A method and apparatus for transmitting and receiving retransmission data

Abstract

The application discloses a kind of sending method of retransmission data, receiving method and related device, belong to communication technical field.In the present scheme, sending end generates retransmission codeword based on the information bits of each codeword corresponding to erroneous MPDU, wherein, retransmission codeword includes: the partial bits of information bits are contained in the codeword in erroneous MPDU.For the codeword of the partial bits of information bits contained in erroneous MPDU, sending end sends out after the correct information bits in this codeword are punctured, so that receiving end can directly combine the LLR of retransmission MPDU codeword and the LLR of the codeword of last erroneous MPDU and decode or jointly decode, improves transmission efficiency and transmission reliability.

Description

Technical Field

[0001] This application relates to the field of communication technology, and in particular to a method for transmitting and receiving retransmitted data, and an apparatus thereof. Background Technology

[0002] In communication systems, signal transmission failures can occur due to the time-varying characteristics of wireless channels and multipath fading. Error control is typically achieved using methods such as Forward Error Correction (FEC) coding techniques and Automatic Repeat-reQuest (ARQ). For example, in a WLAN (Wireless Local Area Network), when an access point (AP) sends data to a station (STA), if the STA successfully receives the data, it sends an acknowledgment (ACK) frame back to the AP; if the STA fails to receive the data, it does not send any frame. If the AP does not receive any feedback, it retransmits the data, thus controlling errors through retransmission.

[0003] Building upon ARQ, standards such as LTE (Long Term Evolution) introduced Hybrid ARQ (HARQ). The receiver pre-stores the data received the first time. When retransmitted data is received, the data received in the first and retransmitted sessions are combined, thereby increasing the decoding success rate. Because HARQ can further increase the success rate of retransmitted data reception, wireless networks typically employ HARQ mechanisms in deep fading regions or edge regions. This mechanism often allows the transmitter to use more sophisticated modulation and coding schemes (MCS), improving transmission efficiency.

[0004] Because retransmission requires a certain amount of buffering to store the data that needs to be merged, previous standards such as 802.11a / g / n / ac / ax did not introduce a retransmission mechanism. In future WLAN systems, such as next-generation WLANs and 802.11be systems, due to improved hardware performance, retransmission technology, which can improve transmission reliability and efficiency, is likely to be selected as one of the technologies in the next-generation WiFi standard. Therefore, designing a retransmission technology suitable for WLAN systems is crucial. Summary of the Invention

[0005] This application provides a data retransmission method and apparatus, which can improve the reliability and transmission efficiency of wireless communication systems. The technical solution is as follows:

[0006] A first aspect provides a method for transmitting retransmitted data, for use at a transmitting end, the method comprising: determining a first MPDU that needs to be retransmitted from a previously transmitted Aggregated Media Intervention Control Protocol Data Unit (A-MPDU), the first MPDU being contained in a first A-MPDU subframe of the A-MPDU; at least one prior LDPC codeword encoded in the first A-MPDU subframe including the first LDPC codeword, the information bits of the first LDPC codeword corresponding to a first set of information bits in the first A-MPDU subframe and a second set of information bits not contained in the first A-MPDU subframe; obtaining a second LDPC codeword based on the information bits of the first LDPC codeword; at least one retransmitted LDPC codeword encoded in the first A-MPDU subframe, the at least one retransmitted LDPC codeword including a punctured codeword, the punctured codeword being all or part of the encoded bits of the second set of information bits in the second LDPC codeword after puncturing.

[0007] In one possible implementation, the at least one retransmitted LDPC codeword further includes at least one unpunctured codeword, wherein all information bits corresponding to the at least one unpunctured codeword are contained in the first A-MPDU subframe.

[0008] In one possible implementation, the information bits of the first LDPC codeword correspond to a first set of information bits in the first A-MPDU subframe and a second set of information bits not included in the first A-MPDU subframe, including: the information bits of the first LDPC codeword are information bits after scrambling the first set of information bits and the second set of information bits using a scrambling sequence; or, the information bits of the first LDPC codeword are the first set of information bits and the second set of information bits.

[0009] In one possible implementation, obtaining the second LDPC codeword based on the information bits of the first LDPC codeword includes: obtaining the previously transmitted first LDPC codeword as the second LDPC codeword; or, encoding the information bits of the first LDPC codeword using retransmission coding parameters to obtain the second LDPC codeword; wherein the retransmission coding parameters are the same as the coding parameters (code length and code rate) used in the first LDPC codeword; or encoding the information bits of the first LDPC codeword using a retransmission check matrix to obtain the second LDPC codeword; wherein the retransmission check matrix has a preset relationship with the check matrix of the first LDPC codeword.

[0010] In one possible implementation, the information bits of the first LDPC codeword include: a first information bit set and a second information bit set; obtaining the second LDPC codeword based on the information bits of the first LDPC codeword includes:

[0011] The information bits of the first LDPC codeword are scrambled using a retransmission scrambling sequence to obtain scrambled bits to be encoded; the scrambled information bits to be encoded are then encoded using retransmission coding parameters to obtain the second LDPC codeword; wherein the retransmission scrambling sequence is the same as the scrambling sequence used to scramble the information bits of the first LDPC codeword; and the retransmission coding parameters are the same as the coding parameters of the first LDPC codeword; or,

[0012] The information bits of the first LDPC codeword are scrambled using a retransmission scrambling sequence to obtain scrambled bits to be encoded; the scrambled information bits to be encoded are then encoded using a retransmission parity check matrix to obtain the second LDPC codeword; wherein the retransmission scrambling sequence is the same as the scrambling sequence used to scramble the information bits of the first LDPC codeword in a previous transmission; and the retransmission parity check matrix has a preset relationship with the parity check matrix of the first LDPC codeword.

[0013] In one possible implementation, at least one retransmission codeword encoded by the first A-MPDU subframe is carried in a Physical Layer Protocol Data Unit (PPDU); the preamble of the PPDU includes one or more of the following:

[0014] MPDU retransmission indication, wherein the MPDU retransmission indication takes a first value to indicate that the PPDU includes retransmitted MPDUs; modulation and coding scheme indication, wherein the modulation and coding scheme indication is a special value to indicate that the PPDU includes only retransmitted MPDUs; retransmitted MPDU length indication, to indicate the total length of the A-MPDU subframes including retransmitted MPDUs in the PPDU; scrambler seed indication, to indicate the scrambler seed used for scrambling the retransmitted MPDUs.

[0015] Secondly, a method for receiving retransmitted data is provided for a receiving end, comprising: determining a first MPDU that needs to be retransmitted in a previously transmitted first aggregated Media Intervention Control Protocol Data Unit (A-MPDU), the first MPDU being contained in a first A-MPDU subframe; at least one prior LDPC codeword encoded in the first A-MPDU subframe including a first LDPC codeword, the information bits of the first LDPC codeword corresponding to a first set of information bits in the first A-MPDU subframe and a second set of information bits not contained in the first A-MPDU subframe; receiving at least one retransmitted LDPC codeword encoded in the first A-MPDU subframe retransmitted by the sending end, the at least one retransmitted codeword including a punctured codeword, the punctured codeword being all or part of the encoded bits of the second set of information bits of a second LDPC codeword after puncturing; the second LDPC codeword being generated based on the information bits of the first LDPC codeword; and performing combined decoding or joint decoding on the at least one retransmitted LDPC codeword and the previously received at least one prior LDPC codeword to obtain the first A-MPDU subframe.

[0016] In one possible implementation, at least one retransmitted LDPC codeword further includes at least one unpunctured codeword, wherein all information bits corresponding to the at least one unpunctured codeword are contained in the first A-MPDU subframe.

[0017] In one possible implementation, the information bits of the first LDPC codeword correspond to a first set of information bits in the first A-MPDU subframe and a second set of information bits not included in the first A-MPDU subframe. Combined decoding or joint decoding includes: padding the second set of information bits into the punctured codeword to obtain the second LDPC codeword; using retransmission decoding parameters to decode the at least one retransmitted LDPC codeword and the at least one previously received pre-transmitted LDPC codeword to obtain the first A-MPDU subframe; wherein the retransmission decoding parameters are the same as the decoding parameters used to decode the previously transmitted first LDPC codeword; or,

[0018] In one possible implementation, the information bits of the first LDPC codeword are information bits obtained by scrambling the first information bit set and the second information bit set using a scrambling sequence; combined decoding or joint decoding is performed, including:

[0019] The second information bit set is padded to the punched codeword to obtain the second LDPC codeword; the at least one retransmitted LDPC codeword and the at least one previously received pretransmitted LDPC codeword are merged or jointly decoded using retransmission decoding parameters to obtain the scrambled first A-MPDU subframe; the scrambled first A-MPDU subframe is descrambled using a retransmission random scrambling sequence to obtain the descrambled first A-MPDU subframe; wherein the retransmission decoding parameters are the same as the decoding parameters used to decode the previously received first A-MPDU subframe; and the retransmission scrambling sequence is the same as the scrambling sequence used to descramble the previously received scrambled first A-MPDU subframe.

[0020] In one possible implementation, the merged decoding or joint decoding further includes: deleting the second set of information bits from the information bits after merged decoding or joint decoding to obtain the first A-MPDU subframe.

[0021] In one possible implementation, at least one retransmission codeword corresponding to the first A-MPDU encoding is carried in a physical layer protocol data unit; the preamble of the PPDU includes a combination of one or more of the following: an MPDU retransmission indicator, wherein the MPDU retransmission indicator takes a first value to indicate that the PPDU includes a retransmitted MPDU; a modulation and coding scheme indicator, wherein the modulation and coding scheme indicator is a special value to indicate that the PPDU includes only retransmitted MPDUs; a retransmission MPDU length indicator to indicate the total length of the A-MPDU subframes including the retransmitted MPDUs in the PPDU; and a scrambler seed indicator to indicate the scrambler seed used for scrambling the retransmitted MPDUs.

[0022] Thirdly, a method for transmitting a PPDU is provided, applied at a transmitting end, comprising: generating an aggregated Media Access Control Protocol Data Unit (A-MPDU), wherein the A-MPDU includes at least one first A-MPDU subframe and at least one second A-MPDU subframe; one first A-MPDU subframe includes a retransmitted Media Access Control Protocol Data Unit (MPDU); one second A-MPDU subframe includes an initial transmitted MPDU; the total length of the at least one first A-MPDU subframe is a first length L1; the total length of the at least one second A-MPDU subframe is a second length L2; and the total length of the A-MPDU subframe is a third length L3; determining a first encoding parameter based on the encoding parameters of a previously transmitted first A-MPDU subframe, and determining a second encoding parameter based on the second length L2; encoding and encapsulating the at least one first A-MPDU subframe and the at least one second A-MPDU subframe into a data field of a Physical Layer Protocol Data Unit (PPDU) using the first encoding parameter and the second encoding parameter respectively; and transmitting the PPDU.

[0023] In one possible implementation, the first encoding parameters include an encoding code length and an encoding code rate, the encoding code length and encoding code rate being the same as those of at least one previously transmitted first A-MPDU subframe; or,

[0024] The first encoding parameter includes a check matrix, which has a preset relationship with the check matrix of the at least one previously transmitted first A-MPDU subframe.

[0025] In one possible implementation, the data field of the PPDU includes: N1 OFDM symbols corresponding to the at least one first A-MPDU subframe, and N2 OFDM symbols corresponding to the at least one second A-MPDU subframe; determining the second coding parameter based on the second length L2 includes: determining the number N2 of OFDM symbols corresponding to the at least one second A-MPDU subframe based on the second length L2; and determining the number N of coding bits required for the at least one second A-MPDU subframe based on the number N2 of OFDM symbols. avbit Based on N avbit Determine the second encoding parameter.

[0026] In one possible implementation, N avbit =N2N CBPS

[0027] When the STBC method is used, m STBC =2, otherwise m STBC =1; N DBPSThe number of information bits that each OFDM symbol can carry; N service N represents the length of the service field in the PPDU structure. CBPS The number of coded bits that each OFDM symbol can carry.

[0028] In one possible implementation, based on N avbit Determining the second encoding parameter includes: determining the encoding code length included in the second encoding parameter based on the preset correspondence between encoded bits and code length.

[0029] In one possible implementation, the leading edge of the PPDU includes a length indicator for indicating either the first length L1 or the second length L2.

[0030] Fourthly, a method for receiving a PPDU is provided, applied at a receiving end, characterized in that it includes: receiving a Physical Layer Protocol Data Unit (PPDU), wherein the data field of the PPDU includes a first part encoded by at least one first A-MPDU subframe using a first encoding parameter, and a second part encoded by at least one second A-MPDU subframe using a second encoding parameter; one first A-MPDU subframe includes a retransmitted MPDU, and one second A-MPDU subframe includes an initial transmitted MPDU; wherein the total length of the at least one first A-MPDU subframe is a first length L1; the total length of the at least one second A-MPDU subframe is a second length L2, and the total length of the A-MPDU subframe is a third length L3; decoding the PPDU using the first encoding parameter and the second encoding parameter respectively to obtain the at least one first A-MPDU subframe and the at least one second A-MPDU subframe; wherein the first encoding parameter is determined based on the encoding parameters of the previously transmitted first A-MPDU subframe, and the second encoding parameter is determined based on the second length L2.

[0031] In one possible implementation, the second encoding parameter includes an encoding code length and an encoding code rate, which are the same as the encoding code length and encoding code rate of the at least one previously transmitted first A-MPDU subframe; or, the first encoding parameter includes a parity check matrix, which has a preset relationship with the parity check matrix of the at least one previously transmitted first A-MPDU subframe.

[0032] In one possible implementation, the number of OFDM symbols N2 corresponding to the at least one second MPDU is determined based on the second length L2; the number of encoded bits N required for the at least one second MPDU is determined based on the number of OFDM symbols N2. avbit Based on N avbit Determine the second encoding parameter.

[0033] In one possible implementation, N avbit =N2N CBPS

[0034] When the STBC method is used, m STBC =2, otherwise m STBC =1; N DBPS The number of information bits that each OFDM symbol can carry; N service N represents the length of the service field in the PPDU structure. CBPS The number of coded bits that each OFDM symbol can carry.

[0035] In one possible implementation, based on N avbit Determining the second encoding parameter includes: determining the encoding code length included in the second encoding parameter based on the preset correspondence between encoded bits and code length.

[0036] In one possible implementation, the leading edge of the PPDU includes a length indicator for indicating either the first length L1 or the second length L2;

[0037] The method further includes: determining the second length L2 based on a length indication.

[0038] In one possible implementation, the method further includes: determining the second length L2 based on the L-Length field in the preamble of the PPDU.

[0039] Fifthly, a transmitting apparatus is provided for a transmitting end, which implements the methods and functions of the transmitting end involved in any of the first or third aspects described above. The transmitting apparatus includes: a processing module, a transmitting module, a receiving module, and optionally, a storage module.

[0040] Sixthly, a receiving device is provided for a transmitting end, the receiving device being used to implement the methods and functions of the transmitting end involved in any of the second or fourth aspects described above. The receiving device includes: a processing module, a transmitting module, a receiving module, and optionally, a storage module.

[0041] A seventh aspect provides a transmitting apparatus for a transmitting end, comprising: a memory and a processor, the memory and the processor being coupled, the memory being used to store a computer program, the computer program including program instructions; and the processor being used to invoke the program instructions to implement the method as described in either the first or third aspect.

[0042] Eighthly, a receiving apparatus is provided for a receiving end, comprising: a memory and a processor, the memory and the processor being coupled, the memory being used to store a computer program, the computer program including program instructions; the processor being used to invoke the program instructions to implement the data transmission method as described in either the second or fourth aspect.

[0043] A ninth aspect provides a computer-readable storage medium storing a computer program comprising at least one piece of code executable by a computer to control the computer to perform a data transmission method as described in any one of the first to fourth aspects.

[0044] In a tenth aspect, a computer program is provided, which, when executed by a computer, performs the data transmission method as described in any one of the first to fourth aspects.

[0045] Optionally, the computer program may be stored wholly or partially on a storage medium packaged with the processor, or it may be stored wholly or partially on a memory not packaged with the processor.

[0046] Eleventhly, a chip is provided, including a processor for retrieving and executing instructions stored in a memory, causing a communication device on which the chip is installed to perform the methods of the foregoing aspects.

[0047] In a twelfth aspect, embodiments of this application also provide another chip, which can be part of a receiver or transmitter. The chip includes an input interface, an output interface, and a circuit. The input interface, the output interface, and the circuit are connected through an internal connection path. The circuit is used to execute the methods in the examples above.

[0048] On the thirteenth side, another chip is provided, including: an input interface, an output interface, a processor, and optionally, a memory. The input interface, the output interface, the processor, and the memory are connected through an internal connection path. The processor is used to execute code in the memory. When the code is executed, the processor is used to perform the methods in the above aspects.

[0049] In a fourteenth aspect, an apparatus is provided for implementing the methods described above.

[0050] In a fifteenth aspect, a communication system is provided, comprising: a transmitting end and at least one receiving end, the transmitting end comprising a transmitting device as described in the fifth aspect, and the receiving end comprising a receiving device as described in the sixth aspect; or, the transmitting end comprising a transmitting device as described in the seventh aspect, and the receiving end comprising a receiving device as described in the eighth aspect.

[0051] The technical solution of this application realizes MPDU retransmission based on the A-MPDU structure, which can support retransmission in WLAN, further improve the transmission reliability and transmission efficiency of WLAN system, and enable the receiver to directly merge and decode or jointly decode the LLR of the retransmitted codeword with the LLR of the previously transmitted codeword, reducing the complexity of the receiver, saving the decoding time of the receiver, and improving the transmission efficiency. Attached Figure Description

[0052] Figure 1 This is a schematic diagram illustrating an application scenario provided in an embodiment of this application;

[0053] Figure 2 This is a schematic diagram of the frame structure of an A-MPDU provided in an embodiment of this application;

[0054] Figure 3 This is a schematic diagram of the structure of a retransmission MPDU provided in an embodiment of this application;

[0055] Figure 4 This is a flowchart illustrating a method for sending retransmitted data provided in an embodiment of this application;

[0056] Figure 5a This is a schematic diagram of the structure of a previously transmitted A-MPDU provided in an embodiment of this application;

[0057] Figure 5b This is a schematic diagram of the structure of a retransmission A-MPDU provided in an embodiment of this application;

[0058] Figure 5c This is a schematic diagram of another retransmission A-MPDU provided in an embodiment of this application;

[0059] Figure 6 This is a flowchart illustrating a method for receiving retransmitted data provided in an embodiment of this application;

[0060] Figure 7 This is a flowchart illustrating another method for sending retransmitted data provided in an embodiment of this application;

[0061] Figure 8a This is a schematic diagram of another previously transmitted A-MPDU provided in an embodiment of this application;

[0062] Figure 8b This is a schematic diagram of another retransmission A-MPDU provided in the embodiments of this application;

[0063] Figure 8c This is a schematic diagram of another retransmission A-MPDU provided in the embodiments of this application;

[0064] Figure 9 This is a flowchart illustrating another method for receiving retransmitted data provided in an embodiment of this application;

[0065] Figure 10 This is a flowchart illustrating a PPDU transmission method provided in an embodiment of this application;

[0066] Figure 11 This is a schematic diagram of the structure of a PPDU provided in an embodiment of this application;

[0067] Figure 12 This is a flowchart illustrating a method for receiving a PPDU provided in an embodiment of this application;

[0068] Figure 13 This is a schematic diagram of the structure of a transmitting device provided in an embodiment of this application;

[0069] Figure 14 This is a schematic diagram of the structure of a receiving device provided in an embodiment of this application;

[0070] Figure 15 This is a schematic diagram of another transmitting device provided in an embodiment of this application;

[0071] Figure 16 This is a schematic diagram of another receiving device provided in an embodiment of this application. Detailed Implementation

[0072] To make the objectives, technical solutions, and advantages of this application clearer, the embodiments of this application will be described in further detail below with reference to the accompanying drawings.

[0073] In wireless communication systems, signal transmission failures can occur due to the time-varying characteristics of wireless channels and multipath fading. Therefore, methods such as forward error correction (FEC) coding techniques and automatic repeat-request (ARQ) are commonly used for error control.

[0074] Retransmission technology refers to the sending end retransmitting data that was previously not successfully or correctly received by the receiving end. Retransmission technologies can include ARQ and HARQ. Compared to ARQ, HARQ can further increase the success rate of retransmitted data reception. HAQR technology in LTE generally includes two implementation methods: Chase Combining (CC) and Incremental Redundancy (IR).

[0075] Chase-and-go, also known as soft combining, occurs during CC-type retransmissions. The sender retransmits the same coded bits as the previously erroneously transmitted bits, including information bits and parity bits. The receiver combines the retransmitted bits with the previously received bits. Specifically, the LLR (Log-Likelihood Ratio) of the coded bits before decoding the erroneously transmitted bits is combined with the LLR of the currently received bits, and then the combined LLR value is used for decoding.

[0076] During incremental redundancy retransmission, the sender retransmits retransmitted coded bits, which are different from the previously transmitted coded bits. For example, the sender may retransmit additional parity bits, retransmit newly generated parity bits, retransmit information bits and a portion of the parity bits, or retransmit another part of the coded codeword. These retransmitted coded bits may have different redundant versions. The receiver then decodes the original information together with the information from the additionally received retransmitted coded bits. Because HAQR IR retransmits fewer bits, it is more efficient than HARQ CC, but it requires a complete redesign of the codebook, increasing its complexity.

