Communication device and communication method

Abstract

The present application improves the transmission efficiency in a multi-link. A communication device includes a control circuit that controls a multi-link transmission based on control information related to the multi-link transmission, and a transmission circuit that performs the multi-link transmission according to the control of the multi-link transmission.

Description

Technical Field

[0001] This disclosure relates to communication devices and communication methods. Background Technology

[0002] As a successor to the IEEE 802.11 standard, namely 802.11ax (hereinafter referred to as "11ax"), the Task Group (TG) is planning to develop the technical specifications for 802.11be (hereinafter referred to as "11be").

[0003] In 11be, for example compared to 11ax, the increase of the maximum number of spatial streams in downlink (DL) multi-user multiple-input multiple-output (MU-MIMO) (e.g., also referred to as "spatial stream number" or "spatial multiplexing number") is discussed. By increasing the maximum number of spatial streams, spectral efficiency can be improved.

[0004] Existing technical documents

[0005] Non-patent literature

[0006] Non-patent literature 1: IEEE 802.11-19 / 0828r4, feedback-overhead-analysis-for-16-spatial-stream-mimo, May, 2019

[0007] Non-patent document 2: IEEE P802.11ax D6.0, November 2019

[0008] Non-patent document 3: IEEE Std 802.11, 2016

[0009] Non-patent document 4: IEEE 802.11-19 / 0823r2, Multi-Link Operation: Design Discussion Summary of the Invention

[0010] However, there is still room for research on transmission processing in multi-link systems.

[0011] The non-limiting embodiments disclosed herein help to provide communication apparatus and methods for improving transmission efficiency in multi-link systems.

[0012] One embodiment of the communication apparatus disclosed herein includes: a control circuit that controls the transmission of the first information based on second information relating to the transmission of first information in a plurality of links; and a transmission circuit that transmits the first information according to the control.

[0013] It should be noted that these general or specific methods can be implemented by systems, devices, methods, integrated circuits, computer programs, or recording media, or by any combination of systems, devices, methods, integrated circuits, computer programs, and recording media.

[0014] According to one embodiment of this disclosure, transmission efficiency in multi-link systems can be improved.

[0015] Further advantages and effects of one embodiment of this disclosure will be clearly presented by the specification and accompanying drawings. These advantages and / or effects are provided by various embodiments and the features described in the specification and drawings, but it is not necessary for all of them to be provided in order to obtain one or more of the same features. Attached Figure Description

[0016] Figure 1 This is a sequence diagram illustrating an example of beamforming using null data packet (NDP) sounding and explicit feedback.

[0017] Figure 2 This is a diagram illustrating an example of the frame actionfield format for High Efficiency (HE) Compressed Beamforming / CQI (Channel Quality Indicator).

[0018] Figure 3 This is a sequence diagram illustrating an example of staggered sounding.

[0019] Figure 4 This is a diagram illustrating an example of a multi-link operation system.

[0020] Figure 5 This is a diagram illustrating the operation of a multi-link device (MLD) that simultaneously transmits and receives (STR: Simultaneous Tx and Rx).

[0021] Figure 6This is a diagram representing an example of a non-STR AP MLD action.

[0022] Figure 7 This is a block diagram illustrating a structural example of a portion of the AP MLD in Implementation 1.

[0023] Figure 8 This is a block diagram illustrating a structural example of a non-AP MLD in Implementation 1.

[0024] Figure 9 This is a block diagram illustrating a structural example of the AP MLD in Implementation Method 1.

[0025] Figure 10 This is a block diagram illustrating a structural example of a non-AP MLD in Implementation Method 1.

[0026] Figure 11 This is a sequence diagram illustrating an example of the operation of the wireless communication system according to Implementation Method 1.

[0027] Figure 12 This is a diagram representing an example of a Link ID bitmap.

[0028] Figure 13 This is a diagram representing an example of a link ID bitmap.

[0029] Figure 14 This is a sequence diagram representing an example of a feedback information sending action.

[0030] Figure 15 This is a sequence diagram representing an example of a feedback information sending action.

[0031] Figure 16 This is a sequence diagram representing an example of a feedback information sending action.

[0032] Figure 17 This is a sequence diagram representing an example of a feedback information sending action.

[0033] Figure 18 This is a diagram showing an example of the fields representing the start and end points of a notification space stream.

[0034] Figure 19 This is a diagram showing an example of the fields representing the start and end points of the notification channel index.

[0035] Figure 20 This is an example diagram of a field that represents the type of notification or feedback information.

[0036] Figure 21 This is a diagram representing an example of a feedback request signal.

[0037] Figure 22This is a diagram illustrating a setting example for a feedback request signal.

[0038] Figure 23 This is a diagram representing an example of a trigger frame.

[0039] Figure 24 This is a diagram representing an example of a trigger frame.

[0040] Figure 25 This is a sequence diagram illustrating an example of the operation of the wireless communication system in Implementation Method 2.

[0041] Figure 26 This is a diagram representing an example of an NDP Announcement (NDPA).

[0042] Figure 27 This is a diagram illustrating an example of feedback information.

[0043] Figure 28 This is a diagram illustrating an example of HE MIMO control.

[0044] Figure 29 This is a sequence diagram illustrating an example of the operation of a wireless communication system in other implementations.

[0045] Figure 30 This is a sequence diagram illustrating an example of the operation of a wireless communication system in other implementations.

[0046] Figure 31 This is a diagram of an example of a field representing a combination of notification frequency band and channel identifier.

[0047] Figure 32 This is a diagram illustrating an example of frequency band and channel identifiers.

[0048] Figure 33 This is a diagram illustrating an example of the combination of frequency band and frequency offset.

[0049] Figure 34 This is a diagram illustrating an example of frequency band and frequency shift. Detailed Implementation

[0050] Hereinafter, various embodiments of the present disclosure will be described in detail with reference to the accompanying drawings.

[0051] In the 802.11 standard specification, for example, without space-time block coding (also known as "Space-Time Block Coding (STBC)"), one bitstream generates one modulation symbol stream; with STBC, one bitstream generates two or more modulation symbol streams. For example, spatially multiplexed bitstreams can be called "spatial streams," and spatially multiplexed modulation symbol streams can be called "space-time streams" (or, also known as "Space-timestreams (STS)") for distinction. For example, without STBC, the number of space-time streams is equal to the number of spatial streams.

[0052] In the following description, examples without spatiotemporal block coding are illustrated. In other words, in the following description, the term "spatial stream" is used interchangeably with "spatial stream," meaning a spatial channel used for spatial multiplexing. However, the spatial stream in the following description can also be understood as a spatiotemporal stream with spatiotemporal block coding.

[0053] Beamforming

[0054] In DL MU-MIMO, beamforming technology is used. Beamforming technology can be leveraged to improve communication quality in DL.

[0055] In DL MU-MIMO beamforming, for example, in order to add orthogonality to the signals sent to each user, weighting of amplitude and phase is performed (e.g., also called "steering", "spatial mapping", or "precoding"). For example, a matrix representing this weighting (hereinafter referred to as "steering matrix") can be derived based on information of the transmission path (e.g., also called "channel") estimated by beamforming (see, for example, Non-Patent Document 1).

[0056] As an example of beamforming methods, 11ax supports a method using null data packet (NDP) probes and explicit feedback (e.g., see Non-Patent Literature 2). Figure 1 This is a sequence diagram illustrating an example of beamforming using NDP detection and explicit feedback.

[0057] exist Figure 1 In this context, the access point ("AP", or "base station") sends NDP announcements (NDPAs) to each terminal (e.g., also called "STA"). By sending NDPAs, the AP notifies the STA of the NDP's transmission.

[0058] Next, NDPA is applied, and the AP sends the NDP to the STA.

[0059] After receiving the NDP, the STA estimates the channel based on the signals contained in the NDP (e.g., non-legacy long training field).

[0060] Furthermore, for example, when a steering matrix is ​​attached to a non-legacy LTF, the STA can estimate the channel (e.g., also called the "effective channel") including the steering matrix, regardless of whether the received signal is NDP or non-NDP. In the following description, both the channel and the effective channel are simply referred to as the "transmission path response" (also called "transmission path characteristic," "channel response," "channel estimation matrix," or "channel matrix"). The STA, for example, determines the feedback information to send to the AP based on the channel estimate in response to the NDP.

[0061] For example, the STA sends compressed feedback information to the AP using a method called "compressed beamforming". The AP receives and processes the feedback information sent from the STA and, based on the received feedback information, determines (also called "schedules") the resource allocation information and transmission parameters for the destination STA or each STA. Additionally, the AP performs deep learning (DL) transmissions to the STAs (e.g., MU-MIMO), thus allowing the steering matrix to be derived based on the feedback information.

[0062] Figure 2 This is a structure example representing the feedback information sent by the STA to the AP. As an example, Figure 2 This is a structural example representing the format of the compressed beamforming / CQI frame behavior field. Additionally, as an example, Figure 2 This represents a structure example for the case where the feedback type is MU (Multi-User).

[0063] Feedback information is categorized, for example, as "HE Compressed Beamforming Report," "HE MU Exclusive Beamforming Report," and "HE Channel Quality Information (CQI) Report." The HE Compressed Beamforming Report may include, for example, the received quality (e.g., average signal-to-noise ratio (SNR)) for each spatial stream, and a feedback matrix that compresses the information using a specified method. Additionally, the HE MU Exclusive Beamforming Report may include, for example, the difference between the received quality (e.g., SNR) of each subcarrier and the average received quality (e.g., average SNR) of all spatial streams. Furthermore, the HE CQI report may include, for example, the average received quality (e.g., average SNR) of the spatial streams in units of 26-tone resource units (RUs).

[0064] The STA can, for example, determine the feedback information to send to the AP as a response to the NDP based on the feedback type notified in the "Feedback Type and Ngsubfield" contained in the NDPA. For example, in the case of feedback type = SU (Single User), the STA can send a HE compressed beamforming report. Additionally, in the case of feedback type = MU (e.g., ...), Figure 2 The STA can provide HE compressed beamforming reports and HE MU exclusive beamforming reports. Additionally, when the feedback type is CQI, the STA can provide HE CQI reports.

