Method and communication device for transmitting physical layer protocol data units - Patents.com

Abstract

This application provides a method and a communication device for transmitting a PPDU. An AP sends a trigger frame to trigger at least one STA to transmit an uplink PPDU. After receiving the trigger frame, the at least one STA transmits each uplink PPDU. The uplink PPDU includes a data field and an LTF. The data field is carried on a distributed RU. The LTF is carried on all subcarriers in a first transmission bandwidth. The first transmission bandwidth is a bandwidth occupied by the distributed RU that is assigned by the AP to the at least one STA to transmit the uplink PPDU. Alternatively, the LTF is carried on all subcarriers of multiple consecutive RUs corresponding to the distributed RU. According to the above solution, it can be ensured that the average power of the data portion transmitted by the AP is increased, and the PAPR of the LTF can also be guaranteed, thereby ensuring system performance.

Description

[Technical field]

[0002] The present application relates to the field of communications, and more particularly to a method and a communication device for transmitting a physical layer protocol data unit (PPDU). [Background technology]

[0003] Orthogonal frequency division multiple access (OFDMA) technology is introduced into wireless local area network (WLAN), and then the concept of resource unit (RU) is introduced. In particular, the entire bandwidth is divided into multiple resource units (RUs). In other words, frequency domain resources are allocated in units of resource units instead of channels. For example, one 20MHz channel may include multiple resource units (RUs), such as 26-tone RU, 52-tone RU, and 106-tone RU. A tone indicates the number of subcarriers. In addition, a RU may be 242-tone RU, 484-tone RU, or 996-tone RU, etc.

[0004] The communication mode in the existing wireless local area network (WLAN) severely limits the maximum transmission power and the maximum frequency spectrum density. The transmission power cannot exceed the maximum power, and the transmission power spectrum density cannot exceed the maximum power spectrum density. Therefore, as the transmission bandwidth increases, how to increase the transmission power of data and guarantee the peak average power ratio (PAPR) of long training fields (LTFs) when the maximum power spectrum density limit is satisfied is an urgent problem to be solved. Summary of the Invention

[0005] This application provides a method for transmitting a PPDU to ensure that the average power of the data portion transmitted by an access point (AP) is increased and to ensure the PAPR of the LTF, thereby ensuring system performance.

[0006] According to a first aspect, a method for transmitting a PPDU is provided. The method includes: a station (STA) receiving a trigger frame from an AP, the trigger frame being utilized to trigger at least one STA including the STA to transmit an uplink physical layer protocol data unit (PPDU); and the STA transmitting the PPDU to the AP based on the trigger frame. The PPDU includes a data field and a long training field (LTF) utilized for channel estimation. The data field is carried on distributed RUs. The distributed RUs include multiple subcarrier groups distributed in a frequency domain. One subcarrier group includes one subcarrier or includes at least two consecutive subcarriers. The LTF is carried on all subcarriers within a first transmission bandwidth. The first transmission bandwidth is a bandwidth corresponding to the distributed RUs allocated by the AP to the at least one STA to transmit the uplink PPDU.

[0007] It should be understood that the first transmission bandwidth may also be understood as the bandwidth allocated by the AP to the uplink PPDU. In a scenario where all RUs included in the full bandwidth are distributed RUs, or where resource allocation is performed on the full bandwidth using distributed RUs, the first transmission bandwidth is the full bandwidth. In a scenario where the full bandwidth includes both distributed RUs and contiguous RUs, or where resource allocation is performed on some bandwidths within the full bandwidth using distributed RUs and resource allocation is performed on other bandwidths using contiguous RUs, the first transmission bandwidth is the bandwidth occupied by the distributed RUs. For example, it is assumed that the full bandwidth is 40 MHz. In a scenario where resource allocation is performed on the 40 MHz bandwidth using distributed RUs, the first transmission bandwidth is 40 MHz. In a scenario where resource allocation is performed on a 20 MHz bandwidth within the 40 MHz bandwidth using distributed RUs and resource allocation is performed on the other 20 MHz bandwidth using contiguous RUs, the first transmission bandwidth is 20 MHz.

[0008] It should be further understood that the distributed RU carrying the data field may be one RU or multiple RUs. In addition, regardless of which distributed RU or distributed RUs in the first transmission bandwidth are the distributed RU carrying the data field, the bandwidth occupied by the distributed RU is the first transmission bandwidth. For example, when the distributed RUs carrying the data field are distributed RU#1 and distributed RU#2, the bandwidth occupied by distributed RU#1 and distributed RU#2 is the first transmission bandwidth. When the distributed RUs carrying the data field are distributed RU#3 and distributed RU#4, the bandwidth occupied by distributed RU#3 and distributed RU#4 is also the first transmission bandwidth.

[0009] In the prior art, when a PPDU is transmitted in a first transmission bandwidth, the data field and the LTF in the PPDU are carried on all subcarriers in the first transmission bandwidth. Since the LTF carried on all subcarriers in the first transmission bandwidth is designed, the PAPR of the LTF can be guaranteed. However, according to the method for transmitting a PPDU provided in this application, in a scenario in which the data field is carried on distributed RUs, the LTF is carried on all subcarriers in the first transmission bandwidth instead of the distributed RUs. Therefore, it can be guaranteed that the average power of the data portion transmitted by the AP is increased, and the PAPR of the LTF can be guaranteed, thereby ensuring system performance.

[0010] According to a second aspect, a method for transmitting a PPDU is provided. The method includes: a STA receives a trigger frame from an AP, the trigger frame being utilized to trigger at least one STA, including the STA, to transmit an uplink physical layer protocol data unit PPDU; and the STA transmits the physical layer protocol data unit PPDU to the AP based on the trigger frame. The PPDU includes a data field and a long training field LTF utilized for channel estimation. The data field is carried on distributed RUs. The distributed RUs include a plurality of subcarrier groups distributed in a frequency domain. A subcarrier group includes one subcarrier or includes at least two consecutive subcarriers. The LTF is carried on all subcarriers of the plurality of consecutive RUs. The plurality of consecutive RUs are consecutive RUs corresponding to the distributed RUs. Each consecutive RU includes a plurality of subcarriers that are consecutive in a frequency domain.

[0011] In this application, a consecutive RU is an RU that includes multiple consecutive subcarriers, or a consecutive RU is an RU that includes two consecutive subcarrier groups, where the multiple subcarriers included in each consecutive subcarrier group are consecutive, and the two consecutive subcarrier groups are spaced apart only by one or more of guard subcarriers, null subcarriers, or DC subcarriers.

[0012] It should be understood that consecutive RUs and distributed RUs are corresponding concepts. For a bandwidth, multiple subcarriers included in the bandwidth may form multiple consecutive RUs or multiple distributed RUs. In other words, for a subcarrier, in the consecutive RU allocation mechanism, the subcarrier belongs to a consecutive RU, and in the distributed RU allocation mechanism, the subcarrier belongs to a distributed RU. The consecutive RUs and distributed RUs may include some of the same subcarriers. In this application, the multiple consecutive RUs corresponding to the carried data field are multiple consecutive RUs that include all subcarriers of the distributed RU and include a minimum number of subcarriers. Any one consecutive RU among the multiple consecutive RUs corresponding to one distributed RU includes some subcarriers of the distributed RU. In the prior art, when a PPDU is transmitted on all subcarriers of multiple consecutive RUs, the data field and the LTF in the PPDU are carried on all subcarriers of the multiple consecutive RUs. Since the LTF carried on all subcarriers of the multiple consecutive RUs is designed, the PAPR of the LTF can be guaranteed. However, according to the method for transmitting PPDU provided in this application, in a scenario where data is carried on distributed RUs, the LTF is carried on all subcarriers in the multiple consecutive RUs corresponding to the distributed RUs instead of the distributed RUs. Thus, it can ensure that the average power of the data portion transmitted by the AP is increased, and the PAPR of the LTF can be guaranteed, thereby ensuring system performance. In addition, compared with the scheme in which the LTF is carried on all subcarriers in the first transmission bandwidth, the scheme in which the LTF is carried only on all subcarriers of the multiple consecutive RUs corresponding to the distributed RUs can reduce redundant subcarriers for transmission.

[0013] Regarding the first and second aspects, in some implementations, the method further includes the STA obtaining the LTFs carried on all the subcarriers based on the values ​​of the LTF sequence and the matrix P.

[0014] In one design, the dimensionality of matrix P is determined based on the number of STAs triggered by the trigger frame, the maximum number of STAs supported by the system, and the maximum number of spatial streams supported by a single STA in the at least one STA.

[0015] In other designs, the dimension of the matrix P is N LTF ×N LTF In other words, the matrix P is LTF Row x N LTF is a column matrix. LTF is the number of OFDM symbols contained in the LTF, i.e., the number of OFDM symbols for transmitting the LTF. LTF is determined based on the total number of streams carried by each STA in the first transmission bandwidth.

[0016] With respect to the first and second aspects, in some implementations, the STA obtaining the LTF to be carried on all subcarriers based on the value of the LTF sequence and the matrix P includes the STA determining a corresponding row from the matrix P based on an order of the STA within the at least one STA, and the STA obtaining the LTF to be carried on all subcarriers based on the corresponding row determined from the matrix P and the value of the LTF sequence.

[0017] In one implementation, the dimension of the matrix P is N LTF ×N LTF N LTF is the number of OFDM symbols contained in the LTF, (N u ×N ms )≦N LTF ≦(N mu ×N ms ), and N u is the number of STAs triggered by the trigger frame, and N mu is the maximum number of STAs supported by the system, and N msis the maximum number of spatial streams supported by a single STA in the at least one STA. The i-th STA in the at least one STA is the (i-1)×N ms +1 to i×N ms corresponds to the th row.

[0018] In another implementation, any STA in the at least one STA may determine a row corresponding to the STA from the matrix P based on an indication of an SS Allocation field in a User Info Field in a trigger frame received by the STA. In particular, the SS Allocation field includes two subfields. One is a starting spatial stream subfield indicating an assigned starting spatial stream index, and the other is a spatial stream number subfield indicating the number of assigned spatial streams. The STA selects rows from (starting spatial stream index+1)th to (starting spatial stream index+number of assigned streams)th in the matrix P. In particular, the matrix P of STA i may be i is the I in matrix P i +1st to I i +NUM i The th row is P i and I i is the starting spatial stream sequence number of the i-th user, and starting spatial stream sequence number I i is obtained by sorting all the streams of all the users on the first transmission bandwidth, and NUM i is the number of streams of the i-th user, and I i and NUM i is indicated by the SS assignment field in the user information field of the STA.

[0019] Regarding the first and second aspects, in some implementations, the LTF X carried on the k-th subcarrier among all the subcarriers may be k , and the LTF X carried on the d-th subcarrier among all the subcarriers.d X k =P i ×LTF k , and X d =F×LTF d Each of the following conditions is satisfied.

[0020] The kth subcarrier is a data subcarrier, the dth subcarrier is a pilot subcarrier, and P i is the (i-1)×N ms +1 to i×N ms The first S in the th row i row, (i-1)×N in matrix P ms +1 to i×N ms The th row is the row in matrix P corresponding to the sequence number i of the STA, and matrix P has N LTF ×N LTF is the orthogonal mapping matrix of N LTF is the number of orthogonal frequency division multiplexing OFDM symbols contained in the LTF, (N u ×N ms )≦N LTF ≦(N mu ×N ms ), and N u is the number of STAs triggered by the trigger frame, and N mu is the maximum number of STAs supported by the system, and N ms is the maximum number of spatial streams supported by a single STA, i is the sequence number of the STA, and 1≦i≦N u And S i is the number of spatial streams actually transmitted by the STA with sequence number i, and 1≦S i ≦N ms And LTF k is the value of the LTF sequence corresponding to the kth subcarrier, and LTF d is the value of the LTF sequence corresponding to the d-th subcarrier, and F is the first row of the matrix P.

[0021] In the prior art, the matrix multiplied by the LTF sequence is matrix P, where matrix P is determined by the STA based on the number of spatial streams actually transmitted by the STA. For example, assuming that the number of spatial streams actually transmitted by the STA is 2, the matrix P corresponding to the STA is a 2×2 orthogonal mapping matrix specified by the protocol.

[0022] However, in this embodiment of the present application, the matrix P i is a matrix P shared among at least one STA based on the number of spatial streams actually transmitted by the STA (i.e., the above N LTF ×N LTF The LTF is determined by the STA from the orthogonal mapping matrix of the LTF. In this way, it is possible to prevent inter-user interference caused by the transmission of the LTF by each STA.

[0023] Regarding the first and second aspects, in some implementations, i is: i=(T F -T L ) / T c Meet +1.

[0024] T F is the duration between the reception of a trigger frame by a STA and the reception of a user information field corresponding to the STA, and T L is the duration from the reception of a trigger frame by the STA to the reception of the first user information field in the trigger frame, and T C is the length of the user information field corresponding to the STA.

[0025] In the common field of the trigger frame, B55=0 indicates that the first user information field in the User Info List is an extension of the common field and is called the Special User Info Field. In this case, i=i'-1 must be set. In other words, when B55=0, the special user information field is used as an extension of the common field, and one less user information field is actually assigned to the user. Therefore, the actual user sequence number (STA sequence number i) is the sequence number i' of the user information field minus one, i.e., i=i'-1. When B55=1, the user sequence number (STA sequence number) is equal to the sequence number of the user information field.

[0026] It should be noted that i may alternatively be determined in other manners, for example, the sequence number of each STA may be carried in the trigger frame, for example, the sequence number of the corresponding STA is carried in each user information field in the trigger frame.

[0027] According to a third aspect, a method for transmitting a PPDU is provided. The method includes: an access point AP transmits a trigger frame to at least one station STA, the trigger frame being used to trigger the at least one STA to transmit an uplink physical layer protocol data unit PPDU; and the AP receives each PPDU from the at least one STA. One of the PPDUs includes a data field and a long training field LTF used for channel estimation. The data field is carried on a distributed resource unit RU. The distributed RU includes a plurality of subcarrier groups distributed in a frequency domain. One subcarrier group includes one subcarrier or includes at least two consecutive subcarriers. The LTF is carried on all subcarriers in a first transmission bandwidth. The first transmission bandwidth is a bandwidth corresponding to the distributed RU assigned by the AP to the at least one STA to transmit the uplink PPDU.

[0028] According to the method for transmitting PPDU provided in this application, in a scenario where data is carried on distributed RUs, the LTF is carried on all subcarriers in the first transmission bandwidth instead of the distributed RUs, so that the average power of the data portion transmitted by the AP can be guaranteed to increase, and the PAPR of the LTF can be guaranteed, thereby ensuring the system performance.

[0029] Regarding the third aspect, in some implementations, the method further includes the AP determining channel coefficients of data subcarriers within the first transmission bandwidth based on the LTF received on the data subcarriers within the first transmission bandwidth.

[0030] Based on this solution, the LTF of at least one STA is carried on all subcarriers in the first transmission bandwidth, and the AP may determine a channel coefficient of any data subcarrier in the first transmission bandwidth based on the LTF received on the data subcarrier, where the channel coefficient includes a channel coefficient of each STA in the at least one STA for the data subcarrier.

[0031] Regarding the third aspect, in some implementations, a channel coefficient H of a k-th subcarrier in all subcarriers within the first transmission bandwidth is calculated. k teeth,

[0032]

number

[0033] Meet the following.

[0034] The kth subcarrier is a data subcarrier, Y k is the LTF received by the AP on the kth subcarrier, and N LTF is the number of OFDM symbols contained in the LTF, (N u ×N ms )≦N LTF ≦(N mu ×N ms ), and N u is the number of STAs triggered by the trigger frame, and N mu is the maximum number of STAs supported by the system, and N ms is the maximum number of spatial streams supported by a single STA, and P r * , P r is the conjugate transpose of

[0035]

number

[0036] And P iis the (i-1)×N ms +1 to i×N ms The first S in the th row i row, (i-1)×N in matrix P ms +1 to i×N ms The th row is the row in matrix P that corresponds to the sequence number i of the STA, and 1≦S i ≦N ms where i∈[1,N u ], i is the sequence number of the STA, and S i is the number of spatial streams actually transmitted by the STA with sequence number i, and the matrix P is N LTF ×N LTF is the orthogonal mapping matrix of LTF k is the value of the LTF sequence corresponding to the kth subcarrier.

[0037] Regarding the third aspect, in some implementations, the method includes: k and the AP demodulating the data transmitted by the STA with sequence number i based on the channel coefficient of the STA with sequence number i for each data subcarrier in all subcarriers in the first transmission bandwidth. The channel coefficient of the STA with sequence number i for the kth subcarrier is expressed as H k Q in 1_i th to Q 2_i th column, P i , P r Q in 1_i th to Q 2_i This is the th line.

[0038] Based on this solution, the AP may obtain a channel coefficient of at least one STA for each data subcarrier in the first transmission bandwidth, and then extract a channel coefficient of each STA for each data subcarrier in the first transmission bandwidth from the channel coefficient. Thus, for any STA, the AP may demodulate the data transmitted by the STA based on the channel coefficient of the STA for each data subcarrier in the first transmission bandwidth, and obtain the data transmitted by the STA.

[0039] According to a fourth aspect, a method for transmitting a PPDU is provided, the method includes: an access point AP transmits a trigger frame to at least one station STA, the trigger frame is used to trigger the at least one STA to transmit an uplink physical layer protocol data unit PPDU, and the AP receives each PPDU from the at least one STA, one of the PPDUs includes a data field and a long training field LTF used for channel estimation, the data field is carried on a distributed resource unit RU, the distributed RU includes a plurality of subcarrier groups distributed in a frequency domain, one subcarrier group includes one subcarrier or includes at least two consecutive subcarriers, the LTF is carried on all subcarriers of the plurality of consecutive RUs, the plurality of consecutive RUs are consecutive RUs corresponding to the distributed RUs, and each consecutive RU includes a plurality of subcarriers that are consecutive in the frequency domain.

