METHODS AND DEVICES FOR TRANSFERRING DATA BLOCKS USING THE PHYSICAL LAYER PROTOCOL AND COMPUTER-READABLE RECORDS

Abstract

The invention relates to a method for transmitting physical layer protocol data units (PPDUs) and related devices, computer-readable data loggers. The method comprises the following steps: creating a PPDU, which includes a universal signal field (U-SIG), and the U-SIG includes a subfield indicating that the PPDU is a null data packet (NDP); and transmitting the PPDU. In this way, a Bfee receiving the NDP can identify the NDP earlier. This improves the performance of NDP reading by the Bfee. The PPDU is the NDP used for standards following 802.11ax. In a scenario where wireless communication is performed using a standard (e.g., 802.11be) following 802.11ax, the Bfee can perform channel estimation based on the NDP.

Description

PPDU transmission method and related devices

[0001] This application claims priority to Chinese Patent Application No. 202010506948.X, filed on June 5, 2020, entitled "Transmission Method and Related Apparatus for PPDU", the entire contents of which are incorporated herein by reference. Technical Field

[0002] This application relates to the field of wireless local area network technology, and in particular to a PPDU transmission method and related apparatus. Background Technology

[0003] In wireless systems such as Wireless Local Area Networks (WLANs), access points (APs) and stations (STAs) need to acquire channel state information in advance to perform functions such as beamforming (BF), rate control, and resource allocation. In WLANs, the process of acquiring channel state information is called channel detection. In related technologies, during channel detection, the AP first sends a null data packet announcement (NDPA) frame to notify the STAs that need to perform channel detection. Then, after a short inter-frame space (SIFS), it sends a null data packet (NDP) without a data field. The STA then uses the NDP to perform channel estimation and then feeds back channel state information (CSI) via a beamforming report (BF Report) frame. Based on the channel state information fed back by the STA, the AP then sends a Physical Layer Protocol Data Unit (PPDU).

[0004] The PPDU in the 802.11ax standard is called a high efficient (HE) PPDU, and the PPDU in the 802.11be standard is called an extremely high throughput (EHT) PPDU.

[0005] However, the related technologies only provide the structure of HE NDP for HE PPDU, and do not design the structure of EHT NDP.

[0006] Summary of the Invention

[0007] This application provides a PPDU transmission method and related apparatus, enabling AP or STA to perform channel estimation through NDP to obtain channel state information in scenarios where wireless communication is performed using standards after 802.11ax (e.g., 802.11be).

[0008] In a first aspect, this application provides a method for transmitting a PPDU, comprising: generating a Physical Layer Protocol Data Unit (PPDU), the PPDU including a General Signaling Field (U-SIG); the U-SIG including a subfield indicating that the PPDU is an Empty Data Packet (NDP); and transmitting the PPDU.

[0009] This PPDU is an NDP for standards after 802.11ax and does not contain a data field. This NDP is used for channel estimation in Bfee.

[0010] The device that transmits the NDP (Network Targeting Protocol) can be understood as the beamforming initiator (Bfer), and the device that receives the NDP and performs channel estimation based on it can be understood as the beamforming responder (Bfee). The Bfer can be either an access point (AP) or a station (STA). The Bfee can be either a station (STA) or an access point (AP).

[0011] In this embodiment, the U-SIG of the PPDU includes a subfield indicating that the PPDU is an NDP. The device receiving the NDP can determine that the PPDU is an NDP subfield based on the subfield in the U-SIG indicating that the PPDU is an NDP. This allows Bfee to prepare the process for calculating channel state information in advance, gaining more processing time, instead of having to confirm that the PPDU is an NDP subfield after calculating that the length of the data portion of the PPDU is 0. Such an NDP helps improve the efficiency of receiving NDPs.

[0012] Optionally, the subfield indicating that the PPDU is an NDP can be an NDP indicator subfield, a PPDU format subfield, or a subfield indicating the number of EHT-SIG symbols in the U-SIG.

[0013] In some embodiments, the PPDU further includes an extremely high throughput short training field (EHT-STF) adjacent to and following the U-SIG. The EHT-STF immediately follows the U-SIG. This NDP does not contain the EHT-SIG. Thus, the EHT NDP adopts the structure of the NDP provided in this application, which helps to achieve symbol alignment of the NDP transmitted in each channel when EHT NDP and HE NDP are co-transmitted in scenarios involving aggregated PPDU transmission, thereby avoiding out-of-band interference between different frequency bands.

[0014] NDP does not include EHT-SIG. U-SIG may not indicate the symbol number and modulation and coding scheme (MCS) of EHT-SIG, nor is it necessary to indicate coding-related indicators, such as the low-density parity check (LDPC) additional symbol fragmentation indicator. The data packet extension indicator can use a fixed value, so it does not need to be indicated.

[0015] Thus, the U-SIG may not include the subfield indicating the EHT-SIG symbol count, the MCS subfield, the subfield for symbols other than LDPC, and the data packet extension ambiguity subfield. Bits used to carry these fields in the U-SIG of a PPDU containing data fields can be used to carry other information in the NDP's U-SIG, or in other words, bits carrying these fields can be used to carry other fields. For example, bits carrying these fields can be used to carry the subfield indicating the EHT-LTF symbol count, allowing the NDP's U-SIG to include more information.

[0016] It should be understood that in some alternative implementations, based on the NDP structure shown in Figure 9, U-SIG may also include a subfield indicating the number of EHT-SIG symbols. This subfield indicates that the number of EHT-SIG symbols is a set value, with PPDU as the NDP. This subfield indicating the number of EHT-SIG symbols may be, but is not limited to, a subfield indicating a quantity of EHT-SIG symbols / MU-MIMO users, or a subfield solely used to indicate the number of EHT-SIG symbols.

[0017] Optionally, the U-SIG further includes a spatial stream count subfield and / or a subfield indicating the number of EHT-LTF symbols in the ultra-high throughput long training field, wherein the spatial stream count subfield and / or the subfield indicating the number of EHT-LTF symbols indicates the space-time stream count and the number of EHT-LTF symbols. The subfield indicating the number of EHT-LTF symbols may, for example, be the number of EHT-LTF symbols, an intermediate preamble, and a Doppler subfield, or it may be a separate EHT-LTF symbol count subfield.

[0018] Secondly, embodiments of this application also provide a method for transmitting a PPDU, comprising:

[0019] Generate a PPDU, wherein the PPDU is an NDP, the PPDU includes an Extremely High Throughput Signaling Field (EHT-SIG), the EHT-SIG has a symbol count of 1, and the EHT-SIG uses BPSK, 1 / 2 code rate modulation; transmit the PPDU.

[0020] This PPDU is an NDP for standards after 802.11ax and does not contain a data field. This NDP is used for channel probing by Bfee.

[0021] In the technical solution of this application, the number of EHT-SIG symbols in NDP is 1. This NDP structure can reduce the number of EHT-SIG symbols, thereby saving the overhead required for transmitting NDP.

[0022] In some implementations, the PPDU further includes a general signaling field U-SIG, which includes a subfield indicating the EHT-SIG symbol count. This subfield indicates that the EHT-SIG symbol count is any value greater than or equal to 1. This subfield indicating the EHT-SIG symbol count can be, for example, but not limited to, the EHT-SIG symbol count or MU-MIMO user count subfield, or an EHT-SIG symbol count subfield used solely to indicate the EHT-SIG symbol count.

[0023] The subfield indicating the EHT-SIG symbol count indicates that the EHT-SIG symbol count is 1. The Bfee receiving this NDP can calculate that the length of the data field in the PPDU is 0, thus determining that the PPDU is an NDP. The subfield indicating the EHT-SIG symbol count indicates that the EHT-SIG symbol count is greater than 1. The Bfee can calculate that the length of the data field in the PPDU is less than 0, thus determining that the PPDU is an NDP.

[0024] In some implementations, the subfield indicating the number of symbols in the EHT-SIG indicates that the number of symbols in the EHT-SIG is 1, and the U-SIG further includes a coding and modulation strategy (MCS) subfield, which indicates that the EHT-SIG uses BPSK, 1 / 2 code rate modulation.

[0025] In this way, Bfee can identify a PPDU as an NDP without calculating the symbol count in the data field. This allows Bfee to prepare the channel state information calculation process in advance, gaining more processing time, instead of needing to confirm that the PPDU is an NDP subfield after calculating that the length of the data portion of the PPDU is 0. This improved NDP reading efficiency for Bfee helps improve its NDP reading efficiency.

[0026] In some implementations, the NDP indicator subfield or PPDU format subfield in the U-SIG indicates that the PPDU is in uncompressed mode. In the case of uncompressed mode, the EHT-SIG symbol count or MU-MIMO user count indicator subfield in the U-SIG indicates the EHT-SIG symbol count. This enables the EHT-SIG symbol count or MU-MIMO user count indicator subfield to indicate that the EHT-SIG symbol count is 1.

[0027] In some implementations, the space-time stream number subfield and / or the EHT-LTF symbol number subfield in the EHT-SIG indicate both the space-time stream number and the EHT-LTF symbol number. This EHT-LTF symbol number subfield can be, for example, the EHT-LTF symbol number, intermediate preamble, and Doppler subfield, or it can be a separate EHT-LTF symbol number subfield.

[0028] Thirdly, this application also provides a method for transmitting a PPDU, comprising: generating a PPDU, wherein the PPDU is an NDP, the PPDU includes an EHT-SIG, the EHT-SIG includes an AID subfield indicating an associated identifier AID, the AID being used to indicate information related to a user of the NDP; and sending the PPDU.

[0029] In this way, Bfee can determine the relevant information of NDP users based on the AID in the NDP's EHT-SIG. This allows it to accurately determine whether it is a user that needs to perform channel sensing and report beamforming.

[0030] The PPDU in this scheme is an NDP for standards after 802.11ax, and does not contain a data field. This NDP is used for channel probing by Bfee.

[0031] In some implementations, the user of the NDP is a station, and the AID subfield indicates the AID of that station. Thus, the station corresponding to this AID can determine itself as a station that needs to perform channel sensing and report beamforming results based on the AID in the NDP.

[0032] In this way, even if the station fails to read the user field containing its own AID due to incorrect reading of the NDPA frame, the station can still determine itself as a station that needs to perform channel probing and report beamforming based on the channel probing results, thereby improving the success rate of Bfer obtaining beamforming reports.

[0033] Furthermore, if a device whose AID does not match the AID indicated by the AID subfield receives the NDP and reads that the AID indicated by the AID subfield does not match its own AID, it will not continue to receive the NDP, thereby saving power consumption for devices whose AID does not match the AID indicated by the AID subfield.

[0034] In some implementations, the users of the NDP are multiple stations, and the AID indicated by the user field is 0, indicating that the NDP is sent in a broadcast manner. In such an implementation, the EHT-SIG of the NDPA frame sent before the NDP includes multiple station fields, and the AID subfield of these station fields indicates the AID of the station that needs to perform channel sounding and report beamforming. Thus, when a station receives the NDP, based on the AID subfield being 0, it determines that the users of the NDP are multiple stations. Therefore, all stations that receive the NDP, or the stations corresponding to the AID indicated by the user field in the NDPA frame, continue to receive the NDP to obtain channel state information and report beamforming.

[0035] In some implementations, the user of the NDP is an access point, and the AID indicated by the AID subfield is a set value. This set value can be broadcast by the AP or it can be a standard, predetermined fixed value, such as 2045. It should be understood that the set value can also be other values.

[0036] In some embodiments, the PPDU further includes a U-SIG, which includes a format subfield and / or a compression subfield, wherein the format subfield or the compression subfield indicates that the PPDU is an NDP. This allows Bfee to identify the PPDU as an NDP based on the format subfield or the compression subfield after recognizing it. This enables Bfee to identify the PPDU as an NDP before calculating the symbol count of the data field in the PPDU to be 0, and to read the PPDU according to the NDP format. This allows Bfee to prepare the channel state information calculation process in advance, gain more processing time, and improve the efficiency of NDP reading.

[0037] In some implementations, the PPDU further includes U-SIG and EHT-LTF, where U-SIG includes a space-time stream number subfield indicating the number of space-time streams, and the number of EHT-LTFs is greater than the number of space-time streams. Thus, in scenarios involving the transmission of aggregated PPDU structures, when multiple NDPs with identical structures are transmitted on different channels, even if the spatial streams on each channel are different, the number of symbols in the EHT-LTF of each NDP transmitted on each channel can be the same. This helps to align the symbols of each field of each NDP, thereby avoiding out-of-band interference between different frequency bands.

[0038] Fourthly, this application also provides a method for transmitting a PPDU, comprising: receiving a PPDU, wherein the PPDU is an NDP, the PPDU includes a general signaling field U-SIG; the U-SIG includes a subfield indicating that the PPDU is an empty data packet NDP; and performing channel estimation through the NDP.

[0039] This PPDU is an NDP for standards after 802.11ax and does not contain a data field. This NDP is used for channel probing by Bfee.