[0065] In addition, as an example of other beamforming methods, 802.11n supports “interleaved detection” (e.g., see Non-Patent Document 3).

[0066] Figure 3 This is a sequence diagram representing an example of interleaved detection.

[0067] Interleaving detection is a beamforming method used in single-user MIMO (SU-MIMO). The AP, for example, transmits a signal containing a data section (e.g., a SU Physical Layer Convergence Procedure Protocol Data Unit) to the STA. The STA, for example, determines whether to send feedback information based on the channel state information (CSI) / steering request contained in the medium access control (MAC) layer of the signal transmitted from the AP. If instructed to send feedback information (in the case of "yes"), the STA provides feedback based on a channel estimate obtained from the signal contained in the signal transmitted from the AP (e.g., a non-legacy LTF). For example, the STA may add the channel estimate (in other words, feedback information) to a response signal (e.g., an acknowledgment (ACK) or a block acknowledgment (BA)) based on the feedback method indicated by the CSI / steering request and send it to the AP.

[0068] [Multi-link actions]

[0069] In 11be, multi-link operation (hereinafter referred to as "multi-link") is discussed, that is, a multi-link device (MLD) in which multiple APs or STAs are connected to a MAC service access point (SAP) and use multiple links to send and receive with each other (e.g., send and receive simultaneously) (e.g., see Non-Patent Document 4).

[0070] In multi-link systems, throughput and latency can be improved, for example, by transmitting (e.g., simultaneously) MAC Service Data Units (MSDUs) with a single Traffic Identifier (TID).

[0071] Figure 4 This is a diagram illustrating an example of a multi-link system. In Figure 4 In the example shown, a multi-link system using Link 1 and Link 2 is used between AP1 and AP2 and STA1 and STA2.

[0072] In a multi-link system, the MLD containing an AP is called an "AP MLD," and the MLD containing a STA that is not an AP is called a "non-AP MLD." Furthermore, the links used in a multi-link system can be multiple links within the same frequency band or multiple links in different frequency bands.

[0073] Furthermore, AP MLDs / non-AP MLDs that can transmit and receive on multiple links (e.g., simultaneously) are referred to as "Simultaneous Transmit and Receive (STR) AP MLDs / STR Non-AP MLDs". On the other hand, AP MLDs / non-AP MLDs that cannot transmit and receive on multiple links are referred to as "Non-STR AP MLDs / Non-STR Non-AP MLDs".

[0074] Figure 5 This is a diagram representing an example of the action of STR AP MLD. Figure 6 This is a diagram representing an example of a non-STR AP MLD action. In Figure 5 In this context, the STR AP MLD, for example, can simultaneously receive an ACK signal (Ack) from the STA in link 1 and transmit data to the STA in link 2. On the other hand, in... Figure 6 In non-STR AP MLD, for example, simultaneous transmission and reception on multiple links are not allowed (or avoided). Therefore, it is possible to schedule the data transmission timing to avoid overlap with the ACK signal reception timing when data transmission on each link occurs at different times.

[0075] The above explains the concept of multi-link systems.

[0076] However, methods for transmitting feedback information from the STA to the AP in a multi-link system (e.g., multi-link feedback) have not been sufficiently studied. For example, the amount of feedback information transmitted from the STA to the AP increases proportionally to the maximum number of spatial streams. Therefore, for the I1be system, which can increase the maximum number of spatial streams, methods to improve transmission efficiency in a multi-link system (e.g., frequency utilization efficiency of multi-link feedback) are desired.

[0077] In one embodiment of this disclosure, a method for improving frequency utilization efficiency in multi-link feedback is described.

[0078] [Structure of a wireless communication system]

[0079] One embodiment of the wireless communication system disclosed herein includes at least one AP MLD and one non-AP MLD.

[0080] For example, an AP MLD (also known as a "downlink radio transmitter" in DL communication) transmits control information to a non-AP MLD (also known as a "downlink radio receiver" in DL communication). The non-AP MLD, for example, transmits feedback information to the AP MLD from one or more links specified by the control information (e.g., uplink (UL) SU transmission, or UL MU transmission).

[0081] Hereinafter, for example, the case where the device contained in the wireless communication system is an MLD is taken as a non-limiting example. For convenience, AP MLD is sometimes referred to as "AP", and non-AP MLD is referred to as "STA".

[0082] Furthermore, an MLD (e.g., an AP MLD or a non-AP MLD) can be, for example, a device having more than one STA (e.g., an affiliated STA attached to the MLD). Additionally, an MLD can be, for example, a device that, for logical link control (e.g., logical link control (LLC)), has a MAC SAP that includes a MAC data service.

[0083] Furthermore, MLDs can be constructed logically or physically. For example, an MLD can also have characteristics similar to... Figure 4 The multiple links shown correspond to a single physical device representing the logical function of a STA or AP. Alternatively, for example, an MLD can also be composed of... Figure 4 The multiple links shown are each composed of a dedicated physical device (STA or AP).

[0084] Additionally, an MLD can also have a STA. Furthermore, the MAC addresses (e.g., wireless medium MAC addresses) of multiple STAs contained in an MLD (e.g., subsidiary STAs) can be the same or different.

[0085] Additionally, an AP MLD can be, for example, an MLD that includes an AP (in other words, an MLD whose associated STA is an AP). Conversely, a non-AP MLD can be, for example, an MLD that includes an STA (in other words, an MLD whose associated STA is a non-AP STA).

[0086] The following is an example illustrating the method in which, during NDP probing in 11ax, the STA performs multi-link feedback transmission based on control information sent by the AP.

[0087] Figure 7This is a block diagram illustrating a structural example of AP100, an embodiment of the present disclosure. Figure 7 In the AP100 shown (e.g., equivalent to a communication device), the control unit (e.g., equivalent to a control circuit) controls the reception of multi-link transmissions from other communication devices (e.g., STA200) based on control information related to multi-link transmission. The receiving unit (e.g., a receiving circuit) receives the multi-link transmissions from other communication devices according to the control of reception.

[0088] Figure 8 This is a block diagram illustrating a structural example of a STA200 according to an embodiment of the present disclosure. Figure 8 In the STA200 shown (e.g., equivalent to a communication device), the control unit (e.g., equivalent to a control circuit) controls multi-link transmission based on control information related to multi-link transmission. The transmission unit (e.g., equivalent to a transmission circuit) performs multi-link transmission according to the control of multi-link transmission.

[0089] (Implementation Method 1)

[0090] <Structural Example of AP100>

[0091] Figure 9 This is a block diagram representing a structural example of AP100 (e.g., a downlink wireless transmitter or AP MLD). Figure 9 The AP100 shown may include, for example, a wireless receiver 101-1, a wireless receiver 101-2, a received signal decoding unit 102, a feedback information reconstruction unit 103, a multi-link scheduling unit 104, a data generation unit 105, a preamble generation unit 106, a wireless transmitter 107-1, and a wireless transmitter 107-2.

[0092] Furthermore, for example, the received signal decoding unit 102, the feedback information reconstruction unit 103, the multi-link scheduling unit 104, the data generation unit 105, and the preamble generation unit 106 may be included in... Figure 7 The control unit and wireless receivers 101-1 and 101-2 shown may be included in Figure 7 The receiving unit shown.

[0093] Additionally, for example, the wireless receiver 101-1 and the wireless transmitter 107-1 are access points (APs) that communicate using link 1 (e.g., Figure 4 The structure of AP1 shown, including the wireless receiver 101-2 and the wireless transmitter 107-2, is an AP that communicates using link 2 (e.g., Figure 4 The structural part of AP2 shown.

[0094] In addition, although Figure 9The diagram shows an example of an AP100 with two links, but the number of links is not limited to two; it can also be three or more.

[0095] The wireless receiving units 101-1 and 101-2 of each link receive signals transmitted from the STA200 (e.g., a downlink wireless receiving device or a non-AP MLD) via antennas, and perform wireless reception processing such as down-conversion and A / D (Analog-to-Digital) conversion on the received signals. For example, the wireless receiving units 101-1 and 101-2 divide the wirelessly processed received signal into a preamble section (also called a "preamble signal") and a data section (also called a "data signal"), and output them to the received signal decoding unit 102.

[0096] The receiving signal decoding unit 102 can, for example, perform demodulation processing such as Fourier transform (e.g., Fast Fourier Transform (FFT)) on the preamble signals and data signals input from the respective wireless receiving units 101-1 and 101-2 of each link, and extract the control signals contained in each of the preamble signals and data signals. The control signals may, for example, include bandwidth, modulation and channel coding scheme (MCS), or coding method.

[0097] Furthermore, the receiving signal decoding unit 102 can, for example, use control signals and channel estimation signals obtained from the preamble signal to perform channel equalization on the FFT-derived data signal, and then demodulate and decode it, thereby performing error detection such as Cyclic Redundancy Check (CRC). For example, if the data signal is error-free (in other words, if the decoding is faulty), the receiving signal decoding unit 102 outputs the decoded data signal to the feedback information reconstruction unit 103 and the multi-link scheduling unit 104. On the other hand, if the data signal is faulty, the receiving signal decoding unit 102 may not output the decoded data signal.

[0098] The feedback information reconstruction unit 103 reconstructs the feedback information input from the received signal decoding unit 102, for example, based on the data signal (e.g., control information related to the feedback information allocation method) input from the received signal decoding unit 102, according to the link or according to the type of feedback information. The feedback information reconstruction unit 103 can output the reconstructed feedback information to a processing unit (not shown). Furthermore, "allocation method" can be simply referred to as "allocation," and can also be interchanged with other terms such as "allocation (method)" or "mapping (method)" for multiple links.

[0099] The multi-link scheduling unit 104 performs multi-link scheduling, for example.

