Data transmission method and apparatus

Abstract

The present application provides a data transmission method and apparatus, capable of reducing the retransmission delay of transport blocks. The method comprises: when a first transport block is not successfully received, a terminal sends HARQ feedback to a network device, wherein the HARQ feedback indicates that the first transport block is not successfully received; the network device monitors the HARQ feedback from the terminal, and when the HARQ feedback received by the network device indicates that the terminal has successfully received the first transport block, sends, to the terminal, first downlink control information used for scheduling a second transport block for initial transmission or second downlink control information, wherein the second downlink control information indicates whether the first transport block needs to be retransmitted; when receiving the first downlink control information or the second downlink control information, the terminal sends, to the network device, request information used for requesting retransmission of the first transport block; the network device learns, on the basis of the request information, that decoding of the HARQ feedback from the terminal is incorrect, and sends the first transport block for retransmission to the terminal.

Description

Methods and apparatus for data transmission

[0001] This application claims priority to Chinese Patent Application No. 202510206394.4, filed on February 24, 2025, entitled "Method and Apparatus for Data Transmission", the entire contents of which are incorporated herein by reference. Technical Field

[0002] This application relates to the field of communications, and more specifically, to a method and apparatus for data transmission. Background Technology

[0003] The 5th generation (5G) new radio (NR) standard uses retransmission mechanisms under the medium access control (MAC) layer, radio link control (RLC) layer, and packet data convergence protocol (PDCP) layer.

[0004] The Hybrid Automatic Repeat Request (HARQ) mechanism at the MAC layer is the most commonly used retransmission mechanism. It achieves fast retransmission by having the receiver immediately report the success or failure of the transmission to the sender. However, after reaching the maximum number of retransmissions, the HARQ mechanism abandons MAC retransmission, and its decoding error rate can reach around 1%. For data services with ultra-high reliability and ultra-low latency requirements, such as data transmission services in ultra-reliable low-latency communication (URLLC) scenarios, the HARQ mechanism cannot meet the requirements.

[0005] The sender abandons retransmission of the MAC layer transport block in the following two situations: (1) the maximum number of retransmissions at the MAC layer is reached; (2) a HARQ feedback error occurs. The reasons for the error include the sender not performing CRC verification on the HARQ feedback information from the receiver or the CRC verification failing. For example, when the number of bits in the HARQ is small, cyclic redundancy check (CRC) is not performed, and the sender mistakenly interprets a negative acknowledgement (NACK) as an acknowledgement (ACK) and transmits a new transport block. Retransmission caused by HARQ feedback errors needs to be performed at the RLC layer, which requires the multiplexing and reassembly of MAC protocol data units (PDUs), resulting in a large retransmission delay. Therefore, how to reduce the retransmission delay of the transport block is an urgent technical problem to be solved. Summary of the Invention

[0006] This application provides a data transmission method and apparatus that can reduce the retransmission delay of transmission blocks.

[0007] Firstly, a method for data transmission is provided, which can be executed by a terminal. Unless otherwise specified, the term "terminal" in this application can refer to the terminal itself, a component in the terminal (e.g., a processor, chip, or chip system), or a logic module or software that can implement all or part of the terminal's functions.

[0008] The method includes: sending first feedback information to a network device, the first feedback information indicating that a first transport block was not successfully received; receiving first downlink control information from the network device, the first downlink control information being used to schedule a second transport block, the data in the second transport block being initial transmission data; or, receiving second downlink control information from the network device, the second downlink control information indicating whether the first transport block needs to be retransmitted; and sending request information to the network device, the request information being used to request retransmission of the first transport block.

[0009] Based on the above technical solution, the terminal sends a first feedback message to the network device indicating that the first transport block was not successfully received. If the network device decodes the first feedback message from the terminal incorrectly and considers that the terminal has successfully received the first transport block, the network device sends a first downlink control message to the terminal indicating whether to schedule the initial transmission of the second transport block, or a second downlink control message indicating whether the first transport block needs to be retransmitted. The terminal then sends a request message to the network device to request the retransmission of the first transport block based on the first or second downlink control message. This allows the network device to know that the decoding of the first feedback message from the terminal was incorrect and to send a retransmitted first transport block to the terminal. This avoids retransmitting the first transport block at the RLC layer due to transmission failure, thereby reducing the retransmission latency of the transport block. Furthermore, the terminal can perform soft-merge decoding with the received retransmitted first transport block and the first transport block buffered in the buffer, thereby enhancing decoding reliability.

[0010] In conjunction with the first aspect, some implementations of the first aspect further include: receiving a retransmitted first transport block from the network device. In this implementation, the network device determines, based on a request from the terminal, that a decoding error has occurred in the first feedback information from the terminal. The network device then sends a retransmitted first transport block to the terminal. This avoids retransmitting the first transport block at the RLC layer due to transmission failure, thereby reducing the retransmission latency of the transport block. Furthermore, the terminal can perform soft-merge decoding with the received retransmitted first transport block and the first transport block buffered in the buffer, thereby enhancing decoding reliability.

[0011] In conjunction with the first aspect, some implementations of the first aspect further include: receiving third downlink control information from the network device, the third downlink control information indicating retransmission of the first transport block and / or resources for retransmitting the first transport block. Optionally, the network device sends the retransmitted first transport block to the terminal on the resources for retransmitting the first transport block; the terminal receives the retransmitted first transport block from the network device on the resources for retransmitting the first transport block.

[0012] In conjunction with the first aspect, in certain implementations of the first aspect, when the third downlink control information indicates a retransmission of the first transport block, receiving the retransmitted first transport block from the network device includes: receiving the retransmitted first transport block from the network device on the resource indicated by the first downlink control information. In this optional implementation, the size of the resource indicated by the first downlink control information may be greater than or equal to the size of the resource required to retransmit the first transport block.

[0013] In conjunction with the first aspect, some implementations of the first aspect further include: receiving configuration information from the network device, the configuration information indicating the sending time of the request information; and sending the request information to the network device including: sending the request information to the network device at the specified sending time. Based on this implementation, sending the request information according to the configuration information can avoid the additional transmission overhead caused by dynamically indicating the sending time of the request information.

[0014] In conjunction with the first aspect, in some implementations of the first aspect, the time at which the request information is sent is at an interval T1 between the time interval of receiving the first downlink control information, or the time at which the request information is sent is at an interval T2 between the time interval of the start time of the time-domain resource indicated by the first downlink control information, wherein the time at which the request information is sent is earlier than the start time. Based on this implementation, the terminal can send a retransmission request before the time-domain resource indicated by the first downlink control information, allowing the network device to be aware of the decoding error of the first feedback information (HARQ feedback of the first transport block) and send the retransmitted first transport block to the terminal. This can avoid retransmitting the first transport block at the RLC layer, thereby reducing the retransmission latency of the first transport block.

[0015] In conjunction with the first aspect, in some implementations of the first aspect, the time at which the request information is sent is the time interval T3 between the time interval T3 of receiving the second downlink control information. Optionally, the time at which the request information is sent is the time interval T4 between the time interval T4 of sending the first feedback information. Based on this implementation, the terminal can determine the time of sending the request information based on the transmission time of the second downlink control information or the transmission time of the first feedback information, without needing to dynamically indicate the time of sending the request information, thereby saving transmission overhead.

[0016] In conjunction with the first aspect, in some implementations of the first aspect, before sending the request information to the network device, the method further includes: receiving the second transport block from the network device according to the first downlink control information; sending the request information to the network device includes: sending the request information and second feedback information to the network device, the second feedback information indicating whether the second transport block was successfully received, and the request information and the second feedback information being carried on the same uplink physical channel. In this implementation, the request information for requesting retransmission of the first transport block is sent together with the second feedback information (HARQ feedback information of the second transport block).

[0017] Secondly, a method for data transmission is provided, which can be executed by a network device. Unless otherwise specified, "network device" in this application can refer to the network device itself, a component in the network device (e.g., a processor, chip, or chip system), or a logic module or software that can implement all or part of the functions of the network device.

[0018] The method includes: monitoring first feedback information from a terminal, the first feedback information indicating whether a first transport block has been successfully received; sending first downlink control information to the terminal, the first downlink control information being used to schedule a second transport block, the data in the second transport block being initial transmission data; or sending second downlink control information to the terminal, the second downlink control information indicating whether the first transport block needs to be retransmitted; and receiving request information from the terminal, the request information being used to request retransmission of the first transport block.

[0019] The method provided in the second aspect is the same as the method on the network device side as in the first aspect, and its beneficial effects can be referred to in the first aspect.

[0020] In conjunction with the second aspect, in some implementations of the second aspect, sending the first downlink control information to the terminal, or sending the second downlink control information to the terminal, includes: sending the first downlink control information to the terminal, or sending the second downlink control information to the terminal, when the first feedback information is received and the first feedback information indicates that the terminal has successfully received the first transport block.

[0021] In conjunction with the second aspect, some implementations of the second aspect further include: sending the retransmitted first transmission block to the terminal according to the request information.

[0022] In conjunction with the second aspect, some implementations of the second aspect further include: sending third downlink control information to the terminal, the third downlink control information indicating retransmission of the first transport block and / or resources for retransmission of the first transport block.

[0023] In conjunction with the second aspect, in some implementations of the second aspect, when the third downlink control information indicates a retransmission of the first transport block, sending the retransmitted first transport block to the terminal includes: sending the retransmitted first transport block to the terminal on the resource indicated by the first downlink control information.

[0024] In conjunction with the second aspect, some implementations of the second aspect further include: sending configuration information to the terminal, wherein the configuration information indicates the time at which the request information is sent.

[0025] In conjunction with the second aspect, in some implementations of the second aspect, the time at which the request information is sent is the time interval T1 between the time interval of receiving the first downlink control information, or the time interval T2 between the time interval of receiving the first downlink control information and the start time of the time-domain resource indicated by the first downlink control information. Wherein, the time at which the request information is sent is earlier than the start time.

[0026] In conjunction with the second aspect, in some implementations of the second aspect, the time at which the request information is sent is the time interval T3 between the time interval for receiving the second downlink control information.

[0027] In conjunction with the second aspect, in some implementations of the second aspect, before receiving the request information from the terminal, the method further includes: sending the second transmission block to the terminal;

[0028] Receiving request information from the terminal includes: receiving request information and second feedback information from the terminal, wherein the second feedback information indicates whether the second transport block was successfully received, and the request information and the second feedback information are carried on the same uplink physical channel.

