Data Transmission Method and Device

Abstract

The present application provides a data transmission method and apparatus, which are used to solve the problem of large signaling overhead in multicast transmission control. The method includes: receiving first multicast data transmitted based on semi-persistent scheduling (SPS) of multicast; receiving first downlink control information (DCI), where the first DCI is masked by a configured scheduling radio network temporary identity (CS-RNTI); and receiving first data according to the first DCI, where the first data is retransmitted data of the first multicast data.

Description

Technical Field

[0001] Embodiments of the present application relate to the field of communication technologies, and in particular, to a data transmission method and apparatus. Background Art

[0002] In a 4G network or a 5G network, a base station can send data to a terminal in a multicast manner or a unicast manner. The multicast manner can save downlink resources compared with the unicast manner.

[0003] Currently, multicast transmission usually adopts dynamic scheduling. For example, before each physical downlink shared channel (PDSCH) is sent, a physical downlink control channel (PDCCH) needs to be sent to schedule the PDSCH, and the downlink data is carried on the PDSCH. In this manner, the overhead of control signaling is large, resulting in low data transmission efficiency. Summary of the Invention

[0004] Embodiments of the present application provide a data transmission method and apparatus, aiming to reduce signaling overhead and improve data transmission efficiency.

[0005] In a first aspect, an embodiment of the present application provides a data transmission method, including: receiving first multicast data transmitted based on semi-persistent scheduling (SPS) of multicast; receiving first downlink control information (DCI), where the first DCI is masked by a configured scheduling radio network temporary identity (CS-RNTI); and receiving first data according to the first DCI, where the first data is retransmitted data of the first multicast data.

[0006] In the embodiments of the present application, multicast data transmission is performed using semi-persistent scheduling, and there is no need to send scheduling information, that is, DCI, before each multicast data is sent, which can reduce the overhead of control signaling; and when retransmitting data for an individual terminal device, the foregoing multicast data is retransmitted to the terminal device in a unicast manner instead of scheduling the retransmission of data in a multicast manner, which can further save the occupancy of downlink resources and improve data transmission efficiency.

[0007] In an optional implementation manner, the method further includes: receiving a second DCI masked by a group-configured scheduling radio network temporary identity (G-CS-RNTI), where the second DCI is used to activate the semi-persistent scheduling (SPS) transmission of the multicast.

[0008] In an alternative implementation, the method further includes: receiving a third DCI masked by a group radio network temporary identity (G-RNTI), where the third DCI is used to activate the semi-persistent scheduling (SPS) transmission of the multicast. A first indication information included in the third DCI has a value of a first value. Here, the value of the first indication information includes a first value or a second value. The first value is used to indicate the SPS transmission of the multicast, and the second value is used to indicate the dynamic scheduling transmission of the multicast. By defining a manner in the DCI to indicate semi-persistent scheduling or dynamic scheduling, it is possible to use the G-RNTI to implement dynamic scheduling of multicast data or semi-persistent scheduling of multicast data, expanding the application scenario of the G-RNTI, saving the resources for blind detection on the terminal device side, and also reducing the control signaling overhead during the downlink data scheduling of the multicast.

[0009] In an alternative implementation, the third DCI does not include information for indicating whether the third DCI is used to schedule uplink transmission or downlink transmission.

[0010] In an alternative implementation, the new data indication (NDI) value in the first DCI is 1; the NDI value in the second DCI is 0; the NDI value in the third DCI is 0. The NDI in the DCI can be used to distinguish whether the scheduled data is initial transmission data or retransmission data.

[0011] In an alternative implementation, the method further includes: receiving a fourth DCI masked by a group radio network temporary identity (G-RNTI), where the fourth DCI is used to deactivate the SPS transmission of the multicast; or receiving a fourth DCI masked by a group configured scheduling radio network temporary identity (G-CS-RNTI), where the fourth DCI is used to deactivate the SPS transmission of the multicast. It can be understood that the G-RNTI corresponding to the fourth DCI and the G-RNTI corresponding to the third DCI may be the same or different; similarly, the G-CS-RNTI corresponding to the fourth DCI and the G-CS-RNTI corresponding to the second DCI may be the same or different.

[0012] In a second aspect, an embodiment of the present application provides a data transmission method, which can be applied to a network device and includes:

[0013] Send the first multicast data for transmitting semi-persistent scheduling (SPS) based on multicast. It can be understood that, generally, this first multicast data is sent to multiple terminal devices. Send the first downlink control information (DCI) to a single terminal device among the multiple terminal devices, where the first DCI is masked by a configured scheduling radio network temporary identity (CS-RNTI), and the first DCI is used to schedule the first data, and the first data is the retransmission data of the first multicast data; wherein, the single terminal device refers to one of the terminal devices that have not successfully received the first multicast data, or the single terminal device refers to one of the terminal devices for which the network-side device has not received an affirmative feedback for the first multicast data, or the single terminal device refers to one of the terminal devices for which the network-side device has received a negative feedback for the first multicast data.

[0014] In the embodiments of the present application, when using semi-persistent scheduling for multicast data transmission, there is no need to send scheduling information, i.e., DCI, before sending multicast data each time, which can reduce the overhead of control signaling; and when retransmitting data to an individual terminal device, the foregoing multicast data is retransmitted to the terminal device in a unicast manner instead of scheduling the retransmission of data in a multicast manner, which can further save the occupancy of downlink resources and improve the data transmission efficiency.

[0015] In an optional implementation manner, the method further includes: sending a second DCI masked by a group configuration scheduling radio network temporary identity (G-CS-RNTI), where the second DCI is used to activate the semi-persistent scheduling (SPS) transmission of the multicast.

[0016] In an optional implementation manner, the method further includes: sending a third DCI masked by a group radio network temporary identity (G-RNTI), where the third DCI is used to activate the semi-persistent scheduling (SPS) transmission of the multicast, and a first indication information included in the third DCI takes a first value, where the value of the first indication information includes a first value or a second value, the first value is used to indicate the semi-persistent scheduling (SPS) transmission of the multicast, and the second value is used to indicate the dynamic scheduling transmission of the multicast. By defining a method in the DCI for indicating semi-persistent scheduling or dynamic scheduling, it is possible to use the G-RNTI to implement dynamic scheduling of multicast data or semi-persistent scheduling of multicast data, expand the application scenario of the G-RNTI, save the resources of blind detection on the terminal device side, and at the same time reduce the control signaling overhead during the downlink data scheduling of the multicast.

[0017] In an optional implementation manner, the third DCI does not include information for indicating whether the third DCI is used to schedule uplink transmission or downlink transmission.

[0018] In an alternative implementation, the new data indication NDI value in the first DCI is 1; the new data indication NDI value in the second DCI is 0; the new data indication NDI value in the third DCI is 0. The NDI in the DCI can be used to distinguish whether the scheduled data is initial transmission data or retransmission data.

[0019] In an alternative implementation, the method further includes: sending a fourth DCI masked by a group radio network temporary identity G-RNTI, where the fourth DCI is used to deactivate the semi-persistent scheduling SPS transmission of the multicast; or, sending a fourth DCI masked by a group configured scheduling radio network temporary identity G-CS-RNTI, where the fourth DCI is used to deactivate the semi-persistent scheduling SPS transmission of the multicast.

[0020] In a third aspect, an embodiment of the present application provides a data transmission apparatus, including: a communication unit, configured to receive first multicast data for semi-persistent scheduling SPS transmission based on multicast; the communication unit is further configured to receive a first downlink control information DCI, where the first DCI is masked by a configured scheduling radio network temporary identity CS-RNTI; a processing unit, configured to receive first data through the communication unit according to the first DCI, where the first data is retransmission data of the first multicast data. Optionally, before the communication unit receives the first DCI, the processing unit is further configured to determine that the reception of the first multicast data fails, and send a feedback message such as NACK, where the feedback message is used to indicate that the reception of the first multicast data fails.

[0021] In an alternative implementation, the communication unit is further configured to: receive a second DCI masked by a group configured scheduling radio network temporary identity G-CS-RNTI, where the second DCI is used to activate the semi-persistent scheduling SPS transmission of the multicast.

[0022] In an alternative implementation, the communication unit is further configured to: receive a third DCI masked by a group radio network temporary identity G-RNTI, where the third DCI is used to activate the semi-persistent scheduling SPS transmission of the multicast, and a first indication information included in the third DCI takes a first value, where the first indication information takes values including a first value or a second value, the first value is used to indicate the semi-persistent scheduling SPS transmission of the multicast, and the second value is used to indicate the dynamic scheduling transmission of the multicast.

[0023] In an alternative implementation, the third DCI does not include information for indicating whether the third DCI is used to schedule uplink transmission or downlink transmission.

[0024] In an alternative implementation, the new data indication NDI value in the first DCI is 1; the new data indication NDI value in the second DCI is 0; the new data indication NDI value in the third DCI is 0.

[0025] In an alternative implementation, the communication module is further configured to: receive a fourth DCI masked by a group radio network temporary identifier G-RNTI, where the fourth DCI is used to deactivate the semi-persistent scheduling SPS transmission of the multicast; or receive a fourth DCI masked by a group configured scheduling radio network temporary identifier G-CS-RNTI, where the fourth DCI is used to deactivate the semi-persistent scheduling SPS transmission of the multicast.

[0026] In a fourth aspect, an embodiment of the present application provides a data transmission device, including: a processing unit configured to generate first multicast data for semi-persistent scheduling SPS transmission based on multicast; a communication unit configured to send the first multicast data; the communication unit is further configured to send a first downlink control information DCI, where the first DCI is masked by a configured scheduling radio network temporary identifier CS-RNTI, and the first DCI is used to schedule first data, and the first data is retransmission data of the first multicast data.

[0027] In the embodiments of the present application, semi-persistent scheduling is adopted during multicast transmission, and there is no need to send scheduling information, that is, DCI, before sending multicast data each time, which can reduce the overhead of control signaling; and when retransmitting data to individual terminal devices, the foregoing multicast data is retransmitted to the terminal device in a unicast manner instead of scheduling the retransmission of data in a multicast manner, which can further save the occupation of downlink resources and improve the data transmission efficiency.

[0028] In an alternative implementation, the communication unit is further configured to: send a second DCI masked by a group configured scheduling radio network temporary identifier G-CS-RNTI, where the second DCI is used to activate the semi-persistent scheduling SPS transmission of the multicast.

[0029] In an alternative implementation, the communication unit is further configured to: send a third DCI masked by a group radio network temporary identifier G-RNTI, where the third DCI is used to activate the semi-persistent scheduling SPS transmission of the multicast, and a first indication information value included in the third DCI takes a first value, where the first indication information value includes a first value or a second value, the first value is used to indicate the semi-persistent scheduling SPS transmission of the multicast, and the second value is used to indicate the dynamic scheduling transmission of the multicast.

[0030] In an alternative implementation, the third DCI does not include information for indicating whether the third DCI is used to schedule uplink transmission or downlink transmission.

[0031] In an alternative implementation, the new data indication NDI value in the first DCI is 1; the new data indication NDI value in the second DCI is 0; the new data indication NDI value in the third DCI is 0.

[0032] In an alternative implementation, the communication unit is further configured to: send a fourth DCI masked by a group radio network temporary identity G-RNTI, where the fourth DCI is used to deactivate the multicast semi-persistent scheduling SPS transmission; or, send a fourth DCI masked by a group configured scheduling radio network temporary identity G-CS-RNTI, where the fourth DCI is used to deactivate the multicast semi-persistent scheduling SPS transmission.