[0077] In wireless communication systems, such as cellular communication systems supporting LTE or 5G, the transmitting end sends a single data packet, which includes only one data sub-packet and does not aggregate multiple data sub-packets. If the data packet is transmitted incorrectly, received incorrectly, or not successfully received, the transmitting end first encodes the data packet to be retransmitted, then scrambles the encoded bits, performs constellation point mapping modulation, uploading frequency, etc., and finally transmits it to the receiving end through the transmit antenna. After receiving the signal, the receiving end correspondingly performs constellation point demapping, descrambling, and combines or jointly decodes the LLR of each descrambled encoded bit with the LLR of each previously received encoded bit to decode the information bits of the data packet. For cases where data packets aggregate multiple data sub-packets, or data frames aggregate multiple data subframes, how to retransmit some subframes in multiple data subframes to improve transmission reliability and efficiency remains an unsolved technical problem. Therefore, embodiments of this application provide a method and apparatus for retransmitting data, thereby improving the transmission efficiency and reliability of wireless communication systems.

[0078] The solutions in this application are applicable to various wireless communication systems, such as cellular communication systems and wireless local area network (WLAN) communication systems. Cellular communication systems can support multiple communication protocols, such as the 5G NR communication standard protocol, and can also support future cellular communication protocols; WLAN communication systems can also support multiple WLAN communication protocols, such as the Institute of Electrical and Electronics Engineers (IEEE) 802.11ax protocol, and next-generation or even more recent versions of the IEEE 802.11ax protocol.

[0079] The solutions in this application embodiment can be applied to communication between the transmitting end and the receiving end in the aforementioned communication system. The transmitting end and the receiving end can be wireless communication devices or chips supporting wireless communication, such as base stations, terminals, or chips within base station terminals in cellular communication systems, or access points and sites in WLAN communication systems, or chips within access points and sites. For example, terminals and sites can also be called user terminals, user equipment, access devices, subscriber stations, subscriber units, mobile stations, user agents, user equipment, or other names. User terminals can include various handheld devices, vehicle-mounted devices, wearable devices, computing devices, or other processing devices connected to a wireless modem with wireless communication capabilities, as well as various forms of user equipment (UE), mobile station (MS), terminal, terminal equipment, portable communication devices, handheld devices, portable computing devices, entertainment devices, gaming devices or systems, global positioning system devices, or any other suitable devices configured for network communication via wireless media, etc. Base stations or access points can include various forms of macro base stations, micro base stations, relay stations, wireless access points, etc.

[0080] For ease of description, this application uses WLAN as an example for illustration. A WLAN may include multiple Basic Service Sets (BSS). Figure 1A basic service set shown includes access point (AP) stations and non-access point stations (Non-AP STAs). Access point stations are typically referred to simply as access points (APs), and non-access point stations are typically referred to simply as stations (STAs). Each basic service set can contain one AP and multiple STAs associated with that AP. An access point is a device with wireless transceiver capabilities that can provide services to stations. A station is a device with wireless transceiver capabilities that can access a wireless local area network (WLAN) based on an access point. Therefore, in this application scenario, the sending end can be either an access point or a station, and the receiving end can also be either an access point or a station. That is, the method in this application embodiment can be used for communication between access points, communication between access points and stations, and communication between stations.

[0081] For ease of understanding, the embodiments of this application first describe the general data transmission and reception process. Due to the different orders of scrambling and decoding, the data transmission and reception process can be divided into two cases: the first process is to encode first and then scramble; the second process is to scramble first and then encode.

[0082] One implementation of the first process: The transmitting end generates a MAC frame at the Media Access Control (MAC) layer. The MAC frame includes multiple information bits and is passed to the Physical Layer (PHY layer). At the PHY layer, the transmitting end encodes, scrambles, and maps constellation points to the MAC frame, then adds a Physical Layer preamble and encapsulates it into a Physical Protocol Data Unit (PPDU) or Physical Layer Data Packet, which is then transmitted via the antenna. Upon receiving the PPDU, the receiving end performs corresponding processing at the PHY layer, including constellation point demapping, descrambling, and decoding, to obtain the MAC frame and thus the information bits. Another implementation of the second process: The transmitting end can first scramble the MAC frame and then encode it to obtain a PHY data unit, which is then transmitted via the antenna. Correspondingly, the receiving end first decodes the received PHY data unit and then descrambles it to obtain the MAC frame.

[0083] It should be noted that the transmitting and receiving ends may also include other baseband processing and radio frequency processing, etc. These will not be described in detail in the embodiments of this application. In the data transmission and reception process, various encoding and decoding types can be used, such as block coding and convolutional coding. For ease of description, the embodiments of this application use low-density parity code (LDPC) encoding as an example. The method of the embodiments of this application can also be used for data transmission and reception using other block codes.

[0084] In WLANs, APs and STAs exchange data, control signaling, or management signaling via Media Intervention Control Protocol Data Units (MPDUs). An MPDU typically includes a frame header, frame body, and frame check sequence (FCS). The frame body carries data, management information, or control information passed down from the upper layer. For some specific types of MPDUs, such as acknowledgment frames, the frame body may be absent. The FCS is used to verify whether the MPDU was transmitted correctly. The frame header may include at least one of the following fields: Frame Control, Duration / ID, Address, Sequence Control, Quality of Service (QoS) Control, and High Throughput Control (HTControl). The interpretation of each field can be found in the IEEE 802.11 protocol; this embodiment will not be elaborated upon here.

[0085] To improve WLAN performance, frame aggregation technology is currently used at the MAC layer to aggregate multiple MPDUs into a single aggregated MPDU (A-MPDU). The A-MPDU combines multiple MPDUs and transmits them through a unified physical layer preamble, effectively reducing channel contention and the overhead of the physical layer preamble, thus improving transmission efficiency. Figure 2 This is a structural diagram of the A-MPDU in the IEEE 802.11 standard, as shown below. Figure 2 As shown, an A-MPDU consists of n A-MPDU subframes, where n is an integer greater than or equal to 1. Optionally, see [link to relevant documentation]. Figure 2The A-MPDU may also include an end-of-frame (EOF) padding field located after n A-MPDU subframes. Each A-MPDU subframe includes an MPDU delimiter and an MPDU. Optionally, the A-MPDU subframe may also include a padding field. The MPDU delimiter is used to separate multiple aggregated MPDUs.

[0086] Specifically, an A-MPDU containing only one delimiter and one MPDU is also called a Single MPDU (S-MPDU, Single Media Access Control Protocol Data Unit). The 802.11 standard uses a simple Ack acknowledgment frame mechanism for MPDUs and S-MPDUs, indicating whether the MPDU or S-MPDU was successfully received by sending an acknowledgment frame. For A-MPDUs containing at least two MPDUs, a Block Ack or Multi-STA Block Ack frame is used for acknowledgment. Both types of Block Ack frames include a bitmap, where each bit corresponds to an MPDU, indicating whether the corresponding MPDU in the A-MPDU was correctly received. A 1 indicates that the corresponding MPDU was correctly received, and a 0 indicates that the corresponding MPDU was incorrectly received. If none of the MPDUs in the aggregated A-MPDU frame were correctly received or were not received at all, the STA does not send acknowledgment information.

[0087] Optionally, the MPDU delimiter includes at least one of the following fields: EOF field, reserved field, MPDU length field, Cyclic Redundancy Code (CRC) field, and delimiter signature field. This application embodiment does not limit the content of the MPDU delimiter or the order of the fields.

[0088] Regarding the structure of the A-MPDU described above, one possible implementation method for retransmitting data is provided:

[0089] Based on existing MPDU acknowledgment feedback methods, if the receiver reports an error in one or more previously transmitted MPDUs, the transmitter typically retransmits the MPDU, encodes it, and then sends it again. However, even if the transmitter encodes the retransmitted MPDU using the same code length, code rate, and parity check matrix (LDPC), the retransmitted LDPC codeword will differ from the previously transmitted LDPC codeword because the information bits in each LDPC codeword are misaligned or different. Therefore, the receiver cannot perform LLR merging or joint decoding on the retransmitted encoded bits and the previously received encoded bits. Figure 3 A schematic diagram of a retransmission MPDU is shown. For example, assuming the LDPC codeword length is 14 and the code rate is 1 / 2, that is, the corresponding information bit length is 7 and the parity bit length is 7, such as... Figure 3 As shown, LDPC codewords 3, 5, 7, and 9 span two MPDUs (here, the A-MPDU subframe is simply referred to as MPDU). If MPDU2 and MPDU3 are received incorrectly, the transmitter needs to re-LDPC encode them. The re-encoded LDPC codewords are based on information bits 16 to 22, while the first LDPC codeword associated with the previously incorrectly received MPDU2 is generated based on information bits 15 to 21. Due to the different information bits, the generated check bits are also different. Therefore, the receiver cannot combine or jointly decode the LLR of the encoded bits of the retransmitted LDPC codeword with the LLR of the encoded bits of the previously transmitted LDPC codeword. It is worth noting that the parameters of the LPDC codewords in the example above are only examples. The 802.11n / ac / ax protocol uses three LDPC code lengths: 648, 1296, and 1944. The three code lengths of LDPC codewords each contain four code rates: 1 / 2, 2 / 3, 3 / 4, and 5 / 6.

[0090] The following detailed description, in conjunction with more accompanying drawings, provides several other embodiments of this application.

[0091] Example 1 describes in detail the first process described above (i.e., the transmitting end encodes the MAC layer frame first and then scrambles it, and correspondingly, the receiving end descrambles the PHY layer data unit first and then decodes it), providing a method for transmitting retransmitted data to improve the transmission reliability and efficiency of the wireless communication system.

[0092] Figure 4 This invention illustrates a flowchart of a method for transmitting retransmitted data according to an embodiment of this application. The method includes:

[0093] S101: Transmit Aggregated Media Intervention Control Protocol Data Unit (A-MPDU), wherein the A-MPDU includes at least one A-MPDU subframe.

[0094] After the A-MPDU is assembled at the MAC layer, it is passed to the PHY layer. Optionally, at the PHY layer, the transmitter performs LDPC encoding, scrambling, constellation point mapping, and other operations on the A-MPDU, and then adds physical layer preambles (physical layer preambles usually encapsulate non-HT, non-high throughput (traditional) preambles) and next-generation physical layer preambles to form PPDU, which is then transmitted via the transmitter's antenna.

[0095] Optionally, the A-MPDU includes at least two A-MPDU subframes; for example... Figure 5a The A-MPDU shown comprises five A-MPDU subframes: A-MPDU subframe 1 to A-MPDU subframe 5. It is worth noting that this method still applies to cases where the A-MPDU contains only one subframe.

[0096] Optionally, it also includes scrambling at least one LDPC codeword using a scrambling sequence. In step S101, the scrambling operation at the transmitting end occurs after encoding. Optionally, the period of the scrambling sequence can be 127 bits, for example, a 127-bit sequence is 00001110 11110010 11001001 00000010 00100110 00101110 10110110 0000110011010100 11100111 10110100 00101010 11111010 01010001 10111000 1111111. One method of scrambling is as follows: The encoded bits of at least one LDPC codeword, from the first bit to the last bit, are XORed with a scrambling sequence with a period of 127 bits. For example, if at least one LDPC codeword includes 200 encoded bits, the first 127 encoded bits are XORed with a 127-bit scrambling sequence, and then the last 73 encoded bits are XORed with the first 73 bits of the 127-bit scrambling sequence to obtain the scrambled bit sequence. For ease of description, the encoding parameters used to encode the A-MPDU in step S101 can be called the pre-transmission encoding parameters, and the scrambling sequence used to scramble the A-MPDU in step S101 can be called the pre-transmission scrambling sequence.

[0097] The scheme in this application embodiment is applicable to both A-MPDUs containing multiple MPDUs and A-MPDUs containing only one MPDU. Furthermore, the transmitting end encapsulates the encoded A-MPDU into a single physical layer protocol data unit (PPDU). This PPDU can be transmitted in single-user (SU) mode or multi-user (MU) mode. Multi-user mode can be further divided into OFDMA transmission, MU-MIMO mode, or a hybrid mode of OFDMA and MU-MIMO.

[0098] Optionally, S102: Receive acknowledgment feedback information sent by the receiver. The acknowledgment feedback information is used to indicate which MPDUs in the A-MPDU were not successfully received.

[0099] Upon receiving the A-MPDU, the receiving end sends an acknowledgment feedback message to the sending end based on its actual reception status, informing the sending end which MPDUs in this transmission were not successfully received. The sending end, combining the acknowledgment feedback frame with its own transmission status, determines which MPDUs to retransmit. Unsuccessful reception can also be referred to as reception failure or transmission failure. Optionally, in step S102, the receiving end reports that at least one first MPDU was not successfully received.

[0100] This application does not limit the method of sending acknowledgment feedback by the receiving end. The receiving end can inform the sending end which MPDUs were not successfully received or failed to be received by means of negative acknowledgment (NACK) information, or bitmaps in block acknowledgment (BACK) frames, or bitmaps in multi-STA block acknowledgment (MSTA) frames. However, the corresponding physical layer preamble was correctly received or the sending and receiving ends of all MPDUs can be identified. In other words, it informs the sending end which MPDUs can be retransmitted based on HARQ rules. NACK can be a single frame or a part of a multi-STA block acknowledgment (MSTA) frame. Unlike the current acknowledgment frames and no-reply methods, NACK informs the sending end that all MPDUs sent in this transmission were not correctly received. All MPDUs can be one or more, but the corresponding physical layer preamble was correctly received or the sending and receiving ends of all MPDUs in this transmission can be identified.

[0101] For example Figure 5aAs shown, MPDU2 in A-MPDU subframe 2 and MPDU2 in A-MPDU subframe 3 were not successfully received. The acknowledgment feedback frame carries indication information to indicate that MPDU2 and MPDU3 in the A-MPDU were not successfully received. For example, if the indication information is a bitmap including 5 bits, where the first to fifth bits correspond to MPDUs in A-MPDU subframes 1 to 5 respectively, in one example, a value of 0 indicates unsuccessful reception and a value of 1 indicates successful reception, then the value of these 5 bits can be 10011; of course, a value of 1 can also be set to indicate unsuccessful reception and a value of 0 to indicate successful reception, and the embodiments of this application are not limited.

[0102] When all MPDUs included in an A-MPDU fail to be received, there are several feedback methods. The first feedback method is to not reply, meaning the receiver does not send an acknowledgment message to the sender; the receiver is then aware that all MPDUs were not successfully received. The second feedback method, unlike the first, uses a NACK message as acknowledgment feedback to inform the receiver that all MPDUs included in the sent A-MPDU failed to be received. Optionally, the NACK message can be encapsulated as a separate frame or can be part of a Multi-STABlock Ack frame to indicate that all MPDUs included in the sent A-MPDU failed to be received.

[0103] S103: Determine at least one first MPDU in the previously transmitted Aggregated Media Intervention Control Protocol Data Unit (A-MPDU) that needs to be retransmitted;

[0104] At least one first MPDU that needs to be retransmitted is contained in at least one first A-MPDU subframe of the previously transmitted A-MPDU.

[0105] The previously transmitted A-MPDU (or A-MPDU subframe) refers to the A-MPDU (or A-MPDU subframe) transmitted before step S103, i.e., the A-MPDU (or A-MPDU subframe) transmitted in step S101. The A-MPDU (or A-MPDU subframe) transmitted in step S101 can be the A-MPDU (or A-MPDU subframe) of the previous transmission retransmitted in S103, or it can be the A-MPDU (or A-MPDU subframe) of the first transmission. This application does not limit the scope of the embodiments. For ease of description, the A-MPDU (or A-MPDU subframe) transmitted in step S101 is referred to herein as the previously transmitted A-MPDU (or A-MPDU subframe).

[0106] The sending end can determine which previously transmitted MPDUs need to be retransmitted based on various methods. For example, it can determine this based on the feedback acknowledgment frame sent by the receiving end, or by considering its own service requirements, or by combining the feedback acknowledgment sent by the receiving end with its own actual situation. It should be noted that for cases where it is not necessary to use the feedback acknowledgment frame sent by the receiving end to determine which MPDUs need to be retransmitted, or in other cases, step S102 can be omitted or the receiving end can ignore the feedback acknowledgment frame in step S102. Therefore, it can be understood that step S102 is optional.

[0107] Optionally, an MPDU that needs to be retransmitted can be an MPDU that was not successfully received by the receiver in a previous transmission, while an MPDU that does not need to be retransmitted can be an MPDU that was successfully received by the receiver in a previous transmission or an MPDU that was not correctly received and no longer needs to be retransmitted, such as when the MPDU's expiration time has expired.

[0108] In previous transmissions, at least one prior LDPC codeword obtained after encoding at least one first A-MPDU subframe may include two types: LDPC codewords spanning both ends and LDPC codewords not spanning both ends. At least one first A-MPDU may include LDPC codewords spanning both ends and LDPC codewords not spanning both ends, or one of them. At least one prior LDPC codeword obtained after encoding the first A-MPDU subframe can also be understood as all or part of the information bits contained in all or at least one of the LDPC codewords in the first A-MPDU subframe.

[0109] A portion of the information bits in an LDPC codeword that spans both ends is contained in at least one first A-MPDU subframe (the subframe corresponding to the MPDU that needs to be retransmitted). All bits of the information bits in an LDPC codeword that does not span both ends are contained in at least one first A-MPDU subframe (the subframe corresponding to the MPDU that needs to be retransmitted). An LDPC codeword that spans both ends can be understood as a codeword in which only a portion of the information bits are contained in the A-MPDU subframe of the MPDU that needs to be retransmitted or in the A-MPDU subframes of consecutive MPDUs to be retransmitted. An LDPC codeword that does not span both ends can be understood as a codeword in which all the information bits are contained in the A-MPDU subframe of the MPDU that needs to be retransmitted or in the A-MPDU subframes of consecutive MPDUs to be retransmitted.

[0110] In one example, at least one pre-transmitted LDPC codeword includes: a first LDPC codeword, which is an LDPC codeword spanning both ends, wherein the information bits of the first LDPC codeword correspond to a first set of information bits included in at least one first A-MPDU subframe, and a second set of information bits not included in at least one first A-MPDU subframe. In this embodiment, since the information bits are encoded first and then scrambled, the information bits of the first LDPC codeword include: a first set of information bits and a second set of information bits. In one example, the second set of information bits may be the second set of information bits in a correctly received second A-MPDU subframe adjacent to at least one first A-MPDU subframe.

[0111] Depending on the number of MPDUs that need to be retransmitted and their location, the MPDUs that need to be retransmitted include, but are not limited to, the following situations or combinations thereof:

[0112] The first scenario: There is only one MPDU that needs to be retransmitted, namely the first MPDU.

[0113] In the previous transmission, a first A-MDPU subframe, after LDPC encoding, includes at least one pre-transmitted LDPC codeword, including a first LDPC codeword (an LDPC codeword spanning both ends). The information bits of the first LDPC codeword are included in a first set of information bits in the first A-MPDU subframe, and a second set of information bits not included in the first A-MPDU subframe. In the A-MPDU, this second set of information bits may be adjacent to the first set of information bits, and is included in a second A-MPDU subframe adjacent to the first A-MPDU subframe, where the MPDU of the second A-MPDU subframe is correctly received. For example... Figure 5a As shown, if the MPDU to be retransmitted is MPDU2 included in A-MPDU subframe 2, then the first LDPC codeword includes LDPC codewords 3 and 5; if the MPDU to be retransmitted is MPUD5 in A-MPDU subframe 5, then the first LDPC codeword includes codewords 9 and 11.

[0114] The second scenario is that the MPDU that needs to be retransmitted includes at least two MPDUs, and in the previous transmission of A-MPDUs, the A-MPDU subframes corresponding to these at least two MPDUs are not adjacent to each other.

[0115] For example, the MPDUs that need to be retransmitted include a first MPDU and a second MPDU. In the previous transmission, the A-MPDU, the first MPDU, and the second MPDU corresponded to non-adjacent first A-MPDU subframes and second A-MPDU subframes, respectively. In the previous transmission, the first A-MPDU subframe, after LDPC encoding, included a first LDPC codeword 1, and the second A-MPDU subframe, after LDPC encoding, included a first LDPC codeword 2. The information bits of the first LDPC codeword 1 are included in the first information bit set 1 of the first A-MPDU subframe and are not included in the second information bit set 1 of the first A-MPDU subframe. The information bits of the first LDPC codeword 2 are included in the first information bit set 2 of the second A-MPDU subframe and are not included in the second information bit set 2 of the second A-MPDU subframe. For example... Figure 5a As shown, if the MPDUs that need to be retransmitted are MPDU2 in A-MPDU subframe 2 and MPDU5 in A-MPDU subframe 5, then the first LDPC codeword 1 includes LDPC codewords 3 and 5, and the first LDPC codeword 2 includes LDPC codeword 9.

[0116] The third scenario: The MPDU that needs to be retransmitted includes at least two MPDUs, and in the previous transmission of A-MPDUs, the A-MPDU subframes corresponding to these at least two MPDUs that need to be retransmitted are adjacent, that is, the at least two MPDUs are consecutive. The first LDPC codeword is the codeword that spans at least two adjacent A-MPDU subframes.

[0117] For example, the MPDU to be retransmitted includes multiple MPDUs corresponding to multiple adjacent A-MPDU subframes. The first MPDU and the second MPDU, in the previously transmitted A-MPDUs, correspond to the first and second A-MPDU subframes, respectively, with the first A-MPDU subframe being the first among the adjacent A-MPDU subframes and the second A-MPDU subframe being the last among the adjacent A-MPDU subframes. In the previous transmission, the multiple adjacent A-MPDU subframes, after LDPC encoding, include a first LDPC codeword 1 and a first LDPC codeword 2. The first LDPC codeword 1 and the first LDPC codeword 2 are the LDPC codewords corresponding to the information bits at the beginning and end of these multiple adjacent subframes. The information bits of the first LDPC codeword 1 are included in the first information bit set 1 of the first A-MPDU subframe and are not included in the second information bit set 1 of the first A-MPDU subframe. The information bits of the first LDPC codeword 2 are included in the first information bit set 2 of the second A-MPDU subframe, and are not included in the second information bit set 2 of the second A-MPDU subframe. For example Figure 5aAs shown, if the MPDUs that need to be retransmitted include MPDU2 in A-MPDU subframe 2, MPDU3 in A-MPDU subframe 3, and MDPU4 in A-MPDU subframe 4, then the first LDPC codeword 1 is LDPC codeword 3, and the first LDPC codeword 2 is codeword 9.