[0040] In this embodiment, the U-SIG of the PPDU includes a subfield indicating that the PPDU is an NDP. The device receiving the NDP can determine that the PPDU is an NDP subfield based on the subfield in the U-SIG indicating that the PPDU is an NDP. This allows Bfee to prepare the process for calculating channel state information in advance, gaining more processing time, instead of having to confirm that the PPDU is an NDP subfield after calculating that the length of the data portion of the PPDU is 0. Such an NDP helps improve the efficiency of receiving NDPs.

[0041] Optionally, the subfield indicating that the PPDU is an NDP can be an NDP indicator subfield, a PPDU format subfield, or a subfield indicating the number of EHT-SIG symbols in the U-SIG.

[0042] In some embodiments, the PPDU further includes an extremely high throughput short training field (EHT-STF) adjacent to and following the U-SIG. The EHT-STF immediately follows the U-SIG. This NDP does not contain the EHT-SIG. Thus, the EHT NDP adopts the structure of the NDP provided in this application, which helps to achieve symbol alignment of the NDP transmitted in each channel when EHT NDP and HE NDP are co-transmitted in scenarios involving aggregated PPDU transmission, thereby avoiding out-of-band interference between different frequency bands.

[0043] NDP does not include EHT-SIG. U-SIG may not indicate the symbol count and MCS of EHT-SIG, nor is it necessary to indicate encoding-related indicators, such as the LDPC additional symbol fragmentation indicator. The data packet extension indicator can use a fixed value, so it does not need to be indicated.

[0044] Thus, the U-SIG may not include the subfield indicating the EHT-SIG symbol count, the MCS subfield, the subfield for symbols other than LDPC, and the data packet extension ambiguity subfield. Bits used to carry these fields in the U-SIG of a PPDU containing data fields can be used to carry other information in the NDP's U-SIG, or in other words, bits carrying these fields can be used to carry other fields. For example, bits carrying these fields can be used to carry the subfield indicating the EHT-LTF symbol count, allowing the NDP's U-SIG to include more information.

[0045] It should be understood that in some alternative implementations, based on the NDP structure shown in Figure 9, U-SIG may also include a subfield indicating the number of EHT-SIG symbols. This subfield indicates that the number of EHT-SIG symbols is a set value, signifying that the PPDU is an NDP. This subfield indicating the number of EHT-SIG symbols may be, but is not limited to, a subfield indicating a quantity of EHT-SIG symbols / MU-MIMO users, or a subfield simply indicating the number of EHT-SIG symbols.

[0046] Optionally, the U-SIG further includes a spatial stream count subfield and / or a subfield indicating the number of EHT-LTF symbols in the ultra-high throughput long training field. The spatial stream count subfield and / or the subfield indicating the number of EHT-LTF symbols are used to indicate the space-time stream count and the number of EHT-LTF symbols. The subfield indicating the number of EHT-LTF symbols can be, for example, the number of EHT-LTF symbols, an intermediate preamble, and a Doppler subfield, or it can be a separate EHT-LTF symbol count subfield.

[0047] Fifthly, this application also provides a method for transmitting a PPDU, comprising: receiving a PPDU, wherein the PPDU is an NDP, the PPDU includes an Extremely High Throughput Signaling Field (EHT-SIG), the EHT-SIG has a symbol count of 1, and the EHT-SIG uses BPSK, 1 / 2 code rate modulation; and performing channel estimation through the NDP.

[0048] This PPDU is an NDP for standards after 802.11ax and does not contain a data field. This NDP is used for channel probing by Bfee.

[0049] In the technical solution of this application, the number of EHT-SIG symbols in NDP is 1. This NDP structure can reduce the number of EHT-SIG symbols, thereby saving the overhead required for transmitting NDP.

[0050] In some implementations, the PPDU further includes a general signaling field U-SIG, which includes a subfield indicating the EHT-SIG symbol count. This subfield indicates that the EHT-SIG symbol count is any value greater than or equal to 1. This subfield indicating the EHT-SIG symbol count can be, for example, but not limited to, the EHT-SIG symbol count or MU-MIMO user count subfield, or an EHT-SIG symbol count subfield used solely to indicate the EHT-SIG symbol count.

[0051] The subfield indicating the EHT-SIG symbol count indicates that the EHT-SIG symbol count is 1. The Bfee receiving this NDP can calculate that the length of the data field in the PPDU is 0, thus determining that the PPDU is an NDP. The subfield indicating the EHT-SIG symbol count indicates that the EHT-SIG symbol count is greater than 1. The Bfee can calculate that the length of the data field in the PPDU is less than 0, thus determining that the PPDU is an NDP.

[0052] In some implementations, the subfield indicating the EHT-SIG symbol count indicates that the EHT-SIG symbol count is 1. The U-SIG also includes a coding and modulation strategy (MCS) subfield, which indicates that the EHT-SIG uses BPSK, 1 / 2 code rate modulation. In this way, Bfee can identify the PPDU as an NDP without calculating the symbol count of the data field. This allows Bfee to prepare the channel state information calculation process in advance, gaining more processing time, instead of needing to calculate the length of the PPDU's data portion as 0 before confirming that the PPDU is an NDP. This improved NDP reading efficiency for Bfee.

[0053] In some implementations, the NDP indicator subfield or PPDU format subfield in the U-SIG indicates that the PPDU is in uncompressed mode. In the case of uncompressed mode, the EHT-SIG symbol count or MU-MIMO user count indicator subfield in the U-SIG indicates the EHT-SIG symbol count. This enables the EHT-SIG symbol count or MU-MIMO user count indicator subfield to indicate that the EHT-SIG symbol count is 1.

[0054] In some implementations, the space-time stream number subfield and / or the EHT-LTF symbol number subfield in the EHT-SIG indicate both the space-time stream number and the EHT-LTF symbol number. This EHT-LTF symbol number subfield can be, for example, the EHT-LTF symbol number, intermediate preamble, and Doppler subfield, or it can be a separate EHT-LTF symbol number subfield.

[0055] Sixthly, this application also provides a method for transmitting a PPDU, comprising:

[0056] Receive a PPDU, wherein the PPDU is an NDP, the PPDU includes an EHT-SIG, the EHT-SIG includes an AID subfield indicating an associated identifier AID, the AID being used to indicate information related to the user of the NDP;

[0057] Channel estimation is performed using the NDP.

[0058] In this way, Bfee can determine the relevant information of NDP users based on the AID in the NDP's EHT-SIG. This allows it to accurately determine whether it is a user that needs to perform channel sensing and report beamforming.

[0059] The PPDU in this scheme is an NDP for standards after 802.11ax, and does not contain a data field. This NDP is used for channel probing by Bfee.

[0060] In some implementations, the user of the NDP is a station, and the AID subfield indicates the AID of that station. Thus, the station corresponding to this AID can determine itself as a station that needs to perform channel sensing and report beamforming results based on the AID in the NDP.

[0061] In this way, even if a station fails to read the user field containing its own AID due to incorrect reading of the NDPA frame, it can still determine itself as a station that needs to perform channel probing and report beamforming based on the channel probing results, thereby improving the success rate of the Bfer obtaining beamforming reports. Furthermore, devices whose AID does not match the AID indicated by the AID subfield will not continue receiving the NDP after receiving it, as they will find that the AID indicated by the AID subfield does not match their own AID. This saves power consumption for devices whose AID does not match the AID indicated by the AID subfield.

[0062] In some implementations, the users of the NDP are multiple stations, and the AID indicated by the user field is 0, indicating that the NDP is sent in a broadcast manner. In such an implementation, the EHT-SIG of the NDPA frame sent before the NDP includes multiple station fields, and the AID subfield of these station fields indicates the AID of the station that needs to perform channel sounding and report beamforming. Thus, when a station receives the NDP, based on the AID subfield being 0, it determines that the users of the NDP are multiple stations. Therefore, all stations that receive the NDP, or the stations corresponding to the AID indicated by the user field in the NDPA frame, continue to receive the NDP to obtain channel state information and report beamforming.

[0063] In some implementations, the user of the NDP is an access point, and the AID indicated by the AID subfield is a set value. This set value can be broadcast by the AP or it can be a standard, predetermined fixed value, such as 2045. It should be understood that the set value can also be other values.

[0064] In some implementations, the PPDU further includes a U-SIG, which includes a format subfield and / or a compression subfield, the format subfield or the compression subfield indicating that the PPDU is an NDP. Thus, after Bfee identifies the PPDU, it can determine that the PPDU is an NDP based on the format subfield or the compression subfield. This allows Bfee to identify the PPDU as an NDP before calculating the symbol count of the data field in the PPDU to be 0, and to read the PPDU according to the NDP format. This enables Bfee to prepare the channel state information calculation process in advance, gain more processing time, and improve the efficiency of NDP reading.

[0065] In some implementations, the PPDU further includes U-SIG and EHT-LTF, where U-SIG includes a space-time stream number subfield indicating the number of space-time streams, and the number of EHT-LTFs is greater than the number of space-time streams. Thus, in scenarios involving the transmission of aggregated PPDU structures, when multiple NDPs with identical structures are transmitted on different channels, even if the spatial streams on each channel are different, the number of symbols in the EHT-LTF of each NDP transmitted on each channel can be the same. This helps to align the symbols of each field of each NDP, thereby avoiding out-of-band interference between different frequency bands.

[0066] In a seventh aspect, this application also provides a transmission apparatus, including a processing unit and a transmitting unit. The processing unit is used to generate a PPDU, the PPDU including a general signaling field U-SIG; the U-SIG includes a subfield indicating that the PPDU is an empty data packet (NDP); the transmitting unit is used to transmit the PPDU.

[0067] In this way, the Bfee receiving the NDP can determine that the PPDU is an NDP subfield based on the subfield indicating that the PPDU is an NDP in the U-SIG. This allows the Bfee to prepare the channel state information calculation process in advance, gaining more processing time, instead of having to confirm that the PPDU is an NDP subfield after calculating that the length of the PPDU's data portion is 0. This improved NDP reception efficiency for the Bfee.

[0068] The transmission device can be understood as a Bfer. This transmission device can be, for example, an access point or a site. Alternatively, the transmission device can be deployed at an access point or site.

[0069] In some implementations, the PPDU also includes an extremely high throughput short training field, EHT-STF, which is adjacent to and follows the U-SIG.

[0070] In some implementations, the subfield indicating that the PPDU is an NDP is an NDP indicator subfield, a PPDU format subfield, or a subfield indicating the number of EHT-SIG symbols in the U-SIG.

[0071] In some implementations, the U-SIG further includes a spatial stream count subfield and / or a subfield indicating the number of EHT-LTF symbols in the ultra-high throughput long training field, wherein the spatial stream count subfield and / or the subfield indicating the number of EHT-LTF symbols indicates the number of space-time streams and the number of EHT-LTF symbols.

[0072] Eighthly, this application also provides a transmission apparatus including a processing unit and a transmitting unit. The processing unit 1301 is used to generate a PPDU, wherein the PPDU is an NDP, and the PPDU includes an Extremely High Throughput Signaling Field (EHT-SIG), wherein the EHT-SIG has a symbol count of 1 and uses BPSK, 1 / 2 code rate modulation. The transmitting unit is used to transmit the PPDU. In this way, the symbol count of the EHT-SIG can be reduced, thereby saving the overhead required for transmitting the NDP.

[0073] The transmission device can be understood as a Bfer. This transmission device can be, for example, an access point or a site. Alternatively, the transmission device can be deployed at an access point or site.

[0074] In some implementations, the PPDU further includes a general signaling field U-SIG, which includes a subfield indicating the number of EHT-SIG symbols, wherein the subfield indicating the number of EHT-SIG symbols is any value greater than or equal to 1.

[0075] In some implementations, the subfield indicating the number of symbols in the EHT-SIG indicates that the number of symbols in the EHT-SIG is 1, and the U-SIG further includes a coding and modulation strategy (MCS) subfield, which indicates that the EHT-SIG uses BPSK, 1 / 2 code rate modulation.

[0076] In some implementations, the NDP indicator subfield or PPDU format subfield in the U-SIG indicates that the PPDU is in uncompressed mode.

[0077] In some implementations, the space-time stream number subfield and / or the EHT-LTF symbol number subfield in the EHT-SIG indicate the space-time stream number and the EHT-LTF symbol number.

[0078] Ninthly, this application also provides a transmission apparatus, including a processing unit and a transmitting unit. The processing unit is used to generate a PPDU, wherein the PPDU is an NDP, the PPDU includes an EHT-SIG, the EHT-SIG includes an AID subfield indicating an associated identifier AID, the AID being used to indicate information related to a user of the NDP; the transmitting unit is used to transmit the PPDU.

[0079] In this way, Bfee can determine the relevant information of NDP users based on the AID in the NDP's EHT-SIG. This allows it to accurately determine whether it is a user that needs to perform channel sensing and report beamforming.

[0080] The transmission device can be understood as a Bfer. This transmission device can be, for example, an access point or a site. Alternatively, the transmission device can be deployed at an access point or site.

[0081] In some implementations, the user of the NDP is a site, and the AID indicated by the AID subfield is the AID of the site.

[0082] In some implementations, the NDP user is multiple sites, and the AID indicated by the user field is 0, indicating that the NDP is sent in a broadcast manner.

[0083] In some implementations, the user of the NDP is an access point, and the AID indicated by the AID subfield is a set value.