[0040] According to the method for transmitting PPDU provided in this application, in a scenario where data is carried on distributed RUs, the LTF is carried on all subcarriers in multiple consecutive RUs corresponding to the distributed RUs instead of the distributed RUs. Thus, it can ensure that the average power of the data portion transmitted by the AP is increased, and the PAPR of the LTF can be guaranteed, thereby ensuring system performance. In addition, compared with the scheme in which the LTF is carried on all subcarriers in the first transmission bandwidth, the scheme in which the LTF is carried only on all subcarriers of multiple consecutive RUs corresponding to the distributed RUs can reduce redundant subcarriers for transmission.

[0041] Regarding the fourth aspect, in some implementations, the method further includes the AP determining a channel coefficient for each data subcarrier in all subcarriers of the t-th consecutive RU based on the LTF received on all data subcarriers in the t-th consecutive RU within the second transmission bandwidth.

[0042] The second transmission bandwidth is a bandwidth corresponding to a plurality of consecutive RUs assigned by the AP to the at least one STA for transmitting a respective LTF. In particular, each STA in the at least one STA transmits an LTF on all subcarriers in the plurality of consecutive RUs. In other words, each STA corresponds to a plurality of consecutive RUs, and the sum of the bandwidths of the consecutive RUs in the set of consecutive RUs corresponding to the at least one STA is the second transmission bandwidth. The set of consecutive RUs corresponding to the at least one STA includes the consecutive RUs corresponding to each STA in the at least one STA, and any two consecutive RUs in the set are different.

[0043] Regarding the fourth aspect, in some implementations, the channel coefficient H of the k'th subcarrier in all subcarriers of the tth consecutive RU is k’ (t) teeth,

[0044]

number

[0045] Meet the following.

[0046] The k'th subcarrier is a data subcarrier, and Y k’ is the LTF received by the AP on the k'th subcarrier, and N LTF is the number of OFDM symbols contained in the LTF, (N u ×N ms )≦N LTF ≦(N mu ×N ms ), and N u is the number of STAs triggered by the trigger frame, and N mu is the maximum number of STAs supported by the system, and N ms is the maximum number of spatial streams supported by a single STA, (P r (t) ) * , P r (t) is the conjugate transpose of

[0047]

number

[0048] where u is the number of STAs whose corresponding LTFs are carried on the t-th consecutive RU;

[0049]

number

[0050] is the (i t -1) × N ms +1st to i t ×N ms The first in the th row

[0051]

number

[0052] row, and (i t -1) × N ms +1st to i t ×N ms The th row is the sequence number of the STA i in the matrix P. t is the row corresponding to i t ∈[1,N u ], and i t is the sequence number of the STA that transmits the LTF using the tth consecutive RU,

[0053]

number

[0054] is sequence number i t is the number of spatial streams actually transmitted by the STA with

[0055]

number

[0056] and the matrix P is N LTF ×N LTF is the orthogonal mapping matrix of LTF k’ (t) is the value of the LTF sequence corresponding to the k'th subcarrier of the tth RU.

[0057] It should be understood that the number of STAs for which the corresponding LTFs are carried on different consecutive RUs may vary, in other words, the value of u may vary when t has different values.

[0058] i t It should be further understood that i is a sequence number of a STA in at least one STA, and the STA transmits an LTF using the t-th consecutive RU. t is not the sequence number of a STA among the u STAs that transmits an LTF using the tth consecutive RU.

[0059] Based on this solution, for any STA, the AP may obtain channel coefficients of each data subcarrier in each of multiple contiguous RUs that correspond to the distributed RUs carrying the STA's data.

[0060] Regarding the fourth aspect, in some implementations, the method includes: k’ Based on sequence number i t For each data subcarrier of each consecutive RU in the plurality of consecutive RUs corresponding to the STA having sequence number i t and the AP determines the channel coefficient of the STA having sequence number i t For each data subcarrier of each consecutive RU in the plurality of consecutive RUs corresponding to the STA having sequence number i t Based on the channel coefficient of the STA with sequence number i t and demodulating data transmitted by the STA having sequence number i. t The LTF of a STA with sequence number i is carried on the t-th consecutive RU, and the LTF of a STA with sequence number i is carried on the k'-th subcarrier in the t-th consecutive RU. t The channel coefficient of the STA with k’ (t) Within

[0061]

number

[0062] From

[0063]

number

[0064] is the th column,

[0065]

number

[0066] , P r (t) Within

[0067]

number

[0068] From

[0069]

number

[0070] This is the th line.

[0071] Based on this solution, the AP knows which consecutive RUs carry the LTFs transmitted by each STA. Therefore, for any STA, the AP can know the channel coefficients of the STA for the data subcarriers in each of the multiple consecutive RUs corresponding to the STA according to the above formula. In this way, it is equivalent to the AP knowing the channel coefficients of the STA, and the AP can demodulate the data transmitted by the STA based on the channel coefficients of the STA.

[0072] According to a fifth aspect, a communication device is provided. The communication device includes a transceiver unit configured to receive a trigger frame from an access point AP, the trigger frame being used to trigger at least one STA to transmit an uplink physical layer protocol data unit PPDU, and to transmit the PPDU to the AP based on the trigger frame. The PPDU includes a data field and a long training field LTF used for channel estimation. The data field is carried on a distributed resource unit RU. The distributed RU includes multiple subcarrier groups distributed in the frequency domain. One subcarrier group includes one subcarrier or includes at least two consecutive subcarriers. The LTF is carried on all subcarriers in a first transmission bandwidth. The first transmission bandwidth is a bandwidth corresponding to the distributed RU assigned by the AP to the at least one STA to transmit the uplink PPDU.

[0073] According to a sixth aspect, a communication device is provided. The communication device includes a transceiver unit configured to receive a trigger frame from an access point AP, the trigger frame being used to trigger at least one station STA to transmit an uplink physical layer protocol data unit PPDU, and to transmit the physical layer protocol data unit PPDU to the AP based on the trigger frame. The PPDU includes a data field and a long training field LTF used for channel estimation. The data field is carried on a distributed resource unit RU. The distributed RU includes a plurality of subcarrier groups distributed in a frequency domain. A subcarrier group includes one subcarrier or includes at least two consecutive subcarriers. The LTF is carried on all subcarriers of the plurality of consecutive RUs. The plurality of consecutive RUs are consecutive RUs corresponding to the distributed RUs. Each consecutive RU includes a plurality of subcarriers that are consecutive in the frequency domain.

[0074] With regard to the fifth and sixth aspects, in some implementations, the communication device further includes a processing unit configured to obtain LTFs carried on all subcarriers based on values ​​of the LTF sequence and a matrix P, the number of dimensions of the matrix P being determined based on the number of STAs triggered by the trigger frame, the maximum number of STAs supported by the system, and the maximum number of spatial streams supported by a single STA in the at least one STA.

[0075] With regard to the fifth and sixth aspects, in some implementations, the processing unit is configured to determine a corresponding row from the matrix P based on an order of communication devices in at least one STA, and obtain the LTFs to be carried on all subcarriers based on the corresponding row determined from the matrix P and the value of the LTF sequence.

[0076] Regarding the fifth and sixth aspects, in some implementations, the LTF X carried on the k-th subcarrier among all the subcarriers may be k , and the LTF X carried on the d-th subcarrier among all the subcarriers. d X k =P i ×LTF k , and X d =F×LTF d Each of the following conditions is satisfied.

[0077] The kth subcarrier is a data subcarrier, the dth subcarrier is a pilot subcarrier, and P i is the (i-1)×N ms +1 to i×N ms The first S in the th row i row, (i-1)×N in matrix P ms +1 to i×N ms The th row is the row in matrix P corresponding to the sequence number i of the STA, and matrix P has N LTF ×N LTF is the orthogonal mapping matrix of N LTFis the number of orthogonal frequency division multiplexing OFDM symbols contained in the LTF, (N u ×N ms )≦N LTF ≦(N mu ×N ms ), and N u is the number of STAs triggered by the trigger frame, and N mu is the maximum number of STAs supported by the system, and N ms is the maximum number of spatial streams supported by a single STA, i is the sequence number of the STA, and 1≦i≦N u And S i is the number of spatial streams actually transmitted by the STA with sequence number i, and 1≦S i ≦N ms And LTF k is the value of the LTF sequence corresponding to the kth subcarrier, and LTF d is the value of the LTF sequence corresponding to the d-th subcarrier, and F is the first row of the matrix P.

[0078] Regarding the fifth and sixth aspects, in some implementations, i is: i=(T F -T L ) / T c Meet +1.

[0079] T F is the duration between the reception of a trigger frame by a STA and the reception of a user information field corresponding to the STA, and T L is the duration from the reception of a trigger frame by the STA to the reception of the first user information field in the trigger frame, and T C is the length of the user information field corresponding to the STA.

[0080] According to a seventh aspect, a communication device is provided. The communication device includes a transceiver unit configured to transmit a trigger frame to at least one station STA, the trigger frame being used to trigger the at least one STA to transmit an uplink physical layer protocol data unit PPDU, and to receive each PPDU from the at least one STA. One of the PPDUs includes a data field and a long training field LTF used for channel estimation. The data field is carried on a distributed resource unit RU. The distributed RU includes a plurality of subcarrier groups distributed in a frequency domain. One subcarrier group includes one subcarrier or includes at least two consecutive subcarriers. The LTF is carried on all subcarriers in a first transmission bandwidth. The first transmission bandwidth is a bandwidth corresponding to the distributed RU assigned by the access point AP to the at least one STA to transmit the uplink PPDU.

[0081] Regarding the seventh aspect, in some implementations, the communication device further includes a processing unit configured to determine channel coefficients of data subcarriers within the first transmission bandwidth based on the LTF received on the data subcarriers within the first transmission bandwidth.

[0082] Regarding the seventh aspect, in some implementations, a channel coefficient H of a k-th subcarrier in all subcarriers within the first transmission bandwidth may be calculated. k teeth,

[0083]

number

[0084] Meet the following.

[0085] The kth subcarrier is a data subcarrier, Y k is the LTF received by the AP on the kth subcarrier, and NLTF is the number of OFDM symbols contained in the LTF, (N u ×N ms )≦N LTF ≦(N mu ×N ms ) and N u is the number of STAs triggered by the trigger frame, and N mu is the maximum number of STAs supported by the system, and N ms is the maximum number of spatial streams supported by a single STA, and P r * , P r is the conjugate transpose of

[0086]

number

[0087] or

[0088]

number

[0089] It is.

[0090] In one implementation, P i is the (i-1)×N ms +1 to i×N ms The first S in the th row i row, (i-1)×N in matrix P ms +1 to i×N ms The th row is the row in matrix P that corresponds to the sequence number i of the STA, and 1≦S i ≦N ms where i∈[1,N u ], i is the sequence number of the STA, and S i is the number of spatial streams actually transmitted by the STA with sequence number i, and the matrix P is N LTF ×N LTF is the orthogonal mapping matrix of LTFk is the value of the LTF sequence corresponding to the kth subcarrier.

[0091] In other implementations, P i is the I in matrix P i +1st to I i +NUM i th row, I i is the starting spatial stream sequence number of the i-th user, which is obtained by sorting all streams of all users on the first transmission bandwidth, and NUM i is the number of streams of the i-th user, and I i and NUM i is indicated by the SS assignment field in the user information field of STA i. LTF ×N LTF is the orthogonal mapping matrix of N LTF is the number of OFDM symbols contained in the LTF, and k is the value corresponding to the kth subcarrier in the LTF sequence.

[0092] Regarding the seventh aspect, in some implementations, the processing unit may further include: k and further configured to determine, by the AP, a channel coefficient of the STA with sequence number i for each data subcarrier in all subcarriers in the first transmission bandwidth based on H, and demodulate, by the AP, the data transmitted by the STA with sequence number i based on the channel coefficient of the STA with sequence number i for each data subcarrier in all subcarriers in the first transmission bandwidth. In one implementation, the channel coefficient of the STA with sequence number i for the kth subcarrier is k Q in 1_i th to Q 2_i th column, P i , P r Q in 1_i th to Q 2_iIn other implementations, the channel coefficient of the STA with sequence number i for the kth subcarrier is H k I in i +1st to I i +NUM i This is the th column.

[0093] According to an eighth aspect, a communication device is provided. The communication device includes a transceiver unit configured to transmit a trigger frame to at least one station STA, the trigger frame being used to trigger the at least one STA to transmit an uplink physical layer protocol data unit PPDU, and to receive each PPDU from the at least one STA. One of the PPDUs includes a data field and a long training field LTF used for channel estimation. The data field is carried on a distributed resource unit RU. The distributed RU includes a plurality of subcarrier groups distributed in a frequency domain. A subcarrier group includes one subcarrier or includes at least two consecutive subcarriers. The LTF is carried on all subcarriers of the plurality of consecutive RUs. The plurality of consecutive RUs are consecutive RUs corresponding to the distributed RUs. Each consecutive RU includes a plurality of subcarriers that are consecutive in the frequency domain.

[0094] Regarding the eighth aspect, in some implementations, the communication device further includes a processing unit configured to determine a channel coefficient of each data subcarrier in all subcarriers of the t-th consecutive RU based on an LTF received on all data subcarriers of the t-th consecutive RU in a second transmission bandwidth, where the second transmission bandwidth is a bandwidth corresponding to a plurality of consecutive RUs assigned by the access point AP to at least one STA for transmitting each LTF.

[0095] Regarding the eighth aspect, in some implementations, the channel coefficient H of the k′-th subcarrier in all subcarriers of the t-th consecutive RU is k’(t) teeth,

[0096]

number

[0097] Meet the following.

[0098] The k'th subcarrier is a data subcarrier, and Y k’ is the LTF received by the AP on the k'th subcarrier, and N LTF is the number of OFDM symbols contained in the LTF, (N u ×N ms )≦N LTF ≦(N mu ×N ms ) and N u is the number of STAs triggered by the trigger frame, and N mu is the maximum number of STAs supported by the system, and N ms is the maximum number of spatial streams supported by a single STA, (P r (t) ) * , P r (t) is the conjugate transpose of

[0099]

number

[0100] and u is the number of STAs whose corresponding LTFs are carried on the t-th consecutive RU.

[0101] In one implementation,

[0102]

number

[0103] is the (i t -1) × N ms+1st to i t ×N ms The first in the th row

[0104]

number

[0105] row, and (i t -1) × N ms +1st to i t ×N ms The th row is the sequence number of the STA i in the matrix P. t is the row corresponding to i t ∈[1,N u ], and i t is the sequence number of the STA that transmits the LTF using the tth consecutive RU,

[0106]

number

[0107] is sequence number i t is the number of spatial streams actually transmitted by the STA with

[0108]

number

[0109] and the matrix P is N LTF ×N LTF is the orthogonal mapping matrix of LTF k’ (t) is the value of the LTF sequence corresponding to the k'th subcarrier of the tth RU.

[0110]

number

[0111] is the

[0112]

number

[0113] From

[0114]

number

[0115] is the th row,

[0116]

number

[0117] i t is the starting spatial stream sequence number of the th user,

[0118]

number

[0119] i t is the number of streams for the th user,

[0120]

number

[0121] and

[0122]

number

[0123] STA i t The SS assignment field in the user information field of t ∈[1,N u ], and i tis the sequence number of the STA that transmits the LTF using the tth consecutive RU, and N u is the number of at least one STA that is triggered by the trigger frame, and the matrix P is N LTF ×N LTF is the orthogonal mapping matrix of LTF k’ (t) is the value of the LTF sequence corresponding to the k'th subcarrier of the tth RU.

[0124] Regarding the eighth aspect, in some implementations, the processing unit may further include: k’ Based on sequence number i t For each data subcarrier of each consecutive RU in the plurality of consecutive RUs corresponding to the STA having sequence number i t Determine the channel coefficients of the STA with sequence number i t For each data subcarrier of each consecutive RU in the plurality of consecutive RUs corresponding to the STA having sequence number i t Based on the channel coefficient of the STA with sequence number i t and further configured to demodulate data transmitted by the STA having sequence number i t The LTF of a STA with sequence number i is carried on the t-th consecutive RU, and the LTF of a STA with sequence number i is carried on the k'-th subcarrier in the t-th consecutive RU. t The channel coefficient of the STA with k’ (t) Within

[0125]

number

[0126] From

[0127]

number

[0128] is the th column,

[0129]

number

[0130] , P r (t) Within

[0131]

number

[0132] From

[0133]

number

[0134] This is the th line.

[0135] According to a ninth aspect, there is provided an apparatus including a processor. The processor is coupled to a memory and configured to execute instructions in the memory, such that the apparatus may perform a method according to any one of the first to fourth aspects or possible implementations of the first to fourth aspects. Optionally, the apparatus further includes the memory. Optionally, the apparatus further includes an interface circuit, the processor being coupled to the interface circuit.

[0136] According to a tenth aspect, there is provided a processor including an input circuit, an output circuit, and a processing circuit configured to receive a signal using the input circuit and to transmit a signal using the output circuit, such that the processor performs a method according to any one of the first to fourth aspects or possible implementations of the first to fourth aspects.

[0137] In a specific implementation process, the processor may be a chip, the input circuit may be an input pin, the output circuit may be an output pin, and the processing circuit may be a transistor, a gate circuit, a trigger, or various logic circuits, etc. The input signal received by the input circuit may be, for example, but not limited to, received and input by a receiver, and the signal output by the output circuit may be, for example, but not limited to, output to a transmitter and transmitted by the transmitter, and the input circuit and the output circuit may be the same circuit, where the circuit is used as an input circuit and an output circuit at different times. The specific implementation of the processor and the circuit is not limited in the embodiments of this application.

[0138] According to an eleventh aspect, there is provided a processing device including a processor and a memory, the processor being configured to read instructions stored in the memory and to receive signals using the receiver and transmit signals using the transmitter to perform a method according to any one of the first to fourth aspects or possible implementations of the first to fourth aspects.

[0139] Optionally, there are one or more processors and one or more memories.

[0140] Optionally, the memory may be integrated into the processor, or the memory and the processor are located separately.