[0118] The consecutive MPDUs to be retransmitted are those that have adjacent MPDUs or adjacent sequence numbers in the previously transmitted A-MPDUs (either one is acceptable, and the first type will be used as an example below). For example, if the previously transmitted A-MPDUs include MPDU 1, MPDU 2, MPDU 4 and MPDU 5, and MPDU 2 and MPDU 4 are incorrect, while the other MPDUs are received correctly, then MPDU 2 and MPDU 4 can be called the MPDUs to be retransmitted consecutively.

[0119] The fourth scenario: The MPDUs that need to be retransmitted include at least three MPDUs, and in the previous transmission of A-MPDUs, the A-MPDU subframes corresponding to at least two of the MPDUs that need to be retransmitted are adjacent, and the A-MPDU subframe corresponding to at least one MPDU that needs to be retransmitted is not adjacent to other A-MPDU subframes. It is understandable that the first LDPC codeword in the fourth scenario can be considered a combination of the first and third scenarios, or a combination of the second and third scenarios; this will not be elaborated further here.

[0120] In one example, the first MPDU that needs to be retransmitted may be an MPDU that was not successfully received by the receiver. In this case, the information bits of the first LDPC codeword are contained in the first information bit set (not successfully received) and the second information bit set in the first A-MPDU subframe. Optionally, the second information bit set may be the information bits from an MPDU that was successfully received by the receiver. For example... Figure 5a As shown, assuming the transmitter determines that MPDU2 in A-MPDU subframe 2 was not successfully received by the receiver, and MPDU3 in A-MPDU subframe 3 was successfully received, then the first LDPC codewords are LDPC codeword 3 and LDPC codeword 5.

[0121] S104: Transmit at least one retransmitted LDPC codeword encoded in at least one first A-MPDU subframe. The at least one retransmitted LDPC codeword includes punctured codewords, where the punctured codewords are all or part of the encoded bits of the second information bit set in the second LDPC codeword after puncturing. The second LDPC codeword is determined based on the information bits of the first LDPC codeword. The at least one retransmitted LDPC codeword encoded in the first A-MPDU subframe can be understood as all or part of the information bits contained in all or at least one of the LDPC codewords of the first A-MPDU subframe.

[0122] In step S104, the transmitting end retransmits the first MPDUs that need to be retransmitted as determined in step S103. The multiple first MPDUs that need to be retransmitted can be sequentially encapsulated into multiple consecutive first A-MPDU subframes according to their previous transmission order, and then encoded into at least one retransmitted LDPC codeword. Optionally, the at least one retransmitted LDPC codeword further includes at least one unpunctured codeword, where all information bits of the at least one unpunctured codeword are contained within the at least one first A-MPDU subframe.

[0123] "Punching" can be understood as "deleting," and the bits in a "punched" codeword can be understood as the bits in a "deleted" codeword. It should be noted that not all retransmitted LDPC codewords contain a second information bit set; only LDPC codewords that span both ends contain a second information bit set, and only then does the second information bit set need to be punched.

[0124] For the different scenarios included in the first LDPC codeword, we will explain the different scenarios for the information bits in the punched second LDPC.

[0125] In the second scenario: the MPDU to be retransmitted includes at least two MPDUs, and in the previously transmitted A-MPDUs, the A-MPDU subframes corresponding to these at least two MPDUs are not adjacent to each other. During retransmission, these at least two MPDUs are constructed into adjacent A-MPDU subframes, i.e., contained within at least two adjacent A-MPDU subframes, and in the same order as in the initial transmission. The transmitting end generates a second LDPC codeword based on the information bits of the first LDPC codeword, and there is a certain correspondence between the positions of the first LDPC codeword and the second LDPC codeword. The transmitting end can puncture the second information bit set of all or part of the second LDPC codewords; for example, only the first and last two second LDPC codewords among multiple second LDPC codewords can be punctured, while the middle part of the second LDPC codewords can be punctured or not. For example, as... Figure 5c As shown, the previously transmitted MPDU2 and MPDU4 need to be retransmitted. One implementation method is as follows: Figure 5c Punch holes in LDPC codeword 3 and LDPC codeword 9, but not in LDPC codewords 5 and LDPC codeword 7. This method reduces the receiving complexity at the receiver. Another approach ( Figure 5c (Not shown), LDPC codewords 3, 9, 5, and 7 are all punctured. Using this method, information bits that do not need to be retransmitted can be punctured, thus effectively reducing retransmission overhead.

[0126] For the third scenario, for example, Figure 5bAs shown, the previously transmitted MPDU2 and MPDU3 need to be retransmitted. The retransmitted codewords include the second LDPC codewords, which are LDPC codewords 3 and LDPC codewords 7. The second information bit set 1 (bits corresponding to the gray area) of LDPC codeword 3 is punctured, and the second information bit set 2 (bits corresponding to the gray area) of LDPC codeword 7 is punctured.

[0127] In the fourth scenario, similar to the second scenario, the second LDPC codeword in the middle section can be either punched or not. Further details will not be provided here.

[0128] In S104, the sending end obtains the second LDPC codeword based on the information bits of the previously transmitted first LDPC codeword. Methods for obtaining the second LDPC codeword include, but are not limited to, the following implementations.

[0129] The first method involves the sending end using a chase-and-merge CC method to obtain the second LDPC codeword.

[0130] Implementation method 1: The sending end obtains the first LDPC codeword previously transmitted and uses it as the second LDPC codeword.

[0131] In other words, the sending end stores at least one previously transmitted LDPC codeword. The sending end obtains at least one previously transmitted previously transmitted codeword as at least one retransmission codeword. Specifically, the first LDPC codeword is directly used as the second LDPC codeword (but the information bits that have been correctly received need to be punctured), and other previously transmitted codewords other than the first LDPC codeword are used as other retransmission codewords other than the second LDPC codeword, without needing to re-encode at least one first A-MPDU subframe, thus reducing the complexity and latency of the sending end. The situation corresponding to the first LDPC codeword has been described in detail in step S103, and will not be repeated here.

[0132] Implementation Method 2: The transmitting end uses retransmission coding parameters to encode the information bits of the first LDPC codeword to obtain the second LDPC codeword (but it is necessary to punch holes in the information bits that have been correctly received); the retransmission coding parameters are the same as the coding parameters used for the first LDPC codeword. Optionally, the coding parameters include LDPC code length and code rate. Of course, other retransmission coding parameters can also be used to obtain retransmission LDPC codewords. One set of code length and code rate coding parameters corresponds to one LDPC parity check matrix.

[0133] The second method: The sending end can use IR to obtain the second LDPC codeword.

[0134] Implementation Method 3: Use a retransmission check matrix to encode the information bits of the first LDPC codeword to obtain the second LDPC codeword (but it is necessary to punch holes in the information bits that have been correctly received); the first LDPC and the second LDPC codeword are both generated based on the same LDPC check matrix, but they transmit different parts of the encoded bits generated by the LDPC check matrix, and the different parts can overlap; of course, similar methods can also be used to obtain other LDPC retransmission codewords.

[0135] Implementation Method 4: Retransmissions and previous transmissions generate LDPC codes based on different parity-check matrices. The parity-check matrices used in retransmissions and previous transmissions have a predefined relationship; that is, the retransmission parity-check matrix is ​​expanded by adding rows and columns to the previously transmitted parity-check matrix. The LDPC codewords generated based on the retransmission parity-check matrix include the previously transmitted LDPC codewords. Therefore, during retransmission, the previously transmitted LDPC codewords can be removed from the newly generated LDPC codewords. A similar method can also be used to obtain other LDPC retransmission codewords.

[0136] In implementations three and four, new check bits are generated from the information bits contained in at least one prior LDPC codeword corresponding to the MPDU to be retransmitted or consecutive MPDUs to be retransmitted, and combined with the corresponding information bits to form at least one new retransmitted LDPC codeword. Generally, the set of information bits (including the number of bits and their corresponding values) contained in at least one retransmitted LDPC codeword is the same as the set of information bits contained in at least one previously transmitted prior LDPC codeword. In other words, the previously transmitted and retransmitted LDPC codewords are generated using the same parent LDPC codebook, meaning the information bits contained in the previously transmitted and retransmitted LDPC codewords are the same, and the check bits are different subsets of the check bits in the parent LDPC codeword. These different subsets can overlap. Optionally, the information bits (information bits that were not correctly received) contained in at least one retransmitted LDPC codeword may also be partially or completely punctured, depending on the codebook design in the HARQ IR; this application does not impose any restrictions.

[0137] It is worth noting that the above implementation methods one to four take the generation of the second LDPC codeword by the first LDPC as an example, but they are also applicable to the generation of retransmitted LDPC codewords by other LDPC codewords to be retransmitted besides the first LDPC codeword, and will not be elaborated here.

[0138] In one example, in step S104, the at least one first MPDU retransmitted by the sending end can also be encapsulated together with at least one second MPDU transmitted initially into a single physical layer protocol data unit (PLAN) and sent out. The at least one second MPDU transmitted initially in this A-MPDU can be encoded using the same encoding parameters. Optionally, the at least one MPDU transmitted initially can be encoded with different encoding parameters than the at least one first MPDU retransmitted, or they can be encoded with the same encoding parameters.

[0139] Figure 5b An example of retransmission MPDU2 and MPDU3 according to an embodiment of this application is shown. Figure 5a An example of a previously transmitted A-MPDU is shown. In step S101, the sending end sends to the receiving end... Figure 5a The A-MPDU shown includes A-MPDU subframes 1 to 5. Optionally, in step S102, the sending end receives an acknowledgment from the receiving end. In step S103, the sending end determines that the MPDUs that need to be retransmitted are MPDU2 in A-MPDU subframe 2 and MPDU3 in A-MPDU subframe 3. In step S104, as... Figure 5b As shown, the transmitting end retransmits MPDU2 and MPDU3. The transmitting end determines the second LDPC codeword as LDPC codeword 3 and LDPC codeword 5, and then transfers the information bits in LDPC codeword 3 ( Figure 5b Punch holes in the dark-medium region 1) and remove the information bits from LDPC codeword 5. Figure 5b 2) Punch holes in the dark area of ​​the image. Optionally, the sender also sends A-MPDU subframe 6 and A-MPDU subframe 7, which can be the data transmitted in the first transmission.

[0140] Optionally, sending at least one retransmitted LDPC codeword further includes: scrambling the at least one retransmitted LDPC codeword, and sending the scrambled at least one retransmitted LDPC codeword. Optionally, since the scrambling operation occurs after encoding, different scrambling sequences can be used for scrambling in each A-MPDU transmission.

[0141] The provisions mentioned in this embodiment are applicable to other embodiments unless otherwise specified in other embodiments.

[0142] The method in this application embodiment ensures that the information bits corresponding to the retransmitted LDPC codeword are the same as those corresponding to the previously transmitted LDPC codeword, and the corresponding check bits are also the same. This allows the receiving end to directly merge and decode or jointly decode the LLR of the retransmitted LDPC codeword and the LLR of the previously transmitted LDPC codeword, reducing the complexity of the receiving end, saving decoding time, and improving transmission efficiency. Furthermore, the method in this application embodiment can be applied to scenarios involving the aggregation of multiple MPDUs, realizing MPDU retransmission based on the A-MPDU structure, supporting retransmission in WLANs, and further improving the stability of the WLAN system.

[0143] Example 2 describes in detail a method for receiving retransmitted data, based on the aforementioned first process (i.e., the transmitting end encodes and then scrambles the MAC layer frame, and correspondingly, the receiving end descrambles and then decodes the PHY layer data unit), to improve the transmission reliability and efficiency of the wireless communication system. Example 2 corresponds to Example 1.

[0144] Figure 6 This illustration shows a flowchart of a method for receiving retransmitted data according to an embodiment of this application. The method includes:

[0145] S201: Receive Aggregated Media Intervention Control Protocol Data Unit (A-MPDU), where the A-MPDU includes at least one A-MPDU subframe, and the at least one A-MPDU subframe includes a first A-MPDU subframe, and the first A-MPDU subframe includes a first MPDU.

[0146] Correspondingly, the receiving end performs constellation demapping, descrambling, and decoding on the received physical layer protocol data unit to parse and obtain the A-MPDU. For a detailed introduction to the A-MPDU, please refer to step S101 in the aforementioned embodiment, which will not be repeated here.

[0147] S202: The receiving end confirms at least one first MPDU that needs to be retransmitted in the previously transmitted A-MPDU, the first MPDU being contained in the first A-MPDU subframe of the A-MPDU.

[0148] There are several methods for the receiving end to determine the MPDUs that need to be retransmitted. In one implementation, the receiving end can determine at least one first MPDU that needs to be retransmitted based on the MPDUs that were not successfully received in step S202. In this case, step S202 can be placed before step S203. In another implementation, the receiving end can determine at least one first MPDU that needs to be retransmitted based on the MPDU re-indication information carried in the PPDU received in step S204.

[0149] Optionally, S203: The receiving end sends an acknowledgment feedback frame, wherein the acknowledgment feedback is used to indicate which MPDUs in the A-MPDU were not successfully received.

[0150] Optionally, in S202, the receiving end acknowledges that at least one first MPDU transmission failed. The receiving end identifies the MPDU that was not successfully received in the A-MPDU and provides acknowledgment feedback for the received MPDU, including not replying, replying using NACK, ACK, BlockACK, and Multi-STA Block Ack, etc., the specific information of which has been described in detail in step S102.

[0151] S204: Receive at least one retransmitted LDPC codeword after encoding at least one first A-MPDU subframe, wherein the at least one retransmitted LDPC codeword includes a punctured codeword, wherein the punctured codeword is all or part of the encoded bits of the second information bit set in the second LDPC codeword after puncturing, and the second LDPC codeword is determined based on the information bits of the first LDPC codeword.

[0152] It should be noted that the receiving end receives a PPDU carrying a retransmitted MPDU, which includes at least one first MPDU from at least one first A-MPDU subframe, and this first MPDU is a retransmitted MPDU. Optionally, the PPDU may also include other non-retransmitted MPDUs, such as the MPDU transmitted initially.

[0153] In the previous transmission, at least one first-transmitted LDPC codeword obtained after encoding at least one first A-MPDU subframe may include two types: LDPC codewords that span both ends and LDPC codewords that do not span both ends, or of course, only LDPC codewords that span both ends.

[0154] A portion of the information bits of an LDPC codeword that spans both ends is included in at least one first A-MPDU subframe (the subframe corresponding to the MPDU that needs to be retransmitted). All bits of the information bits of an LDPC codeword that does not span both ends are included in at least one first A-MPDU subframe (the subframe corresponding to the MPDU that needs to be retransmitted). An LDPC codeword that spans both ends can be referred to as a codeword that spans both ends of the MPDU that needs to be retransmitted or a series of MPDUs to be retransmitted. An LDPC codeword that does not span both ends can be referred to as a codeword that is included at both ends of the MPDU that needs to be retransmitted or a series of MPDUs to be retransmitted.

[0155] The information bits of the first LDPC codeword are included in a first set of information bits in at least one first A-MPDU subframe, and are not included in a second set of information bits in at least one first A-MPDU subframe. In one example, the second set of information bits may be the second set of information bits in a second A-MPDU subframe that was not successfully received and is adjacent to the first A-MPDU subframe.

[0156] S205: Combine and decode or jointly decode the at least one retransmitted LDPC codeword and the at least one previously received pretransmitted LDPC codeword to obtain the first A-MPDU subframe.

[0157] It should be noted that decoding and encoding are corresponding operations. Therefore, the encoding parameters and decoding parameters for the same information should be matched or correspond to each other.

[0158] The at least one retransmitted LDPC codeword further includes: at least one unpunctured codeword, wherein all information bits of the at least one unpunctured codeword are contained within the at least one first A-MPDU subframe to be retransmitted. The at least one unpunctured codeword is an LDPC codeword that does not span the beginning and end of a frame.

[0159] For punctured codewords, before merging or joint decoding: the transmitting end needs to pad the second information bit set to the punctured codeword to obtain the second LDPC codeword; for unpunctured codewords, padding is not required. Further, retransmission decoding parameters are used to decode at least one retransmitted LDPC codeword and the previously received at least one pre-transmitted LDPC codeword to obtain at least one first A-MPDU subframe; wherein, the retransmission decoding parameters are the same as the decoding parameters used to decode the previously transmitted first LDPC codeword. It should be noted that the decoded information bits include a second information bit set not included in at least one first A-MPDU subframe; therefore, after decoding, the second information bit set needs to be deleted to obtain at least one first A-MPDU subframe, thereby achieving the retransmission of at least one first MPDU.

[0160] Optionally, if the at least one retransmitted LDPC codeword sent by the transmitter is a scrambled LDPC codeword, then the receiver may also descramble the at least one retransmitted LDPC codeword before decoding to obtain the descrambled LDPC codeword. Since the scrambling operation occurs after encoding, different scrambling sequences can be used for scrambling in each A-MPDU transmission.

[0161] For HARQ CC, the receiver combines and decodes the LLR of the LDPC codeword of the retransmitted first MPDU with the LLR of the LDPC codeword of the previously received first MPDU. For HARQ IR, the receiver performs joint decoding on the LLR of the LDPC codeword of the retransmitted MPDU with the LLR of the LDPC codeword of the previously erroneously received MPDU.

[0162] Optionally, the method further includes: providing acknowledgment feedback for each MPDU in the A-MPDU of the PPDU. The acknowledgment feedback method includes no response, NACK, ACK, Block ACK, and Multi-STA Block Ack, etc. For details, please refer to step S102, which will not be repeated here.

[0163] The provisions mentioned in this embodiment are applicable to other embodiments unless otherwise specified in other embodiments.

[0164] The method in this application embodiment ensures that the information bits corresponding to the retransmitted LDPC codeword are the same as those corresponding to the previously transmitted LDPC codeword, and the corresponding check bits are also the same. The receiving end can directly merge and decode or jointly decode the LLR of the retransmitted LDPC codeword and the LLR of the previously transmitted LDPC codeword, reducing the complexity of the receiving end, saving decoding time, and improving transmission efficiency. Furthermore, the method in this application embodiment can be applied to scenarios involving the aggregation of multiple MPDUs, realizing MPDU retransmission based on the A-MPDU structure, supporting retransmission in WLAN, and further improving the stability of the WLAN system.

[0165] Example 3 describes in detail the second process described above (i.e., the transmitting end scrambles the MAC layer frame first and then encodes it, and correspondingly, the receiving end decodes the PHY layer data unit first and then descrambles it), providing a method for transmitting retransmitted data to improve the transmission reliability and efficiency of the wireless communication system.

[0166] Figure 6 This illustration shows a flowchart of a method for receiving retransmitted data according to an embodiment of this application. The method includes:

[0167] Step S301: Send the Aggregated Media Intervention Control Protocol Data Unit (A-MPDU), which includes at least one A-MPDU subframe; optionally, the A-MPDU may also include other A-MPDU subframes.

[0168] The difference between step S301 and step S101 is that after the A-MPDU is assembled at the MAC layer, it is passed to the PHY layer. At the PHY layer, the transmitter first scrambles the A-MPDU and then performs LDPC encoding. Optionally, after obtaining the LDPC codeword, constellation point mapping and other operations are performed, and then a physical layer preamble (the physical layer preamble typically includes a Non-HT, non-highthroughput (traditional) preamble and a next-generation physical layer preamble) is added to form a PPDU, which is then transmitted via the transmitter's antenna.

[0169] In step S301, the scrambling operation at the transmitting end occurs before encoding. Optionally, the period of the scrambling sequence can be 127 bits. For example, a 127-bit sequence is 00001110 11110010 11001001 00000010 0010011000101110 10110110 00001100 11010100 11100111 10110100 00101010 1111101001010001 10111000 1111111. One method of scrambling is as follows: The information bits of the A-MPDU, from the first bit to the last bit, are XORed with a scrambling sequence with a period of 127 bits. For example, if the A-MPDU contains 200 information bits, the first 127 information bits of the A-MPDU are XORed with a 127-bit scrambling sequence, and then the last 73 information bits of the A-MPDU are XORed with the first 73 bits of the 127-bit scrambling sequence to obtain the scrambled bit sequence. For ease of description, the scrambling sequence used in step S301 to scramble the A-MPDU can be called the pre-transmission scrambling sequence, and the encoding parameters used in step S301 to encode the A-MPDU can be called the pre-transmission encoding parameters.

[0170] like Figure 8a As shown: The A-MPDU sent in step S301 includes: A-MPDU subframes 1 to 5, wherein the A-MPDU is scrambled and encoded sequentially using a pre-transmitted scrambling sequence and pre-transmitted encoding parameters to obtain LDPC codewords 1 to LDPC codewords 10.

[0171] Step S302: Receive acknowledgment feedback information, wherein the acknowledgment feedback information is used to indicate which MPDUs in the A-MPDU failed to be received. Step S302 is similar to step S102, and will not be described again here.

[0172] Optionally, in step S302, the acknowledgment feedback information sent by the receiving end indicates that at least one first MPDU was not successfully received.

[0173] Step S303: Determine at least one first MPDU in the previously transmitted Aggregated Media Intervention Control Protocol Data Unit (A-MPDU) that needs to be retransmitted.