[0084] In some implementations, the PPDU further includes a U-SIG, which includes a format subfield and / or a compression subfield, the format subfield or the compression subfield indicating that the PPDU is an NDP.

[0085] In some implementations, the PPDU further includes U-SIG and EHT-LTF, wherein the U-SIG includes a space-time stream number subfield indicating the space-time stream number, and the number of EHT-LTFs is greater than the space-time stream number.

[0086] In a tenth aspect, this application also provides a transmission apparatus, including a receiving unit and a processing unit. The receiving unit is used to receive a PPDU, wherein the PPDU is an NDP, and the PPDU includes a general signaling field U-SIG; the U-SIG includes a subfield indicating that the PPDU is an empty data packet NDP; the processing unit is used to perform channel estimation through the NDP.

[0087] In this way, the Bfee receiving the NDP can determine that the PPDU is an NDP subfield based on the subfield indicating that the PPDU is an NDP in the U-SIG. This allows the Bfee to prepare the channel state information calculation process in advance, gaining more processing time, instead of having to confirm that the PPDU is an NDP subfield after calculating that the length of the PPDU's data portion is 0. This improved NDP reception efficiency for the Bfee.

[0088] The transmission device can be understood as Bfee. The transmission device can be, for example, a site or access point, or the transmission device can be deployed at a site or access point.

[0089] In some implementations, the PPDU also includes an extremely high throughput short training field, EHT-STF, which is adjacent to and follows the U-SIG.

[0090] In some implementations, the subfield indicating that the PPDU is an NDP is an NDP indicator subfield, a PPDU format subfield, or a subfield indicating the number of EHT-SIG symbols in the U-SIG.

[0091] In some implementations, the U-SIG further includes a spatial stream count subfield and / or a subfield indicating the number of EHT-LTF symbols in the ultra-high throughput long training field, wherein the spatial stream count subfield and / or the subfield indicating the number of EHT-LTF symbols indicates the number of space-time streams and the number of EHT-LTF symbols.

[0092] Eleventhly, this application also provides a transmission apparatus, including a receiving unit and a processing unit. The receiving unit is used to receive a PPDU, wherein the PPDU is an NDP, and the PPDU includes an Extremely High Throughput Signaling Field (EHT-SIG), wherein the EHT-SIG has a symbol count of 1 and uses BPSK, 1 / 2 code rate modulation. The processing unit is used to perform channel estimation using the NDP. This reduces the symbol count of the EHT-SIG, thereby saving the overhead required for transmitting the NDP.

[0093] The transmission device can be understood as Bfee. The transmission device can be, for example, a site or access point, or the transmission device can be deployed at a site or access point.

[0094] In some implementations, the PPDU further includes a general signaling field U-SIG, which includes a subfield indicating the number of EHT-SIG symbols, wherein the subfield indicating the number of EHT-SIG symbols is any value greater than or equal to 1.

[0095] In some implementations, the NDP indicator subfield or PPDU format subfield in the U-SIG indicates that the PPDU is in uncompressed mode.

[0096] In some implementations, the subfield indicating the number of symbols in the EHT-SIG indicates that the number of symbols in the EHT-SIG is 1, and the U-SIG further includes a coding and modulation strategy (MCS) subfield, which indicates that the EHT-SIG uses BPSK, 1 / 2 code rate modulation.

[0097] In some implementations, the space-time stream number subfield and / or the EHT-LTF symbol number subfield in the EHT-SIG indicate the space-time stream number and the EHT-LTF symbol number.

[0098] In a twelfth aspect, this application also provides a transmission apparatus, including a receiving unit and a processing unit. The receiving unit is used to receive a PPDU, wherein the PPDU is an NDP, the PPDU includes an Extremely High Throughput Signaling Field (EHT-SIG), the EHT-SIG has a symbol count of 1, and the EHT-SIG uses BPSK, 1 / 2 code rate modulation. The processing unit is used to perform channel estimation through the NDP.

[0099] In this way, Bfee can determine the relevant information of NDP users based on the AID in the NDP's EHT-SIG. This allows it to accurately determine whether it is a user that needs to perform channel sensing and report beamforming.

[0100] The transmission device can be understood as Bfee. The transmission device can be, for example, a site or access point, or the transmission device can be deployed at a site or access point.

[0101] In some implementations, the user of the NDP is a site, and the AID indicated by the AID subfield is the AID of the site.

[0102] In some implementations, the NDP user is multiple sites, and the AID indicated by the user field is 0, indicating that the NDP is sent in a broadcast manner.

[0103] In some implementations, the user of the NDP is an access point, and the AID indicated by the AID subfield is a set value.

[0104] In some implementations, the PPDU further includes a U-SIG, which includes a format subfield and / or a compression subfield, the format subfield or the compression subfield indicating that the PPDU is an NDP.

[0105] In some implementations, the PPDU further includes U-SIG and EHT-LTF, wherein the U-SIG includes a space-time stream number subfield indicating the space-time stream number, and the number of EHT-LTFs is greater than the space-time stream number.

[0106] For details regarding the embodiments of the above-mentioned transmission devices, please refer to the relevant content of the embodiments of the PPDU transmission method described above. Further details will not be provided here.

[0107] In a thirteenth aspect, embodiments of this application also provide a PPDU transmission apparatus, which may include a processor, a transceiver, and optionally a memory. When the processor executes a computer program or instructions in the memory, the methods of any of the embodiments of the first to sixth aspects described above are performed. This transmission apparatus can be understood as a communication device. It can be a station or an access point.

[0108] In a fourteenth aspect, embodiments of this application also provide a computer-readable storage medium storing computer instructions that instruct a communication device to perform the method of any of the embodiments of the first to eighth aspects described above.

[0109] In a fifteenth aspect, embodiments of this application also provide a computer program product comprising a computer program that, when run on a computer, causes the computer to perform the methods of any of the embodiments of the first to sixth aspects described above.

[0110] In a sixteenth aspect, this application also provides a processor for executing the methods of any of the embodiments of the first to sixth aspects described above. During the execution of these methods, the processes of sending and receiving the aforementioned information can be understood as the process by which the processor outputs the aforementioned information, and the process by which the processor receives the input information. Specifically, when outputting the aforementioned information, the processor outputs the aforementioned information to a transceiver so that the transceiver can transmit it.

[0111] Furthermore, after the aforementioned information is output by the processor, it may require further processing before reaching the transceiver. Similarly, when the processor receives the aforementioned input information, the transceiver receives the information and inputs it into the processor. Furthermore, after the transceiver receives the aforementioned information, it may require further processing before being input into the processor.

[0112] In this way, the transmission, receiving, and other operations involved in the processor can be more generally understood as processor output and receiving, input, and other operations, rather than transmission, receiving, and receiving operations directly performed by the radio frequency circuit and antenna, unless otherwise specified or contradicted by their actual function or internal logic in the relevant description.

[0113] In specific implementations, the processor can be a dedicated processor for executing these methods, or it can be a processor that executes computer instructions stored in memory to execute these methods, such as a general-purpose processor. The memory can be a non-transitory memory, such as read-only memory (ROM), which can be integrated with the processor on the same chip or disposed on different chips. The embodiments of the present invention do not limit the type of memory or the arrangement of the memory and the processor.

[0114] In a seventeenth aspect, this application provides a chip system including a processor and an interface for supporting a communication transmission device in implementing the functions involved in the methods of any one of the first to sixth aspects, such as determining or processing at least one of the data and information involved in the aforementioned methods. In one possible design, the chip system further includes a memory for storing necessary information and data of the aforementioned PPDU transmission device. This chip system may be composed of chips or may include chips and other discrete devices.

[0115] In an eighteenth aspect, this application provides a functional entity for implementing the method described in any one of the first to sixth aspects. Attached Figure Description

[0116] Figure 1 is a schematic diagram of the network architecture of the communication system involved in the embodiments of this application;

[0117] Figure 2 is a schematic diagram of the transmission device of PPDU involved in the embodiments of this application;

[0118] Figure 3 is a schematic diagram of the structure of a chip provided in an embodiment of this application;

[0119] Figure 4A is a schematic diagram of the structure of a HE SU PPDU containing data fields;

[0120] Figure 4B is a schematic diagram of the structure of a HE MU PPDU containing data fields;

[0121] Figure 4C is a schematic diagram of the HE DDP structure;

[0122] Figure 5 is a schematic diagram of the structure of an EHT PPDU containing data fields according to an embodiment of this application;

[0123] Figure 6 is a flowchart illustrating the PPDU transmission method according to an embodiment of this application;

[0124] Figure 7 is a schematic diagram of the aggregated PPDU transmission scenario involved in the embodiments of this application;

[0125] Figure 8 is a schematic diagram of another scenario involving aggregated PPDU transmission in an embodiment of this application;

[0126] Figure 9 is a schematic diagram of the structure of the NDP according to an embodiment of this application;

[0127] Figure 10 is a schematic diagram of another scenario involving aggregated PPDU transmission in the embodiments of this application;

[0128] Figure 11 is a schematic diagram of the structure of an NDP according to another embodiment of this application;

[0129] Figure 12 is a schematic diagram of the transmission device according to an embodiment of this application;

[0130] Figure 13 is a schematic diagram of the transmission device according to an embodiment of this application;

[0131] Figure 14 is a schematic diagram of the transmission device according to an embodiment of this application;

[0132] Figure 15 is a schematic diagram of the transmission device according to an embodiment of this application;

[0133] Figure 16 is a schematic diagram of the transmission device according to an embodiment of this application;

[0134] Figure 17 is a schematic diagram of the transmission device according to an embodiment of this application. Detailed Implementation

[0135] The technical solutions in this application will now be described with reference to the accompanying drawings.

[0136] Taking Figure 1 as an example, the network structure to which the data transmission method described in this application is applicable is shown. Figure 1 is a schematic diagram of the network structure provided in an embodiment of this application. This network structure may include one or more access point (AP) type stations and one or more non-access point type stations (non-AP STAs). For ease of description, the access point type station is referred to as an access point (AP), and the non-access point type station is referred to as a station (STA). APs are, for example, AP1 and AP2 in Figure 1, and STAs are, for example, STA1, STA2, and STA3 in Figure 1.

[0137] Access points, which are the points through which terminal devices (such as mobile phones) access wired (or wireless) networks, are primarily deployed in homes, buildings, and campuses, with a typical coverage radius of tens to hundreds of meters. They can also be deployed outdoors. An access point acts as a bridge connecting wired and wireless networks, its main function being to connect various wireless network clients together and then connect the wireless network to the Ethernet. Specifically, access points can be terminal devices (such as mobile phones) or network devices (such as routers) equipped with wireless fidelity (WiFi) chips.

[0138] The access point can be a device that supports the 802.11be standard. The access point can also be a device that supports various wireless local area networks (WLAN) standards within the 802.11 family, such as 802.11ax, 802.11ac, 802.11n, 802.11g, 802.11b, and 802.11a. The access point in this application can be a high-efficiency (HE) AP or an extra-high throughput (EHT) AP, or it can be an access point compatible with a future generation of WiFi standards.

[0139] An access point may include a processor and a transceiver. The processor is used to control and manage the actions of the access point, and the transceiver is used to receive or send information.

[0140] A site can be a wireless communication chip, wireless sensor, or wireless communication terminal, and can also be referred to as a user. For example, a site can be a mobile phone that supports WiFi communication, a tablet computer that supports WiFi communication, a set-top box that supports WiFi communication, a smart TV that supports WiFi communication, a smart wearable device that supports WiFi communication, an in-vehicle communication device that supports WiFi communication, and a computer that supports WiFi communication, etc.

[0141] Optionally, the site can support the 802.11be standard. The site can also support various wireless local area networks (WLAN) standards of the 802.11 family, such as 802.11ax, 802.11ac, 802.11n, 802.11g, 802.11b, and 802.11a.

[0142] A site may include a processor and a transceiver. The processor is used to control and manage the actions of the access point, and the transceiver is used to receive or send information.

[0143] The access point in this application can be a high efficient (HE) STA or an extrameally high throughput (EHT) STA, or a STA that is compatible with a future generation of WiFi standards.

[0144] For example, access points and sites can be devices used in the Internet of Vehicles (IoV), IoT nodes and sensors in the Internet of Things (IoT), smart cameras, smart remote controls, smart water and electricity meters in smart homes, and sensors in smart cities.

[0145] The access points and sites involved in the embodiments of this application can also be collectively referred to as PPDU transmission devices, which may include hardware structures and software modules, and implement the above functions in the form of hardware structures, software modules, or hardware structures plus software modules. One of the above functions can be implemented in the form of hardware structures, software modules, or hardware structures plus software modules.

[0146] Figure 2 is a schematic diagram of a PPDU transmission device provided in an embodiment of this application. As shown in Figure 2, the transmission device 200 may include: a processor 201, a transceiver 205, and optionally a memory 202.

[0147] The transceiver 205, also known as a transceiver unit, transceiver, or transceiver circuit, is used to implement transceiver functions. The transceiver 205 may include a receiver and a transmitter. The receiver, also known as a receiver or receiving circuit, is used to implement the receiving function; the transmitter, also known as a transmitter or transmitting circuit, is used to implement the transmitting function.