[0141] In a specific implementation process, the memory may be a non-transitory memory such as a read-only memory (ROM). The memory and the processor may be integrated into the same chip or may be located separately on different chips. The type of memory and the manner in which the memory and the processor are located are not limited in this embodiment of this application.

[0142] The processing device according to the eleventh aspect may be a chip. The processor may be implemented using hardware or software. When the processor is implemented using hardware, the processor may be a logic circuit, an integrated circuit, etc., or when the processor is implemented using software, the processor may be a general-purpose processor and is implemented by reading software code stored in a memory. The memory may be integrated into the processor or may exist independently outside the processor.

[0143] According to a twelfth aspect, there is provided a computer program product. The computer program product includes a computer program (also referred to as code or instructions). When the computer program is executed, it enables a computer to perform a method according to any one of the first to fourth aspects or possible implementations of the first to fourth aspects.

[0144] According to a thirteenth aspect, a computer readable medium is provided. The computer readable medium stores a computer program (also referred to as code or instructions). When the computer program is executed on a computer, the computer is enabled to execute a method according to any one of the first to fourth aspects or possible implementations of the first to fourth aspects.

[0145] According to a fourteenth aspect, the present application provides a chip system. The chip system includes a processor and an interface configured to support a communication device in implementing the functions of any one of the first to fourth aspects or possible implementations of the first to fourth aspects. In a possible design, the chip system further includes a memory, the memory configured to store information and data required by the communication device. The chip system may include a chip, or may include a chip and other separate devices.

[0146] According to a fifteenth aspect, the application provides a functional entity, configured to implement a method according to any one of the first to fourth aspects or possible implementations of the first to fourth aspects.

[0147] According to a sixteenth aspect, there is provided a communication system including the AP described above. Optionally, the communication system may further include the STA described above. [Brief description of the drawings]

[0148] [Figure 1] 1 is a schematic diagram of a communication system according to an embodiment of the present application. [Diagram 2] FIG. 2 is a schematic diagram of the structure of a communication device according to an embodiment of this application; [Diagram 3] FIG. 1 is a schematic diagram of a structure of a chip according to an embodiment of this application. [Figure 4] FIG. 1 is a schematic diagram of possible resource unit allocation schemes in the 20 MHz case. [Diagram 5] FIG. 1 is a schematic diagram of possible resource unit allocation schemes in the 40 MHz case. [Figure 6] FIG. 1 is a schematic diagram of possible resource unit allocation schemes in the 80 MHz case. [Figure 7] FIG. 1 is a schematic diagram of a distributed RU. [Figure 8] FIG. 13 is a schematic diagram of another distributed RU. [Figure 9] FIG. 13 is a schematic diagram of yet another distributed RU. [Figure 10] 2 is a schematic flowchart of a method for transmitting a PPDU according to an embodiment of the present application; [Figure 11] FIG. 2 is a schematic diagram of a frame structure of a trigger frame according to an embodiment of the present application; [Figure 11(a)] FIG. 13 is a schematic diagram of another frame structure of a trigger frame according to an embodiment of the present application; [Figure 11(b)] FIG. 2 is a schematic diagram of a frame structure of a common information portion of a trigger frame according to an embodiment of the present application; [Figure 11(c)] FIG. 2 is a schematic diagram of a frame structure of a user information portion of a trigger frame according to an embodiment of the present application; [Figure 12] FIG. 2 is a schematic diagram of an EHT PPDU format according to an embodiment of this application. [Figure 13] 4 is a schematic flow chart of another method for transmitting PPDU according to an embodiment of the present application; [Figure 14] FIG. 2 is a schematic diagram of the structure of a communication device according to an embodiment of this application; DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0149] The technical solutions of this application are described below with reference to the accompanying drawings.

[0150] The technical solutions in the embodiments of this application are applicable to various communication systems, such as a wireless local area network (WLAN) communication system, a long term evolution (LTE) system, a LTE frequency division duplex (FDD) system, a LTE time division duplex (TDD) system, a universal mobile telecommunication system (UMTS), a worldwide interoperability for microwave access (WiMAX) communication system, a fifth generation (5G) system, a LTE ... th generation (5G) systems, new radio (NR) systems, and sixth generation (6 th This can be applied to the 6G (radio-frequency) system.

[0151] For example, the following uses a WLAN system as an example to describe application scenarios in the embodiments of this application and methods in the embodiments of this application.

[0152] In particular, embodiments of this application may be applied to a WLAN system, and embodiments of this application may be applicable to any protocol in the Institute of Electrical and Electronics Engineers (IEEE) 802.11 series of protocols utilized by a WLAN, such as 802.11a / b / g, 802.11n, 802.11ac, 802.11ax, or 802.11be. The methods provided in this application may be implemented by a communication device in a wireless communication system, or a chip or processor in the communication device. Correspondingly, the communication device supports communication according to the IEEE 802.11 series of protocols.

[0153] In order to facilitate understanding of the embodiments of this application, the communication system shown in FIG. 1 is first used as an example to describe in detail the communication system applicable to the embodiments of this application.

[0154] The scenario system shown in Fig. 1 may be a WLAN system. The WLAN system in Fig. 1 may include one or more access point (AP) stations and one or more non-access point stations (non-AP STAs). For ease of explanation, in this specification, the access point stations are referred to as access points (APs) and the non-access point stations are referred to as stations (STAs). The APs are, for example, AP#1 and AP#2 in Fig. 1, and the STAs are, for example, STA#1 and STA#2 in Fig. 1.

[0155] An AP may be an access point used by terminal devices (such as mobile phones) to access a wired (or wireless) network, and is mainly deployed in a house, a building, or a park. The typical coverage radius is from tens of meters to hundreds of meters. Of course, an access point may alternatively be deployed outdoors. An access point is equivalent to a bridge that connects wired and wireless networks. The main function of an access point is to connect various wireless network clients together, and then connect the wireless network to Ethernet. In particular, an AP may be a terminal device (such as a mobile phone) or a network device (such as a router) with a wireless-fidelity (Wi-Fi) chip. An access point may be a device that supports the 802.11be standard and the 802.11be next-generation standard. The access point may alternatively be a device that supports multiple WLAN standards in the 802.11 family, such as 802.11ax, 802.11ac, 802.11n, 802.11g, 802.11b, and 802.11a.

[0156] The access point may include a processor, a transmitter, and a receiver. The processor is configured to control and manage operation of the access point. The transmitter is configured to transmit information. The receiver is configured to receive information.

[0157] The STA may be a wireless communication chip, a wireless sensor, a wireless communication terminal, etc., and may be referred to as a user terminal. For example, the station may be a mobile phone supporting a Wi-Fi communication function, a tablet computer supporting a Wi-Fi communication function, a set-top box supporting a Wi-Fi communication function, a smart TV supporting a Wi-Fi communication function, an intelligent wearable device supporting a Wi-Fi communication function, an in-vehicle communication device supporting a Wi-Fi communication function, or a computer supporting a Wi-Fi communication function. Optionally, the station may support the 802.11be standard and the 802.11be next-generation standard. Alternatively, the station may support multiple WLAN standards of the 802.11be family, such as 802.11ax, 802.11ac, 802.11n, 802.11g, 802.11b, and 802.11a.

[0158] The STA may include a processor, a transmitter, and a receiver. The processor is configured to control and manage the operation of the access point. The transmitter is configured to transmit information. The receiver is configured to receive information.

[0159] For example, APs and STAs may be devices used in the Internet of Things (IoT), such as Internet of Vehicles, Internet of Things nodes, or sensors; in smart homes, such as smart cameras, smart remote controls, or smart water or electricity meters; and in smart cities, such as sensors.

[0160] The access point and the station in the embodiment of this application may also be collectively referred to as a communication device. The communication device may include a hardware structure and a software module, and the above functions are implemented in the form of a hardware structure, a software module, or a combination of a hardware structure and a software module. Some of the above functions may be implemented in the form of a hardware structure, a software module, or a combination of a hardware structure and a software module.

[0161] 2 is a schematic diagram of a structure of a communication device according to an embodiment of this application. As shown in FIG. 2, a communication device 200 may include a processor 201 and a transceiver 205, and optionally further includes a memory 202. The communication device may be used as a device for transmitting a trigger frame and a PPDU in this application, or may be used as a device for receiving a trigger frame and a PPDU in this application.

[0162] The transceiver 205 may be referred to as a transceiver unit, a transceiver machine, a transceiver circuit, etc., and is configured to implement a transceiver function. The transceiver 205 may include a receiver and a transmitter. The receiver may be referred to as a receiver machine, a receiver circuit, etc., and is configured to implement a receiving function. The transmitter may be referred to as a transmitter machine, a transmitter circuit, etc., and is configured to implement a transmitting function.

[0163] The memory 202 may store computer programs, software codes, or instructions 204, which may also be referred to as firmware. The processor 201 may control the MAC layer and the PHY layer by executing the computer programs, software codes, or instructions 203 in the processor 201 or by calling the computer programs, software codes, or instructions 204 stored in the memory 202 to implement the methods for transmitting PPDUs provided in the following embodiments of this application. The processor 201 may be a central processing unit (CPU), and the memory 202 may be, for example, a read-only memory (ROM) or a random access memory (RAM).

[0164] The processor 201 and transceiver 205 described in this application may be implemented in an integrated circuit (IC), an analog IC, a radio frequency integrated circuit (RFIC), a mixed signal IC, an application specific integrated circuit (ASIC), a printed circuit board (PCB), or an electronic device, etc.

[0165] The communication device 200 may further include an antenna 206. The modules included in the communication device 200 are merely illustrative examples and are not limiting in this application.

[0166] As described above, the communication device 200 described in the above embodiment may be an AP or a STA. However, the scope of the communication device described in this application is not limited thereto, and the communication device may not be limited to the structure shown in FIG.

[0167] An AP may have multiple antennas / radio frequencies or a single antenna / radio frequency. The antenna / radio frequency is used to transmit / receive data packets. In some implementations, the antenna or radio frequency part of the AP may be separate, i.e., located away, from the body of the AP. In some implementations, a STA may have a single antenna / radio frequency or multiple antennas / radio frequencies and may be a device with two or more antennas. The antenna / radio frequency is used to transmit / receive data packets. In some implementations, the antenna or radio frequency part of the STA may be separate, i.e., located away, from the body of the STA.

[0168] The communication device in this application may alternatively be an independent device or part of a larger device. For example, the communication device may be implemented in the following forms: (1) an independent integrated circuit IC, chip, chip system, or subsystem; (2) a set including one or more ICs, where optionally the set of ICs may also include a storage component for storing data and instructions; (3) a module that may be embedded in other devices; (4) a receiver, an intelligent terminal, a wireless device, a handheld device, a mobile unit, an in-vehicle device, a cloud device, an artificial intelligence device, or the like; or (5) others.

[0169] For the communication device implemented in the form of a chip or chip system, please refer to the schematic diagram of the chip structure shown in Figure 3. The chip shown in Figure 3 includes a processor 301 and an interface 302. There may be one or more processors 301 and there may be multiple interfaces 302. The interface 302 is configured to transmit or receive signals. Optionally, the chip or chip system may include a memory 303. The memory 303 is configured to store program instructions and data required for the chip or chip system.

[0170] The embodiments of this application do not limit the scope of protection and applicability of the claims. Those skilled in the art may adaptively change the functions and arrangements of elements in this application, and may omit, replace, or add various processes or components as appropriate without departing from the scope of the embodiments of this application.

[0171] Orthogonal frequency division multiple access (OFDMA) may be utilized between the AP and the STA. In an OFDMA transmission scenario, a WLAN protocol divides the entire bandwidth into several resource units (RUs), and a PPDU may be transmitted between the AP and the STA on the assigned RU. According to the 802.11ax standard, for a bandwidth of 20 MHz, 40 MHz, 80 MHz, or 160 MHz, the bandwidth may be divided into multiple types of RUs of various sizes, i.e., 26-tone RU, 52-tone RU, 106-tone RU, 242-tone RU, 484-tone RU, or 996-tone RU, etc. Here, a tone represents a subcarrier. For example, a 26-tone RU represents an RU that includes 26 consecutive subcarriers, or an RU that includes a group of 13 consecutive subcarriers and another group of 13 consecutive subcarriers.

[0172] The resource allocation scheme in which the bandwidth is divided into several resource units is still used in the 802.11be standard. In the 802.11be standard, the positions of some data subcarriers and pilot subcarriers are changed based on the 802.11ax standard. For the cases of 20 MHz, 40 MHz, 80 MHz, 160 MHz, and 320 MHz, the spectrum bandwidth can be divided into several types of RUs with various sizes, namely, 26-tone RU, 52-tone RU, 106-tone RU, 242-tone RU, 484-tone RU, and 996-tone RU, etc. The 26-tone RU can be assigned to one STA to be used. In general, RUs with 242 tones or more can be assigned to one or more STAs to be used. The RUs on the bandwidth include data subcarriers and pilot subcarriers. The data subcarriers are used to carry data information. The pilot subcarriers transmit fixed values ​​and are used by the receiving end to estimate the phase and perform phase correction.

[0173] When the bandwidth is 20 MHz, as shown in FIG. 4, FIG. 4 is a schematic diagram of possible resource unit allocation schemes in the case of 20 MHz bandwidth. The entire 20 MHz bandwidth may include the entire 242-tone RU, or may include various combinations of 26-tone RU, 52-tone RU, or 106-tone RU. In addition to the RU for data transmission, some guard subcarriers, null subcarriers, or direct current (DC) subcarriers are further included.

[0174] When the bandwidth is 40 MHz, Figure 5 is a schematic diagram of possible resource unit allocation schemes in the 40 MHz case. The entire bandwidth is approximately equivalent to replicating the 20 MHz tone plan. The entire 40 MHz bandwidth may include the entire 484 tone RU, or various combinations of 26 tone RU, 52 tone RU, 106 tone RU, or 242 tone RU.

[0175] Figure 6 is a schematic diagram of a possible resource unit allocation scheme in the case of 80 MHz bandwidth. When the channel bandwidth is 80 MHz, the entire bandwidth is approximately equivalent to two copies of the 40 MHz tone plan. The entire 80 MHz bandwidth may include the entire 996-tone RU, or may include various combinations of 484-tone RU, 242-tone RU, 106-tone RU, 52-tone RU, or 26-tone RU.

[0176] When the bandwidth is 160 MHz or 80 MHz+80 MHz, the entire bandwidth can be considered as two copies of the 80 MHz tone plan. The entire bandwidth may include the entire 2×996 tone RU, or may include various combinations of 26-tone RUs, 52-tone RUs, 106-tone RUs, 242-tone RUs, 484-tone RUs, or 996-tone RUs. A 2×996 tone RU is an RU that contains two consecutive 996-tone RU subcarriers.

[0177] Similarly, when the bandwidth is 320 MHz, the entire bandwidth can be considered as two copies of the 160 MHz tone plan. The entire bandwidth may include the full 4×996 tone RUs, or may include various combinations of 26 tone RUs, 52 tone RUs, 106 tone RUs, 242 tone RUs, 484 tone RUs, or 996 tone RUs.

[0178] The 26-tone RU, 52-tone RU, 106-tone RU, 242-tone RU, and 484-tone RU are RUs that include multiple consecutive subcarriers or RUs that include two consecutive subcarrier groups (e.g., the fifth 26-tone RU in the first row of FIG. 4 includes two 13-tones and the seven DC tones in the middle). In this application, such RUs may be considered as consecutive RUs.

[0179] Currently, there is a low power indoor (LPI) communication scheme, which imposes strict constraints on the maximum transmission power and maximum frequency spectral density. The transmission power of a device is limited by both the maximum power and the maximum power spectral density. The transmission power cannot exceed the maximum power, and the transmission power spectral density cannot exceed the maximum power spectral density. Since the transmission power of a device = power spectral density x transmission bandwidth, when the power spectral density is specified, the maximum transmission power of a device increases with the increase of the transmission bandwidth. It is known that the average transmission power of each subcarrier = transmission power / number of effective subcarriers. Therefore, when the power spectral density is specified, the transmission power may be increased to increase the average transmission power of each subcarrier, and the transmission bandwidth may be increased to increase the transmission power.

[0180] In one scheme, subcarriers on one consecutive RU may be distributed discretely to multiple consecutive RUs for transmission. For example, considering that one consecutive 26-tone RU (denoted as consecutive RU#1) is assigned to a user, the subcarriers of consecutive RU#1 may be distributed discretely to two consecutive 26-tone RUs for transmission. For example, 13 subcarriers at even-numbered positions are selected on consecutive RU#1, and subcarriers at odd-numbered positions are selected on another consecutive 26-tone RU (denoted as consecutive RU#2). The RU formed by the 13 subcarriers at even-numbered positions on consecutive RU#1 and the 13 subcarriers at odd-numbered positions on consecutive RU#2 may be referred to as a distributed RU. It may be understood that under the same power spectral density, the transmission bandwidth of the distributed RU is twice that of the consecutive RU, and the transmission power is also doubled. However, the number of subcarriers is still 26, and therefore the average power on each subcarrier is doubled.

[0181] However, this causes a problem that the original method of transmitting LTF on consecutive RUs is no longer applicable to distributed RUs. Specifically, after consecutive RUs are assigned to a user, the user transmits data and LTF on all subcarriers of the consecutive RUs. In this transmission method, the PAPR of the LTF is taken into consideration when designing an LTF sequence, so that this transmission method can guarantee the PAPR of the LTF. However, since the subcarriers included in the distributed RUs are not consecutive, and the number of subcarriers included in the distributed RUs is not necessarily equal to the number of subcarriers included in the consecutive RUs, when the LTF obtained by using the existing LTF sequence is transmitted on all subcarriers of the distributed RUs, the PAPR of the LTF cannot be guaranteed.

[0182] In this respect, the present application provides a method for transmitting PPDU to increase data transmission power and guarantee the PAPR of the LTF, thereby ensuring system performance.

[0183] Before describing the methods provided in this application, the relevant concepts in this application will first be described.

