Method for probing antenna channel, device and data carrier

Abstract

FIELD: wireless communication.SUBSTANCE: first communication device transmits to the second communication device a first frame, which contains first indicator information indicating to the second communication device to perform probing of the transmitting antenna channel, and transmits to the second communication device a first physical protocol data unit (PPDU). The first PPDU is a null data packet (NDP). The first PPDU is used by the second device to perform channel probing of the transmit antenna. The first PPDU contains a first identifier field that indicates the identifier of the first set of transmit antennas.EFFECT: ensuring the correct selection of an antenna by a communication device based on the results of probing an antenna channel in a large-scale antenna scenario.32 cl, 27 dwg

Description

[0001] Cross-reference to related application

[0002] This application claims priority to Chinese Patent Application No. 202111295867.0, filed with the National Intellectual Property Administration of China on November 3, 2021, and entitled “ANTENNA CHANNEL SOUNDING METHOD, APPARATUS, AND STORAGE MEDIUM,” which is incorporated herein by reference in its entirety.

[0003] Field of technology to which the invention relates

[0004] This application relates to the field of communications and, in particular, to a method for probing an antenna channel, a device and a data carrier.

[0005] Technology Level

[0006] Wireless local area network (WLAN) has evolved from the 802.11a / b / g, 802.11n, and 802.11ac standards to the 802.11ax standard. The 802.11a / b / g standard only supports single spatial streams but does not support multiple-input multiple-output (MIMO). The 802.11n standard supports MIMO with a maximum of four spatial-temporal streams. The 802.11ac and 802.11ax standards support a maximum of eight spatial-temporal streams. The next-generation 802.11be standard is discussed based on the 802.11ax standard, and the maximum number of space-time streams is further increased to 16. For space-time streams (STS), both different spatial streams (SS) and space-time block coding (STBC) in the time dimension are considered.When STBC is not used on the transmit side, spatio-temporal streams can also be referred to as spatial streams. The 802.11be standard specifies that STBC is not used, and therefore spatio-temporal streams can be uniformly referred to as spatial streams.

[0007] To support multiple spatial streams, a device must include multiple radio frequency chains (RF chains). In some implementations, the device may be equipped with more antennas (or, more specifically, antenna elements) than RF chains and may select a set of antennas (or antenna pattern) in accordance with an antenna selection procedure for data transmission, thereby further improving transmission performance. For example, by selecting an antenna pattern, it is possible to reduce the number of equivalent channel conditions on the transmitting and receiving sides, improve the equivalent channels, increase the transmitted spatial streams, and increase system throughput.

[0008] In some antenna selection procedures, a device can select an antenna set based on the results of antenna channel sounding corresponding to different antenna sets (or antenna patterns). However, the introduction of more spatial streams means the introduction of more antennas, and traditional technology is only applicable to the 802.11n standard and supports an antenna selection procedure with a maximum of four RF chains, eight antennas, and 16 antenna sets. Furthermore, the 802.11be standard must include 16 spatial streams and support a maximum of 16 RF chains. In addition, MIMO technology uses more antennas. Therefore, the issue of how to make the antenna selection procedure applicable to a large number of antennas becomes an urgent problem that needs to be addressed.

[0009] Disclosure of the essence of the invention

[0010] Embodiments of the present application provide a method for sensing an antenna channel, a device, and a storage medium for performing the sensing of an antenna channel, and are applicable to sensing an antenna channel in a large-scale antenna scenario, so that antenna selection can be performed based on the result of sensing the antenna channel in the large-scale antenna scenario.

[0011] According to the first aspect, an embodiment of the present application provides a method for sounding an antenna channel. In this method, a first communication device transmits a first frame to a second communication device. The first frame includes first indicator information. The first indicator information instructs the second communication device to perform channel sounding of a transmit antenna. The first communication device transmits a first Physical Layer Protocol Data Unit (PPDU) to the second communication device. The first PPDU is used by the second communication device to perform channel sounding of a transmit antenna. The first PPDU includes a first identifier field. The first identifier field indicates the identifier of the first set of transmit antennas.

[0012] The first PPDU may include a data field, or the first PPDU may not include a data field. For example, the first PPDU may be an NDP, which does not include a data field. Since an NDP does not include a data field, overhead can be reduced.

[0013] Furthermore, in the present application, since the NDP includes a first identifier field indicating the identifier of the first set of transmit antennas, the second communication device determines the correspondence between the channel sounding result of the transmit antenna corresponding to the NDP and the identifier of the set of transmit antennas, and the second communication device can determine the identifier of the set of transmit antennas selected based on one or more channel sounding results of the transmit antennas. This makes it possible to prevent the second communication device from incorrectly matching the channel sounding result of the selected transmit antenna with the set of transmit antennas and to perform antenna selection based on the channel sounding results of the antennas in a large-scale antenna scenario.

[0014] In a possible implementation, the first communication device may transmit one or more PPDUs to the second communication device. The first PPDU is one of one or more PPDUs. The second communication device may perform channel sounding of the transmit antenna based on the received one or more PPDUs to obtain a channel sounding result of the transmit antenna. In addition, the second communication device may select a set of transmit antennas based on the received channel sounding result of the transmit antenna and indicate the identifier of the selected set of transmit antennas to the first communication device to perform antenna selection based on the antenna channel sounding result in a large-scale antenna scenario. For example, the first communication device receives a second frame from the second communication device. The second frame includes a feedback result of the first antenna selection. The feedback result of the first antenna selection includes a third identifier field.The third identifier field may be used to carry the identifier of the set of transmit antennas selected by the second communication device. For example, if the set of transmit antennas selected by the second communication device is the first set of transmit antennas, the third identifier field may indicate the identifier of the first set of transmit antennas.

[0015] In a possible implementation, before the first communication device transmits the first frame to the second communication device, the first communication device receives a third frame including third indicator information. The third indicator information is used to request the first communication device to transmit information for performing channel sounding of the transmit antenna. The third indicator information is carried in the high-efficiency option field of the third frame. Since the high-efficiency option field contains a larger number of bits that are used to carry the corresponding antenna selection procedure command, the solution presented in this application can support more PPDUs (for example, can support more than 16 PPDUs) and can support more antenna sets (can support more than 16 antenna sets). Thus, antenna selection can be implemented based on the antenna channel sounding result in a large-scale antenna scenario.

[0016] In a possible implementation, the first communication device and the second communication device can perform negotiation. The second communication device learns, through negotiation, the set of transmit antennas supported by the first communication device; and after the negotiation, the first communication device and the second communication device establish a group identifier for the set of transmit antennas supported by the first communication device. For example, before the first communication device transmits the first frame to the second communication device, the first communication device transmits a fourth frame to the second communication device. The fourth frame includes a fourth identifier field. The fourth identifier field indicates the identifier of at least one set of transmit antennas supported by the first communication device. The identifier of at least one set of transmit antennas includes the identifier of the first set of transmit antennas.

[0017] Furthermore, the first communication device may further indicate to the second communication device a set of transmit antennas corresponding to the identifier of the transmit antenna set supported by the first communication device. In this way, the first communication device can learn the identifier of the transmit antenna set for each set of transmit antennas so that the identifier of the transmit antenna set is carried during transmission. In addition, the second communication device can determine, based on the identifier of the first set of transmit antennas indicated by the first identifier field in the received first PPDU, the antennas specifically included in the identifier of the first set of transmit antennas. Obviously, the second communication device can obtain, through negotiation, more information related to the set of antennas and can subsequently obtain more information related to the communication link, thereby further providing assistance for another subsequent procedure.

[0018] In a possible implementation, before the first communication device transmits the first frame to the second communication device, the first communication device transmits a ninth frame to the second communication device. The ninth frame includes seventh indicator information. The seventh indicator information indicates the total number of sets of transmit antennas supported by the first communication device. Thus, the second communication device can estimate the overhead and duration of the transmit antenna selection procedure based on the seventh indicator information; and the second communication device can further determine, based on the total number of sets of transmit antennas supported by the first communication device, whether to establish an association relationship using the first communication device.

[0019] According to the second aspect, an embodiment of the present application provides a method for sounding an antenna channel. In this method, a second communication device receives a first frame from a first communication device. The first frame includes first indicator information. The first indicator information instructs the second communication device to perform channel sounding of a transmit antenna. The second communication device receives a first physical protocol data unit (PPDU) from the first communication device. The first PPDU is used by the second communication device to perform channel sounding of a transmit antenna. The first PPDU includes a first identifier field. The first identifier field indicates the identifier of the first set of transmit antennas.

[0020] The first PPDU may include a data field, or the first PPDU may not include a data field. For example, the first PPDU may be an NDP. Since an NDP does not include a data field, overhead can be reduced.

[0021] Furthermore, in the present application, since the NDP includes a first identifier field indicating the identifier of the first set of transmit antennas, the second communication device determines the correspondence between the channel sounding result of the transmit antenna corresponding to the NDP and the identifier of the set of transmit antennas, and the second communication device can determine the identifier of the set of transmit antennas selected based on one or more channel sounding results of the transmit antennas. This makes it possible to prevent the second communication device from incorrectly matching the channel sounding result of the selected transmit antenna with the set of transmit antennas and to perform antenna selection based on the channel sounding results of the antennas in a large-scale antenna scenario.

[0022] In a possible implementation, the first communication device may transmit one or more PPDUs to the second communication device. The first PPDU is one of one or more PPDUs. The second communication device may perform channel sounding of the transmit antenna based on the received one or more PPDUs to obtain a channel sounding result of the transmit antenna. In addition, the second communication device may select a set of transmit antennas based on the received channel sounding result of the transmit antenna and indicate the identifier of the selected set of transmit antennas to the first communication device to perform antenna selection based on the antenna channel sounding in a large-scale antenna scenario. For example, the second communication device transmits a second frame to the first communication device. The second frame includes the feedback result of the first antenna selection. The feedback result of the first antenna selection includes a third identifier field.The third identifier field may be used to carry the identifier of the set of transmit antennas selected by the second communication device. For example, if the set of transmit antennas selected by the second communication device is the first set of transmit antennas, the third identifier field may indicate the identifier of the first set of transmit antennas.

[0023] In a possible implementation, before the second communication device receives the first frame, the second communication device transmits a third frame including third indicator information. The third indicator information is used to request the first communication device to transmit information for performing channel sounding of the transmit antenna. The third indicator information is carried in the high-efficiency option field of the third frame. Since the high-efficiency option field contains a larger number of bits that are used to carry the corresponding antenna selection procedure command, the solution presented in this application can support more PPDUs (for example, can support more than 16 PPDUs) and can support more antenna sets (can support more than 16 antenna sets). Thus, antenna selection can be implemented based on the antenna channel sounding result in a large-scale antenna scenario.

[0024] In a possible implementation, the first communication device and the second communication device may perform negotiation. The second communication device learns, through negotiation, the set of transmit antennas supported by the first communication device; and after negotiation, the first communication device and the second communication device establish a group identifier for the set of transmit antennas supported by the first communication device.

[0025] For example, before the second communication device receives the first frame, the second communication device receives a fourth frame from the first communication device. The fourth frame includes a fourth identifier field. The fourth identifier field indicates the identifier of at least one set of transmit antennas supported by the first communication device. The identifier of the at least one set of transmit antennas includes the identifier of the first set of transmit antennas.

[0026] Furthermore, the second communication device can additionally receive from the first communication device a set of transmit antennas corresponding to the identifier of the set of transmit antennas supported by the first communication device. Thus, the first communication device can learn the identifier of the set of transmit antennas for each set of transmit antennas so that the identifier of the set of transmit antennas is carried during transmission. In addition, the second communication device can determine, based on the identifier of the first set of transmit antennas indicated by the first identifier field in the received first PPDU, the antennas specifically included in the identifier of the first set of transmit antennas. Obviously, the second communication device can obtain, through negotiation, more information related to the set of antennas, and can subsequently obtain more information related to the communication link, thereby further providing assistance for another subsequent procedure.

[0027] In a possible implementation, before the second communication device receives the first frame, the second communication device receives a ninth frame from the first communication device. The ninth frame includes seventh indicator information. The seventh indicator information indicates the total number of sets of transmit antennas supported by the first communication device. Thus, the second communication device can estimate the overhead and duration of the transmit antenna selection procedure based on the seventh indicator information; and the second communication device can further determine, based on the total number of sets of transmit antennas supported by the first communication device, whether to establish an association relationship using the first communication device.

[0028] According to any of the first aspect or the second aspect and possible implementations of the first aspect or the second aspect, the present application further provides a possible implementation in which the first identifier field is located in the preamble of the first PPDU. For example, the first identifier field includes some or all bits in the general-purpose signaling field and / or some or all bits in the extremely high-throughput signaling field in the preamble.

[0029] When the first PPDU is an NDP, the existing NDP does not carry the first identifier field, and in the present application, a field in the preamble of the existing NDP may be used to carry the content of the first identifier field, so that the present application can achieve higher compatibility with the legacy technology, and the identifier of the first set of transmit antennas may also be carried in the NDP.

[0030] In addition, in the existing protocol, there are some spare bits in these fields, for example, B20-B24 and B25 of the first symbol, B2 and B8 of the second symbol in the universal signaling field, and B14 and B15 in the signaling field for extremely high throughput, and in the embodiments of the present application, the first identifier field is added to the NDP using the bits in these fields, so that the embodiments of the present application can achieve higher compatibility with the conventional technology.

[0031] Furthermore, in order to maintain compatibility with the existing standard in the case where this application is applicable to a next-generation standard, the first identifier field may include some or all of the bits in the universal signal field and / or some or all of the bits in the next-generation signal field.

[0032] According to any of the first aspect or the second aspect and possible implementations of the first aspect or the second aspect, the present application further provides a possible implementation, in which the PPDU includes a data field and a preamble. The first identifier field may include some or all bits in at least one of the preamble or the data field. For example, the identifier information of the first set of transmit antennas is carried in at least one of a general-purpose signal field, a signal field for extremely high throughput, or an aggregated control subfield of the data field. When the first PPDU includes a data field, in addition to the general-purpose signal field and the signal field for extremely high throughput, the aggregated control subfield of the data field can also be used as the first identifier field.Thus, additional capabilities can be provided for determining the location of the first identifier field. Furthermore, since an existing field can be used to carry the contents of the first identifier field, this application allows for greater compatibility with traditional technology.

[0033] Furthermore, in order to maintain compatibility with the existing standard in the case where this application is applicable to a next-generation standard, the first identifier field may include some or all bits in at least one of: a universal signal field, a next-generation signal field, or an aggregated control subfield of a data field.

[0034] According to any of the first aspect or the second aspect and possible implementations of the first aspect or the second aspect, the present application further provides a possible implementation in which the first frame additionally includes a certain number of NDPs. Thus, the second communication device can determine, based on the first frame, the number of NDPs that need to be subsequently received to check whether an NDP is missing.

[0035] According to any of the first aspect or the second aspect and possible implementations of the first aspect or the second aspect, the present application further provides a possible implementation, in which the first frame further includes a second identifier field. The second identifier field indicates the identifier of the first set of transmit antennas. The second identifier field in the first frame may include identifiers of a plurality of sets of transmit antennas, for example, may include a plurality of sets of transmit antennas corresponding to a plurality of consecutive PPDUs to be subsequently transmitted in the first frame. Thus, the first identifier field in the first PPDU may contain several bits in the bits corresponding to the identifier of the first set of transmit antennas in order to reduce the number of bits occupied by the first identifier field in the first PPDU.The second communication device can determine, on the basis of the first identifier field and the second identifier field, all bits corresponding to the identifier of the first set of transmitting antennas, and the first communication device can be indicated all bits of the set of transmitting antennas selected by the second communication device (for example, the second communication device selects the first set of transmitting antennas), so that the first communication device determines, on the basis of all bits of the set of transmitting antennas transmitted over the feedback channel by the second communication device, the selected set of transmitting antennas by the second communication device.

[0036] According to any of the first aspect or the second aspect and possible implementations of the first aspect or the second aspect, the present application further provides a possible implementation, in which the first indicator information and / or the number of NDPs are carried in at least one station information field, which relates to the first frame and includes the second indicator information. In another possible implementation, the second identifier field includes some or all bits of at least one station information field, which relates to the first frame and which includes the second indicator information. The second indicator information indicates that the station information field includes information related to antenna selection.Thus, when the second indicator information is identified, the second communication device can determine that the station information field carrying the second indicator information carries information related to antenna selection, and then obtain the information related to antenna selection from the station information field. The second indicator information can distinguish the station information field carrying information related to antenna selection from the station information field corresponding to another legacy station, so that in a solution in which the station information field carries information related to antenna selection, the station information field corresponding to the legacy station is not affected, and compatibility with the existing standard is achieved.

[0037] According to any of the first aspect or the second aspect and the possible implementations of the first aspect or the second aspect, the present application further provides a possible implementation in which the second pointer information is carried in the association identifier field in the station information field. For example, a value that is not specified for a specific station in the existing standard can be used as the second pointer information. The second pointer information includes one of the digits: 2008-2043 or 2046. Thus, the second communication device can determine, based on the association identifier field, whether the station information field carries information related to antenna selection or station information corresponding to other second communication information. Obviously, this solution allows for higher compatibility with the conventional technology.

[0038] According to any of the first aspect or the second aspect and the possible implementations of the first aspect or the second aspect, the present application further provides a possible implementation in which the second frame includes a multiple-input / multiple-output control field, and the third identifier field includes some or all of the bits in the multiple-input / multiple-output control field. Thus, the third identifier field can be added to the second frame by using bits in the existing multiple-input / multiple-output control (MIMO Control) field. This solution does not further increase the length of the second frame and enables higher compatibility with conventional technology.

[0039] According to any of the first aspect or the second aspect and the possible implementations of the first aspect or the second aspect, the present application further provides a possible implementation in which the third indicator information is carried in at least one of the following contents in the aggregate control subfield: a control identifier field, an antenna selection command field, or an antenna selection data field. Since the antenna selection command field and the antenna selection data field are obtained by splitting in the existing standard, the antenna selection command field and the antenna selection data field are also obtained by splitting the A-control subfield in the high-performance variant field, so that the present application can achieve higher compatibility with the command form in the existing standard.Additionally, the third indicator information is carried in at least one of the control identifier field, the antenna selection command field, or the antenna selection data field in the A-control subfield. Since conventional technology also includes an antenna selection command field and an antenna selection data field, this solution can be compatible with conventional technology.

[0040] According to any of the first aspect or the second aspect and the possible implementations of the first aspect or the second aspect, the present application further provides a possible implementation in which the number of bits occupied by the antenna selection command field and the antenna selection data field is greater than 7. The number of bits occupied by the antenna selection data field is greater than 4. The number of bits occupied by the antenna selection command field and the antenna selection data field does not exceed 26.

[0041] In an embodiment of the antenna selection procedure based on the high-throughput control (HTC) field in 802.11n, a maximum of four RF chains, eight antennas, and 16 antenna sets are supported. In the embodiments of the present application, since the number of bits in the control information field is large, the MPDU shown in Fig. 6 can contain more types of antenna selection commands, and the antenna selection data field also has more than 4 bits. Therefore, more PPDUs (more than 16 PPDUs can be supported) and more antenna sets (more than 16 antenna sets can be supported) can be supported.

[0042] According to any of the first aspect or the second aspect and possible implementations of the first aspect or the second aspect, the present application further provides a possible implementation, in which the first set of transmit antennas is one of k1 sets of transmit antennas of the first communication device, and k1 is a positive integer. The sets of k1 transmit antennas are in a one-to-one correspondence with the identifiers of the sets of k1 transmit antennas. Since the sets of transmit antennas are in a one-to-one correspondence with the identifiers of the sets of transmit antennas, the second communication device receives two PPDUs at different times that include the same identifier of the antenna set. If the detected channel changes, since the identifiers of the antenna sets included in the two PPDUs are the same, the second communication device determines that the set of antennas does not change and, thus, can determine that the channel itself changes.

[0043] According to any of the first aspect or the second aspect and the possible implementations of the first aspect or the second aspect, the present application further provides a possible implementation in which the first identifier field includes all bits corresponding to the identifier of the first set of transmit antennas. Thus, the second communication device can uniquely determine the identifier of the set of transmit antennas based on the first identifier field contained in the PPDU.

[0044] According to any of the first aspect or the second aspect and the possible implementations of the first aspect or the second aspect, the present application further provides a possible implementation in which the first identifier field includes some bits corresponding to the identifier of the first set of transmit antennas. Thus, it is possible to reduce the number of bits used in the PPDU preamble.

[0045] According to any of the first aspect or the second aspect and the possible implementations of the first aspect or the second aspect, the present application further provides a possible implementation, in which the third frame transmitted by the second communication device to the first communication device may further include a certain number of PPDUs. Accordingly, the first communication device can determine, based on the number of PPDUs carried in the third frame, how many PPDUs should be sent, so that the first communication device determines the number of PPDUs to be subsequently transmitted based on the requirement of the second communication device, and the number of PPDUs to be subsequently transmitted by the first communication device maximally corresponds to the requirement of the second communication device.

[0046] According to any of the first aspect or the second aspect and the possible implementations of the first aspect or the second aspect, the present application further provides a possible implementation in which the first identifier field includes a group identifier of the first set of transmitting antennas and / or a sequence number of the first PPDU. This allows for increased flexibility of the solution.

[0047] According to a third aspect, an embodiment of the present application provides a method for sounding an antenna channel. In this method, a first communication device transmits an eleventh frame to a second communication device. The eleventh frame includes first indicator information. The first indicator information instructs the second communication device to perform channel sounding of the transmit antenna. The first communication device transmits a third physical protocol data unit (PPDU) to the second communication device. The third PPDU is used by the second communication device to perform channel sounding of the transmit antenna. The third PPDU includes M1 first information fields corresponding to M1 sets of transmit antennas. M1 is an integer greater than 1. The first information field is used to perform channel sounding of the transmit antenna.The first information field includes at least one of a short EHT training field, a long EHT training field, and a packet extension field. The first communication device can aggregate PPDUs corresponding to the sets of M1 transmit antennas to be transmitted into a single PPDU to reduce overhead, improve antenna selection efficiency, and increase system throughput.

[0048] According to a fourth aspect, an embodiment of the present application provides a method for sounding an antenna channel. In this method, a second communication device receives an eleventh frame from a first communication device. The eleventh frame includes first indicator information. The first indicator information instructs the second communication device to perform channel sounding of the transmit antenna. The second communication device receives a third PPDU from the first communication device. The third PPDU is used by the second communication device to perform channel sounding of the transmit antenna. The third PPDU includes M1 first information fields corresponding to M1 sets of transmit antennas. M1 is an integer greater than 1. The first information field is used to perform channel sounding of the transmit antenna. The first information field includes at least one of a short training field EHT, a long training field EHT, and a packet extension field.The first communication device may aggregate PPDUs corresponding to sets of M1 transmit antennas to be transmitted into one PPDU to reduce the amount of overhead, improve the antenna selection efficiency, and increase the system throughput.

[0049] According to any of the third aspect or the fourth aspect and possible implementations of the third aspect or the fourth aspect, the present application further provides a possible implementation in which the third PPDU includes a preamble. The preamble includes at least one of the following fields: a legacy short training field, a legacy long training field, a legacy signal field, a repeated legacy signal field, a universal signal field, or a signal field for extremely high throughput. Thus, the portion shared by all sets of transmit antennas can be sent only once to reduce the amount of overhead.

[0050] According to any of the third aspect or the fourth aspect and the possible implementations of the third aspect or the fourth aspect, the present application further provides a possible implementation in which the duration of the packet extension fields in any two of the M1 first information fields is the same. Thus, the compatibility of the reception procedure can be improved.