[0029] In conjunction with the second aspect, in some implementations of the second aspect, sending the first downlink control information to the terminal includes: upon receiving the first feedback information, in which the first feedback information indicates that the terminal has not successfully received the first transmission block, but the first transmission block has reached the maximum number of retransmissions, sending the first downlink control information to the terminal.

[0030] In conjunction with the second aspect, some implementations of the second aspect further include: sending the second transmission block to the terminal.

[0031] Thirdly, a communication device is provided that can be applied to the terminal described in the first aspect. The communication device includes a transceiver module for implementing the receiving and sending functions of the method described in the first aspect.

[0032] Fourthly, a communication device is provided that can be applied to the network device described in the second aspect. The communication device includes a transceiver module for implementing the receiving and sending functions of the method described in the second aspect.

[0033] Fifthly, a communication device is provided, comprising: a processor configured to implement the method as described in the first aspect or any possible implementation thereof. Optionally, the communication device further comprises an interface circuit configured to receive signals from other communication devices and transmit them to the processor, or to send signals from the processor to other communication devices.

[0034] A sixth aspect provides a communication device comprising: a processor configured to implement the method as described in the second aspect or any possible implementation thereof. Optionally, the communication device further comprises an interface circuit configured to receive signals from other communication devices and transmit them to the processor, or to send signals from the processor to other communication devices.

[0035] In a seventh aspect, a communication system is provided, comprising a terminal for performing the method as described in the first aspect, and a network device for performing the method as described in the second aspect.

[0036] Eighthly, a computer-readable storage medium is provided, the computer-readable medium storing a computer program; when the computer program is executed by a processor, the methods of the first and second aspects or any possible implementation of the first and second aspects are performed.

[0037] Ninthly, a computer program product is provided, the computer program product comprising a computer program that, when executed, causes the method in the first and second aspects or any possible implementation of the first and second aspects to be performed.

[0038] The solutions provided in the third to ninth aspects above are used to implement or cooperate with the methods provided in the first or second aspects above, and therefore can achieve the same or corresponding beneficial effects as the first or second aspects, which will not be elaborated here. Attached Figure Description

[0039] Figure 1 is a schematic diagram of the architecture of a communication system provided in an embodiment of this application;

[0040] Figure 2 is a schematic flowchart of a data transmission method provided in an embodiment of this application;

[0041] Figures 3A and 3B are schematic diagrams showing the timing of the request information being sent;

[0042] Figure 4 is a schematic diagram of an example of a data transmission method provided in an embodiment of this application;

[0043] Figures 5 to 8 are schematic diagrams illustrating another example of the data transmission method provided in the embodiments of this application;

[0044] Figure 9 is a schematic flowchart of another data transmission method provided in an embodiment of this application;

[0045] Figures 10A and 10B are schematic diagrams showing the timing of the request information being sent.

[0046] Figures 11 and 12 are schematic diagrams illustrating another example of the data transmission method provided in the embodiments of this application;

[0047] Figures 13 and 14 are schematic diagrams of the possible communication devices provided in the embodiments of this application. Detailed Implementation

[0048] Figure 1 is a schematic diagram of the architecture of a communication system 1000 provided in an embodiment of this application. As shown in Figure 1, the communication system 1000 includes a radio access network (RAN) 100, wherein the RAN 100 includes at least one RAN node (110a and 110b in Figure 1, collectively referred to as 110), and may also include at least one terminal (120a-120j in Figure 1, collectively referred to as 120). The RAN 100 may also include other RAN nodes, such as wireless relay devices and / or wireless backhaul devices (not shown in Figure 1). The terminal 120 is wirelessly connected to the RAN node 110. Terminals and RAN nodes can be interconnected via wired or wireless means. The communication system 1000 may also include a core network 200. The RAN node 110 is connected to the core network 200 via wireless or wired means. The core network equipment in core network 200 and the RAN node 110 in RAN 100 can be independent and different physical devices, or they can be the same physical device that integrates the logical functions of the core network equipment and the logical functions of the RAN node. Communication system 1000 may also include Internet 300.

[0049] RAN100 can be an evolved universal terrestrial radio access (E-UTRA) system, an NR system, a 6th generation (6G) radio access system, or a future radio access system as defined in the 3rd generation partnership project (3GPP), or a WiFi system. RAN100 can also include two or more of the above-mentioned different radio access systems. RAN100 can also be an open RAN (O-RAN).

[0050] RAN nodes, also known as radio access network devices, RAN entities, or access nodes, are used to help terminals access communication systems wirelessly. In one application scenario, an RAN node can be a base station, an evolved NodeB (eNodeB), a transmission reception point (TRP), a next-generation NodeB (gNB) in a 5G mobile communication system, a next-generation base station in a 6G mobile communication system, a base station in a future mobile communication system, or an access node in a WiFi system. RAN nodes can be macro base stations (as shown in Figure 1, 110a), micro base stations or indoor stations (as shown in Figure 1, 110b), relay nodes, or donor nodes.

[0051] In another application scenario, multiple RAN nodes can collaborate to help terminals achieve wireless access, with different RAN nodes implementing different functions of the base station. For example, a RAN node can be a central unit (CU), a distributed unit (DU), or a radio unit (RU). Here, the CU performs the functions of the base station's Radio Resource Control (RRC) and PDCP, and can also perform the functions of the Service Data Adaptation Protocol (SDAP). The DU performs the functions of the base station's Radio Link Control (RAN) and MAC layers, and can also perform some or all of the physical layer functions. For specific descriptions of these protocol layers, refer to the relevant 3GPP technical specifications. The RU can be used to implement radio frequency signal transmission and reception. The CU and DU can be two independent RAN nodes or integrated into the same RAN node, such as within a baseband unit (BBU). RUs can be included in radio frequency equipment, such as in a remote radio unit (RRU) or an active antenna unit (AAU). CUs can be further divided into two types of RAN nodes: CU-control plane and CU-user plane.

[0052] In different systems, RAN nodes may have different names. For example, in an O-RAN system, a CU can be called an open CU (O-CU), a DU can be called an open DU (O-DU), and an RU can be called an open RU (O-RU). The RAN nodes in the embodiments of this application can be implemented through software modules, hardware modules, or a combination of software and hardware modules. For example, a RAN node can be a server loaded with the corresponding software modules. The embodiments of this application do not limit the specific technology or device form used in the RAN nodes. For ease of description, a base station is used as an example of a RAN node in the following description.

[0053] A terminal is a device with wireless transceiver capabilities, capable of sending signals to or receiving signals from a base station. Terminal 120 can also be referred to as terminal equipment, user equipment (UE), mobile station, mobile terminal, etc. Terminals can be widely used in various scenarios, such as NTN, device-to-device (D2D), vehicle-to-everything (V2X) communication, machine-type communication (MTC), Internet of Things (IoT), virtual reality, augmented reality, industrial control, autonomous driving, telemedicine, smart grids, smart furniture, smart offices, smart wearables, smart transportation, smart cities, etc. Terminals can be mobile phones, tablets, computers with wireless transceiver capabilities, wearable devices, vehicles, drones, helicopters, airplanes, ships, robots, robotic arms, smart home devices, etc. The terminal can also be a communication module with satellite communication capabilities, a satellite phone or its components, or a satellite communication terminal, such as a very small aperture terminal (VSAT) (commonly referred to as a VSAT terminal), a portable station, a fixed station, a vehicle-mounted or airborne satellite communication terminal, etc. It should be understood that the satellite communication terminal can serve as a micro base station to further provide data interfaces to accessed user equipment. The embodiments of this application do not limit the specific technology or equipment form used in the terminal.

[0054] Base stations and terminals can be fixed or mobile. They can be deployed on land, including indoors or outdoors, handheld or vehicle-mounted; they can also be deployed on water; and they can be deployed on aircraft, balloons, and satellites. The embodiments of this application do not limit the application scenarios of the base stations and terminals.

[0055] The roles of base stations and terminals can be relative. For example, the helicopter or drone 120i in Figure 1 can be configured as a mobile base station. For terminals 120j that access the wireless access network 100 through 120i, terminal 120i is a base station; however, for base station 110a, 120i is a terminal, meaning that 110a and 120i communicate via a wireless air interface protocol. Of course, 110a and 120i can also communicate via a base station-to-base station interface protocol. In this case, relative to 110a, 120i is also a base station. Therefore, both base stations and terminals can be collectively referred to as communication devices. 110a and 110b in Figure 1 can be called communication devices with base station functions, and 120a-120j in Figure 1 can be called communication devices with terminal functions.

[0056] Communication between base stations and terminals, between base stations, and between terminals can be conducted using licensed spectrum, unlicensed spectrum, or both simultaneously. Communication can be conducted using spectrum below 6 GHz, spectrum above 6 GHz, or both simultaneously. The embodiments of this application do not limit the spectrum resources used for wireless communication.

[0057] In the embodiments of this application, the functions of the base station can be executed by modules (such as chips) within the base station, or by a control subsystem that includes base station functions. This control subsystem, including base station functions, can be a control center in the aforementioned application scenarios such as smart grids, industrial control, intelligent transportation, and smart cities. Similarly, the functions of the terminal can be executed by modules (such as chips or modems) within the terminal, or by a device that includes terminal functions.

[0058] In this application, the base station sends downlink signals or downlink information to the terminal, with the downlink information carried on the downlink channel; the terminal sends uplink signals or uplink information to the base station, with the uplink information carried on the uplink channel. To communicate with the base station, the terminal needs to establish a radio connection on a cell controlled by the base station. The cell with which the terminal has established a radio connection is called the terminal's serving cell. When the terminal communicates with this serving cell, it is also susceptible to interference from signals from neighboring cells.

[0059] It is understood that in the embodiments of this application, the physical downlink shared channel (PDSCH), physical downlink control channel (PDCCH), physical uplink shared channel (PUSCH), and physical uplink control channel (PUCCH) are only examples of downlink data channel, downlink control channel, uplink data channel, and uplink control channel, respectively. In different systems and different scenarios, data channels and control channels may have different names, and the embodiments of this application do not limit this.

[0060] RAN node 110 or core network equipment can also be network nodes with artificial intelligence (AI) capabilities, providing AI services to terminals or other network devices. For example, RAN node 110 can be an AI node, computing power node, or RAN node with AI capabilities in the radio access network. Similarly, core network equipment can be an AI node, computing power node, or core network element with AI capabilities in the core network.

[0061] To facilitate understanding of the embodiments of this application, some terms or concepts involved in the embodiments of this application will be explained first.