[0184] 1. Continuous RU (CRU) A contiguous RU is an RU that includes multiple contiguous subcarriers, or a contiguous RU is an RU that includes two contiguous subcarrier groups. The multiple subcarriers included in each contiguous subcarrier group are contiguous. The two contiguous subcarrier groups are spaced apart only by one or more of guard subcarriers, null subcarriers, or DC subcarriers. All RUs supported by 802.11ax may be understood as contiguous RUs. It should be understood that contiguous RUs may also have other names, e.g., regular RUs. The name of contiguous RUs is not limited in this application.

[0185] It should be understood that a contiguous RU may include multiple contiguous subcarriers, a contiguous RU may include two contiguous subcarrier groups, and the two contiguous subcarrier groups are non-contiguous. For example, a 26-tone RU including a group of 13 contiguous subcarriers and another group of 13 contiguous subcarriers is a contiguous RU. Similarly, a 996-tone RU including a group of 484 contiguous subcarriers and another group of 484 contiguous subcarriers is a contiguous RU. Such RUs may be referred to as special contiguous RUs or generalized contiguous RUs. In this application, contiguous RUs include special contiguous RUs and generalized contiguous RUs.

[0186] In this application, consecutive RUs that include K subcarriers are referred to as consecutive K-tone RUs. For example, consecutive 26-tone RUs are consecutive RUs that include 26 subcarriers. In other words, the concept of consecutive K-tone RUs is the same as the concept of K-tone RUs in the existing 802.11ax standard.

[0187] 2. Distribute RU (DRU) A distributed RU includes multiple subcarrier groups that are distributed in the frequency domain. In other words, a distributed RU includes multiple subcarrier groups, and any two subcarrier groups are distributed in the frequency domain. A subcarrier group includes one subcarrier, or a subcarrier group includes at least two consecutive subcarriers. In other words, a subcarrier group includes one subcarrier or includes multiple consecutive subcarriers. A distributed RU may also be referred to as a discontinuous RU (DRU). Of course, in other embodiments, a distributed RU may have other names. The name of a distributed RU is not limited in this application. In this application, the number of subcarrier groups included in one distributed RU is two or more.

[0188] In this application, a distributed RU that includes K subcarriers is referred to as a distributed K-tone RU. For example, a distributed 26-tone RU refers to a distributed RU that includes 26 subcarriers. For the value of K, refer to the value of K used for consecutive RUs. Of course, the value of K may be different from the value of K used for consecutive RUs. For example, when the bandwidth is 20 MHz, the 20 MHz may include at least one or more combinations of distributed 26-tone RUs, distributed 52-tone RUs, distributed 106-tone RUs, or distributed 242-tone RUs.

[0189] In this application, one distributed RU and another distributed RU may form a distributed multi-RU (MRU), and a distributed MRU may be assigned to one or more stations. For example, a distributed 242-tone RU and a distributed 484-tone RU may form a distributed 484+242-tone RU.

[0190] It should be noted that the above mentioned special contiguous RU or generalized contiguous RU does not belong to distributed RU in this embodiment of this application. For example, in the above example, a 26-tone RU including a group of 13 contiguous subcarriers and another group of 13 contiguous subcarriers is not a distributed RU as defined in this application, but a special contiguous RU.

[0191] In some examples, the number of subcarriers included in any two of the multiple subcarrier groups included in a distributed RU may be the same or different. For example, the number of subcarriers in each subcarrier group may be 1. In other examples, the number of subcarriers in some subcarrier groups is 1, and the number of subcarriers in other subcarrier groups is 2. In other words, one distributed RU may include four subcarrier groups, and the numbers of subcarriers in the four subcarrier groups may be 1, 1, 2, and 2, respectively.

[0192] In some examples, when the number of subcarrier groups included in a distributed RU is 3 or more, the number of subcarriers between every two adjacent subcarrier groups in the distributed subcarrier groups included in the distributed RU may be the same or different, and every two adjacent subcarrier groups refer to two adjacent subcarrier groups in one distributed RU.

[0193] For example, for a distributed RU including three distributed subcarrier groups (denoted as subcarrier group #1, subcarrier group #2, and subcarrier group #3), subcarrier group #1 is adjacent to subcarrier group #2, which is adjacent to subcarrier group #3. In other words, the frequency of the subcarriers included in subcarrier group #1 is lower than the frequency of the subcarriers included in subcarrier group #2, which is lower than the frequency of the subcarriers included in subcarrier group #3. In addition, the subcarrier with the maximum frequency in subcarrier group #1 and the subcarrier with the minimum frequency in subcarrier group #2 are discontinuous in frequency (or frequency domain). In other words, there are K1 (K1≧1) subcarriers to separate the two subcarriers, or there are also K1 subcarriers between the two subcarriers. The subcarrier with the maximum frequency in subcarrier group #2 and the subcarrier with the minimum frequency in subcarrier group #3 are discontinuous in frequency (or frequency domain). In other words, there are K2 (K2≧1) subcarriers to separate the two subcarriers, or there are also K2 subcarriers between the two subcarriers. K1 may or may not be equal to K2.

[0194] In another example, for a distributed RU that includes four distributed subcarrier groups (denoted as subcarrier group #1, subcarrier group #2, subcarrier group #3, and subcarrier group #4), subcarrier group #1 is adjacent to subcarrier group #2, which is adjacent to subcarrier group #3, which is adjacent to subcarrier group #4. In addition, the subcarrier with the highest frequency in subcarrier group #1 and the subcarrier with the lowest frequency in subcarrier group #2 are separated by K1 (K1≧1) subcarriers. The subcarrier with the highest frequency in subcarrier group #2 and the subcarrier with the lowest frequency in subcarrier group #3 are separated by K2 (K2≧1) subcarriers. The subcarrier with the highest frequency in subcarrier group #3 and the subcarrier with the lowest frequency in subcarrier group #4 are separated by K3 (K3≧1) subcarriers. Two or three of K1, K2, and K3 are equal, or any two of them are unequal.

[0195] For example, Figure 7 is a schematic diagram of a distributed RU. As shown in Figure 7, a distributed 26-tone RU is distributed within a 40 MHz frequency range. The distributed 26-tone RU includes 13 subcarriers in a first 20 MHz frequency range and 13 subcarriers in a second 20 MHz frequency range.

[0196] For example, Figure 8 is a schematic diagram of a distributed RU. As shown in Figure 8, the distributed 52-tone RU is distributed within a 20 MHz frequency range. The distributed 52-tone RU includes 26 subcarriers in a first contiguous 52-tone RU and 26 subcarriers in a third contiguous 52-tone RU in the first 20 MHz frequency range.

[0197] For example, Figure 9 is a schematic diagram of a distributed RU. As shown in Figure 9, the distributed 52-tone RU is distributed within an 80 MHz frequency range. The distributed 52-tone RU includes 13 subcarriers in a first contiguous 52-tone RU in a first 20 MHz frequency range, 13 subcarriers in a first contiguous 52-tone RU in a second 20 MHz frequency range, 13 subcarriers in a first contiguous 52-tone RU in a third 20 MHz frequency range, and 13 subcarriers in a first contiguous 52-tone RU in a fourth 20 MHz frequency range.

[0198] Optionally, the distributed RU includes K subcarriers. The number of 1 MHz bands occupied by the distributed RU is greater than the number of 1 MHz bands occupied by the RU that includes K subcarriers. The minimum granularity of the number of 1 MHz bands is 1.

[0199] The number of 1 MHz bands occupied by a distributed RU is the number of 1 MHz bands occupied by the K subcarriers in the distributed RU. The bandwidth includes multiple 1 MHz bands. At least one subcarrier of a distributed RU is distributed onto one 1 MHz band. Even if the subcarriers of a distributed RU do not completely occupy one 1 MHz band, one 1 MHz band is counted in the number of 1 MHz bands occupied by a distributed RU.

[0200] For example, the 26 subcarriers in a distributed 26-tone RU include four subcarrier groups: in ascending frequency order, the 1st to 7th subcarriers are consecutive and form one subcarrier group, the 8th to 14th subcarriers are consecutive and form one subcarrier group, the 15th to 20th subcarriers are consecutive and form one subcarrier group, and the 21st to 26th subcarriers are consecutive and form one subcarrier group.

[0201] In one 1 MHz band occupied by the 1st to 7th subcarriers, only 7 subcarriers are subcarriers within the distributed 26-tone RU. Even if the frequency corresponding to the 1st to 7th subcarriers is only 0.5 MHz, in other words, even if the 1st to 7th subcarriers do not completely occupy the 1 MHz band, the number of 1 MHz bands occupied by the 1st to 7th subcarriers is also 1 MHz bands because the minimum granularity of the number of 1 MHz bands is 1.

[0202] Similarly, in one 1 MHz band occupied by the 8th to 14th subcarriers, only 7 subcarriers are subcarriers in the distributed 26-tone RU, and the number of 1 MHz bands occupied by the 8th to 14th subcarriers is also one 1 MHz band. In one 1 MHz band occupied by the 15th to 20th subcarriers, only 7 subcarriers are subcarriers in the distributed 26-tone RU, and the number of 1 MHz bands occupied by the 15th to 20th subcarriers is also one 1 MHz band. In one 1 MHz band occupied by the 21st to 26th subcarriers, only 7 subcarriers are subcarriers in the distributed 26-tone RU, and the number of 1 MHz bands occupied by the 21st to 26th subcarriers is also one 1 MHz band. Thus, the number of 1 MHz bands occupied by distributed 26-tone RUs is four 1 MHz bands.

[0203] It can be understood from the above description that the tone plan of an RU is different from that of a distributed RU. For an RU, there is a fixed correspondence between the number of subcarriers and the number of 1 MHz bands occupied by the subcarriers. For example, the number of 1 MHz bands occupied by 26 subcarriers in a contiguous 26-tone RU is 2, the number of 1 MHz bands occupied by 52 subcarriers in a contiguous 52-tone RU is 4, ..., the number of 1 MHz bands occupied by 242 subcarriers in a contiguous 242-tone RU is 20, the number of 1 MHz bands occupied by a contiguous 484-tone RU is 40, and the number of 1 MHz bands occupied by a contiguous 996-tone RU is 80. However, for a distributed RU, there is no fixed correspondence between the number of subcarriers in a distributed RU and the number of 1 MHz bands occupied by the subcarriers. For example, the 996 subcarriers in a distributed 996-tone RU may be discretely distributed on a 160 MHz bandwidth or may be discretely distributed on a 320 MHz bandwidth. In other words, the number of 1 MHz bands occupied by the 996 subcarriers in a distributed 996-tone RU may be 160 or 320.

[0204] 3. Correspondence between distributed RUs and continuous RUs A plurality of consecutive RUs corresponding to one distributed RU are a plurality of consecutive RUs including all subcarriers included in the distributed RU and including a minimum number of subcarriers. Any one of the plurality of consecutive RUs corresponding to one distributed RU includes a portion of the subcarriers of the distributed RU.

[0205] It should be understood that one distributed RU corresponding to multiple consecutive RUs can be described as follows: one distributed RU occupies multiple consecutive RUs, or one distributed RU is within multiple consecutive RUs, or one distributed RU has a mapping relationship with multiple consecutive RUs, or multiple consecutive RUs are the consecutive RUs in which one distributed RU is located.

[0206] For example, the distributed RUs shown in FIG. 7 are used as an example. As shown in FIG. 7, the first consecutive 26-tone RU, the first consecutive 52-tone RU, the first consecutive 106-tone RU, the first consecutive 242-tone RU, and the first consecutive 484-tone RU in the first 20 MHz are respectively represented as consecutive RU#1, consecutive RU#2, consecutive RU#3, consecutive RU#4, and consecutive RU#5. The first consecutive 26-tone RU, the first consecutive 52-tone RU, the first consecutive 106-tone RU, the first consecutive 242-tone RU, and the first consecutive 484-tone RU in the second 20 MHz are respectively represented as consecutive RU#6, consecutive RU#7, consecutive RU#8, consecutive RU#9, and consecutive RU#10. Any one of the consecutive RUs #1 to #5 includes some subcarriers of the distributed 26-tone RU shown in FIG. 7. Any one of the consecutive RUs #6 to #10 includes other subcarriers of the distributed 26-tone RU. In other words, the multiple consecutive RUs that include all the subcarriers of a distributed RU are any consecutive RU in consecutive RU #1 to consecutive RU #5, and any consecutive RU in consecutive RU #6 to consecutive RU #10. In a combination that includes one consecutive RU in consecutive RU #1 to consecutive RU #5 and one consecutive RU in consecutive RU #6 to consecutive RU #10, consecutive RU #1 and consecutive RU #6 include a total of 52 subcarriers. The total number of subcarriers included in two consecutive RUs in combinations other than that combination is greater than 52. In other words, consecutive RU #1 and consecutive RU #6 are multiple consecutive RUs that include the smallest total number of subcarriers and are included in the multiple consecutive RUs that include all the subcarriers of a distributed RU. Therefore, the multiple consecutive RUs corresponding to a distributed 26-tone RU are consecutive RU #1 and consecutive RU #6.

[0207] In this application, a distributed RU is referred to as corresponding to consecutive RU #1 and consecutive RU #6, or a distributed RU is referred to as a distributed RU having a mapping relationship with consecutive RU #1 and consecutive RU #6, or consecutive RU #1 and consecutive RU #6 are referred to as consecutive RUs occupied by the distributed RU.

[0208] For other examples, the distributed RUs shown in FIG. 8 are used as examples. The first consecutive 52-tone RU, the first consecutive 106-tone RU, the third consecutive 52-tone RU, and the second consecutive 106-tone RU in the first 20 MHz shown in FIG. 8 are denoted as consecutive RU#1, consecutive RU#2, consecutive RU#3, and consecutive RU#4, respectively. Both consecutive RU#1 and consecutive RU#2 include some subcarriers of the distributed 52-tone RU shown in FIG. 8, and both consecutive RU#3 and consecutive RU#4 include other subcarriers of the distributed 52-tone RU. In other words, the multiple consecutive RUs including all subcarriers of the distributed RU are consecutive RU#1 and consecutive RU#3, consecutive RU#2 and consecutive RU#3, consecutive RU#1 and consecutive RU#4, or consecutive RU#2 and consecutive RU#4. In the above four combinations, consecutive RU#1 and consecutive RU#3 include a total of 52 subcarriers, and the total number of subcarriers included in any one of the other three combinations is greater than 52. In other words, consecutive RU#1 and consecutive RU#3 are consecutive RUs within the consecutive RUs that include the smallest total number of subcarriers and include all subcarriers of the distributed RU. Thus, the consecutive RUs corresponding to the distributed 52-tone RU are consecutive RU#1 and consecutive RU#3. In this application, the distributed RU is referred to as corresponding to consecutive RU#1 and consecutive RU#3, or the distributed RU is referred to as a distributed RU having a mapping relationship with consecutive RU#1 and consecutive RU#3, or consecutive RU#1 and consecutive RU#3 are referred to as consecutive RUs occupied by the distributed RU.

[0209] For another example, the distributed RU shown in FIG. 9 is used as an example. The multiple consecutive RUs in the multiple consecutive RUs that include the minimum total number of subcarriers and include all subcarriers of the distributed 52-tone RU are the first consecutive 52-tone RU (contiguous RU#1) in the first 20 MHz, the first consecutive 52-tone RU (contiguous RU#2) in the second 20 MHz, the first consecutive 52-tone RU (contiguous RU#3) in the third 20 MHz, and the first consecutive 52-tone RU (contiguous RU#4) in the fourth 20 MHz. Therefore, the multiple consecutive RUs corresponding to the distributed 52-tone RU are consecutive RU#1, consecutive RU#2, consecutive RU#3, and consecutive RU#4. In this application, the distributed 52-tone RU is referred to as corresponding to consecutive RU#1 to consecutive RU#4, or the distributed RU is referred to as a distributed RU having a mapping relationship with consecutive RU#1 to consecutive RU#4, or consecutive RU#1 to consecutive RU#4 are referred to as consecutive RUs occupied by the distributed RU.

[0210] The method for transmitting PPDU provided in this application will be described in detail below with reference to the accompanying drawings. It should be understood that the technical solution of this application can be applied to a wireless communication system, for example, the communication system shown in Fig. 1. There may be a wireless communication connection relationship between two communication devices in the wireless communication system. One of the two communication devices may correspond to the AP shown in Fig. 1, or may be a chip disposed in the AP. The other communication device may correspond to the STA shown in Fig. 1, or may be a chip disposed in the STA.

[0211] 10 is a schematic flow chart of a method 1000 for transmitting a PPDU according to an embodiment of this application. The steps shown in FIG. 10 are described below.

[0212] S1010: The AP transmits a trigger frame.

[0213] The trigger frame is used to trigger at least one STA, which is denoted as STA#1 to STA#N in the figure, to transmit an uplink PPDU.u In other words, the trigger frame is to trigger N u In response, at least one STA may receive the trigger frame and transmit a respective PPDU based on the trigger frame.

[0214] The trigger frame may include resource allocation information utilized by at least one STA to transmit the PPDU. Each STA may know about the at least one distributed RU that is assigned to it based on the STA's resource allocation information.

[0215] In a possible implementation, the resource allocation information is information about the at least one distributed RU. In other words, the at least one distributed RU may be directly indicated by the resource allocation information. How to directly indicate the at least one distributed RU is not limited in this application. For example, the resource allocation information is an index of the at least one distributed RU.

[0216] In another possible implementation, the resource allocation information is information about at least one consecutive RU corresponding to the at least one distributed RU. The STA may know the at least one consecutive RU based on the resource allocation information, and may further know the allocated distributed RU based on the correspondence between the at least one distributed RU and the at least one consecutive RU. In other words, the at least one distributed RU may be indirectly indicated by the resource allocation information. The correspondence between the distributed RU and the consecutive RU may be defined in a protocol, may be configured by the AP, or may be negotiated by the AP and the STA. This is not limited in this application.

[0217] For example, the resource allocation information may be carried in a resource unit allocation subfield (RU Allocation subfield) in a user information field in the trigger frame.