[0148] The memory 202 may store computer programs, software code, or instructions 204, which may also be referred to as firmware. The processor 201 can control the MAC layer and PHY layer by running the computer programs, software code, or instructions 203 therein, or by calling the computer programs, software code, or instructions 204 stored in the memory 202, to implement the data transmission methods provided in the following embodiments of this application.

[0149] The processor 201 can be a central processing unit (CPU), and the memory 202 can be, for example, a read-only memory (ROM) or a random access memory (RAM).

[0150] The processor 201 and transceiver 205 described in this application can be implemented on integrated circuits (ICs), analog ICs, radio frequency integrated circuits (RFICs), mixed-signal ICs, application-specific integrated circuits (ASICs), printed circuit boards (PCBs), electronic devices, etc.

[0151] The aforementioned transmission device 200 may also include an antenna 206. The modules included in the transmission device 200 are merely illustrative examples, and this application does not impose any limitations on them.

[0152] As mentioned above, the transmission device 200 described in the embodiments above can be an access point or a site, but the scope of the transmission device described in this application is not limited to this, and the structure of the transmission device is not limited to FIG2. The transmission device can be a standalone device or can be part of a larger device. For example, the implementation of the transmission device can be:

[0153] (1) A standalone integrated circuit IC, or chip, or chip system or subsystem; (2) A collection of one or more ICs, optionally including storage components for storing data or instructions; (3) A module that can be embedded in other devices; (4) Receivers, smart terminals, wireless devices, handheld devices, mobile units, vehicle-mounted devices, cloud devices, artificial intelligence devices, etc.; (5) Others, etc.

[0154] When the transmission device is implemented as a chip or chip system, please refer to the structural diagram of the chip or chip system shown in Figure 3. The chip or chip system shown in Figure 3 includes a processor 301 and an interface 302. The number of processors 301 can be one or more, and the number of interfaces 302 can be multiple. Optionally, the chip or chip system may include a memory 303.

[0155] This application provides embodiments that do not limit the scope and applicability of the claims. Those skilled in the art can make adaptive changes to the function and deployment of the elements involved in this application without departing from the scope of the embodiments, or omit, substitute, or add various processes or components as appropriate.

[0156] In related technologies, the device that sends NDPA frames and NDP can be understood as a beamforming initiator (Bfer), and the device that receives NDPA frames and NDP and feeds back beamforming reports based on NDPA and NDP can be understood as a beamforming responder (Bfee). A Bfer can be either an access point (AP) or a stand-in point (STA). A Bfee can be either a stand-in point (STA) or an access point (AP).

[0157] In 802.11ax, different PPDUs were designed for single-user (SU) and multi-user (MU) transmission scenarios of network devices.

[0158] In 802.11ax, in scenarios where network devices perform single-user (SU) transmissions, the PPDU transmitted by the network device is a HE SU PPDU. Figure 4A shows a schematic diagram of the structure of an 802.11ax HE SU PPDU. The HE SU PPDU includes 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), an efficient signaling field A (HE-SIG A), an efficient segment training field (HE-STF), an efficient long training field (HE-LTF), a data field, and a packet extension (PE). The L-SIG and RL-SIG have the same length, and the duration of the field following the L-SIG is not an integer multiple of 3.

[0159] In 802.11ax, in scenarios where network devices perform multi-user (MU) transmissions, the PPDU transmitted by the network devices is the HE MU PPDU. Figure 4B shows a schematic diagram of the structure of an 802.11ax HE MU PPDU. The HE MU PPDU includes L-STF, L-LTF, L-SIG, RL-SIG, HE-SIG A, HE-SIG B, HE-STF, HE-LTF, a data field, and PE. L-SIG and RL-SIG have the same length, and the duration of the field following L-SIG in L-SIG is not an integer multiple of 3.

[0160] In 802.11ax, a HE NDP was designed for HE PPDU. Figure 4C shows a schematic diagram of the 802.11ax HE NDP structure. The HE NDP includes L-STF, L-LTF, L-SIG, RL-SIG, HE-SIG A, HE-STF, HE-LTF, and PE.

[0161] PPDUs are divided into NDPs and PPDUs containing data fields. NDPs are PPDUs that do not contain data fields and can be understood as a special type of PPDU.

[0162] When Bfee receives an NDP, it first determines the version of the received PPDU based on L-SIG and RL-SIG, and then determines that the received PPDU is an NDP by calculating that the symbol count of the data field is 0.

[0163] Specifically, Bfee detects L-SIG and RL-SIG. If these two fields are the same, and the duration of the field following L-SIG is not a multiple of 3, then the received signal is confirmed as an HE PPDU. L-SIG includes length indication information, indicating the sum of the durations of all fields following L-SIG. The lengths of HE-SIG-A and HE-STF are fixed. Bfee can calculate that the length of the data field is 0 based on the lengths of HE-SIG-A and HE-STF, the number of HE-LTFs indicated by HE-SIG-A, the length of the guard interval, the size of the HE-LTF, and packet extension-related parameters, thus determining that the received HE PPDU is an HE NDP.

[0164] Regarding the 802.11be standard under discussion, related technologies provide a structure for an EHT PPDU containing a data field, corresponding to 802.11be. Figure 5 illustrates a possible structure of an EHT PPDU. The EHT PPDU includes L-STF, L-LTF, L-SIG, RL-SIG, U-SIG, EHT-SIG, EHT-STF, EHT-LTF, a data field, and PE. L-SIG and RL-SIG have the same length, and the duration of the field following L-SIG is a multiple of 3.

[0165] U-SIG and EHT-SIG are signaling fields. U-SIG carries common information such as PPDU version information, uplink / downlink information, PPDU frequency bandwidth information, and puncturing indication information. EHT-SIG includes information indicating resource allocation and data demodulation.

[0166] As shown in Table 1, Table 1 illustrates one possible structure of U-SIG in an EHT PPDU containing data fields. The U-SIG includes the following subfields: Physical Layer Version Identifier, Uplink / Downlink (UL / DL) Identifier, Basic Service Set Color (BSS Color), Transmit Opportunity (TXOP), Bandwidth and Preamble Puncture Identifier, PPDU Format, Space-Time Block Code (STBC), Spatial Reuse, Guard Interval (GI) and EHT-LTF Size, Low-Density Parity Check Extra Symbol Segment (LDPC Extra Symbol Segment), Pre-FEC Padding Factor, Packet Extension Disambiguity (PE Disambiguity), and the number of EHT-SIG symbols or MU-MIMO users. The symbols or MU-MIMO users) subfield, the EHT-SIG modulation and coding scheme (MCS) and dual coding modulation (DCM) subfield, the cyclic redundancy code (CRC) and the tail bit.

[0167] Table 1

[0168]

[0169]

[0170] The Physical Layer Version Indicator (PLDU) subfield indicates the generation of the PPDU. The Uplink / Downlink Indicator subfield indicates whether it's uplink or downlink. The BSS Color subfield indicates the color of the BSS where the PBr resides. The Bandwidth and Preamble Puncture Indicator subfield indicates the bandwidth and preamble puncture information of the data packet. The PPDU Format subfield indicates the format of the PPDU. The STBC subfield indicates whether STBC is used in the data portion. The Symbol Portion other than Low-Density Parity Check (LDPC) subfield indicates whether an additional symbol portion is transmitted after LDPC encoding. The Forward Error Control Prepuppet Factor subfield indicates the prepuppet factor before forward error control. The Data Packet Extension Ambiguity subfield indicates whether there is ambiguity in the data packet extension. The EHT-SIG Symbol Count or MU-MIMO User Count subfield indicates the EHT-SIG symbol count or the number of users transmitting in MU-MIMO. The EHT-SIG MCS and DCM subfields indicate the EHT-SIG MCS and whether DCM is used. CRC is used for information verification. The Trailing Bits are used for end encoding.

[0171] Table 2 illustrates a possible structure of the EHT-SIG in an EHT PPDU containing data fields. The EHT-SIG in an EHT PPDU includes the number of EHT-LTF symbols, intermediate preamble periodicity and doppler subfields, preamble puncture indicator subfield, cyclic redundancy check (CRC) code, tail bits, station identification information subfield, number of space-time streams (NSTS) subfield, coding subfield, modulation and coding scheme (MCS) subfield, beam change subfield, beamformed subfield, CRC, and tail bits. The number of bits in each subfield in Table 2 represents the number of information bits before encoding.

[0172] Table 2

[0173]

[0174]

[0175] The EHT-LTF symbol count, intermediate preamble period, and Doppler subfields indicate the symbol count, intermediate preamble period, and Doppler level of the EHT-LTF. These subfields can be understood as indicating the symbol count of the EHT-LTF. The preamble puncture indicator subfield indicates the preamble puncture mode. The site identification information subfield indicates the association identifier (AID). The encoding subfield indicates the encoding method used. The modulation and coding strategy subfield indicates the modulation and coding strategy of the data portion. The beamforming subfield indicates whether beamforming is applied. The beamforming subfield indicates whether beamforming is used.

[0176] It should be understood that the EHT-SIG in the EHT PPDU includes common fields and user-specific fields. User-specific fields include one or more user fields. Among them, the symbol number, intermediate preamble period, and Doppler subfield of the EHT-LTF corresponding to bits B0-B21, the preamble puncture indicator subfield, cyclic redundancy code, and tail bits are common fields. The site identification information subfield, space-time stream number subfield, coding subfield, modulation and coding strategy subfield, beamforming subfield, CRC, and tail bits corresponding to bits B22 and thereafter are user-specific fields.

[0177] The site identification information subfield, space-time stream number subfield, encoding subfield, modulation and coding strategy subfield, beamforming subfield, and beamforming subfield are grouped into a set of user fields. User fields are typically grouped in pairs, with a CRC and tail field following each pair of user fields. If the number of user fields is odd, the last user field is grouped separately, and this last user field is followed by a CRC and tail field.

[0178] As can be seen from Table 2, the number of user fields is 1, in which case the number of EHT-SIG symbols is the smallest. Using BPSK at a 1 / 2 code rate, the encoded EHT-SIG symbol count is 2 symbols. Therefore, it can be assumed that in an EHT PPDU containing data fields, the number of EHT-SIG symbols is greater than or equal to 2.

[0179] However, regarding the 802.11be standard under discussion, 802.11be only provides the structure of an EHT PPDU containing a data field, as shown in Figure 5, and does not cover the structure of an EHT PPDU without a data field, that is, it does not provide an EHT NDP that meets the 802.11be standard. Therefore, APs and STAs cannot perform NDP measurements to obtain channel state information.

[0180] Based on the above background, this application provides some NDP structures for standards after 802.11ax. Thus, in scenarios where wireless communication is performed using standards after 802.11ax (e.g., 802.11be), Bfee can perform channel estimation based on the NDP to provide feedback beamforming reports.

[0181] The following describes the structure of NDP provided by the technical solution of this application, using the PPDU transmission method provided in the embodiments of this application as an example.

[0182] Please refer to Figure 6, which is a flowchart illustrating a PPDU transmission method according to an embodiment of this application. The method may include the following steps:

[0183] 602. Bfer generates PPDU;

[0184] This PPDU is an NDP for standards after 802.11ax and does not contain a data field. This NDP is used for channel sounding with Bfee. Channel sounding in this application can also be referred to as channel measurement or channel estimation.

[0185] The NDP can be any one of several NDPs for standards after 802.11ax that can be provided in the following embodiments of this application.

[0186] The first type of NDP provided in this application includes a subfield indicating that the PPDU is an NDP. This allows the Bfee receiving the NDP to identify it earlier, improving the efficiency of Bfee reading the NDP.

[0187] The second type of NDP provided in this application includes an EHT-SIG, wherein the EHT-SIG has 1 symbol and uses BPSK modulation with a 1 / 2 code rate. Thus, compared to the EHT-SIG in the PPDU containing a data field shown in Table 2, it has fewer symbols, thereby saving the overhead required for transmitting the NDP.

[0188] The third type of NDP provided in this application includes an AID subfield for indicating information related to the user of the NDP. Thus, the Bfee receiving the NDP can determine the relevant information of the NDP user based on the AID in the NDP's EHT-SIG, thereby accurately determining whether it is a user that needs to perform channel sensing and provide beamforming reports.

[0189] It should be understood that the names of the relevant fields in the NDP provided in the embodiments of this application (such as EHT-STF, SHT-LTF, EHT-SIG, etc.) are determined according to the 802.11be standard after 802.11ax. The names of the relevant fields in the NDP provided in the embodiments of this application can also be replaced with the names of fields related to standards after 802.11ax. In the embodiments of this application, the NDP includes multiple subfields, and the embodiments of this application do not limit the naming of the various subfields; in other embodiments, they can also be replaced with other names.

[0190] 604. Bfer sends PPDU;

[0191] Correspondingly, Bfee receives PPDUs.

[0192] 606. Bfee uses NDP to perform channel estimation and obtain channel state information;

[0193] Optionally, after obtaining the channel state information, the method may further include step 608, whereby Bfee may send a beamforming report containing the channel state information to Bfer.