[0062] 1. Forward Error Correction (FEC): Forward error correction is an error control method in which a signal is pre-encoded according to a certain algorithm before being sent into the transmission channel, and redundant codes with the characteristics of the signal itself are added; the receiving end decodes the received signal according to the corresponding algorithm, thereby finding and correcting the error codes generated during transmission.

[0063] 2. Automatic Repeat Request (ARQ): The receiving end uses CRC information to determine the correctness of the received data and sends the result back to the sending end. If the decoding is incorrect, the sending end will retransmit the data after receiving the feedback information until the receiving end receives it correctly.

[0064] The 5G NR standard uses retransmission mechanisms under the MAC layer, RLC layer, and PDCP layer protocols.

[0065] 1. MAC layer retransmission

[0066] The HARQ technology at the MAC layer combines the retransmission mechanisms of FEC and ARQ. The HARQ mechanism first uses the FEC algorithm to encode the channel, adding redundant information with error detection and correction capabilities to the transmitted information. The receiving end decodes the received signal according to the corresponding inverse algorithm. If an error is detected, it attempts to correct it to the best of its ability. If the error can be corrected, the data transmission is successful. If it cannot be corrected, the ARQ mechanism is used to notify the sending end to retransmit. If the decoding error persists, a retransmission is requested again until the reception is correct.

[0067] The advantage of HARQ over using FEC alone lies in reducing the complexity and computational overhead of the encoding and decoding process. While FEC allows for the recovery of damaged data without retransmission, achieving high transmission efficiency with FEC alone requires significantly increased computational overhead and complexity in the encoding and decoding process. Therefore, combining FEC and ARQ complements each other, reducing the complexity and computational overhead of the encoding and decoding process while improving transmission efficiency.

[0068] HARQ uses a stop-and-wait protocol to send data. In the stop-and-wait protocol, after the sender transmits a transport block (TB), it pauses and waits for an acknowledgment (HARQ feedback). The receiver uses 1 bit of information to indicate whether the TB corresponds to an ACK or NACK. However, the sender pausing to wait for acknowledgment after each transmission results in low throughput. Therefore, multiple parallel HARQ processes / stop-and-wait processes are needed: while one HARQ process is waiting for an acknowledgment, the sender can use another HARQ process to continue sending data.

[0069] The transmitting end indicates the HARQ process number in the downlink control information (DCI) to inform the receiving end which process the current uplink or downlink transmission belongs to. Each HARQ process corresponds to a new data indicator (NDI) value, which is either 0 or 1. The transmitting end uses the inversion of the NDI value to indicate to the receiving end whether the current transmission is an initial transmission or a retransmission. If the NDI value transmitted this time is opposite to the NDI value transmitted previously (NDI inversion), it indicates that the data transmitted this time is initial data; if the NDI value transmitted this time is the same as the NDI value transmitted previously, it indicates that the data transmitted this time is retransmission data.

[0070] II. RLC Layer Retransmission

[0071] The ARQ mechanism of the RLC layer complements the retransmission mechanism of the MAC layer. Compared to the HARQ mechanism, the transmission frequency of feedback signaling in the RLC layer is lower, thus requiring less overhead to achieve a lower feedback error rate. Therefore, combining the HARQ mechanism of the MAC layer and the ARQ mechanism of the RLC layer can meet the data transmission needs of different application scenarios. The HARQ mechanism is managed by the MAC layer. When data transmission fails at the MAC layer, a HARQ retransmission request is sent. If the maximum number of retransmissions exceeds the MAC layer's limit, the ARQ mechanism of the RLC layer sends an ARQ retransmission request; or, if the MAC layer mistakenly considers the data transmission correct due to a HARQ feedback error and does not retransmit, the RLC's ARQ mechanism can still send an ARQ retransmission request.

[0072] III. PDCP Retransmission

[0073] PDCP layer retransmission is mainly used in scenarios where terminals switch cells across base stations. Since the relevant configurations and caches of lower-layer (RLC and MAC layers) protocols are cleared during the handover process, but the PDCP layer is not cleared, the PDCP layer retransmission function can ensure that data is not lost due to handover.

[0074] This application provides a data transmission method in which a terminal sends a request message to a network device to request the retransmission of a transport block. This allows the network device to be aware of decoding errors in the HARQ feedback from the terminal and to send the retransmitted transport block to the terminal. This can avoid RLC layer retransmissions caused by transport block transmission failures, thereby reducing the retransmission latency of the transport block.

[0075] Figure 2 is a schematic flowchart illustrating a data transmission method 200 provided in an embodiment of this application. In this application, a base station is used as an example of a network device for description. Unless otherwise specified, the term "base station" in this application can refer to the base station itself, a component of the base station (e.g., a processor, chip, or chip system), or a logical module or software capable of implementing all or part of the base station's functions. Similarly, the term "terminal" in this application can refer to the terminal itself, a component within the terminal (e.g., a processor, chip, or chip system), or a logical module or software capable of implementing all or part of the terminal's functions.

[0076] The chip can be a modem chip, also known as a baseband chip; or a system-on-a-chip (SoC) containing a modem core; or a system-in-package (SoC). Furthermore, the processing performed by a single execution entity can be divided among multiple execution entities, which can be logically and / or physically separated. For example, the processing performed by a base station can be divided among at least one of a CU, DU, RU, etc.

[0077] S210, the terminal sends a first feedback message to the base station, indicating that the first transport block was not successfully received. Correspondingly, the base station monitors the first feedback message from the terminal, which indicates whether the first transport block was successfully received. The first feedback message can be understood as a HARQ feedback for the first transport block, and this HARQ feedback is NACK.

[0078] Specifically, the base station sends a first transmission block to the terminal, and correspondingly, the terminal receives the first transmission block from the base station. If the terminal fails to receive the first transmission block, it sends a first feedback message to the base station indicating that it has not successfully received the first transmission block. Here, "the terminal failed to receive the first transmission block" can be understood as either the terminal not receiving the first transmission block at all, or the terminal failing to decode the received first transmission block.

[0079] For example, if the base station does not perform CRC verification on the first feedback information from the terminal or the CRC verification fails, the base station may decode the first feedback information from the terminal incorrectly. For example, the first feedback information received by the base station indicates that the first transport block has been successfully received.

[0080] S220, the base station sends first downlink control information to the terminal. This first downlink control information is used to schedule a second transport block, and the data in the second transport block is initial transmission data. Correspondingly, the terminal receives the first downlink control information from the base station. For example, during the previous data transmission, the downlink control information indicating NDI for scheduling the first transport block sent by the base station to the terminal was 0, and the first downlink control information indicating NDI was 1. Compared with the previous NDI, the NDI indicated by the first downlink control information has flipped, indicating that the second transport block scheduled this time is initial transmission data. It should be noted that, in this application, initial transmission data can also be referred to as newly transmitted data or data transmitted for the first time.

[0081] Optionally, when the base station receives the first feedback information, and the received first feedback information indicates that the terminal has successfully received the first transport block, the base station sends first downlink control information to the terminal. In this example, the base station decodes the first feedback information from the terminal incorrectly. The received first feedback information indicates that the terminal has successfully received the first transport block, and the first feedback information sent by the terminal can be understood as a NACK for the first transport block; in other words, the base station decodes the NACK from the terminal for the first transport block incorrectly, mistakenly decoding the NACK fed back by the terminal as ACK.

[0082] S230, the terminal sends a request message to the base station, which requests a retransmission of the first transport block. Correspondingly, the base station receives the request message from the terminal.

[0083] It should be noted that, since the first downlink control information is used to schedule the second transmission block of the initial transmission, the terminal believes that the base station has misdecoded the first feedback information sent by the terminal and mistakenly decoded the NACK fed back by the terminal as ACK; therefore, the terminal sends a request information to the base station to request the retransmission of the first transmission block.

[0084] Optionally, in S240, the base station sends the retransmitted first transmission block to the terminal. Correspondingly, the terminal receives the retransmitted first transmission block from the base station; after receiving the retransmitted first transmission block, the terminal performs soft-merge decoding on the retransmitted first transmission block and the first transmission block buffered in the buffer.

[0085] Specifically, after the base station receives a request from the terminal to retransmit the first transmission block, the base station learns that the decoding of the first feedback information from the terminal is incorrect. Therefore, the base station sends the retransmitted first transmission block to the terminal.

[0086] In the technical solution provided in this application embodiment, the terminal sends a first feedback message to the base station indicating that the first transport block was not successfully received. If the base station decodes the first feedback message from the terminal incorrectly and considers that the terminal has successfully received the first transport block, the base station sends a first downlink control message to the terminal indicating that the initial transmission of the second transport block is scheduled. Based on the first downlink control message, the terminal sends a request message to the base station to request the retransmission of the first transport block. This allows the base station to know that the decoding of the first feedback message from the terminal was incorrect, and then sends a retransmitted first transport block to the terminal. This avoids retransmission of the first transport block at the RLC layer due to the failure of the first transport block transmission, thereby reducing the retransmission latency of the transport block. In addition, the terminal can perform soft-merge decoding with the received retransmitted first transport block and the first transport block buffered in the buffer, thereby enhancing the decoding reliability.

[0087] Optionally, in step S241, after the base station receives the request information from the terminal, and before the base station sends the first retransmission block to the terminal, the base station sends third downlink control information to the terminal. This third downlink control information indicates the retransmission of the first transmission block and / or resources for retransmitting the first transmission block. Correspondingly, the terminal receives the third downlink control information from the base station.

[0088] In the first implementation, after the base station receives a request from the terminal to retransmit the first transport block, the base station sends third downlink control information to the terminal instructing the retransmission of the first transport block. Upon receiving the third downlink control information, the terminal receives the retransmitted first transport block from the base station. In this example, the third downlink control information only instructs the retransmission of the first transport block and does not indicate the resources used for retransmitting the first transport block. In this case, the resources indicated by the first downlink control information (i.e., the resources used to schedule the second transport block) can be used to retransmit the first transport block.

[0089] For example, the base station retransmits the first transport block to the terminal on the resource indicated by the first downlink control information; correspondingly, the terminal receives the retransmitted first transport block from the base station on the resource indicated by the first downlink control information. In this example, the size of the resource indicated by the first downlink control information may be greater than or equal to the size of the resource required to retransmit the first transport block.

[0090] In the second implementation, after the base station receives a request from the terminal to retransmit the first transport block, the base station sends a third downlink control message to the terminal instructing the retransmission of the first transport block and the resources for retransmitting the first transport block. Upon receiving the third downlink control message, the terminal receives the retransmitted first transport block from the base station.