[0218] Fig. 11 shows an example of the frame structure of a trigger frame. Fig. 11(a) shows another example of the frame structure of a trigger frame. As shown in Fig. 11 and Fig. 11(a), the trigger frame includes a common information field and a user information list field.

[0219] The common information field includes common information that needs to be read by at least one STA triggered by the trigger frame. In the common field, one bit indicates whether distributed RUs are used in the data portion, and the bit may use a reserved bit.

[0220] The user information list field includes at least one user information field. The at least one user information field has one-to-one correspondence with at least one STA. In the user information field, an association identifier (AID12) indicates an association identifier of the STA corresponding to the user information field, and may be an address of the STA, etc. A resource unit allocation subfield (RU Allocation subfield) indicates resource allocation information of the STA indicated by AID12, for example, information about distributed RUs or information about consecutive RUs allocated to the STA. After receiving the trigger frame, the STA can analyze the trigger frame to obtain the user information field that matches the AID12 of the STA, and thereby determine the allocated distributed RUs based on the resource unit allocation subfield in the user information field.

[0221] Figure 11(b) shows the configuration of the common field in the trigger frame shown in Figure 11(a). The common field mainly includes: Trigger Type: The trigger type field is 4 bits and currently includes basic type, Beamforming report poll, Multi-user Block Ack Request (MU-BAR), Multi-user request to send (MU-RTS), Buffer status report poll, Group cast retransmission Multi-user Block Ack Request (GCR MU-BAR), Bandwidth query report poll, and NDP feedback report poll.

[0222] Uplink Bandwidth: The Uplink Bandwidth field indicates the bandwidth in the HE-SIG-A of the HE TB PPDU.

[0223] Number of EHT-LTF symbols and midamble periodicity: The number of EHT-LTF symbols and midamble periodicity fields need to be combined with the Doppler field for indication. Specifically, when the Doppler field is 0, the number of EHT-LTF symbols is indicated as follows: value 0 indicates 1 EHT-LTF symbol, value 1 indicates 2 EHT-LTF symbols, value 2 indicates 4 EHT-LTF symbols, value 3 indicates 6 EHT-LTF symbols, value 4 indicates 8 EHT-LTF symbols, and other values ​​indicate reserved.

[0224] When the Doppler field is 1, the first two bits indicate the number of HE-LTF symbols, and the third bit indicates the midamble periodicity. Specifically, a value of 0 for the first two bits indicates one HE-LTF symbol; a value of 1 for one of the first two bits indicates two HE-LTF symbols; a value of 2 for the first two bits indicates four HE-LTF symbols; and a value of 3 for the first two bits indicates unused. The third bit indicates whether the midamble periodicity is 10 or 20 symbols.

[0225] Figure 11(c) shows the configuration of the user information field in the trigger frame shown in Figure 11(a). The user information field mainly includes the following: Resource Unit Allocation: The resource unit allocation field may be combined with the uplink bandwidth field in the common information field to indicate the size and location of the assigned RUs.

[0226] Uplink Forward Error Correction Coding Type: The uplink forward error correction coding type field may indicate the coding type (LDPC or BCC) of the requested EHT TB PPDU.

[0227] Modulation and coding scheme: The modulation and coding scheme field indicates the EHT-MCS for the data portion of the requested EHT TB PPDU.

[0228] Spatial Stream Allocation / Random Access RU Information: If AID is 0 or 2045, it indicates the RA-RU Information subfield, otherwise it indicates the Spatial Stream Allocation subfield. In this case, 4 bits indicate the spatial stream starting sequence number, and 2 bits indicate the number of spatial streams. The Spatial Stream Allocation / Random Access RU Information field specifically includes a Starting Spatial Stream subfield and a Number Of Spatial Stream subfield.

[0229] In addition, in some instances, the contents of other fields in Figure 11 and Figure 11(a) are described in the prior art, and the details will not be described again here.

[0230] S1020: At least one STA individually transmits a respective PPDU to the AP based on the trigger frame. In response, the AP receives at least one PPDU transmitted by the at least one STA, and one STA transmits one PPDU.

[0231] The PPDU includes a data field and an LTF that is used for channel estimation.

[0232] The content of the data field is data information. The data field (or the data information in the data field) is carried in at least one distributed RU allocated by the AP.

[0233] The content in the LTF is the LTF transmission sequence. The LTF (or the LTF transmission sequence in the LTF) is carried on all subcarriers in the first transmission bandwidth. It should be understood that the LTF transmission sequence refers to the LTF sequence transmitted by the STA, and is not the LTF sequence (or the value of the LTF sequence) that is not processed, i.e., is not the LTF sequence specified in the protocol.

[0234] The first transmission bandwidth is a bandwidth corresponding to a distributed RU allocated by the AP to at least one STA for transmitting an uplink PPDU. Alternatively, the first transmission bandwidth is a bandwidth allocated by the AP to the uplink PPDU. In a scenario where all RUs included in the entire bandwidth are distributed RUs, or in a scenario where resource allocation is performed on the entire bandwidth using distributed RUs, the first transmission bandwidth is the entire bandwidth. In a scenario where the entire bandwidth includes both distributed RUs and contiguous RUs, or in a scenario where resource allocation is performed on some bandwidths within the entire bandwidth using distributed RUs and on other bandwidths using contiguous RUs, the first transmission bandwidth is a bandwidth corresponding to the distributed RUs. For example, assume that the entire bandwidth is 40 MHz. In a scenario where resource allocation is performed on the 40 MHz bandwidth using distributed RUs, the first transmission bandwidth is 40 MHz. In a scenario where resource allocation is performed on a 20 MHz bandwidth within the 40 MHz bandwidth using distributed RUs and on another 20 MHz bandwidth using contiguous RUs, the first transmission bandwidth is 20 MHz.

[0235] It should be understood that the first transmission bandwidth is notified to at least one STA by using a trigger frame, and the specific notification manner is not limited in this application.

[0236] It should be understood that the distributed RU carrying the data field may be one RU or multiple RUs. In addition, regardless of which distributed RU or distributed RUs in the first transmission bandwidth are the distributed RU carrying the data field, the bandwidth occupied by the distributed RU is the first transmission bandwidth. For example, when the distributed RUs carrying the data field are distributed RU#1 and distributed RU#2, the bandwidth occupied by distributed RU#1 and distributed RU#2 is the first transmission bandwidth. When the distributed RUs carrying the data field are distributed RU#3 and distributed RU#4, the bandwidth occupied by distributed RU#3 and distributed RU#4 is still the first transmission bandwidth. In this application, the PPDU may be any one of the following PPDUs: high throughput (HT) PPDU, very high throughput (VHT) PPDU, high efficiency (HE) PPDU, or extremely high throughput (EHT) PPDU. Alternatively, the PPDU may be a PPDU in another protocol that may appear in the future.

[0237] Correspondingly, the LTF may be the LTF in the corresponding PPDU, the LTF in the HT PPDU is the HT-LTF, the LTF in the VHT PPDU is the VHT-LTF, the LTF in the HE PPDU is the HE-LTF, and the LTF in the EHT PPDU is the EHT-LTF.

[0238] An example in which the PPDU is an EHT PPDU is used to briefly explain the format of the EHT PPDU.

[0239] Please refer to Figure 12. Figure 12 is a schematic diagram of the format of EHT PPDU. The names and simple functions of the fields (or referred to as fields) of EHT PPDU are shown in Table 1 below. The Data field is the data field in this application. It should be understood that the EHT PPDU is just an example, and the specific format of the EHT PPDU is to be determined by the standard. PE is an optional field.

[0240] [Table 1]

[0241] In the prior art, when a PPDU is transmitted in a first transmission bandwidth, both the data field and the LTF in the PPDU are carried on all subcarriers in the first transmission bandwidth. Since the LTF carried on all subcarriers in the first transmission bandwidth is designed, the PAPR of the LTF can be guaranteed. According to the method for transmitting a PPDU provided in this application, the data is carried on distributed RUs assigned to the STA, and the LTF is carried on all subcarriers in the first transmission bandwidth (i.e., all subcarriers corresponding to all distributed RUs assigned to at least one STA and in a trigger frame) instead of the distributed RUs assigned to the STA. Therefore, it can be guaranteed that the average power of the data portion transmitted by the AP is increased, and the PAPR of the LTF can be guaranteed, thereby ensuring system performance.

[0242] Optionally, before S1020, the method may further include: at least one STA individually obtaining an LTF to be transmitted by the at least one STA based on the value of the LTF sequence (or the LTF sequence) and the matrix P.

[0243] In other words, for any STA, the LTF in the PPDU transmitted by the STA is obtained based on the value of the LTF sequence and the matrix P. It should be understood that the value of the LTF sequence is specified in the protocol. The matrix P is an orthogonal mapping matrix. When the number of dimensions is determined, the value of the matrix P is specified in the protocol. For example, the matrix P with dimensions of 4×4 is

[0244]

number

[0245] It is.

[0246] In a possible implementation, the dimensionality of matrix P is determined based on the number of STAs triggered by the trigger frame, the maximum number of STAs supported by the system, and the maximum number of spatial streams supported by a single STA in at least one STA.

[0247] The number of STAs triggered by the trigger frame is at least one STA and is equal to or smaller than the number N of STAs that actually perform transmission. u It should be understood that the maximum number of STAs supported by the system can also be understood as the maximum number of STAs supported by the EHT (or other protocols that may appear in the future) in a distributed RU scenario, or the number of STAs supported by the first transmission bandwidth.

[0248] It should be further understood that the values ​​of the LTF sequence are specified in the protocol. The matrix P is an orthogonal mapping matrix. When the number of dimensions is determined, the values ​​of the matrix P are specified by the protocol. For example, a matrix P with dimensions of 4×4 is

[0249]

number

[0250] It is.

[0251] The dimension of matrix P is N LTF ×N LTF N LTF is the number of OFDM symbols contained in the LTF, (N u ×N ms )≦N LTF ≦(N mu ×N ms ), and N u Please refer to the explanation above for the meaning of N mu is the maximum number of STAs supported by the system, and N ms is the maximum number of spatial streams supported by a single STA in at least one STA.

[0252] In a possible implementation, for any STA in the at least one STA, the STA may determine a corresponding row from matrix P based on the order of the STA in the at least one STA, and then obtain an LTF based on the corresponding row determined from matrix P and the value of the LTF sequence.

[0253] For example, the i-th STA in at least one STA is the (i-1)×N ms +1 to i×N ms The order of the STAs in the at least one STA may also be understood as the sequence number of the STAs, i.e., the sequence number of the STAs in the at least one STA, where 1≦i≦N u It should be understood that.

[0254] For example, the maximum number of spatial streams supported by a single STA in at least one STA, N msAssume that P is 2, STA#1 (i.e., the STA with sequence number 1) in at least one STA corresponds to the first and second rows in matrix P, STA#2 (i.e., the STA with sequence number 2) in at least one STA corresponds to the third and fourth rows in matrix P, and STA#3 (i.e., the STA with sequence number 3) in at least one STA corresponds to the fifth and sixth rows in matrix P. The rest can be inferred by analogy.

[0255] In this application, all subcarriers include data subcarriers and pilot subcarriers.

[0256] In a possible implementation, the LTF (X k ) satisfies equation (1), and the k-th subcarrier is a data subcarrier.

[0257]

number

[0258] The LTF (X d ) satisfies equation (2), and the d-th subcarrier is a pilot subcarrier.

[0259]

number

[0260] The details are as follows: i is the (i-1)×N ms +1 to i×N ms The first S in the th row i row, S i is the number of spatial streams actually transmitted by the STA with sequence number i, and 1≦S i ≦N ms It is. ican be understood as a matrix P of STAs with sequence number i. As explained above, the (i-1) × N ms +1 to i×N ms The th row corresponds to the sequence number i of the STA and is a row in the matrix P, or the (i-1)×N ms +1 to i×N ms The Nth row corresponds to the STA with sequence number i and is in the matrix P. For example, u = 4, and N ms = 2, and at least one STA #1 (i.e., the STA with sequence number 1) and STA #2 (i.e., the STA with sequence number 2 Assume that the number of spatial streams actually transmitted by STA#3 (i.e., the STA with sequence number 3) and STA#4 (i.e., the STA with sequence number 4) in at least one STA is 1. In this case, the matrix P of the STA with sequence number 1 is

[0261]

number

[0262] and the matrix P of the STA with sequence number 2 is

[0263]

number

[0264] and the matrix P of the STA with sequence number 3 is P3 = [5th row in P], and the matrix P of the STA with sequence number 4 is P4 = [7th row in P], where P in matrix refers to matrix P.

[0265] Matrices P and N LTF For the meaning and values, see the explanation above.

[0266] LTFk is the value of the LTF sequence corresponding to the kth subcarrier.

[0267] LTF d is the value of the LTF sequence corresponding to the d-th subcarrier.

[0268] F is the first row of the matrix P.

[0269] For example, it should be noted that the first transmission bandwidth is 20 MHz, and the number of subcarriers in the first transmission bandwidth is 256. In this case, all subcarriers in the first transmission bandwidth are from the 1st subcarrier to the 256th subcarrier in ascending order of frequency, where 1≦k≦256 and 1≦d≦256. The 256 subcarriers include pilot subcarriers and data subcarriers, and may further include one or more of guard subcarriers, DC subcarriers, and null subcarriers.

[0270] In the prior art, the matrix multiplied by the LTF sequence is matrix P, where matrix P is determined by the STA based on the number of spatial streams actually transmitted by the STA. For example, assuming that the number of spatial streams actually transmitted by the STA is 2, the matrix P corresponding to the STA is a 2×2 orthogonal mapping matrix specified by the protocol.

[0271] However, in this embodiment of the present application, the matrix P i is a matrix P shared among at least one STA based on the number of spatial streams actually transmitted by the STA (i.e., the above N LTF ×N LTF The LTF is determined by the STA from the orthogonal mapping matrix of the LTF. In this way, it is possible to prevent inter-user interference caused by the transmission of the LTF by each STA.

[0272] Optionally, i satisfies equation (3).

[0273]

number

[0274] T F is the duration between the reception of a trigger frame by a STA and the reception of a user information field corresponding to the STA, and T L is the duration from the reception of a trigger frame by the STA to the reception of the first user information field in the trigger frame, and T C is the length of the user information field corresponding to the STA.

[0275] It should be noted that in this embodiment of this application, in the common field of the trigger frame (as shown in FIG. 11(b)), if B55=0, it indicates that the first user information field in the user information list is an extension of the common field and is called a special user information field. In this case, i=i'-1 needs to be set. In other words, when B55=0, the special user information field is used as an extension of the common field, and one less user information field is actually assigned to the user. Therefore, the actual user sequence number (STA's sequence number i) is the sequence number i' of the user information field minus one, that is, i=i'-1. When B55=1, the user sequence number (STA's sequence number i) is equal to the sequence number i' of the user information field.

[0276] T F And, T L And, T C For the relationship between, see FIG. 11 or FIG. 11(a).

[0277] It should be noted that i may alternatively be determined in other manners, for example, the sequence number of each STA may be carried in the trigger frame, for example, the sequence number of the corresponding STA is carried in each user information field in the trigger frame.

[0278] Optionally, the method may further include the following steps:

[0279] S1030: The AP determines channel coefficients of data subcarriers in the first transmission bandwidth based on LTFs received on the data subcarriers in the first transmission bandwidth.

[0280] In this embodiment, the LTF of the at least one STA is carried on all subcarriers in the first transmission bandwidth, and the AP may determine a channel coefficient of any data subcarrier in the first transmission bandwidth based on the LTF received on the data subcarrier, where the channel coefficient includes a channel coefficient of each STA in the at least one STA on the data subcarrier.

[0281] In a possible implementation, the channel coefficient H of the kth subcarrier in all subcarriers in the first transmission bandwidth is k satisfies equation (4).

[0282]

number

[0283] The kth subcarrier is a data subcarrier.

[0284] Y k is the LTF received by the AP on the kth subcarrier.

[0285] N LTF and LTF k For the meaning and values, see the explanation above.

[0286] P r * , P r is the conjugate transpose of

[0287]

number

[0288] or

[0289]

number

[0290] It is.

[0291] P i For the meaning and value of i, please refer to the above description. i is the sequence number of an STA. In other words, i is the sequence number of an STA in at least one STA, and i ∈ [1, N u ].

[0292] Furthermore, the method may further include the following steps.

[0293] S1040: The AP calculates the channel coefficient H k Determine a channel coefficient of the STA with sequence number i for each data subcarrier in all subcarriers in the first transmission bandwidth based on:

[0294] S1050: The AP demodulates data transmitted by the STA with sequence number i based on a channel coefficient of the STA with sequence number i for each data subcarrier in all subcarriers in the first transmission bandwidth.

[0295] The channel coefficient of the STA with sequence number i for the kth subcarrier is H k Q in 1_i th to Q 2_i th column, P i , P r Q in 1_i th to Q 2_i In other words, the channel coefficient of the STA with sequence number i for the kth subcarrier is P i P occupied byr For example, the P1 occupied by P1 corresponding to STA#1 (i.e., the STA with sequence number 1) can be obtained based on the row in r If the rows in are the first and second rows, the channel coefficient of STA#1 on the k-th subcarrier is H k The first and second columns in

[0296] In this embodiment, the AP may obtain the channel coefficient of at least one STA for each data subcarrier in the first transmission bandwidth according to Equation (4), and then extract the channel coefficient of each STA on each data subcarrier in the first transmission bandwidth from the channel coefficient. Thus, for any STA, the AP may demodulate the data transmitted by the STA based on the channel coefficient of the STA on each data subcarrier in the first transmission bandwidth to obtain the data transmitted by the STA.

[0297] 13 is a schematic flow chart of a method 2000 for transmitting a PPDU according to an embodiment of this application. The steps shown in FIG. 13 are described below.

[0298] S2010: The AP transmits a trigger frame.

[0299] This step is the same as S1010. Please refer to S1010.

[0300] It should be understood that if the resource allocation information in the trigger frame is resource allocation information of a distributed RU, the STA may also determine contiguous RUs corresponding to at least one distributed RU allocated by the AP based on the correspondence relationship between the distributed RUs and the contiguous RUs.

