Feedback method and apparatus

Abstract

To provide a feedback method and device for improving accuracy of channel measurement.SOLUTION: In a wireless communication system, a method includes receiving, by a first communication device, a first physical layer protocol data unit (PPDU). The first PPDU includes information indicating channel fluctuation. The method also includes determining, by the first communication device, whether to trigger the second communication device to transmit the feedback result based on whether the channel fluctuation exceeds a specified fluctuation threshold.SELECTED DRAWING: Figure 7

Description

[Technical Field]

[0001] The present application relates to the field of wireless communication technologies, and in particular to a feedback method and apparatus. [Background technology]

[0002] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims priority to Chinese Patent Application No. 202110653974.X, entitled "FEEDBACK METHOD, AND APPARATUS," filed with the State Intellectual Property Office of China on June 11, 2021, which is incorporated herein by reference in its entirety.

[0003] During channel measurement, in the measurement phase, a sensing transmitter sends a null data packet announcement (NDPA) and a null data packet (NDP) to instruct one or more sensing receivers to perform channel measurements. In the reporting phase, the sensing transmitter requests feedback of channel variations, and the sensing receivers transmit information about whether the channel variations meet a predetermined condition. The sensing transmitter triggers sensing receivers whose channel variations meet the predetermined condition to feed back the channel measurement results. In response, the sensing receivers feed back the channel measurement results.

[0004] In the channel measurement and feedback procedure, the sensing receiver only feeds back the result of whether the channel fluctuation meets the predetermined condition, so the reliability of the feedback of the result of whether the channel fluctuation meets the predetermined condition is low. As a result, the sensing transmitter cannot accurately determine whether to trigger the feedback result, which reduces the accuracy of the channel measurement. Summary of the Invention

[0005] The present application provides a feedback method and apparatus to improve the accuracy of channel measurements.

[0006] According to a first aspect, a feedback method is provided. The method may be implemented by an interaction between a first communication device and a second communication device. The first communication device may be an access point (AP), and the second communication device may be a station (STA). This is merely an illustrative example herein, and the specific types of the first communication device and the second communication device are not particularly limited.

[0007] The first communication device receives a first physical protocol data unit (PPDU), where the first PPDU includes first information, which includes at least one of the following types of information: channel state information (CSI) measurement quantity indication information required for channel variation calculation, CSI type for channel variation calculation, information on a rule for channel variation calculation, or a feedback suggestion parameter, where the feedback suggestion parameter indicates a suggested feedback form. It can be understood that in this step, the first communication device may receive one or more first PPDUs transmitted by one or more second communication devices. The first information in the first PPDUs transmitted by these second communication devices may be the same or different. The first information is used to determine whether to trigger the second communication device to transmit a feedback result.

[0008] The first communication device may determine whether to trigger the second communication device to transmit a feedback result based on the first information. In this specification, the first communication device may selectively trigger the second communication device to transmit the first PPDU based on the first information. That is, the first communication device selects the second communication device to transmit the feedback result. In other words, in the solution provided in this specification, the first communication device no longer determines whether to trigger the second communication device to feedback a result based only on whether the channel variation calculated by the second communication device satisfies a predetermined condition, but further determines whether the second communication device should transmit the feedback result based on the first information and selects the second communication device to transmit the feedback result, thereby improving the accuracy of the decision. In this specification, the second communication device whose calculated channel variation satisfies the predetermined condition may be triggered, but the second communication device whose calculated channel variation does not satisfy the predetermined condition may also be triggered. This is not limited in this specification.

[0009] Furthermore, when the first communication device determines to trigger the second communication device to send the feedback result, the first communication device may send a third PPDU, where the third PPDU is used to trigger the second communication device to send the feedback result.

[0010] The first communication device may further receive a feedback result, which is transmitted by the triggered second communication device.

[0011] In this method, the first information is used to select the second communication device to which the feedback result is to be sent. Compared to when triggering the second communication device is determined solely based on whether the channel fluctuation satisfies a predetermined condition, the first communication device can more accurately determine the one or more second communication devices to be triggered based on the received first information, and the triggered one or more second communication devices will send the feedback result. In this way, the accuracy of channel measurement can be improved.

[0012] In a possible design, whether the channel variation satisfies the predetermined condition may be determined based on whether the channel variation exceeds a specified variation threshold. For example, if the channel variation exceeds the specified variation threshold, the channel variation is determined to satisfy the predetermined condition, and if the channel variation does not exceed the specified variation threshold, the channel variation is determined not to satisfy the predetermined condition.

[0013] In a possible design, the first PPDU may further include second information, where the second information indicates whether the channel fluctuation exceeds a specified fluctuation threshold.

[0014] Optionally, the first communication device may select a second communication device to transmit the feedback result to based on the first information and the second information. For example, the first communication device may first determine second communication devices whose channel fluctuation exceeds a specified fluctuation threshold, and then further select from those second communication devices a second communication device to transmit the feedback result to based on the first information. In another example, the first communication device may first determine second communication devices whose channel fluctuation does not exceed a specified fluctuation threshold, and then further select from those second communication devices a second communication device to transmit the feedback result to based on the first information.

[0015] Optionally, the first PPDU may carry a feedback response frame, where the feedback response frame includes a result indicating whether the channel fluctuation exceeds a specified fluctuation threshold.

[0016] When the second communication device transmits the first PPDU to the first communication device under the command of the first communication device, in a possible design, the first communication device may further transmit a second PPDU, where the second PPDU includes third information, which is used to request or notify the first information. In this specification, the third information in the second PPDU indicates which information is to be fed back by the second communication device, thereby improving the flexibility of the feedback.

[0017] In a possible design, the third information includes at least one of the following types: CSI measurement quantity indication information required for channel variation calculation, CSI type for channel variation calculation, information on a rule for channel variation calculation, feedback suggestion parameters, or indication information for clearing CSI.

[0018] If the third information is used to request the first information and the third information includes CSI measurement quantity indication information necessary for channel variation calculation, it indicates that the third information is used to request the second communication device to feed back the CSI measurement quantity indication information necessary for channel variation calculation.

[0019] If the third information is used to request the first information and the third information includes a CSI type for channel variation calculation, it indicates that the third information is used to request the second communication device to feed back the CSI type for channel variation calculation.

[0020] If the third information is used to request the first information and the third information includes information about the rule of channel variation calculation, it indicates that the third information is used to request the second communication device to feed back information about the rule of channel variation calculation.

[0021] If the third information is used to request the first information and the third information includes a feedback suggestion parameter, it indicates that the third information is used to request the second communication device to feed back the feedback suggestion parameter.

[0022] If the third information is used to notify the first information and the third information includes CSI measurement quantity indication information necessary for channel variation calculation, it indicates that the third information is used to notify the second communication device to calculate channel variation based on the quantity indicated by the CSI measurement quantity indication information.

[0023] If the third information is used to notify the first information and the third information includes a CSI type for channel variation calculation, it indicates that the third information is used to notify the second communication device to calculate channel variation using that CSI type.

[0024] If the third information is used to notify the first information and the third information includes information about a rule for channel variation calculation, it indicates that the third information is used to notify the second communication device to calculate the channel variation according to the rule.

[0025] When the third information is used to notify the first information and the third information includes a feedback suggestion parameter, it indicates that the third information is used to notify the second communication device to feed back the feedback suggestion parameter.

[0026] If the third information is used to signal the first information and the third information includes indication information for clearing CSI, the third information is used to signal the second communication device to clear the stored CSI.

[0027] It should be noted that the above are merely examples. If the third information includes multiple types of information among CSI measurement quantity indication information required for channel variation calculation, CSI type for channel variation calculation, information on the rule for channel variation calculation, feedback suggestion parameters, and indication information for clearing CSI, the corresponding meaning of the third information can be obtained based on the meaning of the information shown in the above examples. Details will not be repeated in this specification.

[0028] In a possible design, the CSI measurement quantity indication information required for channel variation calculation includes at least one of the following types: an indication information indicating whether more measurements are needed, a total number of measurements, or a remaining number of measurements.

[0029] In a possible design, the CSI type for channel variation calculation includes at least one of the following types: currently measured CSI, CSI whose measurement time exceeds a specified time threshold, CSI whose measurement quantity exceeds a specified quantity threshold, previously measured CSI, first measured CSI, average CSI, numbered CSI, or flagged CSI.

[0030] In a possible design, the feedback suggestion parameter may include at least one of the following types: a feedback type, a number of subcarriers in a subcarrier group, a number of bits of codebook information, or a number of bits of CSI.

[0031] In a possible design, the first information is carried in a media access control (MAC) frame of the first PPDU, i.e., the data field of the first PPDU includes a MAC frame and the MAC frame includes the first information, or the first information is carried in a physical layer (PHY) preamble of the first PPDU.

[0032] According to a second aspect, a feedback method is provided. The method may be implemented by an interaction between a first communication device and a second communication device. The first communication device may be an AP, and the second communication device may be a STA. This is merely an illustrative example, and the specific types of the first communication device and the second communication device are not particularly limited.

[0033] The second communication device may generate a first PPDU, where the first PPDU includes first information, and the first information includes at least one of the following types of information: CSI measurement quantity indication information required for channel variation calculation, CSI type for channel variation calculation, information about a rule for channel variation calculation, or a feedback suggestion parameter, where the feedback suggestion parameter indicates a suggested feedback form.

[0034] The second communication device transmits the first PPDU.

[0035] In this step, the second communication device may actively transmit the first PPDU to the first communication device, or may transmit the first PPDU to the first communication device under the command of the first communication device.

[0036] The second communication device that transmits the first PPDU may be triggered to feedback or may not be triggered to feedback. Optionally, the second communication device may receive a third PPDU, where the third PPDU is used to trigger the second communication device to transmit a feedback result.

[0037] The second communication device may determine that the second communication device is triggered, and the triggered second communication device may transmit a feedback result.

[0038] In a possible design, the first PPDU may further include second information, where the second information indicates whether the channel fluctuation exceeds a specified fluctuation threshold.

[0039] When the second communication device transmits a first PPDU to the first communication device under the command of the first communication device, in a possible design, the second communication device may further receive a second PPDU, where the second PPDU includes third information, and the third information is used to request the first information or notify the first information.

[0040] In a possible design, the third information includes at least one of the following types: CSI measurement quantity indication information required for channel variation calculation, CSI type for channel variation calculation, information on a rule for channel variation calculation, feedback suggestion parameters, or indication information for clearing CSI.

[0041] In a possible design, the CSI measurement quantity indication information required for channel variation calculation includes at least one of the following types: an indication information indicating whether more measurements are needed, a total number of measurements, or a remaining number of measurements.

[0042] In a possible design, the CSI type for channel variation calculation includes at least one of the following types: currently measured CSI, CSI whose measurement time exceeds a specified time threshold, CSI whose measurement quantity exceeds a specified quantity threshold, previously measured CSI, first measured CSI, average CSI, numbered CSI, or flagged CSI.

[0043] In a possible design, the feedback suggestion parameter may include at least one of the following types: a feedback type, a number of subcarriers in a subcarrier group, a number of bits of codebook information, or a number of bits of CSI.

[0044] In a possible design, the first information may be carried in a MAC frame of the first PPDU, or the first information may be carried in a PHY preamble of the first PPDU.

[0045] According to a third aspect, a feedback method is provided. The method may be implemented by an interaction between a first communication device and a second communication device. The first communication device may be an AP, and the second communication device may be a STA. This is merely an illustrative example, and the specific types of the first communication device and the second communication device are not particularly limited.

[0046] The first communication device generates a second PPDU, where the second PPDU includes third information, which is used to request or notify the first information. The third information includes, but is not limited to, at least one of the following types of information: CSI measurement quantity indication information required for channel variation calculation, CSI type for channel variation calculation, information on a rule for channel variation calculation, feedback suggestion parameters, or indication information for clearing CSI.

[0047] The first communication device transmits a second PPDU. The third information is used to request the first information. For example, if the third information includes a CSI type for channel variation calculation, it indicates that the second communication device is requested to feedback whether a specific type of CSI participates in the process of calculating channel variation. In this way, the first communication device can selectively trigger the second communication device to transmit the first information based on the first information fed back by the second communication device, thereby improving the accuracy of the decision.

[0048] The third information is used to notify the first information. For example, if the third information includes a CSI type for channel variation calculation, it indicates that the second communication device is notified to participate in the process of calculating channel variation using a specific type of CSI. This is equivalent to informing the second communication device to calculate input parameters for channel variation calculation, thereby further influencing the channel variation calculated by the second communication device. The first communication device can more accurately determine whether to trigger the second communication device to transmit a feedback result when channel variation occurs.

[0049] Based on the above technical solutions, the first information that needs to be fed back by the second communication device is requested, or the second communication device is notified of the first information that needs to be used to calculate channel fluctuations, so that the first communication device can more accurately determine whether to trigger the second communication device to send the feedback result.

[0050] Optionally, the first communication device may receive a first PPDU, where the first PPDU includes first information, including but not limited to at least one of the following types of information: CSI measurement quantity indication information required for channel variation calculation, CSI type for channel variation calculation, information on a rule for channel variation calculation, or feedback suggestion parameters.

[0051] The first communication device may determine, based on the first PPDU, whether to trigger the second communication device to send a feedback result.

[0052] Optionally, the first communication device may further transmit a third PPDU, where the third PPDU is used to trigger the second communication device to transmit a feedback result, and the first communication device receives the feedback result transmitted by the second communication device.

[0053] In a possible design, the first PPDU may further include second information, where the second information indicates whether the channel fluctuation exceeds a specified fluctuation threshold.

[0054] In a possible design, the CSI measurement quantity indication information required for channel variation calculation includes at least one of the following types: an indication information indicating whether more measurements are needed, a total number of measurements, or a remaining number of measurements.