[0051] According to any of the third aspect or the fourth aspect and possible implementations of the third aspect or the fourth aspect, the present application further provides a possible implementation in which the duration of the packet extension fields in at least two of the M1 first information fields is different. For example, a packet extension field different from the extension field of the last packet may be shorter than the extension field of the last packet and sufficient for the first communication device to switch the antenna. Thus, the efficiency of signal transmission can be improved.

[0052] According to a fifth aspect, an embodiment of the present application provides a method for sounding an antenna channel. In this method, a first communication device transmits a fifth frame to a second communication device. The fifth frame includes fourth indicator information. The fourth indicator information indicates the need to perform channel sounding of a receive antenna in the first communication device. The first communication device receives a second PPDU from the second communication device. The second PPDU is used by the first communication device to perform channel sounding of a receive antenna. The second PPDU includes a fifth identifier field. The fifth identifier field indicates the identifier of the first set of receive antennas.

[0053] The second PPDU may include a data field, or the second PPDU may not include a data field. For example, the second PPDU may be an NDP. Since an NDP does not include a data field, overhead can be reduced.

[0054] Furthermore, the first communication device can perform receive antenna channel sounding on the first set of receive antennas based on the second PPDU to obtain a receive antenna channel sounding result corresponding to the first set of receive antennas. Since the NDP includes a fifth identifier field indicating the identifier of the first set of receive antennas, the first communication device determines the correspondence between the receive antenna channel sounding result corresponding to the NDP and the identifier of the set of receive antennas, and the first communication device can determine the identifier of the set of receive antennas selected based on one or more receive antenna channel sounding results. This makes it possible to prevent the first communication device from incorrectly matching the selected receive antenna channel sounding result with the set of receive antennas and to perform antenna selection based on the antenna channel sounding results in a large-scale antenna scenario.

[0055] In a possible implementation, the second communication device may transmit one or more PPDUs to the first communication device. The second PPDU is one of the one or more PPDUs. The first communication device may perform channel sounding of the receive antenna based on the received one or more PPDUs to obtain a channel sounding result of the receive antenna. In addition, the first communication device may select a set of receive antennas based on the received channel sounding result of the receive antenna and indicate the identifier of the selected set of receive antennas to the second communication device to perform antenna selection based on the antenna channel sounding in a large-scale antenna scenario. For example, the first communication device transmits the sixth frame to the second communication device. The sixth frame includes the second antenna selection feedback result. The second antenna selection feedback result includes a seventh identifier field.The seventh identifier field may be used to carry the identifier of the set of receive antennas selected by the first communication device. For example, if the set of receive antennas selected by the first communication device is the first set of receive antennas, the seventh identifier field may indicate the identifier of the first set of receive antennas.

[0056] In a possible implementation, before the first communication device transmits the fifth frame to the second communication device, the method further includes the following: the first communication device receives a seventh frame including sixth indicator information. The sixth indicator information is used to request the first communication device to transmit information for performing channel sounding of the receiving antenna. The sixth indicator information is carried in the high-efficiency option field of the seventh frame. Since the high-efficiency option field contains a larger number of bits that are used to carry the corresponding antenna selection procedure command, the solution presented in this application can support more PPDUs (for example, can support more than 16 PPDUs) and can support more antenna sets (can support more than 16 antenna sets).Thus, the antenna selection can be realized based on the antenna channel sounding result in a large-scale antenna scenario.

[0057] In a possible implementation, the first communication device and the second communication device may perform negotiation. The second communication device learns, through negotiation, the set of receiving antennas supported by the first communication device; and after negotiation, the first communication device and the second communication device establish a group identifier for the set of receiving antennas supported by the first communication device.

[0058] For example, in a possible implementation, before the first communication device transmits the fifth frame to the second communication device, the method further includes the following: the first communication device transmits an eighth frame to the second communication device. The eighth frame includes an eighth identifier field. The eighth identifier field indicates the identifier of at least one set of receive antennas supported by the first communication device. The identifier of the at least one set of receive antennas includes the identifier of the first set of receive antennas.

[0059] Furthermore, the first communication device may further indicate to the second communication device a set of receive antennas corresponding to the identifier of the set of receive antennas supported by the first communication device. Thus, the second communication device can carry the identifier of the set of receive antennas when sending a PPDU. In addition, the second communication device can determine the antennas specifically included in the first set of receive antennas. Obviously, the second communication device can obtain, through negotiation, more information related to the set of antennas and can subsequently obtain more information related to the communication link, thereby further providing assistance for other subsequent procedures.

[0060] For example, in a possible implementation, before the first communication device transmits the fifth frame to the second communication device, the method further includes the following: the first communication device transmits the tenth frame to the second communication device. The tenth frame includes eighth indicator information. The eighth indicator information indicates the total number of sets of receiving antennas supported by the first communication device. Thus, the second communication device can estimate the overhead and the duration of the receiving antenna selection procedure based on the eighth indicator information; and the second communication device can further determine, based on the total number of sets of receiving antennas supported by the first communication device, whether to establish an association relationship using the first communication device.

[0061] According to a sixth aspect, an embodiment of the present application provides a method for sounding an antenna channel. In this method, a second communication device receives a fifth frame from a first communication device. The fifth frame includes fourth indicator information. The fourth indicator information indicates the need to perform channel sounding of the receive antenna in the first communication device. The second communication device transmits a second PPDU to the first communication device. The second PPDU is used by the first communication device to perform channel sounding of the receive antenna. The second PPDU includes a fifth identifier field. The fifth identifier field indicates the identifier of the first set of receive antennas.

[0062] The second PPDU may include a data field, or the second PPDU may not include a data field. For example, the second PPDU may be an NDP. Since an NDP does not include a data field, overhead can be reduced.

[0063] Furthermore, in the present application, since the NDP includes a fifth identifier field indicating the identifier of the first set of receive antennas, the first communication device determines the correspondence between the channel sounding result of the receive antenna corresponding to the NDP and the identifier of the set of receive antennas, and the first communication device can determine the identifier of the set of receive antennas selected based on one or more channel sounding results of the receive antennas. This makes it possible to prevent the first communication device from incorrectly matching the selected channel sounding result of the receive antenna with the set of receive antennas and to perform antenna selection based on the channel sounding results of the antennas in a large-scale antenna scenario.

[0064] In a possible implementation, the second communication device may transmit one or more PPDUs to the first communication device. The second PPDU is one of the one or more PPDUs. The first communication device may perform channel sounding of the receive antenna based on the received one or more PPDUs to obtain a channel sounding result of the receive antenna. In addition, the first communication device may select a set of receive antennas based on the received channel sounding result of the receive antenna and indicate the identifier of the selected set of receive antennas to the second communication device to perform antenna selection based on the antenna channel sounding in a large-scale antenna scenario. For example, the second communication device receives the sixth frame from the first communication device. The sixth frame includes the second antenna selection feedback result. The second antenna selection feedback result includes a seventh identifier field.The seventh identifier field may be used to carry the identifier of the set of receive antennas selected by the first communication device. For example, if the set of receive antennas selected by the first communication device is the first set of receive antennas, the seventh identifier field may indicate the identifier of the first set of receive antennas.

[0065] In a possible implementation, before the second communication device receives the fifth frame from the first communication device, the method further includes the following: the second communication device transmits a seventh frame including sixth indicator information. The sixth indicator information is used to request the first communication device to transmit information for performing channel sounding of the receiving antenna. The sixth indicator information is carried in the high-efficiency option field of the seventh frame. Since the high-efficiency option field contains a larger number of bits that are used to carry the corresponding antenna selection procedure command, the solution presented in this application can support more PPDUs (for example, can support more than 16 PPDUs) and can support more antenna sets (can support more than 16 antenna sets).Thus, the antenna selection can be realized based on the antenna channel sounding result in a large-scale antenna scenario.

[0066] In a possible implementation, the first communication device and the second communication device may perform negotiation. The second communication device learns, through negotiation, the set of receiving antennas supported by the first communication device; and after negotiation, the first communication device and the second communication device establish a group identifier for the set of receiving antennas supported by the first communication device.

[0067] For example, in a possible implementation, before the second communication device receives the fifth frame from the first communication device, the second communication device receives the eighth frame from the first communication device. The eighth frame includes an eighth identifier field. The eighth identifier field indicates the identifier of at least one set of receive antennas supported by the first communication device. The identifier of the at least one set of receive antennas includes the identifier of the first set of receive antennas.

[0068] Furthermore, the first communication device may further indicate to the second communication device a set of receive antennas corresponding to the identifier of the set of receive antennas supported by the first communication device. Thus, the second communication device can carry the identifier of the set of receive antennas when sending the PPDU. In addition, the second communication device can determine the antennas specifically included in the first set of receive antennas. Obviously, the second communication device can obtain, through negotiation, more information related to the set of antennas and can subsequently obtain more information related to the communication link, thereby further providing assistance for other subsequent procedures.

[0069] In a possible implementation, before the first communication device transmits the fifth frame to the second communication device, the second communication device receives the tenth frame from the first communication device. The tenth frame includes eighth indicator information. The eighth indicator information indicates the total number of sets of receive antennas supported by the first communication device. Thus, the second communication device can estimate the overhead and duration of the receive antenna selection procedure based on the eighth indicator information; and the second communication device can further determine, based on the total number of sets of receive antennas supported by the first communication device, whether to establish an association relationship using the first communication device.

[0070] According to any of the fifth aspect or the sixth aspect and possible implementations of the fifth aspect or the sixth aspect, the present application further provides a possible implementation in which the fifth identifier field is located in the preamble of the second PPDU. For example, the fifth identifier field represents some or all of the bits in the general-purpose signaling field and / or some or all of the bits in the extremely high-bandwidth signaling field in the preamble. When the second PPDU is an NDP, the existing NDP does not carry the fifth identifier field, and in the present application, a field in the preamble of the existing NDP can be used to carry the content of the fifth identifier field, so that the present application can achieve higher compatibility with the legacy technology, and the identifier of the first set of receiving antennas can also be carried in the NDP.

[0071] Furthermore, in the existing protocol, there are a number of spare bits in these fields, for example, B20-B24 and B25 of the first symbol and B2 and B8 of the second symbol in the universal signaling field, and B14 and B15 in the signaling field for extremely high throughput, and in the embodiments of the present application, the first identifier field is added to the NDP using the bits in these fields, so that the embodiments of the present application can achieve higher compatibility with the conventional technology.

[0072] Furthermore, in order to maintain compatibility with the existing standard in the case where this application is applicable to the next generation standard, the fifth identifier field may include some or all of the bits in the universal signal field and / or some or all of the bits in the next generation signal field.

[0073] According to any of the fifth aspect or the sixth aspect and possible implementations of the fifth aspect or the sixth aspect, the present application further provides a possible implementation, in which the PPDU includes a data field and a preamble. The fifth identifier field includes some or all bits in at least one of the preamble or the data field. For example, the identifier information of the first set of receiving antennas is carried in at least one of a general-purpose signal field, a signal field for extremely high throughput, or an aggregated control subfield of the data field. When the second PPDU includes a data field, in addition to the general-purpose signal field and the signal field for extremely high throughput, the aggregated control subfield of the data field can also be used as the fifth identifier field.Thus, more flexibility can be provided for specifying the location of the fifth identifier field. Furthermore, since an existing field can be used to carry the contents of the fifth identifier field, this application allows for greater compatibility with conventional technology.

[0074] Furthermore, in order to maintain compatibility with the existing standard in the case where this application is applicable to the next generation standard, the identifier information of the first set of receiving antennas is carried in at least one of: a universal signal field, a next generation signal field, or an aggregated control subfield of a data field.

[0075] According to any of the fifth aspect or the sixth aspect and possible implementations of the fifth aspect or the sixth aspect, the present application further provides a possible implementation in which the fifth frame additionally includes a certain number of NDPs. Thus, the second communication device can determine, based on the first frame, the number of NDPs that need to be subsequently received to check whether an NDP is missed.

[0076] According to any of the fifth aspect or the sixth aspect and possible implementations of the fifth aspect or the sixth aspect, the present application further provides a possible implementation, in which the fifth frame further includes a sixth identifier field. The sixth identifier field indicates the identifier of the first set of receive antennas. The sixth identifier field in the fifth frame may include identifiers of a plurality of sets of receive antennas, for example, may include a plurality of sets of receive antennas corresponding to a plurality of consecutive PPDUs to be subsequently transmitted in the fifth frame. Thus, the fifth identifier field in the second PPDU may contain several bits in the bits corresponding to the identifier of the first set of receive antennas in order to reduce the number of bits occupied by the fifth identifier field in the second PPDU.The first communication device can determine, based on the fifth identifier field and the sixth identifier field, all bits corresponding to the identifier of the first set of receiving antennas, and the first communication device can be indicated all bits of the set of transmitting antennas selected by the second communication device (for example, the second communication device selects the first set of transmitting antennas), so that the first communication device determines, based on all bits of the set of transmitting antennas transmitted over the feedback channel by the second communication device, the selected set of transmitting antennas by the second communication device.

[0077] According to any of the fifth aspect or the sixth aspect and possible implementations of the fifth aspect or the sixth aspect, the present application further provides a possible implementation, in which the fourth indicator information and / or the number of NDPs are carried in at least one station information field, which relates to the fifth frame and includes the fifth indicator information. In another possible implementation, the sixth identifier field includes some or all bits of at least one station information field, which relates to the fifth frame and which includes the fifth indicator information. The fifth indicator information indicates that the station information field includes information related to antenna selection.Thus, when the fifth indicator information is identified, the second communication device can determine that the station information field carrying the fifth indicator information carries information related to antenna selection, and then obtain the information related to antenna selection from the station information field. The fifth indicator information can distinguish the station information field carrying information related to antenna selection from the station information field corresponding to another legacy station. Thus, in a solution in which the station information field carries information related to antenna selection, the station information field corresponding to the legacy station is not affected, and compatibility with the existing standard is achieved.

[0078] According to any of the fifth aspect or the sixth aspect and possible implementations of the fifth aspect or the sixth aspect, the present application further provides a possible implementation in which the fifth pointer information is carried in the association identifier field of the station information field. For example, a value that is not specified for a specific station in the existing standard can be used as the fifth pointer information. The fifth pointer information includes one of the numbers from 2008 to 2043 or 2046. Thus, the second communication device can determine, based on the association identifier field, whether the station information field carries information related to antenna selection or station information corresponding to another second communication device. Obviously, this solution allows for higher compatibility with the conventional technology.

[0079] According to any of the fifth aspect or the sixth aspect and possible implementations of the fifth aspect or the sixth aspect, the present application further provides a possible implementation, in which the fourth indicator information is carried in the trigger type field of the fifth frame; and / or the number of NDPs and / or the sixth identifier field are carried in some or all bits of at least one of the following contents: a reserved bit of the general information field, a reserved bit of the user information list field, trigger-dependent general information, or trigger-dependent user information. Alternatively, the fifth frame can be the second trigger frame. In this solution, a bit in the existing second trigger frame can be used to add information related to the antenna selection to the second trigger frame. Thus, this solution can be compatible with the conventional technology.

[0080] According to any of the fifth aspect or the sixth aspect and possible implementations of the fifth aspect or the sixth aspect, the present application further provides a possible implementation in which the sixth frame includes a MIMO control field and the seventh identifier field includes some or all of the bits of the MIMO control field. Thus, the third identifier field can be added to the second frame using bits in the existing MIMO Control field. This solution does not further increase the length of the second frame and enables higher compatibility with conventional technology.

[0081] According to any of the fifth aspect or the sixth aspect and possible implementations of the fifth aspect or the sixth aspect, the present application further provides a possible implementation in which the sixth indicator information is carried in at least one of the following contents in the A-control subfield: a control identifier field, an antenna selection command field, or an antenna selection data field. Since the antenna selection command field and the antenna selection data field are obtained by splitting in the existing standard, the antenna selection command field and the antenna selection data field are also obtained by splitting the A-control subfield in the high-performance variant field, so that the present application can ensure higher compatibility with the command form in the existing standard. In addition, the sixth indicator information is further carried in at least one of the control identifier field, the antenna selection command field, or the antenna selection data field in the A-control subfield.This application allows for compatibility with traditional technologies.

[0082] According to any of the fifth aspect or the sixth aspect and the possible implementations of the fifth aspect or the sixth aspect, the present application further provides a possible implementation in which the number of bits occupied by the antenna selection command field and the antenna selection data field is greater than 7. The number of bits occupied by the antenna selection data field is greater than 4. The number of bits occupied by the antenna selection command field and the antenna selection data field does not exceed 26.

[0083] In an embodiment of the antenna selection procedure based on the High Throughput Control (HTC) field in 802.11n, a maximum of four RF chains, eight antennas, and 16 antenna sets are supported. In the embodiments of the present application, since the number of bits in the control information field is large, the MPDU shown in Fig. 6 can contain more types of antenna selection commands, and the antenna selection data field also has more than 4 bits. Therefore, more PPDUs (more than 16 PPDUs can be supported) and more antenna sets (more than 16 antenna sets can be supported) can be supported.

[0084] According to any of the fifth aspect or the sixth aspect and possible implementations of the fifth aspect or the sixth aspect, the present application further provides a possible implementation, in which the first set of receive antennas is one of k2 sets of receive antennas of the first communication device, and k2 is a positive integer. The sets of k2 receive antennas are in a one-to-one correspondence with the identifiers of the sets of k2 receive antennas. Since the sets of receive antennas are in a one-to-one correspondence with the identifiers of the sets of receive antennas, the second communication device receives two PPDUs at different times that include the same identifier of the antenna set. If the detected channel changes, since the identifiers of the antenna sets included in the two PPDUs are the same, the second communication device determines that the set of antennas does not change and, thus, can determine that the channel itself changes.

[0085] According to any of the fifth aspect or the sixth aspect and possible implementations of the fifth aspect or the sixth aspect, the present application further provides a possible implementation in which the fifth identifier field includes all bits corresponding to the identifier of the first set of receiving antennas. Thus, the second communication device can uniquely determine the identifier of the set of receiving antennas based on the first identifier field contained in the PPDU.

[0086] According to any of the fifth aspect or the sixth aspect and possible implementations of the fifth aspect or the sixth aspect, the present application further provides a possible implementation in which the fifth identifier field includes some bits corresponding to the identifier of the first set of receive antennas. Thus, it is possible to reduce the number of bits used in the PPDU preamble.

[0087] According to any of the fifth aspect or the sixth aspect and the possible implementations of the fifth aspect or the sixth aspect, the present application further provides a possible implementation, in which the seventh frame transmitted by the second communication device to the first communication device further includes a certain number of PPDUs. Thus, the first communication device can determine, based on the number of PPDUs carried in the seventh frame, the number of PPDUs that are necessary for further transmission by the second communication device, so that the number of PPDUs that need to be subsequently transmitted by the second communication device and which are determined by the first communication device maximally meets the requirements of the second communication device.

[0088] According to any of the fifth aspect or the sixth aspect and the possible implementations of the fifth aspect or the sixth aspect, the present application further provides a possible implementation in which the fifth identifier field includes a group identifier of the first set of receiving antennas and / or a sequence number of the second PPDU. This allows for increased flexibility of the solution.

[0089] According to the seventh aspect, an embodiment of the present application provides a method for sounding an antenna channel. In this method, a first communication device transmits a twelfth frame to a second communication device. The twelfth frame includes fourth indicator information. The fourth indicator information indicates the need to perform channel sounding of the receive antenna in the first communication device. The first communication device receives a fourth PPDU from the second communication device. The fourth PPDU is used by the second communication device to perform channel sounding of the receive antenna. The fourth PPDU includes M2 second information fields corresponding to M2 sets of receive antennas. M2 is an integer greater than 1. The second information field is used to perform channel sounding of the receive antenna. The second information field includes at least one of a short training field EHT, a long training field EHT, and a packet extension field.

[0090] The second communication device can aggregate PPDUs corresponding to M2 sets of receiving antennas that need to be transmitted into one PPDU to reduce the amount of overhead, improve the efficiency of antenna selection, and increase the system throughput.

[0091] According to an eighth aspect, an embodiment of the present application provides a method for sounding an antenna channel. In this method, a second communication device receives a twelfth frame from a first communication device. The twelfth frame includes fourth indicator information. The fourth indicator information indicates the need to perform channel sounding of the receive antenna in the first communication device. The second communication device transmits a fourth PPDU to the first communication device. The fourth PPDU is used by the second communication device to perform channel sounding of the receive antenna. The fourth PPDU includes M2 second information fields corresponding to M2 sets of receive antennas. M2 is an integer greater than 1. The second information field is used to perform channel sounding of the receive antenna. The second information field includes at least one of a short training field EHT, a long training field EHT, and a packet extension field.

[0092] The second communication device can aggregate PPDUs corresponding to M2 sets of receiving antennas that need to be transmitted into one PPDU to reduce the amount of overhead, improve the efficiency of antenna selection, and increase the system throughput.

[0093] According to any of the seventh aspect or the eighth aspect and possible implementations of the seventh aspect or the eighth aspect, the present application further provides a possible implementation, in which the fourth PPDU includes a preamble. The preamble includes at least one of the following fields: a legacy short training field (L-STF), a legacy long training field (L-LTF), a legacy signaling field (L-SIG), a repeated legacy signaling field (RL-SIG), a universal signaling field (U-SIG), or a signaling field (EHT-SIG) for extremely high throughput. In this way, the part shared by all sets of transmit antennas can be sent only once in order to reduce the amount of overhead.

[0094] According to any of the seventh aspect or the eighth aspect and the possible implementations of the seventh aspect or the eighth aspect, the present application further provides a possible implementation in which the duration of the packet extension fields in any two of the M2 second information fields is the same. Thus, the compatibility of the reception procedure can be improved.

[0095] According to any of the seventh aspect or the eighth aspect and possible implementations of the seventh aspect or the eighth aspect, the present application further provides a possible implementation in which the duration of the packet extension fields in at least two of the M2 second information fields is different. For example, a packet extension field different from the extension field of the last packet may be shorter than the extension field of the last packet and sufficient for the first communication device to switch the antenna. Thus, the efficiency of signal transmission can be improved.

[0096] According to the ninth aspect, a communication device is provided, which includes a communication unit and a processing unit. The communication device may be the aforementioned first communication device or may be the aforementioned second communication device. The communication device can implement any aspect of the first to eighth aspects and any implementations of the first aspect to the eighth aspect. The communication unit is configured to perform functions related to sending and receiving. If necessary, the communication unit includes a receiving unit and a sending unit. In an embodiment, the communication device is a communication chip, the processing unit may be a processing circuit, one or more processors or processor cores, and the communication unit may be an interface circuit, an input / output circuit, or a port of the communication chip.

[0097] In another embodiment, the communication unit may be a transmitter and a receiver, or the communication unit may be a transmitting machine and a receiving machine.

[0098] If necessary, the communication device further includes modules that can be configured to perform any of the first to eighth aspects and any implementations of the first to eighth aspects.

[0099] According to the tenth aspect, a communication device is provided, including a processor and a transceiver. The communication device may be the aforementioned first communication device or may be the aforementioned second communication device. If necessary, the communication device further includes a memory. The memory is for storing a computer program or instructions. The processor is configured to retrieve the computer program or instructions from the memory and execute the computer program or instructions. When the processor executes the computer program or instructions in the memory, the communication device is capable of performing any of the first to eighth aspects and any implementations of the first to eighth aspects.

[0100] One or more processors and one or more memory devices can be used as needed.

[0101] If necessary, the memory can be integrated with the processor, or the memory and processor can be located separately.

[0102] If necessary, the transceiver may include a transmitting machine (transmitter) and a receiving machine (receiver).