[0033] In a fifth aspect, an embodiment of the present application provides a communication device, including a processor, the processor is coupled to a memory, the memory is used to store computer programs or instructions, and the processor is used to execute the computer programs or instructions to perform the implementation methods of the first aspect or the second aspect above. The memory may be located inside the device or outside the device. The number of processors is one or more.

[0034] In a sixth aspect, an embodiment of the present application provides a communication device, including: a logic circuit and an input / output interface; the input / output interface is used to input first multicast data for multicast semi-persistent scheduling SPS transmission; the input / output interface is further used to input a first downlink control information DCI, where the first DCI is masked by a configured scheduling radio network temporary identity CS-RNTI; the logic circuit is used to obtain first data through the input / output interface according to the first DCI, and the first data is retransmitted data of the first multicast data. Optionally, before the input / output interface inputs the first DCI, the logic circuit is further used to determine that the reception of the first multicast data fails, and output feedback information such as NACK, where the feedback information is used to indicate that the reception of the first multicast data fails.

[0035] In a seventh aspect, an embodiment of the present application provides a communication device, including: a logic circuit and an input / output interface; the logic circuit is used to generate first multicast data for multicast semi-persistent scheduling SPS transmission; the input / output interface is used to output the first multicast data; the input / output interface is further used to output a first downlink control information DCI, where the first DCI is masked by a configured scheduling radio network temporary identity CS-RNTI, and the first DCI is used to schedule first data, and the first data is retransmitted data of the first multicast data.

[0036] In an eighth aspect, the present application provides a communication device, including: a processor and an interface circuit, the interface circuit is used to communicate with other devices, and the processor is used to perform the implementation methods of the first aspect or the second aspect above.

[0037] In a ninth aspect, the present application provides a communication system, including: a terminal device configured to execute the implementation methods of the first aspect above, and a network device configured to execute the implementation methods of the second aspect above.

[0038] In a tenth aspect, the present application further provides a chip system, including: a processor configured to execute the implementation methods of the first aspect or the second aspect above.

[0039] In an eleventh aspect, the present application further provides a computing program product, including computer-executable instructions, which, when running on a computer, cause the implementation methods of the first aspect or the second aspect above to be executed.

[0040] In a twelfth aspect, the present application further provides a computer-readable storage medium, in which a computer program or instructions are stored, and when the instructions run on a computer, the implementation methods of the first aspect or the second aspect above are implemented.

[0041] For the technical effects that can be achieved in the fifth aspect to the tenth aspect above, please refer to the technical effects that can be brought by the corresponding technical solutions in the first aspect to the second aspect above, and will not be repeated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 FIG. is a schematic diagram of a communication system architecture provided by an embodiment of the present application;

[0043] Figure 2 FIG. is a schematic diagram of data scheduling for multicast-based SPS transmission provided by an embodiment of the present application;

[0044] Figure 3 FIG. is a schematic diagram of a retransmission scheduling mechanism for unicast provided by an embodiment of the present application;

[0045] Figure 4 FIG. is a schematic diagram of deactivating multicast SPS transmission provided by an embodiment of the present application;

[0046] Figure 5 FIG. is another schematic diagram of data scheduling for multicast-based SPS transmission provided by an embodiment of the present application;

[0047] Figure 6 FIG. is another schematic diagram of deactivating multicast SPS transmission provided by an embodiment of the present application;

[0048] Figure 7 FIG. is a schematic diagram of a process of a data transmission method provided by an embodiment of the present application;

[0049] Figure 8 FIG. is a schematic diagram of the structure of a data transmission device provided by an embodiment of the present application;

[0050] Figure 9 A schematic structural diagram of a communication device provided by an embodiment of the present application;

[0051] Figure 10 A schematic structural diagram of another communication device provided by an embodiment of the present application. Detailed implementation manners

[0052] The communication method and device provided by the embodiments of the present application can be applied to various communication systems, especially the system of harmonized communication and sensing (HCS). The communication in this system includes but is not limited to: Long Term Evolution (LTE) system, 5th generation (5G) system, New Radio (NR) system, Wireless-Fidelity (WiFi) system, other wireless communication systems related to the 3rd Generation Partnership Project (3GPP), or future possible wireless communication systems, etc.

[0053] The following explanations are provided for some terms used in the embodiments of the present application to facilitate the understanding of those skilled in the art:

[0054] (1) Network device

[0055] The network device can communicate with the terminal device and provide wireless access services for the terminal device. The network device can also be called a base station device or a base station. Among them, the base station may have various forms, such as macro base stations, micro base stations, relay stations, and access points, etc. Exemplarily, the network device involved in the following embodiments of the present application can be a base station in New Radio (NR), and among them, the base station in 5G NR can also be called a Transmission Reception Point (TRP) or a Next Generation Node B (gNB); the network device involved in the following embodiments of the present application can also be a Node B (NB) in a Wideband Code Division Multiple Access (WCDMA) system; the network device involved in the following embodiments of the present application can also be an Evolutional Node B (eNB or eNodeB) in a Long Term Evolution (LTE) system.

[0056] In the embodiments of the present application, the communication device for implementing the functions of a network device may be a network device, or a network device with partial base station functions, or a device capable of supporting the network device to implement such functions, such as a chip system, and this device may be installed in the network device.

[0057] (2) Terminal device

[0058] A terminal device may also be referred to as a user equipment (UE), access terminal, terminal unit, terminal station, mobile station, mobile device, remote station, remote terminal, mobile equipment, mobile terminal, terminal, wireless communication device, terminal agent, or terminal device, etc. Exemplarily, the terminal device includes a handheld device, in-vehicle device, wearable device, or computing device with wireless communication functions, a terminal device in a 5G network, or a terminal device in a future evolved PLMN network, etc. Exemplarily, the terminal device may be a mobile phone, a tablet computer, or a computer with wireless transceiver functions. The terminal device may also be a virtual reality (VR) terminal device, an augmented reality (AR) terminal device, a wireless terminal in industrial control, a wireless terminal in unmanned driving, a wireless terminal in remote medical treatment, a wireless terminal in a smart grid, a wireless terminal in a smart city, such as a smart fuel dispenser, a terminal device on a high-speed train, a wireless terminal in a smart home, such as a smart speaker, a smart coffee machine, a smart printer, and so on.

[0059] In the embodiments of the present application, the communication device for implementing the functions of a terminal device may be a terminal device, or a terminal device with partial terminal functions, or a device capable of supporting the terminal device to implement such functions, such as a chip system, and this device may be installed in the terminal device.

[0060] (3) Downlink control channel, downlink data channel

[0061] During the downlink transmission process, the signal sent by the network device to the terminal device is also called a downlink signal. The downlink signal includes a downlink control signal and a downlink data signal. In the embodiments of the present application, the downlink control channel is used to refer to the downlink control signal, that is, the downlink control channel can also be understood as the downlink control signal. The downlink control channel can be a physical downlink control channel (PDCCH). In the embodiments of the present application, the downlink data channel is used to refer to the downlink data signal, that is, the downlink data channel can also be understood as the downlink data signal. The downlink data channel can be a physical downlink shared channel (PDSCH).

[0062] The downlink control channel can be used to schedule the downlink data channel. For example, the PDCCH is used to transmit scheduling and configuration information related to the PDSCH. The PDSCH carries downlink data, and the PDCCH carries downlink control information (DCI). The DCI is used to indicate the configuration information of the PDSCH (for example, time / frequency position, modulation information, etc.). The DCI can also be used to indicate the indication information of the time-domain resource occupied by the feedback information corresponding to the PDSCH scheduled by the DCI. Among them, based on the hybrid automatic repeat request (HARQ) mechanism, the feedback information includes an acknowledge (ACK) message or a negative acknowledge (NACK) message, indicating whether the terminal device has successfully received the downlink data. The ACK can also be referred to as HARQ-ACK, and the NACK can also be referred to as HARQ-NACK. Specifically, after receiving the downlink data, if the terminal device receives it correctly, it will feedback an ACK message on the physical uplink control channel (PUCCH). If it is incorrect, it will feedback a NACK message on the PUCCH.

[0063] In addition, the DCI is divided into fallback DCI and non fallback DCI. Among them, the fallback DCI is the DCI of format 0_0 and 1_0, and the non fallback DCI is the DCI of format 0_1 / 0_2 and 1_1 / 1_2. The DCI of format 0_0 / 0_1 / 0_2 is used to schedule the uplink transmission, and the DCI of format 1_0 / 1_1 / 1_2 is used to schedule the downlink transmission.

[0064] (4) Unicast, multicast

[0065] The unicast transmission mode is a one-to-one data transmission mode. In the embodiments of the present application, unicast refers to a network device sending a downlink signal, such as unicast data, to a single terminal device.

[0066] The multicast transmission mode is a one-to-many data transmission mode. In the embodiments of the present application, multicast refers to a network device sending the same downlink signal, such as multicast data, to a group of terminal devices, and all terminal devices in this group can obtain the multicast data. Among them, a group of terminal devices includes multiple terminal devices. Optionally, a group of terminal devices can be located in the same cell. It can be understood that in the multicast transmission mode, a group of terminal devices can share resources, and the downlink signal sent by the network device on this resource can be received by a group of terminal devices. Compared with the unicast transmission mode, it can save resources for transmitting downlink signals.

[0067] It can be understood that the multicast in the embodiments of the present application can include multicast or broadcast, and this is not limited herein.

[0068] (5) Dynamic scheduling

[0069] Dynamic scheduling means that before each time the network device sends a PDSCH, it needs to send a PDCCH for scheduling this PDSCH. The PDSCH based on dynamic scheduling can also be referred to as the PDSCH with normal scheduling. It can be understood that the PDSCH with normal scheduling all has scheduling information. Dynamic scheduling can be used in multicast or unicast transmission scenarios.

[0070] Optionally, for unicast dynamic scheduling, the network device assigns a cell-radio network temporary identifier (C-RNTI) to a terminal device. Before each time the network device sends a PDSCH to multiple terminal devices in unicast mode, it sends DCI masked by the C-RNTI of each terminal device. Each terminal device can blindly detect the PDCCH according to its own C-RNTI and then receive downlink data. In addition, it should be noted that the C-RNTI is used to identify unicast dynamic scheduling and can be configured by the network device for a single terminal device. Of course, the C-RNTI can also be other identifiers as long as it can be used to identify unicast dynamic scheduling, and the embodiments of the present application do not limit this.

[0071] Optionally, for dynamic scheduling of multicast, the network device assigns the same group radio network temporary identifier (G-RNTI) to multiple terminal devices. Before each time the network device sends a PDSCH to multiple terminal devices via multicast, it sends DCI masked by the G-RNTI. Each terminal device can blindly detect the PDCCH based on the G-RNTI, and then receive the same PDSCH, or it can also be understood as receiving the downlink data carried by the PDSCH. In addition, it should be noted that the G-RNTI is used to identify multicast / broadcast scheduling and can be configured by the network device for a group of terminal devices. Of course, the G-RNTI can also be other identifiers, such as M-RNTI, as long as it can be used to identify multicast / broadcast scheduling. The embodiments of this application do not limit this.

[0072] (6) Semi-persistent scheduling (SPS)

[0073] Semi-persistent scheduling (SPS) means that the terminal device can receive the PDSCH periodically based on the semi-persistent scheduling configuration indicated by the network device. Semi-persistent scheduling can also be called semi-static scheduling. Before the network device sends the PDSCH to the terminal device for the first time, it first sends an activation PDCCH (or activation DCI) to the terminal device. This activation PDCCH is used to activate the corresponding SPS configuration. The activation PDCCH is also used to indicate the downlink time domain resources occupied by the downlink data scheduled by the activation PDCCH. Specifically, the aforementioned occupied downlink time domain resources can include the downlink time slot where the scheduled downlink data is located, as well as the start symbol S and length L of the downlink data in the downlink time slot. Subsequently, the terminal device can receive the PDSCH sent by the network device based on the activated SPS configuration. It can be understood that for the semi-persistent scheduling method, the PDSCH sent by the network device for the first time is scheduled by the activation PDCCH, and the PDSCH sent by the network device subsequently does not require other PDCCH scheduling and is all based on the activation PDCCH. Or it can also be understood that the PDSCH sent by the network device for the first time can be called the PDSCH with scheduling information, and the PDSCH sent by the network device subsequently is all PDSCH without scheduling information.