[0055] In a possible design, the CSI type for channel variation calculation includes at least one of the following types: currently measured CSI, CSI whose measurement time exceeds a specified time threshold, CSI whose measurement quantity exceeds a specified quantity threshold, previously measured CSI, first measured CSI, average CSI, numbered CSI, or flagged CSI.

[0056] In a possible design, the feedback suggestion parameter may include at least one of the following types: a feedback type, a number of subcarriers in a subcarrier group, a number of bits of codebook information, or a number of bits of CSI.

[0057] In a possible design, the first information may be carried in a MAC frame of the first PPDU, or the first information may be carried in a PHY preamble of the first PPDU.

[0058] According to a fourth aspect, a feedback method is provided. The method may be implemented by an interaction between a first communication device and a second communication device. The first communication device may be an AP, and the second communication device may be a STA. This is merely an illustrative example, and the specific types of the first communication device and the second communication device are not particularly limited.

[0059] The second communication device receives a second PPDU, where the second PPDU includes third information, which is used to request or notify the first information. The third information includes, but is not limited to, at least one of the following types of information: CSI measurement quantity indication information required for channel variation calculation, CSI type for channel variation calculation, information on a rule for channel variation calculation, feedback suggestion parameters, or indication information for clearing CSI.

[0060] The second communication device may calculate a channel variation based on the third information.

[0061] Optionally, the second communication device may transmit a first PPDU, where the first PPDU includes first information, including but not limited to at least one of the following types of information: CSI measurement quantity indication information required for channel variation calculation, CSI type for channel variation calculation, information on a rule for channel variation calculation, or feedback suggestion parameters.

[0062] Optionally, the second communication device may further receive a third PPDU, where the third PPDU is used to trigger the second communication device to send a feedback result, and the second communication device sends the feedback result.

[0063] In a possible design, the first PPDU may further include second information, where the second information indicates whether the channel fluctuation exceeds a specified fluctuation threshold.

[0064] In a possible design, the CSI measurement quantity indication information required for channel variation calculation includes at least one of the following types: an indication information indicating whether more measurements are needed, a total number of measurements, or a remaining number of measurements.

[0065] In a possible design, the CSI type for channel variation calculation includes at least one of the following types: currently measured CSI, CSI whose measurement time exceeds a specified time threshold, CSI whose measurement quantity exceeds a specified quantity threshold, previously measured CSI, first measured CSI, average CSI, numbered CSI, or flagged CSI.

[0066] In a possible design, the feedback suggestion parameter may include at least one of the following types: a feedback type, a number of subcarriers in a subcarrier group, a number of bits of codebook information, or a number of bits of CSI.

[0067] In a possible design, the first information may be carried in a MAC frame of the first PPDU, or the first information may be carried in a PHY preamble of the first PPDU.

[0068] According to a fifth aspect, there is provided a communication device, which may be a first communication device or a second communication device, or a chip disposed within the first communication device or the second communication device, and which may implement the method of the first aspect, the second aspect, the third aspect, or the fourth aspect.

[0069] When the communication device is a first communication device, optionally the communication device includes a processing unit and a transceiver unit.

[0070] For example, the transceiver unit is configured to receive a first PPDU, where the first PPDU includes first information, and the first information includes at least one of the following types of information: CSI measurement quantity indication information required for channel variation calculation, CSI type for channel variation calculation, information about a rule for channel variation calculation, or a feedback suggestion parameter, where the feedback suggestion parameter indicates a suggested feedback form.

[0071] The processing unit is configured to determine, based on the first information, whether to trigger the second communication device to send a feedback result.

[0072] In a possible design, the first PPDU further includes second information, where the second information indicates whether the channel fluctuation exceeds a specified fluctuation threshold.

[0073] In a possible design, the transceiver unit is further configured to transmit a second PPDU, where the second PPDU includes third information, and the third information is used to request or notify the first information.

[0074] In a possible design, the third information includes at least one of the following types: CSI measurement quantity indication information required for channel variation calculation, CSI type for channel variation calculation, information on a rule for channel variation calculation, feedback suggestion parameters, or indication information for clearing CSI.

[0075] In a possible design, the CSI measurement quantity indication information required for channel variation calculation includes at least one of the following types: an indication information indicating whether more measurements are needed, a total number of measurements, or a remaining number of measurements.

[0076] In a possible design, the CSI type for channel variation calculation includes at least one of the following types: currently measured CSI, CSI whose measurement time exceeds a specified time threshold, CSI whose measurement quantity exceeds a specified quantity threshold, previously measured CSI, first measured CSI, average CSI, numbered CSI, or flagged CSI.

[0077] In a possible design, the feedback suggestion parameter may include at least one of the following types: a feedback type, a number of subcarriers in a subcarrier group, a number of bits of codebook information, or a number of bits of CSI.

[0078] In a possible design, the first information may be carried in a MAC frame of the first PPDU, or the first information may be carried in a PHY preamble of the first PPDU.

[0079] When the communication device is a second communication device, the processing unit is configured to generate a first PPDU, where the first PPDU includes first information, and the first information includes at least one of the following types of information: CSI measurement quantity indication information required for channel variation calculation, CSI type for channel variation calculation, information about a rule for channel variation calculation, or feedback suggestion parameter, where the feedback suggestion parameter indicates a suggested feedback form; The transceiver unit is configured to transmit a first PPDU.

[0080] In a possible design, the first PPDU further includes second information, where the second information indicates whether the channel fluctuation exceeds a specified fluctuation threshold.

[0081] In a possible design, the transceiver unit is further configured to receive a second PPDU, where the second PPDU includes third information, and the third information is used to request or notify the first information.

[0082] In a possible design, the third information includes at least one of the following types: CSI measurement quantity indication information required for channel variation calculation, CSI type for channel variation calculation, information on a rule for channel variation calculation, feedback suggestion parameters, or indication information for clearing CSI.

[0083] In a possible design, the CSI measurement quantity indication information required for channel variation calculation includes at least one of the following types: an indication information indicating whether more measurements are needed, a total number of measurements, or a remaining number of measurements.

[0084] In a possible design, the CSI type for channel variation calculation includes at least one of the following types: currently measured CSI, CSI whose measurement time exceeds a specified time threshold, CSI whose measurement quantity exceeds a specified quantity threshold, previously measured CSI, first measured CSI, average CSI, numbered CSI, or flagged CSI.

[0085] In a possible design, the feedback suggestion parameter may include at least one of the following types: a feedback type, a number of subcarriers in a subcarrier group, a number of bits of codebook information, or a number of bits of CSI.

[0086] In a possible design, the first information may be carried in a MAC frame of the first PPDU, or the first information may be carried in a PHY preamble of the first PPDU.

[0087] According to a sixth aspect, there is provided a communications device including a processor configured to perform the method of the first, second, third or fourth aspect.

[0088] Optionally, the apparatus further includes a memory, the memory storing instructions, and the processor executing the instructions in the memory to perform the method of the first aspect, the second aspect, the third aspect, or the fourth aspect.

[0089] Optionally, the memory is located internal or external to the device.

[0090] Optionally, the apparatus further comprises an interface circuit, the processor being coupled to the interface circuit.

[0091] Optionally, there are one or more processors and one or more memories.

[0092] Optionally, the memory may be integral with the processor, or the memory and processor may be located separately.

[0093] In a particular implementation, the memory may be a non-transitory memory such as a read-only memory (ROM). The memory and the processor may be integrated into one chip or may be separately located on different chips. The type of memory and the manner in which the memory and the processor are located are not limited to the embodiments of the present application.

[0094] The communication device may be a chip, and the processor may be implemented using hardware or software. When implemented using hardware, the processor may be a logic circuit, an integrated circuit, or the like. When implemented using software, the processor may be a general-purpose processor and is implemented by reading software code stored in a memory, which may be integrated into the processor or located separately from the processor.

[0095] According to a seventh aspect, there is provided a processor including an input circuit, an output circuit, and a processing circuit configured to receive signals using the input circuit and transmit signals using the output circuit to enable the processor to perform a method of the first, second, third, or fourth aspect.

[0096] In a specific implementation process, the processor may be a chip, the input circuit may be an input pin, the output circuit may be an output pin, and the processing circuit may be a transistor, a gate circuit, a trigger, or various logic circuits, etc. An input signal received by an input circuit may be, for example, but not limited to, received and input by a receiver, and a signal output by an output circuit may be, for example, but not limited to, output to a transmitter and transmitted by the transmitter, and the input circuit and the output circuit may be the same circuit, in which case this circuit is used as an input circuit and an output circuit at different times. The specific implementation of the processor and various circuits is not limited to the embodiments of the present application.

[0097] According to an eighth aspect, there is provided a computer program product, the computer program product including a computer program (sometimes called code or instructions) that, when executed, enables a computer to perform the method of the first, second, third or fourth aspect.

[0098] According to a ninth aspect, there is provided a computer-readable medium storing a computer program (sometimes called code or instructions) that, when executed on a computer, enables the computer to perform the method of the first, second, third, or fourth aspect.

[0099] According to a tenth aspect, there is provided a chip system. The chip system includes a processor and an interface, and is configured to support a communication device to perform the functions of the first, second, third, or fourth aspects. In a possible design, the chip system further includes a memory, and the memory is configured to store information and data required by the communication device. The chip system may include a chip, or may include a chip and another discrete component.

[0100] According to an eleventh aspect, there is provided a functional entity, the functional entity being configured to perform the method of the first, second, third or fourth aspect.

[0101] According to a twelfth aspect, there is provided a communication system including a first communication device and a second communication device according to the first, second, third or fourth aspect.

[0102] Regarding the technical effects provided by the second aspect or any design manner of the fourth to twelfth aspects, please refer to the technical effects provided by the first or third aspect, and the details will not be repeated in this specification. [Brief explanation of the drawings]

[0103] [Figure 1] FIG. 1 is a schematic diagram of a communication system. [Figure 2] FIG. 1 is a schematic diagram of a communication system. [Figure 3] FIG. 1 is a schematic diagram of a communication system. [Figure 4a] 1 is a schematic diagram of a communication system in a Home environment; [Figure 4b] 1 is a schematic diagram of a communication system in an office environment. [Figure 5] FIG. 2 is a schematic diagram of the functional modules of the main control node and the measurement node. [Figure 6] FIG. 1 is a schematic diagram of the sensing process. [Figure 7] FIG. 1 is a schematic diagram of a feedback process according to an embodiment of the present application. [Figure 8] 2 is a schematic diagram of a structure of a PPDU frame according to an embodiment of the present application; [Figure 9] 2 is a schematic diagram of a structure of a PPDU frame according to an embodiment of the present application; [Figure 10] 2 is a schematic diagram of a structure of a PPDU frame according to an embodiment of the present application; [Figure 11]FIG. 2 is a schematic diagram of a sensing process according to an embodiment of the present application. [Figure 12] FIG. 1 is a schematic diagram of a feedback process according to an embodiment of the present application. [Figure 13] FIG. 2 is a schematic diagram of a sensing process according to an embodiment of the present application. [Figure 14] 1 is a schematic diagram of the structure of a communication device according to an embodiment of the present application; [Figure 15] 1 is a schematic diagram of the structure of a communication device according to an embodiment of the present application; [Figure 16] 1 is a schematic diagram of the structure of a communication device according to an embodiment of the present application; DETAILED DESCRIPTION OF THE INVENTION

[0104] The technical solutions of the present application will be described below with reference to the accompanying drawings.

[0105] The term "and / or" in this application describes an associative relationship between related objects and represents three possible relationships. For example, A and / or B may represent three cases: A is present only, both A and B are present, and B is present only. The character " / " generally indicates an "or" relationship between related objects. In this application, "at least one" refers to one or more, and "multiple" refers to two or more. Furthermore, it should be understood that in this description, terms such as "first" and "second" are used merely for distinction and explanation purposes and should not be understood as indicating or implying relative importance or indicating or implying an order.

[0106] Furthermore, in this application, unless otherwise specified, identical or similar parts in the embodiments will be mutually referenced. In the embodiments and implementations / implementation methods of the embodiments of this application, unless otherwise specified or unless a logical contradiction occurs, the terms and / or descriptions are consistent and may be mutually referenced between different embodiments and implementations / implementation methods of the embodiments. The technical features in different embodiments and implementations / implementation methods of the embodiments may be combined based on their internal logical relationships to form new embodiments, implementations, or implementation methods. The following implementations of this application are not intended to limit the protection scope of this application.

[0107] The technical solutions of the embodiments of the present application may be applied to various communication systems, such as wireless local area network (WLAN) communication systems, long term evolution (LTE) systems, LTE frequency division duplex (FDD) systems, LTE time division duplex (TDD) systems, universal mobile telecommunications system (UMTS), worldwide interoperability for microwave access (WiMAX) communication systems, fifth generation (5G) systems, new radio (NR), and future sixth generation (6G) systems.

[0108] For example, the following uses a WLAN system as an example to describe the application scenarios of the present application and the methods of the embodiments of the present application.

[0109] In particular, embodiments of the present application may be applied to a WLAN system, and may be applied to any protocol of the Institute of Electrical and Electronics Engineers (IEEE) 802.11 series of protocols used in a WLAN, such as 802.11a / b / g, 802.11n, 802.11ac, 802.11ax, 802.11be, 802.11bf, and future 802.11 protocols. The methods provided herein may be implemented by a communication device in a wireless communication system, or a chip or processor in a communication device. Accordingly, the communication device is capable of communication using the IEEE 802.11 series of protocols.

[0110] Although embodiments herein are primarily described using examples in which IEEE 802.11 networks are deployed, one skilled in the art will readily appreciate that aspects included herein may be extended to other networks using different standards or protocols, such as Bluetooth, high performance radio LAN (HIPERLAN) (a wireless standard similar to the IEEE 802.11 standard and used primarily in Europe), wide area networks (WANs), wireless local area networks (WLANs), personal area networks (PANs), or other known or later-developed networks. Thus, various aspects provided herein are applicable to any suitable wireless network, regardless of coverage area and wireless access protocol.

