate with a third communication device via a direct link and / or transmit channel information of the channel between the access point and the third communication device via a direct link.

[0092] 13. The second communication device according to any one of embodiments 10 to 12, The circuit is configured to send a feedback request as part of a data unit, or to send a feedback request attached to a data unit sent to a third communication device.

[0093] 14. The second communication device according to any one of embodiments 10 to 13, The circuit is configured as follows: - First guidance information, specifically a first guidance matrix, is determined based on first channel information of the channel between the second and third communication devices; and - Send feedback requests as separate information or as first guiding information included in or attached to a data unit.

[0094] 15. A second communication device according to any one of embodiments 10 to 14, The circuit is configured to communicate with a third communication device after sending a feedback request and in response to a trigger from the access point, and to coordinate the communication between the access point and the first communication device.

[0095] 16. A second communication device according to any one of embodiments 10 to 15, The circuit is configured to send a training packet to the third communication device and optionally send a training packet announcement before sending a feedback request to the third communication device, thereby triggering the third communication device to send first channel information of the channel between the second and third communication devices.

[0096] 17. A second communication device according to any one of embodiments 10 to 16, The circuit is configured to include one or more of the following in the training group announcement: - Information regarding the planned probes used to generate a feedback response; - The destination of the feedback response; and - The number of spatial streams that will be used for communication between the second and third communication devices on the direct link during coordinated beamforming.

[0097] 18. A second communication device according to any one of embodiments 10 to 17, The circuit is configured as follows: - Upon receiving the CBF request, a training packet is sent to the first communication device, and optionally a training packet announcement is sent, thereby triggering the first communication device to send fourth channel information of the channel between the second communication device and the first communication device; and - A fourth steering matrix is ​​determined based on the fourth channel information to guide nulls to the first communication device during coordinated beamforming.

[0098] 19. The second communication device according to embodiments 17 and 18, The circuit is configured to simultaneously send training packets to the first communication device and the third communication device, and optionally send training packet announcements, and optionally simultaneously send training packets from the access point to the third communication device, and optionally send training packet announcements.

[0099] 20. A second communication device according to any one of embodiments 10 to 19, The circuit is configured to send a probe request to the access point after sending a feedback request, thereby notifying the access point that the third communication device is ready to generate a feedback response.

[0100] 21. A third communication device configured to communicate with a second communication device, the third communication device including circuitry configured to perform the following steps: - Receive training packets from an access point configured to communicate with a first communication device and a second communication device, and / or receive a feedback request from the second communication device to send a feedback response to the access point, the feedback response including post-coded information for communication between the third communication device and the second communication device; and - In response to feedback requests and / or training groups, send feedback responses to the access point.

[0101] 22. The third communication device according to embodiment 21, The circuit is configured to communicate with a second communication device via a direct link, and / or the feedback response includes post-coded information from a third communication device for communicating with the second communication device via a direct link.

[0102] 23. The third communication device according to embodiment 21 or 22, The circuit is configured to determine post-encoded information based on one or more data units received from the second communication device.

[0103] 24. A third communication device according to any one of embodiments 21 to 23, The circuit is configured to include second channel information of the channel between the access point and the third communication device in the feedback response.

[0104] 25. A third communication device according to any one of embodiments 21 to 24, The circuit is configured to include in the feedback response a post-encoded matrix representing post-encoded information for communication between the third communication device and the second communication device, and a channel matrix representing channel information of the channel between the access point and the third communication device.

[0105] 26. A third communication device according to any one of embodiments 21 to 25, The circuit is configured to send first channel information of the channel between the second and third communication devices to the second communication device before receiving a feedback request.

[0106] 27. A third communication device according to any one of embodiments 21 to 26, The circuit is configured to communicate with the second communication device after sending a feedback response and in response to a trigger from the access point, and to coordinate the communication between the access point and the first communication device.