[0074] The network device can configure one or more sets of SPS configurations for the terminal device, such as up to 8 sets of SPS configurations. The parameters in each set of SPS configurations can be the same or different, and the parameters included in each set of SPS configurations can include at least one of the following: the index (ID) corresponding to this set of SPS configurations; the SPS transmission period; the configuration information of the physical uplink control channel (PUCCH) resources; the modulation and coding scheme table (MCS-table), where MCS refers to modulation and coding scheme; the information used to determine the hybrid automatic repeat request (HARQ) process.

[0075] Among them, the configuration information of the PUCCH resources is used to configure the symbols occupied by the PUCCH resources carrying the feedback information within a time slot. The configuration information of the PUCCH resources includes PUCCH format 0 or PUCCH format 1, indicating that the length of the feedback information that the PUCCH resources can accommodate is 1 bit or 2 bits. It should be noted that if the network device configures one set of SPS configurations for the terminal device, the terminal device can perform feedback based on the PUCCH resources indicated in this set of SPS configurations; if the network device configures multiple sets of SPS configurations for the terminal device, the terminal device needs to determine the PUCCH resources used to carry the feedback information from the set of PUCCH resources of the SPS, and the aforementioned set of PUCCH resources of the SPS is configured in the PUCCH-config configured at a higher layer.

[0076] The modulation and coding scheme table is used to indicate the modulation and coding scheme adopted by the scheduled PDSCH, and specifically can be represented by the MCS index.

[0077] The aforementioned information used to determine the HARQ process includes the number of HARQ processes available for the SPS and the configured offset. The specific HARQ process ID can be determined in the following way:

[0078] HARQ Process ID = [floor(CURRENT_slot × 10 / (numberOfSlotsPerFrame × periodicity))] modulo nrofHARQ-Processes + harq-ProcID-Offset;

[0079] Among them, CURRENT_slot = [(SFN × numberOfSlotsPerFrame) + slot number in the frame]

[0080] The SFN represents the system frame number, numberOfSlotsPerFrame is the number of time slots in each subframe, slot number in the frame represents the index of the current time slot, periodicity is the scheduling period, nrofHARQ - Processes is the number of HARQ processes available for the SPS, and harq - ProcID - Offset is the configured offset.

[0081] It can be understood that the HARQ process ID here is used to identify the HARQ process used by the terminal device to receive the PDSCH transmitted based on SPS after the SPS configuration is activated.

[0082] Based on semi - persistent scheduling, the network device does not need to send the PDCCH for scheduling before sending downlink data each time, which can reduce the overhead of control signaling compared with the dynamic scheduling method. In related technical solutions, semi - persistent scheduling is applied to the unicast scenario. For example, before the network device sends downlink data to a single terminal device for the first time, it sends an activation DCI. The terminal device blindly detects this activation DCI in the PDCCH, and then receives the downlink data sent by the network device for the first time based on the downlink time - domain resources indicated by this activation DCI. When the network device sends downlink data subsequently, it no longer sends DCI for scheduling, and the terminal device receives the downlink data based on the activated SPS configuration. However, there is a lack of design for applying semi - persistent scheduling to the multicast scenario. Considering that the multicast method can save downlink resources, while the dynamic scheduling of multicast will increase the overhead of control signaling, the embodiments of this application provide an implementation solution for semi - persistent scheduling of multicast, and this solution will be described in detail in the following content.

[0083] (7) Scrambling

[0084] In the embodiments of this application, scrambling means that the CRC check bits corresponding to the DCI carried in the PDCCH are scrambled using a specific RNTI. For the convenience of description, after a DCI is scrambled using a specific RNTI, it is simply referred to as the DCI scrambled with this RNTI. Since the DCI is carried in the PDCCH, it can also be referred to as the PDCCH scrambled with this RNTI. For example, the DCI scrambled with C - RNTI, the DCI scrambled with G - RNTI, etc.

[0085] (8) Blind detection

[0086] In the blind detection in the embodiments of the present application, it means that the terminal device performs blind detection on the PDCCH using a specific RNTI to attempt to receive possible DCI. For the convenience of description, it can also be said that the terminal device performs blind detection on the DCI using a specific RNTI, or it can be said that the terminal device performs blind detection on the DCI using a specific RNTI on the PDCCH, etc. For example, the terminal device performs blind detection on the PDCCH (DCI) using the C-RNTI, etc.

[0087] (9) In the embodiments of the present application, "a plurality of" involved means two or more. "And / or" describes the association relationship of associated objects, indicating that there can be three relationships. For example, A and / or B can represent: A exists alone, A and B exist simultaneously, and B exists alone. The character " / " generally represents an "or" relationship between the associated objects before and after. In addition, it should be understood that although terms such as first and second may be used in the embodiments of the present application to describe each object, these objects should not be limited to these terms. These terms are only used to distinguish each object from each other.

[0088] (10) In the description of the embodiments of the present application, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or device that includes a series of steps or units is not limited to the listed steps or units, but optionally further includes other steps or units not listed, or optionally further includes other steps or units inherent to these processes, methods, products, or devices. It should be noted that in the embodiments of the present application, words such as "exemplary" or "for example" are used to represent examples, illustrations, or explanations. Any embodiment or design solution described as "exemplary" or "for example" in the embodiments of the present application should not be interpreted as being more preferred or having more advantages than other embodiments or design solutions. Exactly, using words such as "exemplary" or "for example" is intended to present relevant concepts in a specific manner.

[0089] In view of the problem of relatively large control signaling overhead in the dynamic scheduling of multicast, the embodiments of the present application provide a data transmission method. By implementing a semi-persistent scheduling scheme for multicast, while saving downlink resources, it can reduce control signaling overhead and improve the data transmission efficiency.

[0090] Refer to Figure 1 In the schematic communication system, the data transmission method provided by the embodiments of the present application can be applied to this communication system. This communication system includes at least one terminal device and at least one network device. Exemplarily, Figure 1 One network device and six terminal devices are schematically shown, such as UE1, UE2, UE3, UE4, UE5, and UE6.

[0091] The network device can instruct multiple terminal devices to activate the semi-continuous scheduling configuration by multicast, or it can be understood that the network device instructs multiple terminal devices to activate the multicast semi-continuous scheduling SPS transmission, and then sends the downlink data based on the multicast semi-continuous scheduling transmission to multiple terminal devices by multicast, and the downlink data can be referred to as the group SPS PDSCH; each terminal device can receive the aforementioned group SPS PDSCH based on the multicast semi-continuous scheduling transmission, and send the feedback information corresponding to the group SPS PDSCH to the network device. The network device can receive the feedback information corresponding to the group SPS PDSCH sent by each terminal device, and the feedback information can be ACK or NACK. The network device determines whether the aforementioned group SPS PDSCH needs to be retransmitted based on the feedback information sent by each terminal device. In addition, the network device can also instruct multiple terminal devices to deactivate the semi-continuous scheduling configuration by multicast, or it can be understood that the network device instructs multiple terminal devices to deactivate the multicast semi-continuous scheduling SPS transmission.

[0092] The data transmission method provided in the embodiment of the present application can be applied to the following communication services: enhanced mobile broadband (eMBB), massive machine type communication (mMTC) and ultra-reliable and low-latency communication (URLLC). For example, it can be applied to scenarios such as unmanned driving and telemedicine of URLLC services, and the instruction overhead can be reduced as much as possible while meeting the requirements of high reliability and low latency.

[0093] The data transmission method provided in the embodiment of the present application may include at least one of the following processes: activation of multicast semi-continuously scheduled transmission, deactivation of multicast semi-continuously scheduled transmission, and retransmission of data related to multicast semi-continuously scheduled transmission. For example, the data transmission method includes activation of multicast semi-continuously scheduled transmission and deactivation of multicast semi-continuously scheduled transmission; for another example, the data transmission method includes activation of multicast semi-continuously scheduled transmission and retransmission of data related to multicast semi-continuously scheduled transmission; for another example, the data transmission method includes activation of multicast semi-continuously scheduled transmission, retransmission of data related to multicast semi-continuously scheduled transmission, and deactivation of multicast semi-continuously scheduled transmission. The above process is further described in detail below in combination with Scheme 1 and Scheme 2. It should be noted that Scheme 1 and Scheme 2 can be implemented in combination with each other or independently.

[0094] In the following method, the steps of the network device can be implemented by different functional entities that make up the network device. In other words, the functional entities that execute the steps of the network device can be located in different physical entities. For example, the actions of sending or receiving by the network device can be located in the radio frequency (RF) unit of the network device, or in the radio remote unit (RRU), or in the active antenna unit (AAU). The actions processed by the network device can be located in the central unit CU of the network device, etc. This application does not limit this.

[0095] Solution 1:

[0096] A1. Activation of multicast semi-persistent scheduling transmission

[0097] The network device can configure the same group-configured scheduling-radio network temporary identifier (G-CS-RNTI) for multiple terminal devices. Before the network device sends the same downlink data (i.e., the aforementioned group SPS PDSCH) to multiple terminal devices for the first time, it sends a DCI masked by the G-CS-RNTI. The terminal device blindly detects the DCI masked by the G-CS-RNTI on the PDCCH, and then activates the multicast semi-persistent scheduling SPS transmission based on the DCI masked by the G-CS-RNTI, and receives the group SPS PDSCH sent by the network device for the first time. It should be noted that the G-CS-RNTI is used to identify the multicast semi-persistent scheduling, and can also be used to identify the retransmission scheduling based on the multicast semi-persistent scheduling, and can be configured by the network device for a group of terminal devices. Of course, the G-CS-RNTI can also be replaced by other identifiers, as long as it can be used to identify the multicast semi-persistent scheduling or the retransmission scheduling based on the multicast semi-persistent scheduling. This embodiment of the present application does not limit this.

[0098] Optionally, the DCI masked by the G-CS-RNTI for activating the multicast semi-persistent scheduling SPS transmission can be abbreviated as the activation DCI. The following details the content included in the DCI masked by the G-CS-RNTI sent by the network device.

[0099] Optionally, the DCI masked by G-CS-RNTI sent by the network device includes information for identifying the DCI as an active DCI. For example, the DCI includes a Redundancy Version field, and the Redundancy Version field being all 0 indicates that the DCI is an active DCI. Then, the terminal device receives a DCI according to G-CS-RNTI. If the received DCI includes information for identifying the DCI as the aforementioned active DCI, the terminal device knows that the received DCI is an active DCI and is used to activate the semi-persistent scheduling (SPS) transmission of multicast.

[0100] Optionally, the DCI masked by G-CS-RNTI sent by the network device may indicate at least one of the following time parameters: the time slot where the group SPS PDSCH is located; the start symbol S and length L of the group SPS PDSCH in the time slot; the time slot where the feedback information corresponding to the group SPS PDSCH is located. Exemplarily, the DCI may include a bit field for indicating the resources occupied by the data scheduled by the DCI in the time domain: the Time domain resource assignment field, and the value range of the number of bits occupied by the time domain resource assignment field is [0, 4]. Optionally, the DCI masked by G-CS-RNTI sent by the network device may further include a bit field for indicating the resources occupied by the data scheduled by the DCI in the frequency domain: the Frequency domain resource assignment field. Optionally, the DCI masked by G-CS-RNTI sent by the network device may further include a bit field for indicating the modulation and coding scheme of the data scheduled by the DCI: the Modulation and coding scheme (MCS) field.