[0174] At least one first MPDU that needs to be retransmitted is contained in at least one first A-MPDU subframe of the previously transmitted A-MPDU. The various methods by which the sender determines which previously transmitted MPDUs need to be retransmitted are similar to those in step S103, and will not be repeated here.

[0175] The previously transmitted A-MPDU (or A-MPDU subframe) refers to the A-MPDU (or A-MPDU subframe) transmitted before step S303, i.e., the A-MPDU (or A-MPDU subframe) transmitted in step S301. The A-MPDU (or A-MPDU subframe) transmitted in step S301 can be the A-MPDU (or A-MPDU subframe) of the previous transmission retransmitted in S303, or it can be the A-MPDU (or A-MPDU subframe) of the first transmission. This application embodiment is not limited. For ease of description, the A-MPDU (or A-MPDU subframe) transmitted in step S301 is referred to here as the previously transmitted A-MPDU (or A-MPDU subframe). It should be noted that step S303 is similar to step S103, the difference being that in step S303, at least one previously transmitted first A-MPDU subframe is first scrambled and then encoded into at least one pre-transmitted LDPC codeword. Therefore, in this embodiment (Embodiment 3), the LDPC codeword obtained by scrambling and then encoding the at least one first A-MPDU subframe transmitted previously is at least one previously transmitted LDPC codeword, and the LDPC codeword obtained by scrambling and then encoding the first information bit set and the second information bit set transmitted previously is the first LDPC codeword.

[0176] In the previous transmission, at least one first-transmitted LDPC codeword obtained by scrambling and then encoding at least one first A-MPDU subframe may include two types: LDPC codewords that span both ends and LDPC codewords that do not span both ends, and of course, it may only include LDPC codewords that span both ends.

[0177] A portion of the information bits of an LDPC codeword that spans both ends is included in the scrambled bits of the at least one first A-MPDU subframe (the subframe corresponding to the MPDU to be retransmitted). All bits of the information bits of an LDPC codeword that does not span both ends are included in the scrambled bits of the at least one first A-MPDU subframe (the subframe corresponding to the MPDU to be retransmitted). An LDPC codeword that spans both ends is a codeword that spans both ends of the MPDU to be retransmitted or consecutive MPDUs to be retransmitted. An LDPC codeword that does not span both ends is a codeword that is included both ends of the MPDU to be retransmitted or consecutive MPDUs to be retransmitted.

[0178] At least one pre-transmitted LDPC codeword includes a first LDPC codeword, which is an LDPC codeword spanning both ends. Unlike step S103, the information bits of the first LDPC codeword are information bits scrambled using a scrambling sequence on both the first and second information bit sets. The first information bit set is included in the first A-MPDU subframe, while the second information bit set is not included in the first A-MPDU subframe.

[0179] Similar to step S103, in one example, the second information bit set can be the second information bit set in a second A-MPDU subframe that is adjacent to the first A-MPDU subframe and does not need to be retransmitted. Optionally, if the first MPDU that needs to be retransmitted was not successfully received, and the MPDU that does not need to be retransmitted was successfully received, then the first information bit set consists of the bits that were not successfully received, and the second information bit set consists of the bits that were successfully received.

[0180] The description of the first LDPC codeword varies depending on the number of MPDUs that need to be retransmitted and the location of the MPDUs that need to be retransmitted, and will not be repeated here.

[0181] S304: Send at least one retransmitted LDPC codeword after scrambling and encoding at least one first A-MPDU subframe, wherein the at least one retransmitted LDPC codeword includes a punctured codeword, the punctured codeword being all or part of the coded bits of the scrambled second information bit set in the second LDPC codeword after puncturing, and the second LDPC codeword being determined based on the information bits of the first LDPC codeword.

[0182] In step S304, the transmitting end retransmits the first MPDUs that need to be retransmitted as determined in step S303. Multiple first MPDUs that need to be retransmitted can be arranged sequentially into multiple consecutive first A-MPDU subframes according to their previous transmission order, and then scrambled and encoded into at least one retransmitted LDPC codeword. Optionally, the at least one retransmitted LDPC codeword further includes at least one unpunctured codeword, where all information bits in the at least one unpunctured codeword are contained within the scrambled bits of the at least one A-MPDU subframe. The unpunctured codeword is an LDPC codeword whose beginning and end do not span across the entire frame. "Punching" can be understood as "deleting," and the bits in the "punctured" codeword can be understood as the bits in the "deleted" codeword. It is understood that not all retransmitted LDPC codewords contain the scrambled second information bit set; only LDPC codewords whose beginning and end span across the entire frame require puncturing the scrambled second information bit set.

[0183] In S304, the transmitting end obtains the second LDPC codeword based on the information bits of the previously transmitted first LDPC codeword. Methods for obtaining the second LDPC codeword include, but are not limited to, the following implementations:

[0184] For methods using CC, including:

[0185] Implementation method 1: The sending end obtains the first LDPC codeword previously transmitted and uses it as the second LDPC codeword.

[0186] In other words, the sending end stores at least one previously transmitted LDPC codeword. The sending end obtains at least one previously transmitted previously transmitted codeword as at least one retransmitted codeword. Specifically, the first LDPC codeword is directly used as the second LDPC codeword, and other previously transmitted codewords besides the first LDPC codeword are used as other retransmitted codewords besides the second LDPC codeword, without needing to re-encode at least one first A-MPDU subframe, thus reducing the complexity and latency of the sending end. The situation corresponding to the first LDPC codeword has been described in detail in step S103, and will not be repeated here.

[0187] Implementation Method 2: The transmitting end uses retransmission coding parameters to encode the information bits of the first LDPC codeword to obtain the second LDPC codeword; the retransmission coding parameters are the same as the pre-transmission coding parameters used for the first LDPC codeword. Optionally, the coding parameters include LDPC code length and code rate. Alternatively, retransmission coding parameters can be used to obtain other LDPC retransmission codewords. In another implementation method, the first and second information bit sets corresponding to the first LDPC codeword can be directly scrambled and then encoded to obtain the second LDPC codeword. It is understood that other retransmission codewords can also be obtained in a similar way, which will not be elaborated further. Optionally, the coding parameters include one or more of the following combinations: code length, code rate, parity check matrix, generator matrix, etc. A pair of code rate and code length parameters corresponds to a parity check matrix or a generator matrix.

[0188] Implementation methods using IR include:

[0189] Implementation Method 3: A retransmission check matrix is ​​used to encode the information bits of the first LDPC codeword to obtain the second LDPC codeword. Both the first and second LDPC codewords are generated based on the same LDPC check matrix, but different portions of the encoded bits generated by that LDPC check matrix are transmitted, and these different portions can overlap. Alternatively, a retransmission check matrix can be used to obtain other retransmission LDPC codewords.

[0190] Implementation Method 4: Retransmission and Previous Transmission Based on Different Parity-Check Matrices to Generate LDPC Codes. The parity-check matrices used in retransmission and previous transmission have a predefined relationship; that is, the retransmission parity-check matrix is ​​expanded by adding rows and columns to the previously transmitted parity-check matrix. The LDPC codewords generated based on the retransmission parity-check matrix include the previously transmitted LDPC codewords. Therefore, during retransmission, the previously transmitted LDPC codewords can be removed from the newly generated LDPC codewords. A similar method can also be used to obtain other retransmission LDPC codewords.

[0191] In implementations three and four, new check bits are generated from the information bits contained in at least one prior LDPC codeword corresponding to the MPDU to be retransmitted or consecutive MPDUs to be retransmitted, and combined with the corresponding information bits to form at least one new retransmitted LDPC codeword. Generally, the set of information bits (including the number of bits and their corresponding values) contained in at least one retransmitted LDPC codeword is the same as the set of information bits contained in at least one previously transmitted prior LDPC codeword. In other words, the previously transmitted and retransmitted LDPC codewords are generated using the same parent LDPC codebook, meaning the information bits contained in the previously transmitted and retransmitted LDPC codewords are the same, and the check bits are different subsets of the check bits in the parent LDPC codeword. Optionally, different subsets can overlap. Optionally, the scrambled information bits to be retransmitted contained in at least one retransmitted LDPC codeword may also be partially or completely punctured, depending on the codebook design in the HARQ IR; this application does not impose any restrictions.

[0192] It is worth noting that the above implementation methods one to four take the generation of the second LDPC codeword by the first LDPC as an example, but they are also applicable to the generation of retransmitted LDPC codewords by other LDPC codewords to be retransmitted besides the first LDPC codeword, and will not be elaborated here.

[0193] In one example, in step S304, at least one first MPDU retransmitted by the sending end can also be encapsulated together with at least one second MPDU transmitted initially into a physical layer protocol data unit and sent out.

[0194] The encoding methods for retransmission, previous transmission, and first transmission can include, but are not limited to, the following:

[0195] The first encoding method: The retransmitted MPDU uses the same scrambling sequence and encoding parameters as the previously transmitted MPDU. In one example, at least one second MPDU transmitted for the first time in S304 can be encoded with the same encoding parameters as the retransmitted MPDU, and scrambled using a periodic scrambling sequence generated by the same scrambling seed. In another example, at least one second MPDU transmitted for the first time can be encoded with different encoding parameters than at least one first MPDU transmitted for the retransmitted MPDU, or they can be encoded with the same encoding parameters. The at least one second MPDU transmitted for the first time can optionally be scrambled with different periodic scrambling sequences (i.e., corresponding to different scrambling seeds) than at least one first MPDU transmitted for the retransmitted MPDU, or they can be scrambled with the same periodic scrambling sequence.

[0196] The second encoding method involves retransmitting the MPDU with a different scrambling sequence than the previously transmitted MPDU, while using the same encoding parameters. In one example, the retransmitted MPDU uses the same periodic scrambling sequence as the first transmitted MPDU. In this case, the sender needs to inform the receiver of the scrambling seed (corresponding to the periodic scrambling sequence) used in the A-MPDU subframe containing the retransmitted MPDU. This scrambling seed can be indicated by the physical layer preamble of the PPDU, including using several bits of a random field of the physical layer preamble, such as cyclic redundancy check (CRC), but it must also ensure that the scrambling seed is not all zeros, for example, fixing 1 bit as 1; or the receiver can be informed of the scrambling seed through a mutually agreed-upon method, such as using the scrambling seed function from the previous transmission, like adding 1.

[0197] Figure 8b An example of retransmitting MPDU2 and MPDU3 is shown. Figure 8a An example of a previously transmitted A-MPDU is shown. In step S301, the sending end sends to the receiving end... Figure 8a The A-MPDU shown above includes A-MPDU subframes 1 to 5, which are scrambled and encoded before being transmitted. Optionally, in step S302, the receiving end sends an acknowledgment feedback message indicating that MPDU2 and MPDU3 were not successfully received. In step S303, the sending end determines that the MPDUs that need to be retransmitted are MPDU2 in A-MPDU subframe 2 and MPDU3 in A-MPDU subframe 3. In step S304, as... Figure 8bAs shown, the transmitting end retransmits MPDU2 and MPDU3. The transmitting end determines LDPC codewords 3 and LDPC codeword 5 as the second LDPC codeword (LDPC codewords that span both ends), and then scrambles the bits in LDPC codeword 3 ( Figure 8b Punch holes in the darker areas of the medium and remove the scrambled bits from LDPC codeword 5. Figure 8b The area shown in the dashed line is punched. Optionally, the transmitter also transmits A-MPDU subframes 6 and 7, which include the first transmitted MPDU. Multiple MPDUs initially transmitted in this A-MPDU (e.g., MPDU6 in A-MPDU subframe 6 and MPDU7 in A-MPDU subframe 7) can be scrambled using a periodic scrambler sequence generated from the same scrambler seed. This scrambler seed can be generated randomly or according to a specific rule. Understandably, the multiple MPDUs initially transmitted can be scrambled with retransmitted MPDUs using different periodic scrambling sequences (i.e., corresponding to different scrambler seeds).

[0198] Figure 8c An example of retransmitting MPDU2 and MPDU4 is shown. In step S304, as follows: Figure 8b As shown, the transmitting end retransmits MPDU2 and MPDU4, determines the second LDPC codeword as LDPC codeword 3 and LDPC codeword 9, and converts the scrambled bits in LDPC codeword 3 ( Figure 8c Punch holes in the darker areas of the medium and remove the scrambled bits from LDPC codeword 9. Figure 8c Punching (in the darker areas). For information bits in LDPC codewords 5 and 7, puncturing is optional. Punching removes information bits that don't need retransmission (bits that have been correctly received), effectively reducing retransmission overhead; not punching reduces the receiver's complexity.

[0199] The provisions mentioned in this embodiment are applicable to other embodiments unless otherwise specified in other embodiments.

[0200] The method in this embodiment ensures that the information bits corresponding to the retransmitted LDPC codeword are the same as those corresponding to the previously transmitted LDPC codeword, and the corresponding check bits are also the same. This allows the receiving end to directly merge and decode or jointly decode the LLR of the retransmitted LDPC codeword and the LLR of the previously transmitted LDPC codeword, reducing the complexity of the receiving end, saving decoding time, and improving transmission efficiency. Furthermore, this embodiment can scramble the retransmitted MDDU before encoding it without changing the existing processing flow, improving compatibility and reducing the complexity of retransmission at the sending end. The method in this embodiment can be applied to scenarios involving the aggregation of multiple MPDUs, realizing MPDU retransmission based on the A-MPDU structure, supporting retransmission in WLAN, and further improving the stability of the WLAN system.

[0201] Example 4 describes in detail the second scenario mentioned above (i.e., the transmitting end scrambles the MAC layer frame first and then encodes it, and correspondingly, the receiving end decodes the PHY layer data unit first and then descrambles it), providing a method for receiving retransmitted data to improve the transmission reliability and efficiency of the wireless communication system.

[0202] Figure 9 This illustration shows a flowchart of a method for receiving retransmitted data according to an embodiment of this application. The method includes:

[0203] S401: Receive Aggregated Media Access Control Protocol Data Unit (A-MPDU); the A-MPDU includes at least one A-MPDU subframe. Optionally, the A-MPDU may also include other A-MPDU subframes.

[0204] Correspondingly, optionally, the receiving end performs constellation demapping, decoding, descrambling, and other processing on the received physical layer protocol data unit to parse it and obtain the A-MPDU. For a detailed introduction to the A-MPDU, please refer to the aforementioned embodiments; it will not be repeated here.

[0205] S402: Determine at least one first MPDU that needs to be retransmitted from the previously transmitted A-MPDU, the at least one first MPDU being contained in at least one first A-MPDU subframe.

[0206] Step S402 can be referred to step S202, and will not be repeated here.

[0207] The difference is that the first A-MPDU subframe, after scrambling and coding, includes at least one pre-transmitted LDPC codeword, wherein the at least one pre-transmitted LDPC codeword includes the first LDPC codeword, and the information bits of the first LDPC codeword include the first information bit set in the first A-MPDU subframe and the scrambled bits of the second information bit set not included in the first A-MPDU subframe.

[0208] S403: Send an acknowledgment feedback frame, where the acknowledgment feedback is used to indicate which MPDUs in the A-MPDU were not successfully received.

[0209] The receiving end identifies MPDUs that were not successfully received in the A-MPDU and provides acknowledgment feedback for the received MPDUs, including no reply, replying using NACK, ACK, Block ACK, and Multi-STA Block Ack, as detailed in step S102. Optionally, the receiving end reports that at least one first MPDU was not successfully received, and at least one first MPDU corresponds to at least one first A-MPDU subframe.

[0210] S404: Receive at least one retransmitted LDPC codeword after scrambling and encoding at least one first A-MPDU subframe sent by the transmitting end, wherein the at least one retransmitted LDPC codeword includes a punctured codeword, wherein the punctured codeword is all or part of the encoded bits of the scrambled second information bit set in the second LDPC codeword after puncturing, and the second LDPC codeword is determined based on the information bits of the first LDPC codeword.

[0211] It should be noted that the receiving end receives the PPDU carrying the retransmitted MPDU; this PPDU includes the first MPDU in the first A-MPDU subframe, and this first MPDU is a retransmitted MPDU. Optionally, the PPDU may also include other non-retransmitted MPDUs, such as the MPDU from the initial transmission.

[0212] In the previous transmission, at least one first-transmitted LDPC codeword obtained by scrambling and then encoding at least one first A-MPDU subframe may include two types: LDPC codewords that span both ends and LDPC codewords that do not span both ends, and of course, it may only include LDPC codewords that span both ends.

[0213] A portion of the information bits of an LDPC codeword that spans both ends is included in the scrambled bits of the at least one first A-MPDU subframe (the subframe corresponding to the MPDU to be retransmitted). All bits of the information bits of an LDPC codeword that does not span both ends are included in the scrambled bits of the at least one first A-MPDU subframe (the subframe corresponding to the MPDU to be retransmitted). An LDPC codeword that spans both ends is a codeword that spans both ends of the MPDU to be retransmitted or consecutive MPDUs to be retransmitted. An LDPC codeword that does not span both ends is a codeword that is included both ends of the MPDU to be retransmitted or consecutive MPDUs to be retransmitted.

[0214] At least one prior LDPC codeword includes a first LDPC codeword, which is an LDPC codeword that spans both ends. Optionally, at least one prior LDPC codeword may also include an LDPC codeword that does not span both ends.

[0215] The number and position of the MPDUs to be retransmitted vary, and the first LDPC codeword also varies. For a detailed description of the first LDPC codeword, please refer to the aforementioned Embodiment 3, which will not be repeated here.

[0216] S405: Combine and decode or jointly decode the at least one retransmitted LDPC codeword and the at least one previously received pretransmitted LDPC codeword to obtain the first A-MPDU subframe.

[0217] It should be noted that decoding and encoding are corresponding operations, so the encoding parameters and decoding parameters for the same information should be matched or corresponding.

[0218] The at least one retransmitted LDPC codeword further includes: at least one unpunctured codeword, wherein all information bits of the at least one unpunctured codeword are contained in the scrambled bits of the at least one first A-MPDU subframe, and the at least one unpunctured codeword is an LDPC codeword that does not span the beginning and end.

[0219] For punctured codewords, before merging and decoding, the transmitting end needs to pad the scrambled second information bit set to the punctured codeword to obtain the second LDPC codeword; for unpunctured codewords, padding is not required.

[0220] Furthermore, using retransmission decoding parameters, at least one retransmitted LDPC codeword and the previously received at least one prior LDPC codeword are decoded to obtain scrambled information bits. Further, using a retransmission scrambling sequence, the scrambled information bits are descrambled to obtain a first A-MPDU subframe. It should be noted that the descrambled information bits include a second set of information bits not included in at least one first A-MPDU subframe. Therefore, after descrambling, the second set of information bits needs to be deleted to obtain at least one first A-MPDU subframe, thereby achieving successful retransmission of at least one first MPDU.

[0221] For the transmitting end, the first encoding method is used, meaning the retransmitted MPDU uses the same scrambling sequence and encoding parameters as the previously transmitted MPDU. This corresponds to the first decoding method at the receiving end. The receiving end uses the same retransmission scrambling sequence and decoding parameters as the previously transmitted MPDU during decoding. It's understandable that the decoding parameters and encoding parameters are corresponding.

[0222] For the second encoding method used by the transmitter, where the scrambling sequence used in the retransmitted MPDU differs from that used in the previously transmitted MPDU (the retransmitted scrambling sequence is a new one, while the previously transmitted one is the old one), and the same encoding parameters are used, this corresponds to the second decoding method used by the receiver. In this case, the transmitter needs to inform the receiver of the new scrambling seed (corresponding to a periodic scrambling sequence) used in the A-MPDU subframe containing the retransmitted MPDU. This new scrambling seed can be indicated by the physical layer preamble of the PPDU, including using several bits of a random field of the physical layer preamble, such as Cyclic Redundancy Check (CRC), but it must also satisfy that the scrambling seed is not all 0s, for example, fixing 1 bit as 1; or the receiver can be informed of the new scrambling seed through a mutually agreed-upon method, such as using the function of the previously transmitted old scrambling seed, such as adding 1.

[0223] Optionally, in the second decoding method, the receiving end needs to compare the bits encoded by the retransmitted MPDU scrambled with the new scrambling sequence with the bits encoded by the previously transmitted MPDU scrambled with the old scrambling sequence. If the nth bit is the same, the LLR of the nth bit of the previously transmitted MPDU remains unchanged. If the nth bit is different, the LLR of the previously transmitted MPDU is multiplied by -1, where n = 1…N, and N is the code length. Then, the LLR of the retransmitted MPDU's encoded bits is combined with or jointly decoded with the LLR of the previously transmitted MPDU. Finally, the decoded bits are descrambled, and the descrambling scrambler seed is the new scrambler seed of the retransmitted MPDU. Alternatively, this method can be used without adjusting the sign of the LLR of the previously transmitted MPDU's encoded bits, but instead adjusting the sign of the LLR of the retransmitted MPDU's encoded bits. In this case, the scrambler seed used for descrambling is the old scrambler seed used in the previously transmitted MPDU.

[0224] For HARQ CC, the receiver combines and decodes the LLR of the LDPC codeword of the retransmitted first MPDU with the LLR of the LDPC codeword of the previously received first MPDU. For HARQ IR, the receiver performs joint decoding on the LLR of the LDPC codeword of the retransmitted MPDU with the LLR of the LDPC codeword of the previously erroneously received MPDU.

[0225] Optionally, the method further includes: providing acknowledgment feedback for each MPDU in the A-MPDU of the PPDU. The acknowledgment feedback method includes no response, NACK, ACK, Block ACK, and Multi-STA Block Ack, etc. For details, please refer to step S102, which will not be repeated here.

[0226] The provisions mentioned in this embodiment are applicable to other embodiments unless otherwise specified in other embodiments.