[0107] 28. A communication method for an access point configured to communicate with a first communication device and a second communication device, the access point including circuitry configured to perform the following steps: - In response to a Coordinated Beamforming (CBF) request, a CBF response is sent to a second communication device configured to communicate with a third communication device; - Receive a feedback response from a second or third communication device, the feedback response including post-coded information used by the third communication device to communicate with the second communication device and / or channel information of the channel between the access point and the third communication device; - Determine the second guidance information based on the feedback response; and - Use the second guidance information to communicate with the first communication device, and coordinate the communication between the second and third communication devices.

[0108] 29. A communication method for a second communication device configured to communicate with a third communication device and an access point, the second communication device including circuitry configured to perform the following steps: - Send a coordinated beamforming (CBF) request to the access point configured to communicate with the first and second communication devices. - In response to a CBF request, receive a CBF response from the access point; and - Send a feedback request to a third communication device, thereby requesting the third communication device to send a feedback response to the access point, the feedback response including post-encoded information used by the third communication device to communicate with the second communication device and / or channel information of the channel between the access point and the third communication device.

[0109] 30. A communication method for a third communication device configured to communicate with a second communication device, the third communication device comprising circuitry configured to perform the following steps: - Receive training packets from an access point configured to communicate with a first communication device and a second communication device, and / or receive a feedback request from the second communication device to send a feedback response to the access point, the feedback response including post-coded information for communication between the third communication device and the second communication device; and - In response to a feedback request and / or one or more training groups, send a feedback response to the access point.

[0110] 31. A non-transitory computer-readable recording medium storing a computer program product therein, which, when executed by a processor, causes the method according to embodiment 28, 29 or 30 to be performed.

[0111] 32. A computer program, including program code units, which, when executed on a computer, cause the computer to perform steps in the method according to embodiments 28, 29, or 30.

Claims

1. An access point configured to communicate with a first communication device and a second communication device, the access point comprising circuitry configured to: - In response to a Coordinated Beamforming (CBF) request, a CBF response is sent to the second communication device, which is configured to communicate with a third communication device; - Receive a feedback response from the second communication device or the third communication device, the feedback response including post-encoded information of the third communication device for communicating with the second communication device and / or channel information of the channel between the access point and the third communication device; - Determine the second guidance information based on the feedback response; and - Use the second guidance information to communicate with the first communication device and coordinate the communication between the second communication device and the third communication device.

2. The access point according to claim 1, in, The feedback response received from the second communication device or the third communication device includes information about the product of the channel matrix and / or the post-coding matrix of the channel between the access point and the third communication device and the channel matrix between the access point and the third communication device.

3. The access point according to claim 1, in, The CBF response includes: - Information regarding the number or minimum number of spatial degrees of freedom guiding the nulls to the third communication device during coordinated beamforming; and / or - Whether you expect to receive the feedback response from the third communication device, and / or - Send a feedback request or training group instruction from the access point to the third communication device.

4. The access point according to claim 1, in, The circuit is configured to send training packets to the third communication device and optionally send training packet announcements, triggering the third communication device to send the feedback response.

5. The access point according to claim 1, in, The circuit is configured to send a feedback request to the third communication device after sending a CBF response to the second communication device in response to the CBF request from the second communication device.

6. A second communication device configured to communicate with a third communication device and an access point, the second communication device comprising circuitry configured to: - Send a Coordinated Beamforming (CBF) request to an access point configured to communicate with the first communication device and the second communication device; - In response to the CBF request, receive a CBF response from the access point; as well as - Send a feedback request to the third communication device, requesting the third communication device to send a feedback response to the access point, the feedback response including post-encoded information used by the third communication device to communicate with the second communication device and / or channel information of the channel between the access point and the third communication device.

7. The second communication device according to claim 6, in, The circuit is configured as follows: - Send the feedback request to the third communication device, requesting the third communication device to send a feedback response to the access point in response to the training packet received from the access point; and / or - Simultaneously send the training packet to the first communication device and the third communication device, and optionally send a training packet announcement, and optionally simultaneously send the training packet from the access point to the third communication device, and optionally send a training packet announcement; And / or, - After sending the feedback request, a probe request is sent to the access point to notify the access point that the third communication device is ready to generate the feedback response.