[0194] Thus, in scenarios where wireless communication is conducted using standards after 802.11ax (e.g., 802.11be), Bfee can perform channel estimation based on the NDP, obtain channel state information, and feed back beamforming reports to Bfee.

[0195] In this embodiment, Bfer can be either AP or STA. Bfee can be either STA or AP.

[0196] Optionally, before step 602, the following steps are also included:

[0197] 601. Bfee sends an NDPA frame. The NDPA frame may include a site information field, which includes an AID subfield indicating the AID of the site that needs to perform channel sounding and report beamforming. In this way, Bfee can determine whether it needs to obtain channel state information based on the AID subfield in the NDPA frame. If so, Bfee can obtain channel state information within the frequency range corresponding to the partial bandwidth information indicated in the NDPA frame via NDPA.

[0198] The following section details the specific structures and corresponding technical effects of several NDPs used in standards after 802.11ax involved in the above method steps.

[0199] In some possible implementations, the NDP transmitted in the PPDU transmission method of this application embodiment adopts the structure of the first NDP provided in this application embodiment.

[0200] The first type of NDP provided in this application includes a U-SIG; the U-SIG includes a subfield indicating that the PPDU is an NDP. The Bfee receiving this NDP can determine that the PPDU is an NDP subfield based on the subfield indicating that the PPDU is an NDP in the U-SIG. This allows the Bfee to prepare the process for calculating channel state information in advance, gaining more processing time, instead of needing to confirm that the PPDU is an NDP subfield after calculating that the length of the data portion of the PPDU is 0. Such an NDP helps improve the efficiency of Bfee receiving NDPs.

[0201] The U-SIG may include at least one of the following: an NDP indicator subfield, a PPDU format subfield, or a subfield indicating the number of EHT-SIG symbols. The subfield indicating that the PPDU is NDP is an NDP indicator subfield, a PPDU format subfield, or a subfield indicating the number of EHT-SIG symbols in the U-SIG.

[0202] Specifically, in some embodiments, U-SIG includes an NDP indicator subfield, a PPDU format subfield, or a subfield indicating the number of EHT-SIG symbols. Any one of the NDP indicator subfield, PPDU format subfield, or subfield indicating the number of EHT-SIG symbols is a subfield indicating that the PPDU is NDP.

[0203] In other embodiments, U-SIG includes an NDP indicator subfield and a PPDU format subfield, where either the NDP indicator subfield or the PPDU format subfield is a subfield indicating that the PPDU is NDP; or U-SIG includes a PPDU format subfield and a subfield indicating the number of EHT-SIG symbols, where either the PPDU format subfield or the subfield indicating the number of EHT-SIG symbols is a subfield indicating that the PPDU is NDP; or U-SIG includes an NDP indicator subfield and a subfield indicating the number of EHT-SIG symbols, where either the NDP indicator subfield or the subfield indicating the number of EHT-SIG symbols is a subfield indicating that the PPDU is NDP.

[0204] In some other embodiments, U-SIG includes an NDP indicator subfield, which is a subfield indicating that the PPDU is NDP; or U-SIG includes a PPDU format subfield, which is a subfield indicating that the PPDU is NDP; or U-SIG includes a subfield indicating the number of EHT-SIG symbols, which is a subfield indicating that the PPDU is NDP.

[0205] The subfield indicating the number of EHT-SIG symbols can be, for example, but not limited to, the EHT-SIG symbol count or MU-MIMO user count subfield, or the EHT-SIG symbol count subfield used only to indicate the number of EHT-SIG symbols.

[0206] The subfield indicating the EHT-SIG symbol count can, for example, indicate that the EHT-SIG symbol count is a certain set value to indicate that the PPDU is an NDP. For example, the subfield indicating the EHT-SIG symbol count can indicate that the EHT-SIG symbol count is 0, indicating that the PPDU is an NDP.

[0207] In related technologies, Figure 7 shows a schematic diagram of the PPDU structure transmitted on each channel in a scenario of aggregated PPDU transmission. Four channels with different frequency domains transmit HE MU PPDUs containing data fields and three EHT PPDUs containing data fields, respectively. The HE MU PPDUs containing data fields do not contain U-SIG and EHT-SIG, but they do contain HE-SIG A and HE-SIG B. HE-SIG A and HE-SIG B are positioned in the same place and have the same number of symbols as U-SIG and EHT-SIG in the EHT PPDUs containing data fields. This ensures symbol alignment of the PPDUs transmitted on each channel, avoiding out-of-band interference between different frequency bands.

[0208] However, HE NDP only contains HE-SIG A (two symbols) and does not include HE-SIG B. If the corresponding EHT NDP is designed according to the format of EHT PPDU with data field shown in Figure 5, the EHT NDP will include EHT-SIG. As shown in the aggregated PPDU structure in Figure 8, if EHT NDP and HE NDP designed according to the format of EHT PPDU with data field shown in Figure 5 are transmitted together in the aggregated PPDU structure, it will cause the symbols of the PPDU transmitted on each channel to be misaligned, resulting in out-of-band interference between different frequency bands.

[0209] Figure 9 shows a schematic diagram of the NDP structure of an embodiment of this application. In the first type of NDP provided in this application, the NDP also includes an EHT-STF adjacent to and following U-SIG. The EHT-STF immediately follows U-SIG. This NDP does not contain EHT-SIG. In this way, the EHT NDP adopts the structure of the first type of NDP of this application, which helps to achieve alignment with HE NDP symbols.

[0210] Optionally, the first type of NDP in this application may also include L-STF, L-LTF, L-SIG, RL-SIG, EHT-STF, EHT-LTF and PE.

[0211] L-STF, L-LTF, and L-SIG are used to ensure the coexistence of new and legacy equipment. L-SIG includes a length indicator field that indicates the number of symbols in subsequent fields. RL-SIG enhances the reliability of legacy signaling fields. EHT-STF is used for automatic gain control of subsequent fields. EHT-LTF is used for channel estimation.

[0212] L-SIG and RL-SIG are identical, and the length field in L-SIG indicates that the duration of the field following L-SIG is a multiple of 3. Thus, Bfee can identify a PPDU as an EHT or later version PPDU by detecting L-SIG and RL-SIG, and by recognizing that the duration of the field following L-SIG in the length field of L-SIG is a multiple of 3. It can then further identify the specific version of the PPDU based on the physical layer version indication in U-SIG.

[0213] As shown in Figure 10, when EHT NDP and HE NDP, which adopt the NDP structure shown in Figure 9, are transmitted together in the aggregated PPDU structure, alignment between HE NDP symbols can be achieved, thus avoiding out-of-band interference between different frequency bands.

[0214] As shown in Figure 9, the first type of NDP in this application does not include EHT-SIG. U-SIG may not indicate the number of EHT-SIG symbols and MCS, nor does it need to indicate encoding-related indicators, such as the LDPC extra symbol fragmentation indicator. The data packet extension indicator can use a fixed value, and therefore does not need to be indicated. Thus, U-SIG may not contain the subfield indicating the number of EHT-SIG symbols, the MCS subfield, the subfield representing the symbol portion other than the low-density parity check code, and the data packet extension ambiguity subfield. The bits used to carry these fields in the U-SIG of the PPDU containing data fields can be used to carry other information in the U-SIG of the NDP, or in other words, the bits carrying these fields can be used to carry other fields. For example, the bits carrying these fields can be used to carry the subfield indicating the number of EHT-LTF symbols, thus allowing the U-SIG of the NDP to include more information.

[0215] It should be understood that in some alternative embodiments, based on the structure of the NDP shown in FIG9, the U-SIG may also include a subfield indicating the number of EHT-SIG symbols. The subfield indicating the number of EHT-SIG symbols indicates that the number of EHT-SIG symbols is a certain set value to indicate that the PPDU is an NDP.

[0216] Optionally, U-SIG also includes at least one of a number of spatial streams (NSS) subfield and a subfield indicating the number of EHT-LTF symbols, wherein the NSS subfield and / or the subfield indicating the number of EHT-LTF symbols indicates both the NSS and the number of EHT-LTF symbols. The subfield indicating the number of EHT-LTF symbols may be, for example, the number of EHT-LTF symbols, an intermediate preamble, and a Doppler subfield, or it may be a separate EHT-LTF symbol number subfield.

[0217] There is a correspondence between NSTS and NSS. When using space-time block coding (STBC), the number of streams in NSTS is twice that in NSS, expressed as NSTS = 2 * NSS. When not using STBC, the number of streams in NSTS is the same as that in NSS, expressed as NSTS = NSS. Thus, the NSS subfield that indicates NSS can also indicate NSTS. The NSS subfield can be interchanged with NSTS.

[0218] There is a correspondence between the number of symbols in EHT-LTF and the number of symbols in NSTS. For example, an NSTS of 1 corresponds to 1 EHT-LTF symbol; an NSTS of 2 corresponds to 2 EHT-LTF symbols; an NSTS of 3 or 4 corresponds to 4 EHT-LTF symbols; an NSTS of 5 or 6 corresponds to 6 EHT-LTF symbols; an NSTS of 7 or 8 corresponds to 8 EHT-LTF symbols; an NSTS of any one of 9-12 corresponds to 12 EHT-LTF symbols; and an NSTS of any one of 13-16 corresponds to 16 EHT-LTF symbols.

[0219] Specifically, in one embodiment, U-SIG includes an NSTS subfield and a subfield indicating the EHT-LTF symbol count. The NSTS subfield indicates the NSTS, and the subfield indicating the EHT-LTF symbol count indicates the EHT-LTF symbol count. Alternatively, U-SIG includes an NSS subfield and a subfield indicating the EHT-LTF symbol count, where the NSS subfield indicates the NSS and, based on the aforementioned correspondence between NSTS and NSS, indicates the NSTS. The subfield indicating the EHT-LTF symbol count indicates the EHT-LTF symbol count.

[0220] In another embodiment, U-SIG includes an NSTS subfield but does not include a subfield indicating the number of EHT-LTF symbols or an NSS subfield. The NSTS subfield indicates NSTS and, based on the two correspondences described above, can indirectly indicate the NSS and the number of EHT-LTF symbols. Alternatively, U-SIG includes an NSS subfield but does not include a subfield indicating the number of EHT-LTF symbols or an NSTS subfield; the NSS subfield indicates NSS and, based on the two correspondences described above, can indirectly indicate the NSTS and the number of EHT-LTF symbols.

[0221] In yet another embodiment, U-SIG includes a subfield indicating the number of EHT-LTF symbols, but does not include an NSTS subfield and an NSS subfield. The subfield indicating the number of EHT-LTF symbols indicates the number of EHT-LTF symbols, and indicates at least one of NSS and NSTS based on the above correspondence.

[0222] In an optional embodiment, the contents of the U-SIG of the first type of NDP in this application are shown in Table 3. Specifically, the U-SIG includes a physical layer version identifier subfield, an uplink / downlink (UL / DL) indicator subfield, a basic service set color (BSS color) subfield, a transmit opportunity (TXOP) subfield, a bandwidth indicator subfield, a PPDU format subfield, an NDP indicator subfield, a spatial reuse indicator subfield, a guard interval (GI) and EHT-LTF size indicator subfield, the number of EHT-LTF symbols, the intermediate preamble period and Doppler subfield, the number of spatial streams (NSS) subfield, CRC, and a tail bit. The U-SIG also includes 5 bits as reserved bits for carrying other information that needs to be carried. It should be understood that, based on the above correspondence between NSTS and NSS, the NSS subfield in Table 4 can be replaced with the NSTS subfield.

[0223] Table 3

[0224]

[0225]

[0226] The NDP indicator subfield indicates that the PPDU is an NDP. The contents of the other subfields in this U-SIG can be found in the descriptions of their corresponding subfields in Tables 1 and 2, and will not be detailed here.

[0227] It should be understood that the embodiments of this application do not limit the order of the various subfields in Table 3 and the number of bits they occupy. In other embodiments, adjustments can be made according to the actual situation.

[0228] In some other possible implementations, the NDP transmitted in the PPDU transmission method of this application embodiment adopts the structure of the second NDP provided in this application embodiment.

[0229] The second type of NDP provided in this application includes EHT-SIG. The EHT-SIG has one symbol and uses BPSK, 1 / 2 code rate modulation. Thus, compared to the EHT-SIG in the PPDU containing a data portion shown in Table 2, the structure of the second type of NDP provided in this application reduces the number of EHT-SIG symbols, thereby saving the overhead required for transmitting the NDP.

[0230] Optionally, as shown in the structural diagram of the NDP in Figure 11, the second type of NDP provided in this application embodiment may further include L-STF, L-LTF, L-SIG, RL-SIG, U-SIG, EHT-STF, EHT-LTF, and PE. The PE is used to help Bfee gain more processing time. The NDP may also exclude the PE. For example, if Bfee has strong processing capabilities, the NDP may not include the PE.

[0231] For descriptions of L-STF, L-LTF, L-SIG, RL-SIG, EHT-STF, and EHT-LTF, as well as the description of Bfee's identification of PPDUs, please refer to the relevant descriptions of the implementation of the first type of NDP structure mentioned above, which will not be elaborated here.