[0103] According to the eleventh aspect, a communication device is provided, including a processor. The communication device may be the aforementioned first communication device or may be the aforementioned second communication device. The processor is connected to a memory and can be configured to perform any of the first to eighth aspects and any implementations of the first to eighth aspects. The communication device may be the aforementioned first communication device or may be the aforementioned second communication device. If necessary, the communication device further includes a memory. If necessary, the communication device further includes a communication interface, and the processor is connected to the communication interface.

[0104] In one implementation, when the communication device is the first communication device, the communication interface may be a transceiver or an I / O interface. The transceiver may optionally be a transceiver circuit. The I / O interface may optionally be an I / O circuit.

[0105] In another embodiment, when the communication device is a microcircuit or a microcircuit system of the first communication device, the communication interface may be an input / output interface, an interface circuit, an output circuit, an input circuit, a contact, a circuit related to this device, etc., which are implemented on the microcircuit or in the microcircuit system. Alternatively, the processor may be implemented as a processing circuit or a logic circuit.

[0106] In one implementation, when the communication device is a second communication device, the communication interface may be a transceiver or an input / output interface. The transceiver may optionally be a transceiver circuit. The input / output interface may optionally be an input / output circuit.

[0107] In another embodiment, when the communication device is a microcircuit or a microcircuit system of a second communication device, the communication interface may be an input / output interface, an interface circuit, an output circuit, an input circuit, a contact, a circuit related to this device, etc., which are implemented on the microcircuit or in the microcircuit system. Alternatively, the processor may be implemented as a processing circuit or a logic circuit.

[0108] According to the twelfth aspect, a system is provided, and the system includes the above-mentioned first communication device and the above-mentioned second communication device.

[0109] According to the thirteenth aspect, a computer program product is provided, and this computer program product includes a computer program (which may also be referred to as code or instructions). When the computer program is executed, the computer has the ability to execute any of the first through eighth aspects and any implementations of the first through eighth aspects.

[0110] According to the fourteenth aspect, a computer-readable storage medium is provided, and the computer-readable storage medium stores a computer program (which may also be referred to as code or instructions). When the computer program is executed on a computer, the computer has the ability to execute any of the first to eighth aspects and any implementations of the first to eighth aspects.

[0111] According to the fifteenth aspect, a chip system is provided. The chip system may include a processing circuit. The processing circuit may be configured to perform any of the first to eighth aspects and any implementations of the first to eighth aspects using an interface circuit. If necessary, the chip system further includes a memory. The memory is intended for storing a computer program (which may also be referred to as code or instructions). The processing circuit may be configured to recall the computer program from the memory and execute the computer program, so that a device on which the chip system is installed executes any of the first to eighth aspects and any implementations of the first to eighth aspects.

[0112] According to the sixteenth aspect, a processing device is provided that includes an interface circuit and a processing circuit. The interface circuit may include an input circuit and an output circuit. The processing circuit is configured to: receive a signal using the input circuit and transmit a signal using the output circuit. Therefore, any of the first to eighth aspects and any implementations of the first to eighth aspects can be implemented.

[0113] In a specific implementation process, the above-mentioned processing device may be a microcircuit, the input circuit may be an input terminal, the output circuit may be an output terminal, and the processing circuit may be a transistor, a gate circuit, a flip-flop circuit, any logic circuit, etc. The input signal received by the input circuit may be received and input, for example, but not limited to, into a receiver, the signal output by the output circuit may be output, for example, but not limited to, into a transmitter and transmitted by the transmitter, and the input circuit and the output circuit may be the same circuit, where the circuit is used as an input circuit and an output circuit at different times. In the present application, specific implementations of the processor and various circuits are not limited.

[0114] In another implementation, the communication device may be some components of the first communication device, for example, an integrated circuit product such as a microcircuit system or a communication chip. The interface circuit may be an input / output interface, an interface circuit, an output circuit, an input circuit, a contact, a corresponding circuit, etc., which are implemented on a microcircuit or microcircuit system. The processing circuit may be a logic circuit on the microcircuit.

[0115] In another implementation, the communication device may be some components of a second communication device, for example, an integrated circuit product such as a microcircuit system or a communication microcircuit. The interface circuit may be an input / output interface, an interface circuit, an output circuit, an input circuit, a contact, a corresponding circuit, etc., which are implemented on the microcircuit or microcircuit system. The processing circuit may be a logic circuit implemented on the microcircuit.

[0116] Brief description of drawings

[0117] Fig. 1 is a schematic representation of the architecture of a system to which an embodiment of the present application is applicable;

[0118] Fig. 2 is a schematic representation of another system architecture according to an embodiment of the present application;

[0119] Fig. 3 is a schematic representation of the structure of a communication device according to an embodiment of the present application;

[0120] Fig. 4 is a schematic representation of the signal interaction of the method for probing an antenna channel according to an embodiment of the present application;

[0121] Fig. 5 is a schematic representation of the signal interaction of another method for probing an antenna channel according to an embodiment of the present application;

[0122] Fig. 6 is a schematic diagram of the structure of an MPDU that can carry a third frame, according to an embodiment of the present application;

[0123] Fig. 7 is a schematic diagram of the structure of a first frame when the first frame is an NDPA frame, according to an embodiment of the present application;

[0124] Fig. 8a is a schematic diagram of the structure of a first PPDU when the first PPDU is an NDP, according to an embodiment of the present application;

[0125] Fig. 8b is a schematic diagram of the structure of a first PPDU when the first PPDU is a sounding NDP NG, according to an embodiment of the present application;

[0126] Fig. 8c is a schematic diagram of the structure of a first PPDU including a data field according to an embodiment of the present application;

[0127] Fig. 9 is a schematic diagram of a structure of a MIMO control field in a second frame when the second frame is a beamforming report frame, according to an embodiment of the present application;

[0128] Fig. 10 is a schematic representation of the signal interaction of another method for probing an antenna channel according to an embodiment of the present application;

[0129] Fig. 11 is a schematic representation of a frame structure of a third PPDU according to an embodiment of the present application;

[0130] Fig. 12 – schematic representation of the basic diagram of the signal interaction of the method for probing an antenna channel according to an embodiment of the present application;

[0131] Fig. 13 is a schematic representation of the signal interaction of another method for probing an antenna channel according to an embodiment of the present application;

[0132] Fig.14A and Fig.14B are schematic diagrams of the structure of the second trigger frame according to an embodiment of the present application;

[0133] Fig. 15 is a schematic diagram of the structure of a fifth frame when the fifth frame is an NDPA frame, according to an embodiment of the present application;

[0134] Fig. 16a is a schematic diagram of the structure of a second PPDU when the second PPDU is an NDP, according to an embodiment of the present application;

[0135] Fig. 16b is a schematic diagram of the structure of a second PPDU when the second PPDU is an NDP, according to an embodiment of the present application;

[0136] Fig. 16c is a schematic diagram of the structure of a second PPDU including a data field, according to an embodiment of the present application;

[0137] Fig. 17 is a schematic representation of the signal interaction of another method for probing an antenna channel according to an embodiment of the present application;

[0138] Fig. 18 is a schematic representation of a frame structure of a fourth PPDU according to an embodiment of the present application;

[0139] Fig. 19 is a schematic diagram of a frame structure of another fourth PPDU according to an embodiment of the present application;

[0140] Fig. 20 is a schematic representation of the architecture of another communication device according to an embodiment of the present application;

[0141] Fig. 21 is a schematic representation of the architecture of another communication device according to an embodiment of the present application; and

[0142] Fig. 22 is a schematic representation of the architecture of another communication device according to an embodiment of the present application.

[0143] Implementation of the invention

[0144] The technical solutions of this application are described below with reference to the accompanying drawings.

[0145] Figure 1 shows a schematic diagram of an example of the architecture of a communication system to which an embodiment of the present application is applicable. As shown in Figure 1, the communication system includes a first communication device 101 and a second communication device 102. This embodiment of the present application provides an antenna selection solution that can be used to perform antenna selection for a device. In this embodiment of the present application, an example is used for description in which the antenna selection is performed in the first communication device 101. If the antenna selection needs to be performed in the second communication device 102, the antenna selection procedure of the second communication device 102 should refer to the antenna selection procedure of the first communication device 101. The details are not described again here.

[0146] The first communication device 101 may include a transmitting antenna and a receiving antenna. This embodiment of the present application provides a solution for selecting a transmitting antenna for the first communication device 101. In this solution, the first communication device 101 transmits a first frame to the second communication device 102. The first frame includes first indicator information. The first indicator information indicates the second communication device to perform channel sounding of the transmitting antenna. The first communication device 101 transmits a first physical layer protocol data unit (PPDU) to the second communication device 102. The first PPDU includes a first identifier field. The first identifier field indicates the identifier of the first set of transmitting antennas.

[0147] In a possible implementation, the first PPDU may be a PPDU that includes a data field.

[0148] In another possible implementation, the first PPDU may not include a data field. For example, the first PPDU is a null data packet (NDP). In this embodiment of the present application, the NDP may also be referred to as a null data packet. The NDP may not include a data field.

[0149] When the first PPDU is an NDP, since the NDP does not include a data field, the overhead can be reduced. In particular, in a large-scale antenna scenario, since there are a large number of antenna sets, there are also a large number of PPDUs for transmit antenna channel sounding, and accordingly, the overhead for transmit antenna selection increases. However, in this embodiment of the present application, the overhead in a large-scale antenna scenario can be further reduced by this solution, in which transmit antenna channel sounding is performed based on the NDP.

[0150] In addition, in the current possible implementation, since the NDP does not include a data field, the NDP cannot carry PPDU sequence number information. The second communication device can only derive the PPDU sequence number information corresponding to the NDP based on the sequence of NDPs received by the second communication device. However, once the second communication device misses the NDP, the second communication device cannot correctly derive the PPDU sequence number information corresponding to the received NDP, and cannot correctly feedback the correspondence between the channel sounding result of the transmit antenna and the PPDU sequence number information to the first communication device. Therefore, a transmit antenna selection error may occur in the first communication device.However, in a large-scale antenna scenario, since there are more sets of antennas, there is a higher probability of error when the second communication device determines the sequence number information of the PPDU corresponding to the NDP.

[0151] To solve the above-mentioned problem, in this embodiment of the present application, a first identifier field indicating the identifier of the first set of transmit antennas is added to the NDP, so that the second communication device determines the identifier of the first set of transmit antennas corresponding to the received NDP, and the second communication device can determine the channel sounding result of the transmit antenna obtained based on the NDP as the channel sounding result of the transmit antenna corresponding to the identifier of the first set of transmit antennas. Since the second communication device can determine the correspondence between the channel sounding result of the transmit antenna corresponding to the NDP and the identifier of the set of transmit antennas, and the second communication device can determine the identifier of the set of transmit antennas selected based on one or more antenna channel sounding results.This prevents the second communication device from incorrectly matching the sounding result of the selected transmit antenna channel with the transmit antenna set, and enables antenna selection based on the sounding results of the antenna channel in a large-scale antenna scenario. Furthermore, the second communication device and the first communication device can seamlessly recover from the antenna selection error (for example, even if the second communication device makes an error in the PPDU sequence number information, the transmit antenna set identifier corresponding to the PPDU can also be correctly determined based on the information indicating the transmit antenna set identifier in the PPDU).

[0152] The above describes an example of a procedure for selecting a transmitting antenna in a first communication device. This embodiment of the present application may further provide a solution for selecting a receiving antenna for the first communication device. The two solutions will be described separately in detail below. Details are not provided here.

[0153] The technical solutions of the embodiments of the present application can be applied to various communication systems such as a wireless local area network (WLAN) communication system, a global system for mobile communication (GSM), a code division multiple access (CDMA) system, a wideband code division multiple access (WCDMA) system, a general packet radio service (GPRS), a long term development (LTE) system, a frequency division duplex (FDD) LTE system, a time division duplex (TDD) LTE system, a universal mobile telecommunications system (UMTS),worldwide interoperability for microwave access (WiMAX), the next generation of communication system after the 5th generation (5G) or new radio (NR).,

[0154] An application scenario of the embodiments of the present application and a method in the embodiments of the present application are described below using a WLAN system as an example.

[0155] In particular, embodiments of the present application can be applied to a wireless local area network (WLAN), and embodiments of the present application can be applied to any protocol of the IEEE 802.11 series protocols currently used in WLAN, including 802.11be, and can also be applied to a standard later than 802.11be. A WLAN may include one or more basic service sets (BSS). A network node in a basic service set includes an access point (AP) and a station (STA).

[0156] FIG. 2 is a schematic diagram of an example architecture of another system according to an embodiment of the present application. As shown in FIG. 2, the communication system includes one or more access points and may further include one or more STAs. In FIG. 1, two access points (for example, AP 201 and AP 202 shown in FIG. 2) and three STAs (for example, STA 203, STA 204, and STA 205 shown in FIG. 2) are used as an example. The first communication device 101 shown in FIG. 1 may be the AP or STA in FIG. 2. The second communication device 102 shown in FIG. 2 may be the AP or STA in FIG. 2.

[0157] The solutions presented in the embodiments of the present application are applicable to communication between access points AP, for example, to communication between AP 201 and AP 202 (Fig. 2). In this case, both the first communication device 101 and the second communication device 102 (Fig. 1) can be access points. For example, the first communication device 101 is AP 201, and the second communication device 102 is AP 202.

[0158] The solutions presented in the embodiments of the present application are further applicable to communication between STAs, for example, to communication between STA 204 and STA 205 (Fig. 2). In this case, both the first communication device 101 and the second communication device 102 in Fig. 1 may be STAs. For example, the first communication device 101 is STA 204, and the second communication device 102 is STA 205.

[0159] The solutions presented in the embodiments of the present application are further applicable to communication between one AP and one or more STAs, and are further applicable to communication between a plurality of APs and one or more STAs, for example, to communication between AP 201 and STA 203 (Fig. 2). In this case, the first communication device 101 and the second communication device 102 (Fig. 1) may be an AP and a STA, respectively. For example, the first communication device 101 is STA 203, and the second communication device is AP 201. In another example, the first communication device 101 is AP 201, and the second communication device 102 is STA 203.

[0160] The application scenario of the embodiments of the present application and the method in the embodiments of the present application are described below using an example in which the first communication device 101 is an AP and the second communication device 102 is an STA.

[0161] Furthermore, in the embodiments of the present application, the STA may also be referred to as a system, a subscriber device, an access terminal, a mobile station, a remote station, a remote terminal, a mobile device, a user terminal, a terminal, a wireless communication device, a user agent, a user device, or a user equipment (UE). The STA may be a cellular phone, a cordless phone, a phone with a session initiation protocol (SIP), a wireless local loop (WLL), a personal digital assistant (PDA), a portable device having a wireless local area network (e.g., Wi-Fi) communication function, a wearable device, a computing device, or another processing device connected to a wireless modem.

[0162] The station may be a wireless communication chip, a wireless sensor, a wireless communication terminal, etc. For example, the station may be a tablet computer supporting the Wi-Fi communication function, a set-top box supporting the Wi-Fi communication function, a smart TV supporting the Wi-Fi communication function, an intelligent wearable device supporting the Wi-Fi communication function, a vehicle-mounted communication device supporting the Wi-Fi communication function, a computer supporting the Wi-Fi communication function, etc. If necessary, the station can support the 802.11be standard. Alternatively, the station may support multiple 802.11 family wireless local area network (WLAN) standards, such as 802.11ax, 802.11ac, 802.11n, 802.11g, 802.11b, 802.11a, and the next generation 802.11be.

[0163] The access point in this application may be an extremely high throughput (EHT) STA or may be an STA to which a Wi-Fi standard of a specific generation will be applicable in the future.

[0164] In the embodiments of the present application, the AP can be configured to: communicate with an access terminal (e.g., STA) using a wireless local area network and transmit data from the access terminal to the network side, or transmit data from the network side to the access terminal. The AP is also called a wireless access point, an access point, and the like. APs are access points for mobile users to wired networks and are mainly deployed in homes, buildings, industrial and administrative complexes, or in open areas. The AP is equivalent to a bridge that connects a wired and wireless network. The main function of the access point is to connect wireless network clients together, and then connect the wireless network to the Ethernet. In particular, the AP can be a communication server, a router, a switch, a bridge, a computer, a mobile phone, and the like with a chip based on the wireless fidelity (Wi-Fi) standard.If necessary, the AP can be a device that supports multiple WLAN standards, such as 802.11.

[0165] Wireless communication can be implemented between the AP and each STA according to different standards. For example, wireless communication between the AP and STA can be implemented using single-user multiple-input multiple-output (SU-MIMO) technology or multi-user multiple-input multiple-output (MU-MIMO) technology.

[0166] For example, the access point and station may be devices used in the Internet of Vehicles (IoT) network; IoT nodes, sensors, etc. in the Internet of Things (IoT); smart cameras, smart remote controls, smart water meters, or smart electricity meters in a smart home; sensors in a smart city; or so on.

[0167] The communication device provided in the embodiments of the present application may be a wireless communication device that supports parallel transmission over multiple communication lines, for example, a device called a multi-link device or a multi-band device. Compared with a device that only supports single-link transmission, a multi-link device has higher transmission efficiency and higher throughput.

[0168] A multi-link device includes one or more affiliated STAs. A child station is a logical station and can operate on a single channel. A child station can be an Access Point (AP) or a non-Access Point Station (non-AP STA). For ease of description, a multi-link device whose child station is an AP may be called a multi-link AP, multi-channel AP device, or AP multi-link device; and a multi-link device whose child station is a non-AP STA may be called a multi-link STA, multi-channel STA, or STA multi-link device.

[0169] Figure 3 is a schematic diagram of an example of the structure of a communication device according to an embodiment of the present application. The communication device shown in Figure 3 may be shown as a schematic diagram of the internal structure of the first communication device 101 shown in Figure 1, a schematic diagram of the internal structure of the second communication device 102 shown in Figure 1, a schematic diagram of the internal structure of an AP (for example, AP 201 or AP 202 shown in Figure 2) shown in Figure 2, or a schematic diagram of the internal structure of an STA (for example, STA 203, STA 204, or STA 205 shown in Figure 2) shown in Figure 2. The communication device shown in Figure 3 may include a plurality of antennas and may be a device with more than two antennas.

[0170] As shown in Fig. 3, the communication device includes a physical layer (PHY) processing circuit, a media access control (MAC) processing circuit, a memory, a controller, a scheduler, and a processor.

[0171] The physical layer processing circuit may be configured to process a physical layer signal. The MAC layer processing circuit may be configured to process a MAC layer signal. The memory may be configured to store signaling information, etc. The controller is a control component. The scheduler is a scheduling component. The processor may be configured to analyze signaling information, process related data, etc.

[0172] It is understood that the processor in the embodiments of the present application may be a central processing unit (CPU) or may be another general-purpose processor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA) or other programmable logic device, a transistor logic device, a hardware component, or any combination thereof. The general-purpose processor may be a microprocessor, any conventional processor, etc.

[0173] The method steps in the embodiments of the present application may be implemented in hardware or may be implemented by executing software instructions using a processor. The software instructions may include a corresponding software module. The software module may be stored in random access memory, flash memory, read-only memory, programmable read-only memory, erasable programmable read-only memory, electrically erasable programmable read-only memory, a register, a hard disk, a removable hard disk, a compact disc, or any other form of storage medium known in the art. For example, the storage medium is connected to the processor so that the processor can read information from the storage medium and write information to the storage medium. Of course, the storage medium may be a component of the processor.The processor and storage medium may be located in an ASIC.

[0174] Based on the above content, Fig. 4 is a schematic diagram of an example of signal interaction of an antenna channel sounding method according to an embodiment of the present application.

[0175] In Fig. 4, the interaction between the first communication device and the second communication device is used for illustration purposes. In this embodiment of the present application, the first communication device may also be referred to as an antenna selection transmitter, and the second communication device may also be referred to as an antenna selection transponder.

[0176] The first communication device shown in Fig. 4 may be the first communication device shown in Fig. 1, may be the AP or STA shown in Fig. 2, or may be the communication device shown in Fig. 3. The second communication device shown in Fig. 4 may be the second communication device shown in Fig. 1, may be the AP or STA shown in Fig. 2, or may be the communication device shown in Fig. 3. The first communication device and the second communication device in Fig. 4 may be simultaneously an AP, simultaneously an STA, or, respectively, an AP and an STA. In Fig. 4, an example is used for presentation in which the first communication device is an AP, and the second communication device is an STA.

[0177] The solution provided in this embodiment of the present application is applicable to a procedure of sounding a transmit antenna channel between an AP and one STA, or is applicable to a procedure of sounding a transmit antenna channel between an AP and multiple STAs. Fig. 4 shows a schematic diagram of an example in which a procedure of sounding a transmit antenna channel is performed between an AP and multiple STAs (for example, STA 203, STA 204, and STA 205 in Fig. 4).

[0178] As shown in Fig. 4, the method includes the following steps.

[0179] S401: The first communication device transmits a first frame to the second communication device, wherein the first frame includes first indicator information, and the first indicator information instructs the second communication device to perform channel probing of the transmitting antenna.

[0180] Accordingly, the second communication device receives the first frame from the first communication device.

[0181] S402: The first communication device transmits the first physical protocol data unit (PPDU) to the second communication device. The first PPDU is used by the second communication device to perform channel sounding of the transmit antenna. The first PPDU includes a first identifier field. The first identifier field specifies the identifier of the first set of transmit antennas.

[0182] Accordingly, the second communication device receives the first PPDU from the first communication device.

[0183] In a possible implementation, in step S402, the first communication device may transmit one or more PPDUs after sending the first frame and after a short inter-frame space (SIFS), and adjacent PPDUs may also be spaced by the SIFS. In the figure, the SIFS is used as an example, and other durations, such as 25 microseconds, may be used. This is not limited to the solutions of the present invention. The first PPDU is one of one or more PPDUs sent by the first communication device in step S402. In this embodiment of the present application, the PPDU may also be referred to as a physical layer data packet, that is, a physical layer data packet.

[0184] In a possible implementation, the first PPDU in step S402 may be a PPDU including a data field.

[0185] In another possible implementation, the first PPDU in step S402 may not include a data field. For example, the first PPDU is a null data packet (NDP), which does not include a data field. An NDP does not include a data field, is a special example of a PPDU, and can generally be used for channel sounding. Since an NDP does not include a data field, using an NDP as the first PPDU can reduce the amount of overhead. In particular, in a large-scale antenna scenario, since there are a large number of antenna sets, there are also a large number of first PPDUs for channel sounding of a transmit antenna, and accordingly, the amount of overhead for selecting a transmit antenna increases. However, in this solution, in which channel sounding of a transmit antenna is performed based on an NDP, the amount of overhead in a large-scale antenna scenario can be further reduced.

[0186] In a possible implementation, the first communication device can transmit one or more PPDUs to the second communication device. The first PPDU is one of one or more PPDUs. The PPDU in one or more PPDUs can include a first PPDU identifier field, and the first PPDU identifier field in the one or more PPDUs indicates the identifier of the set of transmit antennas corresponding to the PPDU. For example, since the first PPDU is used to perform channel sounding of the transmit antenna in the first set of transmit antennas, the first identifier field in the first PPDU indicates the identifier of the first set of transmit antennas. As another example, if another PPDU, different from the first PPDU in one or more PPDUs, is a PPDU used to perform channel sounding of the transmit antenna in the second set of transmit antennas, the first identifier field in the PPDU indicates the identifier of the second set of transmit antennas.

[0187] In this embodiment of the present application, the PPDU transmitted by the first communication device to the second communication device can also be considered as a sounding PPDU used to perform antenna channel sounding. The second communication device can perform transmit antenna channel sounding based on the received one or more PPDUs to obtain a transmit antenna channel sounding result.

[0188] Furthermore, the second communication device may select a set of transmit antennas based on the obtained transmit antenna channel sounding result and indicate the identifier of the selected set of transmit antennas to the first communication device. For example, step S403 is performed after step S402.