[0091] For example, the base station retransmits the first transport block to the terminal on the resources indicated by the third downlink control information for retransmitting the first transport block; correspondingly, the terminal receives the retransmitted first transport block from the base station on the resources indicated by the third downlink control information for retransmitting the first transport block. In this example, the size of the resources indicated by the first downlink control information may be smaller than the size of the resources required to retransmit the first transport block, therefore the base station needs to reallocate the resources used for retransmitting the first transport block.

[0092] Optionally, the resources used to transmit the first transport block may also be indicated by downlink control information other than the third downlink control information.

[0093] Optionally, the choice between the first and second implementation methods can be determined through predefined or default methods. For example, if the size of the resources used to transmit the second transport block is greater than or equal to the size of the resources required to transmit the first transport block, the first implementation method is used by default; if the size of the resources used to transmit the second transport block is less than the size of the resources required to transmit the first transport block, the second implementation method is used by default.

[0094] Optionally, the base station sends configuration information to the terminal, which indicates the time at which the request information is sent. Correspondingly, the terminal receives the configuration information from the base station; the terminal sends the request information to the base station at the time indicated by the configuration information. In this application, the time at which the request information is sent can be understood as the start time of the time-domain resources used to send the request information.

[0095] For example, the time when the request information is sent is the time interval T1 between the time when the first downlink control information is received. This can be understood as the time when the request information is sent after the time when the first downlink control information is received, with an interval of T1. The time when the first downlink control information is received can be either the start time or the end time of receiving the first downlink control information.

[0096] For example, the request information is sent at a time interval T2 from the start time of the time-domain resource indicated by the first downlink control information, wherein the request information is sent earlier than the start time of the time-domain resource indicated by the first downlink control information. This can be understood as the request information being sent before the start time of the time-domain resource indicated by the first downlink control information, with an interval of T2. Based on this example, the terminal can send a retransmission request before the time-domain resource indicated by the first downlink control information, allowing the base station to be aware of a decoding error in the first feedback information (HARQ feedback of the first transport block) and send the retransmitted first transport block to the terminal. This avoids retransmitting the first transport block at the RLC layer, thereby reducing the retransmission latency of the first transport block.

[0097] Figures 3A and 3B are schematic diagrams of the transmission time of the request information. In Figure 3A, the transmission time of the request information is the time interval T1 between the time interval of receiving the first downlink control information and the time interval T2 between the time interval of the time domain resource indicated by the first downlink control information.

[0098] Optionally, T1 and T2 are predefined by the protocol or pre-configured by the base station to the terminal via signaling. After receiving the first downlink control information from the base station, the terminal determines the transmission time of the request information based on the time of receiving the first downlink control information and T1; or, after receiving the first downlink control information from the base station, the terminal determines the transmission time of the request information based on the start time of the time domain resources indicated by the first downlink control information and T2.

[0099] In this application, the first transport block can be referred to as TB1, and the second transport block can be referred to as TB2. Figure 4 is a schematic diagram of an example of a data transmission method provided by an embodiment of this application. In this example, a HARQ feedback decoding error occurs, and the base station mistakenly decodes the NACK returned by the terminal for TB1 as ACK.

[0100] Step 1: At time t0, the base station sends a PDCCH to the terminal. This PDCCH is used to schedule TB1. The DCI indicator NDI carried by this PDCCH is 0. Compared with the previous NDI, the current NDI has been flipped, indicating that the data included in this TB1 transmission is newly transmitted data. Correspondingly, the terminal receives the PDCCH from the base station and receives TB1 from the base station on the PDSCH corresponding to the PDCCH.

[0101] Step 2: If the terminal fails to receive TB1 from the base station, the terminal sends a NACK for TB1 to the base station at time t1. Correspondingly, the base station receives the NACK from the terminal. The terminal's failure to receive TB1 from the base station can be understood as either a failure to decode the received TB1, or that the terminal did not receive TB1 at all.

[0102] Step 3: After receiving the NACK from the terminal, the base station sends a PDCCH to the terminal at time t2. This PDCCH is used to schedule TB1. The DCI indicator carried by this PDCCH is NDI=0. Compared with the previous NDI, the current NDI has not flipped, indicating that the data included in this TB1 transmission is retransmitted data. Correspondingly, the terminal receives the PDCCH from the base station and receives TB1 from the base station on the PDSCH corresponding to the PDCCH.

[0103] Step 4: If the terminal fails to receive TB1 from the base station, the terminal sends a first feedback message to the base station at time t3. This first feedback message is a NACK feedback for TB1. Correspondingly, the base station monitors the first feedback message from the terminal.

[0104] Step 5: If a decoding error occurs in the first feedback information, the base station decodes NACK to ACK, assuming the terminal has successfully received TB1. At time t4, the base station sends the first downlink control information to the terminal. This first downlink control information is used to schedule TB2. This first downlink control information indicates that NDI = 1, meaning that the NDI has been flipped compared to the previous one, indicating that the data included in this TB2 transmission is newly transmitted data. Correspondingly, the terminal receives the first downlink control information from the base station.

[0105] Step 6: After receiving the first downlink control information sent by the base station at time t4, the NDI indicated by the first downlink control information flips, indicating that the base station is about to transmit new data. This suggests that the first feedback information sent at time t3 had a decoding error, and the base station mistakenly decoded NACK as ACK. The terminal sends a request information to the base station at time t5, which requests retransmission of TB1. Correspondingly, the base station receives the request information from the terminal. Time t5 is after time t4 and before the time domain resources indicated by the first downlink control information sent by the base station at time t4. It can be understood that the first downlink control information is carried on the PDCCH, and the time domain resources indicated by the first downlink control information are the time domain resources of the PDSCH scheduled by the PDCCH.

[0106] Optionally, the base station sends configuration information to the terminal, which indicates the time (t5) at which the request information is sent. Correspondingly, the terminal receives the configuration information from the base station; at the time indicated by the configuration information, the terminal sends the request information to the base station.

[0107] For example, the time when the request information is sent is the time interval T1 between the time interval of the first downlink control information sent by the receiving base station at time t4.

[0108] For example, the time when the request information is sent is T2, which is an interval of time between the start time of the time domain resource indicated by the first downlink control information sent by the base station at time t4. The time when the request information is sent is earlier than the start time of the time domain resource indicated by the first downlink control information sent by the base station at time t4.

[0109] Step 7: After receiving the request information from the terminal, the base station learns that a decoding error has occurred in the first feedback information. At time t6, the base station sends third downlink control information to the terminal, which instructs for the retransmission of TB1. For example, this third downlink control information indicates that NDI = 0, and NDI is flipped again. It should be noted that this NDI flip does not indicate a new transmission, but rather a retransmission of TB1. Correspondingly, the terminal receives the third downlink control information from the base station and continues to store the undecoded TB1 in the buffer.

[0110] Step 8: In the first implementation, since the first downlink control information sent by the base station at time t4 indicates the resources used for transmitting TB2, the base station sends a retransmitted TB1 to the terminal on the resources used for transmitting TB2. In the second implementation, the base station reconfigures the resources used for retransmitting TB1. For example, the third downlink control information in step 7 also indicates the resources used for retransmitting TB1, and the base station sends the retransmitted TB1 to the terminal on the resources indicated by the third downlink control information. Correspondingly, the terminal receives the retransmitted TB1 from the base station. After receiving the retransmitted TB1, the terminal performs soft-merging decoding on the retransmitted TB1 and the TB1 buffered in the buffer. Optionally, in the second implementation, the third downlink control information and the information indicating the resources used for retransmitting TB1 can be sent separately, and this is not limited.

[0111] It should be noted that whether to use the first or second implementation method can be determined through predefinition or default. For example, if the size of the resources used to transmit TB2 is greater than or equal to the size of the resources required to transmit TB1, the first implementation method is used by default; if the size of the resources used to transmit TB2 is less than the size of the resources required to transmit TB1, the second implementation method is used by default.

[0112] Optionally, after step S210, if the base station receives first feedback information from the terminal, indicating that the terminal failed to receive the first transmission block but the first transmission block has reached the maximum retransmission count, the base station sends first downlink control information to the terminal. This first downlink control information is used to schedule the second transmission block, and the data in the second transmission block is the initial transmission data. In this optional implementation, the base station correctly decodes the first feedback information (NACK for the first transmission block) from the terminal, but the first transmission block has reached the maximum retransmission count. It should be noted that the first transmission block reaching the maximum retransmission count can be understood as the first transmission block reaching the maximum retransmission count at the MAC layer.

[0113] For example, after receiving the first downlink control information for scheduling the second transport block, the terminal, since the data in the second transport block is initial transmission data, assumes that the base station has misdecoded the first feedback information sent by the terminal, mistakenly decoding the terminal's NACK as ACK; therefore, the terminal sends a request to the base station to request retransmission of the first transport block. After the base station receives the request from the terminal to request retransmission of the first transport block, since the base station correctly received the first feedback information from the terminal, and the first transport block has reached the maximum number of retransmissions at the MAC layer, the base station abandons retransmission of the first transport block. For example, the base station uses the resources scheduled by the first downlink control information to send the second transport block to the terminal; correspondingly, the terminal receives the second transport block from the base station according to the first downlink control information.

[0114] Figure 5 is a schematic diagram of another example of the data transmission method provided in the embodiments of this application. In this example, no HARQ feedback decoding error occurred, and the base station successfully received the NACK for TB1 from the terminal. However, since TB1 reached the maximum number of retransmissions at the MAC layer, the base station abandoned the retransmission of TB1.

[0115] Steps 1 through 4 can be found in Figure 4, and will not be repeated here.

[0116] Step 5: The base station successfully receives the first feedback information (no decoding error occurred). However, since TB1 has reached the maximum retransmission count of the MAC layer, the base station abandons the retransmission of TB1. At time t4, the base station sends the first downlink control information to the terminal. This first downlink control information is used to schedule TB2. This first downlink control information indicates that NDI = 1. Compared with the previous NDI, the current NDI has been flipped, indicating that the data in TB2 transmitted this time is newly transmitted data. Correspondingly, the terminal receives the first downlink control information from the base station.

[0117] Step 6: After receiving the first downlink control information sent by the base station at time t4, the terminal, due to the NDI indicating the first downlink control information flipping, indicating that the base station is about to transmit new data, believes that the first feedback information sent at time t3 has a decoding error, and the base station mistakenly decoded NACK as ACK. The terminal then sends a request information to the base station at time t5, which requests retransmission of TB1. Here, time t5 is after time t4 and before the time domain resource indicated by the first downlink control information sent by the base station at time t4.