[0232] Based on the second type of NDP structure provided in the embodiments of this application, the embodiments of this application provide some indication methods for indicating that the PPDU is an NDP, and related technologies for how Bfee can know that it is an NDP based on the indication.

[0233] In one indication method where the PPDU is an NDP, the U-SIG in the NDP includes a subfield indicating the EHT-SIG symbol count, which indicates that the EHT-SIG symbol count is any value greater than or equal to 1. This subfield indicating the EHT-SIG symbol count can be, for example, an EHT-SIG symbol count or a MU-MIMO user count indication subfield, or simply an EHT-SIG symbol count subfield.

[0234] Optionally, Bfee can obtain the sum of the lengths of all fields following L-SIG based on the length indication information in L-SIG. Then, based on the number of EHT-SIG symbols, the number of EHT-LTFs, the length of the guard interval, the size of the EHT-LTF, and packet extension-related parameters indicated in U-SIG and EHT-SIG, it can obtain the lengths of RL-SIG, EHT-SIG, EHT-LTF, and PE. The lengths of RL-SIG, U-SIG, and EHT-STF are fixed. Therefore, Bfee can subtract the lengths of RL-SIG, U-SIG, EHT-SIG, EHT-STF, EHT-LTF, and PE from the lengths of all fields following L-SIG obtained from the length indication information in L-SIG to obtain the length of the data field and calculate the number of symbols in the data field. If Bfee calculates that the length of the data field is less than or equal to 0, it identifies the PPDU as an NDP.

[0235] It can be understood that if the subfield indicating the EHT-SIG symbol count is 1, Bfee can calculate that the length of the data field in the PPDU is 0, thus determining that the PPDU is an NDP. If the subfield indicating the EHT-SIG symbol count is greater than 1, Bfee can calculate that the length of the data field in the PPDU is less than 0, thus determining that the PPDU is an NDP.

[0236] Furthermore, the subfield indicating the EHT-SIG symbol count shows that the EHT-SIG symbol count is 1. The U-SIG also includes an MCS subfield, which indicates that the EHT-SIG uses BPSK, 1 / 2 code rate modulation. As shown in Table 2, in the PPDU containing the data field, the EHT-SIG information bits are 54 bits. Under BPSK, 1 / 2 code rate modulation, the encoded EHT-SIG symbol count is greater than 1.

[0237] In this way, Bfee can determine that the PPDU is an NDP based on the subfield indicating the number of symbols in EHT-SIG as 1 and the MCS subfield indicating that EHT-SIG is BPSK, 1 / 2 code rate modulation. Bfee can identify the PPDU as an NDP without calculating the number of symbols in the data field. This allows Bfee to prepare the channel state information calculation process in advance, gaining more processing time, instead of needing to confirm the NDP subfield after calculating the length of the PPDU's data portion as 0. This improved NDP reading efficiency for Bfee.

[0238] In an optional embodiment, U-SIG further includes an NDP indicator subfield and / or a PPDU format subfield. The NDP indicator subfield or PPDU format subfield in U-SIG indicates that the PPDU is in uncompressed mode. In the case of uncompressed mode, the EHT-SIG symbol count or MU-MIMO user count indicator subfield in U-SIG indicates the EHT-SIG symbol count. This enables the EHT-SIG symbol count or MU-MIMO user count indicator subfield to indicate that the EHT-SIG symbol count is 1.

[0239] It should be understood that, in another alternative embodiment, when the PPDU is in compressed mode or uncompressed mode, the EHT-SIG symbol count subfield in U-SIG indicates that the symbol count of EHT-SIG is 1.

[0240] In another alternative embodiment, the EHT-SIG of the NDP includes public fields but excludes user-specific fields. This reduces the number of symbols in the EHT-SIG by omitting user fields.

[0241] Specifically, as shown in Table 4, the EHT-SIG of this NDP includes the number of EHT-LTF symbols, the intermediate preamble period and Doppler subfield, the preamble puncture indicator subfield, the number of space-time streams (NSTS) subfield, the cyclic redundancy code (CRC), and the tail bit. The number of EHT-LTF symbols, the intermediate preamble period, and the Doppler subfield can be understood as subfields indicating the number of EHT-LTF symbols. It should be understood that, based on the above correspondence between NSTS and NSS, the NSTS subfield in Table 4 can be replaced with the NSS subfield.

[0242] Table 4

[0243]

[0244] The EHT-LTF symbol count, intermediate preamble period, and Doppler indicate the EHT-LTF symbol count, intermediate preamble period, and Doppler. The preamble puncture indicator subfield indicates the preamble puncture mode. The NSTS subfield indicates the space-time stream count or spatial stream count of a STA. Optionally, if space-time block coding is not considered, the NSTS subfield indicates the NSS, or the NSTS subfield in Table 4 can be replaced with the NSS subfield. CRC is used for information verification. The tail bit is used to end the encoding.

[0245] Optionally, the EHT-SIG may include only one of the following subfields: the NSTS subfield, the Number of Spatial Streams (NSS) subfield (indicating the number of spatial streams), the EHT-LTF symbol number, the intermediate preamble period, and the Doppler subfield. This eliminates some fields in the EHT-SIG, and the bits originally used to carry these omitted fields can be used to carry other information.

[0246] In one possible scenario, the EHT-SIG includes the EHT-LTF symbol number, intermediate preamble period, and Doppler subfield, but excludes the NSTS and NSS subfields. In this case, the bits (B12-B15) originally intended to carry the NSTS or NSS subfields can be used to carry other information.

[0247] Specifically, the portion of the EHT-LTF's symbol count, intermediate preamble period, and Doppler subfield that originally indicated the EHT-LTF's symbol count can be used to indicate the EHT-LTF's symbol count or to escape and indicate the NSTS. Based on the correspondence between the EHT-LTF's symbol count and NSTS, and the correspondence between NSS and NSTS in the above description of the first type of NDP, the EHT-LTF's symbol count, intermediate preamble period, and Doppler subfield can indicate either the EHT-LTF's symbol count, NSTS, or NSS, thus indicating both the EHT-LTF's symbol count and NSTS, or vice versa.

[0248] In another possible scenario, EHT-SIG includes the NSTS subfield but excludes the NSS subfield, the EHT-LTF symbol count, the intermediate preamble period, and the Doppler subfield. Specifically, the NSTS subfield indicates the NSTS and, based on the correspondence between the EHT-LTF symbol count and NSTS, and the correspondence between NSS and NSTS in the relevant description of the first type of NDP, indirectly indicates the NSS and the EHT-LTF symbol count. Thus, the bits (B0-B3) originally used to carry the EHT-LTF symbol count, the intermediate preamble period, and the Doppler subfield can be used to carry other information.

[0249] In another possible scenario, EHT-SIG includes the NSS subfield but excludes the NSTS subfield, the EHT-LTF symbol count, the intermediate preamble period, and the Doppler subfield. The NSS subfield indicates the NSS and, based on the correspondence between the EHT-LTF symbol count and NSTS, and the correspondence between NSS and NSTS in the relevant description of the first type of NDP, indirectly indicates the NSTS and the EHT-LTF symbol count. Thus, the bits (B0-B3) originally used to carry the EHT-LTF symbol count, the intermediate preamble period, and the Doppler subfield can be used to carry other information.

[0250] It should be understood that in the second type of NDP provided in this application, the two optional embodiments described above can be implemented individually or in combination.

[0251] As can be seen, in the second type of NDP provided in this application embodiment, there is only one EHT-SIG symbol, which reduces the overhead of NDP while carrying sufficient information.

[0252] In some other possible implementations, the NDP transmitted in the PPDU transmission method of this application embodiment adopts the third NDP structure provided in this application embodiment.

[0253] The third type of NDP provided in this application includes EHT-SIG. EHT-SIG includes a user field. This user field includes an AID subfield indicating the AID. Specifically, the EHT-SIG in the NDP includes a public field and a user-specific field. The public field indicates some public information, such as preamble indication information, indicating the punching status of the EHT NDP. The user-specific field includes this user field.

[0254] In one possible implementation, the AID is used to indicate information related to the user of the NDP. The NDP user can be one or more STAs or an AP. Thus, Bfee can determine the relevant information of the NDP user based on the AID in the NDP's EHT-SIG. This allows it to accurately determine whether it is a user that needs to perform channel sensing and report beamforming.

[0255] Below are some examples of AID subfields indicating information related to the user of the NDP.

[0256] In some embodiments, the user of the NDP is a single station, and the AID subfield indicates the AID of that station. It is understood that in such embodiments, only one station receives the NDP, performs channel estimation, and feeds back a beamforming report.

[0257] In this way, the station corresponding to the AID can determine itself as a station that needs to perform channel probing and report beamforming based on the channel probing results, according to the AID in the NDP. Thus, even if the station fails to read the user field containing its own AID due to incorrect reading of the NDPA frame, it can still determine itself as a station that needs to perform channel probing and report beamforming based on the channel probing results, thereby improving the success rate of beamforming report acquisition by the Bfer. Furthermore, devices whose AID does not match the AID indicated by the AID subfield will not continue receiving the NDP after receiving it, as the AID indicated by the AID subfield does not match their own AID. This saves power consumption for devices whose AID does not match the AID indicated by the AID subfield.

[0258] In other embodiments, the users of the NDP are multiple stations, and the AID indicated by the user field is 0, indicating that the NDP is sent in a broadcast manner. In such embodiments, the EHT-SIG of the NDPA frame sent before the NDP includes multiple station fields, and the AID subfield of the multiple station fields indicates the AID of the station that needs to perform channel sensing and feed back beamforming reports. Thus, when a station receives the NDP, it determines that the users of the NDP are multiple stations based on the fact that the AID subfield in the NDP is 0.

[0259] In this way, all stations that receive the NDP, or the stations corresponding to the AID indicated by the user field in the NDPA frame, continue to receive the NDP in order to obtain channel state information based on the NDP and feed back beamforming reports.

[0260] In some other embodiments, the NDP user is the access point, and the AID subfield indicates a set value for the AID. This set value can be broadcast by the AP or it can be a standard, predetermined fixed value, such as 2045. It should be understood that this set value can also be other values.

[0261] Optionally, the structure of the third type of NDP provided in this application embodiment can be referred to Figure 11. The NDP also includes L-STF, L-LTF, L-SIG, RL-SIG, U-SIG, EHT-STF, EHT-LTF, and PE. The functions of these sub-fields can be referred to the relevant descriptions in the first type of NDP provided in the above application embodiment, and will not be detailed here.

[0262] As can be seen, this NDP structure is similar to the format of the EHT PPDU containing a data field shown in Figure 5. This allows Bfee to receive the NDP using a similar receiving strategy as the EHT PPDU containing a data field, making it easier for Bfee to receive the NDP.

[0263] Regarding the method by which Bfee identifies the version of the PPDU, please refer to the description of Bfee identifying the version of the PPDU in the embodiment corresponding to the first NDP provided in the above-mentioned embodiments of this application, which will not be described in detail here.

[0264] Regarding the method by which Bfee identifies a PPDU as an NDP, the second NDP-corresponding embodiment provided in the above-described embodiments of this application can be used, in which Bfee calculates the length of the data field and calculates that the length of the data field is 0, thereby identifying the PPDU as an NDP.

[0265] In the third type of NDP provided in this application embodiment, some simpler indication methods can also be used to indicate that the PPDU is an NDP. This allows Bfee to determine that the PPDU is an NDP in a simpler way and earlier, prepare the process for calculating channel state information in advance, and obtain more processing time.

[0266] In one indication method for identifying a PPDU as an NDP, the U-SIG includes a format subfield and / or a compression subfield. The format or compression subfield in the U-SIG indicates that the PPDU is an NDP. This allows Bfee to identify the PPDU as an NDP based on the format or compression subfield after recognizing it. This enables the identification of the PPDU as an NDP before calculating the symbol count of the data field in the PPDU to be 0, and allows the PPDU to be read according to the NDP format. This allows Bfee to prepare the channel state information calculation process in advance, gaining more processing time and improving the efficiency of NDP reading.

[0267] Such a method of indicating that the PPDU is an NDP can be implemented in combination with any of the embodiments described above that indicate user information related to the NDP in the AID subfield, or it can be implemented alone.

[0268] Specifically, in one embodiment, U-SIG includes a format subfield and a compression subfield, wherein the format subfield or the compression subfield indicates that the PPDU is an NDP. In another embodiment, U-SIG includes a format subfield that indicates that the PPDU is an NDP. In yet another embodiment, U-SIG includes a compression subfield that indicates that the PPDU is an NDP.

[0269] Of course, in other embodiments, the format subfield or compression subfield may also indicate that the PPDU is a compressed PPDU. In such embodiments, the PPDU is a compressed NDP, which can reduce the overhead of EHT-SIG in the NDP.

[0270] In another method of indicating that the PPDU is an NDP, the AID in the EHT-SIG indicates that the PPDU is an NDP. Specifically, the AID in the EHT-SIG is a set value indicating that the PPDU is an NDP. This value indicating that the PPDU is an NDP can be, for example, 2044. Of course, in other embodiments, this value indicating that the PPDU is an NDP can also be other values.