[0189] S403: The second communication device transmits a second frame. The second frame includes the first antenna selection feedback result, and the first antenna selection feedback result includes a third identifier field. The third identifier field indicates the identifier of the first set of transmit antennas.

[0190] It should be noted that the third identifier field in step S403 may contain an identifier of the set of transmit antennas selected by the second communication device. For example, if the set of transmit antennas selected by the second communication device is the first set of transmit antennas, the third identifier field may indicate the identifier of the first set of transmit antennas. In this embodiment of the present application, an example is used for presentation in which the set of transmit antennas selected by the second communication device is the first set of transmit antennas. In actual application, the second communication device may also select another set of transmit antennas (in this case, the third identifier field should indicate another set of transmit antennas). This case is not limited in this embodiment of the present application.

[0191] In a possible implementation, in step S403, the second communication device performs channel probing of the transmitting antenna based on the first PPDU to obtain a first antenna selection feedback result, and the first antenna selection feedback result is carried in a second frame for sending.

[0192] Accordingly, the first communication device receives the second frame from the second communication device.

[0193] In this embodiment of the present application, the second communication device performing the channel sounding of the transmitting antenna may be a device with antenna selection capability (ASEL). The transmitting side with antenna selection capability (e.g., the first communication device) may perform the ASEL channel sounding using the NDP sounding PPDU, i.e., in English, "the ASEL transmitter uses NDP sounding PPDUs for the ASEL sounding." Alternatively, the second frame may be ASEL feedback.

[0194] In a possible implementation, after step S402, one or more second communication devices may perform channel sounding of the transmit antenna based on the first PPDU to obtain an antenna selection feedback result. In step S403, one second communication device is used as an example of description. For the sake of distinction, the antenna selection feedback result of the transmit antenna of STA 203 (the second communication device) in Fig. 4 is called the first antenna selection feedback result.

[0195] It should be noted that the antenna selection feedback results transmitted via the feedback channel by different second communication devices may be different or may be the same. This case is not limited in this embodiment of the present application. Alternatively, it is obvious that the sets of transmit antennas of the first communication device selected by different second communication devices may be different or may be the same. This case is not limited in this embodiment of the present application. For example, in FIG. 4, STA 203 (the second communication device) selects the first set of transmit antennas, and STA 204 may select the first set of transmit antennas or may select another set of transmit antennas.

[0196] From the above, it is obvious that in this embodiment of the present application, since the PPDU includes the first identifier field indicating the identifier of the first set of transmit antennas, the second communication device determines the correspondence between the channel sounding result of the transmit antenna corresponding to the PPDU and the identifier of the set of transmit antennas, and the second communication device can determine the identifier of the set of transmit antennas selected based on one or more channel sounding results of the transmit antennas. This makes it possible to prevent the second communication device from incorrectly matching the channel sounding result of the selected transmit antenna with the set of transmit antennas and to perform antenna selection based on the channel sounding results of the antenna in a large-scale antenna scenario.

[0197] With reference to Fig. 4, a further description will be given. In step S402, the first communication device may transmit one or more PPDUs to the second communication device, which are used by the second communication device to perform channel sounding of the transmit antenna. Each PPDU may correspond to a set of antennas from a group of transmit antennas. The set of antennas of each group of transmit antennas corresponds to one antenna set identifier (designated as an antenna set identifier (ID) in Fig. 4).

[0198] The antenna set identifiers shown in Fig.4 are antenna set identifiers that are 0, 1, ... and R. R can be a positive integer. The PPDUs shown in Fig.4 are PPDU (i0), PPDU (i1), ... and PPDU (i R). As shown in Fig. 4, the first communication device transmits a PPDU (i0) using the transmit antenna set whose antenna set ID is 0. The second communication device performs transmit antenna channel sounding based on the PPDU (i0) to obtain a transmit antenna channel sounding result corresponding to the transmit antenna set whose antenna set ID is 0. Similarly, the first communication device transmits a PPDU (i1) using the transmit antenna set whose antenna set ID is 1,..., and the first communication device transmits a PPDU (i R) using a set of transmitting antennas whose antenna set ID is equal to R. The second communication device receives a transmitting antenna channel sounding result corresponding to the set of transmitting antennas whose antenna set ID is 1,..., and a transmitting antenna channel sounding result corresponding to the set of transmitting antennas whose antenna set ID is equal to R. In addition, the second communication device can select a set of transmitting antennas of the first communication device based on R results of the transmitting antenna channel sounding, for example, select a first set of transmitting antennas, and then indicate the selected first set of transmitting antennas to the first communication device, so that the first communication device transmits data to the second communication device using the first set of transmitting antennas.

[0199] The arrangement of antenna set identifiers in Fig. 4 is just an example. During actual application, the antenna set identifiers corresponding to successive PPDUs sent by the first communication device may be arranged randomly, for example, arranged non-sequentially or not in ascending order. For example, the first communication device may sequentially send PPDU (i1) using the transmit antenna set whose antenna set ID is 1, PPDU (i R ), using the set of transmit antennas whose antenna set ID is R, PPDU (i0), using the set of transmit antennas whose antenna set ID is 0, and so on.

[0200] The following describes the corresponding contents of the identifiers of the set of transmission antennas mentioned in this embodiment of the present application.

[0201] In a possible implementation, the first communication device includes k1 sets of transmit antennas. k1 is a positive integer. R in Fig. 4 may be a positive integer not greater than k1. R may be equal to k1 or may be less than k1. The sets of k1 transmit antennas are in one-to-one correspondence with the identifiers of the sets of k1 transmit antennas. In other words, one of the k1 sets of transmit antennas corresponds to one of the identifiers of the k1 sets of transmit antennas, and one of the identifiers of the k1 sets of transmit antennas corresponds to one of the k1 sets of transmit antennas. The identifiers of two sets of transmit antennas corresponding to any two sets of transmit antennas may be different. The two sets of transmit antennas corresponding to the identifiers of any two sets of transmit antennas may be different. The first set of transmit antennas is one of the k1 sets of transmit antennas. An example using the first set of transmit antennas is described below.

[0202] There are many implementations of transmit antenna set identifiers. Descriptions are provided individually as follows.

[0203] Implementation a1

[0204] In a possible implementation, the identifier of the first set of transmit antennas may be a sequence number of the first PPDU corresponding to the first set of transmit antennas.

[0205] In the implementation a1, the first identifier field may indicate the rank of the first PPDU in the R PPDUs sent by the first communication device. When the PPDU transmitted by the first communication device in step S402 is an NDP, it is also obvious that the first identifier field may indicate the rank of the current NDP in the R NDPs sent by the first communication device. Therefore, the second communication device can determine the correspondence between the first PPDU and the antenna selection feedback result of the transmitting antenna based on the sequence number corresponding to the first PPDU indicated by the first identifier field, so that the second communication device can indicate to the first communication device the sequence number of the PPDU corresponding to the set of transmitting antennas selected by the second communication device (for example, the second communication device selects the first set of transmitting antennas).In this way, the first communication device correctly determines, based on the PPDU sequence number transmitted over the feedback channel by the second communication device, the set of transmit antennas selected by the second communication device, thereby implementing the antenna selection decision based on the antenna channel probing result in the large-scale antenna scenario.

[0206] Implementation a2

[0207] In another possible implementation, the identifier of the first set of transmit antennas may be a group identifier of the first set of transmit antennas.

[0208] The first communication device can obtain a correspondence between the transmit antenna set and the group identifier of the transmit antenna set. Thus, when the first communication device transmits a PPDU in step S402, it can carry pointer information indicating the identifier of the transmit antenna set corresponding to the PPDU.

[0209] The second communication device may obtain a correspondence between the set of transmit antennas and the group identifier of the set of transmit antennas, or may not obtain (or not learn) a correspondence between the set of antennas and the group identifier of the set of transmit antennas. Since the PPDU received by the second communication device carries pointer information indicating the identifier of the set of transmit antennas corresponding to the PPDU, regardless of whether the second communication device learns the correspondence between the set of antennas and the group identifier of the set of transmit antennas, the second communication device can determine the correspondence between the feedback result of selecting the set of antennas corresponding to the PPDU and the set of transmit antennas, so that the second communication device can indicate to the first communication device the identifier of the set of transmit antennas corresponding to the set of transmit antennas selected by the second communication device (for example, the second communication device selects the first set of transmit antennas).In this way, the first communication device correctly determines, based on the identifier of the set of transmitting antennas transmitted via the feedback channel by the second communication device, the set of transmitting antennas selected by the second communication device, thereby selecting an antenna based on the result of probing the antenna channel in the large-scale antenna scenario.

[0210] The antenna set identifier may further include the following possible implementations:

[0211] Implementation a2-1

[0212] The first communication device and the second communication device can perform negotiation. The first communication device can notify the second communication device of the total number of sets of transmit antennas supported by the first communication device through the negotiation. For example, the first communication device transmits the ninth frame to the second communication device. The ninth frame includes seventh indicator information. The seventh indicator information indicates the total number of sets of transmit antennas supported by the first communication device. The ninth frame can be an MPDU. Thus, the second communication device can estimate the overhead data and the duration of the transmit antenna selection procedure based on the seventh indicator information; and the second communication device can further determine, based on the total number of sets of transmit antennas supported by the first communication device, whether to establish an association relationship using the first communication device.

[0213] The first communication device may set a transmit antenna set group identifier for a transmit antenna set supported by the first communication device. The second communication device may not obtain (or know) the correspondence between the antenna set and the transmit antenna set group identifier.

[0214] Since transmit antenna sets are in a one-to-one correspondence with transmit antenna set identifiers, the second communication device receives two PPDUs at different times that include the same antenna set identifier. If the detected channel changes, since the antenna set identifiers included in the two PPDUs are the same, the second communication device can determine that the channel itself has changed.

[0215] Implementation a2-2

[0216] In this embodiment of the present application, the correspondence between the set of transmit antennas and the group identifier in the first communication device may be predetermined (for example, may be specified in a standard). The correspondence may be predetermined in the first communication device or may be sent by another communication device to the first communication device. Thus, the first communication device can learn the identifier of the set of transmit antennas for each set of transmit antennas, so that the identifier of the set of transmit antennas is carried during sending.

[0217] The mapping may not be preset in the second communication device, may be preset in the second communication device, or may be sent by another communication device to the second communication device. Thus, the second communication device can determine the antennas specifically included in the identifier of the first transmit antenna set based on the identifier of the first transmit antenna set specified by the first identifier field in the received first PPDU. In addition, since the transmit antenna sets are in a one-to-one correspondence with the identifiers of the transmit antenna sets, the second communication device receives two PPDUs including the same antenna set identifier at different times. If the detected channel changes, since the identifiers of the antenna sets included in the two PPDUs are the same, the second communication device can determine that the channel itself changes.In addition, the second communication device may further determine a specific set of transmit antennas corresponding to the identifier of the set of transmit antennas in order to obtain more information related to the communication link, thereby providing assistance for another subsequent procedure.

[0218] Implementation a2-3

[0219] The first communication device and the second communication device agree on determining a group identifier of the first set of transmit antennas.

[0220] The first communication device and the second communication device can perform negotiation. The second communication device learns the set of transmit antennas supported by the first communication device; and after negotiation, the first communication device and the second communication device establish a group identifier for the set of transmit antennas supported by the first communication device.

[0221] For example, a first communication device transmits a fourth frame to a second communication device. The second communication device receives the fourth frame. The fourth frame may be an MPDU. The fourth frame includes a fourth identifier field. The fourth identifier field indicates the identifier of at least one set of transmit antennas supported by the first communication device. The identifier of the at least one set of transmit antennas includes the identifier of the first set of transmit antennas.

[0222] Thus, the first communication device can learn the identifier of the transmit antenna set for each transmit antenna set, so that the identifier of the transmit antenna set is carried during transmission. In addition, the second communication device can determine the antennas specifically included in the identifier of the first transmit antenna set based on the identifier of the first transmit antenna set indicated by the first identifier field in the received first PPDU. Obviously, the second communication device can obtain more information related to the antenna set through negotiation, and can subsequently obtain more information related to the communication link, thereby further providing assistance for other subsequent procedures.

[0223] It should be noted that implementation a1 and implementation a2 can be implemented separately or combined. For example, the identifier of the first set of transmit antennas can include the sequence number of the first PPDU corresponding to the first set of transmit antennas and the group identifier of the first set of transmit antennas. This allows for more precise identification of the first set of transmit antennas and increased solution flexibility.

[0224] In this embodiment of the present application, the identifier of the first set of transmit antennas may be indicated by one or more symbols or may be indicated by one or more bits, for example, may be indicated by one or more bits corresponding to a binary format. The information carried in the first identifier field may be all or some of the bits corresponding to the identifier of the first set of transmit antennas. Descriptions are given separately as follows.

[0225] Implementation b1

[0226] The first identifier field includes all bits corresponding to the identifier of the first set of transmit antennas. In other words, the first identifier field contains all bits corresponding to the identifier of the first set of transmit antennas. Thus, the second communication device can uniquely determine the identifier of the transmit antenna set based on the first identifier field contained in the PPDU.

[0227] Implementation b2

[0228] The bits in the PPDU preamble are considered valuable, and to reduce the number of bits used in the PPDU preamble, the first identifier field includes some bits corresponding to the identifier of the first set of transmit antennas. This can reduce the number of bits occupied by the first identifier field in the PPDU. However, this implementation may have the following cases:

[0229] When there are a large number of transmit antenna sets, since the first identifier field carries only some bits corresponding to the identifier of the first transmit antenna set, there may be two PPDUs in the plurality of PPDUs sent by the first communication device, and the fields indicating the identifiers of the transmit antenna sets in the two PPDUs may carry the same content.

[0230] In this case, multiple implementations are possible: For example, the first communication device carries all the bits of the identifier of the transmit antenna set corresponding to the PPDU in the first frame. Thus, the second communication device can determine all the bits of the identifier of the transmit antenna set corresponding to the PPDU based on the rank of the received PPDU and the field indicating the identifier of the transmit antenna set in the PPDU. Thus, the second communication device can indicate to the first communication device all the bits of the identifier of the selected first transmit antenna set.

[0231] As another example, the second communication device may transmit, via a feedback channel, to the first communication device, a rank of the PPDU corresponding to the selected set of transmit antennas, and some bits corresponding to the identifier of the first set of transmit antennas carried in the PPDU, so that the first communication device determines the first set of transmit antennas based on the rank of the sent PPDU and some bits corresponding to the identifier of the first set of transmit antennas.

[0232] Based on the above content, Fig. 5 is a schematic diagram of an example of signaling interaction of the antenna channel sounding method according to the embodiment of the present application. In Fig. 5, steps S501 and S502 are added based on Fig. 4. It should be noted that steps S501 and S502 are additional steps and are not necessary. After step S502, the first communication device may perform steps S401 and S402, and the second communication device may perform step S403. Below, a frame in this embodiment of the present application is further described with reference to the schematic diagram of signaling interaction shown in Fig. 5.

[0233] As shown in Fig. 5, the method includes the following steps.

[0234] S501: The first communicating device transmits the first trigger frame.

[0235] The first trigger frame can be used to notify the second communication device that receive antenna selection needs to be performed.

[0236] S502: The second communication device transmits the third frame. The third frame includes the third pointer information. The third pointer information is used to request channel probing of the transmit antenna.

[0237] Accordingly, the first communication device receives the third frame.

[0238] In this embodiment of the present application, the second communication device may transmit a third frame based on the activation of the first trigger frame in step S501, or may independently transmit the third frame. This case is not limited in this embodiment of the present application. For the sake of distinction, in Fig. 5, the frame that belongs to STA 203 (the second communication device) and that is used to request the first communication device to send information for performing the channel sounding of the transmit antenna is called the third frame. For another frame that is transmitted by the second communication device and that is used to request the first communication device to send information for performing the channel sounding of the transmit antenna, refer to the corresponding description of the third frame.

[0239] The third frame may be referred to as a transmit antenna selection sounding request. In another possible implementation, it is also obvious that the third indicator information instructs the first communication device to transmit information for performing transmit antenna channel sounding. The information for performing transmit antenna channel sounding can be regarded as a continuous sounding PPDU.

[0240] The third frame may further include a certain number of PPDUs that the first communication device requests to be sent. Thus, the first communication device can determine, based on the number of PPDUs carried in the third frame, the number of PPDUs to be subsequently transmitted. The first communication device can then determine, based on the requirement of the second communication device, the number of PPDUs subsequently sent, and the number of PPDUs to be subsequently transmitted by the first communication device corresponds as closely as possible to the requirement of the second communication device. The number of PPDUs sent by the first communication device may be the same as or different from the number of PPDUs requested in the third frame to be sent by the first communication device.

[0241] In WLAN, APs and STAs can transmit control signaling, coordination signaling, or data using a Media Access Control (MAC) Protocol Data Unit (MPDU) (or MAC frame for short). A third frame can be carried in the MPDU, in which the MAC frame header carries the High Throughput Control (HTC) field.

[0242] Figure 6 shows a schematic diagram of an example of the structure of an MPDU that can carry a third frame, according to an embodiment of the present application. As shown in Figure 6, the MPDU may include a frame header, a frame body, and a frame check sequence. The frame header may include frame control corresponding to address information, sequence control information, and the like. The frame body may carry data or control and management information transmitted from an upper layer. The frame check sequence (FCS) may be used to check the correctness of the MPDU transmission.

[0243] As shown in Fig. 6, the MPDU includes a high-throughput (HT) control field. The HT control field is divided into three variants: high-throughput variant, very-high-throughput variant, and high-efficiency variant. The variant related to the third frame is a high-efficiency variant, or can be regarded as the third pointer information being carried in the high-efficiency variant field of the third frame.

[0244] The high-performance variant HT control field includes an Aggregated Control (A-control) subfield, that is, the A-Control subfield in the HT control field of the HE variant, or is called "the format of the A-Control subfield of the HE variant HT Control field".

[0245] The A-Control subfield can carry from one to N1 pieces of control information using a structure of one or more control identifier fields and a control information field. N1 can be a positive integer. In the example shown in Fig. 6, N1 is an integer greater than 2. The control identifier field can indicate the type of control information or determine the length of the corresponding control information. The antenna selection command field and the antenna selection data field can be obtained by separating the control information field. The third indicator information is carried in at least one of the control identifier field, the antenna selection command field, or the antenna selection data field in the A-control subfield.

[0246] In this embodiment of the present application, the control identifier value of the control identifier field, which is not used in the standard, can be used to indicate the transmit antenna selection procedure in this embodiment of the present application. For example, the control identifier value of the control identifier field can be one of 9 or 11-14. In this case, the length of the control information field can be a maximum of 26 bits.

[0247] The number of bits occupied by the antenna selection command field and the antenna selection data field may be greater than 7. The number of bits occupied by the antenna selection command field and the antenna selection data field does not exceed 26. The number of bits occupied by the antenna selection data field may be greater than 4.

[0248] In this embodiment of the present application, the antenna selection command field and the antenna selection data field shown in Fig. 6 can be set based on actual needs. Table 1 shows an example of a possible antenna selection command field and an antenna selection data field. The content of the second row of Table 1 is used as an example for the description. As shown in Table 1, when the antenna selection command field is 0, it indicates that the current frame is used to perform channel sounding of the transmit antenna, and the antenna selection data field can indicate the number of remaining untransmitted PPDUs. The content of other rows is only an example and is not described here.

[0249] Table 1. Example of possible antenna selection command field and antenna selection data field

[0250] Antenna selection command field Meaning of the antenna selection command Antenna Selection Data Field (more than 4 bits) 0 Transmit the transmit antenna selection probe pointer Indicates the number of remaining untransmitted sounding PPDUs. 1 Transmit a request for transmit antenna selection or resumption of transmit antenna selection probing Indicates 0 when the antenna select command is a request to select a transmit antenna. 2 Accept the receiving antenna selection probe pointer Specifies the number of remaining probing PPDUs to be received. 3 Accept the request to select a receiving antenna Specifies the number of required probing PPDUs. 4 Sounding Label Sequence number of the sounding PPDU corresponding to the channel state information frame during antenna selection feedback 5 No feedback signal due to incorrect antenna selection or feedback signal delay Sequence number of the first sounding PPDU that was received incorrectly. 0 indicates the first sounding PPDU in the antenna selection training sequence, that no sounding PPDU was received correctly, or that the entire retraining sequence was requested. 6 Send transmit antenna selection probe pointer: Request detailed channel status information Indicates the number of remaining untransmitted sounding PPDUs. 7 Reserved Reserved

[0251] It is obvious that in the embodiment of the antenna selection procedure based on the High Throughput Control (HTC) field in 802.11n, a maximum of four RF chains, eight antennas, and 16 antenna sets are supported. In the embodiments of the present application, since the number of bits in the control information field is large, the MPDU shown in Fig. 6 can contain more types of antenna selection commands, and the antenna selection data field also has more than 4 bits. Therefore, more PPDUs (more than 16 PPDUs can be supported) and more antenna sets (more than 16 antenna sets can be supported) can be supported.In addition, since the antenna selection command field and the antenna selection data field are obtained by splitting in the existing standard, the antenna selection command field and the antenna selection data field are also obtained by splitting the A-control subfield into a high-performance variant field so that the present application can achieve higher compatibility with the command form in the existing standard.

[0252] In step S401, the first communication device may transmit a first frame based on the third frame sent by the second communication device, or may independently transmit the first frame. This case is not limited in this embodiment of the present application. The first frame may be a frame including first indicator information indicating that the second communication device should perform channel sounding of the transmit antenna. For example, the first frame may be a null data packet announcement (NDPA) frame.

[0253] The first frame includes first indicator information. The first frame may additionally include a number of NDPs and / or a second identifier field. The second identifier field indicates the identifier of the first set of transmit antennas. Thus, the second communication device can determine, based on the first frame, the number of NDPs that need to be received subsequently to check for missing NDPs.

[0254] In a possible implementation, when the NDPA frame includes a second identifier field, the second identifier field may include all the bits corresponding to the identifier of the first set of transmit antennas. Therefore, the first identifier field in the first PPDU subsequently sent by the first communication device may carry some bits corresponding to the identifier of the first set of transmit antennas. Therefore, the number of bits occupied by the first identifier field in the first PPDU can be reduced, and the second communication device can determine, based on the second identifier field and the first identifier field, all the bits of the identifier of the first set of transmit antennas corresponding to the first PPDU.

[0255] Figure 7 shows a schematic diagram of an example of the structure of the first frame, when the first frame is an NDPA frame, according to an embodiment of the present application. The second identifier field and the number of NDPs are not necessarily included in the NDPA frame. In Figure 7, an example is used for the presentation in which the first frame includes the second identifier field, the number of NDPs, and the first pointer information.

[0256] As shown in Fig. 7, the NDPA frame may include a Frame Control, a Duration, a receiver address, a transmitter address, a sounding dialog token, and one or more pieces of station information (for example, STA Info 1, STA Info 2, STA Info 3, ..., and STA Info N2 shown in Fig. 7), and may further include a frame check sequence.

[0257] In this embodiment of the present application, a specific association identifier of the station information field may indicate that the information in the station information field is information related to antenna selection. For example, at least one of the first indicator information, the number of NDPs, or the second identifier field may be carried in at least one station information field that relates to the first frame and that includes the second indicator information. The second indicator information indicates that the station information field includes information related to antenna selection. Thus, when the second indicator information is identified, the second communication device can determine that the station information field carrying the second indicator information carries information related to antenna selection, and then obtain the information related to antenna selection from the station information field.The second indicator information may distinguish a station information field carrying information related to antenna selection from a station information field corresponding to another legacy station, so that in a solution in which the station information field carries information related to antenna selection, the station information field corresponding to the legacy station is not affected, and compatibility with the existing standard is achieved.