[0111] Furthermore, the communication system in this application is merely an example for explanation, and the communication system applicable to this application is not limited thereto. A collective description is provided in this specification, and details will not be described below.

[0112] To facilitate understanding of the embodiments of the present application, a communication system applicable to the embodiments of the present application will first be described in detail using the communication system shown in FIG. 1 as an example.

[0113] The system in the scenario shown in Fig. 1 is a WLAN system, which may include one or more APs and one or more STAs. The APs are, for example, AP#1 and AP#2 in Fig. 1, and the STAs are, for example, STA#1 and STA#2 in Fig. 1.

[0114] An AP is an access point for terminal devices (such as mobile phones) to access a wired (or wireless) network, and is primarily deployed in homes, buildings, and campuses. The typical effective radius of an AP is from several tens of meters to over a hundred meters. Of course, APs can also be deployed outdoors. An access point is equivalent to a bridge connecting a wired network to a wireless network. The main function of an access point is to connect various wireless network clients to each other and then connect the wireless network to an Ethernet. In particular, an AP can be an end device (such as a mobile phone) or a network device (such as a router) equipped with a Wireless Fidelity (Wi-Fi) chip. An access point can be a device that supports multiple WLAN standards in the 802.11 family, such as 802.11ax, 802.11ac, 802.11n, 802.11g, 802.11b, 802.11a, 802.11be, 802.11be next generation, and 802.11bf.

[0115] The access point may include a processor, a transmitter, and a receiver, where the processor is configured to control and manage the actions of the access point, the transmitter is configured to transmit information, and the receiver is configured to receive information.

[0116] The STA may be a wireless communication chip, a wireless sensor, a wireless communication terminal, or the like, and may also be referred to as user equipment. For example, the station may be a mobile phone, a tablet computer, a set-top box, a smart television set, a smart wearable device, an in-vehicle communication device, or a computer that supports Wi-Fi communication. Optionally, the station may support multiple WLAN standards of the 802.11 family, such as 802.11ax, 802.11ac, 802.11n, 802.11g, 802.11b, 802.11a, 802.11be, 802.11be next-generation, and 802.11bf.

[0117] An STA may include a processor, a transmitter, and a receiver, where the processor is configured to control and manage the actions of the STA, the transmitter is configured to transmit information, and the receiver is configured to receive information.

[0118] For example, the APs and STAs may be communication servers, switches, bridges, computers, and mobile phones, and the APs and STAs may be devices applied in the Internet of Vehicles, nodes or sensors of the Internet of Things (IoT), smart cameras, smart remote control devices, smart water meters or smart electricity meters in smart homes, or sensors of smart cities.

[0119] The access point and the station in the embodiments of the present application may be collectively referred to as a communication device. The communication device may include a hardware structure and a software module, and the above functions are implemented in the form of a hardware structure, a software module, or a combination of a hardware structure and a software module. The functions among the above functions may be implemented in the form of a hardware structure, a software module, or a combination of a hardware structure and a software module.

[0120] In a WLAN scenario, WLAN sensing can be implemented based on wireless passive sensing technology. Wireless passive sensing is a technology that uses the influence of a human body / object on radio waves to detect the presence, action, and movement of the human body / object. This is because, when communicating wirelessly, the communication device senses the interference of the human body / object with radio waves, and the human body / object can be sensed using this interference.

[0121] In a WLAN sensing process, a sensing transmitter may trigger channel measurements, and the sensing transmitter is hereinafter referred to as a transmitter for short. A sensing receiver may be configured to perform channel measurements, and the sensing receiver is hereinafter referred to as a receiver for short. A sensing initiator may be configured to start a sensing session, and the sensing session is used to trigger feedback of information related to the channel measurements. The sensing initiator is hereinafter referred to as an initiator for short. A sensing responder may be configured to participate in the sensing session and return information related to the channel measurements, and the sensing responder is hereinafter referred to as a responder for short. For example, the information related to the channel measurements includes channel measurement results and / or channel variations. The transmitter may be an AP or a STA, the receiver may be an AP or a STA, the initiator may be an AP or a STA, and the responder may be an AP or a STA. The sender and initiator may be the same physical device or different physical devices, and the receiver and responder may be the same physical device or different physical devices.

[0122] During channel measurement, the transmitter may include training symbols in a measurement packet, which may be an orthogonal frequency division multiplexing (OFDM) subcarrier group. The receiver performs channel measurement based on the structure of the training symbols and obtains CSI corresponding to each subcarrier group. The channel measurement result may be represented by CSI, which may reflect the status of the channel between the communication devices.

[0123] The receiver may determine the channel variation based on the results of multiple channel measurements. For example, the receiver may determine the channel variation by comparing multiple CSIs. Optionally, the receiver may determine the channel variation based on whether the channel variation satisfies a predetermined condition. When the channel variation does not satisfy the predetermined condition, the channel variation may be considered small. When the channel variation satisfies the predetermined condition, the channel variation may be considered large. The channel variation not satisfying the predetermined condition may be expressed in other ways. For example, the channel variation does not exceed a specified variation threshold (specifically, the channel variation is less than or equal to the specified variation threshold), or the channel condition similarity is greater than a threshold, etc. This is not limited in this specification. The channel variation satisfying the predetermined condition may also be expressed in other ways. For example, the channel variation exceeds a specified variation threshold (specifically, the channel variation is greater than or equal to the specified variation threshold), or the channel condition similarity is less than a threshold, etc.

[0124] 2 is a schematic diagram of a WLAN sensing process applicable to embodiments of the present application. A WLAN system includes one or more transmitters (e.g., transmitter 101 in FIG. 2) and one or more receivers (e.g., receiver 102 in FIG. 2). The transmitter and receiver may be located in the same physical device or in different physical devices.

[0125] During channel measurement, the transmitter 101 transmits a signal, and the receiver 102 receives the signal. The signal received by the receiver 102 may include a direct path signal 104 (a signal not affected by the detection target 103) and an influence signal 105 (a signal affected by the detection target 103). When the detection target 103 moves, the influence signal 105 changes. The superimposed wireless signal of the direct path signal 104 and the influence signal 105 received by the receiver 102 also changes accordingly. In this way, the receiver 102 detects that the wireless channel is changing. The change in the wireless channel may be represented by a change in the amplitude and phase of the CSI.

[0126] The receiver 102 may determine the CSI variation, i.e., the channel variation, based on the results of two (or more) CSI measurements and a predetermined condition. For example, when the CSI variation meets the predetermined condition, the receiver 102 determines that the CSI variation is large. When the CSI variation does not meet the predetermined condition, the receiver 102 determines that the CSI variation is small. When the CSI variation is large, the transmitter 101 may further interact with the receiver 102 to obtain more accurate channel measurement results.

[0127] Compared to using wearable devices such as cameras or wristbands for sensing, wireless passive sensing technology does not require additional hardware costs and does not require users to wear a device. Wireless passive sensing technology facilitates monitoring of the elderly and children, detecting possible intrusions and other situations. Furthermore, wireless passive sensing technology has little impact on users' privacy and can monitor bedrooms and bathrooms, providing more comprehensive protection. Furthermore, wireless passive sensing technology can perform effective sensing even when lighting is poor or there are obstacles (such as curtains and wooden furniture), and can even sense multiple rooms through walls. Wireless passive wireless technology has high wireless sensing accuracy and can perform gesture recognition and sleep respiration monitoring.

[0128] The WLAN sensing process shown in Fig. 2 is applicable to the architecture diagram of a communication system shown in Fig. 3. This communication system includes one or more main control nodes, such as main control node 201 and another main control node 205 in Fig. 3. This communication system further includes one or more measurement nodes, such as measurement node 202, measurement node 203, and measurement node 204 in Fig. 3. The link transmitted by the measurement node and the link received by the main control node are referred to as uplink 210. The link transmitted by the main control node and the link received by the measurement node are referred to as downlink 211. The main control node 201 interacts with another main control node 205 via a control link 212. The control link 212 may be connected using a wired Ethernet or a wireless network and may be configured to coordinate different main control nodes to perform detection.

[0129] The master control node may be a network element supporting Wi-Fi or another wireless network protocol. For example, the master control node may be deployed in a WLAN AP or a smart home control center. The measurement nodes may be mobile devices such as mobile phones, or devices integrated with WLAN functionality, such as printers, intelligent printers, or intelligent electric lamps. The master control node and the measurement nodes may interact with each other using a wireless network protocol (e.g., a Wi-Fi protocol). The master control node may send downlink measurement packets to the measurement nodes and coordinate the measurement nodes to perform CSI measurements to obtain the presence and movement status of surrounding people / objects.

[0130] A transmitter in a measurement process may be either a main control node or a measurement node, and a receiver may be either a main control node or a measurement node. In other words, a main control node may be either a transmitter or a receiver in a measurement process, and a measurement node may be either a transmitter or a receiver in a measurement process. In some possible cases, the main control node may not be either a transmitter or a receiver, but may control multiple measurement nodes to function separately as transmitters or receivers, etc. This is not limited to this embodiment of the present application.

[0131] The communication system shown in FIG. 3 may be applied to home and office scenarios.

[0132] A possible home scenario is shown in Fig. 4a. In the home environment shown in Fig. 4a, one main control node 301 and multiple measurement nodes, such as measurement node 302, measurement node 303, measurement node 304, measurement node 305, measurement node 306, measurement node 307, and measurement node 308, are deployed. The main control node 301 may perform measurement interactions with the multiple measurement nodes to monitor the entire home environment. For example, the link between the main control node 301 and measurement node 305 may be used to measure the action status of a bathroom. If a fall action is detected, the main control node 301 may send an alert to parents, medical personnel, etc. in time. In another example, the links between the main control node 301 and measurement node 302, measurement node 303, and measurement node 306 may be used to measure the situation in a bedroom and monitor a user's sleep status.

[0133] Office scenarios may include industrial and commercial environments. A possible office scenario is shown in FIG. 4b. In an office scenario, the monitored area is usually large, and multiple master control nodes may be used, such as master control node 401, master control node 402, and master control node 403. The master control node interacts with different measurement nodes to measure a specific area. For example, the link between master control node 401 and measurement node 410 may be used to monitor door entry and exit status. In another example, the link between master control node 403 and measurement node 413 may be used to collect statistics about conference room occupancy and the number of conference participants.

[0134] Optionally, the main control node and the measurement node may be implemented using the functional modules of Figure 5. Figure 5 is a schematic diagram of the structure of a main control node functional module and a schematic diagram of the structure of a measurement node functional module according to an embodiment of the present application.

[0135] The master control node function module includes a master control node selection module 501, a measurement node status recording module 502, a measurement procedure interaction module 503, a CSI information processing module 504, and a CSI measurement module 505. The master control node selection module 501 may be responsible for selecting a master control node from multiple nodes that can assume the task of the master control node and may also be responsible for interactions between master control nodes. The measurement node status recording module 502 may be responsible for storing information of all measurement nodes under the master control node. The measurement node information includes, but is not limited to, at least one of the following information: measurement node identifier (e.g., the MAC address of the measurement node and the association identifier (AID) of the measurement node), sensing identifiers (SIDs) assigned to unassociated measurement nodes, measurement capabilities of the measurement node, location of the measurement node, historical CSI measurement information of the measurement node, and predefined conditions for triggering sensing by the measurement node. The measurement procedure interaction module 503 may be responsible for protocol processing of the interaction between the main control node and the measurement node. The CSI information processing module 504 may be responsible for processing the collected CSI information. The CSI measurement module 505 may be responsible for measuring training symbols in measurement packets transmitted by the measurement nodes, may output an uplink CSI measurement matrix for each subcarrier or subcarrier group after receiving the measurement packets, and may be responsible for transmitting the uplink CSI measurement matrix to the CSI information processing module 504 for subsequent processing.

[0136] The measurement node function module includes a measurement procedure interaction module 510, a CSI measurement module 511, and a measurement node local information module 512. The measurement procedure interaction module 510 may be responsible for responding to measurement interaction information of the master control node. The CSI measurement module 511 may be responsible for measuring measurement packets transmitted by the master control node and obtaining a downlink CSI measurement matrix. The measurement node local information module 512 may be responsible for storing information related to the measurement. The information related to the measurement includes, but is not limited to, at least one of the following information: a measurement session identifier, a CSI last measured by the measurement node, and a timestamp last fed back by the measurement node, etc.

[0137] 5 may be implemented using hardware chips or by firmware refresh, or some of the functional modules (e.g., the master control node selection module 501 or the CSI information processing module 504) may be implemented by operating system or driver software.

[0138] It may be understood that the structure shown in FIG. 5 is not a specific limitation for the master control node and the measurement nodes. For example, in some other embodiments of the present application, the master control node and the measurement nodes may include more or fewer components than those shown in this figure, some components may be combined, some components may be split, or these components may be arranged differently. The components shown in this figure may be implemented by hardware, software, or a combination of software and hardware. For example, the master control node may include a transceiver, a memory, and a processor. The transceiver may implement the functionality of the measurement procedure interaction module 503, the memory may implement the functionality of the measurement node status recording module 502, and the processor may implement the functionality of the master control node selection module 501, the CSI information processing module 504, and the CSI measurement module 505. In another example, the master control node may include a transceiver, a memory, and a processor. The transceiver may implement the functionality of a measurement procedure interaction module 510, the memory may implement the functionality of a measurement node local information module 512, and the processor may implement the functionality of a CSI measurement module 511.