[0271] In one optional embodiment, the number of EHT-LTFs is greater than the number of space-time streams. Thus, in scenarios involving the transmission of aggregated PPDU structures, when multiple NDPs with the same structure as the third type of NDP are transmitted on different channels, even if the space streams on each channel are different, the number of symbols in the EHT-LTFs of each NDP transmitted on each channel can be the same. This helps to align the symbols of each field of each NDP, thereby avoiding out-of-band interference between different frequency bands.

[0272] In the embodiments provided above, the methods provided by the embodiments of this application have been described from the perspectives of access points and sites. To implement the functions of the methods provided in the embodiments of this application, access points and sites may include hardware structures and software modules, and may implement the above functions in the form of hardware structures, software modules, or a combination of hardware structures and software modules. One of the above functions may be executed in the form of hardware structures, software modules, or a combination of hardware structures and software modules.

[0273] Please refer to Figure 12, which is a schematic diagram of the modules of the transmission device provided in the embodiment of this application. The transmission device 1200 includes a processing unit 1201 and a sending unit 1202.

[0274] Processing unit 1201 is used to generate PPDU, the PPDU including a general signaling field U-SIG; the U-SIG includes a subfield indicating that the PPDU is an empty data packet NDP;

[0275] The transmitting unit 1202 is used to transmit the PPDU.

[0276] In this way, the Bfee receiving the NDP can determine that the PPDU is an NDP subfield based on the subfield indicating that the PPDU is an NDP in the U-SIG. This allows the Bfee to prepare the channel state information calculation process in advance, gaining more processing time, instead of having to confirm that the PPDU is an NDP subfield after calculating that the length of the PPDU's data portion is 0. This improved NDP reception efficiency for the Bfee.

[0277] The transmission device 1200 can be understood as a Bfer. The transmission device 1200 can be, for example, an access point or a site. Or the transmission device is deployed at an access point or site. The processing unit 1201 of the transmission device 1200 can be a processor, and the transmitting unit 1202 of the transmission device 1200 can be a transceiver.

[0278] In some embodiments, the PPDU also includes an extremely high throughput short training field, EHT-STF, which is adjacent to and follows the U-SIG.

[0279] In some embodiments, the subfield indicating that the PPDU is an NDP is an NDP indicator subfield, a PPDU format subfield, or a subfield indicating the number of EHT-SIG symbols in the U-SIG.

[0280] In some embodiments, the U-SIG further includes a spatial stream count subfield and / or a subfield indicating the number of EHT-LTF symbols in the ultra-high throughput long training field, wherein the spatial stream count subfield and / or the subfield indicating the number of EHT-LTF symbols indicates the number of space-time streams and the number of EHT-LTF symbols.

[0281] Please refer to Figure 13, which is a schematic diagram of the modules of the transmission device provided in an embodiment of this application. The transmission device 1300 includes a processing unit 1301 and a sending unit 1302.

[0282] Processing unit 1301 is used to generate PPDU, the PPDU is NDP, the PPDU includes an ultra-high throughput signaling field EHT-SIG, the EHT-SIG has 1 symbol, and the EHT-SIG uses BPSK, 1 / 2 code rate modulation;

[0283] The transmitting unit 1302 is used to transmit the PPDU.

[0284] This reduces the number of symbols in EHT-SIG, thereby saving the overhead required for transmitting NDP.

[0285] The transmission device 1300 can be understood as a Bfer. The transmission device 1300 can be, for example, an access point or a site. Or the transmission device is deployed at an access point or site. The processing unit 1301 of the transmission device 1300 can be a processor, and the transmitting unit 1302 of the transmission device 1300 can be a transceiver.

[0286] In some embodiments, the PPDU further includes a general signaling field U-SIG, which includes a subfield indicating the number of EHT-SIG symbols, wherein the subfield indicating the number of EHT-SIG symbols is any value greater than or equal to 1.

[0287] In some embodiments, the subfield indicating the number of symbols in the EHT-SIG indicates that the number of symbols in the EHT-SIG is 1, and the U-SIG further includes a coding and modulation strategy (MCS) subfield, which indicates that the EHT-SIG uses BPSK, 1 / 2 code rate modulation.

[0288] In some embodiments, the NDP indicator subfield or PPDU format subfield in the U-SIG indicates that the PPDU is in uncompressed mode.

[0289] In some embodiments, the space-time stream number subfield and / or the EHT-LTF symbol number subfield in the EHT-SIG indicate the space-time stream number and the EHT-LTF symbol number.

[0290] Please refer to Figure 14, which is a schematic diagram of the modules of the transmission device provided in an embodiment of this application. The transmission device 1400 includes a processing unit 1401 and a sending unit 1402.

[0291] Processing unit 1401 is used to generate PPDU, wherein the PPDU is an NDP, the PPDU includes EHT-SIG, the EHT-SIG includes an AID subfield indicating an associated identifier AID, and the AID is used to indicate information related to the user of the NDP;

[0292] The transmitting unit 1402 is used to transmit the PPDU.

[0293] In this way, Bfee can determine the relevant information of NDP users based on the AID in the NDP's EHT-SIG. This allows it to accurately determine whether it is a user that needs to perform channel sensing and report beamforming.

[0294] The transmission device 1400 can be understood as a Bfer. The transmission device 1400 can be, for example, an access point or a site. Or the transmission device is deployed at an access point or site. The processing unit 1401 of the transmission device 1400 can be a processor, and the transmitting unit 1402 of the transmission device 1400 can be a transceiver.

[0295] In some embodiments, the user of the NDP is a site, and the AID indicated by the AID subfield is the AID of the site.

[0296] In some embodiments, the users of the NDP are multiple sites, and the AID indicated by the user field is 0, indicating that the NDP is sent in a broadcast manner.

[0297] In some embodiments, the user of the NDP is an access point, and the AID indicated by the AID subfield is a set value.

[0298] In some embodiments, the PPDU further includes a U-SIG, which includes a format subfield and / or a compression subfield, the format subfield or the compression subfield indicating that the PPDU is an NDP.

[0299] In some embodiments, the PPDU further includes U-SIG and EHT-LTF, wherein the U-SIG includes a space-time stream number subfield indicating the space-time stream number, and the number of EHT-LTFs is greater than the space-time stream number.

[0300] Please refer to Figure 15, which is a schematic diagram of the modules of the transmission device provided in the embodiment of this application. The transmission device 1500 includes a receiving unit 1501 and a processing unit 1502.

[0301] The receiving unit 1501 is used to receive a PPDU, wherein the PPDU is an NDP, and the PPDU includes a general signaling field U-SIG; the U-SIG includes a subfield indicating that the PPDU is an empty data packet (NDP);

[0302] Processing unit 1502 is used to perform channel estimation through the NDP.

[0303] The Bfee receiving this NDP can determine that the PPDU is an NDP subfield based on the indication in the U-SIG that the PPDU is an NDP subfield. This allows the Bfee to prepare the channel state information calculation process in advance, gaining more processing time, instead of having to confirm that the PPDU is an NDP subfield after calculating that the length of the PPDU's data portion is 0. This kind of NDP helps improve the efficiency of Bfee receiving NDPs.

[0304] The transmission device 1500 can be understood as Bfee. The transmission device 1500 can be, for example, a site or access point, or the transmission device 1500 can be deployed at a site or access point. The processing unit 1502 of the transmission device 1500 can be a processor, and the receiving unit 1501 of the transmission device 1500 can be a transceiver.

[0305] In some embodiments, the PPDU also includes an extremely high throughput short training field, EHT-STF, which is adjacent to and follows the U-SIG.

[0306] In some embodiments, the subfield indicating that the PPDU is an NDP is an NDP indicator subfield, a PPDU format subfield, or a subfield indicating the number of EHT-SIG symbols in the U-SIG.

[0307] In some embodiments, the U-SIG further includes a spatial stream count subfield and / or a subfield indicating the number of EHT-LTF symbols in the ultra-high throughput long training field, wherein the spatial stream count subfield and / or the subfield indicating the number of EHT-LTF symbols indicates the number of space-time streams and the number of EHT-LTF symbols.

[0308] Please refer to Figure 16, which is a schematic diagram of the modules of the transmission device provided in an embodiment of this application. The transmission device 1600 includes a receiving unit 1601 and a processing unit 1602.

[0309] The receiving unit 1601 is used to receive PPDU, the PPDU is NDP, the PPDU includes an Extremely High Throughput Signaling Field EHT-SIG, the EHT-SIG has 1 symbol, and the EHT-SIG uses BPSK, 1 / 2 code rate modulation;

[0310] Processing unit 1602 is used to perform channel estimation through the NDP.

[0311] This reduces the number of symbols in EHT-SIG, thereby saving the overhead required for transmitting NDP.

[0312] The transmission device 1600 can be understood as Bfee. The transmission device 1600 can be, for example, a site or access point, or the transmission device 1600 can be deployed at a site or access point. The processing unit 1602 of the transmission device 1600 can be a processor, and the receiving unit 1601 of the transmission device 1600 can be a transceiver.

[0313] In some embodiments, the PPDU further includes a general signaling field U-SIG, which includes a subfield indicating the number of EHT-SIG symbols, wherein the subfield indicating the number of EHT-SIG symbols is any value greater than or equal to 1.

[0314] In some embodiments, the NDP indicator subfield or PPDU format subfield in the U-SIG indicates that the PPDU is in uncompressed mode.

[0315] In some embodiments, the subfield indicating the number of symbols in the EHT-SIG indicates that the number of symbols in the EHT-SIG is 1, and the U-SIG further includes a coding and modulation strategy (MCS) subfield, which indicates that the EHT-SIG uses BPSK, 1 / 2 code rate modulation.

[0316] In some embodiments, the space-time stream number subfield and / or the EHT-LTF symbol number subfield in the EHT-SIG indicate the space-time stream number and the EHT-LTF symbol number.

[0317] Please refer to Figure 17, which is a schematic diagram of the module of the PPDU transmission device provided in the embodiment of this application. The transmission device 1700 includes a receiving unit 1701 and a processing unit 1702.

[0318] The receiving unit 1701 is used to receive PPDU, the PPDU is NDP, the PPDU includes an Extremely High Throughput Signaling Field EHT-SIG, the EHT-SIG has 1 symbol, and the EHT-SIG uses BPSK, 1 / 2 code rate modulation;

[0319] Processing unit 1702 is used to perform channel estimation through the NDP.

[0320] In this way, Bfee can determine the relevant information of NDP users based on the AID in the NDP's EHT-SIG. This allows it to accurately determine whether it is a user that needs to perform channel sensing and report beamforming.

[0321] The transmission device 1600 can be understood as Bfee. The transmission device 1700 can be, for example, a site or access point, or the transmission device 1700 can be deployed at a site or access point. The processing unit 1702 of the transmission device 1700 can be a processor, and the receiving unit 1701 of the transmission device 1700 can be a transceiver.

[0322] In some embodiments, the user of the NDP is a site, and the AID indicated by the AID subfield is the AID of the site.

[0323] In some embodiments, the users of the NDP are multiple sites, and the AID indicated by the user field is 0, indicating that the NDP is sent in a broadcast manner.

[0324] In some embodiments, the user of the NDP is an access point, and the AID indicated by the AID subfield is a set value.

[0325] In some embodiments, the PPDU further includes a U-SIG, which includes a format subfield and / or a compression subfield, the format subfield or the compression subfield indicating that the PPDU is an NDP.

[0326] In some embodiments, the PPDU further includes U-SIG and EHT-LTF, wherein the U-SIG includes a space-time stream number subfield indicating the space-time stream number, and the number of EHT-LTFs is greater than the space-time stream number.

[0327] For details regarding the embodiments of the transmission devices described above, please refer to the relevant content of the method embodiments described above. Further details will not be provided here.

[0328] This application also provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a computer, implements the functions of any of the above method embodiments.

[0329] This application also provides a computer program product that, when executed by a computer, implements the functions of any of the above method embodiments.

[0330] It should also be understood that the first, second, third, fourth and various numerical designations used herein are merely for descriptive convenience and are not intended to limit the scope of this application.

[0331] It should be understood that the term "and / or" in this article is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. Additionally, the character " / " in this article generally indicates that the preceding and following related objects have an "or" relationship.

[0332] It should be understood that in the various embodiments of this application, the order of the above-mentioned processes does not imply the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of this application.

[0333] Those skilled in the art will recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0334] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working processes of the systems, devices, and units described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be detailed here.

[0335] In the several embodiments provided in this application, it should be understood that the disclosed systems, apparatuses, and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for instance, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through some interfaces; the indirect coupling or communication connection between apparatuses or units may be electrical, mechanical, or other forms.

[0336] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0337] In addition, the functional units in the various embodiments of this application can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit.

[0338] If the aforementioned functions are implemented as software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or a portion of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of this application. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0339] The steps in the method of this application embodiment can be adjusted, combined, or deleted according to actual needs.

[0340] The modules in the device of this application embodiment can be merged, divided, and deleted according to actual needs.

[0341] The above-described embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit it. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

Claims

1. A PPDU transmission method, It is characterized in that include: Generate a physical layer protocol data unit PPDU, wherein the PPDU includes a universal-signaling field U-SIG; The U-SIG includes a subfield indicating that the PPDU is a Null Data Packet (NDP); The PPDU is sent.