[0258] The second indicator information can be carried in the association identifier field of the station information field. The second indicator information includes one of the numbers from 2008 to 2043 or 2046. For example, when the association identifier field has one of the values ​​from 2008 to 2043 or 2046, it indicates that the information related to the antenna selection is carried in the station information field. In this way, the second communication device can determine, based on the association identifier field, whether the station information field carries the information related to the antenna selection or the station information corresponding to another second communication device. Obviously, this solution can ensure higher compatibility with the conventional technology. In Fig. 7, an example is used for presentation in which the station information field 1 and the station information field 2 contain the information related to the antenna selection.

[0259] The first indicator information may also be referred to as an antenna selection type, an NDPA antenna selection option indicator information, or an NDPA frame option subtype. The first indicator information further indicates that the NDPA frame option is an antenna selection option. Typically, to perform antenna selection, the NDPA frame indicating the second communication device is followed by multiple (more than one) NDPs, and to perform channel sounding, the NDPA frame indicating the second communication device is followed by one NDP. The number of NDPs following the NDPA frame affects the reception time of the second communication device of the NDP and the feedback time of the second communication device. Thus, in this embodiment of the present application, the first indicator information can indicate to the second communication device that the NDPA frame option is an antenna selection option.Additionally, information (second pointer information) carried in the specific association identifier field can also have a similar effect. In other words, after the second communication device identifies a specific association identifier (second pointer information), since the second pointer information indicates that the station information field includes information related to antenna selection, the second communication device can also determine, based on the second pointer information, that the NDPA frame variant is an antenna selection variant.

[0260] The NDPA frame with the HT management field is no longer supported in the 802.11ax-802.11be standards. In this embodiment of the present application, the relevant information related to antenna selection is carried in the station information field of the NDPA frame, so that the information necessary for antenna selection can be specified. In addition, the association identifier in the association identifier field of the station information field is a special association identifier, and a plurality of second communication devices can read the content of the station information field.

[0261] Figure 7 further shows a schematic representation of the information carried in the regular station information field. In Figure 7, an example is used for the representation in which the N2 station information field carries information about the regular station. N2 can be an integer greater than 1. As shown in Figure 7, the association identifier field of the N2 station information field contains the association identifier of the station. The N2 station information field may further include partial bandwidth information (Partial BW Info) to indicate the resource used by the STA for transmitting channel state information over the feedback channel. The resource may be a segment of consecutive RUs designated by an index from the start index of a resource unit (RU) to the end index of another RU. In addition, the number of groupings (Ng) indicates that Ng subcarriers are grouped into one group.Channel state information can be transmitted over the feedback channel for a group of subcarriers in a unified manner to reduce the number of bits required for transmission over the feedback channel. The codebook size subfield indicates the quantization precision. Different precisions correspond to different amounts of overhead.

[0262] In this embodiment of the present application, the first frame may further indicate which one or more second communication devices perform the transmit antenna channel sounding. For example, the association identifier field of the station information field in the NDPA frame may carry the association identifier of the second communication device that needs to perform the transmit antenna channel sounding. When the second communication device determines that its own association identifier matches the association identifier carried in the association identifier field in the NDPA frame, the second communication device may determine that it needs to perform the transmit antenna channel sounding.

[0263] The number of bits of each field shown in Fig. 7 is used as an example, and in the solutions of the present invention, a specific number of bits is not limited. In this embodiment of the present application, the NDPA frame structure used in the current IEEE 802.11ac, IEEE 802.11ax, or IEEE 802.11be standards can be additionally used for the NDPA frame. Alternatively, a new NDPA frame can be further redefined, and the corresponding information is carried in a newly defined common field.

[0264] In step S402, the first PPDU transmitted by the first communication device may not include a data field, such as an NDP, or may include a data field. Fig. 8a and Fig. 8b show a schematic diagram of an example of the structure of the first PPDU when the first PPDU is an NDP. Fig. 8c shows a schematic diagram of an example of the structure of the first PPDU including a data field. Descriptions are given below separately with reference to the accompanying drawings.

[0265] In the 802.11be standard, the NDP shown in Fig. 8a may be a sounding PPDU. The NDP shown in Fig. 8a may be an EHT sounding PPDU, which is also called an EHT sounding NDP (EHT sounding NDP) or an EHT NDP. The EHT sounding NDP is a transmission mode of the MU EHT PPDU and is used for channel sounding to help the first communication device obtain channel state information between the transmitting end and the receiving end in order to perform beamforming and resource scheduling.

[0266] As shown in Fig. 8a, the EHT sounding NDP may include a preamble and a packet extension (PE). The first identifier field is located in the preamble of the first PPDU.

[0267] The preamble may include a legacy preamble. The legacy preamble may include a legacy short training field (L-STF), a legacy long training field (L-LTF), and a legacy signal field (L-SIG). The legacy preamble is used to ensure coexistence between new and legacy devices. The L-SIG may include a length field and may indirectly indicate the duration following the L-SIG in the PPDU.

[0268] The preamble may further include a repeated legacy signaling field (Repeated L-SIG, RL-SIG) to enhance the reliability of the legacy signaling field. Additionally, an automatic detection method may be provided to help the second communication device identify the data packet as an EHT PPDU by detecting, at the receiving end, features such as whether two symbols are the same and the remainder of the length in the L-SIG.

[0269] The preamble may optionally include a Universal Signal Field (U-SIG), which may exist in PPDUs in 802.11be and future standards. The U-SIG may indicate that the PPDU is an EHT PPDU and a future PPDU.

[0270] The preamble may optionally include an extremely high throughput signal field (EHT-SIG) following the U-SIG. Both the U-SIG and EHT-SIG can carry signaling information necessary for demodulating the subsequent data field.

[0271] The first identifier field may include some or all of the bits in the U-SIG and / or some or all of the bits in the EHT-SIG. In the EHT sounding NDP, the U-SIG field may include two symbols, and the EHT-SIG field may include one symbol. Currently, B20–B24 of the first symbol in the U-SIG, and B14 and B15 of the EHT-SIG field are disregarded. B25 of the first symbol in the U-SIG field, and B2 and B8 of the second symbol in the U-SIG field are valid. The disregarded and valid bits represent two types of reserved bits. In this embodiment of the present application, these reserved bits in the existing standard can be used as bits in the first identifier field. In this embodiment of the present application, one or more bits in B20-B24 of the first symbol in the U-SIG field, B14 and B15 of the EHT-SIG field, B25 of the first symbol in the U-SIG field, and B2 and B8 of the second symbol in the U-SIG field may be used as bits in the first identifier field.Thus, the solution can be compatible with traditional technology.

[0272] The EHT NDP sounding module can optionally include an extremely high-throughput short training field (EHT-STF) and an extremely high-throughput long training field (EHT-LTF). The EHT-STF and EHT-LTF can be used for automatic gain control and channel estimation, respectively. Extending the packet can provide more time for the second communication device to process the data.

[0273] In Fig. 8a, the EHT sounding NDP is used as an example to describe the first PPDU. This embodiment of the present application is also applicable to the standard after the EHT, for example, it can be applicable to the next generation (NG) sounding NDP.

[0274] Figure 8b shows a schematic diagram of an example of the structure of the first PPDU, when the first PPDU is a sounding NDP NG. As shown in Figure 8b, the sounding NDP NG may include a preamble and a packet extension (PE). The first identifier field is located in the preamble of the first PPDU.

[0275] The preamble may include a legacy preamble. The legacy preamble may include a Legacy Short Training Field (L-STF), a Legacy Long Training Field (L-LTF), a Legacy Signal Field (L-SIG), a Repeated Legacy Signal Field (RL-SIG), a Universal Signal Field (U-SIG), and a Next Generation Signal Field (NG-SIG). The first identifier field may consist of some or all of the bits in the U-SIG and / or some or all of the bits in the NG-SIG. In other words, one or more bits in the U-SIG and NG-SIG are used as the first identifier field.

[0276] The NG Probing NDP may additionally include a next-generation short training field (NG-STF) and a next-generation long training field (NG-LTF). The NG-STF and NG-LTF can be used for automatic gain control and channel estimation, respectively. Extending the packet can provide more data processing time for the second communication device.

[0277] Fig. 8c shows a schematic diagram of an example of a structure in which the first PPDU includes a data field. Fig. 8c shows an example in which the data field is added taking into account Fig. 8b. The first PPDU shown in Fig. 8c can also be called an MPDU. Compared with Fig. 8b, in Fig. 8c, a data field is added to the first PPDU. The data field may include an A-control subfield. For the A-control subfield in Fig. 8c, refer to the corresponding description of the A-control subfield in Fig. 6.

[0278] The first identifier field may represent some or all bits of at least one of the U-SIG, NG-SIG, or data field. For example, the first identifier field may represent bits in the control identifier field, the antenna selection command field, and the antenna selection data field (Fig. 8c).

[0279] For example, the control identifier field can be one of 9 and 11-14. The antenna selection command field can define a new identifier to indicate that the current first PPDU is the first PPDU for channel sounding of transmit antennas. The antenna selection data field can specify the identifier of the first PPDU (for example, it can specify the sequence number of the first PPDU).

[0280] In another possible implementation, the first identifier field may additionally include some bits in the A-control subfield. For example, some bits in the A-control subfield may be marked as the first identifier field to indicate the identifier of the first PPDU.

[0281] Figure 8c shows an example in which the first PPDU is a next-generation PPDU. In this embodiment of the present application, the first PPDU may also be an EHT PPDU including a data field. For example, the first PPDU may be an EHT MPDU including a data field. In a specific form of the structure, a data field may be added to the structure shown in Figure 8a, and the data field may include an A-control subfield. With regard to the A-control subfield, reference should be made to the corresponding description of the A-control subfield in Figure 6. When the first PPDU is an EHT MPDU, the first identifier field may consist of some or all bits in at least one of: U-SIG, EHT-SIG, or a data field. For the corresponding content, see the above description. The details are not described again.

[0282] The second frame may include a MIMO control field. The MIMO control field is located in the frame body, for example, it can be carried in the body of an Action frame or an Action No ACK frame. Fig. 9 shows a schematic diagram of an example of the structure of the MIMO control field in the second frame when the second frame is a beamforming report frame. It should be noted that, to more clearly reflect the frame structure, the frame structure in Fig. 9 is divided into three lines for presentation.

[0283] As shown in Fig. 9, the third identifier field may include some or all of the bits in the MIMO control field. The third identifier field includes all bits corresponding to the identifier of the first set of transmit antennas. Thus, the first communication device can determine, based on the third identifier field in the second frame, that the set of transmit antennas selected by the second communication device is the first set of transmit antennas. In addition, the third identifier field can be added to the second frame using bits in the existing multiple-input multiple-output control (MIMO Control) field. This solution does not further increase the length of the second frame and allows for higher compatibility with conventional technology.

[0284] In a possible implementation, the third identifier field may include two parts: an antenna set identifier field and a sounding PPDU sequence number field. The antenna set identifier field may carry a group identifier of the first set of transmit antennas, and the sounding PPDU sequence number field may carry a sequence number of the first PPDU corresponding to the first set of transmit antennas. In Fig. 9, an example is used for presentation in which the third identifier field includes an antenna set identifier field and a sounding PPDU sequence number field. The third identifier field may alternatively include only one of the antenna set identifier field and the sounding PPDU sequence number field.

[0285] In another possible implementation, the second frame may additionally include an antenna selection failure feedback field. When this field value is set to 1, it indicates that the current antenna selection is unsuccessful. When this field value is set to 0, it indicates that the current antenna selection is successful. The antenna selection failure feedback field may also be carried in the MIMO control field.

[0286] In another possible implementation, the second frame may further include at least one of a compressed beamforming report, a multi-user beamforming report, and a channel quality status report. For example, the channel quality status report may include, for example, at least one of channel state information (CSI) or channel quality information (CQI) corresponding to the PPDU.

[0287] One or more of the compressed beamforming report, multi-user beamforming report, and channel quality status report may be carried in the second frame in a field different from the MIMO control field. Of course, at least one of the antenna set identifier field and the sounding PPDU sequence number field, which are included in the third identifier field, may alternatively be set in another field. For example, the sounding PPDU sequence number field may be located in the A-control subfield.

[0288] From the above content, it is clear that in this embodiment of the present application, for example, when the NDPA frame does not support the high-throughput control field, an embodiment of the antenna selection procedure based on NDPA (first frame) + NDP (PPDU) + feedback (second frame) is provided. The antenna selection procedure can correspond to the current channel sounding procedure, the devices on the receiving and transmitting sides are slightly modified, and the implementation is simple.

[0289] In addition, it should be noted that in this embodiment of the present application, the second communication device may transmit one antenna selection feedback result via a feedback channel or may transmit a plurality of antenna selection feedback results via a feedback channel.

[0290] For example, the second communication device may select a group of transmit antennas based on the entire bandwidth. In this case, the first set of transmit antennas selected by the second communication device is selected based on the entire bandwidth. As another example, the second communication device may select a group of transmit antennas based on sub-bands of the bandwidth. In this case, the first set of transmit antennas corresponds to one sub-bandwidth, that is, the first set of transmit antennas is selected based on one sub-bandwidth. Of course, the two sets of transmit antennas selected by the second communication device based on two sub-bandwidths may be the same or may be different. This case is not limited in this embodiment of the present application.

[0291] In addition, the second communication device may further separately transmit via a feedback channel selected sets of transmit antennas based on a different number of spatial streams, or may separately transmit via a feedback channel selected sets of transmit antennas based on at least one of a number of channel conditions, a signal-to-noise ratio, and the like. This case is not limited in this embodiment of the present application.

[0292] In addition, in another possible implementation, when there are multiple second communication devices, the first communication device may transmit a first trigger frame to initiate the plurality of second communication devices to transmit their respective antenna selection feedback results via the feedback channel. Furthermore, the number of bits in Fig. 9 is simply an example, and N3 is a positive integer.

[0293] Based on the above content, Fig. 10 is a schematic diagram of an example of signal interaction of an antenna channel sounding method according to an embodiment of the present application.

[0294] In Fig. 10, the interaction between the first communication device and the second communication device is used for illustration purposes. In this embodiment of the present application, the first communication device may also be referred to as an antenna selection transmitter, and the second communication device may also be referred to as an antenna selection transponder.

[0295] The first communication device shown in Fig. 10 may be the first communication device shown in Fig. 1, may be the AP or STA shown in Fig. 2, or may be the communication device shown in Fig. 3. The second communication device shown in Fig. 10 may be the second communication device shown in Fig. 1, may be the AP or STA shown in Fig. 2, or may be the communication device shown in Fig. 3. The first communication device and the second communication device in Fig. 10 may be simultaneously an AP, simultaneously an STA, or, respectively, an AP and an STA. In Fig. 10, an example is used for presentation in which the first communication device is an AP and the second communication device is an STA.

[0296] The solution provided in this embodiment of the present application is applicable to a procedure of sounding a transmit antenna channel between an AP and one STA, or is applicable to a procedure of sounding a transmit antenna channel between an AP and multiple STAs. Fig. 10 shows a schematic diagram of an example in which a procedure of sounding a transmit antenna channel is performed between an AP and multiple STAs (for example, STA 203, STA 204, and STA 205 in Fig. 10).

[0297] As shown in Fig. 10, the method includes the following steps.

[0298] S601: The first communication device transmits an eleventh frame to the second communication device, wherein the eleventh frame includes first indicator information, and the first indicator information instructs the second communication device to perform channel probing of the transmitting antenna.

[0299] Accordingly, the second communication device receives the eleventh frame from the first communication device.

[0300] S602: The first communication device transmits the third PPDU to the second communication device. The second communication device uses the third PPDU to perform channel sounding of the transmit antenna.

[0301] Accordingly, the second communication device receives the third PPDU from the first communication device.

[0302] The third PPDU may include M1 first information fields corresponding to M1 sets of transmit antennas. M1 is an integer greater than 1. The first information field is used to perform channel sounding of the transmit antenna.

[0303] S603: The second communication device transmits the antenna selection feedback result through the feedback channel.

[0304] It is obvious from the solution that in this embodiment of the present application, the first communication device can aggregate PPDUs corresponding to the sets M1 of transmitting antennas to be transmitted in step S602 into one PPDU in order to reduce the amount of overhead data, improve the efficiency of antenna selection, and increase the system throughput.

[0305] Figure 11 shows a schematic diagram of an example of the frame structure of the third PPDU. As shown in Figure 11, the third PPDU may include M1 first information fields corresponding to M1 sets of transmit antennas. M1 may be an integer greater than 1. The first information field is used to perform channel sounding of the transmit antenna.

[0306] The first information field includes at least one of a short EHT training field, a long EHT training field, and a packet extension field. Any two first information fields use different sets of transmit antennas. For example, the three sets of transmit antennas shown in Fig. 11 are, respectively, the first information field corresponding to the set of transmit antennas whose antenna set ID is 0, the first information field corresponding to the set of transmit antennas whose antenna set ID is 1, ..., and the first information field corresponding to the set of transmit antennas whose antenna set ID is M1.

[0307] As shown in Fig. 11, the third PPDU may further include a preamble. The preamble includes at least one of the following fields: L-STF, L-LTF, L-SIG, RL-SIG, U-SIG, or EHT-SIG. The corresponding description of the preamble is given in the corresponding description of Fig. 8a. The details are not described here again.

[0308] In Fig. 11, it can be seen that in step S602, M1PPDUs corresponding to M1 sets of transmit antennas that initially need to be transmitted are aggregated into one third PPDU, so that (M1–1) preambles can be shortened.

[0309] In addition, it is seen from Fig. 11 that each first information field may include one packet extension field, for example, packet extension 0 in the first information field corresponding to the set of antennas with ID=0, packet extension 1 in the first information field corresponding to the set of antennas with ID=1, ..., and packet extension M1 in the first information field corresponding to the set of antennas with ID=M1 shown in Fig. 11. The duration of any two data extensions in the packet extensions (from packet extension 0 to packet extension (M1-1)) except for the last packet extension M1 may be the same. The duration of these packet extension fields may be used to provide more processing time for the second communication device. In addition, the first communication device may provide time for switching the antenna. In addition, the duration may be set to a shorter value, and it is sufficient for the first communication device to switch the antenna.

[0310] In a possible implementation, the duration of the packet extension fields in at least the first two information fields of the M1 first information fields may be different. For example, the duration of the M1 packet extension may differ from the duration of the 1-packet extension. The duration of the M1-packet extension may be set to a slightly longer value. The duration of packet extension 1 may be set to a slightly shorter value, sufficient for the first communication device to switch the antenna. In addition, in this implementation, the duration of any two data extensions in packet extensions (from packet extension 0 to packet extension (M1-1)) except for the last packet extension M1 may be the same or may be different.

[0311] In another possible implementation, the length of the packet extension fields in any two of the M1 first information fields is the same. This can improve the compatibility of the reception procedure.

[0312] Compared with the solution in which the first communication device transmits PPDUs corresponding to M1 transmit antennas, in the solution shown in Fig. 11, it is only necessary to transmit one third PPDU to achieve the purpose of transmitting M1 information groups used to perform channel sounding of the transmit antenna. In this solution, it is possible to reduce the (M1-1) preamble groups (from L-STF to EHT-SIG) and the short inter-frame space SIFS. When the time of any two packet extensions 0 and the (M1-1) packet extension are the same, and the duration of the packet extension 0 is shorter than the duration of the M1 packet extension, the time difference between the M1 packet extension and the packet extension 0 can be further reduced.

[0313] For example, the preamble (L-STF for EHT-SIG) in the third PPDU lasts for a total of 36 microseconds, the duration of the M1 packet extension is 16 microseconds, and the SIFS lasts for 16 microseconds. If the time of any one of the 0 packet extension and the (M1-1) packet extension is 4 microseconds, and M1=64, compared with transmitting PPDUs corresponding to the M1 transmit antennas (the PPDU includes the preamble and one first information field, and the data extension field included in the first information field is 16 microseconds), in this case, 36×(64-1)+16×(64-1)+(16-4)×(64-1)=4032 microseconds can be reduced by transmitting the third PPDU.

[0314] It should be noted that Fig. 11 is just an example of the PPDU structure of a possible third PPDU. In this example, the EHT-SIG is transmitted once. In another possible implementation, the EHT-SIG may appear in groups. For example, each first information field includes one EHT-SIG. In addition, in Fig. 10, an example is used for presentation in which the first communication device transmits one third PPDU. During actual application, in step S602, the first communication device may transmit one or more third PPDUs, and the number of first information fields included in the third PPDUs may be the same or different.

[0315] In addition, it should be noted that in this embodiment of the present application, Fig. 10 shows an implementation in which PPDUs sent by the first communication device can be aggregated. This implementation can be used in combination with the antenna selection solution shown in Fig. 4 or Fig. 5, or can be implemented independently. In this embodiment of the present application, the eleventh frame in step S601 can be an NDPA frame.

[0316] When this implementation is used in combination, the corresponding content of step S601 should be referred to the corresponding content of step S401, and the corresponding content of the eleventh frame should be referred to the corresponding content of the first frame. For information on the corresponding content of step S603, the corresponding content of step S403 should be referred to. The corresponding content of the antenna selection feedback result is given in the corresponding description of the second frame. When this implementation is used in combination, the number of NDPs shown in Fig. 4 or Fig. 5 may be equivalent to the number of the first information fields shown in Fig. 10. When this implementation is used in combination, the structure of the third PPDU should be referred to for a description of the structure of the first PPDU. In other words, the first PPDU may also include first information fields corresponding to a plurality of sets of transmit antennas.For example, the first PPDU includes a first information field corresponding to the first transmit antenna and additionally includes a first information field corresponding to the second transmit antenna. The first PPDU includes one preamble. In addition, the U-SIG in the preamble may be located in every first information field. The first identifier field may be carried in every first information field.

[0317] Based on the above content, Fig. 12 shows a schematic diagram of an example of signal interaction of a method for probing a channel of a receiving antenna according to an embodiment of the present application.

[0318] The interaction between the first communication device and the second communication device shown in Fig. 12 is used for presentation as an example. In this embodiment of the present application, the first communication device may also be referred to as an antenna selection transmitter, and the second communication device may also be referred to as an antenna selection transponder.

[0319] The first communication device shown in Fig. 12 may be the first communication device shown in Fig. 1, may be the AP or STA shown in Fig. 2, or may be the communication device shown in Fig. 3. The second communication device shown in Fig. 12 may be the second communication device shown in Fig. 1, may be the AP or STA shown in Fig. 2, or may be the communication device shown in Fig. 3. The first communication device and the second communication device in Fig. 12 may be simultaneously an AP, simultaneously an STA, or, respectively, an AP and an STA. In Fig. 12, an example is used for presentation in which the first communication device is an AP and the second communication device is an STA.

[0320] The solution provided in this embodiment of the present application is applicable to a procedure of sounding a receive antenna channel between an AP and one STA, or is applicable to a procedure of sounding a receive antenna channel between an AP and multiple STAs. Fig. 12 shows a schematic diagram of an example in which a procedure of sounding a receive antenna channel is performed between an AP and an STA (for example, STA 203 in Fig. 12).

[0321] It should be noted that the solution shown in Fig. 12 is used to select a receiving antenna in the first communication device. The solutions shown in Fig. 4 and Fig. 10 are used to select a transmitting antenna in the first communication device. The solution shown in Fig. 12 can be used in combination with the solution shown in Fig. 4 or Fig. 10, or can be implemented independently. The solution shown in Fig. 4 or Fig. 10 can also be implemented independently or can be used in combination with the solution shown in Fig. 12. When the solutions shown in Fig. 4 and Fig. 12 are used in combination, the first communication device can select a transmitting antenna in accordance with the solution shown in Fig. 4 and select a receiving antenna in accordance with the solution shown in Fig. 12. When the solutions shown in Fig. 10 and Fig. 12 are used in combination, the first communication device can select a transmitting antenna in accordance with the solution shown in Fig.10, and select the receiving antenna in accordance with the solution shown in Fig.12.