[0100] For example, the multi-link scheduling unit 104 can determine whether to request multi-link feedback transmission from STA200 based on the data signal input from the received signal decoding unit 102 (e.g., information related to the status of each link of STA200 (e.g., Network Allocation Vector (NAV) status information)).

[0101] For example, when a multi-link feedback transmission is requested from the STA200, the multi-link scheduling unit 104 determines the scheduling of the multi-link feedback transmission based on the data signal input from the received signal decoding unit 102. Examples of scheduling for multi-link feedback transmission include: scheduling of the transmission of control information related to the links used for multi-link feedback, scheduling related to the links in the STA200 used for transmitting feedback information, and scheduling related to the allocation of feedback information for each link in the STA200. The multi-link scheduling unit 104 outputs the scheduling-related control information, for example, to at least one of the data generation unit 105 and the preamble generation unit 106.

[0102] The data generation unit 105 generates, for example, data sequences to be transmitted to the STA 200 in each link based on scheduling information input from the multi-link scheduling unit 104. The data generation unit 105 may encode the generated data sequences, allocate the encoded data sequences to the frequency band of a channel (e.g., a channel obtained through carrier sensing), perform modulation and inverse Fourier transform (e.g., IFFT) processing, and generate data signals. The data generation unit 105 outputs the generated data signals to the wireless transmission units 107-1 and 107-2 of each link.

[0103] The preamble generation unit 106 generates a preamble signal based on scheduling information input from the multi-link scheduling unit 104. The preamble signal may include, for example, a reference signal. For instance, the preamble generation unit 106 modulates and performs IFFT processing on the preamble signal, and outputs the preamble signal to the wireless transmission units 107-1 and 107-2 of each link.

[0104] The wireless transmitting units 107-1 and 107-2 of each link generate wireless frames (e.g., also referred to as "packet signals"), which contain data signals input from the data generation unit 105 and preamble signals input from the preamble generation unit 106. The wireless transmitting units 107-1 and 107-2 perform wireless transmission processing on the generated wireless frames, such as D / A (Digital-to-Analog) conversion and up-conversion to the carrier frequency, and transmit the processed signals to the STA200 via antennas.

[0105] <Structural Example of STA200>

[0106] Figure 10 This is a block diagram representing a structural example of STA200 (e.g., a downlink wireless receiver or a non-AP MLD). Figure 10 The STA200 shown may include, for example, a wireless receiver 201-1, a wireless receiver 201-2, a preamble demodulation unit 202-1, a data decoding unit 203-1, a multi-link control unit 204, a transmission signal generation unit 205, a wireless transmitter 206-1, and a wireless transmitter 206-2.

[0107] Furthermore, for example, preamble demodulation unit 202-1, preamble demodulation unit 202-2, data decoding unit 203-1, data decoding unit 203-2, multi-link control unit 204, and transmission signal generation unit 205 may be included in Figure 8 The control unit and wireless transmission units 206-1 and 206-2 shown may be included in Figure 8 The transmitting unit is shown.

[0108] Additionally, for example, the wireless receiver 201-1, the preamble demodulation unit 202-1, the data decoding unit 203-1, and the wireless transmitter 206-1 are STAs that communicate using Link 1 (e.g., Figure 4 The structure of the STA1 shown includes a wireless receiver 201-2, a preamble demodulation unit 202-2, a data decoding unit 203-2, and a wireless transmitter 206-2, which are STAs that communicate using link 2 (e.g., Figure 4 The structural part of STA2 shown.

[0109] In addition, although Figure 10 The diagram shows a STA200 configuration with two links, but the number of links is not limited to two; it can also be three or more.

[0110] The wireless receiving units 201-1 and 201-2 of each link receive signals transmitted from AP100 via antennas and perform wireless reception processing such as down-conversion and A / D conversion on the received signals. The wireless receiving units 201-1 and 201-2 extract the preamble signal from the wirelessly received signals and output it to the preamble demodulation units 202-1 and 202-2. Additionally, the wireless receiving units 201-1 and 201-2 extract the data signal from the wirelessly received signals and output it to the data decoding units 203-1 and 203-2.

[0111] Each link's preamble demodulation units 202-1 and 202-2 perform demodulation processing, such as FFT, on the preamble signals input from the wireless receiving units 201-1 and 201-2, and extract control signals for demodulating and decoding data signals from the demodulated preamble signals. Furthermore, the preamble demodulation units 202-1 and 202-2 can perform channel estimation based on reference signals contained in the preamble signals. The preamble demodulation units 202-1 and 202-2 output the extracted control signals and channel estimation information (e.g., a channel estimation matrix) to the data decoding units 203-1 and 203-2.

[0112] Data decoding units 203-1 and 203-2, for example, perform FFT processing, channel equalization, or demodulation on the data input from the radio receiving units 201-1 and 201-2 based on control signals and channel estimation information input from the preamble demodulation units 202-1 and 202-2, and extract the demodulated data to be transmitted to the STA 200. Furthermore, data decoding units 203-1 and 203-2 decode the extracted demodulated data based on control signals input from the preamble demodulation units 202-1 and 202-2, thereby performing error detection such as CRC. For example, if the data signal is error-free, data decoding units 203-1 and 203-2 output the decoded data to the multi-link control unit 204. On the other hand, if the data signal contains errors, data decoding units 203-1 and 203-2 may not output decoded data.

[0113] The multi-link control unit 204 can, for example, determine the links used for multi-link feedback, or the method for allocating feedback information for the links, based on control information related to multi-link feedback contained in the decoded data input from the data decoding units 203-1 and 203-2. The multi-link control unit 204 outputs control information to the transmission signal generation unit 205, which includes information related to the determined links or information related to the method for allocating feedback information.

[0114] The transmit signal generation unit 205 generates a data sequence including feedback information based on control information input from the multi-link control unit 204. The transmit signal generation unit 205 allocates the generated data sequence to the respective frequency resources of each link and performs modulation and IFFT processing to generate a data signal (e.g., a transmit signal). Furthermore, for each link, the transmit signal generation unit 205 adds a preamble to the data signal to generate a radio frame (e.g., a packet signal) and outputs it to the radio transmission units 206-1 and 206-2 of each link. Additionally, "packet signal" can also be simply referred to as "packet".

[0115] The wireless transmission units 206-1 and 206-2 of each link perform wireless transmission processing such as D / A conversion and up-conversion to carrier frequency on the wireless frames input from the transmission signal generation unit 205, and transmit the processed signals to AP100 via antennas.

[0116] [Operating examples of AP100 and STA200]

[0117] Next, an example of the operation of AP100 and STA200 in this embodiment will be described.

[0118] Figure 11 This is a sequence diagram representing an example of the actions of a wireless communication system related to multi-link feedback transmission.

[0119] exist Figure 11 As an example, the following action example describes the transmission of feedback information between AP100, which has two links (e.g., link 1 and link 2), and STA200, which also has two links (e.g., link 1 and link 2). Furthermore, the number of links used to transmit feedback information can be "1" or more; in multi-link feedback, it is not limited to "2" and can also be "3" or more.

[0120] exist Figure 11 In this configuration, AP100 may, for example, send NDPA (S101-1, S101-2) containing control information related to multi-link feedback transmission to STA200 in each link (e.g., link 1 and link 2). STA200 may, for example, perform reception processing of the NDPA received in each link and obtain (or receive) the control information related to multi-link feedback (S102-1, S102-2). Alternatively, by sending NDPA, STA200 may be notified that NDP will be sent after (e.g., following NDPA).

[0121] AP100 can, for example, transmit NDP to STA200 (S103-1, S103-2). STA200 can, for example, perform NDP reception processing based on control information obtained from NDPA (S104-1, S104-2). For example, STA200 can perform channel estimation based on the reference signal (e.g., LTF) contained in the preamble of the received NDP.

[0122] exist Figure 11 For example, the STA200 can use the reference signal (e.g., LTF) contained in the preamble of the NDP transmitted in Link 1 to perform channel estimation for Link 1.

[0123] STA200 can generate feedback information (S105-1, S105-2), for example. For example, STA200 can generate one or more feedback information such as HE compressed beamforming report, HE MU exclusive beamforming report and HE CQI report based on the channel estimate obtained through channel estimation and the feedback type notified in the NDPA control information.

[0124] For example, STA200 can determine the link for sending feedback information (e.g., multi-link feedback transmission) based on the control information contained in NDPA, and send feedback information (S106-1, S106-2) to AP100 on the determined link. Figure 11 For example, STA200 can use Link 1 and Link 2 to send feedback information related to Link 1 to AP100.

[0125] AP100 can, for example, receive feedback information (S107-1, S107-2) sent from STA200 in each link. AP100 can, for example, reconstruct the feedback information allocated to each link based on the control information related to multi-link feedback contained in NDPA, or the control information contained in the feedback information.

[0126] For example, AP100 can send ACK signals (S108-1, S108-2) to STA200 in each link based on the results of receiving and processing the feedback information.

[0127] In addition, although Figure 11 The document describes the transmission of NDPA and NDP on links 1 and 2, but it is not limited to this; NDPA and NDP can also be transmitted on at least one of multiple links. Furthermore, although in Figure 11 The document describes the scenario where feedback information is generated related to link 1, but it is not limited to this; it could also generate feedback information related to at least one of multiple links. Furthermore, although in Figure 11The document describes the situation where feedback information is sent in two links, link 1 and link 2, but it is not limited to this. It is also possible that feedback information is sent in at least one of multiple links.

[0128] The above illustrates an example of the operation of a wireless communication system related to multi-link feedback transmission.

[0129] Next, examples of control methods for multi-link feedback transmission (control method 1 and control method 2) will be explained.

[0130] [Control Method 1]

[0131] In control method 1, the control information related to multi-link feedback transmission may include, for example, identification information of the links that can be used for multi-link transmission (e.g., referred to as "link identifier" or "link ID"). STA200 may, for example, determine the link among the multiple links to transmit feedback information based on the notified identification information.