[0301] S2020: At least one STA individually transmits a respective PPDU to the AP based on the trigger frame. In response, the AP receives at least one PPDU transmitted by the at least one STA, and one STA transmits one PPDU.

[0302] The PPDU includes a data field and an LTF.

[0303] The manner of carrying the data field is the same as that of method 1000. In other words, the data field (or the data information in the data field) is carried on distributed RUs.

[0304] The manner of carrying the LTF differs from that of method 1000. In this method, the LTF is carried on all subcarriers of a number of consecutive RUs, which are consecutive RUs corresponding to distributed RUs carrying data.

[0305] For example, assume that a distributed RU includes subcarriers 1-17 and subcarriers 20-30. Subcarriers 1-17 may be mapped to subcarriers in consecutive RU #1, and subcarriers 20-30 may be mapped to subcarriers in consecutive RU #2. In this case, the distributed RU corresponds to RU #1 and RU #2. If the subcarriers included in consecutive RU #1 are subcarriers 1-26 and the subcarriers included in consecutive RU #2 are subcarriers 28-53, then the LTF may be carried on subcarriers 1-26 and subcarriers 28-53.

[0306] For the format of the PPDU transmitted by the STA, please refer to the description of the method 1000. The details will not be described again here.

[0307] According to the method for transmitting PPDU provided in this application, in a scenario where data is carried on distributed RUs, the LTF is carried on all subcarriers in consecutive RUs corresponding to the distributed RUs. Thus, the PAPR of the LTF can be guaranteed, thereby ensuring system performance. In addition, compared with the scheme in which the LTF is carried on all subcarriers in the first transmission bandwidth, the scheme in which the LTF is carried only on all subcarriers of consecutive RUs corresponding to the distributed RUs can reduce interference and reduce redundant subcarriers for transmission.

[0308] Optionally, for how to obtain the LTF in the PPDU transmitted by each STA, how to determine the LTF carried on the data subcarriers, and how to determine the LTF on the pilot subcarriers, please refer to the above description of method 1000. Details will not be described again here. However, it should be emphasized that the LTF described in method 1000 is carried on the first transmission bandwidth, and the LTF in method 2000 is carried on the contiguous RUs corresponding to the distributed RUs carrying data.

[0309] In addition, the values ​​of k and d in method 2000 will now be described with the aid of an example. For example, the consecutive RUs are two 26-tone RUs. Since each consecutive RU has 26 subcarriers, the consecutive RUs have 52 subcarriers. In this case, all subcarriers of the consecutive RUs are from the 1st subcarrier to the 52nd subcarrier in ascending frequency order, where 1≦k≦52 and 1≦d≦52.

[0310] Optionally, the method may further include the following steps:

[0311] S2030: The AP determines a channel coefficient of each data subcarrier of all data subcarriers of the t-th consecutive RU based on the LTF received on all data subcarriers in the t-th consecutive RU within the second transmission bandwidth.

[0312] The second transmission bandwidth is a bandwidth corresponding to a plurality of consecutive RUs assigned by the AP to the at least one STA for transmitting a respective LTF. In particular, each STA in the at least one STA transmits an LTF on all subcarriers in the plurality of consecutive RUs. In other words, each STA corresponds to a plurality of consecutive RUs, and the sum of the bandwidths of the consecutive RUs in the set of consecutive RUs corresponding to the at least one STA is the second transmission bandwidth. The set of consecutive RUs corresponding to the at least one STA includes the consecutive RUs corresponding to each STA in the at least one STA, and any two consecutive RUs in the set are different.

[0313] For example, the at least one PPDU is PPDU#1 and PPDU#2. The LTF in PPDU#1 is carried on distributed RU#1. Distributed RU#1 corresponds to consecutive RU#1 and consecutive RU#2. The LTF in PPDU#2 is carried on distributed RU#2. Distributed RU#2 corresponds to consecutive RU#3 and consecutive RU#4. In this case, the second transmission bandwidth is the sum of the bandwidths of consecutive RU#1, consecutive RU#2, consecutive RU#3, and consecutive RU#4, where 1≦t≦4.

[0314] In another example, the at least one PPDU is PPDU#1 and PPDU#2. The LTF in PPDU#1 is carried on distributed RU#1. Distributed RU#1 corresponds to consecutive RU#1 and consecutive RU#2. The LTF in PPDU#2 is carried on distributed RU#2. Distributed RU#2 corresponds to consecutive RU#2 and consecutive RU#3. In this case, the second transmission bandwidth is the sum of the bandwidths of consecutive RU#1, consecutive RU#2, and consecutive RU#3, where 1≦t≦3.

[0315] It should be understood that in this embodiment, a data subcarrier in the t-th consecutive RU may carry only the LTF of one STA in the at least one STA, or may carry the LTF of multiple STAs in the at least one STA. If a data subcarrier in the t-th consecutive RU carries only the LTF of one STA in the at least one STA, the channel coefficients of the data subcarriers in the t-th consecutive RU and determined by the AP are the channel coefficients of the STA on the data subcarriers in the t-th consecutive RU. If a data subcarrier in the t-th consecutive RU carries the LTFs of multiple STAs in the at least one STA, the channel coefficients of the data subcarriers in the t-th consecutive RU and determined by the AP include the channel coefficients of multiple STAs on the data subcarriers in the t-th consecutive RU.

[0316] In a possible implementation, the channel coefficient H of the k'th subcarrier in all subcarriers of the tth consecutive RU k’ (t) satisfies equation (5).

[0317]

number

[0318] The k'th subcarrier is a data subcarrier.

[0319] Y k’ is the LTF received by the AP on the k'th subcarrier.

[0320] N LTF is the number of OFDM symbols contained in the LTF, (N u ×N ms )≦N LTF ≦(N mu ×N ms ), and N u is the number of STAs triggered by the trigger frame, and N mu is the maximum number of STAs supported by the system, and Nms is the maximum number of spatial streams that can be transmitted by a single STA.

[0321] (P r (t) ) * , P r (t) is the conjugate transpose of

[0322]

number

[0323] or

[0324]

number

[0325] It is.

[0326] u is the number of STAs whose corresponding LTFs are carried on the tth consecutive RU.

[0327]

number

[0328] is the (i t -1) × N ms +1st to i t ×N ms The first in the th row

[0329]

number

[0330] row, and (i t -1) × N ms +1st to i t ×N ms The th row is the sequence number of the STA i in the matrix P. t is the row corresponding to it ∈[1,N u ], and i t is the sequence number of the STA that transmits the LTF using the tth consecutive RU,

[0331]

number

[0332] is sequence number i t is the number of spatial streams actually transmitted by the STA with

[0333]

number

[0334] and the matrix P is N LTF ×N LTF is the orthogonal mapping matrix of LTF k’ (t) is the value of the LTF sequence corresponding to the k'th subcarrier of the tth RU.

[0335] It should be understood that the number of STAs whose corresponding LTFs are carried on different consecutive RUs may vary. In other words, the value of u may vary when t has different values. For example, if the tth consecutive RU carries the LTFs of three STAs, then u=3. If the tth consecutive RU carries the LTFs of one STA, then u=1.

[0336] i t It should be further understood that i is a sequence number of a STA in at least one STA, and the STA transmits an LTF using the t-th consecutive RU. tis not the sequence number of the STA that transmits the LTF using the t-th consecutive RU among the u STAs. The sequence number of any STA among the at least one STA may be determined according to the above formula (3), or may be determined in other manners. For example, the sequence number of each STA may be carried in a trigger frame. In this embodiment, the AP may obtain a channel coefficient of each data subcarrier in each consecutive RU according to formula (5), where the channel coefficient of any data subcarrier includes the channel coefficient of one or more STAs whose corresponding LTF is carried on the data subcarrier. Alternatively, for any STA, the AP may obtain a channel coefficient of each data subcarrier in each RU of the multiple consecutive RUs corresponding to the distributed RUs carrying the data of the STA according to formula (5).

[0337] Furthermore, the method may further include the following steps.

[0338] S2040: The AP calculates the channel coefficient H k’ Based on the above, for each data subcarrier of each consecutive RU in the plurality of consecutive RUs corresponding to the STA, the sequence number i t The channel coefficients of the STAs having the

[0339] S2050: The AP determines a sequence number i for each data subcarrier of each consecutive RU in the plurality of consecutive RUs corresponding to the STA. t Based on the channel coefficient of the STA with sequence number i t The STA demodulates data transmitted by the STA having

[0340] Sequence number i t The LTF of a STA with sequence number i is carried on the t-th consecutive RU, and the LTF of a STA with sequence number i is carried on the k'-th subcarrier in the t-th consecutive RU. t The channel coefficient of the STA with k’ (t) Within

[0341]

number

[0342] From

[0343]

number

[0344] is the th column,

[0345]

number

[0346] , P r (t) Within

[0347]

number

[0348] From

[0349]

number

[0350] In other words, for the kth subcarrier, the sequence number t i The channel coefficient of the STA with sequence number i t Corresponding to STA with

[0351]

number

[0352] P occupied by r (t) This can be understood based on the lines inside.

[0353] In this embodiment, the AP knows which consecutive RUs carry the LTFs transmitted by each STA. Therefore, for any STA, the AP may know the channel coefficient of the STA for the data subcarriers in each RU of the multiple consecutive RUs corresponding to the STA according to Equation (5). In this way, it is equivalent to the AP knowing the channel coefficient of the STA, and the AP may demodulate the data transmitted by the STA based on the channel coefficient of the STA to obtain the data transmitted by the STA.

[0354] Hereinafter, a method for transmitting a PPDU is further provided. The method is further described with reference to the steps shown in Figures 10 and 11, 11(a), 11(b), 11(c), and 12. It should be understood that the method for transmitting a PPDU provided in this embodiment has the same or similar content as the method for transmitting a PPDU provided in the previous embodiment described with reference to Figures 10, 11, 11(a), 11(b), 11(c), and 12. If there is no contradiction, the relevant content in the previous embodiment may be cited or carried over in this embodiment. For the sake of brevity, the details will not be described again here.

[0355] S1010: The AP transmits a trigger frame.

[0356] The trigger frame is used to trigger at least one STA, which is denoted as STA#1 to STA#N in the figure, to transmit an uplink PPDU. u In other words, the trigger frame is to trigger N u Trigger one STA.

[0357] S1020: At least one STA individually transmits a respective PPDU to the AP based on the trigger frame. In response, the AP receives at least one PPDU transmitted by the at least one STA, and one STA transmits one PPDU.

[0358] Optionally, before S1020, the method may further include: At least one STA individually obtains an LTF to be transmitted by the at least one STA according to a value of the LTF sequence (or the LTF sequence) and the matrix P.

[0359] In a possible implementation, the dimension of the matrix P is N LTF ×N LTF In other words, the matrix P is LTF Row x N LTF It is a column matrix.

[0360] N LTF is the number of OFDM symbols contained in the LTF, i.e., the number of OFDM symbols for transmitting the LTF. LTF is determined based on the total number of streams carried by each STA in the first transmission bandwidth.

[0361] In a possible implementation, any STA in the at least one STA may determine a corresponding row from the matrix P based on an indication of an SS assignment field in a user information field in a trigger frame received by the STA. In particular, the SS assignment field includes two subfields. One is a starting spatial stream subfield indicating an assigned starting spatial stream index, and the other is a spatial stream number subfield indicating the number of assigned spatial streams. The STA selects rows from (starting spatial stream index+1)th to (starting spatial stream index+number of assigned streams)th in the matrix P. Then, the LTF is obtained based on the corresponding row determined from the matrix P and the value of the LTF sequence.

[0362] In this application, all subcarriers within the transmission bandwidth include data subcarriers and pilot subcarriers.

[0363] In a possible implementation, the LTF (X k ) satisfies equation (1), and the k-th subcarrier is a data subcarrier.

[0364]

number

[0365] The LTF (X d ) satisfies equation (2), and the d-th subcarrier is a pilot subcarrier.

[0366]

number

[0367] P i is the I in matrix P i +1st to I i +NUM i th row, I i is the starting spatial stream sequence number of the i-th user, which is obtained by sorting all streams of all users on the first transmission bandwidth, and NUM i is the number of streams of the i-th user, and I i and NUM i is indicated by the SS assignment field in the user information field of STA i. For example, the first four bits in the SS assignment are the starting spatial stream subfield, as shown in FIG. 11(c). If the value of the first four bits is 3, it indicates the starting spatial stream sequence number I iThe last two bits are the Number of Spatial Stream subfield. If the value of the last two bits is 2, it indicates the number of spatial streams, NUM i is 2. In other words, the fourth and fifth streams are allocated.

[0368] P i may be understood as the matrix P of STA i.

[0369] For the meaning and values ​​of the matrix P, see the above explanation.

[0370] N LTF is the number of OFDM symbols contained in the LTF, the value of which is not smaller than the total number of streams of all users on the first transmission bandwidth.

[0371] LTF k is the value of the LTF sequence corresponding to the kth subcarrier.

[0372] LTF d is the value of the LTF sequence corresponding to the d-th subcarrier.

[0373] F is the first row in the matrix P. For example, it should be noted that the first transmission bandwidth is 20 MHz, and the number of subcarriers in the first transmission bandwidth is 256. In this case, all subcarriers in the first transmission bandwidth are from the 1st subcarrier to the 256th subcarrier in ascending order of frequency, where 1≦k≦256 and 1≦d≦256. The 256 subcarriers include pilot subcarriers and data subcarriers, and may further include one or more of guard subcarriers, DC subcarriers, and null subcarriers. It should be understood that when the first transmission bandwidth is a bandwidth such as 40 MHz, 80 MHz, 160 MHz, 240 MHz, or 320 MHz, all subcarriers included in the first transmission bandwidth are utilized in the same manner. Details will not be described again here.

[0374] In the prior art, the matrix multiplied by the LTF sequence is matrix P, and matrix P in the prior art is determined by the STA according to the number of spatial streams actually transmitted by the STA. For example, assuming that the number of spatial streams actually transmitted by the STA is 2, the matrix P corresponding to the STA is a 2×2 orthogonal mapping matrix specified by the protocol.

[0375] However, in this embodiment of the present application, the matrix P i is a matrix P shared among at least one STA based on the number of spatial streams actually transmitted by the STA (i.e., the above N LTF ×N LTF The matrix P is determined by the STA from the orthogonal mapping matrix P. In the matrix P, the interference between STAs is fully taken into account. In this way, the inter-user interference caused by each STA transmitting the LTF can be prevented.

[0376] Optionally, the method may further include the following steps:

[0377] S1030: The AP determines channel coefficients of data subcarriers in the first transmission bandwidth based on LTFs received on the data subcarriers in the first transmission bandwidth.

[0378] In this embodiment, the LTF of the at least one STA is carried on all subcarriers in the first transmission bandwidth, and the AP may determine a channel coefficient of any data subcarrier in the first transmission bandwidth based on the LTF received on the data subcarrier, where the channel coefficient includes a channel coefficient of each STA in the at least one STA on the data subcarrier.

[0379] In a possible implementation, the channel coefficient of the kth subcarrier among all subcarriers in the first transmission bandwidth satisfies equation (4).

[0380]

number

[0381] The kth subcarrier is a data subcarrier.

[0382] Y k is the LTF received by the AP on the kth subcarrier.

[0383] N LTF and LTF k For the meaning and values, see the explanation above.

[0384] P r * , P r is the conjugate transpose of

[0385]

number

[0386] or

[0387]

number

[0388] It is.

[0389] P i For the meaning and values ​​of N, see the explanation above. u is the number of at least one STA that is triggered by the trigger frame. i is the sequence number of the STA. In other words, i is the number of STAs that are triggered by the trigger frame. u is the sequence number of one STA in the STAs, i ∈ [1,N u ].

[0390] Furthermore, the method may further include the following steps.

[0391] S1040: The AP calculates the channel coefficient H k Determine a channel coefficient of the STA with sequence number i for each data subcarrier in all subcarriers in the first transmission bandwidth based on:

[0392] S1050: The AP demodulates data transmitted by the STA with sequence number i based on a channel coefficient of the STA with sequence number i for each data subcarrier in all subcarriers in the first transmission bandwidth.

[0393] The channel coefficient of the STA with sequence number i for the kth subcarrier is H k I in i +1st to I i +NUM i This is the th column.

[0394] In this embodiment, the AP may obtain the channel coefficient of at least one STA for each data subcarrier in the first transmission bandwidth according to Equation (4), and then extract the channel coefficient of each STA on each data subcarrier in the first transmission bandwidth from the channel coefficient. Thus, for any STA, the AP may demodulate the data transmitted by the STA based on the channel coefficient of the STA on each data subcarrier in the first transmission bandwidth to obtain the data transmitted by the STA.

[0395] Correspondingly, an embodiment of this application further provides a method for transmitting a PPDU. An explanation is also provided with reference to FIG.

[0396] S2010: The AP transmits a trigger frame.

[0397] This step is the same as S1010. Please refer to S1010.

[0398] It should be understood that if the resource allocation information in the trigger frame is resource allocation information of a distributed RU, the STA may also determine contiguous RUs corresponding to at least one distributed RU allocated by the AP based on the correspondence relationship between the distributed RUs and the contiguous RUs.

[0399] S2020: At least one STA individually transmits a respective PPDU to the AP based on the trigger frame. In response, the AP receives at least one PPDU transmitted by the at least one STA, and one STA transmits one PPDU.

[0400] The PPDU includes a data field and an LTF.

[0401] In one implementation, the manner of carrying the data field is the same as that of method 1000. In other words, the data field (or the data information in the data field) is carried on distributed RUs.

[0402] In other implementations, the manner of carrying the LTF is different from that of method 1000. In this method, the LTF is carried on all subcarriers of a number of consecutive RUs, the number of consecutive RUs being consecutive RUs corresponding to the distributed RUs carrying data.