8. The second communication device according to claim 6, in, The circuit is configured as follows: - Communicate with the third communication device via a direct link, and / or transmit channel information of the channel between the access point and the third communication device via the direct link; and / or - After sending the feedback request and in response to a trigger from the access point, communicate with the third communication device and coordinate the communication between the access point and the first communication device.

9. The second communication device according to claim 6, in, The circuit is configured as follows: - First guidance information, specifically a first guidance matrix, is determined based on first channel information of the channel between the second communication device and the third communication device; and - The feedback request is sent using the first guidance information, either as separate information or included in or attached to the data unit.

10. The second communication device according to claim 6, in, The circuit is configured to send a training packet to the third communication device and optionally send a training packet announcement before sending the feedback request to the third communication device, thereby triggering the third communication device to send first channel information of the channel between the second communication device and the third communication device.

11. The second communication device according to claim 10, in, The circuit is configured to include one or more of the following in the training group announcement: - Information to be probed to generate the feedback response; - The destination of the feedback response; as well as - The number of spatial streams that will be used for communication between the second and third communication devices on the direct link during coordinated beamforming.

12. The second communication device according to claim 6, in, The circuit is configured as follows: - Upon receiving the CBF request, a training group is sent to the first communication device and optionally a training group notification is sent, triggering the first communication device to send fourth channel information of the channel between the second communication device and the first communication device; as well as - A fourth steering matrix is ​​determined based on the fourth channel information to guide nulls toward the first communication device during coordinated beamforming.

13. A third communication device configured to communicate with a second communication device, the third communication device comprising circuitry configured to: - Receive training packets from an access point configured to communicate with a first communication device and a second communication device, and / or receive a feedback request from the second communication device to send a feedback response to the access point, the feedback response including post-encoded information used by the third communication device to communicate with the second communication device; and - In response to the feedback request and / or the training group, send the feedback response to the access point.

14. The third communication device according to claim 13, in, The circuit is configured to communicate with the second communication device via a direct link, and / or the feedback response includes post-coded information from the third communication device for communicating with the second communication device via the direct link.

15. The third communication device according to claim 13, in, The circuit is configured to include in the feedback response: - Second channel information of the channel between the access point and the third communication device, and / or - The third communication device uses a post-encoding matrix representing the post-encoding information for communicating with the second communication device, and a channel matrix representing the channel information between the access point and the third communication device.

16. The third communication device according to claim 13, in, The circuit is configured to send first channel information of the channel between the second communication device and the third communication device to the second communication device before receiving the feedback request.

17. A communication method for an access point configured to communicate with a first communication device and a second communication device, the access point comprising circuitry configured to: - In response to a Coordinated Beamforming (CBF) request, a CBF response is sent to a second communication device configured to communicate with a third communication device; - Receive a feedback response from the second communication device or the third communication device, the feedback response including post-encoded information of the third communication device for communicating with the second communication device and / or channel information of the channel between the access point and the third communication device; - Determine the second guidance information based on the feedback response; and - Use the second guidance information to communicate with the first communication device and coordinate the communication between the second communication device and the third communication device.

18. A communication method for a second communication device configured to communicate with a third communication device and an access point, the second communication device comprising circuitry configured to: - Send a Coordinated Beamforming (CBF) request to an access point configured to communicate with the first communication device and the second communication device; - In response to the CBF request, receive a CBF response from the access point; as well as - Send a feedback request to the third communication device, requesting the third communication device to send a feedback response to the access point, the feedback response including post-encoded information used by the third communication device to communicate with the second communication device and / or channel information of the channel between the access point and the third communication device.

19. A communication method for a third communication device configured to communicate with a second communication device, the third communication device comprising circuitry configured to: - Receive training packets from an access point configured to communicate with a first communication device and a second communication device, and / or receive a feedback request from the second communication device to send a feedback response to the access point, the feedback response including post-encoded information used by the third communication device to communicate with the second communication device; and - In response to the feedback request and / or one or more training groups, send the feedback response to the access point.

20. A non-transitory computer-readable recording medium storing a computer program product, which, when executed by a processor, causes to perform the method according to claim 17, 18 or 19.

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