[0132] For example, a link ID can be a bitmap where each bit corresponds to one of the links (e.g., called a "link ID bitmap"). For instance, a link with a link ID bitmap of 1 might be designated as a link for feedback transmission, and a link with a link ID bitmap of 0 might be designated as a link not for feedback transmission. Furthermore, link IDs are not limited to bitmap format and can be other forms of information.

[0133] For example, when STA200 is connected to AP100, the link ID can be set by AP100 (e.g., notified) to STA200.

[0134] In addition, the field length of the link ID bitmap can be either fixed or variable.

[0135] For example, such as Figure 12 As shown, the field length of the link ID bitmap can be set to a predefined (e.g., specified in the standard) maximum number of links. In other words, the amount of information in the link ID bitmap can be based on a predefined number of links. In this case, the field length of the link ID bitmap is fixed.

[0136] Additionally, for example, such as Figure 13 As shown, the field length of the Link ID bitmap can be set to the maximum number of links on AP100. In other words, the amount of information in the Link ID bitmap can be based on the number of links set for AP100. In this case, the field length of the Link ID bitmap is variable. For example, when connected to AP100, the maximum number of links based on the capabilities of AP100 can be notified to STA200 along with the Link ID.

[0137] For example, when the field length of the link ID bitmap is set to the maximum number of links of AP100, the link ID bitmap will be notified with a shorter field length compared to when the field length of the link ID bitmap is set to the maximum number of links determined by the standard. Therefore, signaling overhead can be reduced.

[0138] Additionally, for example, after receiving control information containing a link ID bitmap, the STA200 can determine, based on the link ID bitmap and the defined rules, which link to allocate for transmitting feedback information in multi-link transmission (in other words, the allocation of feedback information).

[0139] For example, the specified rules could be based on the number of spatial streams contained in the feedback information (e.g., the number of spatial streams whose reception quality is measured (or estimated)) and the bandwidth of each link used to send the feedback information. As an example, the number of spatial streams contained in the feedback information could be set to N, the number of links used for multi-link feedback as notified by the link ID bitmap could be set to two (e.g., link 1 and link 2), the bandwidth of link 1 could be set to BW1, and the bandwidth of link 2 could be set to BW2. In this example, the STA200 could send (N*BW1) / ((BW1+BW2)) feedback information in link 1 and (N*BW2) / ((BW1+BW2)) feedback information in link 2.

[0140] Additionally, the rules specified could be based on the type (or category) of feedback information. For example, if the number of links for multi-link feedback notified to the STA200 by the link ID bitmap is two (e.g., link 1 and link 2), the STA200 could send the average SNR of each spatial stream contained in the HE MU compressed beamforming report in link 1, and send the feedback matrix contained in the HE MU compressed beamforming report in link 2.

[0141] Furthermore, the type of feedback information transmitted in each link can be determined based on the frequency band of each link. For example, feedback information with a larger amount of information could correspond to the link with the higher frequency band among multiple links.

[0142] Alternatively, for example, higher priority (or importance) feedback information could correspond to a higher frequency band link among multiple links.

[0143] In this way, by notifying STA200 of the link ID bitmap from AP100, STA200 can perform multi-link feedback transmission.

[0144] Next, examples 1 to 4 will be given on the transmission of notification and feedback information of the link ID bitmap in control method 1.

[0145] <Example 1>

[0146] In Example 1, the STA200 may make the following decision: to use a link different from the link that received the control information (e.g., NDPA and NDP) for the transmission of feedback information in multi-link transmission.

[0147] Figure 14 This is a sequence diagram representing the action examples related to the transmission of control information and feedback information in Example 1.

[0148] exist Figure 14 For example, AP100 sends NDPA and NDP to STA200 in link 1. For example, in the link ID bitmap contained in NDPA, link 1 is set as a link not used for feedback transmission (link ID bitmap = 0), and link 2 is set as a link used for feedback transmission (link ID bitmap = 1) (for example, represented as "link ID bitmap =

[01] ").

[0149] exist Figure 14 For example, after receiving NDPA and NDP, STA200 sends feedback information related to link 1 (feedback(Link1)(feedback(Link1)) in link 2, which is different from link 1 that received the link ID bitmap (=

[01] ), based on the link ID bitmap contained in the NDPA of link 1.

[0150] Alternatively, the STA200 may acquire carrier sensing in Link 2 (in other words, the link not used for transmitting NDPA and NDP) (i.e., the channel state of Link 2 is idle) and send feedback information. For example, the STA200 may send feedback information after the Distributed Coordination Function (DCF) Inter-Frame Space (DIFS) and backoff time have elapsed.

[0151] According to Example 1, multi-link feedback can be implemented by separating the respective uses of multiple links. For example, a 2.4 GHz channel could be used as Link 1 for transmitting control information, and a 5 GHz channel could be used as Link 2 for high-speed data communication. By separating the use of links in this manner, frequency utilization efficiency in multi-link systems can be improved.

[0152] <Example 2>

[0153] In Example 2, the STA200 could synchronize the timing of feedback information transmission across multiple links. For example, feedback information could be transmitted simultaneously on multiple links.

[0154] Figure 15 This is a sequence diagram illustrating the actions related to the transmission of control information (e.g., NDPA and NDP) and feedback information in Example 2.

[0155] exist Figure 15 For example, AP100 sends NDPA and NDP to STA200 in Link 1 and Link 2.

[0156] For example, in the link ID bitmap contained in the NDPA of link 1, link 1 is set as the link used for feedback transmission (link ID bitmap = 1), and link 2 is set as the link used for feedback transmission (link ID bitmap = 1) (for example, represented as "link ID bitmap =

[11] "). Alternatively, in the link ID bitmap contained in the NDPA of link 2, link 1 is set as the link not used for feedback transmission (link ID bitmap = 0), and link 2 is set as the link used for feedback transmission (link ID bitmap = 1) (for example, represented as "link ID bitmap =

[01] ").

[0157] exist Figure 15 For example, after receiving NDPA and NDP, STA200 can send feedback information related to link 1 in link 1 and link 2 respectively (feedback (link 1)) based on the link ID bitmap contained in the NDPA of each link, and send feedback information related to link 2 in link 2 (feedback (link 2)). In other words, STA200 can send feedback information in both link 1 and link 2 simultaneously.

[0158] In addition, Figure 15 Since the STA200 receives NDPA and NDP in Link 1 and Link 2 respectively, it can send feedback information after the Short Inter-Frame Space (SIFS) of NDP. In other words, the STA200 can send feedback information in each link without acquiring carrier sensing.

[0159] According to Example 2, feedback information can also be distributed across multiple links based on their communication capacity. For example, in a multi-link feedback scenario where the communication capacity of link 2 is greater than that of link 1, the STA200 can transmit a portion of the feedback information from link 1 within link 2. By transmitting feedback information in this manner, frequency utilization efficiency across multiple links can be improved, thereby reducing feedback overhead.

[0160] <Example 3>

[0161] In Example 3, the STA200 could cause the timing of the feedback information transmission in multi-link transmission to differ between links.

[0162] Figure 16 This is a sequence diagram illustrating the actions related to the transmission of control information (e.g., NDPA and NDP) and feedback information in Example 3.

[0163] exist Figure 16 In the example, AP100 sends NDPA and NDP to STA200 in link 1. For example, in the link ID bitmap contained in the NDPA of link 1, link 1 is set as the link for feedback transmission (link ID bitmap = 1), and link 2 is set as the link for feedback transmission (link ID bitmap = 1) (for example, represented as "link ID bitmap =

[11] ").

[0164] exist Figure 16 For example, after receiving NDPA and NDP, STA200 sends feedback information (feedback (link 1)) related to link 1 in link 1 and link 2 respectively, based on the link ID bitmap (=[1,1]) contained in the NDPA of link 1.

[0165] In addition, Figure 16 In this context, because the STA200 receives NDPA and NDP in link 1, it can send feedback information in link 1 after receiving the SIFS of NDP. On the other hand, the STA200 can also acquire carrier sensing in link 2 (in other words, a link not used for transmitting NDPA and NDP) (i.e., when the channel state of link 2 is idle) and send feedback information. Therefore, as... Figure 16 As shown, for example, STA200 can send feedback information at different times on multiple links (e.g., link 1 and link 2).

[0166] At this time, as Figure 16 As shown, the timing of STA200 receiving the ACK signal from AP100 in link 1 and the timing of sending feedback information in link 2 may overlap. Therefore, STA200 may be a STR non-AP MLD.

[0167] exist Figure 16 In this scenario, feedback transmission in link 2 occurs later than in link 1. Therefore, for example, link 1 could be used to transmit high-priority feedback information, while link 2 could be used to transmit low-priority feedback information. This improves frequency utilization efficiency in multi-link feedback, thereby reducing feedback overhead.

[0168] <Example 4>

[0169] In Example 4, the STA200 could distribute the feedback information from multiple links in a multi-link transmission to a single link (or it could aggregate and transmit the information).

[0170] Figure 17 This is a sequence diagram representing the action examples related to the transmission of control information and feedback information in Example 4.

[0171] exist Figure 17 In the example, AP100 sends NDPA and NDP to STA200 in links 1 and 2. For example, in the link ID bitmaps contained in the NDPAs of links 1 and 2 respectively, link 1 is set as the link used for feedback transmission (link ID bitmap = 1), and link 2 is set as the link not used for feedback transmission (link ID bitmap = 0) (for example, represented as "link ID bitmap =

[10] ").

[0172] exist Figure 17 For example, after receiving NDPA and NDP, STA200 can send feedback information related to link 1 (feedback (link 1)) and feedback information related to link 2 (feedback (link 2)) in link 1 based on the link ID bitmaps of link 1 and link 2 respectively (=

[10] ). In other words, STA200 can aggregate the feedback information related to link 1 and link 2 respectively into link 1 and send it.