[0403] For example, assume that a distributed RU includes subcarriers 1-17 and subcarriers 20-30. Subcarriers 1-17 may be mapped to subcarriers in consecutive RU #1, and subcarriers 20-30 may be mapped to subcarriers in consecutive RU #2. In this case, the distributed RU corresponds to RU #1 and RU #2. If the subcarriers included in consecutive RU #1 are subcarriers 1-26 and the subcarriers included in consecutive RU #2 are subcarriers 28-53, then the LTF may be carried on subcarriers 1-26 and subcarriers 28-53.

[0404] For the format of the PPDU transmitted by the STA, please refer to the description of the method 1000. The details will not be described again here.

[0405] According to the method for transmitting PPDU provided in this application, in a scenario where data is carried on distributed RUs, the LTF is carried on all subcarriers in consecutive RUs corresponding to the distributed RUs. Thus, the PAPR of the LTF can be guaranteed, thereby ensuring system performance. In addition, compared with the scheme in which the LTF is carried on all subcarriers in the first transmission bandwidth, the scheme in which the LTF is carried only on all subcarriers of consecutive RUs corresponding to the distributed RUs can reduce interference and reduce redundant subcarriers for transmission.

[0406] Optionally, for how to obtain the LTF in the PPDU transmitted by each STA, how to determine the LTF carried on the data subcarriers, and how to determine the LTF on the pilot subcarriers, please refer to the above description of method 1000. Details will not be described again here. However, it should be emphasized that the LTF described in method 1000 is carried on the first transmission bandwidth, and the LTF in method 2000 is carried on the contiguous RUs corresponding to the distributed RUs carrying data.

[0407] In addition, the values ​​of k and d in method 2000 will now be described with the aid of an example. For example, the consecutive RUs are two 26-tone RUs. Since each consecutive RU has 26 subcarriers, the consecutive RUs have 52 subcarriers. In this case, all subcarriers of the consecutive RUs are from the 1st subcarrier to the 52nd subcarrier in ascending frequency order, where 1≦k≦52 and 1≦d≦52.

[0408] Optionally, the method may further include the following steps:

[0409] S2030: The AP determines a channel coefficient of each data subcarrier of all data subcarriers of the t-th consecutive RU based on the LTF received on all data subcarriers in the t-th consecutive RU within the second transmission bandwidth.

[0410] The second transmission bandwidth is a bandwidth corresponding to a plurality of consecutive RUs assigned by the AP to the at least one STA for transmitting a respective LTF. In particular, each STA in the at least one STA transmits an LTF on all subcarriers in the plurality of consecutive RUs. In other words, each STA corresponds to a plurality of consecutive RUs, and the sum of the bandwidths of the consecutive RUs in the set of consecutive RUs corresponding to the at least one STA is the second transmission bandwidth. The set of consecutive RUs corresponding to the at least one STA includes the consecutive RUs corresponding to each STA in the at least one STA, and any two consecutive RUs in the set are different.

[0411] For example, the at least one PPDU is PPDU#1 and PPDU#2. The LTF in PPDU#1 is carried on distributed RU#1. Distributed RU#1 corresponds to consecutive RU#1 and consecutive RU#2. The LTF in PPDU#2 is carried on distributed RU#2. Distributed RU#2 corresponds to consecutive RU#3 and consecutive RU#4. In this case, the second transmission bandwidth is the sum of the bandwidths of consecutive RU#1, consecutive RU#2, consecutive RU#3, and consecutive RU#4, where 1≦t≦4.

[0412] In another example, the at least one PPDU is PPDU#1 and PPDU#2. The LTF in PPDU#1 is carried on distributed RU#1. Distributed RU#1 corresponds to continuous RU#1 and continuous RU#2. The LTF in PPDU#2 is carried on distributed RU#2, which corresponds to consecutive RU#2 and consecutive RU#3, where the second transmission bandwidth is the sum of the bandwidths of consecutive RU#1, consecutive RU#2, and consecutive RU#3, where 1≦t≦3.

[0413] It should be understood that in this embodiment, a data subcarrier in the t-th consecutive RU may carry only the LTF of one STA in the at least one STA, or may carry the LTF of multiple STAs in the at least one STA. If a data subcarrier in the t-th consecutive RU carries only the LTF of one STA in the at least one STA, the channel coefficients of the data subcarriers in the t-th consecutive RU and determined by the AP are the channel coefficients of the STA on the data subcarriers in the t-th consecutive RU. If a data subcarrier in the t-th consecutive RU carries the LTFs of multiple STAs in the at least one STA, the channel coefficients of the data subcarriers in the t-th consecutive RU and determined by the AP include the channel coefficients of multiple STAs on the data subcarriers in the t-th consecutive RU.

[0414] In a possible implementation, the channel coefficient H of the k'th subcarrier in all subcarriers of the tth consecutive RU k’ (t) satisfies equation (5).

[0415]

number

[0416] The k'th subcarrier is a data subcarrier.

[0417] Y k’ is the LTF received by the AP on the k'th subcarrier.

[0418] N LTF is the number of OFDM symbols contained in the LTF. LTF For the meaning and values, see the explanation above.

[0419] (P r (t) ) * , P r (t) is the conjugate transpose of

[0420]

number

[0421] or

[0422]

number

[0423] u is the number of STAs whose corresponding LTFs are carried on the t-th consecutive RU.

[0424]

number

[0425] is the

[0426]

number

[0427] From

[0428]

number

[0429] is the th row,

[0430]

number

[0431] i t is the starting spatial stream sequence number of the th user,

[0432]

number

[0433] i t is the number of streams for the th user,

[0434]

number

[0435] and

[0436]

number

[0437] STA i t The SS assignment field in the user information field of t ∈[1,N u ], and i t is the sequence number of the STA that transmits the LTF using the tth consecutive RU, and N u is the number of at least one STA that is triggered by the trigger frame, and the matrix P is N LTF ×N LTF is the orthogonal mapping matrix of LTF k’ (t) is the value of the LTF sequence corresponding to the k'th subcarrier of the tth RU.

[0438] It should be understood that the number of STAs whose corresponding LTFs are carried on different consecutive RUs may vary. In other words, the value of u may vary when t has different values. For example, if the tth consecutive RU carries the LTFs of three STAs, then u=3. If the tth consecutive RU carries the LTFs of one STA, then u=1.

[0439] i t But, N u It should be further understood that, i is the sequence number of a STA in the STAs, and the STA transmits an LTF using the t-th consecutive RU. tis not the sequence number of a STA that transmits an LTF using the t-th consecutive RU on the t-th consecutive RU among the u STAs.

[0440] In this embodiment, the AP may obtain a channel coefficient for each data subcarrier in each consecutive RU according to equation (5), where the channel coefficient for any data subcarrier includes the channel coefficients of one or more STAs whose corresponding LTFs are carried on the data subcarrier. Alternatively, for any STA, the AP may obtain a channel coefficient for each data subcarrier in each RU of multiple consecutive RUs corresponding to distributed RUs carrying data for the STA according to equation (5).

[0441] Furthermore, the method may further include the following steps.

[0442] S2040: The AP calculates the channel coefficient H k’ Based on the above, for each data subcarrier of each consecutive RU in the plurality of consecutive RUs corresponding to the STA, the sequence number i t The channel coefficients of the STAs having the

[0443] S2050: The AP determines a sequence number i for each data subcarrier of each consecutive RU in the plurality of consecutive RUs corresponding to the STA. t Based on the channel coefficient of the STA with sequence number i t The STA demodulates data transmitted by the STA having

[0444] Sequence number i t The LTF of a STA with sequence number i is carried on the t-th consecutive RU, and the LTF of a STA with sequence number i is carried on the k'-th subcarrier in the t-th consecutive RU. t The channel coefficient of the STA with k’ (t) Within

[0445]

number

[0446] From

[0447]

number

[0448] is the th column,

[0449]

number

[0450] , P r (t) Within

[0451]

number

[0452] From

[0453]

number

[0454] In other words, for the k'th subcarrier, the sequence number t i The channel coefficient of the STA with sequence number i t Corresponding to STA with

[0455]

number

[0456] P occupied by r (t) This can be understood based on the lines inside.

[0457] In this embodiment, the AP knows which consecutive RUs carry the LTFs transmitted by each STA. Therefore, for any STA, the AP may know the channel coefficient of the STA for the data subcarriers in each RU of the multiple consecutive RUs corresponding to the STA according to Equation (5). In this way, it is equivalent to the AP knowing the channel coefficient of the STA, and the AP may demodulate the data transmitted by the STA based on the channel coefficient of the STA to obtain the data transmitted by the STA.

[0458] This application further provides a communication device. Please refer to FIG. 14. FIG. 14 is a schematic block diagram of a communication device according to an embodiment of this application. As shown in FIG. 14, the communication device 3000 may include a transceiver unit 3100. Optionally, the device 3000 may further include a processing unit 3200.

[0459] The transceiver unit 3100 may be configured to transmit information to or receive information from other devices, e.g., transmit or receive trigger frames or PPDUs. The processing unit 3200 may be configured to perform internal processing of the device, e.g., determine channel coefficients.

[0460] In some implementations, the communication device 3000 may correspond to a STA in the method 1000, for example, specifically, may be a STA or a chip configured in a STA. In addition, the units in the communication device 3000 are respectively utilized in the operations performed by the STA in the method 1000.

[0461] In particular, the transceiver unit 3100 is configured to receive a trigger frame from an AP, the trigger frame being used to trigger at least one STA to transmit an uplink physical layer protocol data unit PPDU, and transmit the PPDU to the AP based on the trigger frame. The PPDU includes a data field and a long training field LTF used for channel estimation. The data field is carried on a distributed resource unit RU. The distributed RU includes multiple subcarrier groups distributed in the frequency domain. One subcarrier group includes one subcarrier or includes at least two consecutive subcarriers. The LTF is carried on all subcarriers in a first transmission bandwidth. The first transmission bandwidth is a bandwidth corresponding to the distributed RU allocated by the AP to the at least one STA to transmit the uplink PPDU.

[0462] In another implementation, the communication device 3000 may correspond to the STA in the method 2000, for example, specifically, may be a STA or a chip configured in the STA. In addition, the units in the communication device 3000 are respectively utilized in the operations performed by the STA in the method 2000.

[0463] Specifically, the transceiver unit 3100 is configured to receive a trigger frame from an AP, the trigger frame being used to trigger at least one station STA to transmit an uplink physical layer protocol data unit PPDU, and transmit the physical layer protocol data unit PPDU to the AP based on the trigger frame. The PPDU includes a data field and a long training field LTF used for channel estimation. The data field is carried on a distributed resource unit RU. The distributed RU includes multiple subcarrier groups distributed in a frequency domain. One subcarrier group includes one subcarrier or at least two consecutive subcarriers. The LTF is carried on all subcarriers of the multiple consecutive RUs. The multiple consecutive RUs are consecutive RUs corresponding to the distributed RUs. Each consecutive RU includes multiple subcarriers that are consecutive in the frequency domain.

[0464] Optionally, the processing unit 3200 is configured to obtain the LTFs carried on all the subcarriers based on the values ​​of the LTF sequence and the matrix P.

[0465] In one implementation, the dimensionality of matrix P is determined based on the number of STAs triggered by the trigger frame, the maximum number of STAs supported by the system, and the maximum number of spatial streams supported by a single STA in at least one STA.

[0466] In other implementations, the dimension of the matrix P is N LTF ×N LTF In other words, the matrix P is LTF Row x N LTF is a column matrix. LTF is the number of OFDM symbols contained in the LTF, i.e., the number of OFDM symbols for transmitting the LTF. LTF is determined based on the total number of streams carried by each STA in the first transmission bandwidth.

[0467] Optionally, in one implementation, the processing unit 3200 is configured to determine a corresponding row from the matrix P based on an order of the STAs in the at least one STA, in particular, and the STA obtains the LTFs to be carried on all subcarriers based on the corresponding row determined from the matrix P and the value of the LTF sequence.

[0468] In another implementation, the processing unit 3200 determines a corresponding row from the matrix P based on an indication of the SS assignment field in the user information field in the trigger frame received by the STA.

[0469] Optionally, the LTF X carried on the k-th subcarrier among all the subcarriers k , and the LTF X carried on the d-th subcarrier among all the subcarriers. d X k =P i ×LTF k , and X d =F×LTF d Each of the following conditions is satisfied.

[0470] In one implementation, the kth subcarrier is a data subcarrier, the dth subcarrier is a pilot subcarrier, and P i is the (i-1)×N ms +1 to i×N ms The first S in the th row i row, (i-1)×N in matrix P ms +1 to i×N ms The th row is the row in matrix P corresponding to the sequence number i of the STA, and matrix P has N LTF ×N LTF is the orthogonal mapping matrix of N LTF is the number of orthogonal frequency division multiplexing OFDM symbols contained in the LTF, (N u ×N ms )≦N LTF ≦(N mu ×N ms ), and N uis the number of STAs triggered by the trigger frame, and N mu is the maximum number of STAs supported by the system, and N ms is the maximum number of spatial streams supported by a single STA, i is the sequence number of the STA, and 1≦i≦N u And S i is the number of spatial streams actually transmitted by the STA with sequence number i, and 1≦S i ≦N ms And LTF k is the value of the LTF sequence corresponding to the kth subcarrier, and LTF d is the value of the LTF sequence corresponding to the d-th subcarrier, and F is the first row of the matrix P.

[0471] Optionally, i is a function of i=(T F -T L ) / T c Meet +1.

[0472] T F is the duration between the reception of a trigger frame by a STA and the reception of a user information field corresponding to the STA, and T L is the duration from the reception of a trigger frame by the STA to the reception of the first user information field in the trigger frame, and T C is the length of the user information field corresponding to the STA.

[0473] Common fields of the trigger frame (Figure 11 (b)In the above (as shown in Figure 1), if B55=0, it indicates that the first user information field in the user information list is an extension of the common field and is called a special user information field. In this case, i=i'-1 should be set. In other words, when B55=0, the special user information field is used as an extension of the common field, and one less user information field is actually assigned to the user. Therefore, the actual user sequence number (STA's sequence number i) is the sequence number i' of the user information field minus one, i.e., i=i'-1. When B55=1, the user sequence number (STA's sequence number i) is equal to the sequence number i' of the user information field.

[0474] In another implementation, the kth subcarrier is a data subcarrier, the dth subcarrier is a pilot subcarrier, and P i is the I in matrix P i +1st to I i +NUM i th row, I i is the starting spatial stream sequence number of the i-th user, which is obtained by sorting all streams of all users on the first transmission bandwidth, and NUM i is the number of streams of the i-th user, and as shown in Fig. 11(c), I i and NUM i is indicated by the SS assignment field in the user information field of STA i. For example, the first four bits in the SS assignment are the Starting spatial stream subfield. If the value of the first four bits is 3, it indicates the starting spatial stream sequence number I i The last two bits are the Number of Spatial Stream subfield. If the value of the last two bits is 2, it indicates the number of spatial streams, NUM iis 2. In other words, the fourth and fifth streams are allocated.

[0475] P i may be understood as the matrix P of STA i.

[0476] For the meaning and values ​​of the matrix P, see the above explanation.

[0477] N LTF is the number of OFDM symbols contained in the LTF, and the value of this number is not smaller than the total number of streams of all users on the first transmission bandwidth. k is the value of the LTF sequence corresponding to the kth subcarrier. d is the value of the LTF sequence corresponding to the d-th subcarrier. F is the first row in the matrix P.

[0478] In some implementations, the communication device 3000 may correspond to the AP in the above method 1000, for example, specifically, may be an AP or a chip configured in an AP. In addition, the units in the communication device 3000 are each utilized to implement the operations performed by the AP in the method 1000.

[0479] Specifically, the transceiver unit 3100 is configured to transmit a trigger frame to at least one station STA, the trigger frame being used to trigger the at least one STA to transmit an uplink physical layer protocol data unit PPDU, and to receive each PPDU from the at least one STA. One of the PPDUs includes a data field and a long training field LTF used for channel estimation. The data field is carried on a distributed resource unit RU. The distributed RU includes multiple subcarrier groups distributed in the frequency domain. One subcarrier group includes one subcarrier or includes at least two consecutive subcarriers. The LTF is carried on all subcarriers in a first transmission bandwidth. The first transmission bandwidth is a bandwidth corresponding to the distributed RU assigned by the access point AP to the at least one STA to transmit the uplink PPDU.

[0480] Optionally, the processing unit 3200 is configured to determine channel coefficients of data subcarriers in the first transmission bandwidth based on the LTF received on the data subcarriers in the first transmission bandwidth.

[0481] Optionally, a channel coefficient H of the kth subcarrier in all subcarriers within the first transmission bandwidth k teeth,

[0482]

number

[0483] Meet the following.

[0484] The kth subcarrier is a data subcarrier, Y k is the LTF received by the AP on the kth subcarrier, and N LTF is the number of OFDM symbols contained in the LTF, (N u ×Nms )≦N LTF ≦(N mu ×N ms ), and N u is the number of STAs triggered by the trigger frame, and N mu is the maximum number of STAs supported by the system, and N ms is the maximum number of spatial streams supported by a single STA, and P r * , P r is the conjugate transpose of

[0485]

number

[0486] And P i is the (i-1)×N ms +1 to i×N ms The first S in the th row i row, (i-1)×N in matrix P ms +1 to i×N ms The th row is the row in matrix P that corresponds to the sequence number i of the STA, and 1≦S i ≦N ms where i∈[1,N u ], i is the sequence number of the STA, and S i is the number of spatial streams actually transmitted by the STA with sequence number i, and the matrix P is N LTF ×N LTF is the orthogonal mapping matrix of LTF k is the value of the LTF sequence corresponding to the kth subcarrier.