[0322] As shown in Fig. 12, the method includes the following steps.

[0323] S701: The first communication device transmits a fifth frame to the second communication device, wherein the fifth frame includes fourth indicator information, and the fourth indicator information instructs the second communication device to perform channel probing of the receiving antenna in the first communication device.

[0324] Accordingly, the second communication device receives the fifth frame from the first communication device.

[0325] In this embodiment of the present application, the fifth frame may have multiple implementations. For example, the fifth frame may be the second trigger frame, or the fifth frame may be an NDPA frame. The details are described below and are not described here.

[0326] S702: The second communication device transmits a second PPDU to the first communication device. The second communication device uses the second PPDU to perform channel sounding of the receiving antenna. The second PPDU includes a fifth identifier field, and the fifth identifier field indicates the identifier of the first set of receiving antennas.

[0327] Accordingly, the first communication device receives the second PPDU from the second communication device.

[0328] In a possible implementation, in step S702, the second communication device may transmit one or more PPDUs after the first communication device transmits the fifth frame and after a short inter-frame space (SIFS), and adjacent PPDUs may also be spaced by the SIFS. The second PPDU is one of the one or more PPDUs sent by the second communication device in step S702.

[0329] In a possible implementation, the second PPDU in step S702 may be a PPDU including a data field.

[0330] In another possible implementation, the second PPDU in step S702 may not include a data field. For example, the second PPDU is an NDP, which does not include a data field. Since the NDP does not include a data field, using the NDP as the second PPDU can reduce the overhead. In particular, in a large-scale antenna scenario, since there are a large number of antenna sets, there are also a large number of second PPDUs for receiving antenna channel sounding, and accordingly, the overhead for selecting a transmit antenna increases. However, in this solution, in which receiving antenna channel sounding is performed based on the NDP, the overhead in a large-scale antenna scenario can be further reduced.

[0331] In a possible implementation, the second communication device can transmit one or more PPDUs to the first communication device. The second PPDU is one of the one or more PPDUs. The PPDU in one or more PPDUs can include a fifth identifier field, and the fifth identifier field of the PPDU in the one or more PPDUs indicates the identifier of the set of receive antennas corresponding to the PPDU. For example, since the second PPDU is used to perform channel sounding of the receive antenna in the first set of receive antennas, the fifth identifier field in the second PPDU indicates the identifier of the first set of receive antennas. As another example, if another PPDU, different from the second PPDU in the one or more PPDUs, is a PPDU used to perform channel sounding of the receive antenna in the second set of receive antennas, the fifth identifier field in the PPDU indicates the identifier of the second set of receive antennas.

[0332] In this embodiment of the present application, the PPDU transmitted by the second communication device to the first communication device can also be considered as a sounding PPDU used to perform antenna channel sounding. In a possible implementation, step S703 is performed after step S702.

[0333] S703: The first communication device performs channel probing of the receiving antenna based on the second PPDU to obtain the second antenna selection feedback result.

[0334] In step S703, the first communication device may receive, based on different sets of receiving antennas, a plurality of PPDUs sent by the second communication device to perform channel sounding of the receiving antenna of the different sets of receiving antennas to obtain a feedback result of selecting the second antenna.

[0335] In this embodiment of the present application, the first communication device performing the sounding of the receiving antenna channel may be a device having the antenna selection capability (ASEL). The transmitting side with the antenna selection capability (e.g., the second communication device) may perform the sounding of the ASEL channel using the NDP sounding PPDU.

[0336] In step S703, the first communication device may perform receive antenna channel sounding based on the received one or more PPDUs to obtain one or more receive antenna channel sounding results. Furthermore, the first communication device may select a set of receive antennas based on the obtained receive antenna channel sounding results.

[0337] Furthermore, the first communication device may indicate the identifier of the selected set of receiving antennas to the second communication device. For example, in step S703, the first communication device may further add the second antenna selection feedback result to the sixth frame for transmission. The first communication device transmits the sixth frame. The sixth frame includes the second antenna selection feedback result. The second antenna selection feedback result includes a seventh identifier field. The seventh identifier field indicates the identifier of the first set of receiving antennas.

[0338] It should be noted that the seventh identifier field may contain the identifier of the set of receive antennas selected by the first communication device. For example, if the set of receive antennas selected by the first communication device is the first set of receive antennas, the seventh identifier field may indicate the identifier of the first set of receive antennas. In this embodiment of the present application, an example is used for presentation in which the set of receive antennas selected by the first communication device is the first set of receive antennas. During actual application, the first communication device may also select another set of receive antennas (in this case, the seventh identifier field should indicate another set of receive antennas). This case is not limited in this embodiment of the present application.

[0339] In this embodiment of the present application, the selected transmitting antenna of the first communication device may be the same as or different from the selected receiving antenna of the first communication device. In other words, the first set of transmitting antennas and the first set of receiving antennas may be the same set of antennas or may be different sets of antennas. This case is not limited in this embodiment of the present application.

[0340] Accordingly, the second communication device receives the sixth frame from the first communication device.

[0341] It should be noted that the first communication device may or may not transmit the sixth frame. S403 is optional. The first communication device performs channel probing of the receive antenna based on the second PPDU to obtain the second antenna selection feedback result and receives data from the second communication device based on the selected first set of receive antennas.

[0342] In a possible implementation, after step S702, the first communication device may perform sounding of the receive antenna channel based on the PPDUs from one or more second communication devices to obtain an antenna selection feedback result. In step S703, one second communication device is used as an example for description, and the solution of the other second communication device is similar to the solution of the second communication device described above. Details are not described again.

[0343] It should be noted that the antenna selection feedback results corresponding to different second communication devices may be different or may be the same. This case is not limited in this embodiment of the present application. Alternatively, it is obvious that the sets of receive antennas of the first communication device corresponding to different second communication devices may be different or may be the same. This case is not limited in this embodiment of the present application. For example, in Fig. 12, STA 203 (the second communication device) selects the first set of receive antennas, and another second communication device may select the first set of receive antennas or another set of receive antennas.

[0344] From the above, it is obvious that in this embodiment of the present application, since the fifth identifier field is added to the second PPDU, the first communication device can determine the identifier of the first set of receive antennas corresponding to the received second PPDU, and the first communication device can determine the channel sounding result of the receive antenna, obtained based on the NDP, as the channel sounding result of the receive antenna corresponding to the identifier of the first set of receive antennas. Accordingly, the first communication device can first determine the identifier of the set of receive antennas selected based on one or more channel sounding results of the receive antennas, and then receive data from the second communication device based on the set of receive antennas corresponding to the identifier of the selected set of receive antennas, so that the antenna selection can be performed based on the channel sounding result of the antenna in a large-scale antenna scenario.

[0345] With reference to Fig. 12, a further description will be given. In step S702, the second communication device may transmit to the first communication device one or more PPDUs used by the first communication device to perform channel sounding of the receive antenna. Each PPDU may correspond to a set of antennas from a group of receive antennas. The set of antennas of each group of receive antennas corresponds to one antenna set identifier (designated as an antenna set identifier (ID) in Fig. 12).

[0346] The antenna set identifiers shown in Fig. 12 are antenna set identifiers that are 0, 1, ... and R. R may be a positive integer. It should be noted that there is no necessary relationship between the number of transmit antenna sets and the number of receive antenna sets of the first communication device, and the number of transmit antenna sets and the number of receive antenna sets may be the same or may be different. The (R+1) receive antenna sets shown in Fig. 12 are just examples. The PPDUs shown in Fig. 12 are, respectively, PPDU (j0), PPDU (j1), ... and PPDU (j R). As shown in Fig. 12, the second communication device transmits a PPDU (j0) using the set of receive antennas whose antenna set ID is 0. The first communication device performs receive antenna channel sounding based on the PPDU (j0) to obtain a receive antenna channel sounding result corresponding to the set of receive antennas whose antenna set ID is 0. Similarly, the second communication device transmits a PPDU (j1) using the set of receive antennas whose antenna set ID is 1,..., and the second communication device transmits a PPDU (j R), using a set of receiving antennas whose antenna set ID is R. The first communication device obtains a result of the receiving antenna channel sounding corresponding to the set of receiving antennas whose antenna set ID is 1,..., and a result of the receiving antenna channel sounding corresponding to the set of receiving antennas whose antenna set ID is R. In addition, the first communication device may first select a set of receiving antennas of the first communication device based on R results of the receiving antenna channel sounding, for example, select a first set of receiving antennas, and then receive data from the second communication device using the first set of receiving antennas. In addition, the first communication device may further indicate to the second communication device the selected first set of receiving antennas.

[0347] The arrangement of antenna set identifiers in Fig. 12 is just an example. During actual application, the antenna set identifiers of successive PPDUs received by the first communication device may be arranged randomly, for example, non-sequentially or not in ascending order. For example, the second communication device may sequentially receive PPDU (j1) from the second communication device using the transmit antenna set whose antenna set ID is 1, receive PPDU (j R ) from the second communication device, using the transmit antenna set whose antenna set ID is R, receive PPDU (j0) from the second communication device, using the transmit antenna set whose antenna set ID is 0, and so on.

[0348] The following describes the relevant contents of the identifiers of the set of receiving antennas mentioned in this embodiment of the present application.

[0349] In a possible implementation, the first communication device includes k2 sets of receive antennas. k2 is a positive integer. R in Fig. 12 may be a positive integer not greater than k2. R may be equal to k2 or may be less than k2. The sets of k2 receive antennas are in one-to-one correspondence with the identifiers of the sets of k2 receive antennas. In other words, one of the k2 sets of receive antennas corresponds to one of the identifiers of the k2 sets of receive antennas, and one of the identifiers of the k2 sets of receive antennas corresponds to one of the k2 sets of receive antennas. The identifiers of two sets of receive antennas corresponding to any two sets of receive antennas may be different. The two sets of receive antennas corresponding to the identifiers of any two sets of receive antennas may be different. The first set of receive antennas is one of the k2 sets of receive antennas. An example using the first set of receive antennas is described below.

[0350] There are many implementations of receiver antenna set identifiers. Descriptions are provided individually as follows.

[0351] Implementation c1

[0352] In a possible implementation, the identifier of the first set of receive antennas may be a sequence number of the second PPDU corresponding to the first set of receive antennas.

[0353] In implementation c1, the fifth identifier field may indicate the rank of the second PPDU in the R PPDUs sent by the second communication device. When the PPDU transmitted by the second communication device in step S702 is an NDP, it is also obvious that the fifth identifier field may indicate the rank of the current NDP in the R NDPs sent by the second communication device. Thus, the first communication device can determine the correspondence between the second PPDU and the antenna selection feedback result of the receiving antenna based on the sequence number corresponding to the second PPDU indicated in the fifth identifier field.In this way, the first communication device may first determine an identifier of a set of receiving antennas selected based on one or more results of the channel sounding of the receiving antenna, and then receive data from the second communication device based on the set of receiving antennas corresponding to the identifier of the selected set of receiving antennas, so that the antenna selection can be performed based on the result of the channel sounding of the antenna in a large-scale antenna scenario.

[0354] Implementation c2

[0355] In another possible implementation, the identifier of the first set of receive antennas may be the group identifier of the first set of receive antennas. For the corresponding content of the group identifier of the first set of receive antennas, reference should be made to the corresponding content of the group identifier of the first set of transmit antennas. For implementation c2, reference should be made to implementation a2.

[0356] The receive antenna set identifier may further include the following possible implementations:

[0357] Implementation c2-1

[0358] The first communication device and the second communication device can perform negotiation. The first communication device can notify the second communication device of the total number of sets of receiving antennas supported by the first communication device through the negotiation. For example, the first communication device transmits the tenth frame to the second communication device. The tenth frame includes the eighth pointer information. The eighth pointer information indicates the total number of sets of receiving antennas supported by the first communication device. The tenth frame can be an MPDU. Thus, the second communication device can estimate the overhead and the duration of the receiving antenna selection procedure based on the eighth pointer information; and the second communication device can further determine, based on the total number of sets of receiving antennas supported by the first communication device, whether to establish an association relationship using the first communication device.

[0359] For the implementation of c2-1, please refer to the implementation of a2-1, and the details are not described here again.

[0360] Implementation c2-2

[0361] In this embodiment of the present application, the correspondence between the set of receive antennas and the group identifier in the first communication device may be predetermined (for example, may be specified in a standard). The correspondence may be predetermined in the first communication device or may be sent by another communication device to the first communication device. Thus, the first communication device can learn the identifier of the set of receive antennas of each set of receive antennas so that the identifier of the set of receive antennas is carried when sending PPDUs.

[0362] For the implementation of c2-2, please refer to the implementation of a2-2, and the details are not described here again.

[0363] Implementation c2-3

[0364] The first communication device and the second communication device agree on determining a group identifier of the first set of receiving antennas.

[0365] The first communication device and the second communication device can perform negotiation. The second communication device learns, through negotiation, the set of receive antennas supported by the first communication device; and after the negotiation, the first communication device and the second communication device establish a group identifier for the set of receive antennas supported by the first communication device. For example, the first communication device transmits the eighth frame to the second communication device. The eighth frame can be an MPDU. The second communication device receives the eighth frame. The eighth frame includes an eighth identifier field. The eighth identifier field indicates the identifier of at least one set of receive antennas supported by the first communication device. The identifier of at least one set of receive antennas includes the identifier of the first set of receive antennas.

[0366] Thus, the second communication device can learn the receive antenna set identifier of each receive antenna set, so that the receive antenna set identifier is carried over when transmitting. Furthermore, it is obvious that the second communication device can, through negotiation, obtain more information related to the antenna set and can subsequently obtain more information related to the communication channel, thereby further providing assistance for other subsequent procedures.

[0367] For the implementation of c2-3, please refer to the implementation of a2-3, and the details are not described here again.

[0368] It should be noted that implementation c1 and implementation c2 can be implemented separately or combined. For example, the identifier of the first set of receive antennas can include the sequence number of the second PPDU corresponding to the first set of receive antennas and the group identifier of the first set of receive antennas. This allows for more precise identification of the first set of receive antennas and increased solution flexibility.

[0369] In this embodiment of the present application, the identifier of the first set of receive antennas may be designated by one or more symbols or may be indicated by one or more bits, for example, may be indicated by one or more bits corresponding to binary bits. The information carried in the fifth identifier field may be all or some of the bits corresponding to the identifier of the first set of receive antennas. This implementation is similar to the corresponding content of the first set of transmit antennas. For details, please refer to the corresponding content of implementation b1 and implementation b2 of the first set of transmit antennas. The details are not described here again.

[0370] Based on the above content, Fig. 13 is a schematic diagram showing an example of signaling interaction of the antenna channel sounding method according to an embodiment of the present application. Steps S801, S802, and S803 are added to Fig. 13 based on Fig. 12. Since the fifth frame in step S701 shown in Fig. 12 may be an NDPA frame or may be the second trigger frame, step S701 may include two implementations: step S801 and step S803. After step S801 or step S803, the second communication device may perform step S702, and the first communication device may perform step S703. Below, the frame in this embodiment of the present application is further described with reference to the schematic diagram of signaling interaction shown in Fig. 13.

[0371] As shown in Fig. 13, the method includes the following steps.

[0372] S801: The first communication device transmits the second trigger frame.

[0373] The second trigger frame can be used to notify the second communication device that receive antenna selection needs to be performed.

[0374] S802: The second communication device transmits the seventh frame. The seventh frame includes the sixth pointer information. The sixth pointer information is used to request channel probing of the receiving antenna.

[0375] Accordingly, the first communication device receives the seventh frame.

[0376] In this embodiment of the present application, the second communication device may transmit the seventh frame based on the start of the second trigger frame in step S801, or may transmit the seventh frame independently. This case is not limited in this embodiment of the present application.

[0377] The related frame structures based on Fig.13 and Fig.12 are described below.

[0378] In a possible implementation, in this embodiment of the present application, the fifth frame in step S701 is the second trigger frame in step S801. The second trigger frame may further include fourth indicator information. The fourth indicator information may be used to notify the second communication device that it is necessary to select a transmit antenna. Alternatively, the fourth indicator information indicates that the second trigger frame is an option for selecting a receive antenna. The fifth frame may further include a number of NDPs and / or a sixth identifier field. The sixth identifier field indicates the identifier of the first set of receive antennas.

[0379] Fig. 14A and Fig. 14B show a schematic diagram of an example of the structure of the second trigger frame. In another possible implementation, the corresponding information on the selection of the receive antenna, such as the number of NDPs and / or the sixth identifier field, may be carried in some or all bits of at least one of the following contents: a reserved bit of the general information field, a reserved bit of the user information list field, trigger-dependent general information, or trigger-dependent user information.

[0380] As shown in Fig. 14A and Fig. 14B, in this embodiment of the present application, the existing trigger frame structure can be used for the second trigger frame, and the existing field of the second trigger frame carries content related to the selection of the receiving antenna. As shown in Fig. 14A and Fig. 14B, the second trigger frame can include a general information field and a user list and information field.

[0381] The general information field may include at least one of the following: trigger type, uplink (UL) length, more trigger frames, carrier sense required, uplink (HE) bandwidth, guard interval (GI) + EHT-LTF Type, EHT-LTF Multi-User Multiple-Input Multiple-Output (MU-MIMO), Number of EHT-LTF Symbols And Midamble Periodicity, uplink space-time block coding (UL STBC), low-density parity-check code (Low-Density Parity-Check Code, LDPC), LDPC Extra Symbol Segment, AP TX Power,Pre-FEC Padding Factor, PE Disambiguity, UL Spatial Reuse, Doppler, UL HE-SIG-A2 Reserved, Reserved, and trigger dependent common Info.

[0382] The uplink HE-SIG-A2 Reserved signaling field may include the HE / EHT indicator, the user-specific field presence indicator, and another UL HE-SIG-A2 Reserved signaling field.

[0383] The user information list field may include one or more pieces of user information, such as user information 1, user information 2, ..., and user information M, as shown in the figure. One or more pieces of user information may be a special user information field, or one or more pieces of user information may be an EHT variant user information field.

[0384] The dedicated user information field may include: an association identifier (AID12) (=2007), a physical version ID, an uplink EHT bandwidth extension (UL EHT BW Extension), an uplink EHT spatial reuse 1 (UL EHT Spatial Reuse 1), an uplink EHT spatial reuse 2 (UL EHT Spatial Reuse 2), a universal signaling field disregard and validate (U-SIG Disregard And Validate), a reserve field, and trigger-dependent user information (trigger-dependent user Info). In this embodiment of the present application, the information may also be abbreviated as Info and indicates information.

[0385] The EHT User Info 2-M field may include the following contents: Association Identifier (AID12), Resource Block Allocation (RU Allocation), UL Forward Error Correction Coding Type (UL EHT-modulation and coding scheme), Reserved, Spatial Stream Initial Value, Number of Spatial Streams, UL Target Received Signal Strength Indicator (UL Target Received Signal Strength Indicator), Primary / Secondary Channel Indicator at 160 MHz (PS160), and Trigger Dependent User Info.

[0386] Table 2 shows a schematic diagram of an example of the definition of the trigger type values ​​of the second trigger frame shown in Fig. 14A and Fig. 14B. From Table 2, it can be seen that in the current standard, 8 to 15 trigger types of the second trigger frame are reserved values. When the second trigger frame is selected as the fifth frame, the trigger type value of the second trigger frame can be selected from 8 to 15, so that the trigger type value of the second trigger frame can indicate that the second trigger frame is used to select the receiving antenna. The trigger type value of the second trigger frame can be used as a possible implementation of the fourth indicator information.

[0387] Table 2. Schematic representation of the definitions of the trigger type values ​​of the second trigger frame

[0388] Trigger type value (trigger type subfield value) Trigger Type Value Definitions (Trigger Frame Variant) 0 Basic 1 Beamforming Report Polling (BFRP) 2 Multi-user block acknowledge request (MU-BAR) 3 Multi-user request to send (MU-RTS) 4 Buffer status report poll (BSRP) 5 Groupcast with Retries (GCR) 6 Bandwidth query report poll (BQRP) 7 NDP Feedback Report Poll (NFRP) 8-15 Reserved

[0389] In step S802, the seventh frame may be referred to as a receive antenna selection sounding request. The seventh frame may further include a number of PPDUs that the second communication device requests to be sent. Thus, the first communication device may determine, based on the number of PPDUs carried in the seventh frame, the number of PPDUs that the second communication device needs to further send, so that the number of PPDUs that the second communication device determines to be subsequently transmitted by the first communication device meets the requirements of the second communication device as closely as possible. The number of PPDUs sent by the second communication device may be the same as or different from the number of PPDUs requested in the seventh frame.

[0390] The seventh frame can be carried in an MPDU in which the MAC frame header carries a High Throughput Control (HTC) field. The frame structure shown in Fig. 6 can be used as the frame structure of the seventh frame. The embodiment related to the seventh frame is a high-efficiency embodiment, or it can be regarded as the sixth indicator information being carried in the high-efficiency embodiment field of the seventh frame. The sixth indicator information is carried in at least one of a control identifier field, an antenna selection command field, or an antenna selection data field in the A-control subfield. In this embodiment of the present application, the control identifier value of the control identifier field, which is not used in the standard, can be used to indicate the receiving antenna selection procedure in this embodiment of the present application.For example, the value of the control identifier of the control identifier field may be one of 9 or 11-14. In this case, the length of the control information field can be a maximum of 26 bits. When the seventh frame is an MPDU, the corresponding description and useful effect are given in the corresponding description of Fig. 6. Details are not described here again.

[0391] In step S803, the first communication device may transmit an NDPA frame based on the seventh frame sent by the second communication device, or may independently transmit an NDPA frame. This case is not limited in this embodiment of the present application. In another possible implementation, the fifth frame in step S701 may be an NDPA frame. In this case, the NDPA frame may be a frame including fourth indicator information indicating that the second communication device should perform channel sounding of the receiving antenna.

[0392] The fifth frame (e.g., NDPA frame) may optionally include the number of NDPs and / or a sixth identifier field. The sixth identifier field indicates the identifier of the first set of receive antennas.

[0393] In a possible implementation, when the NDPA frame includes a sixth identifier field, the sixth identifier field may include all the bits corresponding to the identifier of the first set of receive antennas. Therefore, the fifth identifier field in the second PPDU subsequently sent by the second communication device may carry some bits corresponding to the identifier of the first set of receive antennas, so that the number of bits occupied by the fifth identifier field in the second PPDU can be reduced, and may carry some bits corresponding to the identifier of the first set of receive antennas. The first communication device can determine all the bits of the identifier of the first set of receive antennas corresponding to the second PPDU based on the sixth identifier field and the fifth identifier field.

[0394] Fig. 15 is a schematic diagram of an example of the structure of the fifth frame, when the fifth frame is an NDPA frame. The sixth identifier field and the number of NDPs are not necessarily included in the NDPA frame. In Fig. 15, an example is used for the representation in which the fifth frame includes the sixth identifier field, a number of NDPs, and the fourth pointer information. The difference between the NDPA frame structure shown in Fig. 15 and the NDPA frame structure shown in Fig. 7 is that in Fig. 15, an example is used for the representation in which the identifier of the set of receiving antennas is included, and an example is used for the representation in which the association identifier field is 2043. For further details and beneficial effects, please refer to the description of Fig. 7.