[0173] For example, with a common association ID (AID) for each link, the STA200 can use the A-MSDU (Aggregation MAC Service Data Unit) to aggregate feedback information from multiple links.

[0174] Alternatively, for example, during the period when STA200 is sending feedback information, AP100 may be on a link that is idle because STA200 aggregates feedback information to a single link. Figure 17 In link 2), packets are sent to other STA200s.

[0175] According to Example 4, for example, by aggregating feedback information to one link, frequency resources of other links can be freed up. Furthermore, the AP100 can, for example, transmit packets to other STAs using the freed frequency resources, thus improving frequency utilization efficiency. Additionally, by aggregating feedback information to one link, preamble overhead can be reduced, for example.

[0176] Furthermore, although Example 4 illustrates the case of aggregating feedback information into one of multiple links, it is not limited to this. Feedback information from multiple links can also be distributed to a subset of the links (e.g., two or more links).

[0177] The above examples illustrate the sending of notification and feedback information for the link ID bitmap in control method 1, namely Examples 1 to 4.

[0178] In control method 1, AP100, for example, notifies STA200 of control information related to multi-link transmission (e.g., a link ID bitmap). Then, STA200, for example, controls multi-link transmission (e.g., determines the links to send feedback information) based on the notified control information (e.g., the link ID bitmap).

[0179] This control can, for example, improve transmission efficiency in multi-link systems. For instance, the STA200 can determine which link to send feedback information based on the status or characteristics of each link.

[0180] [Control Method 2]

[0181] In control method 2, the control information related to multi-link feedback transmission may include, for example, information related to the allocation of feedback information for multiple links in multi-link transmission. STA200 may, for example, determine the allocation of feedback information between links in multi-link transmission based on the notified information related to the allocation of feedback information.

[0182] For example, the method for allocating feedback information can be based on parameters such as spatial stream, channel index (or frequency band), or type of feedback information.

[0183] <Use Case 1>

[0184] For example, AP100 and STA200 can determine the distribution of feedback information based on spatial streaming.

[0185] In this case, the control information related to multi-link feedback transmission may include, for example, information related to the spatial stream contained in the feedback information transmitted in each link. For example, such as... Figure 18 As shown, AP100 can notify STA200 of the starting index (e.g., Feedback SS start index) and the ending index (e.g., Feedback SS end index) of the spatial streams contained in the feedback information sent in each link.

[0186] As an example, 11be supports a maximum of 16 spatial streams; therefore, the feedback SS start index and feedback SS end index can each be set to 4-bit fields. Furthermore, the maximum number of supported spatial streams is not limited to 16; the number of bits for control information related to multi-link feedback transmission can be set according to the number of supported spatial streams.

[0187] <Use Case 2>

[0188] For example, AP100 and STA200 can determine the allocation of feedback information based on the channel index (frequency band).

[0189] In this case, the control information related to multi-link feedback transmission may include, for example, information related to the frequency band (e.g., channel) contained in the feedback information transmitted in each link. For example, such as Figure 19 As shown, AP100 can notify STA200 of the starting index (e.g., channel start index) and ending index (e.g., channel end index) of the channels (e.g., channels in 20MHz units) contained in the feedback information sent in each link.

[0190] As an example, channel indices can be allocated in ascending order, starting from the least significant 20MHz. Alternatively, for instance, 11be supports a maximum of 320MHz (20MHz * 16), so the channel start index and channel end index can each be set as 4-bit fields. Furthermore, the supported frequency band is not limited to a maximum of 320MHz; the number of bits for control information related to multi-link feedback transmission can be set according to the supported frequency band. Moreover, channel index allocation is not limited to ascending order starting from the least significant channel; it can also be done in descending order or according to other rules.

[0191] <Example 3>

[0192] For example, AP100 and STA200 can determine the allocation of feedback information based on the type of feedback information.

[0193] In this case, the control information related to multi-link feedback transmission may include information related to the types of feedback information transmitted in each link. For example, such as Figure 20 As shown, AP100 can notify STA200 of information indicating the type of feedback information sent in each link (e.g., feedback info type bit).

[0194] The above examples illustrate methods for distributing feedback information.

[0195] In control method 2, AP100, for example, notifies STA200 of control information related to multi-link transmission (e.g., information related to the allocation of feedback information). STA200 then, for example, controls multi-link transmission (e.g., determines the allocation of feedback information) based on the notified information related to the allocation of feedback information.

[0196] This processing can, for example, improve transmission efficiency in multi-link systems. For instance, the STA200 can appropriately distribute feedback information among multiple links based on the status of each link.

[0197] Furthermore, the allocation of feedback information is not limited to the parameters mentioned above; for example, it can also be based on other parameters corresponding to the status of each link.

[0198] Next, examples of the feedback information allocation methods in control method 2 (method 2-1 and method 2-2) will be explained.

[0199] [Method 2-1]

[0200] In method 2-1, for example, AP100 can determine the method for allocating feedback information for each link. In other words, STA200 can, for example, receive control information related to the allocation of feedback information from AP100, and based on the received control information, determine the allocation of feedback information sent to AP100 among the links in multi-link transmission.

[0201] AP100, for example, can... Figure 21 The control information related to the allocation of feedback information shown is included in the user information of the feedback request signal and is notified to STA200. Examples of feedback request signals include NDPA and trigger frames.

[0202] Figure 21 The "Feedback transmit link ID bitmap" shown can be, for example, the identifier of the link used for sending feedback. For instance, if there are two links used to send feedback information, the feedback transmit link ID bitmap can be represented by 2 bits, such as '10' for link 1, '01' for link 2, and '11' for both link 1 and link 2.

[0203] in addition, Figure 21 The "Feedback info link ID bitmap" shown can be, for example, information that informs the identifier of the link (e.g., the link whose reception quality is measured (or estimated)) contained in the feedback information. For example, if there are two links used to send the feedback information, the feedback info link ID bitmap can be represented by 2 bits, such as '10' for link 1, '01' for link 2, and '11' for both link 1 and link 2.

[0204] in addition, Figure 21The "Feedback SS Start Index" and "Feedback SS End Index" shown may, for example, be information related to the allocation of feedback information. Furthermore, although in Figure 21 The diagram illustrates a spatial stream-based allocation method (e.g., Figure 18 However, the information related to the allocation of feedback information is not limited to this; it can also be based on the aforementioned channel index (e.g., Figure 19 ) or the type of feedback information (e.g., Figure 20 The allocation method of ).

[0205] As an example, in the process of conducting such Figure 15 In the case of multi-link feedback transmission shown, AP100 can... Figure 22 The control information related to multi-link feedback shown is included in each link ( Figure 15 In the example of Link 1 and Link 2, the NDPA is used to notify STA200.

[0206] For example, in Figure 22 In the process, AP100 can notify STA200 to use link 1 in the user information of link 1 (e.g., feedback sending link ID bitmap = 10) and send feedback information related to spatial stream index 1 to spatial stream index 4 of link 1 (e.g., feedback information link ID bitmap = 10, feedback SS start index = 1 and feedback SS end index = 4).

[0207] Additionally, for example in Figure 22 In the process, AP100 can notify STA200 to use link 2 in the user information of link 2 (e.g., feedback sending link ID bitmap = 01), and send feedback information related to spatial stream index 5 to spatial stream index 8 of link 1 as well as feedback information related to link 2 (e.g., feedback information link ID bitmap = 11, feedback SS start index = 5 and feedback SS end index = 8).

[0208] For example, the STA200 can allocate feedback information and send feedback based on the control information contained in the user information received in Link 1 and Link 2 respectively.

[0209] Additionally, AP100 can, for example, reconstruct the feedback information sent from STA200 based on the feedback information allocation method. For example, in Figure 22 In this process, AP100 can reconstruct the feedback information of spatial stream 1 to spatial stream 8 of link 1 based on the feedback information received in link 1 related to spatial stream index 1 to spatial stream index 4 of link 1 and the feedback information received in link 2 related to spatial stream index 5 to spatial stream index 8 of link 1.

[0210] According to method 2-1, for example, AP100 can control the allocation of feedback information for each link based on the usage information (e.g., NAV status information) of each link of STA200, thus improving frequency utilization efficiency.

[0211] Next, examples 1 to 2 will be given on the notification of control information and the sending of feedback information in method 2-1.

[0212] <Example 1>

[0213] In Example 1, AP100 may include control information related to the feedback information of each link in the trigger frame and send it to STA200.

[0214] For example, in the case of multiple STA200 control (in other words, request) multi-link feedback, AP100 can include control information related to the feedback information in the User Info field of the trigger frame.

[0215] For example, such as Figure 23 As shown, control information related to feedback information can be included in the user information of the Beamforming Report Poll (BFRP) in the trigger frame.

[0216] Or, for example, such as Figure 24 As shown, control information related to feedback information may also be included in the trigger dependent user info of the trigger frame (e.g., BFRP).

[0217] Next, in Example 1, we will explain the action of AP100 in the case of multiple STA200 notifying multiple link feedback.

[0218] Figure 25 This is a sequence diagram illustrating the actions of AP100 in the case of multiple STA200 control multi-link feedback.

[0219] exist Figure 25 As an example, the operation of an AP100 (e.g., AP) with two links (e.g., link 1 and link 2) and two STA200s (e.g., STA1 and STA2) with two links are illustrated. Furthermore, as mentioned above, the number of links used for multi-link feedback can be "2" or more.

[0220] exist Figure 25 In this process, the AP sends NDPA and NDP (e.g., S201-1, S201-2, S204-1, and S204-2) to each STA in at least one of Link 1 and Link 2.

[0221] STA1 and STA2 perform NDPA reception processing in link 1 and link 2 respectively, and obtain control information for receiving NDP (e.g., S202-1, S202-2, S203-1 and S203-2).

[0222] Additionally, STA1 and STA2 perform NDP reception processing, for example (e.g., S205-1, S205-2, S206-1, and S206-2). Furthermore, STA1 and STA2 generate channel estimates and feedback information notified by control information obtained from NDPA (e.g., HE compressed beamforming report and HE MU exclusive beamforming report) (e.g., S207-1, S207-2, S208-1, and S208-2).