[0487] Optionally, the processing unit 3200 may further include a processing unit 3200 for processing the channel coefficient H kand the AP is further configured to determine a channel coefficient of the STA with sequence number i for each data subcarrier in all subcarriers in the first transmission bandwidth based on H, and the AP is further configured to demodulate the data transmitted by the STA with sequence number i based on the channel coefficient of the STA with sequence number i for each data subcarrier in all subcarriers in the first transmission bandwidth. In one implementation, the channel coefficient of the STA with sequence number i for the kth subcarrier is k Q in 1_i th to Q 2_i th column, P i , P r Q in 1_i th to Q 2_i In other implementations, the channel coefficient of the STA with sequence number i for the kth subcarrier is H k I in i +1st to I i +NUM i th column. In some implementations, the communication device 3000 may correspond to the AP in the above method 2000, for example, specifically, may be an AP or a chip configured within an AP. In addition, the units within the communication device 3000 are each utilized to implement the operations performed by the AP in the method 2000.

[0488] In particular, the transceiver unit 3100 is configured to transmit a trigger frame to at least one station STA, the trigger frame being used to trigger the at least one STA to transmit an uplink physical layer protocol data unit PPDU, and to receive each PPDU from the at least one STA. One of the PPDUs includes a data field and a long training field LTF used for channel estimation. The data field is carried on a distributed resource unit RU. The distributed RU includes a plurality of subcarrier groups distributed in a frequency domain. A subcarrier group includes one subcarrier or includes at least two consecutive subcarriers. The LTF is carried on all subcarriers of the plurality of consecutive RUs. The plurality of consecutive RUs are consecutive RUs corresponding to the distributed RUs. Each consecutive RU includes a plurality of subcarriers that are consecutive in a frequency domain.

[0489] Optionally, the processing unit 3200 is configured to determine a channel coefficient of each data subcarrier in all subcarriers of the t-th consecutive RU based on the LTF received on all data subcarriers in the t-th consecutive RU in a second transmission bandwidth, where the second transmission bandwidth is a bandwidth corresponding to a plurality of consecutive RUs assigned by the access point AP to at least one STA for transmitting each LTF.

[0490] Optionally, the channel coefficient H of the k'th subcarrier in all subcarriers of the tth consecutive RU k’ (t) teeth,

[0491]

number

[0492] Meet the following.

[0493] The k'th subcarrier is a data subcarrier, and Yk’ is the LTF received by the AP on the k'th subcarrier, and N LTF is the number of OFDM symbols contained in the LTF, (N u ×N ms )≦N LTF ≦(N mu ×N ms ), and N u is the number of STAs triggered by the trigger frame, and N mu is the maximum number of STAs supported by the system, and N ms is the maximum number of spatial streams supported by a single STA, (P r (t) ) * , P r (t) is the conjugate transpose of

[0494]

number

[0495] or

[0496]

number

[0497] where u is the number of STAs whose corresponding LTFs are carried on the t-th consecutive RU.

[0498]

number

[0499] is the (i t -1) × N ms +1st to i t ×N ms The first in the th row

[0500]

number

[0501] row, and (i t -1) × N ms +1st to i t ×N ms The th row is the sequence number of the STA i in the matrix P. t is the row corresponding to i t ∈[1,N u ], and i t is the sequence number of the STA that transmits the LTF using the tth consecutive RU,

[0502]

number

[0503] is sequence number i t is the number of spatial streams actually transmitted by the STA with

[0504]

number

[0505] and the matrix P is N LTF ×N LTF is the orthogonal mapping matrix of LTF k’ (t) is the value of the LTF sequence corresponding to the k'th subcarrier of the tth RU.

[0506]

number

[0507] is the

[0508]

number

[0509] From

[0510]

number

[0511] is the th row,

[0512]

number

[0513] i t is the starting spatial stream sequence number of the th user,

[0514]

number

[0515] i t is the number of streams for the th user,

[0516]

number

[0517] and

[0518]

number

[0519] STA i t The indication method is described in the above embodiment, and the details will not be described again here. t ∈[1,N u ], and i t is the sequence number of the STA that transmits the LTF using the t-th consecutive RU, and the matrix P is N LTF ×N LTF is the orthogonal mapping matrix of LTF k’(t) is the value of the LTF sequence corresponding to the k'th subcarrier of the tth RU.

[0520] Optionally, the processing unit 3200 may further include a processing unit 3200 for processing the channel coefficient H k’ Based on sequence number i t For each data subcarrier of each consecutive RU in the plurality of consecutive RUs corresponding to the STA having sequence number i t Determine the channel coefficients of the STA with sequence number i t For each data subcarrier of each consecutive RU in the plurality of consecutive RUs corresponding to the STA having sequence number i t Based on the channel coefficient of the STA with sequence number i t and further configured to demodulate data transmitted by the STA having sequence number i t The LTF of a STA with sequence number i is carried on the t-th consecutive RU, and the LTF of a STA with sequence number i is carried on the k'-th subcarrier in the t-th consecutive RU. t The channel coefficient of the STA with k’ (t) Within

[0521]

number

[0522] From

[0523]

number

[0524] is the th column,

[0525]

number

[0526] , P r (t) Within

[0527]

number

[0528] From

[0529]

number

[0530] This is the th line.

[0531] It should be understood that the specific process of the unit performing the above corresponding steps has been described in detail in the above method embodiments, and for the sake of brevity, the details will not be described again here.

[0532] The embodiments of this application further provide a computer-readable storage medium storing a computer program, which, when executed by a computer, implements the functions in the above method embodiments.

[0533] An embodiment of this application further provides a computer program product, which, when executed by a computer, implements the functions in the above method embodiments.

[0534] An embodiment of this application further provides a chip system. The chip system includes a processor and an interface configured to support a communication transmission device in implementing the functions of an access point or station in the above method embodiments, such as determining or processing at least one of the data and information in the above method. In a possible design, the chip system further includes a memory, which is configured to store information and data required for the above communication device. The chip system may include a chip, or may include a chip and other separate devices.

[0535] An embodiment of the present application provides a functional entity, which is configured to implement the above method for transmitting a PPDU.

[0536] It should be further understood that the terms "first," "second," "third," "fourth," and various numbers in this specification are utilized merely for distinction purposes for ease of explanation and are not intended to limit the scope of this application.

[0537] The term "and / or" in this specification should be understood to describe only the association relationship between related objects and represent that three relationships may exist. For example, A and / or B may represent the following three cases: only A exists, both A and B exist, and only B exists. In addition, the symbol " / " in this specification generally indicates an "or" relationship between related objects.

[0538] In the embodiment of this application, it should be understood that the sequence numbers of the above processes do not mean the execution order. The execution order of the processes should be determined based on the functions and internal logic of the processes, and should not constitute any limitation on the implementation process of the embodiment of this application.

[0539] Those skilled in the art may know that the units and algorithm steps, in combination with the examples described in the embodiments disclosed in this specification, may be implemented by electronic hardware or a combination of computer software and electronic hardware. Whether a function is performed by hardware or software depends on the design constraints of a specific application and technical implementation. Those skilled in the art may utilize different ways to implement the described functions for each specific application, but the implementation should not be considered as departing from the scope of this application.

[0540] Those skilled in the art can clearly understand that for the purpose of convenient and concise description, the detailed operation processes of the above systems, devices and units should be referred to the corresponding processes in the above method embodiments, and the details will not be described again here.

[0541] In some embodiments provided in this application, it should be understood that the disclosed system, device, and method may be implemented in other ways. For example, the described device embodiment is merely an example. For example, the division into units is merely a logical functional division, and may be other divisions in actual implementation. For example, multiple units or components may be combined or integrated into other systems, or some features may be omitted or not implemented. In addition, the shown or discussed mutual couplings or direct couplings or communication connections may be implemented using some interfaces. Indirect couplings or communication connections between devices or units may be implemented electronically, mechanically, or in other forms.

[0542] The units described as separate parts may or may not be physically separate, and the parts shown as units may or may not be physical units, and may be located in one place or distributed over multiple network units. Some or all of the units may be selected based on the actual requirements to achieve the implementation purpose of the embodiment.

[0543] In addition, the functional units in the embodiments of this application may be integrated into one processing unit, each of the units may exist physically alone, or two or more units may be integrated into one unit.

[0544] When a function is implemented in the form of a software functional unit and sold or used as an independent product, the function may be stored in a computer-readable storage medium. Based on such understanding, the technical implementation of this application may be essentially implemented in the form of a software product, or a part of the technical implementation may be implemented in the form of a software product. The computer software product is stored in a storage medium and includes some instructions for instructing a computer device (which may be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the method described in the embodiments of this application. The above storage medium includes any medium that can store program code, such as a USB flash drive, a removable hard disk, a Read-Only Memory (ROM), a Random Access Memory (RAM), a magnetic disk, or an optical disk.

[0545] The order of steps of the methods in the embodiments of this application may be adjusted, combined or deleted based on actual requirements.

[0546] The modules in the apparatus in the embodiments of this application can be combined, divided and removed based on actual requirements.

[0547] In summary, the above embodiments are merely intended to describe the technical implementation of this application, and are not intended to limit this application. Although this application has been described in detail in relation to the above embodiments, those skilled in the art should understand that modifications to the technical implementation recorded in the above embodiments or equivalent replacements for some technical features thereof can still be made. These modifications or replacements do not cause the essence of the corresponding technical implementation to depart from the scope of the technical implementation of the embodiments of this application.

Claims

1. 1. A method for transmitting a physical layer protocol data unit, comprising: receiving a trigger frame from an access point AP by a station STA, the trigger frame being utilized to trigger at least one STA, including the STA, to transmit an uplink physical layer protocol data unit PPDU; transmitting, by the STA, a PPDU to the AP based on the trigger frame; Including, The PPDU includes a data field and a long training field LTF used for channel estimation, the data field being carried on distributed resource units RUs assigned to the STAs, the distributed RUs including a plurality of subcarrier groups distributed in a frequency domain, one subcarrier group including one subcarrier or including at least two consecutive subcarriers, the LTF being carried on all subcarriers within a first transmission bandwidth, the first transmission bandwidth including all subcarriers corresponding to all distributed RUs assigned by the AP to the at least one STA for transmitting the uplink PPDU. method.

2. 1. A method for transmitting a physical layer protocol data unit, comprising: receiving a trigger frame from an access point AP by a station STA, the trigger frame being utilized to trigger at least one STA, including the STA, to transmit an uplink physical layer protocol data unit PPDU; transmitting, by the STA, a physical layer protocol data unit (PPDU) to the AP based on the trigger frame; Including, The PPDU includes a data field and a long training field LTF used for channel estimation, the data field being carried on distributed resource units (RUs), the distributed RUs including a plurality of subcarrier groups distributed in a frequency domain, one subcarrier group including one subcarrier or including at least two consecutive subcarriers, the LTF being carried on all subcarriers of a plurality of consecutive RUs, the plurality of consecutive RUs being consecutive RUs corresponding to the distributed RUs, each consecutive RU including a plurality of consecutive subcarriers in the frequency domain. method.

3. The method comprises: The method further includes the step of: obtaining, by the STA, the LTFs carried on all the subcarriers based on the value of an LTF sequence and a matrix P, the number of dimensions of the matrix P being determined based on the number of STAs triggered by the trigger frame, the maximum number of STAs supported by a system, and the maximum number of spatial streams supported by a single STA in the at least one STA. The method according to claim 1 or 2.

4. The step of obtaining, by the STA, the LTFs carried on all the subcarriers based on the values ​​of an LTF sequence and a matrix P, comprises: determining, by the STAs, corresponding rows from the matrix P based on an order of the STAs within the at least one STA; obtaining, by the STA, the LTFs carried on all the subcarriers based on the corresponding rows determined from the matrix P and the values ​​of the LTF sequence; Including, The method according to claim 3.

5. LTF X carried on the k-th subcarrier among all the subcarriers ｋ , and the LTF X carried on the d-th subcarrier among all the subcarriers ｄ , X ｋ =P ｉ ×LTF ｋ , and X ｄ = F x LTF ｄ Each of the following is satisfied: The k-th subcarrier is a data subcarrier, the d-th subcarrier is a pilot subcarrier, and P ｉ is the (i-1) × N ｍｓ +1 to i x N ｍｓ The first S in the th row ｉ is a row, The (i−1)×N ｍｓ +1 to i x N ｍｓ The th row is the row in the matrix P corresponding to the sequence number i of the STA, The matrix P is N ＬＴＦ ×N ＬＴＦ is an orthogonal mapping matrix of N ＬＴＦ is the number of orthogonal frequency division multiplexing OFDM symbols included in the LTF, (N ｕ ×N ｍｓ )≦N ＬＴＦ ≦(N ｍｕ ×N ｍｓ ) and N ｕ is the number of STAs triggered by the trigger frame, and N ｍｕ is the maximum number of STAs supported by the system, N ｍｓ is the maximum number of spatial streams supported by the single STA, i is the sequence number of the STA, and 1≦i≦N ｕ and S ｉ is the number of spatial streams actually transmitted by the STA having the sequence number i, and 1≦S ｉ ≦N ｍｓ and LTF ｋ is the value of the LTF sequence corresponding to the k-th subcarrier, and LTF ｄ is the value of the LTF sequence corresponding to the dth subcarrier, and F is the first row of the matrix P. The method according to claim 3 or 4.

6. i is i=(T Ｆ -T Ｌ ) / T ｃ Fills +1, T Ｆ is the duration from receipt of the trigger frame by the STA to receipt of a user information field corresponding to the STA, and T Ｌ is the duration from the reception of the trigger frame by the STA to the reception of the first user information field in the trigger frame, and T Ｃ is the length of the user information field corresponding to the STA; The method according to claim 5.

7. A chip including a processor and a memory, the memory configured to store programs or instructions, the programs or instructions being executed by the processor, the chip performing the following operations: receiving, via an interface, a trigger frame from an access point AP and being processed, the trigger frame being utilized to trigger at least one station STA to transmit an uplink physical layer protocol data unit PPDU; generating and outputting a PPDU based on the trigger frame; It becomes possible to carry out The PPDU includes a data field and a long training field LTF used for channel estimation, the data field being carried on distributed resource units RUs allocated to individual STAs, the distributed RUs including multiple subcarrier groups distributed in a frequency domain, one subcarrier group including one subcarrier or including at least two consecutive subcarriers, the LTF being carried on all subcarriers within a first transmission bandwidth, the first transmission bandwidth including all subcarriers corresponding to all distributed RUs allocated by the AP to the at least one STA for transmitting the uplink PPDU. Tips.

8. A chip including a processor and a memory, the memory configured to store programs or instructions, the programs or instructions being executed by the processor, the chip performing the following operations: receiving, via an interface, a trigger frame from an access point AP and being processed, the trigger frame being utilized to trigger at least one station STA to transmit an uplink physical layer protocol data unit PPDU; generating and outputting a PPDU based on the trigger frame; It becomes possible to carry out The PPDU includes a data field and a long training field LTF used for channel estimation, the data field being carried on distributed resource units (RUs), the distributed RUs including a plurality of subcarrier groups distributed in a frequency domain, one subcarrier group including one subcarrier or including at least two consecutive subcarriers, the LTF being carried on all subcarriers of a plurality of consecutive RUs, the plurality of consecutive RUs being consecutive RUs corresponding to the distributed RUs, each consecutive RU including a plurality of consecutive subcarriers in the frequency domain. Tips.

9. The chip performs the following operations: and obtaining the LTFs carried on all the subcarriers based on values ​​of an LTF sequence and a matrix P, the number of dimensions of the matrix P being determined based on a number of STAs triggered by the trigger frame, a maximum number of STAs supported by a system, and a maximum number of spatial streams supported by a single STA in the at least one STA. The chip according to claim 7 or 8.

10. Obtaining the LTFs carried on all the subcarriers based on values ​​of an LTF sequence and a matrix P, determining a corresponding row from the matrix P based on an order of STAs in the at least one STA; obtaining the LTFs carried on all the subcarriers based on the corresponding rows determined from the matrix P and the values ​​of the LTF sequence; Including, The chip according to claim 9.

11. LTF X carried on the k-th subcarrier among all the subcarriers ｋ , and the LTF X carried on the d-th subcarrier among all the subcarriers ｄ , X ｋ =P ｉ ×LTF ｋ , and X ｄ = F x LTF ｄ Each of the following is satisfied: The k-th subcarrier is a data subcarrier, the d-th subcarrier is a pilot subcarrier, and P ｉ is the (i-1) × N ｍｓ +1 to i x N ｍｓ The first S in the th row ｉ is a row, The (i−1)×N ｍｓ +1 to i x N ｍｓ The th row is the row in the matrix P corresponding to the sequence number i of the STA, The matrix P is N ＬＴＦ ×N ＬＴＦ is an orthogonal mapping matrix of N ＬＴＦ is the number of orthogonal frequency division multiplexing OFDM symbols included in the LTF, (N ｕ ×N ｍｓ )≦N ＬＴＦ ≦(N ｍｕ ×N ｍｓ ) and N ｕ is the number of STAs triggered by the trigger frame, and N ｍｕ is the maximum number of STAs supported by the system, N ｍｓ is the maximum number of spatial streams supported by the single STA, i is the sequence number of the STA, and 1≦i≦N ｕ and S ｉ is the number of spatial streams actually transmitted by the STA having the sequence number i, and 1≦S ｉ ≦N ｍｓ and LTF ｋ is the value of the LTF sequence corresponding to the k-th subcarrier, and LTF ｄ is the value of the LTF sequence corresponding to the dth subcarrier, and F is the first row of the matrix P. The chip according to claim 9 or 10.

12. i is i=(T Ｆ -T Ｌ ) / T ｃ Fills +1, T Ｆ is the duration from receipt of the trigger frame by the STA to receipt of a user information field corresponding to the STA, and T Ｌ is the duration from the reception of the trigger frame by the STA to the reception of the first user information field in the trigger frame, and T Ｃ is the length of the user information field corresponding to the STA; The chip of claim 11.

13. A communications device including a processor, the processor coupled to a memory, the memory configured to store a program or instructions, the program or instructions being executed by the processor enabling the device to perform a method according to any one of claims 1 to 6.

14. A readable storage medium, the readable storage medium storing a computer program or instructions, the computer program or instructions, when executed, enabling a computer to carry out a method according to any one of claims 1 to 6.

15. A computer program comprising computer program instructions, said computer program instructions enabling a computer to carry out the method according to any one of claims 1 to 6.

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