[0101] Optionally, the time slot in which the group SPS PDSCH is located, and the ways of S and L are as follows: The DCI carried in the PDCCH and masked by the G-CS-RNTI indicates a row in a time domain resource table, which can be a protocol-predefined table or a table configured by higher layer signaling. The table contains multiple rows, and each row contains: parameter K0, parameter S, and L; where K0 is used to indicate the number of time slots between the time slot where the PDCCH is located and the time slot where the PDSCH is located; S and L can be jointly encoded into one parameter: start symbol and length (SLIV), or two separate independent parameters, represented by (S, L). Exemplarily, Table 1 shows a time domain resource table. The DCI may specifically include a bit field indicating the row index, which may occupy 2 bits. For example, if the index included in the DCI is 1, it means that the DCI indicates that K0 is 1 and (S, L) is (1, 2), that is, if the terminal device receives the DCI masked by the G-CS-RNTI in the nth time slot, it can receive the group SPS PDSCH scheduled by the DCI in the (n + 1)th time slot, specifically receive the group SPS PDSCH scheduled by the DCI in symbol 1 and symbol 2 in the (n + 1)th time slot.

[0102] Table 1

[0103] Index K0 (S,L) 0 1 (2,4) 1 1 (1,2) 2 2 (3,4) 3 2 (0,7)

[0104] Optionally, the method for indicating the time slot where the feedback information corresponding to the group SPS PDSCH is located is as follows: Include an indication information in the DCI, which can specifically use the PDSCH-to-HARQ_feedback timing indicator bit field to represent the foregoing indication information. The number of bits that the bit field can occupy ranges from [0, 3]. This bit field is used to indicate at which moment the terminal device performs feedback, that is, sends the corresponding feedback information after receiving the group SPS PDSCH. Optionally, the indication information may be a value of K1 in the set of K1. The set of K1 (such as the dl-DataToUL-ACK field) can be a set configured by higher layer signaling, and the value of K1 represents the number of time slots between the time slot where the group SPS PDSCH is located and the corresponding feedback information. Assuming that the group SPS PDSCH is in the (n + 1)th time slot, the feedback information corresponding to the group SPS PDSCH is in the (n + 1 + K1)th time slot. Exemplarily, the value of K1 can be 4, and the feedback information is specifically an ACK message or a NACK message. The time slot may also be a sub-time slot.

[0105] For the terminal device, after determining the feedback time slot of the group SPS PDSCH based on the foregoing DCI indication, it is also necessary to determine the feedback resources that the feedback information can specifically occupy. The manner in which the terminal device determines the feedback resources can be implemented with reference to the following manner:

[0106] The terminal device first determines the number of bits of the feedback information corresponding to the group SPS PDSCH that needs to be feedback in the feedback time slot. For example, the sum of the number of bits of the feedback information of all the group SPS PDSCHs to be feedback in the feedback time slot is used as the number of bits of the feedback information. Then, in the semi-persistent scheduling PUCCH resource set pre-configured by the network device, a PUCCH resource is selected according to the number of bits of the feedback information to send the feedback information of the group SPS PDSCH.

[0107] Exemplarily, assume that the network device configures 4 PUCCH resources for the terminal device. If the number of bits of the feedback information is less than or equal to 2, the first PUCCH resource is used to send the feedback information of the group SPS PDSCH; if the number of bits is between 3 and N1, the second PUCCH resource is used; if the number of feedback bits is between N1 and N2, the third PUCCH resource is used; if the number of feedback bits is between N2 and N3, the fourth PUCCH resource is used, where N1 is less than N2 and greater than 2, and N2 is less than N3; N1, N2, and N3 are also indicated by the network device when sending configuration information (such as in the high-layer signaling). If there is no indication, the default value is 1706.

[0108] Optionally, the DCI masked by the G-CS-RNTI may further include information indicating which semi-persistent scheduling SPS configuration this DCI is used to activate. Exemplarily, if the network device configures multiple SPS configurations for the terminal device, specifically, the HARQ process number (HPN) bit field in the DCI can be used to indicate the activated semi-persistent scheduling SPS configuration. The range of the number of bits that this bit field can occupy is [0,4]. The terminal device can determine the activation of the multicast semi-persistent scheduling SPS transmission through the value of the HARQ process number, specifically corresponding to which one of the foregoing multiple SPS configurations is activated. Or, if the network device configures 1 SPS configuration for the terminal device, the HARQ process number in this DCI defaults to 0 through the value of the HARQ process number.

[0109] Optionally, the DCI masked by the G-CS-RNTI may further include information indicating that the group SPS PDSCH scheduled by the DCI is initial transmission data. Exemplarily, the DCI may include a 1-bit field, denoted as the New Data Indicator (NDI), where an NDI value of 0 indicates that the group SPS PDSCH scheduled by the DCI is initial transmission data.

[0110] Furthermore, when the network device subsequently transmits the group SPS PDSCH, it does not need to first transmit a DCI for scheduling, and the terminal device receives the group SPS PDSCH based on the activated SPS configuration. Refer to Figure 2 , the network device transmits a DCI masked by the G-CS-RNTI to schedule the group SPS PDSCH in time unit 1 before the first transmission of the group SPS PDSCH in time unit 2. This DCI is used to activate the semi-static SPS transmission of multicast; optionally, the DCI includes information for indicating the semi-persistent scheduling SPS configuration, and this DCI is specifically used to activate the SPS configuration. In subsequent time units, the network device does not need to transmit other DCIs when transmitting the group SPS PDSCH, and the terminal device can receive the subsequent group SPS PDSCH based on the aforementioned activated SPS configuration. Exemplarily, Figure 2 shows that the subsequent terminal device periodically receives the group SPS PDSCH in time units 3-6 without receiving a DCI.

[0111] It should be noted that the time unit here refers to the time unit of SPS scheduling, which is a time domain concept. The time unit can be in units of frames, sub-frames, time slots, and symbols. Exemplarily, in the 5G NR system, with a subcarrier spacing of 15 kHz, the time length of a time slot is 1 ms. In the case of using an extended cyclic prefix, a time slot includes 12 symbols; in the case of using a normal cyclic prefix, a time slot includes 14 symbols. The symbol here, or the time domain symbol, can be an orthogonal frequency division multiplexing (OFDM) symbol. It can be understood that Figure 2 the time units 1-6 in do not necessarily mean consecutive time units. For example, between time units 2-6, there is an SPS period interval between adjacent two time units.

[0112] Optionally, the terminal device can determine the time slot position of the subsequent group SPS PDSCH according to the SPS transmission period P configured by the upper layer. For example, if the SPS transmission period P is 1 ms and the time domain duration of one time slot is 1 ms, and the first group SPS PDSCH is in symbols 1 and 2 of the (n + 1)-th time slot, then in the case of activating the multicast SPS, the position of the group SPS PDSCH is from the (n + 1)-th time slot, occupying symbols 1 and 2 of each time slot, where x is an integer greater than 1. It can be understood that Figure 2 the time unit shown in Figure 2 can refer to a time slot. Then, as an example,

[0113] shows that the time unit 1 where the DCI masked with G-CS-RNTI is located is the n-th time slot, and the position of the group SPS PDSCH starts from the (n + 1)-th time slot, that is, from time unit 2, and each time unit such as time unit 3 and time unit 4. In addition, the foregoing scheduling period P can also be other values, depending on the upper layer configuration. If the SPS transmission period P configured by the upper layer is 2 ms and the first group SPS PDSCH is in symbols 1 and 2 of the (n + 1)-th time slot, then in the case of activating the multicast SPS, the position of the group SPS PDSCH starts from the (n + 1)-th time slot, occupying symbols 1 and 2 within every other time slot, that is, the position of the group SPS PDSCH is the (n + 1 + x * 2)-th time slot, where x is an integer greater than or equal to 0. It can be understood that in this example, assuming that the duration of one time unit is 1 ms and the SPS scheduling period is 1 ms, it corresponds to 1 time unit, that is, SPS PDSCH is transmitted in each time unit; when the SPS scheduling period is 2 ms, it corresponds to 2 time units, that is, SPS PDSCH is transmitted at an interval of one time unit. Among them, the foregoing upper layer can be understood as the upper layer protocol layer, including at least one protocol layer above the physical layer: the medium access control (MAC) layer, the radio link control (RLC) layer, the packet data convergence protocol (PDCP) layer, the radio resource control (RRC) layer, and the non-access stratum (NAS) layer. Correspondingly, in various embodiments of the present application, the upper layer signaling can be NAS layer signaling, RRC messages, or media access control (MAC) control elements (CEs). The RRC messages can include dedicated RRC messages or broadcast / multicast RRC messages, and the embodiments of the present application are not limited thereto.

[0114] A2, data retransmission related to semi-persistent scheduling transmission of multicast

[0115] Regarding the retransmission of group SPS PDSCH, it can be implemented in the following three cases:

[0116] Case 1: If the feedback information of the group SPS PDSCH of a large number of terminal devices is all NACK information, that is, a large number of terminal devices fail to successfully receive the group SPS PDSCH, the network device can send the retransmission data of the aforementioned group SPS PDSCH in a multicast manner, or it can be said to retransmit the aforementioned group SPS PDSCH.

[0117] Among them, a quantity threshold can be set. If, among a group of terminal devices, there are terminal devices greater than or equal to the set quantity threshold that fail to successfully receive the group SPS PDSCH sent by the network device and all feedback NACK information to the network device, the network device can determine that there are a large number of terminal devices that fail to successfully receive the group SPS PDSCH. Exemplarily, for example, a group of terminal devices includes 6 terminal devices, and the set quantity threshold can be 3. When the feedback information sent by 3 or more than 3 terminal devices to the network device is NACK information, the network device can send the retransmission data of the group SPS PDSCH that has not been successfully received in a multicast manner.

[0118] Exemplarily, after receiving NACK information sent by multiple terminal devices, the network device can send a DCI masked by G-CS-RNTI to the multiple terminal devices in a multicast manner. Here, the DCI is used to schedule the retransmission data, and the retransmission data may be the retransmission data of one SPS PDSCH among multiple SPS PDSCHs for the aforementioned activated multicast SPS transmission. The DCI includes NDI, and the value of NDI being 1 indicates that the PDSCH scheduled by the DCI is retransmission data. The DCI can also include HPN, indicating the HARQ process occupied by the retransmission. Optionally, the HARQ process occupied by the retransmission indicated by the HPN is the same as the HARQ process calculated according to the activated SPS configuration. That is, the terminal device receives the DCI masked by G-CS-RNTI, and according to the NDI with a value of 1 in the DCI, it can know that the DCI schedules retransmission data, and can know the HARQ process for receiving the retransmission data according to the HPN in the DCI, which is convenient for soft combination of the retransmission data.

[0119] Case 2: If the feedback information of the group SPS PDSCH of a group with fewer terminal devices is all NACK information, that is, there are fewer terminal devices that fail to receive the group SPS PDSCH successfully, the network device can unicast the retransmission data of the aforementioned group SPS PDSCH to the terminal devices that fail to receive the group SPS PDSCH successfully, separately.