[0139] FIG. 6 is a schematic diagram of a possible channel measurement process. In the measurement phase, a transmitter sends an NDPA and an NDP to instruct one or more receivers to perform channel measurements (also called CSI measurements). In the reporting phase, the transmitter sends a feedback request to request feedback of channel variations, and receiver 1 sends a feedback response carrying condition met information (Met) indicating that the channel variations meet a predetermined condition. Receiver 2 sends a feedback response carrying condition not met information (Not Met) indicating that the channel variations do not meet the predetermined condition. The transmitter triggers the receiver that sends the Met information to feedback the channel measurement results. For example, the transmitter sends a feedback trigger to receiver 1, which is used to trigger the channel measurement results, and receiver 1 returns the channel measurement results.

[0140] In this specification, the receiver only feeds back Met information or Not Met information, which indicates that the channel fluctuation is unreliable. However, the transmitter cannot accurately determine whether to trigger the receiver to feed back the channel measurement result based on Met information or Not Met information alone. As a result, the accuracy of the channel measurement is reduced.

[0141] Based on this, an embodiment of the present application provides a feedback method. The following describes in detail the feedback method provided in the embodiment of the present application using an example in which a first communication device interacts with a second communication device. The first communication device may be a sensing transmitter, and the processing process in the transmitter may be completed by a sensing initiator. In a possible scenario, the measurement phase may be completed by the transmitter, and the reporting phase may be completed by the initiator. The second communication device may be a sensing receiver, and the processing process in the receiver may be completed by a sensing responder. The first communication device may be both a transmitter and a receiver, i.e., the first communication device may implement the functions of a transmitter and a receiver (e.g., the first communication device may be a radar). Alternatively, the first communication device may be both an initiator and a responder. The second communication device may also be both a transmitter and a receiver, or both an initiator and a responder.

[0142] It may be understood that in the embodiments of the present application, the first communication device and / or the second communication device may perform some or all of the steps in the embodiments of the present application. These steps or operations are merely examples. Other operations or variations of various operations may also be performed in the embodiments of the present application. Furthermore, the steps may be performed in an order different from that presented in the embodiments of the present application, and not all operations of the embodiments of the present application may be performed.

[0143] It should be noted that in the following embodiments of the present application, the names of messages between devices or the names of parameters in messages between devices are merely examples, and the messages or parameters may have other names in a specific implementation, which is not particularly limited in the embodiments of the present application.

[0144] In the feedback method provided in the embodiment of the present application, the first information includes at least one of the following types of information: channel state information (CSI measurement quantity indicator information) required for channel variation calculation, CSI type for channel variation calculation, information on the channel variation calculation rule, or feedback suggestion parameters. The first information is used as another type of information related to the channel measurement result and is used to select the second communication device to which the feedback result will be sent. Therefore, compared with the case where the first communication device only uses whether the channel variation satisfies a predetermined condition as a trigger condition, the first communication device can more accurately determine one or more triggered second communication devices based on the received first information, and the triggered one or more second communication devices will send the feedback result. In this way, the accuracy of channel measurement can be improved.

[0145] 7 shows a feedback method according to an embodiment of the present application. There may be one or more first communication devices, and there may be one or more second communication devices. In this embodiment of the present application, an example in which there is one first communication device and multiple second communication devices is used for explanation. In detail, the feedback method includes the following steps:

[0146] S701: A second communication device generates a first PPDU.

[0147] S702: A second communication device transmits a first PPDU.

[0148] In response, the first communication device receives the first PPDU.

[0149] The first PPDU includes first information, which is another type of information related to a channel measurement result. The first information is different from the information indicating the channel measurement result and the channel variation described above. The first information may instruct the first communication device to determine a second communication device to trigger a feedback result. That is, the first communication device may select a second communication device to transmit the feedback result to based on the first information. The first information may further indicate a manner in which the first communication device triggers the feedback result. That is, the first communication device may determine a manner in which the first communication device triggers the feedback result based on the first information. For example, the first information may include information indicating a manner in which the feedback result is triggered.

[0150] The method of triggering the feedback result may be at least one of the following methods: triggering using a feedback request frame, triggering using a feedback trigger frame, or triggering using a polling frame.

[0151] Optionally, the first PPDU may further include second information, and the second information may indicate whether the channel variation satisfies a predetermined condition.

[0152] Optionally, the first PPDU may further include fourth information, where the fourth information indicates a channel variability.

[0153] It should be noted that the first PPDU may carry the second information and the fourth information, or may carry only one of the second information and the fourth information. This is not limited in the present application. In an example, the first PPDU carries only the second information, and the first communication device may further determine whether the second communication device will transmit a feedback result based on the first information and the second information, and select the second communication device to transmit the feedback result, thereby further improving the accuracy of the determination. In another example, the first PPDU carries only the fourth information. In this specification, the first communication device and the second communication device may pre-negotiate a correspondence between the degree of channel variability and whether the channel variation satisfies a predetermined condition. The first communication device may determine whether the channel variation satisfies a predetermined condition based on the degree of channel variability, and further determine whether the second communication device will transmit a feedback result based on the determination result and the first information, and select the second communication device to transmit the feedback result, thereby further improving the accuracy of the determination. In yet another example, the first PPDU may carry second information and fourth information, and the first communication device may more accurately determine whether to send the feedback result to the second communication device based on the first information, the second information, and the fourth information.

[0154] Optionally, the first information is carried in a MAC frame of the first PPDU, i.e., a data field of the first PPDU includes the MAC frame, and the MAC frame includes the first information. For example, a new element may be defined, and the new element includes the first information. In another example, the first information may be included in an existing aggregation (A) control subfield. In an example, the first information may be carried in a command and status (CAS) control subfield. In another example, a new A-Control subfield may be defined. In an example, the new A-Control subfield may be defined by defining a new control ID, and the new A-Control subfield carries the first information.

[0155] Optionally, the first information is carried in a PHY preamble of the first PPDU.

[0156] In one possible example, the first PPDU may be fed back in a reporting phase, for example, the first PPDU may carry a feedback response frame, which includes a result indicating whether the channel fluctuation exceeds a specified fluctuation threshold.

[0157] The first information may include, but is not limited to, at least one of the following types of information: CSI measurement quantity indication information required for channel variation calculation, CSI type for channel variation calculation, information on a rule for channel variation calculation, or feedback suggestion parameter. The feedback suggestion parameter indicates a suggested feedback form. Four types of information that may be included in the first information in the form of Information 1 to 4 (i.e., Information 1 to Information 4) are described in detail below.

[0158] Information 1: CSI measurement quantity display information required for channel fluctuation calculation.

[0159] This information may be that shown in Table 1 and may include, but is not limited to, at least one of the following types of information: indication information indicating whether more measurements are needed, the total number of measurements, or the remaining number of measurements.

[0160] [Table 1]

[0161] The information contained in the CSI measurement quantity indication information required for channel fluctuation calculation will be described in detail below.

[0162] (1) Information indicating whether more measurements are needed.

[0163] This information may indicate whether the channel variation can be determined based on the current number of measurements, i.e., whether more measurements are needed to determine the channel variation.

[0164] For example, one bit may be used to indicate whether more measurements are needed. For example, when the value of this one bit is 0, it indicates that the channel variation cannot be determined based on the current number of measurements and more measurements are needed. When the value of this one bit is 1, it indicates that the channel variation can be determined based on the current number of measurements and more measurements are not needed. In another example, when the value of this one bit is 1, it indicates that the channel variation cannot be determined based on the current number of measurements and more measurements are needed. When the value of this one bit is 0, it indicates that the channel variation can be determined based on the current number of measurements and more measurements are not needed.

[0165] Optionally, if the first information received by the first communication device includes indication information indicating that more measurements are needed, the first communication device may again trigger the second communication device, which transmits indication information indicating that more measurements are needed, to perform channel measurements. That is, the second communication device notifies the first communication device, based on the indication information included in the first information indicating that more measurements are needed, that the channel variation cannot be determined based on the current number of measurements and that more measurements are needed. In this case, the first communication device again triggers the second communication device to perform channel measurements so that the second communication device has a sufficient number of measurements to complete the channel measurement and determine the channel variation. In a possible scenario, the second communication device performs channel measurement only once. However, the channel variation can be determined based on results of multiple channel measurements (e.g., multiple CSIs). In this case, the second communication device may transmit indication information indicating that more measurements are needed.

[0166] If the first information received by the first communication device includes indication information indicating that no more measurements are needed, the first communication device may determine that the second communication device has a sufficient number of measurements to complete channel measurements, i.e., the first communication device may determine that the second communication device can calculate channel variations, and the first communication device may trigger the second communication device to send feedback results.

[0167] (2) Total number of measurements

[0168] The information may indicate a total number of measurements required to determine channel variations. The total number of measurements is a positive integer. Optionally, the first communication device may determine whether to trigger or continue to trigger the second communication device to perform channel measurements based on the total number of measurements and the current number of measurements. The current number of measurements may be the number of channel measurements that the first communication device has triggered the second communication device to perform. In a possible implementation, each time the first communication device triggers the second communication device to perform channel measurements, the first communication device may update the current number of measurements of the second communication device stored in the first communication device.

[0169] Optionally, if the first communication device determines that the current number of measurements of the second communication device has reached the total number of measurements, the first communication device may trigger the second communication device to send a feedback result, whereas if the first communication device determines that the target number of measurements of the second communication device has not reached the total number of measurements, the first communication device may trigger the second communication device to perform channel measurements without triggering the second communication device to send a feedback result.

[0170] (3) Remaining quantity of measurements

[0171] The information may indicate a number of measurements still needed to determine the channel variation. The remaining number of measurements is a non-negative integer. Optionally, when the remaining number of measurements is not zero, the first communication device may continue to trigger the second communication device to perform channel measurements. When the remaining number of measurements is not zero, the first communication device may trigger the second communication device to transmit a feedback result.

[0172] It should be noted that the indication information of the number of CSI measurements required for channel variation calculation may include any one of the indication information indicating whether more measurements are required, the total number of measurements, and the remaining number of measurements, or may be a combination of these information, which is not limited in the present application.

[0173] For example, the indication of the number of CSI measurements required for channel variation calculation may include an indication of whether more measurements are needed and the remaining number of measurements. That is, the second communication device not only notifies the first communication device of the indication of whether the second communication device needs to perform more measurements, but also notifies the first communication device of the number of measurements still needed by the second communication device to determine channel variation. This helps the first communication device to more accurately determine whether to trigger the second communication device to continue performing channel measurements based on the indication.

[0174] Information 2: CSI type for channel variation calculation

[0175] This information may be that shown in Table 2 and may include, but is not limited to, at least one of the following types of information: currently measured CSI, CSI where the measurement time exceeds a specified time threshold, CSI where the quantity of measurements exceeds a specified quantity threshold, previously measured CSI, first measured CSI, average CSI, numbered CSI, or flagged CSI.

[0176] [Table 2]

[0177] Below, we will explain in detail the CSI types for channel variation calculation.

[0178] (1) CSI measured this time

[0179] This CSI type may indicate that the channel variation is calculated based on the currently measured CSI, i.e., the channel variation is calculated based on the currently measured CSI, which is the most recently measured CSI, for example, the CSI whose measurement time is closest to the current time.

[0180] Optionally, the second communication device may calculate the channel variation based on the currently measured CSI by default. In this case, the first information may not carry the currently measured CSI or may not carry information indicating the currently measured CSI. If possible, the first communication device and the second communication device have pre-agreed to calculate the channel variation based on the currently measured CSI, and no additional signaling indication is required. Therefore, when the second communication device does not feed back the CSI type for the channel variation calculation, the first communication device assumes by default that the second communication device calculates the channel variation based on the currently measured CSI.

[0181] If the CSI type for channel variation calculation carries the currently measured CSI, it may be considered that the measurement time point of the currently measured CSI is close to the current time point, and therefore the channel variation calculated using the currently measured CSI can reflect the current scenario. In this case, the first communication device may more accurately determine whether to trigger the second communication device to transmit a feedback result based on the currently measured CSI.

[0182] (2) CSI whose measurement time exceeds a specified time threshold

[0183] This CSI type may indicate that the channel variation is calculated based on the CSI whose measurement time exceeds a specified time threshold. In this case, the channel variation may not reflect the current scenario. For channel variations that cannot reflect the current scenario, the first communication device may not trigger the second communication device to transmit a feedback result. CSI whose measurement time exceeds a specified time threshold may be considered as stale CSI. The specified time threshold is arbitrary and is not limited in this embodiment of the present application. For example, when the time difference between the measurement time of one CSI and the current time is greater than a specified time threshold, the CSI may be considered as a CSI whose measurement time exceeds a specified time threshold.

[0184] If the CSI type for channel variation calculation carries CSI whose measurement time point exceeds a specified time threshold, since a certain period of time has passed from the measurement time point of the CSI whose measurement time point exceeds the specified time threshold to the time point of the current scenario, the first communication device may consider that the channel variation may not reflect the current scenario, and then the first communication device further determines not to trigger the second communication device to transmit the feedback result.

[0185] (3) CSIs whose measurement quantities exceed a specified quantity threshold

[0186] This CSI type may indicate that the channel variation is calculated based on the CSI whose measurement quantity exceeds a specified quantity threshold. In this case, the channel variation may not reflect the current scenario. For channel variation that cannot reflect the current scenario, the first communication device may not trigger the second communication device to transmit a feedback result. The CSI whose measurement quantity exceeds the specified quantity threshold may be considered as stale CSI. The specified quantity threshold is arbitrary and is not limited in this embodiment of the present application. For example, when one or more CSI measurements are performed between the measurement time point of the first CSI and the measurement time point of the second CSI, and the quantity of the one or more CSI measurements is greater than the specified quantity threshold, the first CSI may be considered as the CSI whose measurement quantity exceeds the specified quantity threshold.