[0223] The AP, for example, sends a BFRP (e.g., a trigger frame) (e.g., S209-1 and S209-2) to STA1 and STA2. The BFRP may, for example, contain control information related to multi-link feedback transmission. Additionally, the BFRP may, for example, contain frequency resource allocation information for frequency reuse across links (e.g., also known as "OFDMA: Orthogonal Frequency-Division Multiple Accuses").

[0224] STA1 and STA2 perform BFRP reception processing and obtain control information and frequency resource allocation information related to multi-link feedback transmission (e.g., S210-1, S210-2, S211-1 and S211-2).

[0225] STA1 and STA2 can, for example, send feedback information to the AP based on control information notified by BFRP (e.g., S212-1, S212-2, S213-1, and S213-2). For instance, STA1 and STA2 can use allocated frequency resources to send feedback information to the AP via ULOFDMA. Additionally, for example, STA1 and STA2 can allocate feedback information to link 1 and link 2 based on control information related to multi-link feedback. Figure 25 In the example shown, STA1 distributes the feedback information corresponding to link 1 to both link 1 and link 2 for transmission. Additionally, in Figure 25 In the example shown, STA2 distributes the feedback information corresponding to link 2 to link 1 and link 2 for transmission.

[0226] The AP can, for example, receive and process feedback information sent from STA1 and STA2 respectively (e.g., S214-1 and S214-2). The AP can, for example, reconstruct the feedback information received from each STA in multiple links based on the control information notified to each STA.

[0227] In addition, based on the results of receiving and processing feedback information, the AP sends ACK signals to STA1 and STA2 (e.g., S215-1 and S215-2) in each link.

[0228] Thus, according to Example 1, AP100 can notify multiple STA200s of control information related to multi-link feedback at once. Furthermore, if control information is included in the BFRP trigger-dependent user information, signaling related to multi-link feedback can be omitted from the user information of different trigger frames than BFRP, thereby reducing feedback overhead.

[0229] <Example 2>

[0230] In Example 2, AP100 can, for example, include the control information of the feedback information of each link in the NDPA and send it to STA200.

[0231] For example, in the case of multi-link feedback to a single STA200 control (in other words, request), such as Figure 26 As shown, AP100 can include control information related to feedback information in the STA information (STA Info) of NDPA.

[0232] According to Example 2, AP100 can, for example, notify a single STA200 of control information related to multi-link feedback without triggering a frame (e.g., BFRP).

[0233] Furthermore, AP100 can also include control information related to multi-link feedback sent to multiple STAs in the NDPA. In this case, AP100 can, for example, use BFRP to notify each STA200 of the timing of feedback information transmission.

[0234] [Method 2-2]

[0235] In method 2-2, for example, STA200 can determine the method for allocating feedback information for each link. In other words, STA200 can, for example, determine the allocation of feedback information for multiple links and send control information related to the determined allocation of feedback information to AP100.

[0236] For example, the STA200 can... Figure 27The control information related to the allocation of feedback information is included in the feedback information and notified to AP100. Figure 27 For example, a "feedback information link ID bitmap" could be information that informs the identifier of the link contained in the feedback information (e.g., the link whose reception quality has been measured (or estimated)). Additionally, Figure 27 The "Feedback SS Start Index" and "Feedback SS End Index" shown may, for example, be information related to the allocation of feedback information. Furthermore, although in Figure 27 The diagram illustrates a spatial stream-based allocation method, but the information related to the allocation of feedback information is not limited to this; it can also be based on the aforementioned channel index (e.g., Figure 19 ) or the type of feedback information (e.g., Figure 20 The allocation method of ).

[0237] For example, such as Figure 28 As shown, control information related to the allocation of feedback information can be included in the HE MIMO control field of the compressed beamforming / CQI frame behavior field format. Furthermore, not limited to the HE MIMO control field, control information related to the allocation of feedback information can also be communicated to the AP100 in other fields.

[0238] As an example, in the process of conducting such Figure 15 In the case of multi-link feedback transmission shown, STA200 can notify AP100 that the feedback information of link 1 includes feedback information related to spatial stream indices 1 to 4 of link 1. Additionally, STA200 can, for example, notify AP100 that the feedback information of link 2 includes feedback information related to spatial stream indices 5 to 8 of link 1, as well as feedback information related to link 2.

[0239] Furthermore, for example, in such Figure 15 As shown in Link 2, when sending feedback information from multiple links within a single link, parameters common to the feedback information across multiple links can be specified in a single HE MIMO control field (e.g., ...). Figure 28 (Information such as "Nc" and "Nr" is different from control information related to multi-link feedback). Different HE MIMO control fields can be set for each link, and different feedback information parameters can be applied to each link.

[0240] According to method 2-2, for example, STA200 can autonomously control the allocation method of feedback information for each link based on the usage status of each link of STA200, thereby improving frequency utilization efficiency.

[0241] Furthermore, in the feedback information allocation method described in control method 2, feedback information can also be allocated to each link based on subcarrier index or frequency resource unit index.

[0242] Furthermore, although the example given in control method 2 is that BFRP is used as the trigger frame type when control information related to the transmission of feedback information is notified to STA200 using a trigger frame, control information related to multi-link feedback can also be notified to STA200 using a different trigger frame type than BFRP.

[0243] The above explains control method 1 and control method 2.

[0244] Furthermore, control method 1 (link ID notification) and control method 2 (feedback information allocation method notification) can be applied in combination or separately. For example, when control method 1 and control method 2 are combined, the allocation of feedback information set by control method 2 can be applied to multiple links used for feedback transmission as defined by control method 1. Alternatively, for example, when control method 2 is applied without applying control method 1, the allocation of feedback information set by control method 2 can be applied to multiple links defined for STA200.

[0245] The above describes various embodiments of this disclosure.

[0246] (Other implementation methods)

[0247] (1) Although the control methods 1 and 2 described above describe a situation where STA200 transmits feedback information containing information (e.g., reception quality) obtained from NDP (e.g., a reference signal contained in NDP) across multiple links, feedback information can also be obtained (or generated, estimated) based on a signal different from NDP. For example, STA200 can also transmit feedback information obtained from a reference signal contained in a packet different from NDP (e.g., called a "non-NDP PPDU") across multiple links, as described in Non-Patent Document 3's "interleaved detection".

[0248] Figure 29 This is a sequence diagram illustrating an example of actions taken by AP100 in the case of multi-link transmission of feedback information obtained from a non-NDP PPDU to STA200.

[0249] exist Figure 29As an example, this section illustrates the transmission of feedback information from two AP100 (e.g., AP) and two STA200s (e.g., STA1 and STA2). Furthermore, the number of links used for multi-link feedback can be "2" or more. Additionally, the number of STAs transmitting feedback information from non-NDP PPDUs via multiple links is not limited to two; it can also be three or more.

[0250] exist Figure 29 In this process, the AP, for example, sends NDPA containing control information related to feedback transmission to STA1 and STA2 in links 1 and 2 (S301). STA1 and STA2, for example, perform NDPA reception processing in links 1 and 2 respectively, and obtain the control information related to feedback transmission (S302).

[0251] The AP transmits NDP in Link 1 and Link 2, for example (S303). STA1 and STA2 perform NDP reception processing based on the control information obtained from NDPA (S304), and generate channel estimates and feedback information corresponding to Link 1 and Link 2, respectively (S305).

[0252] For example, the AP sends a trigger frame (S306). For instance, the AP can use a BFRP trigger frame to notify STA1 and STA2 of the control information (e.g., bandwidth, transmit power, allocated RU, MCS or allocated space stream, etc.) used to transmit feedback information in each link to the UL MU, as well as the timing of transmission.

[0253] STA1 and STA2, for example, perform trigger frame reception processing (S307). By receiving the trigger frame, STA1 and STA2 obtain control information for transmitting feedback information using UL MU-MIMO, and transmit feedback information (e.g., UL MU-MIMO signal) to the AP using UL MU-MIMO in Link 1 and Link 2 respectively at the transmission timing indicated by the trigger frame (S308).

[0254] The AP receives UL MU-MIMO signals transmitted from STA1 and STA2 respectively and obtains feedback information (S309). Based on the feedback information, the AP can, for example, schedule DL MU-MIMO transmissions and generate a steering matrix for each link. Additionally, the AP can, for example, perform null control on the steering matrix to reduce interference between STAs.

[0255] For example, the AP adds a steering matrix to the DL MU-MIMO signals (e.g., the reference signal and data section (DL MU PPDU) included in the preamble section) for STA1 and STA2 and transmits them (S310). Alternatively, the AP may, for example, retain the generated steering matrix in a buffer.

[0256] STA1 and STA2 perform, for example, reception processing of DL MU-MIMO signals (e.g., DL MU PPDU) (S311). For example, STA1 and STA2 can use the reference signal contained in the preamble of the DL MU-MIMO signal to perform channel estimation and extract the signal to the relevant STA. In addition, STA1 and STA2 can, for example, measure the reception quality of the reference signal to the relevant STA (e.g., the expected signal) and the reference signal to other STAs that are spatially multiplexed in the same RU as the relevant STA (e.g., the inter-user interference signal) based on the reference signal contained in the preamble of the DL MU-MIMO signal (in other words, the non-NDPPPDU).

[0257] In addition, as a measure of reception quality, examples include: the error determination result of the expected signal, the signal-to-interference-plus-noise ratio (SINR) of the expected signal, the power value of the inter-user interference signal, the ratio of the expected signal to the undesired signal (DUR) between the expected signal and the inter-user interference signal, the change in the expected signal power compared to the previous MU-MIMO signal, the change in the inter-user interference signal power, the change in the expected signal power between the NDP-detected expected signal power and the MU-MIMO signal, and the change in the inter-user interference signal power.