[0120] Among them, a quantity threshold can be set. If among a group of receiving terminal devices, there are terminal devices less than the set quantity threshold that fail to receive the group SPS PDSCH sent by the network device and feedback NACK information to the network device, then the network device can determine that there are fewer terminal devices that fail to receive the group SPS PDSCH successfully. Exemplarily, for example, a group of terminal devices includes 6 terminal devices, and the set quantity threshold can be 3. When the feedback information sent by 1 or 2 terminal devices to the network device is NACK information, the network device can unicast the retransmission data of the group SPS PDSCH that has not been received successfully.

[0121] Case 3: The network device configures or notifies the retransmission scheduling method for the terminal devices. Specifically, among a group of terminal devices, the network device configures or notifies that the retransmission scheduling method for some terminal devices is based on unicast, and configures or notifies that the retransmission scheduling method for some terminal devices is based on multicast. If the retransmission scheduling method is configured or notified to be based on unicast, and a terminal device fails to receive the group SPS PDSCH sent by the network device and feedbacks NACK information to the network device, then the network device transmits the retransmission data of the group SPS PDSCH to this terminal device through unicast-based retransmission scheduling. If the retransmission scheduling method is configured or notified to be based on multicast, and a terminal device fails to receive the group SPS PDSCH sent by the network device and feedbacks NACK information to the network device, then the network device transmits the retransmission data of the group SPS PDSCH to this terminal device through multicast-based retransmission scheduling. Exemplarily, for example, a group of terminal devices includes 6 terminal devices. Terminal device #1 is configured with unicast-based retransmission scheduling, and terminal devices #2 to #6 are configured with multicast-based retransmission scheduling. If the feedback information sent by terminal device #1 to the network device is NACK information, the network device can unicast the retransmission data of the group SPS PDSCH that has not been received successfully to terminal device #1. If the feedback information sent by any one of terminal devices #2 to #6 to the network device is NACK information, the network device multicasts the retransmission data of the group SPS PDSCH that has not been received successfully to terminal devices #2 to 6.

[0122] Optionally, after receiving the NACK information sent by the terminal device, the network device may send DCI masked by a configured scheduling network temporary identifier (CS-RNTI) to the terminal device. The DCI is used to schedule retransmission data, and the DCI includes an NDI. A value of 1 for the NDI indicates that the group SPS PDSCH scheduled by the DCI is retransmission data. The DCI here includes an HPN field indicating the HARQ process occupied by the retransmission. Optionally, the HPN indicates that the HARQ process occupied by the retransmission is the same as the HARQ process calculated according to the activated SPS configuration. That is, when the terminal device receives the DCI masked by the CS-RNTI, it can know that the DCI schedules retransmission data according to the NDI with a value of 1 in the DCI, and then know the HARQ process occupied by receiving the retransmission data according to the HPN in the DCI, which is convenient for soft combining of the retransmission data. It should be noted that in the embodiments of the present application, the CS-RNTI is used to identify unicast transmission and can be configured by the network device for a single terminal device. Of course, the CS-RNTI can also be replaced by other identifiers as long as they can be used to identify unicast transmission, and the embodiments of the present application do not limit this. It can be understood that if terminal device 1 and terminal device 2 send NACKs, the network device sends DCI to these two terminal devices respectively. For example, the DCI masked by the CS-RNTI of terminal device 1 is sent to terminal device 1, and the foregoing SPS PDSCH is retransmitted to terminal device 1 in a unicast manner. The DCI masked by the CS-RNTI of terminal device 2 is sent to terminal device 2, and the foregoing SPS PDSCH is retransmitted to terminal device 2 in a unicast manner.

[0123] Exemplarily, refer to Figure 3, which illustrates the retransmission scheduling mechanism of the aforementioned unicast. Assume that a single terminal device fails to successfully receive the group SPS PDSCH sent by the network device in time unit 1. Then, according to the PDSCH-to-HARQ_feedback timing indicator in the DCI masked by G-CS-RNTI in the aforementioned activation phase A1, the feedback time unit of the feedback information is determined to be time unit 2. Then, a NACK message is sent to the network device on the PUCCH in time unit 2. After receiving the PUCCH, the network device determines that the terminal device has fed back a NACK. Then, the network device sends the retransmission data of a group SPS PDSCH to this terminal device in a unicast manner. Specifically, the network device sends the DCI masked by CS-RNTI to the terminal device in time unit 3. The terminal device blindly detects the aforementioned DCI masked by CS-RNTI on the PDCCH. The HARQ process indicated by HPN in this DCI is the same as the HARQ process calculated according to the activated SPS configuration. For example, both are HARQ process: N. The value of NDI in this DCI is 1. Then, the terminal device knows that the DCI masked by CS-RNTI schedules the retransmission data, and this retransmission data is the retransmission data of the aforementioned SPS PDSCH. Then, the terminal device can perform soft combining on the data received in this group SPS PDSCH retransmission with the data in the initial transmission group SPS PDSCH.

[0124] In the embodiments of this application, the network device can perform retransmission scheduling on the multicast SPS data through the DCI masked by CS-RNTI, that is, send the retransmission data of the group SPS PDSCH to a single terminal device in a unicast manner. This method does not introduce a new RNTI and can save the resources used by the terminal device for blindly detecting the DCI.

[0125] A3, Deactivation of Multicast Semi-Persistent Scheduling Transmission

[0126] The network device can send a deactivation DCI masked by G-CS-RNTI to multiple terminal devices. The Redundancy Version field in the deactivation DCI is all 0, the Modulation and coding scheme field is all 1, and the Frequency domain resource assignment field is all 1 (i.e., Type1) or all 0 (i.e., Type0). Based on the foregoing information in the deactivation DCI, the terminal device can know that the deactivation DCI is used to deactivate the semi-persistent scheduling (SPS) transmission of multicast. Other information such as HPN is also included in the deactivation DCI. The value of the HPN can be the same as the value of the HPN in the DCI during the activation phase (A1). The terminal device can deactivate the SPS configuration indicated by the HPN based on the HPN in the deactivation DCI and no longer receive the group SPS PDSCH of the deactivated SPS configuration in subsequent time units. Exemplarily, as Figure 4 illustrates that the network device sends a deactivation DCI masked by G-CS-RNTI in time unit 1, and the terminal device blindly detects the deactivation DCI on the PDCCH. According to the HPN in the deactivation DCI, it is determined that the group SPS PDSCH corresponding to the HPN will no longer be received, Figure 4 specifically represented by "×" indicating that the group SPS PDSCH on time units 2-6 will no longer be received, or it can be understood that the network device will no longer send the group SPS PDSCH on time units 2-6.

[0127] It should be noted that Solution 1 can include one or more of the above stages A1 to A3, and the execution order of stages A1 to A3 can be determined based on actual requirements, which is not limited in the embodiments of this application.

[0128] Solution 2:

[0129] Indicator information for indicating dynamic scheduling transmission or semi-persistent scheduling (SPS) transmission can be included in the DCI. The DCI and the group-radio network temporary identifier (G-RNTI) are jointly used to indicate multicast dynamic scheduling or multicast semi-persistent scheduling. It should be noted that the G-RNTI is used to identify multicast transmission and can be configured by the network device for a group of terminal devices. Of course, the G-RNTI can also be replaced by other identifiers as long as they can be used to identify multicast transmission, which is not limited in the embodiments of this application.

[0130] In an alternative embodiment, the DCI may include a target bit field for indicating dynamic scheduling or semi-persistent scheduling (SPS). The target bit field may occupy 1 bit. When the value of the target bit field is 0, it indicates that the DCI indicates dynamic scheduling; when the value of the target bit field is 1, it indicates that the DCI indicates semi-persistent scheduling (SPS). Or vice versa, when the value of the target bit field is 1, it indicates that the DCI indicates dynamic scheduling; when the value of the target bit field is 0, it indicates that the DCI indicates semi-persistent scheduling (SPS).

[0131] In another alternative embodiment, considering that both the dynamic scheduling of multicast or the semi-persistent scheduling of multicast are downlink communications, when the DCI jointly indicates the dynamic scheduling of multicast or the semi-persistent scheduling of multicast with the G-RNTI, the description of the Identifier for DCI formats field in the traditional DCI format may be changed, and the value of the Identifier for DCI formats field is used to distinguish between the dynamic scheduling of multicast and the semi-persistent scheduling of multicast. For example, if the value of the Identifier for DCI formats field in the DCI is 0, it indicates that the DCI indicates dynamic scheduling; if the value of the Identifier for DCI formats field in the DCI is 1, it indicates that the DCI indicates semi-persistent scheduling (SPS). Or vice versa, if the value of the Identifier for DCI formats field in the DCI is 1, it indicates that the DCI indicates dynamic scheduling; if the value of the Identifier for DCI formats field in the DCI is 0, it indicates that the DCI indicates semi-persistent scheduling (SPS).

[0132] Optionally, based on the foregoing manner of joint indication by the G-RNTI and the DCI, the activation of the semi-persistent scheduling of multicast, the retransmission related to the semi-persistent scheduling of multicast, and the deactivation of the semi-persistent scheduling of multicast may be implemented in the following manners B1 to B3.

[0133] B1. Activation of the semi-persistent scheduling transmission of multicast

[0134] The network device may configure the same group radio network temporary identifier (G-RNTI) for multiple terminal devices. Before the network device sends the same downlink data (i.e., group SPS PDSCH) to multiple terminal devices for the first time, it sends a DCI masked by the G-RNTI. The DCI contains information for indicating semi-persistent scheduling transmission for multicast, such as the aforementioned target bit field. When the terminal device blindly detects the DCI masked by the G-RNTI in the PDCCH and determines that the DCI contains information for indicating SPS configuration, it can activate the SPS configuration for multicast based on the DCI masked by the G-CS-RNTI and receive the group SPS PDSCH sent by the network device for the first time.

[0135] Optionally, the DCI masked by the G-RNTI for activation can also be understood as an activation DCI. For other content included in the DCI masked by the G-RNTI sent by the network device, reference can be made to the description of the content included in the DCI masked by the G-CS-RNTI in A1, and this will not be elaborated in the embodiments of this application.

[0136] Furthermore, when the network device sends the group SPS PDSCH subsequently, it does not need to send a DCI for scheduling first. The terminal device receives the group SPS PDSCH based on the activated SPS configuration. Refer to Figure 5 , at time unit 1 before the network device sends the group SPS PDSCH for the first time at time unit 2, it sends a DCI masked by the G-RNTI to schedule the group SPS PDSCH. The DCI is used to activate semi-static SPS transmission for multicast; optionally, the DCI contains information for indicating semi-persistent scheduling SPS configuration, and the DCI is specifically used to activate the SPS configuration. In subsequent time units, the network device does not need to send other DCIs when sending the group SPS PDSCH, and the terminal device can receive the subsequent group SPS PDSCH based on the aforementioned activated SPS configuration. Exemplarily, Figure 5 shows that subsequently, the terminal device periodically receives the group SPS PDSCH at time units 3-5 without receiving other DCIs.

[0137] In addition, the network device can also perform dynamic scheduling for multicast while performing semi-persistent scheduling for multicast. As Figure 5It is also shown that the network device sends data for multicast-based dynamic scheduling transmission for the first time in time unit 2. For example, in time unit 1 before the dynamically scheduled Physical Downlink Shared Channel (Dynamic scheduling PDSCH, DYN PDSCH), a DCI masked with a G-RNTI is sent to schedule the DYN PDSCH. Here, the DCI includes information for indicating dynamic scheduling. Then, the terminal device can blindly detect two DCIs masked with a G-RNTI on the Physical Downlink Control Channel (PDCCH) in time unit 1. To distinguish them Figure 5 They are represented as DCI-1 and DCI-2. Among them, DCI-1 schedules the DYN PDSCH in time unit 2. DCI-2 schedules the semi-persistent scheduling Physical Downlink Shared Channel (SPS PDSCH) of the group in time unit 2 and subsequent time units. Taking the case where the target bit value of 0 indicates dynamic scheduling and the target bit value of 1 indicates semi-persistent scheduling as an example, the target bit value in DCI-1 is 0, and the target bit value in DCI-2 is 1.