[0187] When the CSI type for the channel variation calculation carries CSI with a measurement quantity exceeding a specified quantity threshold, multiple CSI measurements are performed after the measurement time point of the CSI with a measurement quantity exceeding the specified quantity threshold, so it may be considered that a certain period has elapsed from the time point of the current scenario to the measurement time point of the CSI with a measurement quantity exceeding the specified quantity threshold. In this case, the first communication device may consider that the channel variation may not reflect the current scenario and may further determine not to trigger the second communication device to transmit a feedback result.

[0188] (4) Previously measured CSI

[0189] This CSI type may indicate that the channel variation is calculated based on the previously measured CSI, which is the CSI that is closest to the currently measured CSI, i.e., the measurement time of the previously measured CSI is closest to the measurement time of the currently measured CSI, and the measurement time of the previously measured CSI is earlier than the measurement time of the currently measured CSI.

[0190] If the CSI type for the channel variation calculation carries the previously measured CSI, the measurement time point of the previously measured CSI may be close to the current time point, so the channel variation calculated using the previously measured CSI may be considered to be able to reflect the current scenario. In this case, the first communication device may more accurately determine whether to trigger the second communication device to transmit a feedback result based on the currently measured CSI.

[0191] (5) First measured CSI

[0192] This CSI type may indicate that the channel variation is calculated based on the first-time measured CSI, which may be the CSI measured when the first communication device triggers channel measurement for the first time.

[0193] If the CSI type for the channel variation calculation carries first-time measured CSI and the time difference between the measurement time point of the first-time measured CSI and the current time point is large, the first communication device may decide not to trigger the second communication device to transmit the feedback result.If the time difference between the measurement time point of the first-time measured CSI and the current time point is small, the first communication device may decide to trigger the second communication device to transmit the feedback result.

[0194] (6) Average CSI

[0195] This CSI type may indicate that the channel variation is calculated based on an average CSI, which may be an average CSI calculated by the second communication device based on one or more CSIs.

[0196] (7) Numbered CSI

[0197] This CSI type may indicate that the channel variation is calculated based on numbered CSI. There may be one or more CSI numbers. The rule for numbering the CSI is random and is not limited in this embodiment of the present application. However, it must be ensured that the same numbering rule is pre-agreed between the first communication device and the second communication device.

[0198] When the CSI type for channel variation calculation carries numbered CSI, the CSI number is carried in the CSI type for channel variation calculation. For example, the second communication device may number the CSI obtained by performing channel measurement each time. In this manner, the first communication device may determine that the first information carries numbered CSI based on the CSI number and determine the CSI number. The CSI number may indicate which CSI obtained by which channel measurement the second communication device used to calculate the channel variation.

[0199] (8) Flagged CSI

[0200] This CSI type may indicate that the channel variation is calculated based on flagged CSI. The flagged CSI may be one or more CSIs, i.e., the second communication device stores flags for the one or more CSIs. The flagged CSI is optional. This is not limited in this embodiment of the present application. For example, the flagged CSI may be CSI that is measured for the first time.

[0201] If only one flagged CSI can be stored in the second communication device, the flag of the previously stored flagged CSI may be removed before the new CSI is flagged, i.e., the currently stored flagged CSI becomes unflagged.

[0202] It should be noted that the CSI type for channel variation calculation may include any one of the following, but is not limited to: the currently measured CSI, the CSI whose measurement time exceeds a specified time threshold, the CSI whose measurement quantity exceeds a specified quantity threshold, the previously measured CSI, the CSI measured for the first time, the average CSI, the numbered CSI, and the flagged CSI.

[0203] In a possible scenario, the first information transmitted by the second communication device includes a CSI type for channel variation calculation, and the CSI type for channel variation calculation carries currently measured CSI and flagged CSI, or carries currently measured CSI and first-time measured CSI. That is, the second communication device compares the currently measured CSI with the flagged CSI to determine channel variation. Alternatively, the second communication device compares the currently measured CSI with the first-time measured CSI to determine channel variation. Based on the first information, the first communication device determines that the second communication device can calculate channel variation and determines to trigger the second communication device to transmit a feedback result.

[0204] In this scenario, for a slowly moving object, the difference between the channel fluctuations calculated in two consecutive channel measurements is not excessively large (the CSI fluctuations are not excessively large). Therefore, the second communication device compares the currently measured CSI with the flagged CSI to determine the channel fluctuations, or the second communication device compares the currently measured CSI with the CSI measured for the first time to select the slowly moving object. This scenario is merely a possible example, and the slowly moving object may also be measured in another manner.

[0205] In another possible scenario, the first information transmitted by the second communication device includes a CSI type for channel variation calculation, and the CSI type for channel variation calculation carries currently measured CSI and previously measured CSI. That is, the second communication device compares the currently measured CSI with the previously measured CSI to determine the channel variation. Based on the first information, the first communication device determines that the second communication device can calculate the channel variation and determines to trigger the second communication device to transmit the feedback result.

[0206] In this scenario, for a fast-moving object, the difference between the channel variations calculated in two consecutive channel measurements is large (large CSI variation). Therefore, the second communication device compares the currently measured CSI with the previously measured CSI to determine the channel variation. In this way, the fast-moving object is selected. This scenario is merely a possible example, and fast-moving objects can also be measured in other ways.

[0207] Furthermore, in this scenario, for user gesture recognition, the changes in the user gesture are fast and of short duration, and the CSI measured each time is important. Therefore, the second communication device compares the currently measured CSI with the previously measured CSI to recognize the changes in the user gesture.

[0208] It can be understood that the above possible scenarios are merely used as examples and are not limitations on other possible scenarios. According to the method provided in this embodiment of the present application, different CSI types can be selected to perform channel variation estimation in different scenarios, so that the channel variation estimation can be more accurate and the accuracy of channel measurement can be improved.

[0209] Information 3: Information about the rules for calculating channel fluctuations

[0210] This information may indicate the rules for calculating channel variations.

[0211] In a possible implementation, the information about the rule of channel variation calculation may be a rule identifier. The second communication device may store one or more rules, such as Equation 1, Equation 2, and Equation 3. If the second communication device calculates the channel variation according to Equation 1, the information about the rule of channel variation calculation may be Equation 1.

[0212] For example, the channel variation calculation rule may be a formula for comparing channel difference or channel similarity, where higher similarity indicates smaller difference and smaller channel variation. For example, a similarity determination method that normalizes the product of two channel vectors is used. For example, the similarity determination method may be the following evaluation algorithm 1 or evaluation algorithm 2. For example, one bit may be used to represent information about the channel variation calculation rule. When the value of this one bit is 0, it indicates that the channel variation calculation rule is evaluation algorithm 1. When the value of this one bit is 1, it indicates that the channel variation calculation rule is evaluation algorithm 2.

[0213] In a possible implementation, evaluation algorithm 1 is a time-reversal resonating strength (TRRS) algorithm. TRRS is the maximum magnitude of the cross-correlation coefficient obtained by performing a convolution on two channel impulse responses (CIRs), and is used to measure the similarity between the two CIRs. A larger TRRS value indicates that the two CIRs are more similar and have less variation. The range of TRRS values ​​is [0, 1].

[0214] For the sensing target area, it is assumed that the CIR received by the STA during sensing measurement at time t1 is h1 = [h1[0], h1[1], ..., h1[L-1]], and the CIR received by the STA at time t2 is h2 = [h2[0], h2[1], ..., h2[L-1]], where L represents the length of the CIR sequence. When TRRS is lower than a predetermined threshold, it indicates that there is a large change between the two CIRs. In this case, CSI update and feedback need to be performed.

[0215] The TRRS between h1 and h2 is calculated by (Equation 2-1) and is represented as η(h1, h2).

[0216]

number

[0217] g2=[g2[0],g2[1],...,g2[L-1]], which is obtained by performing time reversal and conjugation on h2. g2[k]=h*2[L-1-k], where j=0, 1,...,L-1, and h*2 denotes the conjugate of h2.

[0218] Evaluation algorithm 2 is the Mahalanobis distance (MD) algorithm. Mahalanobis distance corrects for inconsistencies and dimensional correlations in Euclidean distance and is used to evaluate the similarity between data. MD is used to measure the similarity between two CIRs. A larger MD value indicates a greater difference, or change, between the two CIRs. The value range of the Mahalanobis distance is [0, +∞). The projection space of the Mahalanobis distance can be obtained by performing the following steps: rotating the variables according to the principal components to make the dimensions independent of each other, and then performing normalization to distribute the dimensions uniformly. From principal component analysis, we can see that the principal components are the directions of the eigenvectors, and the variance of each direction is the corresponding eigenvalue. Therefore, we simply rotate the variables according to the eigenvector directions and then scale the eigenvalues ​​by a factor.

[0219] For the sensing target area, it is assumed that the CIR received by the STA during sensing measurement at time t1 is h1 = [h1[0], h1[1], ..., h1[L-1]], and the CIR received by the STA at time t2 is h2 = [h2[0], h2[1], ..., h2[L-1]]. When MD is higher than a predetermined threshold, it indicates that there is a large change between the two CIRs. In this case, CSI update and feedback need to be performed.

[0220] The MD between h1 and h2 is calculated using (Equation 2-2) and is represented as d(h1, h2).

[0221]

number

[0222] Σ=cov(h1,h2)=E[(h1-E[h1])(h2-E[h2]) T] is the covariance matrix, where E[h1] represents the expectation of h1, and the superscript T represents the transpose of the matrix. This covariance matrix can simultaneously show the correlation between different dimensions and the correlation between the variances of each dimension. The elements on the main diagonal are the variances (i.e., energies) in each direction, and the other elements are the covariances (i.e., correlations) between the two dimensions.

[0223] Information 4: Feedback suggestion parameters

[0224] This information may be as shown in Table 3 and includes, but is not limited to, at least one of the following types of information: feedback type, number of subcarriers in a subcarrier group, number of bits of codebook information, number of bits of CSI, or indication information indicating whether further feedback is to be performed.

[0225] [Table 3]

[0226] The feedback suggestion parameters are described in detail below.

[0227] (1) Feedback type of feedback results

[0228] The feedback suggestion parameter may indicate a feedback type of the channel measurement result. For example, the feedback type of the channel measurement result may be any one of NDP, CSI, compressed CSI, or sensing measurement result. The data volume of the channel measurement result for different feedback types may be different. For example, the data volume of the compressed CSI data is different from the data volume of the CSI, and the data volume of the compressed CSI data is larger than the data volume of the CSI.

[0229] (2) The number of subcarriers in a subcarrier group

[0230] This feedback suggestion parameter may indicate the size of the subcarrier group, i.e., how many subcarriers are included in the group. The number of subcarriers in a subcarrier group may be represented by Ng. Ng may represent a grouping scheme of the subcarrier group. Before grouping, each subcarrier may feedback one CSI, and after grouping, multiple subcarriers in each subcarrier group may feedback one CSI. Therefore, the size of the CSI feedback may be reduced, and signaling overhead may be reduced.

[0231] (3) Number of bits of codebook information

[0232] This feedback suggestion parameter may indicate the number of bits to be occupied by the codebook information after quantization, ie, the codebook size.

[0233] (4) Number of CSI bits

[0234] The feedback suggestion parameter may indicate the number of bits occupied by the CSI after quantization. For example, the CSI may be a channel matrix, and the feedback suggestion parameter may indicate the number of bits occupied by each element of the channel matrix after quantization.

[0235] (5) Display information indicating whether further feedback is required

[0236] The feedback suggestion parameter may indicate whether the second communication device requests further feedback of the results. For example, if the first communication device receives indication information indicating that further feedback is needed, the first communication device may trigger the second communication device that sent the indication information indicating that further feedback is needed to send a feedback result. In another example, the first communication device receives indication information indicating that further feedback is not needed, which indicates that the second communication device does not request further feedback (e.g., when the second communication device has not calculated channel variation). In this case, the first communication device may not trigger the second communication device to send a feedback result.

[0237] Optionally, the indication information indicating whether to further feedback may be displayed when the first communication device notifies the second communication device of specific information that needs to be fed back. For example, in the following, the first communication device transmits a second PPDU to the second communication device, where the second PPDU includes third information for notifying the second communication device. For details, please refer to the following embodiments. Details will not be described in this specification. In this case, the second communication device may feedback the specific information that the first communication device requests to be fed back to the second communication device.

[0238] It should be noted that the first information may include any one of the above information 1 to information 4, or may include various combinations of the above information 1 to information 4, and the combination of information implemented based on individual circumstances in actual application falls within the scope of protection of the present application.

[0239] Furthermore, the first information may be carried in the first PPDU in the following manner: For example, the first information in the first PPDU may include one or more types of information 1 to information 4 above, and each type of information may be indicated by a corresponding bit.

[0240] Mode 1: The first information has only one format and the length of the first information is fixed. Specifically, the first information indicates a specific piece of information 1 to 4, and the length of the bits indicating this specific piece of information is fixed, and the arrangement and combination form between the bits are also fixed. The fixed length facilitates reading and improves the efficiency and accuracy of reading the first PPDU by the first communication device. Optionally, the format and length of the first PPDU are also fixed.

[0241] Optionally, the first information in the first PPDU includes each type of information 1 to information 4 above, where the first information includes 24 bits, where the first to third bits indicate one or more pieces of information in information 1, the fourth to tenth bits indicate one or more pieces of information in information 2, the eleventh to nineteenth bits indicate one or more pieces of information in information 3, and the twentieth to twenty-fourth bits indicate one or more pieces of information in information 4. The second communication device may set the information that needs to be fed back to a first value (e.g., 1) and set the information that does not need to be fed back to a second value (e.g., 0), where the first value and the second value are random and different from each other. Alternatively, the first communication device may request the second communication device to feed back one or more types of information from information 1 to information 4. The second communication device may feed back information requested by the first communication device using a specific first value (e.g., 1), but the second communication device may not feed back information not requested by the first communication device, or may feed back information not requested by the first communication device using any value (different from the first value) or a second value.