[0227] The method in this embodiment ensures that the information bits corresponding to the retransmitted LDPC codeword are the same as those corresponding to the previously transmitted LDPC codeword, and the corresponding check bits are also the same. This allows the receiving end to directly merge and decode or jointly decode the LLR of the retransmitted LDPC codeword and the LLR of the previously transmitted LDPC codeword, reducing the complexity of the receiving end, saving decoding time, and improving transmission efficiency. Furthermore, this embodiment can scramble the retransmitted MDDU before encoding it without changing the existing processing flow, improving compatibility and reducing the complexity of retransmission at the sending end. The method in this embodiment can be applied to scenarios involving the aggregation of multiple MPDUs, realizing MPDU retransmission based on the A-MPDU structure, supporting retransmission in WLAN, and further improving the stability of the WLAN system.

[0228] Example 5 provides a method for transmitting Physical Layer Protocol Data Unit (PPDU).

[0229] Figure 10 This application illustrates a method for transmitting physical layer protocol data units, applied at a transmitting end, comprising:

[0230] S501: Generate an aggregated media access control protocol data unit (A-MPDU), wherein the A-MPDU includes at least one first A-MPDU subframe and at least one second A-MPDU subframe; the first A-MPDU subframe includes a first type media access control protocol data unit (MPDU); and the second A-MPDU subframe includes a second type MPDU.

[0231] The total length of at least one first A-MPDU subframe is a first length L1; the total length of at least one second A-MPDU subframe is a second length L2, and the total length of the A-MPDU subframes is a third length L3; wherein, the third length L3 refers to the length of all A-MPDU subframes. The third length L3 can also be denoted as APEP_LENGTH (in the 802.11ac and 802.11ax protocols). In the HT PPDU defined in the 802.11n standard, the third length L3 can be indicated by the length in the HT-SIG A field.

[0232] In the embodiments of this application, at least one first A-MPDU subframe is adjacent in the A-MPDU, that is, it includes at least one first type MPDU, and at least one second A-MPDU subframe is also adjacent in the A-MPDU, that is, it includes at least one second type MPDU.

[0233] In one example, the first type of MPDU and the second type of MPDU can be two service types with different priorities, and these two types of MPDUs need to be encoded using different encoding parameters. In another example, the two types of MPDUs can be two service types with different reliability requirements, and also need to be encoded using different encoding parameters. In yet another example, the two types of MPDUs can be retransmitted and non-retransmitted data, and the encoding parameters used are also different.

[0234] In the following description, this application uses the first type of MPDU as a retransmitted MPDU and the second type of MPDU as a non-retransmitted MPDU as examples. It is understood that this scheme is also applicable to other situations, and this application is not limited thereto. It should be noted that the MPDU requiring retransmission can be an MPDU that was not successfully received in a previous transmission, used for HARQ transmission. The receiving end will perform LLR merging and decoding or joint decoding on the retransmitted MPDU and the corresponding previously failed MPDU. The non-retransmitted MPDU can be an MPDU that was successfully received in a previous transmission, and also includes retransmitted MPDUs used for ARQ transmission. Although these MPDUs are retransmitted, the receiving end does not need to perform corresponding HARQ reception processing on the retransmitted MPDUs. How to determine which MPDUs need to be retransmitted can be referred to the previous embodiments, and will not be repeated here.

[0235] In the transmission preceding step S501, the transmitting end also sends at least one first A-MPDU subframe. A first A-MPDU includes a first type MPDU, where the encoding parameters used in the first A-MPDU subframe are called pre-transmission encoding parameters, including bit rate and code length. The bits after encoding and other operations, along with the bits after encoding and other operations of the other A-MPDU subframes, are encapsulated into a PPDU. This PPDU, to distinguish it from those in step S502, is called a pre-transmission PPDU.

[0236] It is worth noting that in actual products, for the same bitrate, only one parity check matrix is ​​specified for the code length combination, so the parity check matrix is ​​not mentioned in the encoding parameters here. However, in academic theory, for the same bitrate, different parity check matrices can be used for the code length combination, so the parity check matrix needs to be considered in this case.

[0237] S502: Determine the first coding parameters based on the coding parameters of the first A-MPDU subframe previously transmitted, and determine the second coding parameters based on the second length L2;

[0238] The encoding parameters of the first A-MPDU subframe can also be determined in other ways, and this invention does not impose any restrictions.

[0239] S503: Using the first encoding parameter and the second encoding parameter respectively, encapsulate at least one first A-MPDU subframe and at least one second A-MPDU subframe into the data field of a physical layer protocol data unit (PPDU);

[0240] The data field of the PPDU includes a first part encoded using a first encoding parameter to at least one first A-MPDU subframe, and a second part encoded using a second encoding parameter to at least one second A-MPDU subframe. The first part includes N1 OFDM symbols, and the second part includes N2 OFDM symbols. For example, Figure 11 A schematic diagram of a PPDU is shown, which includes a preamble and a data field, and optionally a packet extension (PE) field. The preamble field may also include a traditional preamble and a next-generation preamble.

[0241] S504: Send the PPDU.

[0242] The first encoding parameter is the encoding parameter for encapsulating at least the first A-MPDU subframe, and the second encoding parameter is the encoding parameter for encapsulating at least the second A-MPDU subframe.

[0243] In 802.11n, the LDPC code length used by each MPDU in an A-MPDU is determined by the length field in HT-SIGA (high-throughput signaling field A). This length field indicates the length of the PSDU. When the PPDU carries the A-MPDU, the PSDU length is the A-MPDU Pre-EOF Padding length (as mentioned above). In 802.11ac / ax, the LDPC code length used by each MPDU in an A-MPDU is determined by the length of the A-MPDU Pre-EOF Padding, denoted as APEP_LENGTH. (802.11ac is used as an example.)

[0244] In this embodiment, since there are retransmitted MPDUs and the first transmitted MPDU, it is necessary to determine the second encoding parameter based on the second length L2, that is, to determine the LDPC code length used in the first transmitted MPDU. The retransmitted MPDU needs to refer to the encoding parameters used when the MPDU was previously transmitted.

[0245] In one example, the first encoding parameter includes the encoding code length and encoding code rate, which are the same as the encoding code length and encoding code rate of the at least one previously transmitted first A-MPDU subframe; in another example, the first encoding parameter includes a parity check matrix, which has a preset relationship with the parity check matrix of the at least one previously transmitted first A-MPDU subframe.

[0246] Determining the second coding parameters based on the second length L2 includes: determining the number N2 of OFDM symbols corresponding to the at least one second A-MPDU subframe based on the second length L2; and determining the number N of coding bits required for the at least one second A-MPDU subframe based on the number N2 of OFDM symbols. avbit Based on N avbit Determine the second encoding parameter.

[0247] In one implementation of this application, the sending end can calculate N based on the following formula. avbit :

[0248]

[0249] N avbit =N2·N CBPS (Formula 2)

[0250] When the data uses the STBC method, m STBC =2, otherwise m STBC =1; N DBPS The number of information bits that each OFDM symbol can carry; N service N represents the length of the service field in the PPDU structure. CBPS The number of coded bits that each OFDM symbol can carry. N service The length of the service field in the PPDU structure is currently 16 bits, but it may increase, decrease, or even decrease to 0 in the future.

[0251] It should be understood that, in the actual implementation process, the sending end calculates N2 and N. avbit There are several ways to do this. For example, you can directly substitute (Formula 1) into (Formula 2) to get N. avbit N can also be calculated based on other equivalent variations or simplifications of (Formula 1) and (Formula 2). avbit It can also store L2 and N calculated based on (Formula 1) and (Formula 2). avbit A mapping table of parameters is used to determine N by looking up the table. avbitFurthermore, in the 802.11ax protocol, due to the introduction of packet extension, some of the final coded bits do not necessarily occupy a complete OFDM symbol; they can be 1 / 4, 1 / 2, 3 / 4, or 1 of the number of coded bits carried by a single OFDM symbol. The total number of coded bits N avbit =(N2-m STBC )·N CBPS +m STBC ·N CBPS,last , where N CBPS,last This refers to the number of coded bits contained in the last OFDM symbol. This application does not specifically limit the embodiments. Furthermore, the transmitting end can determine L2 based on the first length L1 and the third length L3, or directly from the length of at least one second A-MPDU subframe, or through other methods.

[0252] Further optional, based on N avbit Determining the second encoding parameter includes: determining the encoding code length included in the second encoding parameter based on a preset correspondence between encoded bits and code lengths. In one example, the preset correspondence between encoded bits and code lengths is shown in Table 1 below, based on N... avbit Refer to the table below to obtain the LDPC code length for at least one second A-MPDU subframe in this encoding process. The code rate can depend on channel conditions; alternatively, a higher coding rate can be used under the same channel conditions.

[0253] Table 1

[0254]

[0255] Where N pld =8×APEP_LENGTH+N service R represents the LDPC code rate, currently used in WiFi at 1 / 2, 2 / 3, 3 / 4, and 5 / 6 code rates. APEP_LENGTH is the A-MPDU Pre-EOF Padding length, in bytes.

[0256] In this embodiment, optionally, the PPDU preamble includes a length indicator, which indicates either the first length L1 or the second length L2, allowing the receiver to determine decoding parameters based on the second length L2. In a first implementation, the length indicator indicates the first length L1. The receiver can determine L2 based on the length indicator, for example, L2 = L3 - L1. In a second implementation, the length indicator directly indicates the second length, allowing the receiver to directly obtain the second length L2.

[0257] In the third implementation, the preamble of the PPDU includes information indicating the first decoding parameters of the first part and / or the second decoding parameters of the second part, including code length, code rate, etc. The receiver directly determines the first and second decoding parameters to be used based on this information in the PPDU.

[0258] The three implementation methods described above all employ a method of carrying a display indication in the physical layer preamble. In the fourth implementation, the length can be indicated by the receiver itself, not the transmitter. Instead, the receiver feeds back the length information to the PHY layer through its MAC layer, allowing the PHY layer to know the total length L1 of the erroneously received A-MPDU subframes in the previous transmission. Specifically, the receiving MAC layer searches the first 4 bytes of each A-MPDU subframe using a 4-byte sliding window to obtain the total length of the erroneously received A-MPDU subframes (the MPDU delimiter is 4 bytes and contains MPDU length indication information; the A-MPDU subframe length is also an integer multiple of 4 bytes). If the entire A-MPDU is incorrect, the receiver can then calculate the total length of all A-MPDU subframes, i.e., the A-MPDU Pre-EOF Padding length, using the length field of the L-SIG field in the traditional preamble (Non-HT preamble) and the fixed length of the PPDU preamble.

[0259] For the third length L3 of all A-MPDU subframes, i.e. the A-MPDU Pre-EOF Padding length, the receiver can deduce it from the length field of the L-SIG field of the traditional preamble (Non-HT preamble) and the length of the PPDU preamble.

[0260] The above method does not consider scrambling operation. If the scrambling operation at the transmitting end is before the encoding operation, the A-MPDU construction method may also include that the periodic scrambling sequence used in the first A-MPDU (including retransmitted MPDU) and the second A-MPDU (including new transmitted MPDU) subframes is different.

[0261] The first A-MPDU subframe uses the same scrambling sequence as the previous or first transmission of the first A-MPDU subframe, i.e., the same periodic scrambling sequence (depending on the scrambling seed). The first bit or nth bit of the scrambling sequence for the first A-MPDU (including retransmitted MPDUs) is the same as the first bit or nth bit of the same scrambling sequence used in the previous or first transmission of the A-MPDU subframe containing the MPDU. The second A-MPDU subframe corresponding to the newly transmitted MPDU is scrambled using a different new periodic scrambling sequence. For example, the scrambling seed is generated using the existing 802.11ac / ax method, and the scrambling device is the same as that used in 802.11ac / ax, generating a periodic 127-bit sequence.

[0262] The provisions mentioned in this embodiment are applicable to other embodiments unless otherwise specified in other embodiments.

[0263] This application proposes a method for constructing an MPDU that includes a retransmission MPDU and an initial transmission MPDU. This method is applied to scenarios where multiple MPDUs are aggregated, and realizes MPDU retransmission based on the A-MPDU structure. This enables retransmission in WLAN and further improves the stability of the WLAN system.

[0264] Example 6 corresponds to Example 5 and is a method for the receiving end.

[0265] Figure 12 This application illustrates a method for receiving a PPDU, applied at a receiving end, comprising:

[0266] S601: Receive a Physical Layer Protocol Data Unit (PPDU), wherein the data field of the PPDU includes a first part encoded by at least one first A-MPDU subframe using a first encoding parameter, and a second part encoded by at least one second A-MPDU subframe using a second encoding parameter; a first A-MPDU subframe includes a first type MPDU, and a second A-MPDU subframe includes a second type MPDU.

[0267] Wherein, the total length of the at least one first A-MPDU subframe is a first length L1; the total length of the at least one second A-MPDU subframe is a second length L2; and the total length of the A-MPDU subframe is a third length L3. The first part includes N1 OFDM symbols, and the second part includes N2 OFDM symbols.

[0268] The descriptions of the first type of MPDU and the second type of MPDU can be found in the aforementioned embodiment S501, and will not be repeated here. Similarly, this embodiment also uses the first type of MPDU as a retransmitted MPDU and the second type of MPDU as a non-retransmitted MPDU as an example. The MPDU that needs to be retransmitted can be an MPDU that was not successfully received in the previous transmission and is used for HARQ transmission. The receiving end will perform LLR merging and decoding or joint decoding on the retransmitted MPDU and the corresponding failed MPDU from the previous transmission. The non-retransmitted MPDU (or the initial transmission MPDU) can be an MPDU that was successfully received in the previous transmission, and also includes retransmitted MPDUs used for ARQ transmission. Although the MPDU is retransmitted, the receiving end does not need to perform corresponding HARQ reception processing on the retransmitted MPDU. How to determine which MPDUs need to be retransmitted can be found in the previous embodiments, and will not be repeated here.

[0269] In the transmission prior to step S601, the receiving end also receives at least one of the first A-MPDU subframes. A first A-MPDU includes a first type MPDU, wherein the first A-MPDU subframe is encoded using pre-transmission encoding parameters to encapsulate it into a PPDU. This PPDU is distinguished from the one in step S601 and is called a pre-transmission PPDU.

[0270] S602: Decode the PPDU using the first encoding parameter and the second encoding parameter respectively to obtain the at least first A-MPDU subframe and the at least one second A-MPDU subframe;

[0271] The first encoding parameter is determined based on the pre-transmitted encoding parameters of the previously transmitted first A-MPDU subframe, but it can also be determined in other ways; this invention is not limited to these methods. The second encoding parameter is determined based on the second length L2. It should be noted that the first encoding parameter actually corresponds to the first decoding parameter, and the second encoding parameter actually corresponds to the second decoding parameter. The first decoding parameter is used to decode the first part of the PPDU data field, and the second decoding parameter is used to decode the second part of the PPDU data field.

[0272] The first decoding parameters (corresponding to the first encoding parameters) include the encoding code length and encoding code rate, which are the same as the code length and code rate of the at least one previously transmitted first A-MPDU subframe; or,

[0273] The first decoding parameter (corresponding to the first encoding parameter) includes a check matrix, which has a preset relationship with the check matrix of the at least one previously transmitted first A-MPDU subframe.

[0274] Optionally, the receiving end can also determine the second decoding parameters (corresponding to the second encoding parameters) based on the second length L2, specifically including:

[0275] The number of OFDM symbols N2 corresponding to the at least one second A-MPDU subframe is determined based on the second length L2;

[0276] The number of coding bits N required for the at least one second A-MPDU subframe is determined based on the number of OFDM symbols N2. avbit ;

[0277] Based on N avbit Determine the second decoding parameter.

[0278] In one implementation of this application, the receiving end can calculate N based on the following formula. avbit :

[0279]

[0280] N avbit =N2·N CBPS (Formula 2)

[0281] When the STBC method is used, m STBC =2, otherwise m STBC =1; N DBPS The number of information bits that each OFDM symbol can carry; N service N represents the length of the service field in the PPDU structure. CBPS The number of coded bits that each OFDM symbol can carry. N service The length of the service field in the PPDU structure is currently 16 bits, but it may increase, decrease, or even decrease to 0 in the future.

[0282] It should be understood that, in the actual implementation process, the receiving end calculates N2 and N. avbit There are several ways to do this. For example, you can directly substitute (Formula 1) into (Formula 2) to get N. avbit N can also be calculated based on other equivalent variations or simplifications of (Formula 1) and (Formula 2). avbit It can also store L2 and N calculated based on (Formula 1) and (Formula 2). avbit A mapping table of parameters is used to determine N by looking up the table. avbit Furthermore, in the 802.11ax protocol, due to the introduction of packet extension, some of the final coded bits do not necessarily occupy a complete OFDM symbol; they can be 1 / 4, 1 / 2, 3 / 4, or 1 of the number of coded bits carried by a single OFDM symbol. The total number of coded bits N avbit =(N2-m STBC)·N CBPS +m STBC ·N CBPS,last , where N CBPS,last The number of coded bits contained in the last OFDM symbol is not specifically limited in the embodiments of this application. Furthermore, the receiving end can determine L2 based on the first length L1 and the third length L3, or it can directly determine L2 from the length of at least one second A-MPDU subframe, or it can determine L2 through other means.

[0283] Further optional, based on N avbit Determining the second decoding parameters includes: determining the encoded code length included in the second encoding parameters according to a preset correspondence between encoded bits and code lengths. In one example, the preset correspondence between encoded bits and code lengths is shown in Table 1. The receiving end can also look up the table to determine the second decoding parameters (corresponding to the second encoding parameters). Table 1 can be found in Embodiment 5, and will not be repeated here.

[0284] The above method does not consider scrambler operation. If the descrambling operation at the receiving end is after the decoding operation, the A-MPDU construction method may also include that the periodic scrambling sequence used in the first A-MPDU (including retransmitted MPDU) and the second A-MPDU (including new transmitted MPDU) subframes is different.

[0285] The first A-MPDU subframe uses the same scrambling sequence as the previous or first transmission of the first A-MPDU subframe, i.e., the same periodic scrambling sequence (depending on the scrambling seed). The first bit or nth bit of the scrambling sequence for the first A-MPDU (including retransmitted MPDUs) is the same as the first bit or nth bit of the same scrambling sequence used in the previous or first transmission of the A-MPDU subframe containing the MPDU. The second A-MPDU subframe corresponding to the newly transmitted MPDU is scrambled using a different new periodic scrambling sequence. For example, the scrambling seed is generated using the existing 802.11ac / ax method, and the scrambling device is the same as that used in 802.11ac / ax, generating a periodic 127-bit sequence.

[0286] The receiving end uses the scrambling code sequence of the last transmission of the first A-MPDU or the first transmission of the first A-MPDU to descramble the received first A-MPDU subframe, and uses a new periodic scrambling code sequence to descramble the second A-MPDU subframe, such as using an existing descrambling method, that is, obtaining the seed from the received scrambled service field for descrambling.

[0287] In this embodiment, the receiving end can determine the L2 length based on the information carried in the PPDU preamble, thereby determining the decoding parameters. Alternatively, it can directly determine the decoding parameters based on the L-SIG in the PPDU and its own internal processing. Specific details can be found in the description of the aforementioned Embodiment 5, and will not be repeated here.

[0288] The provisions mentioned in this embodiment are applicable to other embodiments unless otherwise specified in other embodiments.

[0289] This application proposes a method for constructing an MPDU that includes a retransmission MPDU and an initial transmission MPDU. This method is applied to scenarios where multiple MPDUs are aggregated, and realizes MPDU retransmission based on the A-MPDU structure. This enables retransmission in WLAN and further improves the stability of the WLAN system.

[0290] Example 7 provides a retransmission indication method. The method includes: transmitting a Physical Layer Protocol Data Unit (PPDU), the PPDU including a Physical Layer preamble and a data field, the data field including an A-MPDU, the A-MPDU including at least one retransmitted MPDU, and / or at least one non-retransmitted MPDU, the Physical Layer preamble including various retransmission indication information. Correspondingly, a receiving end receives the PPDU and parses the PPDU based on the various retransmission indication information.

[0291] Optionally, the PPDU preamble includes an MPDU retransmission indicator, used to indicate whether the PPDU includes a retransmitted MPDU. Here, there can be one or more retransmitted MPDUs. For example, if the MPDU retransmission indicator takes a first value, it indicates that the PPDU includes a retransmitted MPDU; if the MPDU retransmission indicator takes a second value, it indicates that the PPDU does not include a retransmitted MPDU. The MPDU that needs to be retransmitted can be an MPDU that was not successfully received in a previous transmission, used for HARQ transmission. The receiving end will perform LLR merging and decoding or joint decoding on the retransmitted MPDU and the corresponding previously failed MPDU. The non-retransmitted MPDU (or initial transmission MPDU) can be an MPDU that was successfully received in a previous transmission, and also includes retransmitted MPDUs used for ARQ transmission. Although this MPDU is retransmitted, the receiving end does not need to perform corresponding HARQ reception processing on the retransmitted MPDU. Optionally, the receiving end that receives the retransmission instruction can determine whether it is necessary to perform HARQ LLR merging or joint decoding on the retransmitted MPDU in this PPDU and the corresponding MPDU previously received in error.

[0292] Optionally, the PPDU preamble includes a modulation and coding scheme indicator, which is a special value used to indicate that the PPDU contains only retransmitted MPDUs. Here, the retransmitted MPDU can be one or more. If the A-MPDU contains MPDUs that are all retransmitted MPDUs, this can be indicated by using a special modulation and coding scheme in the physical layer preamble. This special modulation and coding scheme indicator takes a special value, such as an unused or undefined value. Currently, in 802.11ax, the modulation and coding scheme is represented by 4 bits. Modulation and coding schemes 0-11 are currently used, while schemes 12-15 are unused. Therefore, this special value can be 12-15.