[0138] B2, retransmission of data related to multicast semi-persistent scheduling transmission

[0139] Regarding the retransmission of the group SPS PDSCH, it can be implemented in the following three cases:

[0140] Case 1: If the feedback information of the group SPS PDSCH of a relatively large number of terminal devices is all NACK information, that is, a relatively large number of terminal devices fail to successfully receive the group SPS PDSCH, the network device can send the retransmission data of the aforementioned group SPS PDSCH in a multicast manner.

[0141] Optionally, the network device can schedule the retransmission data of the aforementioned group SPS PDSCH based on a DCI masked with a G-RNTI. The specific implementation method can refer to the solution in Case 1 of A2, and this application embodiment will not elaborate on it here.

[0142] Case 2: If the feedback information of the group SPS PDSCH of a relatively small number of terminal devices is all NACK information, that is, a relatively small number of terminal devices fail to successfully receive the group SPS PDSCH, the network device can send the retransmission data of the aforementioned group SPS PDSCH to the terminal devices that fail to successfully receive the group SPS PDSCH individually in a unicast manner.

[0143] Optionally, the network device can schedule the retransmission data of the aforementioned group SPS PDSCH based on a DCI masked with a Cell-specific Radio Network Temporary Identifier (CS-RNTI). The specific implementation method can refer to the solution in Case 2 of A2, and this application embodiment will not elaborate on it here.

[0144] Case 3: If a retransmission scheduling method is configured or notified as unicast and the UE fails to receive the group SPS PDSCH, the feedback information sent is NACK, and the network device sends the retransmission data of the foregoing group SPS PDSCH to the UE for which the retransmission scheduling method is configured or notified as unicast through a unicast-based scheduling method; if a retransmission scheduling method is configured or notified as multicast and the UE fails to receive the group SPS PDSCH, the feedback information sent is NACK, and the network device sends the retransmission data of the foregoing group SPS PDSCH to the UE for which the retransmission scheduling method is configured or notified as multicast through a multicast-based scheduling method.

[0145] Optionally, the network device may schedule the retransmission data of the foregoing group SPS PDSCH to the UE for which the retransmission scheduling method is configured as unicast based on the DCI masked by CS-RNTI, and may schedule the retransmission data of the foregoing multicast SPS PDSCH to the UE for which the retransmission scheduling method is configured as multicast based on the DCI masked by G-RNTI or G-CS-RNTI. The specific implementation manner may refer to the solution in Case 3 of A2, and the embodiments of the present application will not elaborate on this again.

[0146] B3, Deactivation of Multicast Semi-Persistent Scheduling

[0147] The network device may send a deactivation DCI masked by G-RNTI to multiple UEs. The Redundancy Version field in the deactivation DCI is all 0, the Modulation and Coding Scheme field is all 1, and the Frequency Domain Resource Assignment field is all 1 (i.e., Type1) or all 0 (i.e., Type0). Based on the foregoing information in the deactivation DCI, the UE can know that the deactivation DCI is used to deactivate the multicast semi-persistent scheduling SPS. Other information such as HPN is also included in the deactivation DCI. The value of the HPN may be the same as the value of the HPN in the DCI during the activation phase (A1). The UE may deactivate the SPS configuration indicated by the HPN based on the HPN in the deactivation DCI and no longer receive the group SPS PDSCH of the deactivated SPS configuration in subsequent time units. Exemplarily, as Figure 6 It is shown that the network device sends a deactivation DCI masked by G-RNTI in time unit 1, then the UE blindly detects the deactivation DCI on the PDCCH, and determines not to receive the group SPS PDSCH corresponding to the SPS configuration of the HPN based on the HPN in the deactivation DCI. Figure 6Specifically, "×" is used to indicate that the network device no longer receives the group SPS PDSCH on time units 2-5, or it can be understood that the network device also no longer sends the group SPS PDSCH on time units 2-5.

[0148] It should be noted that Solution 1 may include one or more of the above stages B1 to B3, and the execution order of stages B1 to B3 can be determined based on actual requirements, and the embodiments of the present application do not limit this.

[0149] In the above Solution 2 provided by the embodiments of the present application, by defining a method for indicating semi-persistent scheduling or dynamic scheduling in DCI, dynamic scheduling of multicast data or semi-persistent scheduling of multicast data can be achieved using G-RNTI, which expands the application scenario of G-RNTI, saves the resources of blind detection on the terminal device side, and also reduces the control signaling overhead during the downlink data scheduling of multicast.

[0150] Based on the above Solution 1 and Solution 2, see Figure 7 , the embodiments of the present application provide a schematic flowchart of a data transmission method. The method includes the following processes:

[0151] S701, the network device may use the semi-persistent scheduling method of multicast to send the first multicast data to multiple terminal devices, that is, each terminal device can receive the first multicast data transmitted based on the semi-persistent scheduling SPS of multicast. Exemplarily, Figure 7 shows 3 terminal devices, denoted as the first terminal device, the second terminal device, and the third terminal device. It should be noted that Figure 7 in it, the network device does not send the first multicast data 3 times, but only sends it once, and all three terminal devices can receive the multicast data. The first multicast data transmitted based on the semi-persistent scheduling SPS of multicast can be interpreted as "firstmulticast data using a multi-cast based SPS transmission".

[0152] Among them, the transmission based on the semi-persistent scheduling of multicast mainly includes the following transmission in the activation stage and the transmission after activation. The transmission in the activation stage requires the activation of the semi-persistent SPS transmission of multicast through DCI. The first multicast data sent by the network device in the activation stage can be understood as data with scheduling information, and the first multicast data sent by the network device after activation can be understood as data without scheduling information or data without DCI.

[0153] In an alternative implementation manner, it corresponds to the implementation manner of A1 in the foregoing Solution 1. The network device may send a second DCI masked by a group configuration scheduling radio network temporary identity (G-CS-RNTI) to multiple terminal devices, and the second DCI is used to activate the multicast semi-persistent scheduling (SPS) transmission. Then, each terminal device may activate the multicast semi-persistent scheduling (SPS) transmission based on the second DCI, and further receive the foregoing first multicast data scheduled by the second DCI and subsequent first multicast data without scheduling information.

[0154] In another alternative implementation manner, it corresponds to the implementation manner of B1 in Solution 2. The network device may send a third DCI masked by a group radio network temporary identity (G-RNTI) to multiple terminal devices, and the third DCI is used to activate the multicast semi-persistent scheduling (SPS) transmission. At this time, the value of the first indication information included in the third DCI is a first value. Wherein, the value of the first indication information includes a first value or a second value, the first value is used to indicate the multicast semi-persistent scheduling (SPS) transmission, and the second value is used to indicate the multicast dynamic scheduling transmission. Optionally, the first indication information may be the target bit or the Identifier for DCI formats introduced in the foregoing Solution 2. The first value may be 0 and the second value may be 1; or, the first value may be 1 and the second value may be 0. Then, each terminal device may activate the multicast semi-persistent scheduling (SPS) transmission based on the third DCI, and further receive the foregoing first multicast data scheduled by the third DCI and subsequent first multicast data without scheduling information.

[0155] In addition, it should be noted that the third DCI does not include information for indicating whether the third DCI is used to schedule uplink transmission or downlink transmission. For example, when the target bit is used in the third DCI to indicate the multicast semi-persistent scheduling transmission or the multicast dynamic scheduling transmission, the Identifier for DCI formats is not included in the third DCI. When the Identifier for DCI formats is used in the third DCI to indicate the multicast semi-persistent scheduling transmission or the multicast dynamic scheduling transmission, the description or definition of the Identifier for DCI formats cannot be used to indicate whether the third DCI is used to schedule uplink transmission or downlink transmission.

[0156] Optionally, the new data indication (NDI) value in the second DCI is 0, indicating that the second DCI schedules initial transmission data; the new data indication (NDI) value in the third DCI is 0, indicating that the third DCI schedules initial transmission data.

[0157] S702. The network device receives a NACK as the feedback information from the first terminal device, that is, the first terminal device fails to successfully receive the foregoing first multicast data.

[0158] In S703, the network device sends a first DCI masked by CS-RNTI and first data to the first terminal device, where the first data is retransmitted data of first multicast data, and the first data can be understood as data transmitted based on unicast.

[0159] Optionally, the new data indication NDI value in the first DCI is 1, indicating that the first DCI schedules retransmitted data.

[0160] In addition, it should be noted that if the network device receives a relatively large number of NACK messages, for example, if the feedback messages received by the network device from the first terminal device and the second terminal device are both NACK, then based on the RNTI used in the foregoing activation phase, the network device can perform multicast retransmission scheduling based on G-CS-RNTI or G-RNTI, such as sending second multicast data, where the second multicast data is retransmitted data of the first multicast data, and the second multicast data can be understood as multicast data. The specific implementation manners can refer to the solutions in A2 and B2 above, and the embodiments of this application will not elaborate on this again.

[0161] In S704, the terminal device receives the first DCI and receives the first data according to the first DCI.

[0162] In the embodiments of this application, semi-persistent scheduling is adopted for multicast transmission, and there is no need to send scheduling information, that is, DCI, before sending multicast data each time, which can reduce the overhead of control signaling; and when an individual terminal device fails to successfully receive multicast data, the foregoing multicast data is retransmitted to the terminal device in a unicast manner instead of scheduling the retransmission of data in a multicast manner, which can further save the occupancy of downlink resources and improve the data transmission efficiency.

[0163] Further, when deactivating SPS transmission is required, the network device can also send a fourth DCI masked by G-RNTI or G-CS-RNTI to the terminal device, and the fourth DCI is used to deactivate the semi-persistent scheduling SPS transmission of the multicast. The content included in the fourth DCI can be implemented in the manner of A3 or B3 above, and this will not be elaborated on again.

[0164] Based on the same concept Figure 8Provided is a possible exemplary block diagram of the data transmission device involved in the present application, and the device 800 may exist in the form of software or hardware. The device 800 may include: a processing unit 802 and a communication unit 803. As an implementation manner, the communication unit 803 may include a receiving unit and a transmitting unit. The processing unit 802 is used to control and manage the operations of the device 800. The communication unit 803 is used to support the communication between the device 800 and other network entities. The device 800 may further include a storage unit 801, which is used to store the program code and data of the device 800.

[0165] Among them, the processing unit 802 may be a processor or a controller. For example, it may be a general central processing unit (CPU), a general processor, a digital signal processing (DSP), an application specific integrated circuits (ASIC), a field programmable gate array (FPGA) or other programmable logic devices, transistor logic devices, hardware components or any combination thereof. It can implement or execute various exemplary logic blocks, modules and circuits described in connection with the disclosure of the present application. The processor may also be a combination that implements computing functions, such as a combination of one or more microprocessors, a combination of a DSP and a microprocessor, and so on. The storage unit 801 may be a memory. The communication unit 803 is an interface circuit of the device, which is used to receive signals from other devices. For example, when the device is implemented in the form of a chip, the communication unit 803 is the interface circuit of the chip for receiving signals from other chips or devices, or is the interface circuit of the chip for transmitting signals to other chips or devices.