[0242] For example, the information included in the first information may be represented in the form of bitmaps, each bitmap may represent one piece of information, each bitmap may include one or more bits, and the length of the bitmaps may be fixed.

[0243] For example, the first PPDU may include second information, i.e., whether the channel variation satisfies a predetermined condition (shortened as channel variation), and the first information in the first PPDU may include a CSI type for channel variation calculation, indication information indicating whether more measurements are needed, and a feedback type. The first PPDU may further include fourth information, i.e., a channel variability degree. As shown in FIG. 8 , in the first PPDU, the channel variation occupies one bit, the CSI type for channel variation calculation is represented using a CSI bitmap and occupies three bits, the indication information indicating whether more measurements are needed occupies one bit, the feedback type occupies one bit, the indication information indicating whether more feedback is needed occupies one bit, and the channel variability degree occupies three bits. The CSI type indicated by the three-bit bitmap is determined, and for example, each bit of the three bits may separately represent the last measured CSI, the average CSI, and the flagged CSI. For example, the CSI type indicated by the three-bit CSI bitmap is determined, and the three bits are 110. This indicates that the CSI type for channel variation calculation includes the previously measured CSI and average CSI, but does not include the flagged CSI. The first communication device may receive the CSI bitmap in which three bits are 110 and determine that the second communication device will calculate the channel variation using the previously measured CSI and average CSI. Optionally, the number of bits set to 1 in the CSI bitmap may be limited to one or more, or may not be limited. For example, when only one bit can be set to 1, this indicates that only one type of CSI can be used when the second communication device calculates the channel variation. The fact that the number of bits set to 1 is not limited indicates that the number of CSI types used when the second communication device calculates the channel variation is not limited. Optionally, the first information in the first PPDU may have only the structure shown in FIG. 8, i.e., the first information only indicates the CSI type for channel variation calculation, indication information indicating whether more measurements are needed, and feedback type.Furthermore, the bits occupied by the CSI type for channel variation calculation, the indication information indicating whether more measurements are needed, and the feedback type can only be arranged and combined in the manner shown in Figure 8.

[0244] In another example, the information included in the first information may be indicated in the form of an index. In a possible implementation, two bits are used to indicate four different types of information (or a combination of four different types of information). In the two-bit index, 00 indicates that the channel variation satisfies a predetermined condition, 01 indicates that the CSI type for the channel variation calculation includes the previously measured CSI, 10 indicates that the CSI type for the channel variation calculation includes the average CSI, and 11 indicates that further feedback is required. It should be noted that the above is merely an example. The number of bits of the index may not be limited to two bits and may include more bits, and more information may be indicated based on the more bits. Details are not provided in this application.

[0245] Manner 2: Different modes correspond to different forms of the first information, i.e., different modes correspond to different first information. In this way, for each mode, information corresponding to that mode is carried. This further helps the first communication device select the second communication device to which the feedback result should be sent. Optionally, the information carried in each mode is different. First PPDUs carrying different first information may be considered different.

[0246] For example, information corresponding to different modes may be conveyed using different bitmaps or different indices.

[0247] For example, in Mode 1, the first PPDU includes Mode 1 indication information, first information, and second information (the second information in this specification is the channel variation described above). In Mode 2, the first PPDU includes Mode 2 indication information, first information, second information, and fourth information (the fourth information in this specification is the channel variability described above). The first information in Mode 1 is different from the first information in Mode 2. The first information in Mode 1 includes a feedback type, and the first information in Mode 2 includes a feedback type and a CSI type for channel variation calculation (this information is represented using a CSI bitmap). As shown in FIG. 9, the indication information for Mode 1 occupies 2 bits, the channel variation occupies 1 bit, and the feedback type of the feedback result occupies 2 bits. In Mode 2, the indication information for Mode 2 occupies 2 bits, the channel variation occupies 1 bit, the CSI bitmap occupies 3 bits, the feedback type occupies 2 bits, and the channel variability occupies 3 bits.

[0248] It should be noted that the above Mode 1 and Mode 2 are merely examples, and many other modes may be configured based on specific applications in relation to this embodiment of the present application, which is not limited in the present application.

[0249] Manner 3: Whether the channel fluctuation exceeds a predefined fluctuation threshold corresponds to different first information. The different first information corresponds to different first PPDUs. In this way, whether the channel fluctuation exceeds a predefined fluctuation threshold (i.e., the second information in the above description) is conveyed with corresponding first information. This further helps the first communication device select the second communication device to send the feedback result to. Optionally, whether the channel fluctuation exceeds a predefined fluctuation threshold may also be considered as a different mode.

[0250] For example, information corresponding to different modes may be conveyed using different bitmaps or different indices.

[0251] For example, when the channel fluctuation exceeds a predetermined fluctuation threshold, the first PPDU includes indication information indicating that the channel fluctuation exceeds the predetermined fluctuation threshold, the first information, and fourth information (the fourth information in this specification is the above-mentioned channel variability). When the channel fluctuation does not exceed the predetermined fluctuation threshold, the first PPDU includes indication information indicating that the channel fluctuation does not exceed the predetermined fluctuation threshold and the first information. When the channel fluctuation exceeds the predetermined fluctuation threshold, the first information includes a feedback type and a CSI type for channel fluctuation calculation (this information is represented using a CSI bitmap), and when the channel fluctuation does not exceed the predetermined fluctuation threshold, the first information includes a CSI bitmap. As shown in Figure 10, when the channel fluctuation exceeds the predetermined fluctuation threshold, the indication information indicating that the channel fluctuation exceeds the predetermined fluctuation threshold occupies 1 bit, the channel variability occupies 3 bits, the feedback type occupies 2 bits, and the CSI bitmap occupies 3 bits. When the channel fluctuation does not exceed the predetermined fluctuation threshold, the indication information indicating that the channel fluctuation does not exceed the predetermined fluctuation threshold occupies 1 bit, and the CSI bitmap occupies 3 bits.

[0252] It can be understood that Figures 8, 9, and 10 are merely examples of the first PPDU and are not limitations on the first PPDU.

[0253] Manner 4: The first information may be conveyed based on an instruction of the first communication device.

[0254] For example, a first communication device transmits a second PPDU and a second communication device receives the second PPDU, where the second PPDU includes third information, and the third information is used to request or notify the first information.

[0255] At S702, the second communication device may actively transmit the first PPDU to the first communication device, or the second communication device may transmit the first PPDU to the first communication device based on an instruction from the first communication device.

[0256] Optionally, the third information may include, but is not limited to, at least one of the following types of information: CSI measurement quantity indication information required for channel variation calculation, CSI type for channel variation calculation, information on the rule for channel variation calculation, feedback suggestion parameters, or indication information for clearing CSI.

[0257] The indication information for clearing the CSI instructs the second communication device to clear the stored CSI. Optionally, in the second communication device, the currently measured CSI may be used as the first measured CSI, and CSI measured before the currently measured CSI is not taken into account when calculating the channel variation.

[0258] The third PPDU may be a feedback request in the reporting phase or may be a frame transmitted before the feedback request, such as a frame in the setup phase or a frame in the measurement phase (e.g., NDPA).

[0259] Optionally, the third information is carried in a MAC frame of the third PPDU, i.e., the data field of the third PPDU includes the MAC frame, and the MAC frame includes the third information. Alternatively, the third information is optionally carried in a PHY preamble of the third PPDU. Alternatively, the third information is optionally carried in a frame whose type is a trigger frame or a polling frame, for example, in a Common Info field or a User Info field of the trigger frame.

[0260] S703: The first communication device determines, based on the first information in the first PPDU, whether to trigger the second communication device to send a feedback result.

[0261] Optionally, at S703, the first communication device may determine whether to trigger the second communication device to send a feedback result based on the first information and the second information. Alternatively, the first communication device may determine whether to trigger the second communication device to send a feedback result based on the first information and the fourth information. Alternatively, the first communication device may determine whether to trigger the second communication device to send a feedback result based on the first information, the second information, and the fourth information.

[0262] In this step, the first communication device not only determines whether to trigger the second communication device to send a feedback result based on the result of whether the channel fluctuation exceeds a predetermined fluctuation threshold, but also determines whether to trigger the second communication device to send a feedback result based on the first information, and selects the second communication device to send the feedback result, thereby improving the accuracy of the judgment.

[0263] Optionally, the method provided in this embodiment of the present application further includes S704, where the first communication device transmits a second PPDU.

[0264] In response, the second communication device receives a second PPDU, which is used to trigger the second communication device to send a feedback result.

[0265] The first communication device may receive first PPDUs transmitted by one or more second communication devices, and the first communication device may select from the second communication devices that trigger transmission of a feedback result based on the one or more first PPDUs and select the second communication devices that trigger transmission of the feedback result, and transmit second PPDUs to the second communication devices that trigger transmission of the feedback result and not transmit the second PPDU to the second communication devices that do not trigger transmission of the feedback result.

[0266] The second PPDU may be or is similar to a feedback request frame, a feedback trigger frame, or a polling frame.

[0267] In a possible case, if the first information includes information indicating that further feedback is not required (not requested), the first communication device may not trigger the second communication device to transmit a feedback result, i.e., the second communication device may not transmit a second PPDU.

[0268] Optionally, the method provided in this embodiment of the present application further includes S705, where the second communication device sends a feedback result.

[0269] In response, the first communication device receives the feedback result.

[0270] The feedback result may be a channel measurement result. Alternatively, the feedback result may be information instructing the first communication device to measure the channel. That is, the first communication device executes a processing process in a receiver or responder, e.g., performs channel measurement, transmits a first PPDU, or transmits the feedback result, and the second communication device executes a processing process in a transmitter or initiator, e.g., triggers channel measurement, transmits a second PPDU, and receives the feedback result. In this way, the first communication device does not need to wait for the second communication device to feedback the channel measurement result, and the first communication device performs channel measurement, allowing the channel measurement result to be obtained in a more timely manner. That is, the first communication device and the second communication device exchange roles.

[0271] The information instructing the first communication device to measure the channel may be an NDP.

[0272] The second communication device that receives the second PPDU transmits a feedback result. Optionally, the second communication device that does not receive the second PPDU may not transmit a feedback result, or the second communication device may actively transmit a feedback result.

[0273] In this embodiment of the present application, the first information is used to select the second communication device to send the feedback result. Therefore, the first communication device can more accurately determine one or more second communication devices to be triggered based on the received first information, and the triggered one or more second communication devices will send the feedback result. In this way, the accuracy of channel measurement can be improved.

[0274] FIG. 11 shows a possible sensing process according to an embodiment of the present application. In the measurement phase, the transmitter sends NDPA and NDP to instruct one or more receivers to perform channel measurement. In the reporting phase, the transmitter sends a feedback request to request feedback of channel variations, and receiver 1 sends a feedback response, where the feedback response carries first information (of receiver 1), and receiver 2 also sends a feedback response, where the feedback response carries first information (of receiver 2). The transmitter may send feedback triggers to both receiver 1 and receiver 2, and receiver 1 and receiver 2 return channel measurement results. In FIG. 11, the transmitter selects a receiver to send feedback results based on the first information. This helps improve the accuracy of the channel measurement. Optionally, the feedback response of receiver 2 may carry Not Met information, and receiver 2 may still be triggered to send feedback results. This helps improve the accuracy of the channel measurement.

[0275] In the feedback method provided in this embodiment of the present application, the first communication device may transmit third information, which is used to request or notify the first information, and the first information is used to select the second communication device to transmit the feedback result. Thus, the first communication device can more accurately determine one or more second communication devices to be triggered, and the triggered one or more second communication devices will transmit the feedback result to improve the accuracy of channel measurement.

[0276] Figure 12 shows another feedback method according to an embodiment of the present application. The similarities between Figure 12 and Figure 7 will not be repeated. This feedback method includes the following steps:

[0277] S1201: The first communication device generates a second PPDU.

[0278] S1202: The first communication device transmits a second PPDU.

[0279] In response, the second communication device receives the second PPDU.

[0280] The second PPDU includes third information, which is used to request or notify the first information. The first information is information related to channel measurement. Another type of information related to channel measurement, i.e., the first information, is different from the information indicating the channel measurement result and the channel variation.

[0281] For example, the second PPDU may be a feedback request in the reporting phase, or may be a frame transmitted before the feedback request, such as a frame in the setup phase or a frame in the measurement phase (e.g., NDPA).

[0282] Optionally, the third information is carried in a MAC frame of the second PPDU. Alternatively, the third information is optionally carried in a PHY preamble of the second PPDU. Alternatively, the third information is optionally carried in a frame whose type is a trigger frame or a polling frame, for example, in a common information field or a user information field of the trigger frame.

[0283] Optionally, the third information may include, but is not limited to, at least one of the following types of information: CSI measurement quantity indication information required for channel variation calculation, CSI type for channel variation calculation, information on the rule for channel variation calculation, feedback suggestion parameters, or indication information for clearing CSI.

[0284] The third information may be carried in the second PPDU in the following manner: See the first PPDU above for similarities, and details will not be repeated here.

[0285] Mode 1: The tertiary information has only one form, and the length of the tertiary information is fixed. For example, the tertiary information may be carried in the form of a bitmap or an index.

[0286] Manner 2: Different modes correspond to different forms of the second PPDU. For example, information corresponding to different modes may be carried using different bitmaps or different indicators.

[0287] Manner 3: Different information may be conveyed depending on whether the channel fluctuation exceeds a predetermined fluctuation threshold, i.e., the different information corresponds to different forms of the second PPDU. For example, information corresponding to different modes may be conveyed using different bitmaps or different indicators.