[0118] Optionally, the base station sends configuration information to the terminal, which indicates the time (t5) at which the request information is sent. Correspondingly, the terminal receives the configuration information from the base station; at the time indicated by the configuration information, the terminal sends the request information to the base station.

[0119] For example, the time when the request information is sent is the time interval T1 between the time interval of the first downlink control information sent by the receiving base station at time t4.

[0120] For example, the time when the request information is sent is T2, which is an interval of time between the start time of the time domain resource indicated by the first downlink control information sent by the base station at time t4. The time when the request information is sent is earlier than the start time of the time domain resource indicated by the first downlink control information sent by the base station at time t4.

[0121] Step 7: After receiving the request information from the terminal, the base station, having received the first feedback information and with TB1 reaching the maximum retransmission count at the MAC layer, decides to abandon the retransmission of TB1. The base station then sends TB2 to the terminal on the PDSCH scheduled by the first downlink control information; correspondingly, the terminal receives TB2 on the PDSCH scheduled by the first downlink control information. In this example, the base station does not send the third downlink control information, indicating that no decoding error occurred with the first feedback information, and the base station successfully received the first feedback information, but abandons the retransmission of TB1.

[0122] Step 8: After receiving the newly transmitted TB2, the terminal clears TB1 from the buffer and decodes TB2. Alternatively, the terminal does not need to wait to receive TB2. After sending the request information, the terminal can start a waiting timer. If the third downlink control information sent by the base station has not been received after the waiting timer expires, TB1 is cleared from the buffer. Alternatively, if the terminal does not detect a PDCCH with the same HARQ process number as TB1 before receiving TB2, TB1 is cleared from the buffer.

[0123] In the third implementation, after the terminal receives the first downlink control information from the base station, the base station uses the resources scheduled by the first downlink control information to send a second transport block to the terminal. The terminal receives the second transport block from the base station according to the first downlink control information. The terminal sends request information and second feedback information to the base station. The request information is used to request the retransmission of the first transport block, and the second feedback information indicates whether the second transport block was successfully received. The request information and the second feedback information are carried on the same uplink physical channel. Correspondingly, the base station receives the request information and the second feedback information from the terminal. After receiving the request information from the terminal to request the retransmission of the first transport block, the base station sends a third downlink control information to the terminal indicating the resources for retransmitting the first transport block. After receiving the third downlink control information, the terminal receives the retransmitted first transport block from the base station. In this optional implementation, the request information for requesting the retransmission of the first transport block is sent together with the second feedback information. The uplink physical channel can be PUCCH or PUSCH. The second feedback information can be understood as the HARQ feedback information of the second transport block.

[0124] For example, the base station retransmits the first transmission block to the terminal on the resources indicated by the third downlink control information for retransmitting the first transmission block; correspondingly, the terminal receives the retransmitted first transmission block from the base station on the resources indicated by the third downlink control information for retransmitting the first transmission block.

[0125] For example, the uplink physical channel carries two bits: the first bit indicates whether the first transport block needs to be retransmitted, and the second bit indicates whether the second transport block was successfully received. For instance, the first bit being "1" indicates that the first transport block needs to be retransmitted; or, the first bit being "0" indicates that the first transport block needs to be retransmitted. For instance, the second bit being "1" indicates that the second transport block was successfully received, and the second bit being "0" indicates that the second transport block was not successfully received; or, the second bit being "0" indicates that the second transport block was successfully received, and the second bit being "1" indicates that the second transport block was not successfully received.

[0126] Figure 6 is a schematic diagram of another example of the data transmission method provided in the embodiments of this application. In this example, a HARQ feedback decoding error occurs for TB1, and the base station mistakenly decodes the NACK fed back by the terminal for TB1 as ACK; the retransmission request for TB1 is sent together with the HARQ feedback information for TB2 (newly transmitted data).

[0127] Steps 1 through 5 can be found in Figure 4, and will not be repeated here.

[0128] Step 6: After the terminal receives the first downlink control information sent by the base station at time t4, the NDI indicated by the first downlink control information flips, indicating that the base station is about to transmit new data. This indicates that the first feedback information sent at time t3 had a decoding error, and the base station mistakenly decoded NACK as ACK. The base station sends TB2 to the terminal on the first downlink control information scheduling resources, and the terminal receives TB2 from the base station accordingly.

[0129] At time t5, the terminal sends a request message and a second feedback message (HARQ feedback message for TB2) to the base station. This request message is used to request a retransmission of TB1. The request message and the second feedback message are carried on the same uplink physical channel. Correspondingly, the base station receives the request message and the second feedback message from the terminal.

[0130] For example, the uplink physical channel carries two bits: the first bit indicates whether TB1 needs to be retransmitted, and the second bit indicates whether TB2 was successfully received. For instance, the first bit being "1" indicates that TB1 needs to be retransmitted; or the first bit being "0" indicates that TB1 needs to be retransmitted.

[0131] Step 7: After receiving the request information from the terminal, the base station learns that a decoding error has occurred in the first downlink control information. At time t6, the base station sends third downlink control information to the terminal. This third downlink control information is used to schedule TB1. This third downlink control information indicates that NDI = 0. Compared to the previous NDI, the current NDI has flipped again. An NDI flip after the request information does not indicate a new transmission, but rather a retransmission of TB1. Correspondingly, the terminal receives the third downlink control information from the base station and receives TB1 from the base station on the resources indicated by the third downlink control information. After receiving the retransmitted TB1, the terminal performs soft-merge decoding with the TB1 buffered in the buffer. In this example, the third control information indicates the resources used for retransmitting TB1.

[0132] Step 8: After the terminal successfully receives TB1 (soft merging and decoding successful) from the base station, the terminal sends an ACK for TB1 to the base station at time t7; correspondingly, the base station receives the ACK for TB1 from the terminal.

[0133] Step 9: If the base station receives an ACK for TB1, and the second feedback information received by the base station in step 6 is NACK, then the base station sends a PDCCH to the terminal at time t8. This PDCCH is used to schedule TB2. The DCI indicator NDI carried by this PDCCH is 1, and compared with the previous NDI, the current NDI has been flipped, indicating that TB2 is being retransmitted. Correspondingly, the terminal receives the PDCCH from the base station and receives TB2 from the base station on the PDSCH corresponding to the PDCCH. After receiving the retransmitted TB2, the terminal performs soft-merging decoding on the retransmitted TB2 and the TB2 buffered in the buffer.

[0134] Step 10: At time t9, the terminal sends HARQ feedback information for TB2 to the base station. It should be noted that, with the uplink physical channel carrying two bits, since the terminal has successfully received TB1, the first bit indicates that TB1 will not be retransmitted.

[0135] Optionally, if the base station receives an ACK for TB1, and the second feedback information received by the base station in step 6 is an ACK, then the PDCCH sent by the base station to the terminal at time t8 is used to schedule the third TB. The DCI carried by the PDCCH indicates that NDI=1. Compared with the previous NDI, the NDI of this time has been flipped, indicating that the third TB has been transmitted.

[0136] Figure 7 is a schematic diagram of another example of the data transmission method provided in the embodiments of this application. In this example, multiple HARQ feedback decoding errors occur for TB1, and the base station mistakenly decodes the NACK feedback from the terminal for TB1 as ACK; the retransmission request for TB1 is sent together with the HARQ feedback information for TB2 (newly transmitted data).

[0137] Step 1: At time t0, the base station sends a PDCCH to the terminal. This PDCCH is used to schedule TB1. The DCI indicator NDI carried by this PDCCH is 0. Compared with the previous NDI, the current NDI has been flipped, indicating that the data in TB1 transmitted this time is newly transmitted data. Correspondingly, the terminal receives the PDCCH from the base station and receives TB1 from the base station on the PDSCH corresponding to the PDCCH.

[0138] Step 2: If the terminal fails to receive TB1 from the base station, the terminal sends a first feedback message to the base station at time t1. This first feedback message is a NACK feedback for TB1. Correspondingly, the base station monitors the terminal's first feedback message.

[0139] Step 3: If a decoding error occurs in the first feedback information, the base station decodes NACK to ACK, assuming the terminal has successfully received TB1. At time t2, the base station sends the first downlink control information to the terminal. This first downlink control information is used to schedule TB2. This first downlink control information indicates that NDI = 1, meaning the NDI has flipped compared to the previous one, indicating that the data in TB2 being transmitted is newly transmitted data. Correspondingly, the terminal receives the first downlink control information from the base station.

[0140] Step 4: After the terminal receives the first downlink control information sent by the base station at time t2, the NDI indicated by the first downlink control information is flipped, indicating that the base station is about to transmit new data. This indicates that the first feedback information sent at time t1 has a decoding error, and the base station mistakenly decodes NACK as ACK. The base station sends TB2 to the terminal on the resources scheduled by the first downlink control information sent at time t2. Correspondingly, the terminal receives TB2 from the base station.

[0141] At time t3, the terminal sends a request message and a second feedback message for TB2 to the base station. The request message is used to request a retransmission of TB1. The request message and the second feedback message are carried on the same uplink physical channel. Correspondingly, the base station receives the request message and the second feedback message from the terminal.

[0142] For example, the uplink physical channel carries two bits: the first bit indicates whether TB1 needs to be retransmitted, and the second bit indicates whether TB2 was successfully received. For instance, the first bit being "1" indicates that TB1 needs to be retransmitted; or the first bit being "0" indicates that TB1 needs to be retransmitted.

[0143] Step 5: After receiving the request information from the terminal, the base station learns that a decoding error has occurred in the first feedback information. At time t4, the base station sends third downlink control information to the terminal. This third downlink control information is used to schedule TB1. This third downlink control information indicates that NDI = 0. Compared with the previous NDI, the current NDI has flipped again. An NDI flip after the request information does not indicate a new transmission, but a retransmission of TB1. Correspondingly, the terminal receives the third downlink control information from the base station and continues to retain TB1 buffered in the buffer. In this example, the third control information indicates the resources used for retransmitting TB1.

[0144] Step 6: If the terminal still fails to receive TB1 from the base station, the terminal sends the first feedback information to the base station at time t5. Correspondingly, the base station monitors the terminal's first feedback information.