[0166] In one solution, the device 800 may be the terminal device in any of the above embodiments, or may also be a chip for a terminal device. For example, when the device 800 is a terminal device, the processing unit 802 may be a processor, and the communication unit 803 may be a transceiver. Optionally, the transceiver may include a radio frequency circuit, and the storage unit may be a memory. For example, when the device 800 is a chip for a terminal device, the processing unit 802 may be a processor, and the communication unit 803 may be an input / output interface, a pin, a circuit, etc. The processing unit 802 may execute computer-executable instructions stored in the storage unit. Optionally, the storage unit is a storage unit within the chip, such as a register, a cache, etc. The storage unit may also be a storage unit outside the chip within the terminal device, such as a read-only memory (ROM) or other types of static storage devices that can store static information and instructions, a random access memory (RAM), etc.

[0167] The following details the functions or operations performed by each unit within the device 800 when applied to a terminal device.

[0168] The communication unit 803 is configured to receive first multicast data transmitted based on semi-persistent scheduling (SPS) of multicast.

[0169] The communication unit 803 is further configured to receive first downlink control information (DCI), and the first DCI is masked by a configured scheduling radio network temporary identifier (CS-RNTI).

[0170] The processing unit 802 is configured to receive first data through the communication unit 803 according to the first DCI, and the first data is retransmitted data of the first multicast data.

[0171] In the embodiments of the present application, semi-persistent scheduling is used for multicast transmission, and there is no need to send scheduling information, i.e., DCI, before each transmission of multicast data, which can reduce the overhead of control signaling. Moreover, when retransmitting data to an individual terminal device, the foregoing multicast data is retransmitted to the terminal device in a unicast manner instead of scheduling the retransmission of data in a multicast manner, which can further save the occupancy of downlink resources and improve the data transmission efficiency.

[0172] In an optional implementation, before the communication unit 803 receives the first DCI, the processing unit 802 is further configured to determine that the reception of the first multicast data fails, and send feedback information such as NACK, and the feedback information is used to indicate that the reception of the first multicast data fails.

[0173] In an alternative embodiment, the communication unit 803 is further configured to: receive a second DCI masked by a group configuration scheduling radio network temporary identity (G-CS-RNTI), where the second DCI is used to activate the semi-persistent scheduling (SPS) transmission of the multicast.

[0174] In an alternative embodiment, the communication unit 803 is further configured to: receive a third DCI masked by a group radio network temporary identity (G-RNTI), where the third DCI is used to activate the semi-persistent scheduling (SPS) transmission of the multicast, and a first indication information included in the third DCI takes a first value, where the first indication information takes a value including a first value or a second value, the first value is used to indicate the semi-persistent scheduling (SPS) transmission of the multicast, and the second value is used to indicate the dynamic scheduling transmission of the multicast.

[0175] In an alternative embodiment, the third DCI does not include information for indicating whether the third DCI is used to schedule an uplink transmission or a downlink transmission.

[0176] In an alternative embodiment, the new data indication (NDI) value in the first DCI is 1; the new data indication (NDI) value in the second DCI is 0; and the new data indication (NDI) value in the third DCI is 0.

[0177] In an alternative embodiment, the communication module is further configured to: receive a fourth DCI masked by a group radio network temporary identity (G-RNTI), where the fourth DCI is used to deactivate the semi-persistent scheduling (SPS) transmission of the multicast; or receive a fourth DCI masked by a group configuration scheduling radio network temporary identity (G-CS-RNTI), where the fourth DCI is used to deactivate the semi-persistent scheduling (SPS) transmission of the multicast.

[0178] In another solution, the device 800 may be the network device in any of the above embodiments, or may also be a chip for a network device. For example, when the device 800 is a network device, the processing unit 802 may be a processor, and the communication unit 803 may be a transceiver. Optionally, the transceiver may include a radio frequency circuit, and the storage unit may be a memory. For example, when the device 800 is a chip for a network device, the processing unit 802 may be a processor, and the communication unit 803 may be an input / output interface, a pin, a circuit, etc. The processing unit 802 can execute the computer-executable instructions stored in the storage unit. Optionally, the storage unit is a storage unit within the chip, such as a register, a cache, etc. The storage unit may also be a storage unit outside the chip within the network device, such as a read-only memory (ROM) or other types of static storage devices that can store static information and instructions, a random access memory (RAM), etc.

[0179] The following details the functions or operations performed by each unit within the device 800 when applied to a network device.

[0180] The processing unit 802 is used to generate a first multicast data for semi-persistent scheduling (SPS) transmission based on multicast.

[0181] The communication unit 803 is used to send the first multicast data.

[0182] The communication unit 803 is further used to send a first downlink control information (DCI). The first DCI is masked by a configured scheduling radio network temporary identifier (CS-RNTI), and the first DCI is used to schedule first data, where the first data is the retransmission data of the first multicast data.

[0183] In the embodiments of the present application, when using semi-persistent scheduling for multicast transmission, there is no need to send scheduling information, i.e., DCI, before sending multicast data each time, which can reduce the overhead of control signaling. And when retransmitting data to individual terminal devices, the foregoing multicast data is retransmitted to the terminal device in a unicast manner instead of scheduling the retransmission of data in a multicast manner, which can further save the occupancy of downlink resources and improve the data transmission efficiency.

[0184] In an optional implementation manner, the communication unit 803 is further used to: send a second DCI masked by a group-configured scheduling radio network temporary identifier (G-CS-RNTI), where the second DCI is used to activate the semi-persistent scheduling (SPS) transmission of the multicast.

[0185] In an alternative embodiment, the communication unit 803 is further configured to: send a third DCI masked by a group radio network temporary identity (G-RNTI), where the third DCI is used to activate the semi-persistent scheduling (SPS) transmission of the multicast, and a first indication information included in the third DCI takes a first value. Here, the first indication information includes a first value or a second value, the first value is used to indicate the SPS transmission of the multicast, and the second value is used to indicate the dynamic scheduling transmission of the multicast.

[0186] In an alternative embodiment, the third DCI does not include information for indicating whether the third DCI is used to schedule uplink transmission or downlink transmission.

[0187] In an alternative embodiment, the new data indication (NDI) value in the first DCI is 1; the NDI value in the second DCI is 0; the NDI value in the third DCI is 0.

[0188] In an alternative embodiment, the communication unit 803 is further configured to: send a fourth DCI masked by a group radio network temporary identity (G-RNTI), where the fourth DCI is used to deactivate the SPS transmission of the multicast; or send a fourth DCI masked by a group configured scheduling radio network temporary identity (G-CS-RNTI), where the fourth DCI is used to deactivate the SPS transmission of the multicast.

[0189] As Figure 9 shown, a schematic diagram of a communication device provided by the present application is shown. The device may be the terminal device or the network device in the above embodiments. The device 900 includes: a processor 902, a communication interface 903, and a memory 901. Optionally, the device 900 may further include a communication line 904. Among them, the communication interface 903, the processor 902, and the memory 901 may be interconnected through the communication line 904; the communication line 904 may be a peripheral component interconnect (PCI) bus or an extended industry standard architecture (EISA) bus, etc. The communication line 904 may be divided into an address bus, a data bus, a control bus, etc. For ease of representation, Figure 9 only a thick line is shown in the figure, but it does not mean that there is only one bus or one type of bus.

[0190] The processor 902 may be a CPU, a microprocessor, an ASIC, or one or more integrated circuits for controlling the execution of the program of the present application solution.

[0191] The communication interface 903 uses any device such as a transceiver for communicating with other devices or communication networks, such as Ethernet, radio access network (RAN), wireless local area networks (WLAN), wired access networks, etc.

[0192] The memory 901 can be a ROM or other types of static storage devices that can store static information and instructions, a RAM or other types of dynamic storage devices that can store information and instructions, or can also be an electrically erasable programmable read-only memory (EEPROM), a compact disc read-only memory (CD-ROM), or other optical disc storage, optical disc storage (including compact discs, laser discs, optical discs, digital versatile discs, Blu-ray discs, etc.), magnetic disk storage media, or any other medium that can be used to carry or store the desired program code in the form of instructions or data structures and can be accessed by a computer, but is not limited thereto. The memory can exist independently and be connected to the processor through the communication line 904. The memory can also be integrated with the processor.

[0193] Among them, the memory 901 is used to store computer execution instructions for implementing the solution of this application, and is controlled by the processor 902 to execute. The processor 902 is used to execute the computer execution instructions stored in the memory 901, thereby implementing the data transmission method provided in the above embodiments of this application.

[0194] Optionally, the computer execution instructions in the embodiments of this application can also be referred to as application code, and the embodiments of this application do not make specific limitations thereon.

[0195] See Figure 10 , the embodiments of this application also provide another communication device 1000, which is a chip system and includes: an input / output interface 1010 and a logic circuit 1020.

[0196] When the communication device 1000 is a chip system in a terminal device, in some embodiments of the present application, the logic circuit 1020 and the input / output interface 1010 can be used to perform functions or operations executed by the above terminal device, etc. Exemplarily, the input / output interface 1010 is used to input first multicast data for semi-persistent scheduling (SPS) transmission based on multicast; the input / output interface 1010 is further used to input first downlink control information (DCI), and the first DCI is masked by a configured scheduling radio network temporary identity (CS-RNTI); the logic circuit 1020 is used to obtain first data through the input / output interface 1010 according to the first DCI, and the first data is retransmission data of the first multicast data. Optionally, before the input / output interface 1010 inputs the first DCI, the logic circuit 1020 is further used to determine a reception failure of the first multicast data and output feedback information such as NACK, and the feedback information is used to indicate the reception failure of the first multicast data.

[0197] When the communication device 1000 is a chip system in a network device, in some embodiments of the present application, the logic circuit 1020 and the input / output interface 1010 can be used to perform functions or operations executed by the above network device, etc. The logic circuit 1020 is used to generate first multicast data; the input / output interface 1010 is used to output the first multicast data, and the first multicast data is for semi-persistent scheduling (SPS) transmission based on multicast; the input / output interface 1010 is further used to output first downlink control information (DCI), and the first DCI is masked by a configured scheduling radio network temporary identity (CS-RNTI), and the first DCI is used to schedule first data, and the first data is retransmission data of the first multicast data.

[0198] Since the communication device 1000 provided in this embodiment can be applied to a terminal device to execute the method executed by the above terminal device, or applied to a network device to execute the method executed by the above network device. Therefore, the technical effects that can be obtained can refer to the above method embodiments and will not be elaborated here.

[0199] Based on the above embodiments, an embodiment of the present application further provides a communication system, which includes at least one communication device applied to a network device and at least one communication device applied to a terminal device. The technical effects that can be obtained can refer to the above method embodiments and will not be elaborated here.

[0200] Based on the above embodiments, the embodiments of the present application further provide a computer-readable storage medium, which stores computer programs or instructions. When the instructions are executed, the methods executed by the network device in any of the above embodiments, or the methods executed by the positioning management device in any of the above embodiments, or the methods executed by the terminal device in any of the above embodiments are implemented. The computer-readable storage medium may include: various media that can store program codes, such as USB flash drives, mobile hard disks, read-only memories, random access memories, magnetic disks, or optical discs.

[0201] To implement the functions of the above Figures 9 - 10 communication device, the embodiments of the present application further provide a chip, including a processor, which is used to support the communication device to implement the functions involved in the network device or the terminal device in the above method embodiments. In a possible design, the chip is connected to a memory or the chip includes a memory, and the memory is used to store the necessary computer programs or instructions and data of the communication device.

[0202] The present application is described with reference to the flowcharts and / or block diagrams of methods, devices (systems), and computer program products according to the embodiments of the present application. It should be understood that each process and / or block in the flowchart and / or block diagram, and the combination of processes and / or blocks in the flowchart and / or block diagram can be implemented by computer programs or instructions. These computer programs or instructions can be provided to the processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing devices to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing devices generate a device for implementing the specified functions in Figure 1 one process or multiple processes and / or blocks Figure 1 one block or multiple blocks.