2. The method according to claim 1, It is characterized in that The PPDU also includes an Extremely High Throughput-Short Training Field (EHT-STF) adjacent to and following the U-SIG.

3. The method according to claim 1 or 2, It is characterized in that The subfield indicating that the PPDU is an NDP is an NDP indication subfield, a PPDU format subfield, or a subfield indicating the number of EHT-SIG symbols in the U-SIG.

4. The method according to any one of claims 1 to 3, It is characterized in that The U-SIG also includes a spatial stream number subfield and / or a subfield indicating the number of very high throughput-long training field EHT-LTF symbols, and the spatial stream number subfield and / or the subfield indicating the number of EHT-LTF symbols indicate the number of spatial streams and the number of EHT-LTF symbols.

5. A method for transmitting a PPDU, It is characterized in that include: Generate a PPDU, where the PPDU is an NDP, the PPDU includes an extremely high throughput-signaling field EHT-SIG, the number of symbols of the EHT-SIG is 1, and the EHT-SIG adopts BPSK, 1 / 2 code rate modulation; The PPDU is sent.

6. The method according to claim 5, It is characterized in that The PPDU further includes a universal-signaling field U-SIG, the U-SIG including a subfield indicating the number of EHT-SIG symbols, and the subfield indicating the number of EHT-SIG symbols indicates that the number of EHT-SIG symbols is any value greater than or equal to 1.

7. The method according to claim 6, It is characterized in that The subfield indicating the number of EHT-SIG symbols indicates that the number of EHT-SIG symbols is 1, and the U-SIG further includes a coding and modulation strategy MCS subfield, and the MCS subfield indicates that the EHT-SIG adopts BPSK, 1 / 2 code rate modulation.

8. The method according to claim 6 or 7, It is characterized in that The NDP indication subfield or the PPDU format subfield in the U-SIG indicates that the PPDU is in non-compressed mode.

9. The method according to any one of claims 5 to 8, It is characterized in that The space-time stream number subfield and / or the subfield indicating the number of EHT-LTF symbols in the EHT-SIG indicates the space-time stream number and the EHT-LTF symbol number.

10. A method for transmitting a PPDU, It is characterized in that include: Generate a PPDU, where the PPDU is an NDP, the PPDU includes an EHT-SIG, the EHT-SIG includes an AID subfield indicating an association identifier AID, where the AID is used to indicate information related to a user of the NDP; The PPDU is sent.

11. The method according to claim 10, It is characterized in that The user of the NDP is a site, and the AID indicated by the AID subfield is the AID of the site; or The users of the NDP are multiple sites, and the AID indicated by the user field is 0, indicating that the NDP is sent in the form of broadcast; or The user of the NDP is an access point, and the AID indicated by the AID subfield is a set value.

12. The method according to claim 10 or 11, It is characterized in that The PPDU further includes a U-SIG, wherein the U-SIG includes a format subfield and / or a compression subfield, and the format subfield or the compression subfield indicates that the PPDU is an NDP.

13. The method according to any one of claims 10 to 12, It is characterized in that The PPDU further includes a U-SIG and an EHT-LTF, the U-SIG includes a space-time stream number subfield indicating the number of space-time streams, and the number of the EHT-LTFs is greater than the number of space-time streams.

14. A method for transmitting a PPDU, It is characterized in that include: receiving a PPDU, the PPDU being an NDP, the PPDU including a universal-signaling field U-SIG; The U-SIG includes a subfield indicating that the PPDU is a Null Data Packet (NDP); Channel estimation is performed through the NDP.

15. The method according to claim 14, It is characterized in that The PPDU also includes an Extremely High Throughput-Short Training Field (EHT-STF) adjacent to and following the U-SIG.

16. The method according to claim 14 or 15, It is characterized in that The subfield indicating that the PPDU is an NDP is an NDP indication subfield, a PPDU format subfield, or a subfield indicating the number of EHT-SIG symbols in the U-SIG.

17. The method according to claims 14-16, It is characterized in that The U-SIG also includes a spatial stream number subfield and / or a subfield indicating the number of very high throughput-long training field EHT-LTF symbols, and the spatial stream number subfield and / or the subfield indicating the number of EHT-LTF symbols indicate the number of space-time streams and the number of EHT-LTF symbols.

18. A method for transmitting a PPDU, It is characterized in that include: Receive a PPDU, where the PPDU is an NDP, the PPDU includes an extremely high throughput-signaling field EHT-SIG, the number of symbols of the EHT-SIG is 1, and the EHT-SIG adopts BPSK, 1 / 2 code rate modulation; Channel estimation is performed through the NDP.

19. The method according to claim 18, It is characterized in that The PPDU further includes a universal-signaling field U-SIG, the U-SIG including a subfield indicating the number of EHT-SIG symbols, and the subfield indicating the number of EHT-SIG symbols indicates that the number of EHT-SIG symbols is any value greater than or equal to 1.

20. The method according to claim 18 or 19, It is characterized in that The NDP indication subfield or the PPDU format subfield in the U-SIG indicates that the PPDU is in non-compressed mode.

21. The method according to claim 18 or 19, It is characterized in that The subfield indicating the number of EHT-SIG symbols indicates that the number of EHT-SIG symbols is 1, and the U-SIG further includes a coding and modulation strategy MCS subfield, and the MCS subfield indicates that the EHT-SIG adopts BPSK, 1 / 2 code rate modulation.

22. The method according to any one of claims 18 to 21, It is characterized in that The space-time stream number subfield and / or the subfield indicating the number of EHT-LTF symbols in the EHT-SIG indicates the space-time stream number and the EHT-LTF symbol number.

23. A method for transmitting a PPDU, It is characterized in that include: receiving a PPDU, the PPDU being an NDP, the PPDU including an EHT-SIG, the EHT-SIG including an AID subfield indicating an association identifier AID, the AID being used to indicate information related to a user of the NDP; Channel estimation is performed through the NDP.

24. The method according to claim 23, It is characterized in that The user of the NDP is a site, and the AID indicated by the AID subfield is the AID of the site; or The users of the NDP are multiple sites, and the AID indicated by the user field is 0, indicating that the NDP is sent in the form of broadcast; or The user of the NDP is an access point, and the AID indicated by the AID subfield is a set value.

25. The method according to claim 23 or 24, It is characterized in that The PPDU further includes a U-SIG, wherein the U-SIG includes a format subfield and / or a compression subfield, and the format subfield or the compression subfield indicates that the PPDU is an NDP.

26. The method according to any one of claims 23 to 25, It is characterized in that The PPDU further includes a U-SIG and an EHT-LTF, the U-SIG includes a space-time stream number subfield indicating the number of space-time streams, and the number of the EHT-LTFs is greater than the number of space-time streams.

27. A PPDU transmission device, It is characterized in that include: A processing unit and a transceiver unit; wherein: The processing unit is configured to generate a physical layer protocol data unit PPDU, wherein the PPDU includes a universal-signaling field U-SIG; The U-SIG includes a subfield indicating that the PPDU is a Null Data Packet (NDP); The transceiver unit is used to send the PPDU.

28. The transmission device according to claim 27, It is characterized in that The subfield indicating that the PPDU is an NDP is an NDP indication subfield, a PPDU format subfield, or a subfield indicating the number of EHT-SIG symbols in the U-SIG.

29. The transmission device according to claim 27 or 28, It is characterized in that The U-SIG also includes a spatial stream number subfield and / or a subfield indicating the number of very high throughput-long training field EHT-LTF symbols, and the spatial stream number subfield and / or the subfield indicating the number of EHT-LTF symbols indicate the number of spatial streams and the number of EHT-LTF symbols.

30. A PPDU transmission device, It is characterized in that include: A processing unit and a transceiver unit; wherein: The processing unit is configured to generate a PPDU, wherein the PPDU is an NDP, the PPDU includes an extremely high throughput-signaling field EHT-SIG, the number of symbols of the EHT-SIG is 1, and the EHT-SIG adopts BPSK, 1 / 2 code rate modulation; The transceiver unit is used to send the PPDU.

31. The transmission device according to claim 30, It is characterized in that The PPDU further includes a universal-signaling field U-SIG, the U-SIG including a subfield indicating the number of EHT-SIG symbols, and the subfield indicating the number of EHT-SIG symbols indicates that the number of EHT-SIG symbols is any value greater than or equal to 1.

32. The transmission device according to claim 31, It is characterized in that The subfield indicating the number of EHT-SIG symbols indicates that the number of EHT-SIG symbols is 1, and the U-SIG further includes a coding and modulation strategy MCS subfield, and the MCS subfield indicates that the EHT-SIG adopts BPSK, 1 / 2 code rate modulation.

33. The transmission device according to claim 31 or 32, It is characterized in that The NDP indication subfield or the PPDU format subfield in the U-SIG indicates that the PPDU is in non-compressed mode.

34. The transmission device according to any one of claims 30 to 33, It is characterized in that The space-time stream number subfield and / or the subfield indicating the number of EHT-LTF symbols in the EHT-SIG indicates the space-time stream number and the EHT-LTF symbol number.

35. A PPDU transmission device, It is characterized in that It includes a processing unit and a transceiver unit; wherein: The transceiver unit is configured to receive a PPDU, wherein the PPDU is an NDP, and the PPDU includes a universal-signaling field U-SIG; the U-SIG includes a subfield indicating that the PPDU is a null data packet NDP; The processing unit is used to perform channel estimation through the NDP.

36. The transmission device according to claim 35, It is characterized in that The subfield indicating that the PPDU is an NDP is an NDP indication subfield, a PPDU format subfield, or a subfield indicating the number of EHT-SIG symbols in the U-SIG.

37. The transmission device according to claim 35 or 36, It is characterized in that The U-SIG also includes a spatial stream number subfield and / or a subfield indicating the number of very high throughput-long training field EHT-LTF symbols, and the spatial stream number subfield and / or the subfield indicating the number of EHT-LTF symbols indicate the number of space-time streams and the number of EHT-LTF symbols.

38. A PPDU transmission device, It is characterized in that It includes a transceiver unit and a processing unit; wherein: The transceiver unit is configured to receive a PPDU, wherein the PPDU is an NDP, the PPDU includes an extremely high throughput-signaling field EHT-SIG, the number of symbols of the EHT-SIG is 1, and the EHT-SIG adopts BPSK, 1 / 2 code rate modulation; The processing unit is used to perform channel estimation through the NDP.

39. The transmission device according to claim 38, It is characterized in that The PPDU further includes a universal-signaling field U-SIG, the U-SIG including a subfield indicating the number of EHT-SIG symbols, and the subfield indicating the number of EHT-SIG symbols indicates that the number of EHT-SIG symbols is any value greater than or equal to 1.

40. The transmission device according to claim 38 or 39, It is characterized in that The subfield indicating the number of EHT-SIG symbols indicates that the number of EHT-SIG symbols is 1, and the U-SIG further includes a coding and modulation strategy MCS subfield, and the MCS subfield indicates that the EHT-SIG adopts BPSK, 1 / 2 code rate modulation.

41. The transmission device according to any one of claims 38 to 40, It is characterized in that The space-time stream number subfield and / or the subfield indicating the number of EHT-LTF symbols in the EHT-SIG indicates the space-time stream number and the EHT-LTF symbol number.

42. A PPDU transmission device, It is characterized in that include: A processor and a transceiver, when the processor executes the computer program or instructions in the memory, implements the method according to any one of claims 1 to 4, or implements the method according to any one of claims 5 to 9, or implements the method according to any one of claims 10 to 13, or implements the method according to any one of claims 14 to 17, or implements the method according to any one of claims 18 to 22, or implements the method according to any one of claims 23 to 26.

43. A PPDU transmission device, It is characterized in that include: A processor, the processor being coupled to a memory, and configured to read instructions in the memory, and to implement, according to the instructions, a method as described in any one of claims 1 to 4, or a method as described in any one of claims 5 to 9, or a method as described in any one of claims 10 to 13, or a method as described in any one of claims 14 to 17, or a method as described in any one of claims 18 to 22, or a method as described in any one of claims 23 to 26.

44. A PPDU transmission device, used to implement the method as described in any one of claims 1-4, or to implement the method as described in any one of claims 5-9, or to implement the method as described in any one of claims 10-13, or to implement the method as described in any one of claims 14-17, or to implement the method as described in any one of claims 18-22, or to implement the method as described in any one of claims 23-26.

45. A computer readable storage medium, It is characterized in that The computer-readable storage medium stores computer instructions, which, when executed by a processor, implement the method according to any one of claims 1 to 4, or implement the method according to any one of claims 5 to 9, or implement the method according to any one of claims 10 to 13, or implement the method according to any one of claims 14 to 17, or implement the method according to any one of claims 18 to 22, or implement the method according to any one of claims 23 to 26.

46. ​​A computer program product, It is characterized in that When the computer program product is executed on a computer, it implements the method according to any one of claims 1 to 4, or implements the method according to any one of claims 5 to 9, or implements the method according to any one of claims 10 to 13, or implements the method according to any one of claims 14 to 17, or implements the method according to any one of claims 18 to 22, or implements the method according to any one of claims 23 to 26.

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