[0145] Step 7: If a first feedback information decoding error occurs, the base station decodes NACK to ACK, assuming the terminal has successfully received TB1. At time t6, the base station sends a PDCCH to the terminal. This PDCCH is used to schedule TB2. The DCI indicator NDI carried by this PDCCH is 1. Compared to the previous NDI, the current NDI has been flipped, indicating that the data in TB2 transmitted this time is newly transmitted data. Correspondingly, the terminal receives the PDCCH from the base station.

[0146] Step 8: After the terminal receives the PDCCH sent by the base station at time t6, the DCI carried by the PDCCH is flipped, indicating that the base station is about to transmit new data. This indicates that the first feedback information sent at time t5 has a decoding error, and the base station mistakenly decodes NACK as ACK. The base station sends TB2 to the terminal on the PDSCH scheduled by the PDCCH sent at time t6. Correspondingly, the terminal receives TB2 from the base station.

[0147] At time t7, the terminal sends a request message and a second feedback message for TB2 to the base station. The request message is used to request a retransmission of TB1. The request message and the second feedback message are carried on the same uplink physical channel. Correspondingly, the base station receives the request message and the second feedback message from the terminal.

[0148] Step 9: After receiving the request information from the terminal, the base station learns that a first feedback information decoding error has occurred. At time t8, the base station sends a PDCCH to the terminal. This PDCCH is used to schedule TB1. The DCI indicator NDI carried by this PDCCH is 0. Compared with the previous NDI, the current NDI has flipped again. An NDI flip after the request information does not indicate a new transmission, but rather a retransmission of TB1. Correspondingly, the terminal receives the PDCCH from the base station and receives TB1 from the base station on the corresponding PDSCH. After receiving the retransmitted TB1, the terminal performs soft-merge decoding with the TB1 buffered in the buffer.

[0149] Optionally, after the terminal successfully receives TB1 (soft-merging decoding successful) from the base station, the terminal sends an ACK for TB1 to the base station; correspondingly, the base station receives the ACK for TB1 from the terminal.

[0150] Optionally, after step S210, if the base station receives first feedback information from the terminal, indicating that the terminal failed to receive the first transmission block but the first transmission block has reached the maximum retransmission count, the base station sends first downlink control information to the terminal. This first downlink control information is used to schedule a second transmission block, and the data in the second transmission block is the initial transmission data. In this optional implementation, the base station correctly decodes the first feedback information (NACK for the first transmission block) from the terminal, but the first transmission block has reached the maximum retransmission count.

[0151] For example, after the terminal receives first downlink control information for scheduling a second transport block, the base station uses the resources scheduled by the first downlink control information to send the second transport block to the terminal. The terminal receives the second transport block from the base station according to the first downlink control information. The terminal sends request information and second feedback information to the base station. The request information is used to request retransmission of the first transport block, and the second feedback information indicates whether the second transport block was successfully received. The request information and the second feedback information are carried on the same uplink physical channel. After the base station receives the request information from the terminal for requesting retransmission of the first transport block, since the base station correctly received the first feedback information from the terminal, the first transport block has reached the maximum number of retransmissions at the MAC layer, and the base station abandons retransmission of the first transport block. If the second feedback information indicates that the second transport block was not successfully received, the base station sends fourth downlink control information to the terminal, which is used to schedule the second transport block; correspondingly, the terminal receives the fourth downlink control information from the base station. The base station uses the resources scheduled by the fourth downlink control information to send the retransmitted second transport block to the terminal; correspondingly, the terminal receives the retransmitted second transport block from the base station according to the fourth downlink control information.

[0152] Figure 8 is a schematic diagram of another example of the data transmission method provided in the embodiments of this application. In this example, no HARQ feedback decoding error occurred, and the base station successfully received the NACK for TB1 from the terminal. However, since TB1 reached the maximum number of retransmissions at the MAC layer, the base station abandoned the retransmission of TB1. The retransmission request for TB1 was sent together with the HARQ feedback information for TB2 (newly transmitted data).

[0153] Steps 1 through 5 can be found in Figure 5, and will not be repeated here.

[0154] Step 6: After receiving the first downlink control information sent by the base station at time t4, the terminal believes that the decoding of the first feedback information sent at time t3 has failed because the NDI indicated by the first downlink control information has flipped, indicating that the base station is about to transmit new data. The base station mistakenly decodes NACK as ACK. The base station sends TB2 to the terminal on the resources scheduled by the first downlink control information sent at time t4, and the terminal receives TB2 from the base station.

[0155] At time t5, the terminal sends a request message and a second feedback message for TB2 to the base station. The request message is used to request a retransmission of TB1. The request message and the second feedback message are carried on the same uplink physical channel. Correspondingly, the base station receives the request message and the second feedback message from the terminal.

[0156] For example, the uplink physical channel carries two bits: the first bit indicates whether TB1 needs to be retransmitted, and the second bit indicates whether TB2 was successfully received. For instance, the first bit being "1" indicates that TB1 needs to be retransmitted; or the first bit being "0" indicates that TB1 needs to be retransmitted.

[0157] Step 7: After receiving the request information from the terminal, the base station decides to abandon the retransmission of TB1 because it has received the first feedback information and TB1 has reached the maximum retransmission count of the MAC layer. If the second feedback information for TB2 received by the base station in step 6 is NACK, the base station sends the fourth control information to the terminal at time t6. This fourth control information is used to schedule TB2. The fourth control information indicates that NDI = 1, and compared with the previous NDI, the current NDI has not flipped, indicating that TB2 is being retransmitted. Correspondingly, the terminal receives the fourth control information from the base station and receives TB2 from the base station on the resource scheduled by the fourth control information. After receiving the retransmitted TB2, the terminal performs soft-merging decoding on the retransmitted TB2 and the TB2 buffered in the buffer.

[0158] Figure 9 is a schematic flowchart of another data transmission method 900 provided in an embodiment of this application.

[0159] In step S910, the terminal sends a first feedback message to the base station, indicating that the first transmission block was not successfully received. Correspondingly, the base station monitors the first feedback message from the terminal, and the first feedback message received by the base station indicates whether the first transmission block was successfully received. Other related descriptions can be found in step S210 of Figure 2, and will not be repeated here.

[0160] S920, the base station sends second downlink control information to the terminal, which indicates whether the first transmission block needs to be retransmitted; correspondingly, the terminal receives the second downlink control information from the base station.

[0161] Optionally, when the base station receives the first feedback information, and the received first feedback information indicates that the terminal has successfully received the first transport block, the base station sends second downlink control information to the terminal. In this example, the base station decodes the first feedback information from the terminal incorrectly. The received first feedback information indicates that the terminal has successfully received the first transport block, and the first feedback information sent by the terminal can be understood as a NACK for the first transport block; in other words, the base station decodes the NACK from the terminal for the first transport block incorrectly, mistakenly decoding the NACK fed back by the terminal as ACK.

[0162] For example, when the base station receives the first feedback information and the received first feedback information indicates that the terminal has successfully received the first transport block, based on the channel state information between the base station and the terminal, it is determined that the channel quality between the base station and the terminal is poor and HARQ feedback decoding errors may occur, and then the base station sends the second downlink control information to the terminal.

[0163] S930, the terminal sends a request message to the base station, which requests the retransmission of the first transport block. Correspondingly, the base station receives the request message from the terminal. It should be noted that, since the terminal failed to receive the first transport block, it sends a request message to the base station to request the retransmission of the first transport block.

[0164] Optionally, S940, specifically refer to step S240 in Figure 2, will not be elaborated here.

[0165] In the technical solution provided in this application embodiment, the terminal sends a first feedback message to the base station indicating that the first transport block was not successfully received. If the base station decodes the first feedback message from the terminal incorrectly and considers that the terminal has successfully received the first transport block, the base station sends a second downlink control message to the terminal indicating whether the first transport block needs to be retransmitted. Based on the second downlink control message, the terminal sends a request message to the base station to request the retransmission of the first transport block. This allows the base station to know that the decoding of the first feedback message from the terminal was incorrect and then sends a retransmitted first transport block to the terminal. This avoids retransmitting the first transport block at the RLC layer due to transmission failure, thereby reducing the retransmission latency of the transport block. Furthermore, the terminal can perform soft-merge decoding with the received retransmitted first transport block and the first transport block buffered in the buffer, thereby enhancing decoding reliability.

[0166] Optionally, in S941, after the base station receives the request information from the terminal, and before the base station sends the first retransmission block to the terminal, the base station sends third downlink control information to the terminal, the third downlink control information indicating the resources used for retransmitting the first transmission block. Correspondingly, the terminal receives the third downlink control information from the base station.

[0167] For example, the base station sends the retransmitted first transmission block to the terminal on the resources indicated by the third downlink control information for retransmitting the first transmission block; correspondingly, the terminal receives the retransmitted first transmission block from the base station on the resources indicated by the third downlink control information for retransmitting the first transmission block.

[0168] Optionally, the base station sends configuration information to the terminal, which indicates the time at which the request information should be sent. Correspondingly, the terminal receives the configuration information from the base station; the terminal then sends the request information to the base station at the time indicated by the configuration information. Based on this implementation, sending the request information according to the configuration information avoids the additional transmission overhead caused by dynamically indicating the time of request information transmission.

[0169] For example, the time when the request information is sent is T3, which is the time interval between the time when the second downlink control information is received. This can be understood as the time when the request information is sent after the time when the second downlink control information is received, with an interval of T3. The time when the second downlink control information is received can be either the start time or the end time of receiving the second downlink control information. In this example, the terminal can determine the time when the request information is sent based on the transmission time of the second downlink control information, without needing to dynamically indicate the time when the request information is sent, thereby saving transmission overhead.

[0170] For example, the time when the request information is sent is T4 seconds after the time when the first feedback information is sent. This can be understood as the time when the request information is sent being T4 seconds after the time when the first feedback information is sent. The time when the first feedback information is sent can be either the start time or the end time of sending the first feedback information. In this example, the terminal can determine the time when the request information is sent based on the transmission time of the first feedback information, without needing to dynamically indicate the transmission time of the request information, thereby saving transmission overhead.

[0171] Figures 10A and 10B are schematic diagrams illustrating the timing of request information transmission. In Figure 10A, the timing of request information transmission is the time interval T3 between receiving the second downlink control information, and in Figure 10B, the timing of request information transmission is the time interval T4 between sending the first feedback information.

[0172] Optionally, T3 and T4 are predefined by the protocol or pre-configured to the terminal by the base station via signaling. After receiving the second downlink control information from the base station, the terminal determines the time to send the request information based on the time of receiving the second downlink control information and T3; or, the terminal determines the time to send the request information based on the time of sending the first feedback information to the base station and T2.