[0203] Those skilled in the art should understand that the embodiments of the present application can be provided as a method, a system, or a computer program product. In the above embodiments, it can be implemented in whole or in part by software, hardware, firmware, or any combination thereof. When implemented using software, it can be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, the processes or functions described in the embodiments of the present application are generated in whole or in part. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable devices. The computer instructions can be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another. For example, the computer instructions can be transmitted from one website, computer, server, or data center to another website, computer, server, or data center by wire (such as coaxial cable, optical fiber, digital subscriber line (DSL)) or wireless (such as infrared, wireless, microwave, etc.). The computer-readable storage medium can be any available medium that can be accessed by a computer or a data storage device such as a server or a data center that includes one or more available media integrated. The available medium can be a magnetic medium (such as a floppy disk, a hard disk, a magnetic tape), an optical medium (such as a DVD), or a semiconductor medium (such as a solid state disk (SSD)), etc.

[0204] In the embodiments of the present application, the various illustrative logical units and circuits described can be implemented or operated to perform the described functions by a design of a general-purpose processor, a digital signal processor, an application specific integrated circuit (ASIC), a field programmable gate array (FPGA), or other programmable logic devices, discrete gate or transistor logic, discrete hardware components, or any combination of the above. The general-purpose processor can be a microprocessor. Optionally, the general-purpose processor can also be any conventional processor, controller, microcontroller, or state machine. The processor can also be implemented by a combination of computing devices, such as a digital signal processor and a microprocessor, multiple microprocessors, one or more microprocessors combined with a digital signal processor core, or any other similar configuration.

[0205] The steps of the methods or algorithms described in the embodiments of this application can be directly embedded in hardware, software units executed by a processor, or a combination of both. The software units can be stored in a RAM memory, flash memory, ROM memory, EPROM memory, EEPROM memory, register, hard disk, removable disk, CD-ROM, or any other form of storage medium in the art. Exemplarily, the storage medium can be connected to the processor so that the processor can read information from the storage medium and write information to the storage medium. Optionally, the storage medium can also be integrated into the processor. The processor and the storage medium can be provided in an ASIC.

[0206] These computer program instructions can also be loaded onto a computer or other programmable data processing device, so that a series of operation steps are executed on the computer or other programmable device to generate a computer-implemented process. Thus, the instructions executed on the computer or other programmable device provide steps for implementing the functions specified in Figure 1 one process or multiple processes and / or Figure 1 boxes or multiple boxes.

[0207] Although this application has been described in conjunction with specific features and their embodiments, it is obvious that various modifications and combinations can be made without departing from the concept and scope of this application. Accordingly, this specification and the drawings are only exemplary descriptions of this application defined by the appended claims, and are considered to cover any and all modifications, variations, combinations, or equivalents within the scope of this application. Obviously, those skilled in the art can make various changes and modifications to this application without departing from the scope of this application. Thus, if these modifications and variations of this application fall within the scope of the claims of this application and their equivalent technologies, this application is also intended to include these changes and modifications.

Claims

1. A data transmission method, characterized in that, Comprising: Receiving first multicast data for a multicast-based semi-persistent scheduling (SPS) transmission; Receiving first downlink control information (DCI) masked by a configured scheduling radio network temporary identifier (CS-RNTI) for identifying unicast transmission; Receiving first data according to the first DCI, where the first data is retransmission data of the first multicast data and is transmitted in a unicast manner.

2. The method according to claim 1, characterized in that, The method further comprises: Receiving second DCI masked by a group-configured scheduling radio network temporary identifier (G-CS-RNTI) for activating the multicast-based semi-persistent scheduling (SPS) transmission.

3. The method according to claim 1, characterized in that The method further comprises: Receiving third DCI masked by a group radio network temporary identifier (G-RNTI) for activating the multicast-based semi-persistent scheduling (SPS) transmission, where a first indication information included in the third DCI takes a first value, and the first indication information takes values including a first value or a second value, the first value is used to indicate multicast-based semi-persistent scheduling (SPS) transmission, and the second value is used to indicate multicast dynamic scheduling transmission.

4. The method according to claim 3, wherein: The third DCI does not include information for indicating whether the third DCI is for scheduling uplink transmission or downlink transmission.

5. The method according to claim 2, wherein The new data indication (NDI) value in the first DCI is 1, and the new data indication (NDI) value in the second DCI is 0.

6. The method according to claim 3, wherein The new data indication (NDI) value in the first DCI is 1, and the new data indication (NDI) value in the third DCI is 0.

7. The method according to any one of claims 1-6, characterized in that, The method further comprises: Receiving fourth DCI masked by a group radio network temporary identifier (G-RNTI) for deactivating the multicast-based semi-persistent scheduling (SPS) transmission; or Receiving fourth DCI masked by a group-configured scheduling radio network temporary identifier (G-CS-RNTI) for deactivating the multicast-based semi-persistent scheduling (SPS) transmission.

8. A data transmission method, characterized in that, Comprising: Transmitting first multicast data for a multicast-based semi-persistent scheduling (SPS) transmission; Transmitting first downlink control information (DCI) masked by a configured scheduling radio network temporary identifier (CS-RNTI) for identifying unicast transmission, where the first DCI is used to schedule first data, and the first data is retransmission data of the first multicast data and is transmitted in a unicast manner.

9. The method according to claim 8, characterized in that, The method further comprises: Transmitting second DCI masked by a group-configured scheduling radio network temporary identifier (G-CS-RNTI) for activating the multicast-based semi-persistent scheduling (SPS) transmission.

10. The method according to claim 8, wherein The method further comprises: Transmitting third DCI masked by a group radio network temporary identifier (G-RNTI) for activating the multicast-based semi-persistent scheduling (SPS) transmission, where a first indication information included in the third DCI takes a first value, and the first indication information takes values including a first value or a second value, the first value is used to indicate multicast-based semi-persistent scheduling (SPS) transmission, and the second value is used to indicate multicast dynamic scheduling transmission.

11. The method according to claim 10, wherein the third DCI does not contain information for indicating that the third DCI is used for scheduling uplink transmission or downlink transmission.

12. The method according to claim 9, wherein The new data indication NDI value in the first DCI is 1, and the new data indication NDI value in the second DCI is 0.

13. The method according to claim 10, characterized in that, The new data indication NDI value in the first DCI is 1, and the new data indication NDI value in the third DCI is 0.

14. The method according to any one of claims 8-13, characterized in that, The method further includes: sending a fourth DCI masked by a group radio network temporary identifier G-RNTI, where the fourth DCI is used to deactivate the semi-persistent scheduling SPS transmission of the multicast; or, sending a fourth DCI masked by a group configured scheduling radio network temporary identifier G-CS-RNTI, where the fourth DCI is used to deactivate the semi-persistent scheduling SPS transmission of the multicast.

15. A data transmission device, characterized in that, including: a communication unit, configured to receive first multicast data for semi-persistent scheduling SPS transmission based on multicast; the communication unit is further configured to receive a first downlink control information DCI, where the first DCI is masked by a configured scheduling radio network temporary identifier CS-RNTI, and the CS-RNTI is used to identify unicast transmission; a processing unit, configured to receive first data through the communication unit according to the first DCI, where the first data is retransmitted data of the first multicast data, and the first data is transmitted in a unicast manner.

16. The device according to claim 15, characterized in that, The communication unit is further configured to: receive a second DCI masked by a group configured scheduling radio network temporary identifier G-CS-RNTI, where the second DCI is used to activate the semi-persistent scheduling SPS transmission of the multicast.

17. The device according to claim 15, characterized in that The communication unit is further configured to: receive a third DCI masked by a group radio network temporary identifier G-RNTI, where the third DCI is used to activate the semi-persistent scheduling SPS transmission of the multicast, and a first indication information value included in the third DCI takes a first value, where the first indication information value includes a first value or a second value, the first value is used to indicate the semi-persistent scheduling SPS transmission of the multicast, and the second value is used to indicate the dynamic scheduling transmission of the multicast.

18. The device according to claim 17, characterized in that, The third DCI does not contain information for indicating that the third DCI is used for scheduling uplink transmission or downlink transmission.

19. The device according to claim 16, characterized in that The new data indication NDI value in the first DCI is 1, and the new data indication NDI value in the second DCI is 0.

20. The device according to claim 17, characterized in that, The new data indication NDI value in the first DCI is 1, and the new data indication NDI value in the third DCI is 0.

21. The device according to any one of claims 15-20, characterized in that, The communication unit is further configured to: receive a fourth DCI masked by a group radio network temporary identifier G-RNTI, where the fourth DCI is used to deactivate the semi-persistent scheduling SPS transmission of the multicast; or, receive a fourth DCI masked by a group configured scheduling radio network temporary identifier G-CS-RNTI, where the fourth DCI is used to deactivate the semi-persistent scheduling SPS transmission of the multicast.

22. A data transmission device, characterized in that, including: a processing unit, configured to generate first multicast data for semi-persistent scheduling SPS transmission based on multicast; a communication unit, configured to send the first multicast data; The communication unit is further configured to send a first downlink control information (DCI). The first DCI is masked by a configured scheduling radio network temporary identity (CS-RNTI). The CS-RNTI is used to identify unicast transmission. The first DCI is used to schedule first data, and the first data is retransmitted data of first multicast data, and the first data is transmitted in a unicast manner.

23. The device according to claim 22, wherein, The communication unit is further configured to: send a second DCI masked by a group-configured scheduling radio network temporary identity (G-CS-RNTI), where the second DCI is used to activate semi-persistent scheduling (SPS) transmission of the multicast.

24. The device according to claim 22, wherein, The communication unit is further configured to: send a third DCI masked by a group radio network temporary identity (G-RNTI), where the third DCI is used to activate semi-persistent scheduling (SPS) transmission of the multicast. A value of first indication information included in the third DCI is a first value. Wherein, the value of the first indication information includes a first value or a second value. The first value is used to indicate semi-persistent scheduling (SPS) transmission of the multicast, and the second value is used to indicate dynamic scheduling transmission of the multicast.

25. The device according to claim 24, wherein, The third DCI does not include information for indicating whether the third DCI is used to schedule uplink transmission or downlink transmission.

26. The device according to claim 23, characterized in that, A new data indication (NDI) value in the first DCI is 1, and a new data indication (NDI) value in the second DCI is 0.

27. The device according to claim 24, wherein A new data indication (NDI) value in the first DCI is 1, and a new data indication (NDI) value in the third DCI is 0.

28. The device according to any one of claims 22-27, characterized in that, The communication unit is further configured to: send a fourth DCI masked by a group radio network temporary identity (G-RNTI), where the fourth DCI is used to deactivate semi-persistent scheduling (SPS) transmission of the multicast; or send a fourth DCI masked by a group-configured scheduling radio network temporary identity (G-CS-RNTI), where the fourth DCI is used to deactivate semi-persistent scheduling (SPS) transmission of the multicast.

29. A communication device, characterized in that, including: a processor, the processor is coupled with a memory. The memory is used to store computer programs or instructions, and the processor is used to execute the computer programs or instructions to implement the method according to any one of claims 1-7 or the method according to any one of claims 8-14.

30. A computer-readable storage medium, characterized in that A computer program or instruction is stored on the computer-readable storage medium. When the instruction runs on a computer, the method according to any one of claims 1-7 or the method according to any one of claims 8-14 is implemented.

31. A computing program product, characterized in that, including computer instructions. When the computer instructions run on a computer, the computer is caused to execute the method according to any one of claims 1-7 or claims 8-14.

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