[0293] Optionally, the preamble of the PPDU includes: a retransmission MPDU length indicator, used to indicate the total length of the A-MPDU subframes containing the retransmission MPDUs included in the PPDU; the total length is in bytes, or the degree indicates the total duration of the A-MPDU subframes containing the retransmission MPDUs.

[0294] Optionally, the PPDU preamble includes a scrambler seed indicator, used to indicate the scrambler seed used for scrambling the retransmitted MPDU.

[0295] The A-MPDU subframe corresponding to the retransmitted MPDU needs to be placed at a preset position in the A-MPDU, such as the start position, middle position, or end position. Since an A-MPDU may contain one or more management frames, control frames, and data frames, if only data frames support HARQ transmission, then the retransmitted MPDU only needs to be placed at the preset position of all data frames or before all other A-MPDU subframes, such as the start position, middle position, or end position. The preset position can be specified by the protocol, designated by the AP, or determined through negotiation between the AP and STA. Another implementation method places the A-MPDU subframe corresponding to the retransmitted MPDU after the existing PPDU preamble and before the service field. Note: The existing PPDU contains the physical layer preamble, service field, and A-MPDU in that order, and optionally also includes physical layer padding bits and packet extension.

[0296] It should be noted that the solution in Embodiment 7 can be used as a standalone embodiment, or it can be applied to the solutions in Embodiments 1 to 6 above, or it can be combined with other implementation schemes.

[0297] This application proposes a retransmission indication method that can be applied to scenarios where multiple MPDUs are aggregated. It realizes MPDU retransmission based on the A-MPDU structure, enabling retransmission in WLAN and further improving the stability of the WLAN system.

[0298] Next, in Embodiment 8 of this application, taking the MPDU that needs to be retransmitted as the MPDU that the receiver failed to receive, and using LDPC coding for channel encoding as an example, a method for retransmitting MPDU according to an embodiment of this application will be described. In A-MPDU, an additional MPDU delimiter and possible padding bytes are required before the MPDU is sent to form an A-MPDU subframe. For simplicity, the MPDU and its corresponding A-MPDU subframe will not be distinguished below, and they can be understood as the same.

[0299] The first process involves channel coding of the A-MPDU at the transmitting end, followed by scrambling:

[0300] 1. First, channel coding is performed on the A-MPDU, and then scrambling is applied. Each A-MPDU transmission can use a different scrambling code sequence for scrambling.

[0301] 2. Send the aggregated data packet A-MPDU, where A-MPDU contains one or more MPDUs. The assembly process of A-MPDU occurs at the MAC layer. The A-MPDU is then passed to the PHY physical layer, where it is encoded, scrambled, and subjected to constellation point mapping. A physical layer preamble (typically a Non-HT, non-highthroughput (traditional) preamble or a next-generation physical layer preamble) is then added to form a PPDU, which is then sent out. The PPDU assembly process will not be detailed below. This invention primarily focuses on multiple MPDUs, but is also applicable to the case of a single MPDU. Furthermore, the aggregated data packet sent by the station can be transmitted in single-user (SU) mode or multi-user (MU) mode. Multi-user mode can be further divided into OFDMA transmission, MU-MIMO mode, or a hybrid mode of OFDMA and MU-MIMO.

[0302] 3. The receiving station (STA) sends an acknowledgment feedback, which informs the sending end which MPDUs in the A-MPDU transmitted this time need to be received incorrectly. The sending end combines the acknowledgment feedback frame with its own transmission status to determine which MPDUs to retransmit.

[0303] This invention does not limit the acknowledgment feedback method. A station can use a negative acknowledgment (NACK), a bitmap in a block acknowledgment (Block Ack), or a bitmap in a multi-STA block acknowledgment (Multi-STA Block Ack) to indicate which MPDUs were not received, but whose corresponding traditional preamble was correctly received or whose sender and receiver can identify all MPDUs. In other words, it informs the sender which MPDUs can be retransmitted based on HARQ rules. The NACK can be a single frame or a part of a multi-STA block acknowledgment (Multi-STA Block Ack), unlike the current acknowledgment frames and no-response methods. It informs the sender that all MPDUs sent in this transmission were not correctly received. These MPDUs can be one or more, but their corresponding physical layer preamble was correctly received or whose sender and receiver can identify all MPDUs in this transmission.

[0304] 4. For an MPDU to be retransmitted or a series of MPDUs to be retransmitted, find all the relevant LDPC codewords corresponding to its last transmission, including the LDPC codewords that span the beginning and end of the retransmitted MPDU or the series of retransmitted MPDUs and one or more adjacent correctly received MPDUs. Among them, the series of MPDUs with retransmissions are adjacent MPDUs that were erroneously transmitted in the last A-MPDU transmission or MPDUs with adjacent sequence numbers (choose one, preferably the first type, and the first type will be used as an example below). For example, the last transmitted A-MPDUs include MPDU 1, MPDU 2, MPDU 4 and MPDU 5, and MPDU 2 and MPDU 4 were erroneous, while the other MPDUs were correctly received. In this case, MPDU 2 and MPDU 4 can be called MPDUs to be retransmitted continuously.

[0305] 1) For HARQ CC, punch holes in the LDPC codeword corresponding to the MPDU to be retransmitted or the consecutive MPDUs to be retransmitted, i.e., delete the correctly received information bits. It is worth noting that this invention does not limit how the LDPC codeword corresponding to the MPDU to be retransmitted or the consecutive MPDUs to be retransmitted is obtained. The LDPC codeword can be previously stored, or it can be regenerated by LDPC encoding using the same parameters as the stored erroneous MPDUs.

[0306] 2) For HARQ IR, new check bits are generated from the information bits in the LDPC codeword corresponding to the MPDU to be retransmitted or consecutive MPDUs to be retransmitted, and combined with the corresponding information bits to form a new LDPC codeword. Generally speaking, the set of information bits (including the number of bits and their corresponding values) in the new LDPC codeword is the same as the set of information bits in the LDPC codeword of the previous erroneous transmission. In other words, the initial and retransmitted LDPC codewords are generated using the same parent LDPC codebook, meaning that the initial and retransmitted LDPC codewords contain the same number of information bits, and the check bits are different subsets of the check bits in the parent LDPC codeword (different subsets can overlap).

[0307] The correctly received information bits contained in the new LDPC codeword are punctured. Whether the incorrectly received information bits in the LDPC codeword are partially or completely punctured depends on the codebook design in the HARQ IR, and this invention does not impose limitations. It should be understood that not all LDPC codewords contain correctly received information bits. It can be observed that only LDPC codewords spanning the retransmission MPDU or the consecutive retransmission MPDU and one or more adjacent correctly received MPDUs contain correctly received information bits.

[0308] 5. Scramble the encoded bits of the retransmitted MPDU, perform constellation point mapping, etc., and send it out without changing other baseband and radio frequency operations.

[0309] For example: In the previously transmitted A-MPDU, such as Figure 5a As shown, MPDU 2 and MPDU 3 were transmitted incorrectly. During retransmission, when sending the encoded bits of MPDU 2 and MPDU 3, LDPC codewords 3-7 need to be retransmitted. However, the correctly received information bits in LDPC codeword 3 and LDPC codeword 7 need to be punctured, as shown below. Figure 5b The gray part.

[0310] For example, in the initial A-MPDU transmission, such as Figure 5a As shown, MPDU 2 and MPDU 4 were transmitted incorrectly. During retransmission, when sending the encoded bits of MPDU 2 and MPDU 4, LDPC codewords 3-5 and LDPC codewords 7-9 need to be retransmitted. However, the correctly received information bits in LDPC codewords 3, 5, 7, and 9 need to be punctured, as shown below. Figure 8cThe gray and light gray portions. In another implementation, for the sake of simplicity at the receiving end, it is not necessary to check whether the LDPC encoded bits of each MPDU contain the correct information bits. A simple way is to punch holes only in the correct information bits contained in the LDPC encoded bits of the first and last MPDUs. For example, the correctly received information bits (gray) of LDPC codewords 3 and 9 need to be punched, while the correctly received information bits (light gray) of LDPC codewords 5 and LDPC codewords 7 are not punched.

[0311] To support HARQ transmission, the physical layer preamble of the PPDU needs to include an indication of whether it contains a retransmission MPDU. This retransmission MPDU indication tells the receiver whether HARQ LLR merging or joint decoding is needed for the retransmission MPDU in this PPDU and the corresponding MPDU from the previous erroneous reception.

[0312] If the A-MPDU contains retransmitted MPDUs, a special modulation and coding scheme is needed in the physical layer preamble to indicate that the MPDU is unused. Currently, in 802.11ax, the modulation and coding scheme is represented by 4 bits. Modulation and coding schemes 0-11 are currently in use, while schemes 12-15 are unused.

[0313] For A-MPDUs containing retransmitted MPDUs, the physical layer preamble needs to indicate the total length of the A_MDPU subframe containing the retransmitted MPDU, in bytes, or its duration.

[0314] The retransmitted MPDU needs to be placed at a preset position on the A-MPDU, such as the start position, middle position, or end position. Since an A-MPDU may contain one or more types of frames, including management frames, control frames, and data frames, if only data frames support HARQ transmission, then the retransmitted MPDU only needs to be placed at the preset position on all data frames, such as the start position, middle position, or end position. The preset position can be specified by the protocol, designated by the AP, or determined through negotiation between the AP and STA.

[0315] At the receiving end:

[0316] 1. Perform constellation point demapping, descrambling, and decoding on the received data packets. Other RF and baseband operations not mentioned above remain unchanged. The decoding operation will be discussed in detail below.

[0317] 2. For each MPDU in the A-MPDU of the received PPDU that does not contain retransmission MPDU indication information, provide acknowledgment feedback, including no reply, NACK, ACK, Block ACK, and Multi-STA Block Ack.

[0318] 3. For the A-MPDU in the received PPDU containing retransmission MPDU indication information, the LLR of the LDPC codeword of the retransmission MPDU and the LLR of the LDPC codeword of the previously erroneously received MPDU need to be merged and decoded or jointly decoded.

[0319] For HARQ CC, the site will combine and decode the LLR of the LDPC codeword of the retransmitted MPDU with the LLR of the LDPC codeword of the previously erroneously received MPDU. For HARQ IR, the site will combine and decode the LLR of the LDPC codeword of the retransmitted MPDU with the LLR of the LDPC codeword of the previously erroneously received MPDU.

[0320] For LDPC codewords that span both correct and incorrect MPDUs, the station needs to fill in the correctly received information bits that were punched out by the transmitter in the LDPC before decoding.

[0321] Finally, each MPDU in the A-MPDU of the PPDU is acknowledged, including no response, NACK, ACK, Block ACK, and Multi-STA Block Ack.

[0322] The second process involves the transmitter scrambling the A-MPDU before performing channel coding.

[0323] 1. Maintain the existing order of channel coding and scrambling operations, that is, the transmitter performs scrambling first, and then performs channel coding.

[0324] 2. Send the aggregated data packet A-MPDU, where A-MPDU contains one or more MPDUs. The assembly process of A-MPDU occurs at the MAC layer, and then the A-MPDU is passed to the PHY physical layer. The physical layer performs scrambling, encoding, constellation point mapping, and other operations on the A-MPDU, and then adds physical layer preambles (physical layer preambles typically include Non-HT, non-highthroughput (traditional) preambles and next-generation physical layer preambles) to form PPDUs, which are then sent out. The PPDU assembly process will not be detailed below. This invention mainly focuses on multiple MPDUs, but is also applicable to the case of a single MPDU. In addition, the aggregated data packets sent by the station can be transmitted in single-user (SU) mode or multi-user (MU) mode. The multi-user mode is further divided into OFDMA transmission, MU-MIMO mode, or a hybrid mode of OFDMA and MU-MIMO.

[0325] 3. The receiving station (STA) sends an acknowledgment feedback, which informs the sending end which MPDUs in the A-MPDU transmitted this time need to be received incorrectly. The sending end combines the acknowledgment feedback frame with its own transmission status to determine which MPDUs to retransmit.

[0326] This invention does not limit the acknowledgment feedback method. A station can use a negative acknowledgment (NACK), a bitmap in a block acknowledgment (Block Ack), or a bitmap in a multi-STA block acknowledgment (Multi-STA Block Ack) to indicate which MPDUs were not received, but whose corresponding traditional preamble was correctly received or whose sender and receiver can identify all MPDUs. In other words, it informs the sender which MPDUs can be retransmitted based on HARQ rules. The NACK can be a single frame or a part of a multi-STA block acknowledgment (Multi-STA Block Ack), unlike the current acknowledgment frames and no-response methods. It informs the sender that all MPDUs sent in this transmission were not correctly received. These MPDUs can be one or more, but their corresponding physical layer preamble was correctly received or whose sender and receiver can identify all MPDUs in this transmission.

[0327] 3b. The transmitted A-MPDU is scrambled. The retransmitted MPDU and the newly transmitted MPDU may use different periodic scrambling sequences, that is, different scrambling seed.

[0328] The MPDU to be retransmitted is scrambled using the same scrambling sequence as the MPDU previously transmitted or initially transmitted. That is, the periodic scrambling sequence generated by the same scrambling seed, and the first bit or the nth bit of the scrambling sequence of the retransmitted MPDU are the same as the first bit or the nth bit of the same scrambling sequence used in the MPDU previously transmitted or initially transmitted.

[0329] The newly transmitted MPDU uses a periodic scrambler sequence generated by the same scrambler seed. This scrambler seed can be generated randomly or according to a specific rule.

[0330] 4. For an MPDU to be retransmitted or a series of MPDUs to be retransmitted, find all the relevant LDPC codewords corresponding to its last transmission, including the LDPC codewords that span the beginning and end of the retransmitted MPDU or the series of retransmitted MPDUs and one or more adjacent correctly received MPDUs. Among them, the series of retransmitted MPDUs are adjacent MPDUs that were erroneously transmitted in the last A-MPDU transmission or MPDUs with adjacent sequence numbers (choose one, preferably the first type, and the first type will be used as an example below). For example, the last transmitted A-MPDUs include MPDU 1, MPDU 2, MPDU 4 and MPDU 5, and MPDU 2 and MPDU 4 are erroneous, while the other MPDUs are correctly received. Then, MPDU 2 and MPDU 4 can be called MPDUs to be retransmitted continuously.

[0331] 1) For HARQ CC, the scrambled information bits that have been correctly received in the LDPC codeword corresponding to the MPDU to be retransmitted or the consecutive MPDUs to be retransmitted are punctured, i.e. deleted. It is worth noting that this invention does not limit how the LDPC codeword corresponding to the MPDU to be retransmitted or the consecutive MPDUs to be retransmitted is obtained. The LDPC codeword can be previously stored, or it can be regenerated by LDPC encoding using the same parameters as the stored erroneous MPDU.

[0332] 2) For HARQ IR, new check bits are generated from the scrambled information bits in the LDPC codeword corresponding to the MPDU to be retransmitted or consecutive MPDUs to be retransmitted. These new check bits are then combined with the corresponding scrambled information bits to form a new LDPC codeword. Generally speaking, the set of scrambled information bits (including the number of bits and their corresponding values) in the new LDPC codeword is the same as the set of scrambled information bits in the previously erroneously transmitted LDPC codeword (because the same scrambling sequence as the previously transmitted MPDU is used, ensuring that the set of scrambled information bits is the same). In other words, the initial and retransmitted LDPC codewords are generated using the same parent LDPC codebook, meaning that the scrambled information bits in the initial and retransmitted LDPC codewords are the same, and the check bits are different subsets of the check bits in the parent LDPC codeword (different subsets can overlap).

[0333] The scrambled information bits contained in the new LDPC codeword that have been correctly received are perforated. Whether the scrambled information bits contained in the LDPC that were not correctly received are partially or completely perforated depends on the codebook design in the HARQ IR, and this invention does not impose any limitations.

[0334] Note: Not all LDPC codewords contain the scrambled information bits that are being received. It can be observed that only LDPC codewords spanning the retransmission MPDU or the consecutive retransmission MPDU and one or more adjacent correctly received MPDUs contain the scrambled information bits that have been correctly received.

[0335] 5. Send the codeword for the retransmission MPDU; other baseband and RF operations remain unchanged.

[0336] For example: In the initial A-MPDU transmission, such as Figure 8a As shown, MPDU 2 and MPDU 3 were transmitted incorrectly. During retransmission, when sending the encoded bits of MPDU 2 and MPDU 3, LDPC codewords 3-7 need to be retransmitted. However, the correctly received scrambled information bits of LDPC codeword 3 and the correctly received scrambled information bits of LDPC codeword 7 need to be punctured, as shown below. Figure 8b The gray part.

[0337] For example, in the initial A-MPDU transmission, such as Figure 8a As shown, MPDU 2 and MPDU 4 were transmitted incorrectly. During retransmission, when sending the encoded bits of MPDU 2 and MPDU 4, LDPC codewords 3-5 and LDPC codewords 7-9 need to be retransmitted. However, the correctly received scrambled information bits of LDPC codewords 3, 5, 7, and 9 need to be punctured, as shown below. Figure 8c The gray and light gray portions. In another implementation, for simplicity at the receiving end, it's unnecessary to check whether each MPDU's LDPC encoded bits contain the correct scrambled information bits. A simple approach is to punch holes only in the LDPC encoded bits of the first and last MPDUs containing the correct scrambled information bits. For example, the correctly received scrambled information bits (gray) in LDPC codewords 3 and 9 need to be punched. Figure 8c The gray portion, while the correctly accepted scrambled information bits (light gray) of LDPC codewords 5 and 7 are not punched, such as... Figure 8c The light gray part.

[0338] To support HARQ transmission, the physical layer preamble of the PPDU needs to include an indication of whether it contains a retransmission MPDU. This retransmission MPDU indication tells the receiver whether HARQ LLR merging or joint decoding is needed for the retransmission MPDU in this PPDU and the corresponding MPDU from the previous erroneous reception.

[0339] If the A-MPDU contains retransmitted MPDUs, a special modulation and coding scheme is needed in the physical layer preamble to indicate that the MPDU is unused. Currently, in 802.11ax, the modulation and coding scheme is represented by 4 bits. Modulation and coding schemes 0-11 are currently in use, while schemes 12-15 are unused.

[0340] For A-MPDUs containing retransmitted MPDUs, the physical layer preamble needs to indicate the total length of the A_MDPU subframe containing the retransmitted MPDU, in bytes, or its duration. Alternatively, for all A-MPDUs, the physical layer preamble needs to indicate the total length of the A_MDPU subframe containing the retransmitted MPDU, in bytes, or its duration. When the length or duration is 0, it indicates that the A-MPDU does not contain a retransmitted MPDU.

[0341] The retransmitted MPDU needs to be placed at a preset position on the A-MPDU, such as the start position, middle position, or end position. Since an A-MPDU may contain one or more types of frames, including management frames, control frames, and data frames, if only data frames support HARQ transmission, then the retransmitted MPDU only needs to be placed at the preset position on all data frames, such as the start position, middle position, or end position. The preset position can be specified by the protocol, designated by the AP, or determined through negotiation between the AP and STA.

[0342] At the receiving end:

[0343] 1. Perform constellation point demapping, descrambling, and decoding on the received data packets. Other RF and baseband operations not mentioned above remain unchanged. The decoding operation will be discussed in detail below.

[0344] 2. For each MPDU in the A-MPDU of the received PPDU that does not contain retransmission MPDU indication information, provide acknowledgment feedback, including no reply, NACK, ACK, Block ACK, and Multi-STA Block Ack.

[0345] 3. For the A-MPDU in the received PPDU containing retransmission MPDU indication information, the LLR of the LDPC codeword of the retransmission MPDU and the LLR of the LDPC codeword of the previously erroneously received MPDU need to be merged and decoded or jointly decoded.

[0346] For HARQ CC, the site will combine and decode the LLR of the LDPC codeword of the retransmitted MPDU with the LLR of the LDPC codeword of the previously erroneously received MPDU. For HARQ IR, the site will combine and decode the LLR of the LDPC codeword of the retransmitted MPDU with the LLR of the LDPC codeword of the previously erroneously received MPDU.

[0347] For LDPC codewords that span both correct and incorrect MPDUs, the station needs to fill in the scrambled information bits that have been correctly received within the LDPC and which were punched out by the transmitter before decoding.

[0348] 4. Descramble the decoded scrambled information bits. For retransmitted MPDUs, descramble using the scrambling sequence from the previous or first transmission of the MPDU. For newly transmitted MPDUs, descramble using a different periodic scrambling sequence. The scrambler seed for generating this other periodic scrambling sequence can be indicated by the physical layer preamble, including using several bits of a random field of the physical layer preamble, such as CRC, but the scrambler seed must not be all zeros, for example, one bit can be fixed as 1; alternatively, the scrambler seed can be obtained from the all-zero service field of 802.11a / g / n / ac / ax or the scrambled all-zero service field.

[0349] Finally, each MPDU in the A-MPDU of the PPDU is acknowledged, including no response, NACK, ACK, Block ACK, and Multi-STA Block Ack.

[0350] In this embodiment, the MPDU to be retransmitted can also be scrambled using a different scrambling sequence than the previously transmitted MPDU or the initial MPDU, or in other words, it can use the same periodic scrambling sequence as the newly transmitted MPDU. In this case, the transmitting end needs to inform the receiving end of the scrambling seed (corresponding to the periodic scrambling sequence) used in the A-MPDU containing the retransmitted MPDU. This scrambling seed can be indicated by the physical layer preamble, including using several bits of a random field of the physical layer preamble, such as CRC, but at the same time, the scrambling seed must not be all 0, for example, 1 bit is fixed as 1; or the receiving end can be informed of the scrambling seed through a method agreed upon by both parties, such as the scrambling seed function of the last transmission, such as adding 1.