[0258] STA1 and STA2 can, for example, perform a threshold-based reception quality assessment of the expected signal and inter-user interference signal, and decide (or determine) the spatial stream for transmitting feedback information (S312). Furthermore, if the expected signal and inter-user interference signal comprise multiple spatial streams, STA1 and STA2 can, for example, perform a reception quality assessment of each spatial stream.

[0259] STA1 and STA2, for example, transmit a response signal (e.g., block ACK) for the DL MU-MIMO signal (S313). Additionally, if feedback information needs to be transmitted based on the reception quality determination of the expected signal and inter-user interference signals, each STA may include a signal requesting the transmission of a trigger frame (e.g., a trigger request) in its response signal; this trigger frame is the one that prompts the transmission of feedback information.

[0260] For example, when the AP receives a response signal containing a trigger request from STA1 and STA2, it schedules multi-link feedback, includes the control information related to multi-link feedback in the trigger frame of BFRP, and sends it to each STA (S314).

[0261] STA1 and STA2, for example, receive the trigger frame of BFRP and obtain control information related to multilink feedback transmission (S315). STA1 and STA2, for example, perform multilink feedback to the AP at the timing indicated by BFRP (S316). For example, in Figure 29 In the example shown, STA1 uses link 1 to send feedback information related to both link 1 and link 2 to the AP. Additionally, in Figure 29 In the example shown, STA2 uses link 2 to send feedback information related to link 1 and link 2 to the AP.

[0262] The AP, for example, receives feedback information sent from the STA (S317). The AP can, for example, reconstruct the feedback information transmitted from multiple links based on the control information related to multi-link feedback contained in the BFRP, or the control information contained in the feedback information. Additionally, the AP can, for example, determine which STA's spatial stream the feedback information is related to based on the control information contained in the feedback information. The AP can, for example, update the redirection matrix stored in the buffer based on newly acquired feedback information and save it back to the buffer. Furthermore, the AP can, for example, change the DLMU-MIMO transmission schedule (e.g., RU allocation or user allocation) based on the feedback information sent from STA1 and STA2. Additionally, the AP can, for example, send an ACK signal in each link according to the result of the feedback information reception processing (S318).

[0263] In addition, although Figure 29 The example described is that each STA transmits feedback information obtained from DL MU-MIMO signals sent to two STAs (in other words, non-NDP PPDUs) via multiple links, but it is not limited to this. For example, feedback information obtained from DL SU signals sent to a single STA can also be transmitted via multiple links, as in the case of interleaved detection.

[0264] (2) AP100 can also coordinate with multiple APs (e.g., referred to as "multi-AP") to send multi-link instructions for feedback information for each AP to STA200.

[0265] Figure 30 This is a sequence diagram of actions taken when AP100 sends notifications (or instructions) to STA200 regarding feedback information related to multiple APs across multiple links.

[0266] exist Figure 30 As an example, this section illustrates the action of sending feedback information in two AP100s (e.g., AP1 and AP2) with two links (e.g., link 1 and link 2) and one STA200 (e.g., STA1).

[0267] Furthermore, the number of links used for multi-link feedback can be two or more. Additionally, the number of APs coordinating with multiple APs is not limited to two; it can be three or more. Furthermore, the number of STAs notifying multiple APs of feedback information via multiple links is not limited to one; it can be two or more.

[0268] exist Figure 30 In this process, AP1, which controls the transmission of multiple APs, sends a multi-AP trigger (S401) to AP2, which is coordinating the transmission with AP1. This multi-AP trigger can be used to notify AP2 of control information related to coordinated transmission with NDPA and NDP (e.g., information indicating whether to notify of multi-link feedback, transmission timing, or transmission power information).

[0269] AP1 and AP2, for example, send NDPA and NDP (referred to as "Joint sounding") containing control information related to multi-link feedback at the time when AP1 notifies AP2 by utilizing multiple APs (e.g., S402 and S404).

[0270] STA1, for example, performs NDPA reception processing on both Link 1 and Link 2, and obtains control information related to multi-link transmission of feedback information (S402). Additionally, STA1, for example, performs NDPA reception processing on both Link 1 and Link 2 (S405), and generates channel estimates and feedback information for each AP (S406). Furthermore, STA1, for example, determines the link used to transmit feedback information based on the control information contained in the NDPA, and transmits feedback information to each AP (S407). Figure 30 In the example shown, STA1 sends feedback information of AP1's Link 1 and Link 2 in Link 1, and sends feedback information of AP2's Link 1 and Link 2 in Link 2.

[0271] AP1 and AP2, for example, receive feedback information in link 1 or link 2 (S408), and send an ACK signal to STA1 based on the result of receiving and processing the feedback information (S409). AP1 and AP2 can send an ACK signal in the link where feedback information has been received, for example.

[0272] (3) In control method 1 (notification of link ID), AP100 may, for example, use other methods different from the transmission of link ID to send link notification for feedback to STA200.

[0273] As an example, the link used for feedback transmission can be notified to the STA200 based on a combination of frequency band (e.g., bandwidth (BW) or channel (BW)) and channel identifier (e.g., channel ID).

[0274] For example, such as Figure 31 As shown, AP100 can notify STA200 of the frequency band in the BW field and the channel identifier in the channel ID field. For example, as Figure 32 As shown, the frequency band used by the STA200 can be specified in the BW field (e.g., one of 2.4GHz, 5GHz, and 6GHz). Additionally, for example, as... Figure 32 As shown, the following channel IDs can be notified in the channel ID field, and these channel IDs are assigned to the various frequency bands notified in the BW field in ascending order (in... Figure 32 The channel number (ch) that can be used, for example, 2.4GHz, 5GHz, 6GHz.

[0275] The STA200 can, for example, determine the link (e.g., channel) used for feedback transmission based on a combination of frequency band and channel ID notified by the AP100. For example, in... Figure 32 In the case of BW=01 (5GHz) and channel ID=0001, STA200 can determine 40ch corresponding to the combination of BW=01 and channel ID=0001 as the link for feedback transmission.

[0276] also, Figure 32 The values ​​or number of bits for the frequency band and channel ID shown are examples, but other values ​​or number of bits are also possible.

[0277] As another example, the link used for feedback transmission may be notified to the STA200 based on a combination of a frequency band (e.g., BW) and an offset value (e.g., channel offset) relative to the frequency of one of the multiple links (e.g., link 1).

[0278] For example, such as Figure 33 As shown, AP100 can notify STA200 of the frequency band in the BW field and notify STA200 of the coefficient for the offset value in the channel offset field. This offset value is based on the frequency difference between the center frequency of other links and the center frequency of link 1.

[0279] Here, for example, such as Figure 34 As shown, for each frequency band notified to STA200, the frequency difference (e.g., ΔChannel frequency) between adjacent channels is determined. For example, in the 2.4GHz band, if the center frequency difference between Link 1 and Link 2 is 40MHz, the frequency offset value, as the product of the channel frequency difference ΔChannel frequency and a coefficient, is expressed as 40MHz = 5MHz * 8. Therefore, AP100 can, for example, notify STA200 of BW = 00 (2.4GHz) and channel offset = 1000 (e.g., 8).

[0280] also, Figure 34 The values ​​or number of bits for the frequency bands and channel differences shown are examples, but other values ​​or number of bits are also possible. Furthermore, the control information notified by AP100 to STA200 is not limited to the above coefficients; any information or parameter representing the frequency difference between the center frequency of other links and the center frequency of link 1 is acceptable.

[0281] (4) The information transmitted by multiple links is not limited to feedback information.

[0282] For example, the STA200 can also transmit response signals (e.g., ACK, BA) or link adaptation signals across multiple links.

[0283] (5) Although the above embodiments illustrate a structural example based on the 11ax frame format, the format of an embodiment of the present disclosure is not limited to the 11ax format.

[0284] (6) Although the actions in DL communication have been described in the above embodiments, they are not limited to DL communication. An embodiment of this disclosure may be applied to UL communication or side link, for example.

[0285] (7) This disclosure can be implemented in software, hardware, or software in cooperation with hardware. The functional blocks used in the above embodiments are implemented partially or entirely as LSIs (Large Scale Integrations) of integrated circuits, and the processes described in the above embodiments can also be controlled partially or entirely by a single LSI or a combination of LSIs. An LSI can be composed of individual chips, or it can be composed of a single chip containing some or all of the functional blocks. An LSI can also include data input and output. Depending on the degree of integration, an LSI can also be called an "IC (Integrated Circuit)," a "System LSI," a "Super LSI," or an "Ultra LSI."

[0286] The method of integrating LSIs is not limited to LSIs; it can also be implemented using dedicated circuits, general-purpose processors, or special-purpose processors. Alternatively, LSIs can be used to fabricate programmable FPGAs (Field Programmable Gate Arrays), or reconfigurable processors that allow for reconfiguration of the connections or settings of the circuit blocks within the LSI. This disclosure can also be implemented for digital or analog processing.

[0287] Furthermore, if advancements in semiconductor technology or the emergence of other derivative technologies lead to integrated circuit technologies that can replace LSIs, these technologies could also be used to integrate functional blocks. There are also possibilities for applications such as biotechnology.

[0288] This disclosure can be implemented in all kinds of devices, apparatuses, and systems with communication capabilities (collectively referred to as "communication devices"). A communication device may also include a wireless transceiver and processing / control circuitry. The wireless transceiver may also include a receiving unit and a transmitting unit, or perform the functions of these units. The wireless transceiver (transmitting unit, receiving unit) may also include an RF (Radio Frequency) module and one or more antennas. The RF module may also include an amplifier, an RF modulator / demodulator, or similar devices. Non-limiting examples of communication devices include: telephones (mobile phones, smartphones, etc.), tablet computers, personal computers (PCs) (laptops, desktops, laptops, etc.), cameras (digital cameras, digital camcorders, etc.), digital players (digital audio / video players, etc.), wearable devices (wearable cameras, smartwatches, tracking devices, etc.), game consoles, e-book readers, remote health / telemedicine (remote healthcare / medical prescription) devices, vehicles or transportation vehicles with communication capabilities (cars, airplanes, ships, etc.), and combinations of the various devices described above.