[0395] Similarly, in this embodiment of the present application, a specific association identifier of the station information field may indicate that the information in the station information field is information related to antenna selection. For example, at least one of the fourth indicator information, the number of NDPs, or the sixth identifier field may be carried in at least one station information field that relates to the fifth frame and that includes the fifth indicator information. The fifth indicator information indicates that the station information field includes information related to antenna selection. Thus, when the fifth indicator information is identified, the second communication device can determine that the station information field carrying the fifth indicator information carries information related to antenna selection, and then obtain the information related to antenna selection from the station information field.The fifth indicator information may distinguish a station information field carrying information related to antenna selection from a station information field corresponding to another legacy station, so that in a solution in which the station information field carries information related to antenna selection, the station information field corresponding to the legacy station is not affected, and compatibility with the existing standard is achieved.

[0396] Similar to Fig. 7, the fifth pointer information can be carried in the association identifier field of the station information field. The fifth pointer information includes one of the digits 2008-2043 or 2046. In this way, the second communication device can determine, based on the association identifier field, whether the station information field carries information related to antenna selection or station information corresponding to another second communication device. Obviously, this solution allows for higher compatibility with conventional technology. The fourth pointer information can also be referred to as an antenna selection type, NDPA antenna selection option pointer information, or an NDPA frame option subtype. The fourth pointer information further indicates that the NDPA frame option is an antenna selection option.

[0397] The NDPA frame with the HT management field is no longer supported in the 802.11ax-802.11be standards. In this embodiment of the present application, the relevant information related to antenna selection is carried in the station information field, so that the information necessary for antenna selection can be specified. In addition, the association identifier in the association identifier field of the station information field is a special association identifier, and a plurality of second communication devices can read the content of the station information field.

[0398] In step S702, the second PPDU transmitted by the second communication device may not include a data field, such as NDP, or may include a data field. The descriptions are given separately as follows.

[0399] When the second PPDU does not include a data field, the structure of the second PPDU may be the NDP structure shown in Fig. 8a or Fig. 8b. When the second PPDU is the NDP shown in Fig. 8a or Fig. 8b, the fifth identifier field is located in the preamble of the second PPDU. For example, the fifth identifier field may include some or all of the bits in the U-SIG and / or some or all of the bits in the EHT-SIG. The corresponding contents are given in the descriptions of Fig. 8a and Fig. 8b. The details are not described again.

[0400] In another possible implementation, when the second PPDU does not include a data field, the structure of the second PPDU may be shown in the schematic diagram of the NDP structure shown in Fig. 16a or Fig. 16b. Fig. 16a and Fig. 16b show a schematic diagram of the structures of two types of second PPDUs, in which the second PPDUs are NDPs. Compared with Fig. 8a, the EHT-SIG field in Fig. 16a is omitted. For other fields, refer to the corresponding description in Fig. 8a. Compared with Fig. 8b, the NG-SIG field in Fig. 16b is omitted. For other fields, refer to the corresponding description in Fig. 8b. When the second PPDU is the NDP shown in Fig. 16a or Fig. 16b, the fifth identifier field is located in the preamble of the second PPDU. For example, the fifth identifier field may include some or all of the U-SIG bits.For example, one or more bits B20-B24 of the first U-SIG symbol and B25 of the first U-SIG field symbol may be used as the fifth identifier field.

[0401] When the second PPDU includes a data field, the structure of the second PPDU can be shown in the schematic diagram of the frame structure in Fig. 8c. When the second PPDU is a frame shown in Fig. 8c, the fifth identifier field is located in the preamble of the second PPDU. For example, the fifth identifier field may include some or all bits of at least one of the U-SIG, EHT-SIG, or data field. The corresponding content is given in the descriptions of Fig. 8a and Fig. 8b. The details are not described again.

[0402] In another possible implementation, when the second PPDU includes a data field, the structure of the second PPDU can be shown in the schematic diagram of the frame structure in Fig. 16c. Fig. 16c shows a schematic diagram of an example of the structure of the second PPDU including a data field. Compared with Fig. 8c, the NG-SIG field is missing in Fig. 16c. For other fields, refer to the corresponding description in Fig. 8c. When the second PPDU is the frame structure shown in Fig. 16c, the fifth identifier field is located in the preamble of the second PPDU. For example, the fifth identifier field may include some or all of the bits in at least one of the U-SIG or the data field. For the corresponding content, see the above description. The details are not described again.

[0403] In step S703, the sixth frame may be a beamforming report frame, and the frame structure may be the frame structure shown in Fig. 9. For the relevant descriptions, refer to the relevant descriptions shown in Fig. 9. Next, a description of the sixth frame is given with reference to Fig. 9.

[0404] The sixth frame may include a MIMO control field. The seventh identifier field may include some or all of the bits of the MIMO control field. The seventh identifier field includes all bits corresponding to the identifier of the first set of receive antennas. Thus, the second communication device can determine, based on the seventh identifier field in the sixth frame, that the set of receive antennas selected by the first communication device is the first set of receive antennas.

[0405] In a possible implementation, the seventh identifier field may include two parts: an antenna set identifier field and a probing PPDU sequence number field. The antenna set identifier field may contain the group identifier of the first set of receiving antennas, and the probing PPDU sequence number field may contain the sequence number of the second PPDU corresponding to the first set of receiving antennas.

[0406] In another possible implementation, the sixth frame may further include an antenna selection error feedback field. In yet another possible implementation, the sixth frame may further include at least one of a compressed beamforming report, a multi-user beamforming report, and a channel quality status report. For example, the channel quality status report may include, for example, at least one of channel state information (CSI) or channel quality information (CQI QI) corresponding to the PPDU.

[0407] One or more of the compressed beamforming report, the multi-user beamforming report, and the channel quality status report may be carried in a field other than the MIMO control field in the sixth frame. Of course, at least one of the antenna set identifier field and the sounding PPDU sequence number field, which are included in the seventh identifier field, may alternatively be set in another field. For example, the sounding PPDU sequence number field may be located in the A-control subfield. For information about other contents of the sixth frame, please refer to the corresponding description of Fig. 9. The details are not described here again.

[0408] From the above content, it is clear that in this embodiment of the present application, for example, when the NDPA frame does not support the high-throughput control field, an embodiment of the antenna selection procedure for the receive antenna is provided based on NDPA (fifth frame) + NDP (PPDU) + feedback (sixth frame). The antenna selection procedure can correspond to the current channel sounding procedure, the devices on the receiving and transmitting sides are slightly modified, and the implementation is simple.

[0409] Based on the above content, Fig. 17 is a schematic diagram of an example of signal interaction of an antenna channel sounding method according to an embodiment of the present application.

[0410] In Fig. 17, the interaction between the first communication device and the second communication device is used for illustration purposes. In this embodiment of the present application, the first communication device may also be referred to as an antenna selection transmitter, and the second communication device may also be referred to as an antenna selection transponder.

[0411] The first communication device shown in Fig. 17 may be the first communication device shown in Fig. 1, may be the AP or STA shown in Fig. 2, or may be the communication device shown in Fig. 3. The second communication device shown in Fig. 17 may be the second communication device shown in Fig. 1, may be the AP or STA shown in Fig. 2, or may be the communication device shown in Fig. 3. The first communication device and the second communication device in Fig. 17 may be simultaneously an AP, simultaneously an STA, or, respectively, an AP and an STA. In Fig. 17, an example is used for presentation in which the first communication device is an AP and the second communication device is an STA.

[0412] The solution provided in this embodiment of the present application is applicable to a procedure of sounding a receive antenna channel between an AP and one STA, or is applicable to a procedure of sounding a receive antenna channel between an AP and multiple STAs. Fig. 17 is a schematic diagram of an example in which a procedure of sounding a receive antenna channel is performed between an AP and multiple STAs (for example, STA 203, STA 204, and STA 205 in Fig. 17).

[0413] It should be noted that the solution shown in Fig. 17 is used to select a receiving antenna in the first communication device. The solutions shown in Fig. 4 and Fig. 10 are used to select a transmitting antenna in the first communication device. The solution shown in Fig. 17 can be used in combination with the solutions shown in Fig. 4 or Fig. 10, or can be implemented independently. The solution shown in Fig. 4 or Fig. 10 can also be implemented independently or can be used in combination with the solution in Fig. 17. When the solutions shown in Fig. 4 and Fig. 17 are used in combination, the first communication device can select a transmitting antenna in accordance with the solution shown in Fig. 4 and select a receiving antenna in accordance with the solution shown in Fig. 17. When the solutions shown in Fig. 10 and Fig. 17 are used in combination, the first communication device can select a transmitting antenna in accordance with the solution shown in Fig.10, and select the receiving antenna in accordance with the solution shown in Fig. 17.

[0414] As shown in Fig. 17, the method includes the following steps:

[0415] S901: The first communication device transmits a twelfth frame to the second communication device, where the twelfth frame includes fourth pointer information, and the fourth pointer information instructs the second communication device to perform channel probing of the receiving antenna.

[0416] Accordingly, the second communication device receives the twelfth frame from the first communication device.

[0417] S902: The second communication device transmits the fourth PPDU to the first communication device. The fourth PPDU is used to probe the receiving antenna channel.

[0418] Accordingly, the first communication device receives the fourth PPDU from the second communication device.

[0419] The fourth PPDU may include M2 ​​second information fields corresponding to M2 sets of receive antennas. M2 is an integer greater than 1. The second information field is used to perform channel sounding of the receive antenna.

[0420] S903: The first communication device performs channel probing of the receiving antenna based on the second PPDU to obtain the second antenna selection feedback result.

[0421] In addition, in step S903, the first communication device may further transmit back the feedback result of selecting the second antenna to the second communication device.

[0422] It is evident from the solution that in this embodiment of the present application, the second communication device can aggregate PPDUs corresponding to M2 sets of receiving antennas , which need to be transmitted in step S902, into one PPDU in order to reduce the amount of overhead data, improve the efficiency of antenna selection, and increase the system throughput.

[0423] Figures 18 and 19, respectively, schematically show examples of frame structures of two types of fourth PPDUs. Compared with Figure 18, the frame structure in Figure 19 does not include the EHT-SIG field.

[0424] As shown in Fig. 18 and Fig. 19, the fourth PPDU may include M2 ​​second information fields corresponding to M2 sets of receive antennas. M2 may be an integer greater than 1. The second information field is used to perform channel sounding of the receive antenna.

[0425] The second information field includes at least one of a short EHT training field, a long EHT training field, and a packet extension field. Any two second information fields use different sets of receive antennas. For example, the three sets of receive antennas shown in Fig. 18 are, respectively, the second information field corresponding to the set of receive antennas whose antenna set ID is 0, the second information field corresponding to the set of receive antennas whose antenna set ID is 1, ..., and the second information field corresponding to the set of receive antennas whose antenna set ID is M2.

[0426] As shown in Fig. 18, the fourth PPDU may further include a preamble. The preamble includes at least one of the following fields: L-STF, L-LTF, L-SIG, RL-SIG, U-SIG, or EHT-SIG. As shown in Fig. 19, the fourth PPDU may further include a preamble. The preamble includes at least one of the following fields: L-STF, L-LTF, L-SIG, RL-SIG, or U-SIG. The corresponding description of the preamble is given in the corresponding description of Fig. 16a. The details are not described here again.

[0427] In Fig. 18 and Fig. 19, it can be seen that in step S902, M2PPDUs corresponding to M2 sets of receiving antennas that initially need to be transmitted are aggregated into one fourth PPDU, so that (M2–1) preambles can be shortened.

[0428] In addition, it is shown in Fig. 18 that every second information field may include one packet extension field, for example, packet extension 0 in the second information field corresponding to the antenna set ID=0 shown in Fig. 18, packet extension 1 in the second information field corresponding to the antenna set ID=1 shown in Fig. 18, ..., and packet extension M2 in the second information field corresponding to the antenna set ID=M2 shown in Fig. 18. The duration of any two data extensions in the packet extensions (from packet extension 0 to packet extension (M2-1)) except for the last M2 extension of the packet may be the same. The duration of these packet extension fields may be used to provide more processing time for the second communication device. In addition, the first communication device can provide time for switching the antenna.Additionally, the duration can be set to a shorter value, which is enough for the first communication device to switch the antenna.

[0429] In a possible implementation, the duration of the packet extension fields in at least two second information fields of the M2 second information fields may be different. For example, the duration of the M2 packet extension may differ from the duration of the 1-packet extension. The duration of the M2-packet extension can be set to a slightly longer value. The duration of packet extension 1 can be set to a slightly shorter value, and it is sufficient for the first communication device to switch the antenna. In addition, in this implementation, the duration of any two data extensions in packet extensions (from packet extension 0 to packet extension (M2–1)) except for the last extension of the M2 packet can be the same or different.

[0430] In another possible implementation, the length of the packet extension fields in any two of the M2 second information fields is the same. This can improve the compatibility of the reception procedure.

[0431] Compared with the solution in which the second communication device transmits PPDUs corresponding to M2 receiving antennas, in the solution shown in Fig. 18, it is only necessary to transmit one fourth PPDU to achieve the purpose of transmitting M2 information groups used to perform channel sounding of the receiving antenna. In this solution, the (M2-1) preamble groups (from L-STF to EHT-SIG) and the short inter-frame space SIFS can be reduced. When the time of any two of the 0 packet extension and the (M2-1) packet extension are the same, and the duration of the 0 packet extension is shorter than the duration of the M2 packet extension, the time difference between the M2 packet extension and the 0 packet extension can be further reduced.

[0432] For example, the preamble (L-STF for EHT-SIG) in the fourth PPDU lasts for a total of 36 microseconds, the duration of the M2 extension packet is 16 microseconds, and the SIFS lasts for 16 microseconds. If the time of any of the extension 0 packet to the extension (M2-1) packet is 4 microseconds, and M2=64, compared with transmitting PPDUs corresponding to M2 receiving antennas (the PPDU includes a preamble and one second information field, and the data extension field included in the second information field is 16 microseconds), in this case, 36×(64-1)+16×(64-1)+(16-4)×(64-1)=4032 microseconds can be reduced by transmitting the fourth PPDU.

[0433] It should be noted that Fig. 18 is just an example of the frame structure of a possible fourth PPDU. In this example, the EHT-SIG is transmitted once. In another possible implementation, the EHT-SIG may appear in groups. For example, every second information field includes one EHT-SIG. In addition, in Fig. 17, an example is used for presentation in which the second communication device transmits one fourth PPDU. During actual application, in step S902, the second communication device may transmit one or more fourth PPDUs, and the number of second information fields included in the fourth PPDUs may be the same or may be different.

[0434] In addition, it should be noted that in this embodiment of the present application, Fig. 17 shows an implementation in which PPDUs sent by the second communication device can be aggregated. This implementation can be used in combination with the antenna selection solution shown in Fig. 12 or Fig. 13, or can be implemented independently. In this embodiment of the present application, the twelfth frame in step S901 can be an NDPA frame.

[0435] When this implementation is used in combination, the corresponding content of step S901 should be referred to the corresponding content of step S701, and the corresponding content of the twelfth frame should be referred to the corresponding content of the fifth frame. For the corresponding content of step S903, reference should be made to the corresponding content of step S703. The corresponding content of the antenna selection feedback result is given in the corresponding description of the sixth frame. When this implementation is used in combination, the number of NDPs shown in Fig. 12 or Fig. 13 may be equivalent to the number of second information fields shown in Fig. 17. When this implementation is used in combination, the structure of the second PPDU should be referred to the structure of the fourth PPDU. In other words, the second PPDU may also include second information fields corresponding to a plurality of sets of receiving antennas.For example, the second PPDU includes a second information field corresponding to the first receive antenna and further includes a second information field corresponding to the second receive antenna. The first PPDU includes one preamble. Additionally, the U-SIG in the preamble may be located in every other information field. The fifth identifier field may be carried in every other information field.

[0436] It is understood that, to implement the functions in the previous embodiments, the communication device includes corresponding hardware structures and / or software modules for performing the functions. It should be obvious to those skilled in the art that, in the present application, the blocks and steps of the method in the examples described with reference to the embodiments disclosed in this application can be implemented using hardware or a combination of hardware and computer software. Whether the function is performed using hardware or hardware under the control of computer software depends on the specific application scenarios and design limitations of the technical solutions.

[0437] Each of Fig.20, Fig.21 and Fig.22 show a schematic diagram of the structure of a possible communication device according to an embodiment of the present application. The communication devices can be configured to implement the functions of the first communication device in the above embodiments of the method and, thus, can also implement the beneficial effect of the above embodiments of the method. These communication devices can alternatively be configured to implement the functions of the second communication device in the above embodiments of the method and, thus, can also implement the beneficial effect of the above embodiments of the method. In these embodiments of the present application, the communication device may be the transmitting device or the first communication device shown in Fig.1, Fig.2, Fig.3, Fig.4, Fig.5, Fig.10, Fig.12, Fig.13 or Fig.17, or may be a module (for example, a microcircuit) used in the transmitting device or the first communication device. In these embodiments of the present application, the communication device may be the receiving device or the second communication device shown in Fig. 1, Fig. 2, Fig. 3, Fig. 4, Fig. 5, Fig. 10, Fig. 12, Fig. 13 or Fig. 17, or may be a module (for example, a microcircuit) used in the receiving device or the second communication device.

[0438] As shown in Fig. 20, the communication device 1300 includes a processing unit 1310 and a transceiver unit 1320. The communication device 1300 is configured to implement the function of the first communication device in the embodiment of the method shown in Fig. 4, Fig. 5, Fig. 10, Fig. 12, Fig. 13 or Fig. 17.

[0439] When the communication device 1300 is configured to implement the function of the first communication device in the embodiment of the method shown in Fig. 4 or Fig. 5, the processing unit 1310 is configured to: send a first frame to the second communication device and send a first PPDU to the second communication device using the transceiver unit 1320. The first frame includes first indicator information. The first indicator information indicates the second communication device to perform channel sounding of the transmit antenna. The first PPDU is an NDP. The first PPDU is used by the second communication device to perform channel sounding of the transmit antenna. The first PPDU includes a first identifier field. The first identifier field indicates the identifier of the first set of transmit antennas.

[0440] When the communication device 1300 is configured to implement the function of the first communication device in the embodiment of the method shown in Fig. 4 or Fig. 5, the processing unit 1310 is further configured to receive a second frame from the second communication device using the transceiver unit 1320. The second frame includes a feedback result of selecting the first antenna. The feedback result of selecting the first antenna includes a third identifier field. The third identifier field indicates the identifier of the first set of transmit antennas.

[0441] When the communication device 1300 is configured to implement the function of the first communication device in the embodiment of the method shown in Fig. 4 or Fig. 5, the processing unit 1310 is configured to send a fourth frame to the second communication device using the transceiver unit 1320. The fourth frame includes a fourth identifier field. The fourth identifier field indicates the identifier of at least one set of transmit antennas supported by the first communication device. The identifier of at least one set of transmit antennas includes the identifier of the first set of transmit antennas.

[0442] When the communication device 1300 is configured to implement the function of the first communication device in the embodiment of the method shown in Fig. 4 or Fig. 5, the processing unit 1310 is configured to send a ninth frame to the second communication device using the transceiver unit 1320. The ninth frame includes seventh indicator information. The seventh indicator information indicates the total number of sets of transmit antennas supported by the first communication device.

[0443] When the communication device 1300 is configured to implement the function of the first communication device in the embodiment of the method shown in Fig. 10, the processing unit 1310 is configured to send an eleventh frame to the second communication device using the transceiver unit 1320. The eleventh frame includes first indicator information. The first indicator information indicates the second communication device to perform channel sounding of the transmit antenna. The first communication device transmits a third PPDU to the second communication device. The third PPDU is used by the second communication device to perform channel sounding of the transmit antenna. The third PPDU includes M1 first information fields corresponding to M1 sets of transmit antennas. M1 is an integer greater than 1. The first information field is used to perform channel sounding of the transmit antenna.The first information field includes at least one of a short EHT training field, a long EHT training field, and a packet extension field.

[0444] When the communication device 1300 is configured to implement the function of the first communication device in the embodiment of the method shown in Fig. 12 or Fig. 13, the processing unit 1310 is configured to: send a fifth frame to the second communication device and receive a second PPDU from the second communication device using the transceiver unit 1320. The fifth frame includes fourth indicator information. The fourth indicator information indicates the need to perform channel sounding of the receive antenna in the first communication device. The second PPDU for the first communication device is an NDP. The second PPDU is used by the first communication device to perform channel sounding of the receive antenna. The second PPDU includes a fifth identifier field. The fifth identifier field indicates the identifier of the first set of receive antennas.

[0445] When the communication device 1300 is configured to implement the function of the first communication device in the embodiment of the method shown in Fig. 17, the processing unit 1310 is configured to: send the twelfth frame to the second communication device and receive the fourth PPDU from the second communication device using the transceiver unit 1320. The twelfth frame includes fourth indicator information. The fourth indicator information indicates the need to perform channel sounding of the receive antenna in the first communication device. The fourth PPDU is used by the second communication device to perform channel sounding of the receive antenna. The fourth PPDU includes M2 second information fields corresponding to M2 sets of receive antennas. M2 is an integer greater than 1. The second information field is used to perform channel sounding of the receive antenna.The second information field includes at least one of a short EHT training field, a long EHT training field, and a packet extension field.

[0446] As shown in Fig. 20, the communication device 1300 includes a processing unit 1310 and a transceiver unit 1320. The communication device 1300 is configured to implement the function of the second communication device in the embodiment of the method shown in Fig. 4, Fig. 5, Fig. 10, Fig. 12, Fig. 13 or Fig. 17.

[0447] When the communication device 1300 is configured to implement the function of the second communication device in the embodiment of the method shown in Fig. 4 or Fig. 5, the processing unit 1310 is configured to: receive a first frame from the first communication device and receive a first PPDU from the first communication device using the transceiver unit 1320. The first frame includes first indicator information. The first indicator information indicates the second communication device to perform channel sounding of the transmit antenna. The first PPDU is an NDP. The first PPDU is used by the second communication device to perform channel sounding of the transmit antenna. The first PPDU includes a first identifier field. The first identifier field indicates the identifier of the first set of transmit antennas.

[0448] When the communication device 1300 is configured to implement the function of the second communication device in the embodiment of the method shown in Fig. 4 or Fig. 5, the processing unit 1310 is further configured to: perform channel sounding of the transmit antenna based on the first PPDU using the transceiver unit 1320 to obtain a feedback result of selecting the first antenna; and transmit a second frame using the transceiver unit 1320. The second frame includes the feedback result of selecting the first antenna. The feedback result of selecting the first antenna includes a third identifier field. The third identifier field indicates the identifier of the first set of transmit antennas.

[0449] When the communication device 1300 is configured to implement the function of the second communication device in the embodiment of the method shown in Fig. 4 or Fig. 5, the processing unit 1310 is specifically configured to receive a fourth frame from the first communication device using the transceiver unit 1320. The fourth frame includes a fourth identifier field. The fourth identifier field indicates the identifier of at least one set of transmit antennas supported by the first communication device. The identifier of at least one set of transmit antennas includes the identifier of the first set of transmit antennas.

[0450] When the communication device 1300 is configured to implement the function of the second communication device in the embodiment of the method shown in Fig. 4 or Fig. 5, the processing unit 1310 is specifically configured to receive the ninth frame from the first communication device using the transceiver unit 1320. The ninth frame includes seventh indicator information. The seventh indicator information indicates the total number of sets of transmit antennas supported by the first communication device.

[0451] When the communication device 1300 is configured to implement the function of the second communication device in the embodiment of the method shown in Fig. 10, the processing unit 1310 is configured to: receive an eleventh frame from the first communication device and receive a third PPDU from the first communication device using the transceiver unit 1320. The eleventh frame includes first indicator information. The first indicator information indicates the second communication device to perform channel sounding of the transmit antenna. The third PPDU is used by the second communication device to perform channel sounding of the transmit antenna. The third PPDU includes M1 first information fields corresponding to M1 sets of transmit antennas. M1 is an integer greater than 1. The first information field is used to perform channel sounding of the transmit antenna.The first information field includes at least one of a short EHT training field, a long EHT training field, and a packet extension field.