[0288] Requesting the first information means requesting the second communication device to feed back the first information. For the second communication device, the third information means that the second communication device needs to feed back the first information. However, the channel measurement process and channel measurement results of the second communication device are not affected. The first communication device may selectively trigger the second communication device to transmit the first information based on the first information fed back by the second communication device to improve the accuracy of the determination. For example, the first communication device may determine that channel fluctuations calculated based on CSI measured for the first time can better meet currently required channel measurement requirements (e.g., measuring objects moving at a slow speed). The first communication device may request that the second communication device determine whether the second communication device used CSI measured for the first time when calculating the channel fluctuations, and may request that the CSI type for the channel fluctuation calculation be CSI measured for the first time. In this case, the second communication device feedbacks whether the CSI type for the channel fluctuation calculation is CSI measured for the first time. For example, when the CSI type for channel fluctuation calculation is the first measured CSI, the value of one bit of the CSI used for channel fluctuation calculation is 1, and when the CSI type for channel fluctuation calculation is not the first measured CSI, the value of one bit of the first measured CSI is 0.

[0289] Notifying the first information means notifying the second communication device of the first information. For the second communication device, the notification of the first information may affect input parameters and / or output parameters used by the second communication device to calculate channel variation, and may further affect the channel variation calculated by the second communication device. Therefore, the second communication device may calculate more accurate channel variation. The first communication device may more accurately determine whether to trigger the second communication device to transmit a feedback result when channel variation occurs. For example, the first communication device may consider that channel variation calculated based on CSI measured for the first time can better satisfy currently required channel measurement requirements (e.g., measuring a slowly moving object), and the first communication device may notify that the CSI type for channel variation calculation is the first-measured CSI. In this case, the second communication device calculates the channel variation based on the first-measured CSI. Optionally, the CSI type for channel variation calculation fed back by the second communication device is the first-measured CSI.

[0290] Optionally, the information in the third information used to request or notify information related to channel measurement may be that shown in Table 4.

[0291] [Table 4-1] [Table 4-2] [Table 4-3]

[0292] S1203: The second communication device transmits the first PPDU.

[0293] In response, the first communication device receives the first PPDU.

[0294] Optionally, the second communication device may also feed back the first PPDU in an existing feedback manner, for example, the first PPDU only includes whether the channel fluctuation exceeds a predetermined fluctuation threshold.

[0295] Alternatively, the second communication device may feed back a first PPDU in a new feedback manner. The first PPDU may include first information. Optionally, the first information may include, but is not limited to, at least one of the following types of information: CSI measurement quantity indication information required for channel variation calculation, CSI type for channel variation calculation, information on a rule for channel variation calculation, or feedback suggestion parameters.

[0296] For example, if the third information is used to request the first information, the second communication device needs to add the requested first information to the first PPDU. For example, if the CSI type used for the channel variation calculation requested by the third information is the first-measured CSI, the second communication device adds the first-measured CSI to the first information of the first PPDU. If the second communication device calculates the channel variation based on the first-measured CSI, the value of the bit for the first-measured CSI in the first information is 1. If the second communication device does not calculate the channel variation based on the first-measured CSI, the value of the bit for the first-measured CSI in the first information is 0. In this way, the first communication device may determine whether the second communication device will calculate the channel variation using the first-measured CSI based on the first information.

[0297] For example, if the third information is used to notify the first information, the second communication device does not need to add the notified first information to the first PPDU. For example, if the third information notifies that the CSI type for channel fluctuation calculation is the first-measured CSI, the second communication device calculates the channel fluctuation based on the first-measured CSI. In this case, the second communication device may add the first-measured CSI to the first information. Alternatively, the second communication device may not add the first-measured CSI to the first information, or may not feed back the first information, for example, may feed back only the first information.

[0298] Optionally, the method provided in this embodiment of the present application further includes S1204, where the first communication device transmits a third PPDU based on the first information in the first PPDU.

[0299] In response, the second communication device receives the third PPDU.

[0300] Optionally, the method provided in this embodiment of the present application further includes S1205, in which the second communication device sends a feedback result.

[0301] In response, the first communication device receives the feedback result.

[0302] The second communication device that receives the third PPDU may send a feedback result. Optionally, the second communication device that does not receive the third PPDU may not send a feedback result, or may actively send a feedback result. For specific processes, please refer to Figure 7. Similarities will not be repeated.

[0303] In this embodiment of the present application, the first communication device may transmit third information, which may be used to request or notify the first information, and the first information is used to select the second communication device to transmit the feedback result. Thus, the first communication device can more accurately determine one or more second communication devices to be triggered, and the triggered one or more second communication devices will transmit the feedback result to improve the accuracy of the channel measurement.

[0304] FIG. 13 shows a possible sensing process according to an embodiment of the present application. In the measurement phase, the transmitter sends NDPA and NDP to instruct one or more receivers to perform channel measurement. In the reporting phase, the transmitter sends a feedback request, where the feedback request includes third information. Receiver 1 and receiver 2 send feedback responses. The transmitter sends a feedback trigger to both receiver 1 and receiver 2, and receiver 1 and receiver 2 return channel measurement results. In FIG. 13, the transmitter selects a receiver to send feedback results to based on the first information. This helps improve the accuracy of the channel measurement. Optionally, even if receiver 2's feedback response carries Not Met information, receiver 2 may still be triggered to send feedback results. This helps improve the accuracy of the channel measurement.

[0305] In this embodiment of the present application, unless otherwise specified or there is no logical contradiction, the terms and / or descriptions between different embodiments are consistent and can be cross-referenced, and the technical features of different embodiments may be combined based on their internal logical relationships to form a new embodiment.

[0306] In the above embodiments, it may be understood that the methods and / or steps performed by the first communication device may be performed by components (e.g., chips or circuits) that may be used within the first communication device, and that the methods and / or steps performed by the second communication device may be performed by components that may be used within the second communication device.

[0307] In the above embodiments provided in the present application, the methods provided in the embodiments of the present application are described separately in terms of the interaction between the first communication device and the second communication device. To implement the functions of the methods provided in the embodiments of the present application, the first communication device and the second communication device may include hardware structures and / or software modules, and may implement the above functions in the form of a hardware structure, a software module, or a combination of a hardware structure and a software module. Whether the functions among the above functions are performed using a hardware structure, a software module, or a combination of a hardware structure and a software module depends on the individual application and design constraints of the technical solution.

[0308] Hereinafter, a communication device for implementing the above method of the embodiment of the present application will be described with reference to the accompanying drawings. Therefore, all the above content can be used in the following embodiment. The repeated content will not be described again.

[0309] FIG. 14 is a possible representation of a communication device according to an embodiment of the present application. The communication device 1400 may be configured to perform functions or steps performed by the first communication device or the second communication device in the above-described method embodiments. Optionally, the communication device may include a processing unit 1401 and a transceiver unit 1402. Optionally, the communication device may further include a storage unit. The storage unit may be configured to store instructions (codes or programs) and / or data. The processing unit 1401 and the transceiver unit 1402 may be coupled to the storage unit. For example, the processing unit 1401 may read the instructions (codes or programs) and / or data from the storage unit to perform the corresponding method. The above units may be independently located or partially or fully integrated.

[0310] In some possible implementations, the communication device 1400 may similarly implement the behavior and functions of the first communication device in the above-described method embodiments. For example, the communication device 1400 may be an AP or a component (e.g., a chip or circuit) used within an AP. The transceiver unit 1402 may be configured to perform all receiving or transmitting operations performed by the first communication device in the embodiment shown in FIG. 7 or FIG. 12. For example, the transceiver unit 1402 may be configured to perform S701 of the embodiment shown in FIG. 7 and / or correspond to another process of the technology described herein. The processing unit 1401 is configured to perform all operations other than transmitting and receiving operations performed by the first communication device in the embodiment shown in FIG. 7 or FIG. 12. For example, the processing unit 1401 may be configured to generate a second PPDU at S702 of the embodiment shown in FIG. 7 and / or correspond to another process of the technology described herein.

[0311] For example, the transceiver unit 1402 is configured to receive a first PPDU, where the first PPDU includes first information, the first information including at least one of the following types of information: CSI measurement quantity indication information required for channel variation calculation, CSI type for channel variation calculation, information about a rule for channel variation calculation, or a feedback suggestion parameter, where the feedback suggestion parameter indicates a suggested feedback form.

[0312] The processing unit 1401 is configured to determine, based on the first information, whether to trigger the second communication device to send a feedback result.

[0313] Optionally, the transceiver unit 1402 is further configured to transmit a second PPDU, where the second PPDU includes third information, and the third information is used to request or notify the first information.

[0314] In some possible implementations, the communication device 1400 may similarly implement the behavior and functions of the second communication device in the above-described method embodiments. For example, the communication device 1400 may be an STA or a component (e.g., a chip or circuit) used within an STA. The transceiver unit 1402 may be configured to perform all receiving or transmitting operations performed by the second communication device in the embodiment shown in FIG. 7 or FIG. 12. For example, the transceiver unit 1402 may be configured to perform S701 of the embodiment shown in FIG. 7 and / or correspond to another process of the technology described herein. The processing unit 1401 is configured to perform all operations other than transmitting and receiving operations performed by the second communication device in the embodiment shown in FIG. 7 or FIG. 12. For example, the processing unit may be configured to generate a first PPDU in S701 of the embodiment shown in FIG. 7 and / or correspond to another process of the technology described herein.

[0315] For example, the processing unit 1401 is configured to generate a first PPDU, where the first PPDU includes first information, and the first information includes at least one of the following types of information: CSI measurement quantity indication information required for channel variation calculation, CSI type for channel variation calculation, information on a rule for channel variation calculation, or feedback suggestion parameter, where the feedback suggestion parameter indicates a suggested feedback form.

[0316] The transceiver unit 1402 is configured to transmit a first PPDU.

[0317] Optionally, the transceiver unit 1402 is further configured to receive a second PPDU, the second PPDU including third information, which is used to request the first information or notify the first information.

[0318] In an optional manner, the third information includes at least one of the following types of information: CSI measurement quantity indication information required for channel variation calculation, CSI type for channel variation calculation, information on rules for channel variation calculation, feedback suggestion parameters, or indication information for clearing CSI.

[0319] In an optional manner, the first PPDU further includes second information, where the second information indicates whether the channel fluctuation exceeds a specified fluctuation threshold.

[0320] In an optional manner, the CSI measurement quantity indication information required for the channel variation calculation includes at least one of the following types: indication information indicating whether more measurements are required, the total quantity of measurements, or the remaining quantity of measurements.

[0321] In an optional manner, the CSI type for the channel variation calculation includes at least one of the following types: currently measured CSI, CSI for which the measurement time exceeds a specified time threshold, CSI for which the quantity of measurements exceeds a specified quantity threshold, previously measured CSI, first measured CSI, average CSI, numbered CSI, or flagged CSI.

[0322] In an optional manner, the feedback suggestion parameter includes at least one of the following types: a feedback type, a number of subcarriers in a subcarrier group, a number of bits of codebook information, or a number of bits of CSI.

[0323] In an optional manner, the first information is carried in a MAC frame of the first PPDU, or the first information is carried in a PHY preamble of the first PPDU.

[0324] It should be noted that the communication device 1400 can be configured to perform the above method embodiments. For specific steps, descriptions and corresponding advantageous effects, please refer to the above method embodiments. Details will not be repeated in this specification.

[0325] It should be understood that the processing unit 1401 in this embodiment of the present application may be implemented by a processor / processing circuit or circuit components related to a processor / processing circuit, and the transceiver unit 1402 may be implemented by a transceiver / transceiver interface or circuit components related to a transceiver / transceiver interface or communication interface.

[0326] 15 is a possible representation of a communication device according to an embodiment of the present application. The communication device 1500 may include a processor 1501 and a transceiver 1505, and may optionally further include a memory 1502. The communication device may be used as a device for transmitting trigger frames and PPDUs of the present application, or may be used as a device for receiving trigger frames and PPDUs of the present application.

[0327] The transceiver 1505 may be referred to as a transceiver unit, transceiver machine, or transceiver circuit, and is configured to perform a transceiver function. The transceiver 1505 may include a receiver machine and a transmitter machine. The receiver machine may be referred to as a receiver or receiver circuit, and is configured to perform a receiving function. The transmitter machine may be referred to as a transmitter or transmitter circuit, and is configured to perform a transmitting function.

[0328] The memory 1502 may store computer programs, software codes, or instructions 1504, which may also be referred to as firmware. The processor 1501 may control the MAC layer or the PHY layer by executing the computer programs, software codes, or instructions 1503 or by calling the computer programs, software codes, or instructions 1504 stored in the memory 1502 to implement the PPDU transmission methods provided in the following embodiments of the present application. The processor 1501 may be a central processing unit (CPU), and the memory 1502 may be, for example, a read-only memory (ROM) or a random access memory (RAM).

[0329] The processor 1501 and transceiver 1505 described herein may be implemented in an integrated circuit (IC), an analog IC, a radio frequency integrated circuit (RFIC), a mixed signal IC, an application-specific integrated circuit (ASIC), a printed circuit board (PCB), an electronic device, and the like.

[0330] The communication device 1500 may further include an antenna 1506. The modules included in the communication device 1500 are merely examples for purposes of illustration and are not limiting of the present application.

[0331] As described above, the communication device 1500 described in the above embodiment may be an AP or a STA. However, the scope of the communication device described in this application is not limited thereto, and the structure of the communication device is not limited to the structure in FIG. 15 .

[0332] An AP may be an AP with multiple antennas / radio frequencies or an AP with a single antenna / radio frequency, where the antenna / radio frequency is configured to transmit / receive data packets. In an implementation, the antenna or radio frequency portion of the AP may be separate from the main body of the AP, i.e., may be located remotely. In an implementation, an STA may be an STA with a single antenna / radio frequency, an STA with multiple antennas / radio frequencies, or a device with more than two antennas. The antenna / radio frequency is configured to transmit / receive data packets. In an implementation, the antenna or radio frequency portion of the STA may be separate from the main body of the STA, i.e., may be located remotely.