[0173] Figure 11 is a schematic diagram of another example of the data transmission method provided in the embodiments of this application. In this example, a HARQ feedback decoding error occurs, and the base station mistakenly decodes the NACK for TB1 fed back by the terminal as ACK.

[0174] Steps 1 through 4 can be found in Figure 4, and will not be repeated here.

[0175] Step 5: If a first feedback information decoding error occurs, the base station decodes NACK into ACK. Based on the channel state information between the base station and the terminal, the base station determines that the channel quality between the base station and the terminal is poor and a HARQ feedback decoding error may occur. Then, the base station sends a second downlink control information to the terminal at time t4. The second downlink control information indicates whether TB1 needs to be retransmitted. Correspondingly, the terminal receives the second downlink control information from the base station.

[0176] Step 6: If the terminal receives the second downlink control information from the base station, and since the terminal has not successfully received TB1, the terminal sends a request message to the base station at time t5. This request message is used to request the retransmission of TB1. Correspondingly, the base station receives the request message from the terminal.

[0177] Optionally, the base station sends configuration information to the terminal, which indicates the time (t5) at which the request information is sent. Correspondingly, the terminal receives the configuration information from the base station; at the time indicated by the configuration information, the terminal sends the request information to the base station.

[0178] For example, the time when the request information is sent is the time interval T3 between the time when the second downlink control information is received.

[0179] For example, the time when the request information is sent is the time interval T4 between the time when the first feedback information is sent.

[0180] Step 7: After receiving the request information from the terminal, the base station sends third downlink control information to the terminal at time t6. This third downlink control information is used to schedule TB1. The third downlink control information indicates that NDI = 0, meaning that the NDI has not flipped compared to the previous NDI, indicating that TB1 is being retransmitted. Correspondingly, the terminal receives the third downlink control information from the base station and receives the retransmitted TB1 from the base station on the resources scheduled by the third downlink control information. After receiving the retransmitted TB1, the terminal performs soft-merging decoding with the TB1 buffered in the buffer.

[0181] Optionally, after step S910, if the base station receives first feedback information from the terminal, indicating that the terminal failed to receive the first transport block but the first transport block has reached the maximum retransmission count of the MAC layer, the base station sends fourth downlink control information to the terminal. This fourth downlink control information is used to schedule the second transport block. Correspondingly, the terminal receives the fourth downlink control information from the base station. The base station uses the resources scheduled by the fourth downlink control information to send the second transport block to the terminal. Correspondingly, the terminal receives the second transport block from the base station according to the fourth downlink control information. Optionally, the fourth downlink control information is also used to instruct the terminal to clear the buffer / not retransmit the first transport block. Correspondingly, the terminal receives the fourth downlink control information from the base station and clears the buffer according to the fourth downlink control information.

[0182] For example, after the base station receives the first feedback information from the terminal, the received first feedback information indicates that the terminal failed to receive the first transport block, but the first transport block has reached the maximum retransmission count of the MAC layer. The base station abandons retransmitting the first transport block, and the base station sends a fifth downlink control message to the terminal. This fifth downlink control message instructs the terminal to clear the buffer / not retransmit the first transport block. Correspondingly, the terminal receives the fifth downlink control message from the base station and clears the buffer according to the fifth downlink control message. The base station sends a fourth downlink control message to the terminal, which is used to schedule the second transport block. Correspondingly, the terminal receives the fourth downlink control message from the base station. The base station uses the resources scheduled by the fourth downlink control message to send the second transport block to the terminal. Correspondingly, the terminal receives the second transport block from the base station according to the fourth downlink control message.

[0183] For example, the first downlink control information, the second downlink control information, the third downlink control information, the fourth downlink control information, or the fifth downlink control information in the embodiments of this application are information carried on the PDCCH.

[0184] Figure 12 is a schematic diagram of another example of the data transmission method provided in the embodiments of this application. In this example, no HARQ feedback decoding error occurred, and the base station successfully received the NACK for TB1 from the terminal. However, since TB1 reached the maximum number of retransmissions at the MAC layer, the base station abandoned the retransmission of TB1.

[0185] Steps 1 through 4 can be found in Figure 4, and will not be repeated here.

[0186] Step 5: The base station successfully receives the first feedback information (no HARQ feedback decoding error occurred), but because TB1 has reached the maximum number of retransmissions at the MAC layer, the base station abandons the retransmission of TB1. At time t4, the base station sends the fifth downlink control information to the terminal, which instructs the terminal to clear the buffer / not retransmit TB1; correspondingly, the terminal receives the fifth downlink control information from the base station and clears the buffer according to the fifth downlink control information.

[0187] Step 6: At time t5, the base station sends a fourth downlink control message to the terminal. This fourth downlink control message is used to schedule TB2. The fourth downlink control message indicates that NDI = 1, meaning that the NDI has been flipped compared to the previous one, indicating that the data in TB2 being transmitted is newly transmitted data. Correspondingly, the terminal receives the fourth downlink control message from the base station and receives TB2 from the base station on the PDSCH corresponding to this fourth downlink control message. After receiving the newly transmitted TB2, the terminal clears TB1 from the buffer and decodes TB2.

[0188] Optionally, the base station does not send the fifth downlink control information at time t4, but directly sends the fourth downlink control information for scheduling TB2 to the terminal after step 4. Optionally, the fourth downlink control information is also used to instruct the terminal to clear the buffer / not retransmit TB1; correspondingly, the terminal clears TB1 in the buffer according to the fourth downlink control information.

[0189] It is understood that, in order to achieve the functions in the above embodiments, the base station and terminal include hardware structures and / or software modules corresponding to perform each function. Those skilled in the art should readily recognize that, based on the units and method steps described in conjunction with the embodiments disclosed in this application, this application can be implemented in hardware or a combination of hardware and computer software. Whether a function is executed in hardware or by computer software driving hardware depends on the specific application scenario and design constraints of the technical solution.

[0190] The data transmission method provided in the embodiments of this application has been described above. The execution subject for performing the above data transmission method will be described below.

[0191] Figures 13 and 14 are schematic diagrams of possible communication devices provided in the embodiments of this application. These communication devices can be used to implement the functions of the terminal or network device in the above method embodiments, and thus can also achieve the beneficial effects of the above method embodiments. In the embodiments of this application, the communication device can be the terminal 120 shown in Figure 1, the base station 110 shown in Figure 1, or a module (such as a chip) applied to the terminal or base station.

[0192] As shown in Figure 13, the communication device 1300 includes a transceiver module 1310; optionally, the communication device 1300 further includes a processing module 1320. The communication device 1300 is used to implement the functions of a terminal or network device in the method embodiments shown in Figure 2 or Figure 9. When the communication device 1300 is used to implement the functions of a terminal in the method embodiments shown in Figure 2 or Figure 9:

[0193] The transceiver module 1310 is used to send first feedback information to the network device, wherein the first feedback information indicates that the first transmission block was not successfully received;

[0194] The transceiver module 1310 is further configured to receive first downlink control information from the network device, the first downlink control information being used to schedule a second transmission block, the data in the second transmission block being initial transmission data; or, to receive second downlink control information from the network device, the second downlink control information indicating whether the first transmission block needs to be retransmitted.

[0195] The transceiver module 1310 is further configured to send a request message to the network device, the request message being used to request the retransmission of the first transmission block.

[0196] Optionally, the processing module 1320 is used to determine that the first transmission block was not successfully received.

[0197] Optionally, the transceiver module 1310 is further configured to receive third downlink control information from the network device, the third downlink control information indicating retransmission of the first transport block and / or resources for retransmission of the first transport block.

[0198] Optionally, the transceiver module 1310 is further configured to receive the first transmission block of the retransmission from the network device on the resource indicated by the first downlink control information.

[0199] Optionally, the transceiver module 1310 is further configured to receive configuration information from the network device, the configuration information indicating the time of sending the request information; specifically, the transceiver module 1310 is configured to send the request information to the network device at the time of sending.

[0200] Optionally, before sending the request information to the network device, the transceiver module 1310 is further configured to receive the second transport block from the network device according to the first downlink control information; specifically, the transceiver module 1310 is configured to send the request information and the second feedback information to the network device, wherein the second feedback information indicates whether the second transport block has been successfully received, and the request information and the second feedback information are carried on the same uplink physical channel.

[0201] When the communication device 1300 is used to implement the functions of the network device in the method embodiment shown in Figure 2 or Figure 9:

[0202] The transceiver module 1310 is used to monitor first feedback information from the terminal, wherein the first feedback information indicates whether the first transmission block has been successfully received;

[0203] The transceiver module 1310 is further configured to send first downlink control information to the terminal, the first downlink control information being used to schedule a second transmission block, the data in the second transmission block being initial transmission data; or, send second downlink control information to the terminal, the second downlink control information indicating whether the first transmission block needs to be retransmitted.

[0204] The transceiver module 1310 is further configured to receive request information from the terminal, the request information being used to request retransmission of the first transmission block.

[0205] Optionally, the transceiver module 1310 is specifically configured to, upon receiving the first feedback information and the first feedback information indicating that the terminal has successfully received the first transmission block, send the first downlink control information to the terminal, or send the second downlink control information to the terminal.

[0206] Optionally, the processing module 1320 is configured to decode (CRC check) the first feedback information from the terminal and determine that the first feedback information indicates that the terminal has successfully received the first transmission block.

[0207] Optionally, the transceiver module 1310 is further configured to send third downlink control information to the terminal, the third downlink control information indicating retransmission of the first transport block and / or resources for retransmission of the first transport block.

[0208] Optionally, the transceiver module 1310 is further configured to, when the third downlink control information indicates a retransmission of the first transmission block, send the retransmitted first transmission block to the terminal on the resource indicated by the first downlink control information.

[0209] Optionally, the transceiver module 1310 is further configured to send configuration information to the terminal, wherein the configuration information indicates the time at which the request information is sent.

[0210] Optionally, before receiving the request information from the terminal, the transceiver module 1310 is further configured to send the second transmission block to the terminal;

[0211] The transceiver module 1310 is specifically used to receive the request information and the second feedback information from the terminal, wherein the second feedback information indicates whether the second transmission block has been successfully received, and the request information and the second feedback information are carried on the same uplink physical channel.

[0212] Optionally, the transceiver module 1310 is specifically configured to send the first downlink control information to the terminal when it receives the first feedback information, which indicates that the terminal has not successfully received the first transmission block, but the first transmission block has reached the maximum number of retransmissions.