[0351] The receiving end needs to compare the bits encoded in the retransmitted MPDU scrambled with the new scrambling sequence with the bits encoded in the previous transmission of the same MPDU scrambled with the old scrambling sequence. If the nth bit is the same, the LLR of the nth bit of the previously transmitted MPDU remains unchanged. If the nth bit is different, the LLR of the previously transmitted MPDU's encoded bits is multiplied by -1, where n = 1…N, and N is the code length. Then, the LLR of the retransmitted MPDU's encoded bits is combined with or jointly decoded with the LLR of the previously transmitted MPDU. Finally, the decoded bits are descrambled, and the descrambling scrambler seed is the same as the scrambler seed used in the retransmitted MPDU. Alternatively, this method can be used to adjust the LLR of the retransmitted MPDU's encoded bits instead of adjusting the sign of the LLR of the previously transmitted MPDU; in this case, the scrambler seed used for descrambling is the same as the one used in the previous transmission of the MPDU. The provisions mentioned in this embodiment are applicable to other embodiments unless otherwise specified in other embodiments.

[0352] Figure 13 This is a schematic diagram of a transmitting device provided in an embodiment of this application. The transmitting device can be used in the transmitting end or the chip in the transmitting end of any one of Embodiment 1, Embodiment 3, Embodiment 5 or Embodiment 7. The transmitting device 130 includes a processing module 1301, a transmitting module 1302, and a receiving module 1303.

[0353] In one embodiment, the transmitting device can be used to perform any function of the transmitting end in the aforementioned embodiment one, for example:

[0354] Processing module 1301 is configured to determine at least one first MPDU that needs to be retransmitted in a previously transmitted A-MPDU, wherein the at least one first MPDU is contained in at least one first A-MPDU subframe, and the first A-MPDU subframe is encoded to include at least one pre-transmitted LDPC codeword, wherein the at least one pre-transmitted LDPC codeword includes a first LDPC codeword, and the information bits of the first LDPC codeword include a first set of information bits in the first A-MPDU subframe and a second set of information bits not contained in the first A-MPDU subframe; processing module 1301 is further configured to determine a second LDPC codeword based on the information bits of the first LDPC; further configured to punch the second set of information bits of the second LDPC codeword; further configured to generate at least one LDPC pre-transmitted codeword; and further configured to generate at least one LDPC retransmitted codeword.

[0355] The transmitting module 1302 is configured to transmit an A-MPDU, wherein the A-MPDU includes at least one A-MPDU subframe, the at least one A-MPDU subframe includes at least one first A-MPDU subframe, and the first A-MPDU subframe includes a first MPDU. The transmitting module 1302 is further configured to transmit at least one retransmitted LDPC codeword encoded from the at least one first A-MPDU subframe, wherein the at least one retransmitted LDPC codeword includes a punctured codeword, the punctured codeword being all or part of the encoded bits of the second information bit set in the second LDPC codeword after puncturing, and the second LDPC codeword being determined based on the information bits of the first LDPC codeword. For example, it is configured to perform the aforementioned S101 or S104.

[0356] The receiving module 1303 is used to receive acknowledgment feedback information, which indicates which MPDUs in the A-MPDU were not successfully received. For example, it is used to execute the aforementioned S104.

[0357] Optionally, a storage module 1304 may also be included.

[0358] In another embodiment, the transmitting device can be used to perform any function of the transmitting end in the aforementioned embodiment three. For example:

[0359] Processing module 1301 is configured to determine at least one first MPDU that needs to be retransmitted in a previously transmitted A-MPDU, wherein the at least one first MPDU is contained in at least one first A-MPDU subframe, and the first A-MPDU subframe includes at least one pre-transmitted LDPC codeword after scrambling and encoding, wherein the at least one pre-transmitted LDPC codeword includes a first LDPC codeword, and the information bits of the first LDPC codeword include information bits after scrambling a first set of information bits in the first A-MPDU subframe and a second set of information bits not contained in the first A-MPDU subframe; for example, it is configured to perform the aforementioned S303; processing module 1301 is further configured to determine a second LDPC codeword based on the information bits of the first LDPC; further configured to punch the scrambled second set of information bits of the second LDPC codeword; and further configured to scramble and then encode the first A-MPDU subframe to obtain the first LDPC codeword or the second LDPC codeword.

[0360] The transmitting module 1302 is configured to transmit an A-MPDU, wherein the A-MPDU includes at least one A-MPDU subframe, and a first A-MPDU subframe includes a first MPDU. The transmitting module 1302 is further configured to transmit at least one retransmitted LDPC codeword after scrambling and encoding the at least one first A-MPDU subframe, wherein the at least one retransmitted LDPC codeword includes a punctured codeword, the punctured codeword being all or part of the encoded bits of the scrambled second information bit set in the second LDPC codeword after puncturing, and the second LDPC codeword being determined based on the information bits of the first LDPC codeword. For example, it is configured to execute the aforementioned S301 or S304;

[0361] The receiving module 1303 is used to receive acknowledgment feedback information, which indicates which MPDUs in the A-MPDU were not successfully received. For example, it is used to execute the aforementioned S304.

[0362] In yet another embodiment, the transmitting device can be used to perform any function of the transmitting end in the aforementioned embodiment five. For example:

[0363] Processing module 1301 is configured to generate an Aggregated Media Access Control Protocol Data Unit (A-MPDU), wherein the A-MPDU includes at least one first A-MPDU subframe and at least one second A-MPDU subframe; a first A-MPDU subframe includes a first type MPDU; and a second A-MPDU subframe includes a second type MPDU; for example, to perform the aforementioned S501. Processing module 1301 is further configured to determine second encoding parameters based on a first encoding parameter determined from the encoding parameters of the previously transmitted first A-MPDU subframe, and based on a second length L2; for example, to perform the aforementioned S502. Processing module 1301 is further configured to encapsulate at least one first A-MPDU subframe and at least one second A-MPDU subframe into a data field of a Physical Layer Protocol Data Unit (PPDU) using the first encoding parameters and the second encoding parameters respectively; processing module 1301 is further configured to determine a second LDPC codeword based on the information bits of the first LDPC; further configured to puncture the scrambled second information bit set of the second LDPC codeword; and further configured to scramble the first A-MPDU subframe before encoding to obtain the first LDPC codeword or the second LDPC codeword.

[0364] The transmitting module 1302 transmits at least one first A-MPDU subframe, which includes a first type MPDU. The first A-MPDU subframe is encoded using pre-transmission coding parameters to encapsulate it into a pre-transmission PPDU, for example, to execute the aforementioned S500. The transmitting module 1302 is also configured to transmit at least one retransmitted LDPC codeword after scrambling and encoding the at least one first A-MPDU subframe. The at least one retransmitted LDPC codeword includes a punctured codeword, which is all or part of the coded bits of the scrambled second information bit set in the second LDPC codeword after puncturing. The second LDPC codeword is determined based on the information bits of the first LDPC codeword. For example, this is used to execute the aforementioned S301 or S304.

[0365] Optionally, the receiving module 1303 is used to receive acknowledgment feedback information, which is used to indicate which MPDUs in the A-MPDU were not successfully received.

[0366] In yet another embodiment, the transmitting device can be used to perform any function of the transmitting end in the aforementioned embodiment seven.

[0367] Processing module 1301: Used to generate physical layer protocol data unit (PPDU), the PPDU including a physical layer preamble and a data field, the data field including an A-MPDU, the A-MPDU including at least one retransmitted MPDU and at least one non-retransmitted MPDU, the physical layer preamble including various retransmission indication information.

[0368] Transmitting module 1302: Used to transmit Physical Layer Protocol Data Unit (PPDU).

[0369] The embodiments of this application are as follows: Figure 13 Taking the data transmission device shown as an example, the various modules in the data transmission device for the sending end will be described. It should be understood that the sending device for the sending end in the embodiments of this application has any of the functions of the sending end in the retransmission data sending method shown in any of Embodiments 1, 3, 5 or 7.

[0370] Figure 14 This is a schematic diagram of a receiving device provided in an embodiment of this application. The receiving device 1400 can be used in the receiving end or the chip in the receiving end of any one of Embodiments 2, 4, 6 or 7. The receiving device 1400 includes a processing module 1401, a transmitting module 1402 and a receiving module 1403.

[0371] In one embodiment, the receiving device can be used to perform any function of the receiving end in the aforementioned embodiment two, for example:

[0372] Processing module 1401 is configured to identify at least one first MPDU that needs to be retransmitted in a previously transmitted A-MPDU, wherein the first MPDU is contained in a first A-MPDU subframe of the A-MPDU; processing module 1401 is further configured to perform combined decoding or joint decoding on the at least one retransmitted LDPC codeword and at least one previously received pretransmitted LDPC codeword to obtain the first A-MPDU subframe, and is further configured to decode at least one pretransmitted LDPC codeword, and is further configured to decode at least one retransmitted LDPC codeword. For example, it is configured to perform the aforementioned S205 or S202.

[0373] The sending module 1402 is used to send an acknowledgment feedback frame, wherein the acknowledgment feedback is used to indicate which MPDUs in the A-MPDU were not successfully received. For example, it is used to perform the aforementioned S203.

[0374] The receiving module 1403 is configured to receive Aggregated Media Intervention Control Protocol Data Units (A-MPDUs), wherein each A-MPDU includes at least one A-MPDU subframe, and the at least one A-MPDU subframe includes a first A-MPDU subframe, which in turn includes a first MPDU. This is used, for example, to perform the aforementioned S201. The receiving module 1403 is also configured to receive at least one retransmitted LDPC codeword encoded from at least one first A-MPDU subframe, wherein the at least one retransmitted LDPC codeword includes a punctured codeword, which is all or part of the encoded bits of a second information bit set in a second LDPC codeword after puncturing the bit set. The second LDPC codeword is determined based on the information bits of the first LDPC codeword.

[0375] Optionally, a storage module 1404 may also be included.

[0376] In another embodiment, the transmitting device can be used to perform any function of the receiving end in the aforementioned embodiment four. For example:

[0377] Processing module 1401 is configured to determine at least one first MPDU that needs to be retransmitted in a previously transmitted A-MPDU, wherein one first MPDU is contained in a first A-MPDU subframe of the A-MPDU; processing module 1401 is further configured to perform combined decoding or joint decoding on the at least one retransmitted LDPC codeword and the at least one previously received pretransmitted LDPC codeword to obtain the first A-MPDU subframe; processing module 1401 is further configured to descramble the first A-MPDU subframe; optionally, processing module 1401 is further configured to determine decoding parameters and scrambling sequence. For example, it is used to execute the aforementioned S404 or S405;

[0378] The sending module 1402 is configured to send an acknowledgment feedback frame, wherein the acknowledgment feedback is used to indicate which MPDUs in the A-MPDU were not successfully received. For example, it is configured to perform the aforementioned S403;

[0379] The receiving module 1403 is configured to receive at least one retransmitted LDPC codeword after scrambling and encoding at least one first A-MPDU subframe transmitted by the transmitting end, and is also configured to receive Aggregated Media Intervention Control Protocol Data Unit (A-MPDU), wherein the A-MPDU includes at least one A-MPDU subframe. For example, it is used to execute the aforementioned S404 or S401.

[0380] In yet another embodiment, the transmitting device can be used to perform any of the functions of the receiving end in the aforementioned embodiment six. For example:

[0381] Processing module 1401 is configured to decode the PPDU using a first encoding parameter and a second encoding parameter respectively, to obtain the at least first A-MPDU subframe and the at least one second A-MPDU subframe. For example, it is configured to perform the aforementioned S602;

[0382] The receiving module 1403 is configured to receive a Physical Layer Protocol Data Unit (PPDU), wherein the data field of the PPDU includes a first portion encoded by at least one first A-MPDU subframe using a first encoding parameter, and a second portion encoded by at least one second A-MPDU subframe using a second encoding parameter. For example, it is configured to perform the aforementioned S601.

[0383] Optionally, the sending module 1402 is used to send confirmation feedback information to indicate which MPDUs were not successfully received.

[0384] In yet another embodiment, the transmitting device can be used to perform any function of the receiving end in the aforementioned embodiment seven.

[0385] Processing module 1401: used to parse physical layer protocol data unit (PPDU), the PPDU including physical layer preamble and data field, the data field including A-MPDU, the A-MPDU including at least one retransmitted MPDU and at least one non-retransmitted MPDU, the physical layer preamble including various retransmission indication information.

[0386] Receiver module 1403: Used to receive Physical Layer Protocol Data Units (PPDUs).

[0387] The embodiments of this application are as follows: Figure 14Taking the data transmission device shown as an example, the various modules in the data transmission device for the receiving end will be described. It should be understood that the receiving device for the receiving end in the embodiments of this application has any of the functions of the receiving end in any of the retransmission data receiving methods in Embodiments 2, 4, 6, or 7.

[0388] The transmitting device (for transmitting end) or receiving device (for receiving end) provided in the embodiments of this application can be implemented in various product forms. For example, the transmitting device or receiving device can be configured as a general-purpose processing system; for example, the transmitting device or receiving device can be implemented using a general bus architecture; for example, the transmitting device or receiving device can be implemented using an application-specific integrated circuit (ASIC), and so on. The following provides several possible product forms of the transmitting device or receiving device in the embodiments of this application. It should be understood that the following are merely examples and do not limit the possible product forms of the embodiments of this application to these.

[0389] In one example Figure 15 A schematic block diagram of a transmitting device 1500 according to an embodiment of this application is shown. The device 1500 of this application embodiment can be a transmitting end in any of the above method embodiments, or it can be one or more chips within a transmitting end. The device 1500 can be used to perform some or all of the functions of the transmitting end in the above method embodiments.

[0390] Device 1500 can be used to perform some or all of the functions of the transmitting end in the above method embodiments. Device 1500 may include a processor 1510, baseband circuitry 1530, radio frequency circuitry 1540, and antenna 1550. Optionally, device 1500 may also include a memory 1520. The various components of device 1500 are coupled together via bus 1560, which includes a data bus, a power bus, a control bus, and a status signal bus. However, for clarity, all buses are labeled as bus system 1560 in the figures.

[0391] The processor 1510 can be used to control the transmitting end, to execute the processing performed by the transmitting end in the above embodiments, to execute the processing procedures involving the transmitting end in the above method embodiments and / or other processes used in the technology described in this application, and can also run an operating system, be responsible for managing the bus, and execute programs or instructions stored in memory.

[0392] The baseband circuit 1530, the radio frequency circuit 1540, and the antenna 1550 can be used to support the transmission and reception of information between the transmitter and the receiver involved in the above embodiments, so as to support wireless communication between the transmitter and the receiver.

[0393] In one example, at the transmitting end, the retransmitted or initial MPDU is processed by processor 1510. After being encapsulated into an A-MPDU according to the protocol by baseband circuit 1530, it undergoes baseband processing such as scrambling and encoding. Further, it is processed by RF circuit 1540 through analog-to-digital conversion, filtering, amplification, and up-conversion before being transmitted via antenna 1550. In another example, acknowledgment feedback information sent from the receiving end is received by antenna 1550. After being processed by RF circuit 1540 through filtering, amplification, down-conversion, and digitization, it is decoded by baseband circuit 1530 and decapsulated according to the protocol before being processed by processor 1510 to recover the acknowledgment feedback information sent by the receiving end.

[0394] The memory 1520 can be used to store the program code and data of the transmitting end. The memory 1520 can be... Figure 15 The storage module 1530 is included. Understandably, the baseband circuit 1530, the radio frequency circuit 1540, and the antenna 1550 can also be used to support communication between the transmitter and other network entities, for example, to support communication between the transmitter and network elements on the core network side. Figure 15 The memory 1520 is shown as separate from the processor 1510; however, those skilled in the art will readily understand that the memory 1520 or any portion thereof may be located outside the channel resource allocation device 1500. For example, the memory 1520 may include transmission lines and / or computer artifacts separate from the wireless node, all of which can be accessed by the processor 1510 via the bus interface 1560. Alternatively, the memory 1520 or any portion thereof may be integrated into the processor 1510, for example, as a cache and / or general-purpose registers.

[0395] Understandable, Figure 15 Only a simplified design of the transmitter is shown. For example, in practical applications, the transmitter can include any number of transmitters, receivers, processors, memory, etc., and all transmitters that can implement this invention are within the scope of protection of this invention.

[0396] This application describes in detail the schematic structure of the receiving device according to embodiments. In one example... Figure 16 A schematic block diagram of a receiving device 1600 according to an embodiment of this application is shown. The device 1600 of this application embodiment can be a receiving end in any of the above method embodiments, or it can be one or more chips within the receiving end. The device 1600 can be used to perform some or all of the functions of the receiving end in the above method embodiments.

[0397] Device 1600 can be used to perform some or all of the functions of the receiving end in any of the above method embodiments. Device 1600 may include a processor 1610, baseband circuitry 1630, radio frequency circuitry 1640, and antenna 1650. Optionally, device 1600 may also include a memory 1620. The various components of device 1600 are coupled together via bus 1660, which includes a data bus, a power bus, a control bus, and a status signal bus. However, for clarity, all buses are labeled as bus system 1660 in the figures.

[0398] The processor 1610 can be used to control the receiving end, to perform the processing performed by the receiving end in the above embodiments, to perform the processing procedures involving the sending end in the above method embodiments and / or other processes used in the technology described in this application, and can also run an operating system, be responsible for managing the bus, and can execute programs or instructions stored in memory.

[0399] The baseband circuit 1630, the radio frequency circuit 1640, and the antenna 1650 can be used to support the transmission and reception of information between the receiver and the transmitter involved in the above embodiments, so as to support wireless communication between the receiver and the transmitter. In one example, the signal transmitted from the transmitter is received by antenna 1650, processed by RF circuitry including filtering, amplification, down-conversion, and digitization, and then processed by baseband circuitry including decoding and decapsulation according to the protocol. Finally, processor 1610 processes the signal to recover the service data and signaling information transmitted by the transmitter. For example, the receiver decodes and decapsulates the received PPDU to obtain an A-MPDU, which is then parsed by the processor to obtain the retransmitted MPDU or the initial transmission MPDU. In another example, the receiver's acknowledgment feedback can be processed by processor 1610, processed by baseband circuitry 1630 including protocol encapsulation and encoding, and further processed by RF circuitry 1640 including analog conversion, filtering, amplification, and up-conversion before being transmitted via antenna 1650. Memory 1620 can be used to store the transmitter's program code and data; memory 1620 can be a storage module. Understandably, baseband circuitry 1630, RF circuitry 1640, and antenna 1650 can also support communication between the receiver and other network entities.

[0400] Understandable, Figure 16Only a simplified design of the receiver is shown. For example, in practical applications, the receiver can include any number of transmitters, receivers, processors, memories, etc., and all receivers that can implement the present invention are within the scope of protection of the present invention. The processor involved in the above-described apparatus 1500 and apparatus 1600 can be a general-purpose processor, such as a general-purpose central processing unit (CPU), a network processor (NP), a microprocessor, etc., or an application-specific integrated circuit (ASIC), or one or more integrated circuits used to control the execution of the program of the present application. It can also be a digital signal processor (DSP), a field-programmable gate array (FPGA), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components. The controller / processor can also be a combination that implements computing functions, such as including one or more microprocessor combinations, a combination of DSP and microprocessor, etc. The processor usually performs logical and arithmetic operations based on program instructions stored in memory.

[0401] The memory involved in the aforementioned devices 1500 and 1600 may also store an operating system and other application programs. Specifically, the program may include program code, which includes computer operation instructions. More specifically, the aforementioned memory may be read-only memory (ROM), other types of static storage devices capable of storing static information and instructions, random access memory (RAM), other types of dynamic storage devices capable of storing information and instructions, disk storage, etc. The memory may be a combination of the above storage types. Furthermore, the aforementioned computer-readable storage medium / memory may be located within a processor, external to a processor, or distributed across multiple entities including a processor or processing circuitry. The aforementioned computer-readable storage medium / memory may be embodied in a computer program product. For example, a computer program product may include a computer-readable medium within packaging material.

[0402] This application also provides a chip system including a processor for supporting a transmitter or a second receiver to implement the functions involved in any of the above embodiments, such as generating or processing data and / or information involved in the above methods. In one possible design, the chip system may further include a memory for program instructions and data necessary for the transmitter or receiver. This chip system may be composed of chips or may include chips and other discrete devices.

[0403] This application also provides a processor for coupling with a memory to perform the methods and functions involving a transmitting end or a receiving end in any of the above embodiments.

[0404] This application also provides a computer program product containing instructions that, when run on a computer, cause the computer to perform the methods and functions related to the sending end or receiving end in any of the above embodiments.

[0405] This application also provides an apparatus for performing the methods and functions involving a receiving end or a sending end in any of the above embodiments.

[0406] This application also provides a wireless communication system, which includes at least one transmitter and at least one receiver as described in any of the above embodiments.

[0407] In the several embodiments provided in this application, it should be understood that the disclosed systems, apparatuses, and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative. For instance, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be an indirect coupling or communication connection through some interfaces, apparatuses, or units, and may be electrical, mechanical, or other forms. As another possible product form, the data transmission device can also be implemented using: Field-Programmable Gate Array (FPGA), Programmable Logic Device (PLD), controller, state machine, gate logic, discrete hardware components, any other suitable circuit, or any combination of circuits capable of performing the various functions described throughout this application.