[0452] When the communication device 1300 is configured to implement the function of the second communication device in the embodiment of the method shown in Fig. 12 or Fig. 13, the processing unit 1310 is configured to: receive a fifth frame from the first communication device using the transceiver unit 1320, where the fifth frame includes fourth indicator information, and the fourth indicator information indicates the need to perform channel sounding of the receive antenna in the first communication device; and send a second PPDU to the first communication device using the transceiver unit 1320. The second PPDU is a null data packet (NDP). The second PPDU is used by the first communication device to perform channel sounding of the receive antenna. The second PPDU includes a fifth identifier field. The fifth identifier field indicates the identifier of the first set of receive antennas.

[0453] When the communication device 1300 is configured to implement the function of the second communication device in the embodiment of the method shown in Fig. 17, the processing unit 1310 is configured to: receive a twelfth frame from the first communication device using the transceiver unit 1320, where the twelfth frame includes fourth indicator information, and the fourth indicator information indicates the need to perform channel sounding of the receive antenna to the first communication device; and send a fourth PPDU to the first communication device using the transceiver unit 1320. The fourth PPDU is used by the second communication device to perform channel sounding of the receive antenna. The fourth PPDU includes M2 second information fields corresponding to M2 sets of receive antennas. M2 is an integer greater than 1. The second information field is used to perform channel sounding of the receive antenna.The second information field includes at least one of a short EHT training field, a long EHT training field, and a packet extension field.

[0454] For a more detailed description of the processing unit 1310 and the transceiver unit 1320, please refer directly to the corresponding descriptions of the embodiment of the method shown in Fig.4, Fig.5, Fig.10, Fig.12, Fig.13 or Fig.17. The details are not described here again.

[0455] As shown in Fig. 21, the communication device 1400 includes a processing circuit 1410 and an interface circuit 1420. The processing circuit 1410 and the interface circuit 1420 are connected to each other. It is understood that the interface circuit 1420 can be a transceiver or an input / output interface. If necessary, the communication device 1400 can further include a memory configured to store instructions executed by the processing circuit, or to store input data required by the processing circuit 1410 to run instructions, or to store data generated after the processing circuit 1410 runs instructions.

[0456] When the communication device 1400 is configured to implement the method shown in Fig. 4, Fig. 5, Fig. 10, Fig. 12, Fig. 13 or Fig. 17, the processing circuit 1410 is configured to implement the function of the processing unit 1310, and the interface circuit 1420 is configured to implement the function of the transceiver unit 1320.

[0457] As shown in Fig. 22, the communication device 1500 includes a processor 1510 and a communication interface 1520. The processor 1510 and the communication interface 1520 are connected to each other. It is understood that the communication interface 1520 can be a transceiver or an input / output interface. If necessary, the communication device 1500 can further include a memory 1530 configured to store instructions executed by the processor 1510, or to store input data required by the processor 1510 to run the instructions, or to store data generated after the processor 1510 runs the instructions.

[0458] When the communication device 1500 is configured to implement the method shown in Fig. 4, Fig. 5, Fig. 10, Fig. 12, Fig. 13 or Fig. 17, the processor 1510 is configured to implement the function of the processing unit 1310, and the communication interface 1520 is configured to implement the function of the transceiver unit 1320.

[0459] When the communication device 1500 is configured to implement the function of the first communication device in the embodiment of the method shown in Fig. 4 or Fig. 5, the processor 1510 is configured to: send a first frame to the second communication device using the communication interface 1520, where the first frame includes first indicator information, and the first indicator information indicates the second communication device to perform channel sounding of the transmit antenna; and send a first PPDU to the second communication device using the communication interface 1520. The first PPDU is a null data packet (NDP). The first PPDU is used by the second communication device to perform channel sounding of the transmit antenna. The first PPDU includes a first identifier field. The first identifier field indicates the identifier of the first set of transmit antennas.

[0460] When the communication device 1500 is configured to implement the function of the first communication device in the embodiment of the method shown in Fig. 10, the processor 1510 is configured to: send an eleventh frame to the second communication device using the communication interface 1520, where the eleventh frame includes first indicator information, and the first indicator information indicates the second communication device to perform channel sounding of the transmit antenna; and send a third PPDU to the second communication device using the communication interface 1520. The third PPDU is used by the second communication device to perform channel sounding of the transmit antenna. The third PPDU includes M1 first information fields corresponding to M1 sets of transmit antennas. M1 is an integer greater than 1. The first information field is used to perform channel sounding of the transmit antenna.The first information field includes at least one of a short EHT training field, a long EHT training field, and a packet extension field.

[0461] When the communication device 1500 is configured to implement the function of the first communication device in the embodiment of the method shown in Fig. 12 or Fig. 13, the processor 1510 is configured to: send a fifth frame to the second communication device using the communication interface 1520, where the fifth frame includes fourth indicator information, and the fourth indicator information indicates the need to perform channel sounding of the receiving antenna in the first communication device; and receive a second physical protocol data unit (PPDU) from the second communication device using the communication interface 1520. The second PPDU is a null data packet (NDP). The second PPDU is used by the first communication device to perform channel sounding of the receiving antenna. The second PPDU includes a fifth identifier field. The fifth identifier field indicates the identifier of the first set of receiving antennas.

[0462] When the communication device 1500 is configured to implement the function of the first communication device in the embodiment of the method shown in Fig. 17, the processor 1510 is configured to: send a twelfth frame to the second communication device using the communication interface 1520, where the twelfth frame includes fourth indicator information, and the fourth indicator information indicates the need to perform channel sounding of the receive antenna in the first communication device; and receive a fourth physical protocol data unit (PPDU) from the second communication device using the communication interface 1520. The fourth PPDU is used by the second communication device to perform channel sounding of the receive antenna. The fourth PPDU includes M2 second information fields corresponding to M2 sets of receive antennas. M2 is an integer greater than 1. The second information field is used to perform channel sounding of the receive antenna.The second information field includes at least one of a short EHT training field, a long EHT training field, and a packet extension field.

[0463] When the communication device 1500 is configured to implement the function of the second communication device in the embodiment of the method shown in Fig. 4 or Fig. 5, the processor 1510 is configured to: receive a first frame from the first communication device using the communication interface 1520, where the first frame includes first indicator information, and the first indicator information indicates the second communication device to perform channel sounding of the transmit antenna; and receive a first physical protocol data unit (PPDU) from the first communication device using the communication interface 1520. The first PPDU is a null data packet (NDP). The first PPDU is used by the second communication device to perform channel sounding of the transmit antenna. The first PPDU includes a first identifier field. The first identifier field indicates the identifier of the first set of transmit antennas.

[0464] When the communication device 1500 is configured to implement the function of the second communication device in the embodiment of the method shown in Fig. 10, the processor 1510 is configured to: receive an eleventh frame from the first communication device using the communication interface 1520, where the eleventh frame includes first indicator information, and the first indicator information indicates the second communication device to perform channel sounding of the transmit antenna; and receive a third physical protocol data unit (PPDU) from the first communication device using the communication interface 1520. The third PPDU is used by the second communication device to perform channel sounding of the transmit antenna. The third PPDU includes M1 first information fields corresponding to M1 sets of transmit antennas. M1 is an integer greater than 1. The first information field is used to perform channel sounding of the transmit antenna.The first information field includes at least one of a short EHT training field, a long EHT training field, and a packet extension field.

[0465] When the communication device 1500 is configured to implement the function of the second communication device in the embodiment of the method shown in Fig. 12 or Fig. 13, the processor 1510 is configured to: receive a fifth frame from the first communication device using the communication interface 1520, where the fifth frame includes fourth indicator information, and the fourth indicator information indicates performing channel sounding of the receive antenna in the first communication device; and send a second physical protocol data unit (PPDU) to the first communication device using the communication interface 1520. The second PPDU is a null data packet (NDP). The second PPDU is used by the first communication device to perform channel sounding of the receive antenna. The second PPDU includes a fifth identifier field. The fifth identifier field indicates the identifier of the first set of receive antennas.

[0466] When the communication device 1500 is configured to implement the function of the second communication device in the embodiment of the method shown in Fig. 17, the processor 1510 is configured to: receive a twelfth frame from the first communication device using the communication interface 1520, where the twelfth frame includes fourth indicator information, and the fourth indicator information indicates the need to perform channel sounding of the receive antenna in the first communication device; and send a fourth physical protocol data unit (PPDU) to the first communication device using the communication interface 1520. The fourth PPDU is used by the second communication device to perform channel sounding of the receive antenna. The fourth PPDU includes M2 second information fields corresponding to M2 sets of receive antennas. M2 is an integer greater than 1. The second information field is used to perform channel sounding of the receive antenna.The second information field includes at least one of a short EHT training field, a long EHT training field, and a packet extension field.

[0467] When the communication device is a microchip used in a communication device, the microchip in the communication device implements the functions of the communication device in the previous embodiments of the method. The microchip in the communication device receives information from another module (for example, a radio frequency module or an antenna) in the communication device, where the information is transmitted by the network device to the communication device; or the microchip in the communication device transmits information to another module (for example, a radio frequency module or an antenna) in the communication device, where the information is transmitted by the communication device to the network device.

[0468] It should be understood that the processor in the embodiments of the present application may be a central processing unit (CPU) or may be another general-purpose processor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA) or other programmable logic device, a transistor logic device, a hardware component, or any combination thereof. The general-purpose processor may be a microprocessor, any conventional processor, etc.

[0469] According to the method presented in the present application, an embodiment of the present application further provides a computer program product. The computer program product includes a computer program or instructions. When the computer program or instructions are run on a computer, the computer can execute the method in any of the embodiments shown in Fig. 4, Fig. 5, Fig. 10, Fig. 12, Fig. 13, or Fig. 17.

[0470] According to the method presented in the embodiments of the present application, the present application further provides a computer-readable storage medium. The computer-readable storage medium stores a program or instructions. When the program or instructions are executed on a computer, the computer can execute the method in any of the embodiments shown in Fig. 4, Fig. 5, Fig. 10, Fig. 12, Fig. 13, or Fig. 17.

[0471] According to the method presented in the embodiments of the present application, the present application further provides a chip system. The chip system may include a processing circuit and an interface circuit. The processing circuit may perform, using the interface circuit, the method in any of the embodiments shown in Fig.4, Fig.5, Fig.10, Fig.12, Fig.13 or Fig.17. If necessary, the chip system further includes a memory. The memory is intended for storing a computer program (which may also be referred to as code or instructions). The processing circuit may be configured to call the computer program from the memory and run the computer program, so that the device in which the chip system is installed performs the method in any of the embodiments shown in Fig.4, Fig.5, Fig.10, Fig.12, Fig.13 or Fig.17.

[0472] According to the method provided in the embodiments of the present application, the present application further provides a system including the above-mentioned first communication device and the above-mentioned second communication device.

[0473] The steps of the method in the embodiments of the present application may be implemented in hardware or may be implemented by executing software instructions using a processor. The software instructions may include a corresponding software module. The software module may be stored in random access memory (RAM), flash memory, read-only memory (ROM), programmable read-only memory, erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory, a register, a hard disk, a solid-state drive (SSD), a removable hard disk, a portable read-only memory (CD-ROM), or any other form of storage medium known in the art.For example, a storage medium is connected to the processor so that the processor can read information from and write information to the storage medium. Of course, the storage medium can be a component of the processor. The processor and storage medium can be located in an ASIC. Additionally, the ASIC can be located in a communication device. Of course, the processor and storage medium can be used as separate components in a communication device.

[0474] All or some of the above embodiments may be implemented using software, hardware, firmware, or any combination thereof. When software is used to implement the embodiments, all or part of the embodiments may be implemented as a computer program product. The computer program product includes one or more computer programs or instructions. When the computer program or instructions are loaded and executed on the computer, all or some of the procedures or functions in the embodiments of the present application are performed. The computer may be a general-purpose computer, a specialized computer, a computer network, a network device, a user device, or another programmable device.A computer program or instructions may be stored on a machine-readable storage medium or may be transmitted from a machine-readable storage medium to another machine-readable storage medium. For example, a computer program or instructions may be transmitted from a website, computer, server, or data center to another website, computer, server, or data center by wire or wireless means. A machine-readable storage medium may be any usable storage medium accessible by a computer or a data storage device, such as a server or data center, incorporating one or more usable storage media.The storage medium used may be a magnetic storage medium, such as a floppy disk, hard disk, or magnetic tape; or it may be an optical storage medium, such as a digital video disc; or it may be a semiconductor storage medium, such as a solid-state drive. The machine-readable storage medium may be volatile or nonvolatile storage medium, or it may include both types of storage media: volatile storage medium and nonvolatile storage medium.

[0475] In the various embodiments of the present application, unless otherwise indicated or there is a logical conflict, terms and / or descriptions in different embodiments are consistent and may be mutually referenced, and technical characteristics in different embodiments may be combined based on their internal logical relationship to form a new embodiment.

[0476] “Plurality” in this application refers to two or more than two. The term “and / or” describes an association relationship between related objects and means that three relationships may exist. For example, A and / or B may represent the following three cases: only A exists, both A and B exist, and only B exists, where A and B may be singular or plural. In the text descriptions of this application, the symbol “ / ” indicates an “or” relationship between related objects. In the claims of this application, the symbol “ / ” indicates a “separation” relationship between related objects. “Including at least one of: A, B, or C” may mean including A; including B; including C; including A and B; including A and C; including B and C; and including A, B, and C.

[0477] It is obvious that the different numbers in the embodiments of the present application are used merely for distinction and simplicity of description and are not used to limit the scope of the embodiments of the present application. The sequential numbers of the above processes do not indicate the execution sequence, and the execution sequence of the processes should be determined based on the functions and internal logic of the processes.

Claims

1. A method for probing an antenna channel, comprising the step of: transmitting, by means of a first communication device, a first frame to a second communication device, wherein the first frame comprises first indicator information, wherein the first indicator information instructs the second communication device to perform probing of a channel of a transmitting antenna; and transmitting, by means of a first communication device, a first physical protocol data unit (PPDU) to a second communication device, wherein the first PPDU is a null data packet (NDP), the first PPDU is used by the second communication device to perform channel sounding of a transmitting antenna, the first PPDU contains a first identifier field, and the first identifier field indicates an identifier of a first set of transmitting antennas.

2. The method of claim 1, further comprising, after the step of transmitting, by the first communication device, the first PPDU to the second communication device, the step of: receiving, using the first communication device, a second frame from the second communication device, wherein the second frame contains a feedback result of the selection of the first antenna, the feedback result of the selection of the first antenna contains a third identifier field, and the third identifier field indicates the identifier of the first set of transmitting antennas.

3. The method according to claim 1 or 2, further comprising, prior to the step of transmitting, using the first communication device, the first frame to the second communication device, a step in which: transmitting, using the first communication device, a fourth frame to the second communication device, wherein the fourth frame contains a fourth identifier field, the fourth identifier field indicates the identifier of at least one set of transmitting antennas supported by the first communication device, and the identifier of at least one set of transmitting antennas contains the identifier of the first set of transmitting antennas.

4. The method according to any one of paragraphs 1-3, further comprising, prior to the step of transmitting, using the first communication device, the first frame to the second communication device, a step in which: transmitting, via the first communication device, a ninth frame to the second communication device, wherein the ninth frame comprises seventh indicator information, wherein the seventh indicator information indicates the total number of sets of transmitting antennas supported by the first communication device.

5. A method for probing an antenna channel, comprising the steps of: receiving, by means of a second communication device, a first frame from the first communication device, wherein the first frame comprises first indicator information, and the first indicator information instructs the second communication device to perform probing of a channel of the transmitting antenna; and receiving, by a second communication device, a first physical protocol data unit (PPDU) from a first communication device, wherein the first PPDU is a null data packet (NDP), the first PPDU is used by the second communication device to perform channel probing of a transmitting antenna, the first PPDU contains a first identifier field, wherein the first identifier field indicates an identifier of a first set of transmitting antennas.

6. The method of claim 5, further comprising, after the step of receiving, by the second communication device, the first PPDU, the steps of: performing, using the second communication device, probing the channel of the transmitting antenna based on the first PPDU to obtain a feedback result of the first antenna selection; and transmitting, using the second communication device, a second frame, wherein the second frame contains a first antenna selection feedback result, the first antenna selection feedback result contains a third identifier field, wherein the third identifier field indicates the identifier of the first set of transmitting antennas.

7. The method according to claim 5 or 6, further comprising, prior to the step of receiving, using the second communication device, the first frame, the step of: receiving, using a second communication device, a fourth frame from the first communication device, wherein the fourth frame comprises a fourth identifier field, the fourth identifier field indicating the identifier of at least one set of transmitting antennas supported by the first communication device, wherein the identifier of at least one set of transmitting antennas comprises the identifier of the first set of transmitting antennas.

8. The method according to any one of paragraphs 5-7, further comprising, before the step of receiving, using the second communication device, the first frame, the step of: receiving, via the second communication device, a ninth frame from the first communication device, wherein the ninth frame comprises seventh indicator information, wherein the seventh indicator information indicates the total number of sets of transmitting antennas supported by the first communication device.

9. The method according to any one of paragraphs 1-8, in which the first identifier field is located in the preamble of the first PPDU.

10. The method of any one of paragraphs 1-9, wherein the first frame further comprises a number of NDPs; and / or the first frame further comprises a second identifier field, wherein the second identifier field indicates an identifier of the first set of transmit antennas.

11. The method of claim 10, wherein the first indicator information and / or the number of NDPs is carried in at least one station information field related to the first frame and containing second indicator information, wherein the second indicator information indicates that the station information field contains information related to antenna selection; and / or the second identifier field contains some or all of the bits in at least one station information field related to the first frame and containing the second pointer information.

12. The method of claim 11, wherein the second pointer information is carried in the association identifier field of the station information field.

13. The method according to any one of paragraphs 1-12, in which the first set of transmitting antennas is one of k1 sets of transmitting antennas of the first communication device, and k1 is a positive integer; wherein k1 sets of transmitting antennas are in one-to-one correspondence with the identifiers of k1 sets of transmitting antennas.

14. A communication device comprising: a transceiver unit configured to transmit a first frame to a second communication device, wherein the first frame comprises first indicator information, and the first indicator information instructs the second communication device to perform probing of a channel of the transmitting antenna; wherein the transceiver unit is further configured to transmit a first physical protocol data unit (PPDU) to the second communication device, wherein the first PPDU is a null data packet (NDP), the first PPDU is used by the second communication device to perform channel probing of the transmitting antenna, the first PPDU contains a first identifier field, and the first identifier field indicates an identifier of the first set of transmitting antennas.

15. The communication device according to claim 14, wherein, after the communication device transmits the first PPDU to the second communication device, the transceiver unit is further configured to: receiving a second frame from a second communication device, wherein the second frame contains a feedback result of selecting the first antenna, the feedback result of selecting the first antenna contains a third identifier field, wherein the third identifier field indicates the identifier of the first set of transmitting antennas.

16. The communication device according to paragraph 14 or 15, in which, before transmitting, by the communication device, the first frame to the second communication device, the transceiver unit is additionally configured to: transmitting a fourth frame to a second communication device, wherein the fourth frame comprises a fourth identifier field, the fourth identifier field indicating an identifier of at least one set of transmitting antennas supported by the communication device, wherein the identifier of at least one set of transmitting antennas comprises an identifier of the first set of transmitting antennas.

17. A communication device according to any one of paragraphs 14-16, in which, before transmitting, by the communication device, the first frame to the second communication device, the transceiver unit is additionally configured to: transmitting a ninth frame to the second communication device, wherein the ninth frame comprises seventh indicator information, wherein the seventh indicator information indicates the total number of sets of transmit antennas supported by the communication device.

18. A communication device comprising: a transceiver unit configured to receive a first frame from a first communication device, wherein the first frame comprises first indicator information, wherein the first indicator information instructs the communication device to perform probing of a channel of a transmitting antenna; wherein the transceiver unit is further configured to receive a first physical protocol data unit (PPDU) from the first communication device, wherein the first PPDU is a null data packet (NDP), the first PPDU is used by the communication device to perform channel probing of the transmitting antenna, the first PPDU contains a first identifier field, wherein the first identifier field indicates an identifier of the first set of transmitting antennas.

19. The communication device according to claim 18, wherein after the communication device receives the first PPDU, the transceiver unit is further configured to: performing channel probing of the transmit antenna based on the first PPDU to obtain a first antenna selection feedback result; and transmitting a second frame, wherein the second frame contains a feedback result of selecting the first antenna, the feedback result of selecting the first antenna contains a third identifier field, wherein the third identifier field indicates the identifier of the first set of transmitting antennas.

20. The communication device according to paragraph 18 or 19, in which, before the communication device receives the first frame, the transceiver unit is additionally configured to: receiving a fourth frame from the first communication device, wherein the fourth frame comprises a fourth identifier field, the fourth identifier field indicating an identifier of at least one set of transmitting antennas supported by the first communication device, wherein the identifier of at least one set of antennas of the transmitting device comprises an identifier of the first set of transmitting antennas.

21. A communication device according to any one of paragraphs 18-20, in which, before the communication device receives the first frame, the transceiver unit is further configured to: receiving a ninth frame from the first communication device, wherein the ninth frame comprises seventh indicator information, wherein the seventh indicator information indicates the total number of sets of transmitting antennas supported by the first communication device.

22. The communication device according to any one of paragraphs 14-21, in which the first identifier field is located in the preamble of the first PPDU.

23. The communication device of any one of paragraphs 14-22, wherein the first frame further comprises a number of NDPs; and / or the first frame further comprises a second identifier field, and the second identifier field indicates the identifier of the first set of transmit antennas.

24. The communication device of claim 23, wherein the first indicator information and / or the number of NDPs is carried in at least one station information field related to the first frame and containing second indicator information, wherein the second indicator information indicates that the station information field contains information related to antenna selection; and / or the second identifier field contains some or all of the bits in at least one station information field related to the first frame and containing the second pointer information.

25. The communication device of claim 24, wherein the second indicator information is carried in an association identifier field in the station information field.

26. The communication device according to any one of paragraphs 14-25, in which the first set of transmitting antennas is one of k1 sets of transmitting antennas of the first communication device, where k1 is a positive integer; and k1 sets of transmitting antennas are in one-to-one correspondence with the identifiers of k1 sets of transmitting antennas.

27. A communication device comprising a processor and a communication interface, wherein the processor is configured to implement the method according to any one of paragraphs 1-4 using the communication interface.

28. A communication device comprising a processor and a communication interface, wherein the processor is configured to implement the method according to any one of paragraphs 5-13 using the communication interface.

29. A machine-readable storage medium that stores computer-executable instructions that, when executed by the computer, cause the computer to perform the method according to any one of paragraphs 1-4.

30. A machine-readable storage medium that stores computer-executable instructions that, when executed by the computer, cause the computer to perform the method according to any one of paragraphs 5-13.

31. A system of antenna channel probing microcircuits comprising a processing circuit and an interface circuit, wherein the interface circuit is configured to input and / or output signals or data; and the processing circuit is configured to execute a program executed by a computer, so that the device on which the microcircuit system is installed implements the method according to any of paragraphs 1-4.

32. A system of antenna channel probing microcircuits comprising a processing circuit and an interface circuit, wherein the interface circuit is configured to input and / or output signals or data; and the processing circuit is configured to execute a program executed by a computer, so that the device on which the microcircuit system is installed implements the method according to any of paragraphs 5-13.

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