[0213] Optionally, the transceiver module 1310 is further configured to send the second transmission block to the terminal.

[0214] For a more detailed description of the transceiver module 1310 and the processing module 1320, please refer to the relevant descriptions in the method embodiments shown in Figure 2 or Figure 9.

[0215] As shown in Figure 14, the communication device 1400 can be applied to the aforementioned terminal or network device. The communication device 1400 includes a processor 1410, which implements the data transmission method provided in this application embodiment through logic circuits or executing code instructions.

[0216] Optionally, the communication device 1400 may also include interface circuitry 1420. Processor 1410 and interface circuitry 1420 are coupled to each other. It is understood that interface circuitry 1420 may be a transceiver or an input / output interface.

[0217] Optionally, the communication device 1400 may also include a memory 1430 for storing instructions executed by the processor 1410, or storing input data required by the processor 1410 to execute instructions, or storing data generated after the processor 1410 executes instructions.

[0218] The aforementioned processor 1410 may be an integrated circuit chip with signal processing capabilities. In implementation, the steps of the above method embodiments can be completed by integrated logic circuits in the processor's hardware or by software instructions. The aforementioned processor may be a general-purpose processor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA), or other programmable logic devices, discrete gate or transistor logic devices, or discrete hardware components. It can implement or execute the methods, steps, and logic block diagrams disclosed in the embodiments of this application. The general-purpose processor may be a microprocessor or any conventional processor. The steps of the methods disclosed in the embodiments of this application can be directly embodied in the execution of a hardware decoding processor, or executed by a combination of hardware and software modules in the decoding processor. The software modules may reside in random access memory, flash memory, read-only memory, programmable read-only memory, electrically erasable programmable memory, registers, or other mature storage media in the art. This storage medium is located in memory; the processor reads information from the memory and, in conjunction with its hardware, completes the steps of the above method.

[0219] This application also provides a communication system, including a terminal and a network device in the data transmission method provided in this application.

[0220] This application also provides a computer-readable storage medium storing a computer program for implementing the methods in the above-described method embodiments. When the computer program is run on a computer, the computer can implement the methods in the above-described method embodiments.

[0221] This application also provides a computer program product, which includes a computer program that, when run on a computer, causes the methods in the above method embodiments to be executed.

[0222] This application also provides a chip, including a processor connected to a memory for storing computer programs, and the processor for executing the computer programs stored in the memory, so that the chip performs the methods described in the above method embodiments.

[0223] It should be understood that, in the embodiments of this application, for a technical feature, the technical features in that technical feature are distinguished by "first", "second" and "third", and there is no order of precedence or size among the technical features described by "first", "second" and "third".

[0224] Furthermore, the term "and / or" in this application is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone. Additionally, the character " / " in this document generally indicates that the preceding and following related objects have an "or" relationship. The term "at least one" in this application can represent "one" and "two or more." For example, A, B, and C can represent: A existing alone, B existing alone, C existing alone, A and B existing simultaneously, A and C existing simultaneously, C and B existing simultaneously, and A, B, and C existing simultaneously.

[0225] In the embodiments of this application, "send" and "receive" indicate the direction of signal transmission. For example, "send information to XX" can be understood as the destination of the information being XX, which may include direct transmission via the air interface or indirect transmission via the air interface by other units or modules. "Receive information from YY" can be understood as the source of the information being YY, which may include direct reception from YY via the air interface or indirect reception from YY via the air interface by other units or modules. "Send" can also be understood as the "output" of the chip interface, and "receive" can also be understood as the "input" of the chip interface.

[0226] In other words, sending and receiving can occur between devices, such as between access network devices and terminals, or within a device, such as between components, modules, chips, software modules, or hardware modules within the device via buses, wiring, or interfaces.

[0227] It is understandable that information may undergo necessary processing, such as encoding and modulation, between the source and destination, but the destination can understand the valid information from the source. Similar statements in this application can be interpreted in a similar way and will not be elaborated further.

[0228] In the embodiments of this application, "instruction" can include direct and indirect instructions, as well as explicit and implicit instructions. The information indicated by a certain piece of information (hereinafter referred to as instruction information) is called the information to be instructed. In specific implementation, there are many ways to indicate the information to be instructed, such as, but not limited to, directly indicating the information to be instructed, such as the information to be instructed itself or its index. It can also indirectly indicate the information to be instructed by indicating other information, where there is an association between the other information and the information to be instructed; or it can only indicate a part of the information to be instructed, while the other parts are known or pre-agreed upon. For example, the instruction can be implemented by using a pre-agreed (e.g., protocol predefined) arrangement of various information, thereby reducing the instruction overhead to a certain extent. This application does not limit the specific method of instruction. It is understood that for the sending end of the instruction information, the instruction information can be used to indicate the information to be instructed; for the receiving end of the instruction information, the instruction information can be used to determine the information to be instructed.

[0229] In this application, unless otherwise specified, the same or similar parts between the various embodiments can be referred to each other. In the various embodiments of this application, and in the various implementation methods / methods / implementations within each embodiment, unless otherwise specified or logically conflicting, the terminology and / or descriptions between different embodiments and between the various implementation methods / methods / implementations within each embodiment are consistent and can be mutually referenced. The technical features in different embodiments and the various implementation methods / methods / implementations within each embodiment can be combined according to their inherent logical relationships to form new embodiments, implementation methods, methods, or implementation approaches. The embodiments described below do not constitute a limitation on the scope of protection of this application.

[0230] Those skilled in the art will recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0231] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working processes of the systems, devices, and units described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here.

[0232] In the several embodiments provided in this application, it should be understood that the disclosed systems, apparatuses, and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for instance, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through some interfaces; the indirect coupling or communication connection between apparatuses or units may be electrical, mechanical, or other forms.

[0233] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0234] In addition, the functional units in the various embodiments of this application can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit.

[0235] If the aforementioned functions are implemented as software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or a portion of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of this application. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

Claims

1. A method for data transmission, characterized in that, include: Send a first feedback message to the network device, the first feedback message indicating that the first transport block was not successfully received; Receive first downlink control information from the network device, the first downlink control information being used to schedule a second transport block, the data in the second transport block being initial transmission data; or, receive second downlink control information from the network device, the second downlink control information indicating whether the first transport block needs to be retransmitted. Send a request message to the network device, the request message being used to request the retransmission of the first transport block.

2. The method according to claim 1, characterized in that, Also includes: Receive third downlink control information from the network device, the third downlink control information indicating retransmission of the first transport block and / or resources for retransmission of the first transport block.

3. The method according to claim 2, characterized in that, In the case where the third downlink control information indicates a retransmission of the first transport block, the method further includes: On the resource indicated by the first downlink control information, the first transport block retransmitted from the network device is received.

4. The method according to claim 1 or 2, characterized in that, It also includes: receiving configuration information from the network device, wherein the configuration information indicates the time at which the request information was sent; Sending the request information to the network device includes: sending the request information to the network device at the sending time.

5. The method according to claim 4, characterized in that, The time at which the request information is sent is the time interval T1 between the time interval of receiving the first downlink control information, or the time interval T2 between the time interval of the time domain resource indicated by the first downlink control information, wherein the time at which the request information is sent is earlier than the start time.

6. The method according to claim 4, characterized in that, The time at which the request information is sent is the time interval T3 between the time interval of receiving the second downlink control information.

7. The method according to claim 1 or 2, characterized in that, Before sending the request information to the network device, the method further includes: receiving the second transport block from the network device according to the first downlink control information; Sending request information to the network device includes: sending the request information and second feedback information to the network device, wherein the second feedback information indicates whether the second transport block was successfully received, and the request information and the second feedback information are carried on the same uplink physical channel.

8. A method for data transmission, characterized in that, include: Monitor the first feedback information from the terminal, which indicates whether the first transmission block has been successfully received; Send a first downlink control message to the terminal, the first downlink control message being used to schedule a second transport block, the data in the second transport block being the initial transmission data; or send a second downlink control message to the terminal, the second downlink control message indicating whether the first transport block needs to be retransmitted. The system receives a request from the terminal, the request being used to request the retransmission of the first transport block.

9. The method according to claim 8, characterized in that, Sending the first downlink control information to the terminal, or sending the second downlink control information to the terminal, includes: Upon receiving the first feedback information, and if the first feedback information indicates that the terminal has successfully received the first transport block, the system sends the first downlink control information to the terminal, or sends the second downlink control information to the terminal.

10. The method according to claim 8 or 9, characterized in that, Also includes: A third downlink control message is sent to the terminal, the third downlink control message indicating the retransmission of the first transport block and / or the resources used for retransmitting the first transport block.

11. The method according to claim 10, characterized in that, In the case where the third downlink control information indicates a retransmission of the first transport block, the method further includes: On the resource indicated by the first downlink control information, the first transmission block that is retransmitted is sent to the terminal.

12. The method according to any one of claims 8 to 10, characterized in that, Also includes: Configuration information is sent to the terminal, wherein the configuration information indicates the time at which the request information is sent.

13. The method according to claim 12, characterized in that, The time at which the request information is sent is the time interval T1 between the time interval of receiving the first downlink control information, or the time interval T2 between the time interval of the time domain resource indicated by the first downlink control information, wherein the time at which the request information is sent is earlier than the start time.

14. The method according to claim 12, characterized in that, The time at which the request information is sent is the time interval T3 between the time interval of receiving the second downlink control information.

15. The method according to any one of claims 8 to 10, characterized in that, Before receiving the request information from the terminal, the method further includes: sending the second transmission block to the terminal; Receiving request information from the terminal includes: receiving request information and second feedback information from the terminal, wherein the second feedback information indicates whether the second transport block was successfully received, and the request information and the second feedback information are carried on the same uplink physical channel.

16. The method according to claim 8, characterized in that, Sending the first downlink control information to the terminal includes: Upon receiving the first feedback information, which indicates that the terminal has not successfully received the first transmission block, but the first transmission block has reached the maximum number of retransmissions, the first downlink control information is sent to the terminal.

17. The method according to claim 16, characterized in that, Also includes: The second transmission block is sent to the terminal.

18. A communication device, characterized in that, It includes a module for performing the method as described in any one of claims 1 to 7, or a module for performing the method as described in any one of claims 8 to 17.

19. A computer-readable storage medium, characterized in that, include: The computer-readable medium stores a computer program; When the computer program is run by the processor, the method of any one of claims 1 to 17 is performed.

20. A computer program product, characterized in that, Includes a computer program, which, when executed, causes the method as described in any one of claims 1 to 17 to be performed.

Images