[0333] Alternatively, the communication device of the present application may be a standalone device or part of a larger device. For example, the communication device may be implemented in the following forms: (1) An independent integrated circuit IC, chip, chip system, or subsystem; (2) a set of one or more ICs, which may optionally include a memory component for storing data and instructions; (3) a module capable of being embedded in another device; (4) a receiver, intelligent terminal, wireless device, handheld device, mobile unit, vehicle-mounted device, cloud device, or artificial intelligence device, or (5) other.

[0334] When the communication device is implemented in the form of a chip or a chip system, please refer to the schematic diagram of the chip structure shown in Figure 16. The chip shown in Figure 16 includes a processor 1601 and an interface 1602. There may be one or more processors 1601 and multiple interfaces 1602. The interface 1602 is configured to receive and transmit signals. Optionally, the chip or chip system may also include a memory 1603. The memory 1603 is configured to store program instructions and data required for the chip or chip system.

[0335] The embodiments of the present application do not limit the protection scope and applicability of the claims. Those skilled in the art may adaptively change the functions and deployments of the elements of the present application, or omit, replace, or add various processes or components as appropriate, without departing from the scope of the embodiments of the present application.

[0336] The embodiments of the present application further provide a computer-readable storage medium, which stores a computer program, and when the computer-readable storage medium is executed by a computer, performs the functions of the above-described method embodiments.

[0337] An embodiment of the present application further provides a computer program product, which, when executed by a computer, performs the functions of the above method embodiments.

[0338] An embodiment of the present application further provides a chip system. The chip system includes a processor and an interface configured to support a communication transmission device to perform the functions of an access point or station in the above-described method embodiments, such as determining or processing at least one of data and information in the above-described method. In a possible design, the chip system further includes a memory configured to store instructions and data required for the above-described communication device. The chip system may include a chip, or may include a chip and another discrete component.

[0339] An embodiment of the present application provides a functional entity, which is configured to implement the above feedback method.

[0340] It should be further understood that the terms "first," "second," "third," "fourth," and various numbers used herein are merely used for distinction purposes for ease of description and are not intended to limit the scope of the present application.

[0341] It should be understood that the term "and / or" herein describes only an associative relationship between related objects and represents three possible relationships. For example, A and / or B may represent three cases: A only exists; both A and B exist; and B only exists. Furthermore, the character " / " herein generally indicates an "or" relationship between related objects.

[0342] It should be understood that the sequence numbers of the above processes do not imply the order of execution in various embodiments of the present application, and the order of execution of the processes should be determined by the functions and internal logic of the processes, and should not be construed as any limitation on the implementation process of the embodiments of the present application.

[0343] Those skilled in the art may realize that the units and algorithm steps, in combination with the examples described in the embodiments disclosed herein, may be implemented by electronic hardware or a combination of computer software and electronic hardware. Whether these functions are performed by hardware or software depends on the individual application and design constraints of the technical solution. Those skilled in the art may use various methods to implement the described functions for each individual application, and such implementations shall not be deemed to depart from the scope of the present application.

[0344] For convenience and simplicity of description, those skilled in the art can clearly understand that for the detailed operation processes of the above systems, devices and units, please refer to the corresponding processes in the above method embodiments, and the details will not be repeated in this specification.

[0345] In some embodiments provided herein, it should be understood that the disclosed systems, devices, and methods may be implemented in other ways. For example, the device embodiments described are merely examples. For example, the division into units is merely a logical division of functions, and other divisions may be used in actual implementation. For example, multiple units or components may be combined or integrated to form another system, or some features may be ignored or not implemented. Furthermore, the shown or described mutual couplings or direct couplings or communication connections may be implemented using some interfaces. Indirect couplings or communication connections between devices or units may be implemented in electronic, mechanical, or other forms.

[0346] The units described as separate parts may or may not be physically separated, and the parts shown as units may or may not be physical units, and may be located in one location or distributed over multiple network units. Some or all of these units may be selected according to actual requirements to achieve the objectives of the solutions of the embodiments.

[0347] Furthermore, the functional units in the embodiments of the present application may be integrated into a single processing unit, each of the units may exist physically alone, or two or more units may be integrated into a single unit.

[0348] When functions are implemented in the form of software functional units and sold or used as independent products, these functions may be stored in a computer-readable storage medium. Based on this understanding, the technical solutions of the present application may essentially be implemented in the form of a software product, or a portion of the technical solutions may contribute to the prior art. The software product may be stored in a storage medium and include instructions that instruct a computer device (which may be a personal computer, a server, or a network device) to perform all or part of the steps of the methods described in the embodiments of the present application. The storage medium may include any medium that can store program code, such as a USB flash drive, a removable hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk, or an optical disk.

[0349] The order of steps in the methods of the embodiments of the present application may be adjusted, combined or removed based on actual requirements.

[0350] The modules in the device of the present embodiment can be combined, divided and deleted based on actual requirements.

[0351] In conclusion, the above embodiments are merely for illustrating the technical solutions of the present application, and are not intended to limit the present application. Although the present application has been described in detail with reference to the above embodiments, it should be understood that those skilled in the art may still make modifications to the technical solutions described in the above embodiments, or make equivalent substitutions for some technical features thereof, without departing from the scope of the technical solutions of the embodiments of the present application.

Claims

1. 1. A feedback method comprising: receiving, by a first communication device, a first physical layer protocol data unit (PPDU), the first PPDU including first information, the first information including at least one of the following types of information: channel state information (CSI) measurement quantity indication information required for channel variation calculation, a CSI type for the channel variation calculation, information about a rule for the channel variation calculation, or a feedback suggestion parameter, the feedback suggestion parameter indicating a suggested feedback form; determining, by the first communication device, whether to trigger a second communication device to send a feedback result based on the first information; Feedback methods, including:

2. The method of claim 1 , wherein the first PPDU further includes fourth information, the fourth information indicating channel variability.

3. 3. The method of claim 1, wherein the first PPDU further includes second information, the second information indicating whether a channel fluctuation exceeds a specified fluctuation threshold.

4. Prior to the step of receiving a first PPDU by the first communication device, the method further comprises: transmitting, by the first communication device, a second PPDU, the second PPDU including third information, the third information being used to request the first information or to inform the first information; The method of any one of claims 1 to 3, further comprising:

5. 5. The method of claim 4, wherein the third information includes at least one of the following types: indication information of the CSI measurement quantity required for the channel variation calculation, the CSI type for the channel variation calculation, the information about the rule for the channel variation calculation, the feedback suggestion parameters, or indication information for clearing CSI.

6. 6. The method according to claim 1, wherein the CSI measurement quantity indication information required for the channel variation calculation comprises at least one of the following types: an indication of whether more measurements are required, a total number of measurements, or a remaining number of measurements.

7. 7. The method of claim 1, wherein the CSI type for the channel variation calculation includes at least one of the following types: currently measured CSI, CSI whose measurement time exceeds a specified time threshold, CSI whose measurement quantity exceeds a specified quantity threshold, previously measured CSI, first measured CSI, average CSI, numbered CSI, or flagged CSI.

8. 8. The method according to claim 1, wherein the feedback suggestion parameters include at least one of the following types: a feedback type, a number of subcarriers in a subcarrier group, a number of bits of codebook information, or a number of bits of CSI.

9. 1. A feedback method comprising: generating, by a second communication device, a first physical layer protocol data unit (PPDU), the first PPDU including first information, the first information including at least one of the following types of information: channel state information (CSI) measurement quantity indication information required for channel variation calculation, a CSI type for the channel variation calculation, information about a rule for the channel variation calculation, or a feedback suggestion parameter, the feedback suggestion parameter indicating a suggested feedback form; transmitting, by the second communication device, the first PPDU; Feedback methods, including:

10. 10. The method of claim 9, wherein the first PPDU further includes fourth information, the fourth information indicating channel variability.

11. 11. The method of claim 9 or 10, wherein the first PPDU further includes second information, the second information indicating whether a channel fluctuation exceeds a specified fluctuation threshold.

12. Prior to the step of transmitting a first PPDU by the second communication device, the method further comprises: transmitting, by the second communication device, a second PPDU, the second PPDU including third information, the third information being used to request the first information or to inform the first information; The method of any one of claims 9 to 11, further comprising:

13. 13. The method of claim 12, wherein the third information includes at least one of the following types: indication information of the CSI measurement quantity required for the channel variation calculation, the CSI type for the channel variation calculation, the information about the rule for the channel variation calculation, the feedback suggestion parameters, or indication information for clearing CSI.

14. 14. The method according to claim 9, wherein the indication of the number of CSI measurements required for the channel variation calculation comprises at least one of the following types: an indication of whether more measurements are required, a total number of measurements, or a remaining number of measurements.

15. 15. The method of claim 9, wherein the CSI type for the channel variation calculation includes at least one of the following types: currently measured CSI, CSI whose measurement time exceeds a specified time threshold, CSI whose measurement quantity exceeds a specified quantity threshold, previously measured CSI, first measured CSI, average CSI, numbered CSI, or flagged CSI.

16. 16. The method according to any one of claims 9 to 15, wherein the feedback suggestion parameters comprise at least one of the following types: feedback type, number of subcarriers in a subcarrier group, number of bits of codebook information, or number of bits of CSI.

17. A communication device, a transceiver unit for receiving a first physical layer protocol data unit (PPDU) by a first communication device, the first PPDU including first information, the first information including at least one of the following types of information: channel state information (CSI) measurement quantity indication information required for channel variation calculation, a CSI type for the channel variation calculation, information about a rule for the channel variation calculation, or a feedback suggestion parameter, the feedback suggestion parameter indicating a suggested feedback form; a processing unit for determining, by the first communication device, whether to trigger a second communication device to send a feedback result based on the first information; 2. A communication device comprising:

18. 20. The apparatus of claim 17, wherein the first PPDU further includes fourth information, the fourth information indicating channel variability.

19. 19. The apparatus of claim 17 or 18, wherein the first PPDU further includes second information, the second information indicating whether channel fluctuation exceeds a specified fluctuation threshold.

20. The transceiver unit a transceiver unit transmitting a second PPDU, the second PPDU including third information, the third information being used to request the first information or to notify the first information; 20. The apparatus of any one of claims 17 to 19, comprising:

21. 21. The apparatus of claim 17, wherein the third information comprises at least one of the following types: indication information of the CSI measurement quantity required for the channel variation calculation, the CSI type for the channel variation calculation, the information about the rule for the channel variation calculation, the feedback suggestion parameters, or indication information for clearing CSI.

22. 22. The apparatus of claim 17, wherein the CSI measurement quantity indication information required for the channel variation calculation comprises at least one of the following types: an indication of whether more measurements are required, a total number of measurements, or a remaining number of measurements.

23. 23. The apparatus of claim 17, wherein the CSI type for the channel variation calculation includes at least one of the following types: currently measured CSI, CSI whose measurement time exceeds a specified time threshold, CSI whose measurement quantity exceeds a specified quantity threshold, previously measured CSI, first measured CSI, average CSI, numbered CSI, or flagged CSI.

24. 24. The apparatus of claim 17, wherein the feedback suggestion parameters include at least one of the following types: feedback type, number of subcarriers in a subcarrier group, number of bits of codebook information, or number of bits of CSI.

25. A communication device, a processing unit for generating a first physical layer protocol data unit (PPDU) by a first communication device, the first PPDU including first information, the first information including at least one of the following types of information: channel state information (CSI) measurement quantity indication information required for channel variation calculation, a CSI type for the channel variation calculation, information about a rule for the channel variation calculation, or a feedback suggestion parameter, the feedback suggestion parameter indicating a suggested feedback form; a transceiver unit for transmitting the first PPDU; 2. A communication device comprising:

26. 26. The apparatus of claim 25, wherein the first PPDU further includes fourth information, the fourth information indicating channel variability.

27. 27. The apparatus of claim 25 or 26, wherein the first PPDU further includes second information, the second information indicating whether channel fluctuation exceeds a specified fluctuation threshold.

28. The foregoing is a transceiver unit for receiving a second PPDU by the first communication device, the second PPDU including third information, the third information being used to request the first information or to notify the first information; 28. The apparatus of any one of claims 25 to 27, further comprising:

29. 29. The apparatus of claim 28, wherein the third information includes at least one of the following types: indication information of the CSI measurement quantity required for the channel variation calculation; the CSI type for the channel variation calculation; the information about the rule for the channel variation calculation; the feedback suggestion parameter; or indication information for clearing CSI.

30. 30. The apparatus of claim 25, wherein the indication of the number of CSI measurements required for the channel variation calculation comprises at least one of the following types: an indication of whether more measurements are required, a total number of measurements, or a remaining number of measurements.

31. 31. The apparatus of claim 25, wherein the CSI type for the channel variation calculation includes at least one of the following types: currently measured CSI, CSI whose measurement time exceeds a specified time threshold, CSI whose measurement quantity exceeds a specified quantity threshold, previously measured CSI, first measured CSI, average CSI, numbered CSI, or flagged CSI.

32. 32. The apparatus of claim 25, wherein the feedback suggestion parameters include at least one of the following types: feedback type, number of subcarriers in a subcarrier group, number of bits of codebook information, or number of bits of CSI.

33. 1. A communications device comprising a processor and a memory, the processor coupled to the memory; the memory stores a computer program; A communications device, wherein the processor is configured to execute the computer program stored in the memory to enable the device to perform the method of any one of claims 1 to 16.

34. A computer readable storage medium comprising a computer program, which, when run on a computer, performs the method of any one of claims 1 to 16.

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