[0408] In the above embodiments, implementation can be achieved, in whole or in part, through software, hardware, firmware, or any combination thereof. When implemented in software, it can be implemented, in whole or in part, as a computer program product. The computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, all or part of the processes or functions described in this application are generated. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions can be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another. For example, the computer instructions can be transmitted from one website, computer, server, or data center to another website, computer, server, or data center via wired (e.g., coaxial cable, fiber optic, or digital subscriber line) or wireless (e.g., infrared, wireless, or microwave). The computer-readable storage medium can be any available medium accessible to a computer or a data storage device such as a server or data center that integrates one or more available media. The available medium can be a magnetic medium (e.g., floppy disk, hard disk, magnetic tape), an optical medium (e.g., DVD), or a semiconductor medium (e.g., a solid-state drive).

Claims

1. A method for sending retransmitted data, applied at a sending end, characterized in that, include: Identify a first MPDU that needs to be retransmitted in a previously transmitted Aggregated Media Intervention Control Protocol Data Unit (A-MPDU), the first MPDU being contained in a first A-MPDU subframe of the A-MPDU; The first LDPC codeword encoded after the first A-MPDU subframe includes a first LDPC codeword. The first LDPC codeword is an LDPC codeword whose information bits span across the first A-MPDU subframe and other A-MPDU subframes adjacent to the first A-MPDU subframe. The information bits of the first LDPC codeword correspond to a first set of information bits included in the first A-MPDU subframe and a second set of information bits not included in the first A-MPDU subframe. The second LDPC codeword is obtained based on the information bits of the first LDPC codeword, wherein the information bits of the second LDPC codeword include the first information bit set and the second information bit set; At least one retransmitted LDPC codeword encoded after the first A-MPDU subframe is transmitted, and the one or more retransmitted LDPC codewords include punctured codewords, wherein the punctured codewords are all or part of the encoded bits of the second information bit set in the second LDPC codeword after puncturing.

2. The method according to claim 1, characterized in that, The at least one retransmitted LDPC codeword further includes at least one unpunctured codeword, wherein all information bits corresponding to the at least one unpunctured codeword are contained in the first A-MPDU subframe.

3. The method according to claim 1 or 2, characterized in that, The information bits of the first LDPC codeword correspond to the first information bit set in the first A-MPDU subframe and the second information bit set not included in the first A-MPDU subframe, including: the information bits of the first LDPC codeword are information bits after scrambling the first information bit set and the second information bit set using a scrambling sequence; or, the information bits of the first LDPC codeword are the first information bit set and the second information bit set.

4. The method according to claim 1 or 2, characterized in that, The process of obtaining the second LDPC codeword based on the information bits of the first LDPC codeword includes: Obtain the previously transmitted first LDPC codeword as the second LPDC codeword; or, The information bits of the first LDPC codeword are encoded using a retransmission check matrix to obtain the second LDPC codeword; the retransmission check matrix is ​​the same as or has a preset relationship with the check matrix used in the first LDPC codeword.

5. The method according to claim 1 or 2, characterized in that, The information bits of the first LDPC codeword include: the first information bit set and the second information bit set; obtaining the second LDPC codeword based on the information bits of the first LDPC codeword includes: The information bits of the first LDPC codeword are scrambled using a retransmission scrambling sequence to obtain scrambled bits to be encoded; the scrambled information bits to be encoded are then encoded using a retransmission parity check matrix to obtain the second LDPC codeword; wherein the retransmission scrambling sequence is the same as the scrambling sequence used to scramble the information bits of the first LDPC codeword; and the retransmission parity check matrix is ​​the same as or has a preset relationship with the parity check matrix of the first LDPC codeword.

6. The method according to claim 1 or 2, characterized in that, At least one retransmission codeword encoded in the first A-MPDU subframe is carried in a physical layer protocol data unit (PPDU). The leader of the PPDU includes one or more of the following: MPDU retransmission indication, wherein the MPDU retransmission indication takes a first value, which is used to indicate that the PPDU includes a retransmitted MPDU; Modulation coding scheme indication, wherein the modulation coding scheme indication is a special value, the special value being used to indicate that the PPDU includes only retransmitted MPDU; The retransmission MPDU length indicator is used to indicate the total length of the A-MPDU subframes in the PPDU that include the retransmission MPDU; Scrambler seed indicator, used to indicate the scrambler seed used for scrambling retransmitted MPDUs.

7. A method for receiving retransmitted data, applied at a receiving end, characterized in that, include: Identify the first MPDU that needs to be retransmitted in the previously transmitted first aggregated media access control protocol data unit (A-MPDU), the first MPDU being contained in the first A-MPDU subframe of the A-MPDU; The first LDPC codeword encoded after the first A-MPDU subframe includes a first LDPC codeword. The first LDPC codeword is an LDPC codeword whose information bits span across the first A-MPDU subframe and other A-MPDU subframes adjacent to the first A-MPDU subframe. The information bits of the first LDPC codeword correspond to a first set of information bits included in the first A-MPDU subframe and a second set of information bits not included in the first A-MPDU subframe. The receiver receives at least one retransmitted LDPC codeword encoded after the first A-MPDU subframe is retransmitted by the transmitter. The at least one retransmitted codeword includes a punctured codeword. The punctured codeword is all or part of the encoded bits of the second information bit set of the second LDPC codeword after being punctured. The second LDPC codeword is generated based on the information bits of the first LDPC codeword. The information bits of the second LDPC codeword include the first information bit set and the second information bit set. The maximum likelihood ratio (LLR) of the at least one retransmitted LDPC codeword and the at least one previously received LDPC codeword is combined and decoded or jointly decoded to obtain the first A-MPDU subframe.

8. The method according to claim 7, characterized in that, The at least one retransmitted LDPC codeword further includes at least one unpunctured codeword, wherein all information bits corresponding to the at least one unpunctured codeword are contained in the first A-MPDU subframe.

9. The method according to claim 7 or 8, characterized in that, The information bits of the first LDPC codeword correspond to a first set of information bits included in the first A-MPDU subframe and a second set of information bits not included in the first A-MPDU subframe; the combined decoding or joint decoding includes: The second set of information bits is padded to the punched codeword to obtain the second LDPC codeword; A retransmission check matrix is ​​used to decode the at least one retransmitted LDPC codeword and the at least one previously received pretransmitted LDPC codeword to obtain the first A-MPDU subframe; wherein the retransmission check matrix is ​​the same as or has a preset relationship with the check matrix used to decode the previously transmitted pretransmitted LDPC codeword.

10. The method according to claim 7 or 8, characterized in that, The information bits of the first LDPC codeword are the information bits obtained by scrambling the first information bit set and the second information bit set using a scrambling sequence; The aforementioned merged decoding or joint decoding includes: The second set of information bits is padded to the punched codeword to obtain the second LDPC codeword; The at least one retransmitted LDPC codeword and the at least one previously received LDPC codeword are combined or jointly decoded using a retransmission check matrix to obtain the scrambled first A-MPDU subframe. The scrambled first A-MPDU subframe is descrambled using a retransmission scrambling sequence to obtain the descrambled first A-MPDU subframe. The retransmission check matrix is ​​the same as or has a preset relationship with the check matrix used to decode the previously received first A-MPDU subframe; the retransmission scrambling sequence is the same as the scrambling sequence used to descramble the previously received scrambled first A-MPDU subframe.

11. The method according to claim 9, characterized in that, The merged decoding or joint decoding further includes: deleting the second set of information bits from the information bits after merged decoding or joint decoding to obtain the first A-MPDU subframe.

12. The method according to claim 7 or 8, characterized in that, At least one retransmission codeword corresponding to the first A-MPDU encoding is carried in the physical layer protocol data unit; the PPDU preamble includes one or more of the following combinations: MPDU retransmission indication, wherein the MPDU retransmission indication takes a first value, which is used to indicate that the PPDU includes a retransmitted MPDU; Modulation coding scheme indication, wherein the modulation coding scheme indication is a special value, the special value being used to indicate that the PPDU includes only retransmitted MPDU; The retransmission MPDU length indicator is used to indicate the total length of the A-MPDU subframes in the PPDU that include the retransmission MPDU; Scrambler seed indicator, used to indicate the scrambler seed used for scrambling retransmitted MPDUs.

13. A data retransmission sending device, applied at a sending end, characterized in that, include: The processing module is configured to determine a first MPDU that needs to be retransmitted in a previously transmitted Aggregated Media Intervention Control Protocol Data Unit (A-MPDU), the first MPDU being contained in a first A-MPDU subframe of the A-MPDU; The first LDPC codeword encoded after the first A-MPDU subframe includes a first LDPC codeword. The first LDPC codeword is an LDPC codeword whose information bits span across the first A-MPDU subframe and other A-MPDU subframes adjacent to the first A-MPDU subframe. The information bits of the first LDPC codeword correspond to a first set of information bits included in the first A-MPDU subframe and a second set of information bits not included in the first A-MPDU subframe. The processing module is further configured to obtain a second LDPC codeword based on the information bits of the first LDPC codeword, wherein the information bits of the second LDPC codeword include the first information bit set and the second information bit set; The transmitting module is configured to transmit at least one retransmitted LDPC codeword after encoding the first A-MPDU subframe, wherein the at least one retransmitted LDPC codeword includes a punctured codeword, and the punctured codeword is all or part of the encoded bits of the second information bit set in the second LDPC codeword after puncturing.

14. The transmitting device according to claim 13, characterized in that, The at least one retransmitted LDPC codeword further includes at least one unpunctured codeword, wherein all information bits corresponding to the at least one unpunctured codeword are contained in the first A-MPDU subframe.

15. The transmitting device according to claim 13 or 14, characterized in that, The information bits of the first LDPC codeword correspond to the first information bit set in the first A-MPDU subframe and the second information bit set not included in the first A-MPDU subframe, including: the information bits of the first LDPC codeword are information bits after scrambling the first information bit set and the second information bit set using a scrambling sequence; or, the information bits of the first LDPC codeword are the first information bit set and the second information bit set.

16. The transmitting device according to claim 13 or 14, characterized in that, The second LDPC codeword is obtained based on the information bits of the first LDPC codeword. The processing module is further configured to encode the information bits of the first LDPC codeword using a retransmission check matrix to obtain the second LDPC codeword; the retransmission check matrix is ​​the same as the check matrix used for the first LDPC codeword; or, The processing module is further configured to encode the information bits of the first LDPC codeword using a retransmission check matrix to obtain the second LDPC codeword; the retransmission check matrix and the check matrix of the first LDPC have a preset relationship.

17. The transmitting device according to claim 13 or 14, characterized in that, The information bits of the first LDPC codeword include: the first information bit set and the second information bit set; the second LDPC codeword is obtained based on the information bits of the first LDPC codeword; The processing module is further configured to scramble the information bits of the first LDPC codeword using a retransmission scrambling sequence to obtain scrambled bits to be encoded; and to encode the scrambled information bits to be encoded using a retransmission parity check matrix to obtain the second LDPC codeword; wherein the retransmission scrambling sequence is the same as the scrambling sequence used to scramble the information bits of the first LDPC codeword; and the retransmission parity check matrix is ​​the same as the parity check matrix of the first LDPC codeword; or, The processing module is further configured to scramble the information bits of the first LDPC codeword using a retransmission scrambling sequence to obtain scrambled bits to be encoded; and to encode the scrambled information bits to be encoded using a retransmission parity check matrix to obtain the second LDPC codeword; wherein the retransmission scrambling sequence is the same as the scrambling sequence used to scramble the information bits of the first LDPC codeword in previous transmissions; and the retransmission parity check matrix has a preset relationship with the parity check matrix of the first LDPC codeword.

18. The transmitting device according to claim 13 or 14, characterized in that, At least one retransmission codeword encoded in the first A-MPDU subframe is carried in a physical layer protocol data unit (PPDU). The leader of the PPDU includes one or more of the following: MPDU retransmission indication, wherein the MPDU retransmission indication takes a first value, which is used to indicate that the PPDU includes a retransmitted MPDU; Modulation coding scheme indication, wherein the modulation coding scheme indication is a special value, the special value being used to indicate that the PPDU includes only retransmitted MPDU; The retransmission MPDU length indicator is used to indicate the total length of the A-MPDU subframes in the PPDU that include the retransmission MPDU; Scrambler seed indicator, used to indicate the scrambler seed used for scrambling retransmitted MPDUs.

19. A receiving device for retransmitted data, employing a receiving end, characterized in that, include: The processing module is configured to determine the first MPDU that needs to be retransmitted in the previously transmitted first aggregated media access control protocol data unit (A-MPDU), wherein the first MPDU is contained in the first A-MPDU subframe of the A-MPDU; The first LDPC codeword encoded after the first A-MPDU subframe includes a first LDPC codeword. The first LDPC codeword is an LDPC codeword whose information bits span across the first A-MPDU subframe and other A-MPDU subframes adjacent to the first A-MPDU subframe. The information bits of the first LDPC codeword correspond to a first set of information bits in the first A-MPDU subframe and a second set of information bits not included in the first A-MPDU subframe. The receiving module is configured to receive at least one retransmitted LDPC codeword encoded by the first A-MPDU subframe retransmitted by the transmitting end, wherein the at least one retransmitted codeword includes a punctured codeword, and the punctured codeword is all or part of the encoded bits of the second information bit set of the second LDPC codeword after puncturing; the second LDPC codeword is generated based on the information bits of the first LDPC codeword, and the information bits of the second LDPC codeword include the first information bit set and the second information bit set; The processing module is also used to perform combined decoding or joint decoding on the at least one retransmitted LDPC codeword and the at least one previously received pretransmitted LDPC codeword to obtain the first A-MPDU subframe.

20. The receiving device according to claim 19, characterized in that, The at least one retransmitted LDPC codeword further includes at least one unpunctured codeword, wherein all information bits corresponding to the at least one unpunctured codeword are contained in the first A-MPDU subframe.

21. The receiving device according to claim 19 or 20, characterized in that, The information bits of the first LDPC codeword correspond to the first set of information bits in the first A-MPDU subframe and the second set of information bits not included in the first A-MPDU subframe; The processing module is further configured to pad the second information bit set to the punched codeword to obtain the second LDPC codeword, and to decode the at least one retransmitted LDPC codeword and the at least one previously received pretransmitted LDPC codeword using retransmission decoding parameters to obtain the first A-MPDU subframe; wherein the retransmission decoding parameters are the same as the decoding parameters used to decode the previously transmitted first LDPC codeword.

22. The receiving device according to claim 20, characterized in that, The information bits of the first LDPC codeword are the information bits obtained by scrambling the first information bit set and the second information bit set using a scrambling sequence; the processing module is further configured to: The second set of information bits is padded to the punched codeword to obtain the second LDPC codeword; Using retransmission decoding parameters, the at least one retransmitted LDPC codeword and the at least one previously received pretransmitted LDPC codeword are merged or jointly decoded to obtain the scrambled first A-MPDU subframe. The scrambled first A-MPDU subframe is descrambled using a retransmission random scrambling code sequence to obtain the descrambled first A-MPDU subframe. The retransmission decoding parameters are the same as the decoding parameters used to decode the previously received first A-MPDU subframe. The retransmission scrambling sequence is the same as the scrambling sequence used to descramble the previously received scrambled first A-MPDU subframe.

23. The receiving device according to claim 19 or 20, characterized in that, The processing module is further configured to: delete the second set of information bits from the information bits after merged decoding or joint decoding to obtain the first A-MPDU subframe.

24. The receiving device according to claim 19 or 20, characterized in that, At least one retransmission codeword corresponding to the first A-MPDU encoding is carried in the physical layer protocol data unit; the PPDU preamble includes one or more of the following combinations: MPDU retransmission indication, wherein the MPDU retransmission indication takes a first value, which is used to indicate that the PPDU includes a retransmitted MPDU; Modulation coding scheme indication, wherein the modulation coding scheme indication is a special value, the special value being used to indicate that the PPDU includes only retransmitted MPDU; The retransmission MPDU length indicator is used to indicate the total length of the A-MPDU subframes in the PPDU that include the retransmission MPDU; Scrambler seed indicator, used to indicate the scrambler seed used for scrambling retransmitted MPDUs.

25. A method for constructing an A-MPDU, applied at a transmitting end, characterized in that, include: Generate an Aggregated Media Intervention Control Protocol Data Unit (A-MPDU), wherein the A-MPDU includes at least one first A-MPDU subframe and at least one second A-MPDU subframe; A first A-MPDU subframe includes a retransmitted Media Access Control Protocol Data Unit (MPDU); a second A-MPDU subframe includes an initial MPDU. Wherein, the total length of the at least one first A-MPDU subframe is a first length L1; the total length of the at least one second A-MPDU subframe is a second length L2; and the total length of the A-MPDU subframe is a third length L3. The first encoding parameter and the second encoding parameter are used respectively to encapsulate the at least one first A-MPDU subframe and the at least one second A-MPDU subframe into the data field of a physical layer protocol data unit (PPDU). Wherein, for the first A-MPDU subframe, at least one retransmitted LDPC codeword after encoding the first A-MPDU subframe includes a punctured codeword, wherein the punctured codeword is all or part of the encoded bits of the second information bit set in the second LDPC codeword after puncturing; the second LDPC codeword is obtained based on the information bits of the first LDPC codeword; the first LDPC codeword is an LDPC codeword whose information bits span the first A-MPDU subframe and other A-MPDU subframes adjacent to the first A-MPDU subframe, wherein the information bits of the first LDPC codeword correspond to the first information bit set included in the first A-MPDU subframe and the second information bit set not included in the first A-MPDU subframe; The second encoding parameter is determined based on the second length L2; Send the PPDU.

26. The method according to claim 25, characterized in that, The first encoding parameter is determined based on the encoding parameters of the previously transmitted first A-MPDU subframe; The first encoding parameters include the encoding code length and the encoding code rate, which are the same as the encoding code length and encoding code rate of the at least one previously transmitted first A-MPDU subframe; or, The first encoding parameter includes a check matrix, which has a preset relationship with the check matrix of the at least one previously transmitted first A-MPDU subframe.

27. The method according to claim 25 or 26, characterized in that, The data field of the PPDU includes: N1 OFDM symbols corresponding to the at least one first A-MPDU subframe, and N2 OFDM symbols corresponding to the at least one second A-MPDU subframe; The step of determining the second encoding parameter based on the second length L2 includes: The number of OFDM symbols N2 corresponding to the at least one second A-MPDU subframe is determined based on the second length L2; The number of coding bits required for the at least one second A-MPDU subframe is determined based on the number of OFDM symbols N2. ; based on Determine the second encoding parameter.

28. The method according to claim 27, characterized in that, ； When the data uses the STBC method ,otherwise ; The number of information bits that each OFDM symbol can carry; The length of the service field in the PPDU structure; The number of coded bits that each OFDM symbol can carry.

29. The method according to claim 28, characterized in that, based on Determining the second encoding parameter includes: determining the encoding code length included in the second encoding parameter based on the preset correspondence between encoded bits and code length.

30. The method according to claim 25 or 26, characterized in that, The leading edge of the PPDU includes a length indicator, which indicates either the first length L1 or the second length L2.

31. A method for receiving a PPDU, applied at a receiving end, characterized in that, include: A Physical Layer Protocol Data Unit (PPDU) is received, wherein the data field of the PPDU includes a first part encoded by at least one first A-MPDU subframe using a first encoding parameter, and a second part encoded by at least one second A-MPDU subframe using a second encoding parameter; a first A-MPDU subframe includes a retransmitted MPDU, and a second A-MPDU subframe includes an initial transmitted MPDU. Wherein, the total length of the at least one first A-MPDU subframe is a first length L1; the total length of the at least one second A-MPDU subframe is a second length L2; and the total length of the A-MPDU subframe is a third length L3. The first part includes at least one retransmitted LDPC codeword, which includes a punctured codeword. The punctured codeword is all or part of the encoded bits of the second information bit set in the second LDPC codeword after being punctured. The second LDPC codeword is obtained based on the information bits of the first LDPC codeword. The first LDPC codeword is an LDPC codeword whose information bits span the first A-MPDU subframe and other A-MPDU subframes adjacent to the first A-MPDU subframe. The information bits of the first LDPC codeword correspond to the first information bit set included in the first A-MPDU subframe and the second information bit set not included in the first A-MPDU subframe. The PPDU is decoded using the first encoding parameter and the second encoding parameter respectively to obtain the at least one first A-MPDU subframe and the at least one second A-MPDU subframe; The second encoding parameter is determined based on the second length L2.

32. The method according to claim 31, characterized in that: The first encoding parameter is determined based on the encoding parameters of the previously transmitted first A-MPDU subframe; The first encoding parameters include the encoding code length and the encoding code rate, which are the same as the encoding code length and encoding code rate of the at least one previously transmitted first A-MPDU subframe; or, The first encoding parameter includes a check matrix, which has a preset relationship with the check matrix of the at least one previously transmitted first A-MPDU subframe.

33. The method according to claim 31 or 32, characterized in that, The method further includes: The number N2 of OFDM symbols corresponding to the at least one second MPDU is determined based on the second length L2; The number of encoded bits required for the at least one second MPDU is determined based on the number of OFDM symbols N2. ; based on Determine the second encoding parameter.

34. The method according to claim 33, characterized in that, ； When the data uses the STBC method ,otherwise ; The number of information bits that each OFDM symbol can carry; The length of the service field in the PPDU structure; The number of coded bits that each OFDM symbol can carry.

35. The method according to claim 34, characterized in that, based on Determining the second encoding parameter includes: determining the encoding code length included in the second encoding parameter based on the preset correspondence between encoded bits and code length.

36. The method according to claim 31 or 32, characterized in that, The PPDU leader includes a length indicator, which is used to indicate the first length L1 or the second length L2; The method further includes: determining the second length L2 based on a length indication.

37. The method according to claim 31 or 32, characterized in that, The method further includes: The media access control layer feeds back the second length L2 from the physical layer.

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