[0289] Communication devices are not limited to portable or mobile devices, but also include all kinds of devices, equipment, and systems that cannot be carried or fixed. Examples include smart home devices (home appliances, lighting equipment, smart meters or meters, control panels, etc.), vending machines, and all other "things" that can exist on the IoT (Internet of Things) network.

[0290] In addition to data communication via cellular systems, wireless LAN (Local Area Network) systems, and communication satellite systems, communication also includes data communication via a combination of these systems.

[0291] In addition, the communication device also includes devices such as controllers or sensors that are connected or linked to the communication equipment performing the communication functions described in this invention. For example, it includes controllers or sensors that generate control signals or data signals used by the communication equipment performing the communication functions of the communication device.

[0292] In addition, the communication device includes infrastructure equipment that communicates with or controls the various devices described above (not limited to these), such as base stations, access points, and all other devices, equipment, and systems.

[0293] One embodiment of the communication apparatus disclosed herein includes: a control circuit that controls the multi-link transmission based on control information related to multi-link transmission; and a transmission circuit that performs the multi-link transmission according to the control of the multi-link transmission.

[0294] In one embodiment of this disclosure, the control information includes identification information of links that can be used for transmission in the multi-link system, and the control circuit determines, based on the identification information, the link in the multi-link system used to transmit feedback information.

[0295] In one embodiment of this disclosure, the amount of information in the identification information is based on either a predefined number of links or a set number of links for the access point.

[0296] In one embodiment of this disclosure, the control circuit determines, based on predefined rules, which link to allocate for transmitting the feedback information in the multi-link transmission.

[0297] In one embodiment of this disclosure, the rules are based on the number of spatial streams contained in the feedback information and the bandwidth of each link used to send the feedback information.

[0298] In one embodiment of this disclosure, the rule is a rule based on the type of feedback information.

[0299] In one embodiment of this disclosure, the control circuit determines to use a link different from the link that received the control information for transmitting feedback information in the multi-link transmission.

[0300] In one embodiment of this disclosure, the control circuit synchronizes the timing of the transmission of feedback information in the multi-link transmission between links.

[0301] In one embodiment of this disclosure, the control circuit causes the timing of the transmission of feedback information in the multi-link transmission to differ between links.

[0302] In one embodiment of this disclosure, the control circuit distributes the feedback information of each of the multiple links to a subset of the links during the multi-link transmission.

[0303] In one embodiment of this disclosure, the control information includes information related to the allocation of feedback information for multiple links in the multi-link transmission, and the control circuit determines the allocation of the feedback information between links in the multi-link transmission based on the allocation-related information.

[0304] In one embodiment of this disclosure, the control information includes information related to the spatial stream contained in the feedback information sent in each link.

[0305] In one embodiment of this disclosure, the control information includes information related to the frequency band contained in the feedback information transmitted in each link.

[0306] In one embodiment of this disclosure, the control information includes information related to the type of feedback information sent in each link.

[0307] In one embodiment of this disclosure, a receiving circuit is further included to receive the control information from the access point. The control circuit determines, based on the control information, the allocation of feedback information to the access point among the links in the multi-link transmission.

[0308] In one embodiment of this disclosure, the control information is contained in a trigger frame.

[0309] In one embodiment of this disclosure, the control information is included in a trigger-dependent user information field.

[0310] In one embodiment of this disclosure, the control information is included in Null Data Packet Advertisement (NDPA).

[0311] In one embodiment of this disclosure, the transmitting circuit uses the feedback information to send information related to the inter-link allocation in the multi-link transmission of feedback information to the access point.

[0312] One embodiment of the communication apparatus disclosed herein includes: a control circuit that controls the reception of the multi-link transmission performed by the other communication apparatus based on control information related to multi-link transmission; and a receiving circuit that, according to the control of the reception, performs the reception of the multi-link transmission performed by the other communication apparatus.

[0313] In a communication method according to one embodiment of this disclosure, the communication device controls the multi-link transmission based on control information related to multi-link transmission, and performs the multi-link transmission according to the control of the multi-link transmission.

[0314] In a communication method according to one embodiment of this disclosure, a communication device controls the reception of multi-link transmissions performed by the other communication device based on control information related to multi-link transmissions, and performs the reception of multi-link transmissions performed by the other communication device according to the control of the reception.

[0315] The entire contents of the specification, drawings and abstract of the specification contained in Japanese Patent Application No. 2020-143901, filed on August 27, 2020, are incorporated herein by reference.

[0316] Industrial applicability

[0317] One embodiment of this disclosure is useful for wireless communication systems.

[0318] Explanation of reference numerals in the attached figures

[0319] 100 AP

[0320] Wireless receiving units 101-1, 101-2, 201-1, 201-2

[0321] 102 Receiver Signal Decoding Unit

[0322] 103 Feedback Information Reconstruction Department

[0323] 104 Multi-link Scheduling Department

[0324] 105 Data Generation Department

[0325] 106 Preamble Generation Unit

[0326] Wireless Transmission Units 107-1, 107-2, 206-1, 206-2

[0327] 200 STA

[0328] 202-1 and 202-2 preamble demodulation units

[0329] Data Decoding Department 203-1, 203-2

[0330] 204 Multi-link Control Unit

[0331] 205 Signal Generation Unit

Claims

1. A non-access point multi-link device (non-AP MLD), comprising a non-AP MLD having multiple auxiliary STAs corresponding to multiple links, including: The receiving circuit receives a first signal on a first link and a second signal on a second link, and performs channel estimation for the first link and channel estimation for the second link. The control circuit controls the multi-link transmission based on control information related to multi-link transmission containing feedback information including channel estimation results of the first link and the second link; as well as The transmitting circuit, according to the multi-link transmission control, transmits the feedback information on one or more links. The control information includes identification information of the links that can be used for transmission via the multi-link system. Based on the identification information, the control circuit determines one or more links from among the plurality of links that are used in the transmission of the feedback information. The control circuit determines the allocation of feedback information for the one or more links based on the identification information. The transmitting circuit sends the feedback information based on the allocation.

2. The non-AP MLD as described in claim 1, wherein, The amount of information in the identification information is based on either the number of links predefined or the number of links set for the access point multi-link device (AP MLD).

3. The non-AP MLD as described in claim 1, wherein, The control circuit determines, based on predefined rules, which link to allocate the transmission of the feedback information in the multi-link transmission.

4. The non-AP MLD as described in claim 3, wherein, The rules are based on the number of spatial streams contained in the feedback information and the bandwidth of each of the one or more links used to send the feedback information.

5. The non-AP MLD as described in claim 3, wherein, The rules are based on the types of feedback information.

6. The non-AP MLD as described in claim 1, wherein, The control circuit decides to use a link different from the link that received the control information for sending the feedback information.

7. The non-AP MLD as described in claim 1, wherein, The control circuit synchronizes the timing of the feedback information transmission across links.

8. The non-AP MLD as described in claim 1, wherein, The control circuit causes the timing of the feedback information transmission to differ between links.

9. The non-AP MLD as described in claim 1, wherein, The control circuit distributes the feedback information of each of the multiple links to a portion of the links.

10. The non-AP MLD as described in claim 1, wherein, The control information includes information related to the allocation of feedback information for the plurality of links. The control circuit determines the allocation of feedback information between links in the multi-link transmission based on information related to the allocation.

11. The non-AP MLD as described in claim 10, wherein, The control information includes information related to the spatial stream contained in the feedback information sent in each link.

12. The non-AP MLD as described in claim 10, wherein, The control information includes information related to the frequency band contained in the feedback information transmitted in each link.

13. The non-AP MLD as described in claim 10, wherein, The control information includes information related to the type of feedback information sent in each link.

14. An access point multi-link device (AP MLD), comprising an APMLD having multiple auxiliary STAs corresponding to multiple links, including: The transmitting unit transmits a first signal on the first link and a second signal on the second link. The control circuit controls the reception of the multi-link transmission performed by the non-AP MLD based on control information related to the multi-link transmission, which includes feedback information of the channel estimation results of the first link and the second link performed by the non-access point multi-link device (non-AP MLD). as well as The receiving circuit, according to the control of the received signal, receives the feedback information on one or more links. The control information includes identification information of the links that can be used for transmission via the multi-link system. Based on the identification information, the control circuit determines one or more of the multiple links used in receiving the feedback information. The allocation of feedback information for one or more links is determined based on the identification information. The receiving circuit receives the feedback information sent based on the allocation.

15. A communication method, wherein, A non-access point multi-link device (non-AP MLD) with multiple affiliated STAs corresponding to multiple links performs the following operations: A first signal is received on a first link, a second signal is received on a second link, and channel estimation is performed for the first link and the second link. Control information related to multi-link transmission, including feedback information containing channel estimation results from the first and second links, is used to control the multi-link transmission. According to the multi-link transmission control, the feedback information is transmitted on one or more links. The control information includes identification information of the links that can be used for transmission via the multi-link system. Based on the identification information, one or more links among the plurality of links used in the transmission of the feedback information are determined. Based on the identification information, the allocation of feedback information for the one or more links is determined. Based on the allocation, the feedback information is sent.

16. A communication method, wherein, The Access Point Multilink Device (APMLD), which has multiple affiliated STAs corresponding to multiple links, performs the following operations: Send the first signal on the first link, and send the second signal on the second link. Control information related to multi-link transmission, including feedback information on channel estimation results for the first and second links performed by the non-AP MLD, controls the reception of the multi-link transmission performed by the non-AP MLD. Based on the received control, the feedback information is received on one or more links. The control information includes identification information of the links that can be used for transmission via the multi-link system. Based on the identification information, one or more links among the plurality of links used in receiving the feedback information are determined. The allocation of feedback information for one or more links is determined based on the identification information. Receive the feedback information sent based on the allocation.

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